Sustainable Solution For Red Tides, Toxic Algae Blooms That Kill Fish - Man Made Sewage Treatment Wetlands Marsh. Which Removes Excess Nitrogen, Phosphorus, Potassium (NPK), Ammonia, Heavy Metals From Grey Or Black Water
THE WAR ON NATURE AND ENVIRONMENT CONTINUES AND ACCELERATES UNDER TRUMP
The war against Nature and all living things continues and accelerates under Trump.
Trump′s lasting damage to the environment | Environment| All topics from climate change to conservation | DW |
This week, it was announced that copper and cobalt mining will begin in the formerly protected federal US lands of Grand Staircase-Escalante National Monument of Utah. The mining is now possible after Donald Trump removed protection from 2.2 million acres of federal land in Utah — the largest elimination of protected areas in US history.
It is only a fraction of the protections Trump has removed from federal lands since taking office in January 2017 — part of a general campaign promise to dismantle American environmental law, which Trump says is stifling economic growth.
The promises were not only made in campaign stump speeches. They were also set in the official Republican Party Platform adopted at the party’s convention in August 2016. “The environmental establishment has become a self-serving elite, stuck in the mindset of the 1970s,” the platform stated. “Their approach is based on shoddy science, scare tactics, and centralized command-and-control regulation.”
What is this meme pointing at? The following speaker ties in red tides, the dying oceans and fish plus much more..
Life Changing Videos is with Kindness Trust. Wow. This speech by Philip Wollen took our breath away.
VIDEO: https://www.facebook.com/garytvcom/videos/1315715418565207/Environmental Casualties of Trump’s Trade War | Sierra Club
Water pollution: By far the biggest casualty in Trump’s trade war is the soybean trade. China used to buy some 60 percent of the U.S. crop, but sales have plummeted since China’s imposition of retaliatory tariffs. Trump is trying to soften the blow to the politically powerful soybean industry by having U.S. taxpayers subsidize them to the tune of $3.6 billion.
An unexpected environmental effect of a drop in soybean production, according to a study by the Northeast Midwest Institute, could be increased nitrate pollution of drinking water sources. Nitrates enter the soil primarily as a result of fertilizers used on corn, but many farmers cycle it by also planting soybeans, which absorb the nitrates. No soybeans to absorb the nitrates, though, means more nitrate runoff into rivers and streams. As the price of U.S. soybeans plummets, it makes less sense for farmers to grow them. Subsequently, the nitrate pollution in source water will only continue to escalate.
Expensive solar panels: In January, even before the trade war really got going, the Trump administration imposed a 30 percent tariff on Chinese solar panels. That was followed in June by an additional 25 percent levy. The effect has not been enormous, given that many U.S. solar installers saw the writing on the wall and stockpiled cheap units in advance of the trade spat. Also, Chinese imports only represent about 10 percent of the solar market: Malaysia, South Korea, and Vietnam all have larger chunks of the pie. The Energy Information Administration projects that solar generation will increase by 23 percent this year over last.
TRUMP PROMOTES QUACK HORMESIS THEORY OF 'CLEAN COAL' AND 'CLEAN NUCLEAR'
Trump promotes the 'clean coal' conspiracy theory that no one believes except for coal industry promoters and those who believe pro toxic corporate emissions propaganda, which is aired on corporate friendly mass media such as Fox News.
How the Trump administration is rolling back plans for clean power | Environment | The Guardian
The US is the world’s second largest emitter of greenhouse gas emissions and, under Trump, has vowed to step away from the Paris deal and tear up various climate-related regulations.
If the country doesn’t force down its planet-warming gases coming from power plants, vehicles, agriculture and other sources, the world is far more likely to careen into a challenging new climate marked by severe heatwaves, storms, flooding and displacement of millions of people.Trump is also promoting the conspiracy theory that global warming does not exist.. despite a literal almost 100 percent consensus of climate scientists all around the world agreeing that human caused global warming exists and is accelerating.
Even the fossil fuel industry KNOWS about global warming caused by humans, but it is covering this up via huge donations to 200 global warming and climate change denying organizations globally.
AGRICULTURAL AND CITY SEWAGE DISCHARGES CAUSE MASSIVE DEAD ZONES IN THE WORLD'S OCEANS
Humanity is waging a war AGAINST Nature, by opposing all natural systems and processes, including waste water treatment systems. Anything not sustainable is TERMINAL.
Sewage treatment plants that use massive amounts of chemicals and an industrial process have HUGE downsides. One downside and consequence is massive costs, and huge amounts of toxic poisonous chemicals used, but they generate huge profits for the chemical industry, so any natural chemical free methods are resisted by them and their lobbyists.
Another huge negative consequence is the growing and expanding amount of dead zones in both fresh and saltwater due to toxic algae and 'red tides' which smell bad, are toxic to all life and kill everything that they touch in some cases.
Sewage treatment plants that use massive amounts of chemicals and an industrial process have HUGE downsides. One downside and consequence is massive costs, and huge amounts of toxic poisonous chemicals used, but they generate huge profits for the chemical industry, so any natural chemical free methods are resisted by them and their lobbyists.
Another huge negative consequence is the growing and expanding amount of dead zones in both fresh and saltwater due to toxic algae and 'red tides' which smell bad, are toxic to all life and kill everything that they touch in some cases.
Dead Zones In World's Oceans And Large Lakes Growing, Close To 2 Million Square Miles Globally
https://www.agreenroadjournal.com/2014/06/2014-dead-zones-in-worlds-oceans-and.html
Huge factory farms discharge massive amounts of toxic algae creating sewage water into fresh and salt water.
Huge factory farms discharge massive amounts of toxic algae creating sewage water into fresh and salt water.
Huge Subsidized Factory Farms Raising Animals Cause Global Warming, Degraded 14 Billion Acres of Pastureland And Grassland - Chemical Agribusiness Kills Soil, Drains Nutrients Out Of Soil, Food Grown With Chemicals Degrades Human Health
Another huge negative consequence is that all of the artificial man created chemicals and toxic drugs plus poisons going through homes, farms, factory farms, and humans end up in the sewage treatment process, and then they end up in the fresh and salt water. But the best chemical 'treatment' available only removes a small fraction of these poisons and toxic materials from the water.
Only Half of Drugs Removed by Sewage Treatment
Only about half of the prescription drugs and other newly emerging contaminants in sewage are removed by treatment plants says a new report
Factory Farm And Medical Overuse Of Antibiotics Use Creates 2 Million SuperBug Infections Like MSRA, And 23,000 Deaths Each Year; List Of Natural Antibiotics And Anti Viral Modalities, Price Comparison Engine, Miracle Drug Turning Into Nightmare Horror Story
Let's ask the question; What works for this and seven future generations without causing harm?
There is a way to prevent or solve almost all of these problems, and that is by working in harmony with Nature, instead of fighting it.
WHAT IS A SEWAGE TREATMENT WETLAND?
SEWAGE TREATMENT WETLAND
Wikipedia; "Constructed wetland in an ecological settlement in Flintenbreite near Lübeck, Germany
A constructed wetland (CW) is an artificial wetland to treat municipal or industrial wastewater, greywater or stormwater runoff. It may also be designed for land reclamation after mining, or as a mitigationstep for natural areas lost to land development.
Constructed wetlands are engineered systems that use natural functions vegetation, soil, and organisms to treat wastewater. Depending on the type of wastewater the design of the constructed wetland has to be adjusted accordingly. Constructed wetlands have been used to treat both centralized and on-site wastewater. Primary treatment is recommended when there is a large amount of suspended solids or soluble organic matter (measured as BOD and COD).[1]
Similarly to natural wetlands, constructed wetlands also act as a biofilter and/or can remove a range of pollutants (such as organic matter, nutrients, pathogens, heavy metals) from the water. Constructed wetlands are a sanitation technology that have not been designed specifically for pathogen removal, but instead, have been designed to remove other water quality constituents such as suspended solids, organic matter and nutrients (nitrogen and phosphorus).[1] All types of pathogens (i.e., bacteria, viruses, protozoan and helminths) are expected to be removed to some extent in a constructed wetland. Subsurface wetland provide greater pathogen removal than surface wetlands.[1]
There are two main types of constructed wetlands: subsurface flow and surface flow constructed wetlands. The planted vegetation plays an important role in contaminant removal. The filter bed, consisting usually of sand and gravel, has an equally important role to play.[2] Some constructed wetlands may also serve as a habitat for native and migratory wildlife, although that is not their main purpose. Subsurface flow constructed wetlands are designed to have either horizontal flow or vertical flow of water through the gravel and sand bed. Vertical flow systems have a smaller space requirement than horizontal flow systems.
Source: http://en.wikipedia.org/wiki/Constructed_wetlandCHEMICAL FREE MICROORGANISM WASTEWATER TREATMENT TAKES OUT EXCESS NPK THAT CAUSES DEAD ZONES IN THE OCEAN
There are sustainable chemical free wastewater treatment methods
WHAT IS A CONSTRUCTED WETLAND?
What does an artificial chemical free wastewater treatment marsh look like?
According to Wikipedia; "A constructed wetland or wetpark is an artificial wetland created as a new or restored habitat for native and migratory wildlife, for anthropogenic discharge such as wastewater, stormwater runoff, or sewage treatment, for land reclamation after mining, refineries, or other ecological disturbances such as required mitigation for natural areas lost to a development. Natural wetlands act as a biofilter, removing sediments and pollutants such as heavy metals from the water, and constructed wetlands can be designed to emulate these features.
The pictures above are from an actual operating man made sewage treatment wetlands facility in Petaluma, CA. The birds and other wildlife that are attracted to this kind of man made operation really seem to really love it.
WHAT IS BIOFILTRATION?
Biofiltration
Wikipedia; "Vegetation in a wetland provides a substrate (roots, stems, and leaves) upon which microorganisms can grow as they break down organic materials. This community of microorganisms is known as the periphyton. The periphyton and natural chemical processes are responsible for approximately 90 percent of pollutant removal and waste breakdown. The plants remove about seven to ten percent of pollutants, and act as a carbonsource for the microbes when they decay. Different species of aquatic plants have different rates of heavy metal uptake, a consideration for plant selection in a constructed wetland used for water treatment. Constructed wetlands are of two basic types: subsurface-flow and surface-flow wetlands.
Newly planted constructed wetland.
Same constructed wetland, two years later.
Wetlands types
See also General application below
Natural wetlands
Subsurface-flow wetlands
Subsurface-flow wetlands can be further classified as horizontal flow and vertical flow constructed wetlands. Subsurface-flow wetlands move effluent (household wastewater, agricultural, paper mill wastewater [1][2] or mining runoff, tannery or meat processing wastes, or storm drains, or other water to be cleansed) through a gravel (generally limestone or volcanic rock lavastone) or sand medium on which plants are rooted. In subsurface-flow systems, the effluent may move either horizontally, parallel to the surface, or vertically, from the planted layer down through the substrate and out. Subsurface horizontal-flow wetlands are less hospitable to mosquitoes, (as there is no water exposed to the surface) whose populations can be a problem in surface-flow constructed wetlands. Carnivorous plants have been used to address this problem.[citation needed] Subsurface-flow systems have the advantage of requiring less land area for water treatment, but are not generally as suitable for wildlife habitat as are surface-flow constructed wetlands.
Surface-flow wetlands
Surface-flow wetlands move effluent above the soil in a planted marsh or swamp, and thus can be supported by a wider variety of soil types includingbay mud and other silty clays.
Plantings of reedbeds are popular in European constructed wetlands, and plants such as cattails (Typha spp.), sedges, Water Hyacinth (Eichhornia crassipes) and Pontederia spp. are used worldwide (although Typha and Phragmites are highly invasive). Recent research in use of constructed wetlands for subarctic regions has shown that buckbeans (Menyanthes trifoliata) and pendant grass (Arctophila fulva) are also useful for metals uptake.
Tidal-flow wetlands
Tidal-flow wetlands are the latest evolution of wetland technology, used to treat domestic, agricultural & industrial wastewater, including heavy load. In this system, organic carbon is primarily oxidized with nitrate, which is produced through a series of flood and drain cycles, from one side of the wetland to the other. This process holds a number of benefits over traditional subsurface- and surface-flow wetlands including, reduced land requirements and increased de-nitrification capabilities for the treatment of heavy load.
General contaminants removal
Physical, chemical, and biological processes combine in wetlands to remove contaminants from wastewater. An understanding of these processes is fundamental not only to designing wetland systems but to understanding the fate of chemicals once they enter the wetland. Theoretically, wastewater treatment within a constructed wetland occurs as it passes through the wetland medium and the plant rhizosphere.
A thin film around each root hair is aerobic due to the leakage of oxygen from the rhizomes, roots, and rootlets.[3] Aerobic and anaerobic micro-organisms facilitate decomposition of organic matter. Microbial nitrification and subsequent denitrification releases nitrogen as gas to the atmosphere. Phosphorus is coprecipitated withiron, aluminium, and calcium compounds located in the root-bed medium.[4][5][6][7][8]
Suspended solids filter out as they settle in the water column in surface flow wetlands or are physically filtered out by the medium within subsurface flow wetland cells. Harmful bacteria and viruses are reduced by filtration and adsorption by biofilms on the rock media in subsurface flow and vertical flow systems.
Specific contaminants removal
Nitrogen removal
The dominant forms of nitrogen in wetlands that are of importance to wastewater treatment include organic nitrogen, ammonia, ammonium, nitrate,nitrite, and nitrogen gases. Inorganic forms are essential to plant growth in aquatic systems but if scarce can limit or control plant productivity.[9] Total Nitrogen refers to all nitrogen species. Wastewater nitrogen removal is important because of ammonia’s toxicity to fish if discharged into watercourses. Excessive nitrates in drinking water is thought to cause methemoglobinemia in infants, which decreases the blood's oxygen transport ability. The UK has experienced a significant increase in nitrate concentration in groundwater and rivers.[10]
Organic nitrogen
Mitsch Gosselink define nitrogen mineralisation as "the biological transformation of organically combined nitrogen to ammonium nitrogen during organic matter degradation".[11] This can be both an aerobic and anaerobic process and is often referred to as ammonification. Mineralisation of organically combined nitrogen releases inorganic nitrogen as nitrates, nitrites, ammonia and ammonium, making it available for plants, fungi and bacteria.[11] Mineralisation rates may be affected by oxygen levels in a wetland.[8]
Ammonia removal
(NH
3) and ammonium (NH+
4)
The formation of ammonia (NH
3) occurs via the mineralisation or ammonification of organic matter under either anaerobic or aerobic conditions.[12]The ammonium ion (NH+
4) is the primary form of mineralized nitrogen in most flooded wetland soils. This ion forms when ammonia combines with water as follows:
NH
3 + H
2O ⇌ NH+
4 + OH −[11]
Upon formation, several pathways are available to the ammonium ion. It can be absorbed by plants and algae and converted back into organic matter, or the ammonium ion can be electrostatically held on negatively charged surfaces of soil particles.[11] At this point, the ammonium ion can be prevented from further oxidation because of the anaerobic nature of wetland soils. Under these conditions the ammonium ion is stable and it is in this form that nitrogen predominates in anaerobic sediments typical of wetlands.[8][13]
Most wetland soils have a thin aerobic layer at the surface. As an ammonium ion from the anaerobic sediments diffuses upward into this layer it converts to nitrite or nitrified.[14] An increase in the thickness of this aerobic layer results in an increase in nitrification.[8] This diffusion of the ammonium ion sets up a concentration gradient across the aerobic-anaerobic soil layers resulting in further nitrification reactions.[8][14]
Nitrification is the biological conversion of organic and inorganic nitrogenous compounds from a reduced state to a more oxidized state.[15]Nitrification is strictly an aerobic process in which the end product is nitrate (NO−3); this process is limited when anaerobic conditions prevail.[8]Nitrification will occur readily down to 0.3 ppm dissolved oxygen.[12] The process of nitrification (1) oxidizes ammonium (from the sediment) to nitrite (NO−2), and then (2) nitrite is oxidized to nitrate (NO−3).
The overall nitrification reactions are as follows:
The overall nitrification reactions are as follows:
(1) 2NH+
4 + 3O
2 ⇌ 4H+ + 2H
2O + 2NO−
2
(2) 2NO−
2 + O
2 ⇌ 2NO−
3
(Davies Hart, 1990)
Two different bacteria are required to complete this oxidation of ammonium to nitrate. Nitrosomonas sp. oxidizes ammonium to nitrite via reaction (1), and Nitrobacter sp. oxidizes nitrite to nitrate via reaction (2).[12]
Denitrification is the biochemical reduction of oxidized nitrogen anions, nitrate (NO−3) and nitrite (NO−2) to produce the gaseous products nitric oxide (NO), nitrous oxide (N2O) and nitrogen gas (N2), with concomitant oxidation of organic matter.[15] The general sequence is as follows:
NO−
3 → NO−
2 → NO → N
2O → N
2
The end products, N2O and N2 are gases that re-enter the atmosphere. Denitrification occurs intensely in anaerobic environments but also in aerobic conditions.[16] Oxygen deficiency causes certain bacteria to use nitrate in place of oxygen as an electron acceptor for the reduction of organic matter.[8] Denitrification is restricted to a narrow zone in the sediment immediately below the aerobic-anaerobic soil interface.[11][17] Denitrification is considered to be the predominant microbial process that modifies the chemical composition of nitrogen in a wetland system and the major process whereby nitrogen is returned to the atmosphere (N2).[8][18] To summarize, the nitrogen cycle is completed as follows: ammonia in water, at or near neutral pH is converted to ammonium ions; the aerobic bacterium Nitrosomonas sp. oxidizes ammonium to nitrite; Nitrobacter sp. then converts nitrite to nitrate. Under anaerobic conditions, nitrate is reduced to relatively harmless nitrogen gas that enters the atmosphere.
Domestic sewage—ammonia
In a review of 19 surface flow wetlands it was found that nearly all reduced total nitrogen.[19] A review of both surface flow and subsurface flow wetlands concluded that effluent nitrate concentration is dependent on maintaining anoxic conditions within the wetland so that denitrification can occur and that subsurface flow wetlands were superior to surface flow wetlands for nitrate removal. The 20 surface flow wetlands reviewed reported effluent nitrate levels below 5 mg/L[20]
Results obtained from the Niagara-On-The-Lake vertical flow systems show a significant reduction in both total nitrogen and ammonia (> 97%) when primary treated effluent was applied at a rate of 60L/m²/day. Calculations showed that over 50% of the total nitrogen going into the system was converted to nitrogen gas. Effective removal of nitrate from the sewage lagoon influent was dependent on medium type used within the vertical cell as well as water table level within the cell.[21]
Mine water—ammonia
Constructed wetlands have been used to remove ammonia from mine drainage. In Ontario, Canada, drainage from the polishing pond at the Campbell Mine flows by gravity through a 9.3 hectare surface flow constructed wetland during the ice-free season.[22] Ammonia is removed by approximately 95% on inflows of up to 15,000 cubic metres (530,000 cu ft)/day during the summer months, while removal rates decrease to 50-70% removal during cold months. This ammonia was oxidized to nitrate, which was immediately and quantitatively removed in the wetland.
Surprisingly, and contrary to Reed (see above), anoxic conditions were not necessary for nitrate removal, which occurred as readily on leaf and detritus biofilm as it did in sediments. Other contaminants, including copper, are also removed in the wetland, such that the final discharge is fully detoxified. Campbell became one of the first gold mines in Ontario to produce a completely non-toxic discharge, as determined by acute and chronic toxicity tests. At the Ranger Uranium Mine, in Australia, ammonia is removed in "enhanced" natural wetlands (rather than fully engineered constructed wetlands), along with manganese, uranium and other metals.
Other mines use natural or constructed wetlands to remove nitrogenous compounds from contaminated mine water, including cyanide (at the Jolu and Star Lake Mines, using natural muskeg and wetlands) and nitrate (demonstrated at the Quinsam Coal Mine). Wetlands were also proposed to remove nitrogenous compounds (present as blasting residues) from diamond mines in Northern Canada. However, land application is equally effective and is easier to implement than a constructed wetland.
Phosphorus removal
Phosphorus occurs naturally in both organic and inorganic forms. The analytical measure of biologically available orthophosphates is referred to as soluble reactive phosphorus (SR-P). Dissolved organic phosphorus and insoluble forms of organic and inorganic phosphorus are generally not biologically available until transformed into soluble inorganic forms.[11]
In freshwater aquatic ecosystems phosphorus is typically the major limiting nutrient. Under undisturbed natural conditions, phosphorus is in short supply. The natural scarcity of phosphorus is demonstrated by the explosive growth of algae in water receiving heavy discharges of phosphorus-rich wastes. Because phosphorus does not have an atmospheric component, unlike nitrogen, the phosphorus cycle can be characterized as closed. The removal and storage of phosphorus from wastewater can only occur within the constructed wetland itself. Phosphorus may be sequestered within a wetland system by:
The binding of phosphorus in organic matter as a result of incorporation into living biomass,
Precipitation of insoluble phosphates with ferric iron, calcium, and aluminium found in wetland soils.[11]
Biomass plants incorporation—phosphorus
Higher plants in wetland systems may be viewed as transient nutrient storage compartments absorbing nutrients during the growing season and releasing them at senescence.[23][24] Generally, plants in nutrient-rich habitats accumulate more nutrients than those in nutrient-poor habitats, a phenomenon referred to as luxury uptake of nutrients.[23] Aquatic vegetation may play an important role in phosphorus removal and, if harvested, extend the life of a system by postponing phosphorus saturation of the sediments.[23][25][26]
Vascular plants may account for only a small amount of phosphorus uptake with only 5 to 20% of the nutrients detained in a natural wetland being stored in harvestable plant material. Bernard and Solsky also reported relatively low phosphorus retention, estimating that a sedge (Carex sp.) wetland retained 1.9 g of phosphorus per square meter of wetland.[24][27] Bulrushes (Scirpus sp.) in a constructed wetland system receiving secondarily treated domestic wastes contained 40.5% of the total phosphorus influent. The remaining 59.0% was found to be stored in the gravel substratum.[27] Phosphorus removal in a surface flow wetland treatment system planted with one of Scirpus sp., Phragmites sp. or Typha sp. was investigated by Finlayson and Chick (1983).
Phosphorus removal of 60%, 28%, and 46% were found for Scirpus sp., Phragmites sp. and Typha sp. respectively. This may prove to be a low estimate. Vascular plants are a major phosphorus storage compartment accounting for 67.3% of the influent phosphorus.[25] Plant adsorption may reach 80% phosphorus removal.[28]
The lack of seasonal fluctuation in phosphorus removal rates suggests that the primary mechanism is bacterial and alga fixation.[30] However, this mechanism may be temporary, because the microbial pool is small and quickly becomes saturated at which point the soil medium takes over as the major contributor to phosphate removal.[31]
Plants create a unique environment at the biofilm's attachment surface. Certain plants transport oxygen which is released at the biofilm/root interface, perhaps adding oxygen to the wetland system.[32] Plants also increase soil or other root-bed medium hydraulic conductivity. As roots and rhizomes grow they are thought to disturb and loosen the medium, increasing its porosity, which may allow more effective fluid movement in the rhizosphere. When roots decay they leave behind ports and channels known as macropores which are effective in channeling water through the soil.[33]
Whether or not wetland systems act as a phosphorus sink or source seems to depend on system characteristics such as sediment and hydrology. There seems to be a net movement of phosphorus into the sediment in many lakes.[34] In Lake Erie as much as 80% of the total phosphorus is removed from the waters by natural processes and is presumably stored in the sediment. Marsh sediments high in organic matter act as sinks.[14]
Phosphorus release from a marsh exhibits a cyclical pattern. Much of the spring phosphorus release comes from high phosphorus concentrations locked up in the winter ice covering the marsh; in summer the marsh acts as a phosphorus sponge.[14] Phosphorus is exported from the system following dieback of vascular plants.[35] Phosphorus concentrations in water are reduced during the growing season due to plant uptake but decomposition and subsequent mineralisation of organic matter releases phosphorus over the winter and accounts for the higher winter phosphorus concentrations in the marsh.[11][14]
Retention by soils or root-bed media—phosphorus
Two types of phosphate retention mechanisms may occur in soils or root-bed media: chemical adsorption onto the medium[36] and physical precipitation of the phosphate ion.[37] Both result from the attraction between phosphate ion and ions of Al, Fe or Ca [36][38] and terminates with formation of various iron phosphates (Fe-P), aluminum phosphates (Al-P) or calcium phosphates (Ca-P).[6]
Oxidation-reduction potential (ORP, formally reported as Eh) of soil or water is a measure of its ability to reduce or oxidize chemical substances and may range between -350 and +600 millivolts (mV). Though redox potential does not affect phosphorus' oxidation state, redox potential is indirectly important because of its effect on iron solubility (through reduction of ferric oxides). Severely reduced conditions in the sediments may result in phosphorus release,[39] Typical wetland soils may have an Eh of -200 mV.[40] Under these reduced conditions Fe+3 (Ferric iron) in insoluble ferric oxides may be reduced to soluble Fe+2 (Ferrous iron).
Any phosphate ion bound to the ferric oxide may be released back into solution as it dissolves[7][37] However, the Fe+2 diffusing in the water column may be re-oxidized to Fe+3 and re-precipitated as an iron oxide when it encounters oxygenated surface water. This precipitation reaction may remove phosphate from the water column and deposit it back on the surface of sediments .[15] Thus, there can be a dynamic uptake and release of phosphorus in sediments that is governed by the amount of oxygen in the water column. A well documented occurrence in the hypolimnion of lakes is the release of soluble phosphorus when conditions become anaerobic.[41][42] This phenomenon also occurs in natural wetlands. Oxygen concentrations of less than 2.0 mg/l result in the release of phosphorus from sediments.[43][44]
Any phosphate ion bound to the ferric oxide may be released back into solution as it dissolves[7][37] However, the Fe+2 diffusing in the water column may be re-oxidized to Fe+3 and re-precipitated as an iron oxide when it encounters oxygenated surface water. This precipitation reaction may remove phosphate from the water column and deposit it back on the surface of sediments .[15] Thus, there can be a dynamic uptake and release of phosphorus in sediments that is governed by the amount of oxygen in the water column. A well documented occurrence in the hypolimnion of lakes is the release of soluble phosphorus when conditions become anaerobic.[41][42] This phenomenon also occurs in natural wetlands. Oxygen concentrations of less than 2.0 mg/l result in the release of phosphorus from sediments.[43][44]
Domestic sewage—phosphorus
Adsorption to binding sites within sediments was the major phosphorus removal mechanism in the surface flow constructed wetland system at Port Perry, Ontario[45] Release of phosphorus from the sediments occurred when anaerobic conditions prevailed. The lowest wetland effluent phosphorus levels occurred when oxygen levels of the overlying water column were above 1.0 mg / L. Removal efficiencies for total phosphorus were 54-59% with mean effluent levels of 0.38 mg P/L. Wetland effluent phosphorus concentration was higher than influent levels during the winter months.
The phosphorus removed in a VF wetland in Australia over a short term was stored in the following wetland components in order of decreasing importance: substratum> macrophyte >biofilm, but over the long term phosphorus storage was located in macrophyte> substratum>biofilm components. Medium iron-oxide adsorption provides additional removal for some years.[46]
A comparison of phosphorus removal efficiency of two large-scale, surface flow wetland systems in Australia which had a gravel substratum to laboratory phosphorus adsorption indicated that for the first two months of wetland operation, the mean phosphorus removal efficiency of system 1 and 2 was 38% and 22%, respectively. Over the first year a decline in removal efficiencies occurred. During the second year of operation more phosphorus came out than was put in. This release was attributed to the saturation of phosphorus binding sites. Close agreement was found between the phosphorus adsorption capacity of the gravel as determined in the laboratory and the adsorption capacity recorded in the field.
The phosphorus adsorption capacity of a subsurface flow constructed wetland system containing a predominantly quartz gravel in the laboratory using the Langmuir adsorption isotherm was 25 mg P/g gravel.[25] Close agreement between calculated and realized phosphorus adsorption was found. The poor adsorption capacity of the quartz gravel implied that plant uptake and subsequent harvesting were the major phosphorus removal mechanism.[47]
Metals removal
Constructed wetlands have been used extensively for the removal of dissolved metals and metalloids. Although these contaminants are prevalent in mine drainage, they are also found in stormwater, landfill leachate and other sources (e.g., leachate or FDG washwater[citation needed] at coal-fired power plants), for which treatment wetlands have been constructed for mines,[48] and other applications.[49]
Mine water—Acid drainage removal
A seminal publication was a 1994 report from the US Bureau of Mines [50] described the design of wetlands for treatment of acid mine drainage from coal mines. This report replaced the existing trial-and-error process with a strong scientific approach. This legitimized this technology and was followed in treating other contaminated waters.
General application
See also: Reed bed
The three treatment set-ups mostly employed in combined treatment ponds
The three types, using reed beds (constructed wetlands but using principally reed plants), are used. All these systems are used commercially, usually together with septic tanks[51] as primary treatment, Imhoff tanks or screeners in order to separate the solids from the liquid effluent). Some designs however are being used to act as primary treatment as well.[52]Another way is the combination constructed wetland–composting toilet.
System types are:
Surface flow (SF) Constructed Wetland (or reed bed)
Subsurface Flow (SSF) Constructed Wetland (or reed bed)
Vertical Flow (VF) Constructed Wetland (or reed bed)
All three types are placed in a basin with a substrate. For most undertakings the bottom is lined with either a polymer geomembrane, concrete or clay (when there is appropriate clay type) in order to protect the water table and surrounding grounds. The substrate can be either gravel—generally limestone or pumice/volcanic rock, depending on local availability, sand or a mixture of various sizes of media (for vertical flow constructed wetlands).
Design characteristics—commercial systems
A commercial water-purifying pond, planted with Iris pseudacorus
Surface flow Constructed Wetlands: characterized by the horizontal flow of wastewater across the roots of the plants. They are being phased out due to the large land-area requirements to purify water—20 square metres (220 sq ft) per person—and the increased smell and poor purification in winter.[52]
Subsurface flow Constructed Wetlands: the flow of wastewater occurs between the roots of the plants and there is no water surfacing (kept below gravel). As a result the system is more efficient, doesn't attract mosquitoes, is less odorous and less sensitive to winter conditions. Also, less area is needed to purify water—5–10 square metres (54–110 sq ft). A downside to the system are the intakes, which can clog easily, although some larger sized gravel will often bypass this problem.[52][53] For large applications, they are often used in combination with vertical flow constructed wetlands. In warm climate, for organic loaded sewage, they require about 3.5 m2 / 150 L for black and grey water combined, with an average water level of 0.50 m. In cold climate they will require the double size (7 m2/150 L). For blackwater treatment only, they will require 2 m2 /50 L in warm weather.
Vertical flow Constructed Wetlands: these are similar to subsurface flow constructed wetlands but the flow of water is vertical instead of horizontal and the water goes through a mix of media (generally four different granulometries), it requires less space than SF but is dependent on an external energy source. Intake of oxygen into the water is better (thus bacteria activity increased), and pumping is pulsed to reduce obstructions within the intakes. The increased efficiency requires only 3 square metres (32 sq ft) of space per person.[52]
Plants and other organisms—commercial systems
See also: Organisms used in water purification
Mine water—Acid drainage removal
A seminal publication was a 1994 report from the US Bureau of Mines [50] described the design of wetlands for treatment of acid mine drainage from coal mines. This report replaced the existing trial-and-error process with a strong scientific approach. This legitimized this technology and was followed in treating other contaminated waters.
General application
See also: Reed bed
The three treatment set-ups mostly employed in combined treatment ponds
The three types, using reed beds (constructed wetlands but using principally reed plants), are used. All these systems are used commercially, usually together with septic tanks[51] as primary treatment, Imhoff tanks or screeners in order to separate the solids from the liquid effluent). Some designs however are being used to act as primary treatment as well.[52]Another way is the combination constructed wetland–composting toilet.
System types are:
Surface flow (SF) Constructed Wetland (or reed bed)
Subsurface Flow (SSF) Constructed Wetland (or reed bed)
Vertical Flow (VF) Constructed Wetland (or reed bed)
All three types are placed in a basin with a substrate. For most undertakings the bottom is lined with either a polymer geomembrane, concrete or clay (when there is appropriate clay type) in order to protect the water table and surrounding grounds. The substrate can be either gravel—generally limestone or pumice/volcanic rock, depending on local availability, sand or a mixture of various sizes of media (for vertical flow constructed wetlands).
Design characteristics—commercial systems
A commercial water-purifying pond, planted with Iris pseudacorus
Surface flow Constructed Wetlands: characterized by the horizontal flow of wastewater across the roots of the plants. They are being phased out due to the large land-area requirements to purify water—20 square metres (220 sq ft) per person—and the increased smell and poor purification in winter.[52]
Subsurface flow Constructed Wetlands: the flow of wastewater occurs between the roots of the plants and there is no water surfacing (kept below gravel). As a result the system is more efficient, doesn't attract mosquitoes, is less odorous and less sensitive to winter conditions. Also, less area is needed to purify water—5–10 square metres (54–110 sq ft). A downside to the system are the intakes, which can clog easily, although some larger sized gravel will often bypass this problem.[52][53] For large applications, they are often used in combination with vertical flow constructed wetlands. In warm climate, for organic loaded sewage, they require about 3.5 m2 / 150 L for black and grey water combined, with an average water level of 0.50 m. In cold climate they will require the double size (7 m2/150 L). For blackwater treatment only, they will require 2 m2 /50 L in warm weather.
Vertical flow Constructed Wetlands: these are similar to subsurface flow constructed wetlands but the flow of water is vertical instead of horizontal and the water goes through a mix of media (generally four different granulometries), it requires less space than SF but is dependent on an external energy source. Intake of oxygen into the water is better (thus bacteria activity increased), and pumping is pulsed to reduce obstructions within the intakes. The increased efficiency requires only 3 square metres (32 sq ft) of space per person.[52]
Plants and other organisms—commercial systems
See also: Organisms used in water purification
Plants
Although the majority of constructed wetland designers have long relied principally on Typhas and Phragmites, both species are extremely invasive, although effective. The field is currently evolving however towards greater biodiversity. Other designers (see http://www.wastewatergardens.net) use up to 200 different species, all climates included.
In North America, cattails (Typha latifolia) are common in constructed wetlands because of their widespread abundance, ability to grow at different water depths, ease of transport and transplantation, and broad tolerance of water composition (including pH, salinity, dissolved oxygen and contaminant concentrations). Elsewhere, Common Reed (Phragmites australis) are common (both in blackwater treatment but also in greywater treatment systems to purify wastewater). In self-purifying water reservoirs (used to purify rainwater) however, certain other plants are used as well. These reservoirs firstly need to be dimensioned to be filled with 1/4 of lavastone and water-purifying plants to purify a certain water quantity.[54]
They include a wide variety of plants, depending on the local climate and location. Plants are usually indigenous in that location for ecological reasons and optimum workings. Plants that supply oxygen and shade are also added in to complete the ecosystem.
The plants used (placed on an area 1/4 of the water mass) are divided in four separate water depth-zones:
0–20 cm: Yellow Iris (Iris pseudacorus), Simplestem Bur-reed (Sparganium erectum); may be placed here (temperate climates)
40–60 cm: Water Soldier (Stratiotes aloides), European Frogbit (Hydrocharis morsus-ranae); may be placed here (temperate climates)
60–120 cm: European White Waterlily (Nymphaea alba); may be placed here (temperate climates)
Below 120 cm: Eurasian Water-milfoil (Myriophyllum spicatum); may be placed here (temperate climates)
The plants are usually grown on coco peat.[55] At the time of implantation to water-purifying ponds, de-nutrified soil is used to prevent unwanted algaeand other organisms from taking over.
Fish and bacteria
A hybrid system using Flowforms in a treatment pond, in Norway.
Finally, locally grown bacteria and non-predatory fish are added to eliminate or reduce pests, such as mosquitos. The bacteria are usually grown locally by submerging straw to support bacteria arriving from the surroundings.
Three types of (non-predatory) fish are chosen to ensure that the fish can coexist:
surface;
middle-ground swimmers; and bottom
Examples of three types (for temperate climates) are:
Surface swimming fish: Common dace (Leuciscus leuciscus), Ide (Leuciscus idus), common rudd (Scardinius erythrophthalmus)
Middle-swimmers: Common roach (Rutilus rutilus)
Bottom-swimming fish: Tench (Tinca tinca)
Hybrid systems
Hybrid systems for example aerate the water after it exits the final reedbed using cascades such as Flowforms before holding the water in a shallow pond.[56] Also, primary treatments as septic tanks, and different types of pumps as grinder pumps may also be added.[57]
TYPES AND DESIGN CONSIDERATION
Types and design considerations
Subsurface flow constructed wetland - this wetland can be either with vertical flow (the effluent moves vertically, from the planted layer down through the substrate and out) or with horizontal flow (the effluent moves horizontally, parallel to the surface)
Surface flow constructed wetland (this wetland has horizontal flow)
Floating treatment wetland
The former types are placed in a basin with a substrate to provide a surface area upon which large amounts of waste degrading biofilms form, while the latter relies on a flooded treatment basin upon which aquatic plants are held in flotation till they develop a thick mat of roots and rhizomes upon which biofilms form. In most cases, the bottom is lined with either a polymer geomembrane, concrete or clay (when there is appropriate clay type) in order to protect the water table and surrounding grounds. The substrate can be either gravel—generally limestone or pumice/volcanic rock, depending on local availability, sand or a mixture of various sizes of media (for vertical flow constructed wetlands).
Subsurface flow
Schematic of a vertical subsurface flow constructed wetland: Effluent flows through pipes on the subsurface of the ground through the root zone to the ground.[15]
Schematic of the Horizontal Subsurface Flow Constructed Wetland: Effluent flows horizontally through the bed.[15]
Vertical flow type of constructed wetlands (subsurface flow)
In subsurface flow constructed wetlands the flow of wastewater occurs between the roots of the plants and there is no water surfacing (it is kept below gravel). As a result, the system is more efficient, does not attract mosquitoes, is less odorous and less sensitive to winter conditions. Also, less area is needed to purify water. A downside to the system are the intakes, which can clog or bioclog easily, although some larger sized gravel will often solve this problem.
Subsurface flow wetlands can be further classified as horizontal flow or vertical flow constructed wetlands. In the vertical flow constructed wetland, the effluent moves vertically from the planted layer down through the substrate and out (requiring air pumps to aerate the bed).[16] In the horizontal flow constructed wetland the effluent moves horizontally via gravity, parallel to the surface, with no surface water thus avoiding mosquito breeding. Vertical flow constructed wetlands are considered to be more efficient with less area required compared to horizontal flow constructed wetlands. However, they need to be interval-loaded and their design requires more know-how while horizontal flow constructed wetlands can receive wastewater continuously and are easier to build.[2]
Due to the increased efficiency a vertical flow subsurface constructed wetland requires only about 3 square metres (32 sq ft) of space per person equivalent, down to 1.5 square metres in hot climates.[2]
The "French System" combines primary and secondary treatment of raw wastewater. The effluent passes various filter beds whose grain size is getting progressively smaller (from gravel to sand).[2]
Applications[edit]
Subsurface flow wetlands can treat a variety of different wastewaters, such as household wastewater, agricultural, paper mill wastewater, mining runoff, tannery or meat processing wastes, storm water.[3]
The quality of the effluent is determined by the design and should be customized for the intended reuse application (like irrigation or toilet flushing) or the disposal method.
Design considerations
Depending on the type of constructed wetlands, the wastewater passes through a gravel and more rarely sand medium on which plants are rooted.[3] A gravel medium (generally limestone or volcanic rock lavastone) can be used as well (the use of lavastone will allow for a surface reduction of about 20% over limestone) is mainly deployed in horizontal flow systems though it does not work as efficiently as sand (but sand will clog more readily).[2]
Constructed subsurface flow wetlands are meant as secondary treatment systems which means that the effluent needs to first pass a primary treatment which effectively removes solids. Such a primary treatment can consist of sand and grit removal, grease trap, compost filter, septic tank, Imhoff tank, anaerobic baffled reactor or upflow anaerobic sludge blanket (UASB) reactor.[2] The following treatment is based on different biological and physical processes like filtration, adsorption or nitrification. Most important is the biological filtration through a biofilm of aerobic or facultative bacteria. Coarse sand in the filter bed provides a surfaces for microbial growth and supports the adsorption and filtration processes. For those microorganisms the oxygen supply needs to be sufficient.
Especially in warm and dry climates the effects of evapotranspiration and precipitation are significant. In cases of water loss, a vertical flow constructed wetland is preferable to a horizontal because of an unsaturated upper layer and a shorter retention time, although vertical flow systems are more dependent on an external energy source. Evapotranspiration (as is rainfall) is taken into account in designing a horizontal flow system.[3]
The effluent can have a yellowish or brownish colour if domestic wastewater or blackwater is treated. Treated greywater usually does not tend to have a colour. Concerning pathogen levels, treated greywater meets the standards of pathogen levels for safe discharge to surface water.[1] Treated domestic wastewater might need a tertiary treatment, depending on the intended reuse application.[2]
Plantings of reedbeds are popular in European constructed subsurface flow wetlands, although at least twenty other plant species are usable. Many fast growing timer plants can be used, as well for example as Musa spp., Juncus spp., cattails (Typha spp.) and sedges.
Operation and maintenance
Overloading peaks should not cause performance problems while continuous overloading lead to a loss of treatment capacity through too much suspended solids, sludge or fats.
Subsurface flow wetlands require the following maintenance tasks: regular checking of the pretreatment process, of pumps when they are used, of influent loads and distribution on the filter bed.[2]
Comparisons with other types
Subsurface wetlands are less hospitable to mosquitoes compared to surface flow wetlands, as there is no water exposed to the surface. Mosquitos can be a problem in surface flow constructed wetlands. Subsurface flow systems have the advantage of requiring less land area for water treatment than surface flow. However, surface flow wetlands can be more suitable for wildlife habitat.
For urban applications the area requirement of a subsurface flow constructed wetland might be a limiting factor compared to conventional municipal wastewater treatment plants. High rate aerobic treatment processes like activated sludge plants, trickling filters, rotating discs, submerged aerated filters or membrane bioreactor plants require less space. The advantage of subsurface flow constructed wetlands compared to those technologies is their operational robustness which is particularly important in developing countries. The fact that constructed wetlands do not produce secondary sludge (sewage sludge) is another advantage as there is no need for sewage sludge treatment.[2] However, primary sludge from primary settling tanks does get produced and needs to be removed and treated.
Costs
The costs of subsurface flow constructed wetlands mainly depend on the costs of sand with which the bed has to be filled.[3] Another factor is the cost of land.
Surface flow
Schematic of a free-water surface constructed wetland: It aims to replicate the naturally occurring processes, where particles settle, pathogens are destroyed, and organisms and plants utilize the nutrients.
Surface flow wetlands, also known as free water surface constructed wetlands, can be used for tertiary treatment or polishing of effluent from wastewater treatment plants. They are also suitable to treat stormwater drainage.
Surface flow constructed wetlands always have horizontal flow of wastewater across the roots of the plants, rather than vertical flow. They require a relatively large area to purify water compared to subsurface flow constructed wetlands and may have increased smell and lower performance in winter.
Surface flow wetlands have a similar appearance to ponds for wastewater treatment (such as "waste stabilization ponds") but are in the technical literature not classified as ponds.[17]
Pathogens are destroyed by natural decay, predation from higher organisms, sedimentation and UV irradiation since the water is exposed to direct sunlight.[1] The soil layer below the water is anaerobic but the roots of the plants release oxygen around them, this allows complex biological and chemical reactions.
Surface flow wetlands can be supported by a wide variety of soil types including bay mud and other silty clays.
Plants such as Water Hyacinth (Eichhornia crassipes) and Pontederia spp. are used worldwide (although Typha and Phragmites are highly invasive).
However, surface flow constructed wetlands may encourage mosquito breeding. They may also have high algae production that lowers the effluent quality and due to open water surface mosquitos and odours, it is more difficult to integrate them in an urban neighbourhood.
Hybrid systems
A combination of different types of constructed wetlands is possible to use the specific advantages of each system.[2]
Newly planted constructed wetland
Same constructed wetland, two years later
Others
Integrated constructed wetland
An integrated constructed wetland (ICW) is an unlined free surface flow constructed wetland with emergent vegetated areas and local soil material. Its objectives is not only to treat wastewater from farmyards and other wastewater sources, but also to integrate the wetland infrastructure into the landscape and enhancing its biological diversity.[18]
Integrated constructed wetland facilitates may be more robust treatment systems compared to other constructed wetlands.[19][20][18] This is due to the greater biological complexity and generally relatively larger land area use and associated longer hydraulic residence time of integrated constructed wetland compared to conventional constructed wetlands.[21]
Integreated constructed wetlands are used in Ireland, the UK and the United States since about 2007. Farm constructed wetlands, which are a subtype of integrated constructed wetlands, are promoted by the Scottish Environment Protection Agency and the Northern Ireland Environment Agency since 2008.[21]
Plants and other organisms
See also: Organisms used in water purification
Plants
.jpg)
Newly planted constructed wetland for blackwater treatment (Lima, Peru)
.jpg)
The large roots of this uprooted plant growing in a constructed wetlands indicate a healthy plant (Lima, Peru)
Typhas and Phragmites are the main species used in constructed wetland due to their effectiveness, even though they can be invasive outside their native range.
In North America, cattails (Typha latifolia) are common in constructed wetlands because of their widespread abundance, ability to grow at different water depths, ease of transport and transplantation, and broad tolerance of water composition (including pH, salinity, dissolved oxygen and contaminant concentrations). Elsewhere, Common Reed (Phragmites australis) are common (both in blackwater treatment but also in greywater treatment systems to purify wastewater).
Plants are usually indigenous in that location for ecological reasons and optimum workings.
Fish and bacteria
A hybrid system using Flowforms in a treatment pond, in Norway.
Locally grown bacteria and non-predatory fish can be added to surface flow constructed wetlands to eliminate or reduce pests, such as mosquitos. The bacteria are usually grown locally by submerging strawto support bacteria arriving from the surroundings.
Amphibians
Stormwater wetlands provide habitat for amphibians[22] but the pollutants they accumulate can affect the survival of larval stages[23], potentially making them function as ecological traps[24].
Costs
Since constructed wetlands are self-sustaining their lifetime costs are significantly lower than those of conventional treatment systems. Often their capital costs are also lower compared to conventional treatment systems.[25] They do take up significant space, and are therefore not preferred where real estate costs are high.
History
Subsurface flow constructed wetlands with sand filter bed have their origin in Europe and are now used all over the world. Subsurface flow constructed wetlands with a gravel bed are mainly found in North Africa, South Africa, Asia, Australia and New Zealand.[2]
Examples
Austria
The total number of constructed wetlands in Austria is 5,450 (in 2015).[26] Due to legal requirements (nitrification), only vertical flow constructed wetlands are implemented in Austria as they achieve better nitrification performance than horizontal flow constructed wetlands. Only about 100 of these constructed wetlands have a design size of 50 population equivalents or more. The remaining 5,350 treatment plants are smaller than that.[26]
United States of America
The Arcata Marsh in Arcata, California is a sewage treatment and wildlife protection marsh.
Australia
The Urrbrae Wetland in Australia was constructed for urban flood control and environmental education.
At the Ranger Uranium Mine, in Australia, ammonia is removed in "enhanced" natural wetlands (rather than fully engineered constructed wetlands), along with manganese, uranium and other metals
See also
Wetlands Construídos (a company in Brazil)
http://en.wikipedia.org/wiki/Constructed_wetlandSUMMARY
Are humans 'intelligent' enough to live in harmony with it's environment and Nature, like all wild animals?
Or is humanity dumber than animals, and willing to commit global suicide, much like lemmings rushing off a cliff to their certain doom?
Or is humanity dumber than animals, and willing to commit global suicide, much like lemmings rushing off a cliff to their certain doom?
End
Sustainable Solution For Red Tides, Toxic Algae Blooms That Kill Fish - Man Made Sewage Treatment Wetlands Marsh. Which Removes Excess Nitrogen, Phosphorus, Potassium (NPK), Ammonia, Heavy Metals From Grey Or Black Water
0 Yorumlar