Applications & Wastewater EngineeringFats Oils and Grease (Peko Chicken, shrimp, etc.), Bacteria, Heavy Metals (BLM and Coca-Cola, Gulf Chemical molybdenum, Selenium, etc.), Organic Compounds, Inorganic Solids, Oil and Gas Production Compounds (Complete Production, Rush Overland, Elliot Oil and Gas, Endeavor O&G), Graywater (MOD, Butlers and Bethesda Laundry), Iron, Nitrogen, Phosphorous, Leachate, TSS and Sludge Dewatering (PWCSA and Tons per Hour), Marine Wastes (TC Curl oily wastewater), Cooling Water, (Lyondell Bassell removal of carbonates and other cations and anions from water = softening), Petroleum Wastes (DAF sludge, Crude Oil, TC Curl oily wastewater). Contact us for more information on wastewater engineering.
Typically, both domestic sewage and industrial wastewater contain certain amounts of organic contaminants. The application of direct current results in the dissociation of water and other molecules which creates an environment for simultaneous oxidation and reduction. Because organic compounds contain ionic or covalent bonds, the voltage potential causes the bonds to break thereby producing smaller, less troublesome molecules and often merely carbon dioxide and water.
Org - e- → Oxidation products + CO2↑ + H2O
The reduction of the organic compounds in domestic sewage, as measured by BOD, followed a first order straight line reduction that was directly related to the amount of power applied.
When bacteria break down organic compounds they strip dissolved oxygen out the of water causing polluted conditions and even fish kills. Inorganic solids, on the other hand, pollute water by blocking out sunlight, silting up the stream beds and covering the benthic organisms. The application of direct current electrons results in neutralization of the negative surface charges on the inorganic solids particles causing destabilization of the colloidal suspensions and the immediate separation and settling from the water.
EC LLC successfully removed: silt from stormwater; cement dust from water; dirt from laundry wastewater, carbon black from acetylene sludge and driller mud from lagoon water.
EC LLC performed two definitive pilot test programs with the objective of removing dissolved iron. The first was for the U.S. Bureau of Land Management at the Gold King Mine audit in Silverton Colorado. The second was for Milligan Brand in Chama, New Mexico. In both cases, the pH of the groundwater was 5.0 which resulted in dissolving iron from the rock strata. In both instances, the raw water iron concentration was 20.0 parts per million. And in both cases, the application of electrical current resulted in the oxidation and then precipitation resulting in an effluent iron concentration of 0.1 parts per million.
Gold King Mine – Silverton Colorado
Domestic sewage and numerous types of industrial are contaminated with nitrogen in a variety of forms. Ammonia is oxidized to nitrate through the aerobic process of nitrification and nitrate can be further reduced to nitrogen gas through the process of denitrification. The EPA defines the limits of technology for biological denitrification as 3.0 parts per million.
2 NO3- + 10 e- + 10H+ → 2 OH- + N2↑ + 4 H2O
Our research has demonstrated a 99% removal of both ammonia and nitrate and a variety of applications. Tests on secondary clarifier effluent showed a reduction of nitrate from between 10 – 20 parts per million to between 0.1 – 0.2 parts per million using the EC technology. On Smithfield, hog lagoon wastewater ammonia was reduced from 2,300 parts per million to 20 parts per million. And on Motiva refinery wastewater ammonia was reduced from 2,300 parts per million to 20 parts per million.
Phosphorous is another problem nutrient frequently found in domestic sewage and industrial wastewater. Electrochemical testing for the removal of phosphorous was performed at several municipal wastewater treatment plants and at numerous industrial facilities including Coca Cola’s Atlanta Base Beverage Plant.
Phosphorous commonly occurs in wastewater in the form of either orthophosphate (PO43-) or phosphoric acid (H3PO4). Phosphorous was efficiently and almost completely removed by electrochemical treatment through the release of iron in either the ferric (+3) or ferrous (+2) forms which then combined with the phosphate ions to form a precipitate. The oxidation reaction followed by the precipitation of phosphorous was observed as followed:
Fe3+ + PO43- → FePO4↓
The kill of bacteria was never a priority pollutant for the treatment using EC. However, in every pilot test for every wastewater, it was observed that in addition to all other electrochemical reactions for the treatment and removal of other contaminants, EC simultaneously achieved full and complete kill of coliform bacteria.
The exact means by which the coliform bacteria are killed is not yet fully understood. However, it has been suggested that either the flow of electrons serves to disrupt the cell walls of the bacteria or the excess hydroxyl radicals are responsible for the bacterial kill or bacteria attenuation is caused by another electrochemical mechanism altogether. At this time there is insufficient data and information available upon which to draw a sound conclusion as to the exact means by which bacteria kill is achieved other than to say the 100% kill was achieved in every application.
Waste Activated Sludge Conditioning
Arguably the largest waste disposal problem in the United States is the disposal of activated sludge from wastewater treatment plants.
The use of our electrochemical technology to condition and concentrate waste activated sludge has been very positive. Test results indicate the bacterial cells are lysed releasing bound water while at the same time the cell surface charges are neutralized. This has resulted in a rapidly settling sludge that when pressed dewaters to twice the density in half the time without the use of polymers or other chemicals as compared to conventionally conditioned sludge.
Oil and Gas Production
Our electrochemical technology has been used extensively to treat wastewater in the oil and gas production industry. Whether it is driller mud, flow-back water or produced frack water, EC has been very effective in removing petroleum oils and solids. Tests of raw and treated wastewater from an Endeavor site in Midland, TX are shown to the right.
EC has shown to be effective for removing heavy oil from water and water from crude oil. The EC treatment pictures shown below are: bilge water at the Global Environmental Marine Services site in Corpus Christi, TX; oily water at the Elliott Oil and Gas site in Alvin, TX; separation of water from crude oil; and separation of oily tank cleaning DAF sludge into top oil, bottom sludge and water in the middle.
Fats, Oils and Grease
Like the removal of petroleum oils, our electrochemical technology is highly effective in the separation of food grade fats, oils, and grease. Whether it is animal slaughtering, further processing or cooking and packaging in the poultry, beef, pork or seafood industries, EC can be used in lieu of chemical addition ahead of a dissolved air flotation clarifier. EC eliminates the use of chemicals to separate fats, oils, and grease and resulting in a cleaner and denser rendered byproduct.
In two definitive studies, EC was used effectively to treat greywater to reuse quality. In an international search for new water treatment technologies, the U. K. Ministry of Defense selected EC as its preferred technology of choice for treatment of greywater for reuse, raw water for drinking and black water for disposal at its Forward Operating Bases (FOBs). In trials on domestic laundry, sink and shower water EC produced treated drinking water that met NATO STANAG standards for emergency field conditions and was palatable for drinking at the Climate Day demonstration. In fact, BAE Systems which monitored the presentation concluded that “EC is producing drinking water at a cost of 1/1000 the present cost of FOB water.”
In the Dubai Butler’s Laundry trials, EC effectively removed dirt and detergents to levels for reuse in the laundry thereby reducing the cost of purchased water and the cost of discharged wastewater to the municipality achieving a return on investment of fewer than two years.
Our electrochemical technology has proven to be effective in removing heavy metals from water. In the trials at the Bureau of Land Management site in Silverton, CO, in addition to removing iron, EC removed lead, chromium, and copper to non-detect. At the Coca-Cola Base Beverage Plant, Copper was removed from the nanofiltration reject water. And at Gulf Chemical in Corpus Christi, TX molybdenum was removed from process water. EC has also proven effective for the removal of selenium and arsenic.