Technology

The Process
ElecTemistryTM and HydroZapTM are systems, which use electrochemical treatment to remove contaminants from aqueous streams (electrocoagulation). It can be used effectively on both influent and effluent streams. Electrochemical treatment is generally used on industrial waste streams to allow the reuse or discharge of an industrial waste stream. The process uses electricity rather than expensive, dangerous, and sometimes toxic chemicals to remove contaminants. Electrochemical treatment can be a pretreatment for other processes such as reverse osmosis, or a polish treatment for traditional treatment processes.


The Modules
The modules are constructed with either iron or aluminum materials.

Analysis has been done on a wide range of materials including lead, copper, nickel, zinc, and even titanium to find the materials that met all the criteria of inventor Bob Herbst.

Iron and aluminum both met the following requirements:

  • Sacrificial quality
  • Cost effectiveness
  • Conductivity
  • Non-toxic
  • Availability
  • Effectiveness of treatment on the widest variety of contaminants


What It Is
Electrocoagulation is the scientific discipline of utilizing electricity as the electromotive force to drive chemical reactions in a solution, suspension, or emulsion. A special form of direct current is introduced into the aqueous stream as it passes between predetermined electrodes in the electrocoagulation module. This energy from the electricity is the engine or driving force to shift the equilibrium of a reaction to less than equilibrium levels, thus providing a mechanism for removing dissolved, suspended or emulsified molecules, elements or ions to very minute levels in an aqueous stream.

What It Does
Electrochemical treatment can precipitate dissolved heavy metals by a combination oxidation reduction reaction that in many cases produces oxide crystals that are very stable. Hexavalent chromium is reduced to trivalent chromium and removed as a precipitate. Copper, Lead, Zinc, Nickel and other metals are oxidized into oxide crystal form and can sometimes be concentrated and removed from the sludge stream to be recycled. Some metals require an anion to be present to form a precipitate such as calcium, magnesium, molybdenum, and others. Many times this anion may already be present in the waste stream, but if not, it can generally be added very easily. These heavy metallic crystals can be a positive nucleus to attract the electron rich hydroxide floc and colloidal solids into a settle able precipitate. This precipitate can then be separated in a settling pond or in a clarifier after some of the heavy metals are classified and concentrated.



Electrocoagulation will break colloidal suspensions, which allows the precipitation and removal of suspended particles. The colloidal particle is flooded with electrons as the electricity is the flow of electrons. The excess of electrons causes the colloidal particles to attract to a sacrificed metallic cation, which comes from the electrodes as the electric current passes through the electrode in accordance with Faraday's Law. This metallic cation acts as a nucleus to attract the electron laden colloidal particles together into a floc precipitate. This generates a larger heavier floc, which can then be separated by a secondary separation process such as settling, clarification or centrifugation.

Electrocoagulation will break oil emulsions and release the tied up emulsified oil to float to the surface where it can be skimmed off with a vacuum and recovered if viable. Oil becomes emulsified as shearing action from pumps or chemicals cause an open or broken bond in the hydrocarbon chain, which then attaches itself with a weak bond to the water molecule. Even though this is a weak bond, it is a protected bond and consequently very difficult to break by conventional means. As the electricity passes through the water being treated, electrons and energy are available as well as hydrogen ions or protons from the electrolysis of the water itself, and oxygen or hydroxide ions as a chemical feed stock for reaction completion. These subsequent reactions cause the weak bond to be broken and the oils to return to being a complete molecule and the emulsion is broken. At this point the oil again becomes hydrophobic and generally floats to the surface due to differences in specific gravity.

ElecTemicalTM and HydroZapTM systems provide the electrochemical force to drive reactions to remove complex ions such as phosphates, silicates, carbonates, etc. Many times these anion radicals help to form insoluble precipitates such as calcium carbonate or calcium aluminum phosphate, which aid in cation removal. Sometimes the electrocoagulation force breaks down complex compound and organic halogens such as bromoform and dioxin. In all of these cases it is necessary to understand the chemical material balance of the reactions taking place, to make sure there is sufficient potential substance to balance with the available contaminants. The subsequent reaction will form insoluble precipitates or harmless by-products.

Electrocoagulation overwhelms bacteria by excess electrons causing the bacteria to be crushed by the pressure exerted by the attractive force of the electrons toward the nucleus of the bacteria cell. This crushing pressure causes bacteria and cysts to be eliminated from aqueous steams. Small molds and algae are removed in the same manner as colloidal particles.

What it Does Not Do
Electrocoagulation does not remove infinitely soluble materials such as sodium chloride or potassium compounds or sugars as it cannot form an insoluble precipitate of these compounds. It also does not remove miscible liquids such as alcohols or glycols or soluble gases such as ammonia or cyanide. It sometimes has difficulty with chelated compounds such as copper amide or gold cyanide, however it is possible to oxidize or air strip these compounds and then remove the metallic contaminants with electrocoagulation if viable. Electrocoagulation works best on aqueous streams of one per cent solids or less for normal treatment processes.

When enhanced with polymers, electrocoagulation can sometimes handle as much as 5% solids if the treated effluent is centrifuged. If higher solids are in the waste stream, then it may be necessary to loop back some of the treated water as a dilutant for the influent water in the waste stream. Additionally, contaminants that are resistant to Electrocoagulation treatment may be effectively treated by the inclusion of a carbon polish filter in the system configuration. Highly soluble elements such as sodium and potassium may be treated effectively with the addition of reverse osmosis

Wastewater Made Clear

Advanced Waste & Water Technology, Inc.
208 Route 109, Suite 101
Farmingdale, New York 11735

Tel: (917) 324-0166




Related Links

fracfocus.org
wateruseitwisely.com
dec.ny.gov
marcelluscoalition.org
jlcny.org

For your environmental analytical testing needs, please visit our strategic partner at eqservices.org.