MC4 -- On Site Application of Electrocoagulation Treatment of Rendering Wastewater
Document Type
Event
Abstract
Animal rendering produces wastewater high in fats and chemical oxygen demand (COD), the removal of which is necessary during treatment. Conventional rendering wastewater treatment includes the addition of polymer coagulants for COD removal which can be costly, because of either high coagulant doses or the addition of an acid to lower pH is often required to ensure adequate COD removal. An alternative, electrocoagulation-electroflotation (EC-EF), is an emerging wastewater treatment technology, where an electrode pair is submerged in wastewater while a constant current density is applied. This EC-EF cell utilizes an aluminum mesh anode to produce aluminum ions which act as a coagulant, and a stainless-steel mesh cathode, to produce hydrogen gas that floats fats to the surface of the cell. After the EC-EF process, treated wastewater then undergoes flocculation and sedimentation. Samples taken of raw influent and EC-EF effluent are tested for COD, aluminum concentration, and pH, while the samples taken after flocculation, 1 hour sedimentation, and 24 hours sedimentation are tested only for COD. Initial lab tests of rendering wastewater not pH adjusted have shown EC-EF provides over a 30 percent initial reduction in COD, with additional removal after flocculation and sedimentation have occurred, with total COD reduction reaching 50 percent. Initial tests for rendering wastewater pH treated to circumneutral showed slightly less COD removal than at natural pH. Final COD removal efficiencies have been comparable to those seen in conventional treatment, without additional pH treatment. This technology will be applied on site at rendering facility, using a larger EC-EF cell, to show viability in industrial wastewater treatment. If on site testing is successful, this treatment technique should be shown to be a suitable replacement for conventional treatment.
Keywords
Math, Computer Science, Informatics
MC4 -- On Site Application of Electrocoagulation Treatment of Rendering Wastewater
URC Greatroom
Animal rendering produces wastewater high in fats and chemical oxygen demand (COD), the removal of which is necessary during treatment. Conventional rendering wastewater treatment includes the addition of polymer coagulants for COD removal which can be costly, because of either high coagulant doses or the addition of an acid to lower pH is often required to ensure adequate COD removal. An alternative, electrocoagulation-electroflotation (EC-EF), is an emerging wastewater treatment technology, where an electrode pair is submerged in wastewater while a constant current density is applied. This EC-EF cell utilizes an aluminum mesh anode to produce aluminum ions which act as a coagulant, and a stainless-steel mesh cathode, to produce hydrogen gas that floats fats to the surface of the cell. After the EC-EF process, treated wastewater then undergoes flocculation and sedimentation. Samples taken of raw influent and EC-EF effluent are tested for COD, aluminum concentration, and pH, while the samples taken after flocculation, 1 hour sedimentation, and 24 hours sedimentation are tested only for COD. Initial lab tests of rendering wastewater not pH adjusted have shown EC-EF provides over a 30 percent initial reduction in COD, with additional removal after flocculation and sedimentation have occurred, with total COD reduction reaching 50 percent. Initial tests for rendering wastewater pH treated to circumneutral showed slightly less COD removal than at natural pH. Final COD removal efficiencies have been comparable to those seen in conventional treatment, without additional pH treatment. This technology will be applied on site at rendering facility, using a larger EC-EF cell, to show viability in industrial wastewater treatment. If on site testing is successful, this treatment technique should be shown to be a suitable replacement for conventional treatment.