Service

The acclimation step involves subjecting the biological treatment system, activated sludge, for instance, to gradually increasing levels of the toxic substances in the full strength wastewater, until full-strength wastewater is being treated. One way to accomplish acclimation is to develop the activated sludge system using domestic wastewater until it is fully functional as a wastewater treatment system. Then, the pretreated industrial wastewater is added to the domestic wastewater starting with a mix of about 10% pretreated industrial wastewater and 90% domestic wastewater. When it has been established that the treatment system is working well on the 10%/90% mixture, the proportion of pretreated industrial wastewater is increased, and so on, until the treatment system is receiving and operating well on full-strength pretreated wastewater. What happens during the acclimation procedure is that the microorganisms develop the capability to produce enzymes that can metabolize the toxic materials in the pretreated industrial wastewater and that can grow and flourish in the activated sludge (or other biological treatment medium). Those that cannot gradually die off are replaced over time. The result is an “acclimated” biological treatment system that is able to successfully treat the pretreated industrial wastewater.

An acclimated biological treatment system consisting of three extended aeration basins in series has been developed. Phenols are removed in the first basin, oxidation of both ammonia and cyanide takes place in the second basin, and the third basin (nonaerated) is used to remove nitrogen via the denitrification process. It is necessary to maintain favorable concentrations of other nutrients, such as phosphorus, in each of the biological treatment basins.

Chemical-physical treatment systems have been used with some success. One version of chemical-physical treatment has been to use chemical oxidation to destroy organics, ammonia, and cyanide and then to use activated carbon to remove unreacted substances as well as partially treated substances. Oxidation is accomplished by adding chlorine to the pretreated wastes in an aeration basin. Oxygen from air and chlorine are the oxidizing agents. Spent activated carbon can then be recovered (partially) by the process of heating (incinerating).