Integrated Wastewater Treatment for a GRES

Abstract

An integrated approach is presented on wastewater treatment for power plants and the disposal of carbonate sludge—the waste forming at the make-up water pretreatment stage at power facilities. Usually, carbonate sludge accumulates on sludge waste sites located on the territory of power plants, which leads to an adverse impact on the environment. In addition to solid waste, the station also produces a large quantity of wastewater, which must be cleaned before being discharged into a waterbody. Concentrated wastewater is traditionally subjected to local treatment, which is associated with economic costs, while domestic and storm sewage is treated at general production wastewater treatment plants. The article proposes a wastewater biosorption technology at the Karmanovskaya GRES in which conditioned carbonate sludge is used as a sorption material. The sorption ability of carbonate sludge is confirmed by sorption isotherms of petroleum products and ammonium nitrogen. The kinetic curves obtained as a result of research confirm that biosorption wastewater treatment with carbonate sludge has a higher efficiency than conventional biological treatment. With the introduction of carbonate sludge into the aerotank for biosorption, the efficiency of wastewater treatment at the Karmanovskaya GRES increases significantly in terms of 5-day BOD, phosphate ion, chemical oxygen consumption (COD), ammonium nitrogen, and petroleum products. The use of carbonate sludge as a sorption material will improve the quality of treatment of all types of wastewater without their local treatment, which is equivalent to the wastewater’s final biofiltration. When implementing the technology of biosorption cleaning with water treatment sludge, the prevented environmental damage to the Karmanovsky reservoir will amount to 1 463 000 rubles per year in the event of oil- and salt-containing wastewater discharge from the GRES into the inlet chamber. The economic calculation of the presented technology is performed: the payback period will be 3 years and 10 months and the economic effect will be 563 000 rubles per year.