Oxidation of waste water from peanut factories in Siirt region and optimization with answer surface method

During pistachio processing, 2-6 m3 of wastewater is generated per ton of processed pistachio in pistachio factories. Pistachio processing wastewater contains hazardous organic compounds that may cause environmental problems. When these wastewaters are directly release to the sewage system, due to their high chemical oxygen demand (COD), total organic carbon (TOC) and total phenol (TP), they put a heavy load on the urban wastewater treatment plant and reduce the efficiency of the treatment plant and prevent the discharge standards from being met. In this study, the subcritical water oxidation (SWO) of Siirt pistachio processing wastewater was investigated and optimum conditions were determined by examining experimental parameters such as temperature, H2O2 concentration and treatment time using response surface methodology. The highest COD, color and TP removal yields were obtained as 50.4%, 92.80%, and 99.7%, respectively. In addition, nitrite, nitrate, total phosphate, total nitrogen and suspended solids analyses of raw pistachio factory wastewater samples and SWO-treated samples were performed.