Treatment of the spin cycle effluent using electrocoagulation and granular activated carbon

Given the rising demand for freshwater and its limited availability, treating and reusing household wastewater is becoming increasingly crucial. One way to accomplish this is to treat and reuse spin cycle effluent from washing machines. The spin cycle, being the last washing cycle, yields comparatively cleaner effluent, necessitating less intensive treatment, rendering it an attractive target for treatment and reuse. This study presents the first instance of characterizing and treating this effluent. The average values for spin cycle effluent for chemical oxygen demand, biochemical oxygen demand, pH, conductivity, turbidity, total nitrogen, and orthophosphate were found to be 241.8 ± 88.4 ppm, 36.9 ± 14.3 ppm, 7.2 ± 0.9, 223.4 ± 46.7 μS/cm, 85.9 ± 20.1 NTU, 7.2 ± 3.1 ppm, and 4.6 ± 1.7 ppm, respectively. The treatment study was conducted at a 2-L scale using aluminum electrodes in a bipolar setup and utilized three liquid and three solid detergents. The treatment process consisted of sequential utilization of electrocoagulation flocculation and granular activated carbon which resulted in excellent treatment, with a 92.7 ± 3.6% reduction in chemical oxygen demand, an 87.2 ± 9.7% reduction in total nitrogen, a 91.4 ± 2.9% reduction in orthophosphate, and a 93.3 ± 4.7% reduction in turbidity. Utilizing the reuse potential of the spin cycle effluent with this process will allow households to actively contribute to sustainable water management practices.