Discharge quality of bathroom greywater effects on soil and treatment by solar water distillation

Abstract

Direct discharge of bathroom greywater (BGW) with high content of chemical derivatives from soap and detergent products may alter the receiving environment. Therefore, this research was undertaken to study the quality and effects of BGW and treat the BGW by solar water distillation (SWD). Three samples of BGW were taken at the study area and designated as House A, House B, and House C. Testing of the soil was conducted prior to the irrigation using greywater to specify the soil characteristics. Towards the end of this study, chemical properties of the soil (pH), electrical conductivity (EC), cation exchange capacity (CEC), exchangeable sodium percentage (ESP) and sodium adsorption ratio (SAR) of the soil were determined. SWD treatment was tested for pH, biochemical Oxygen demand (BOD), chemical Oxygen demand (COD) and total Suspended Solid (TSS) of the BGW. The pH of the soil before irrigation was 3.22 ± 0.02 and increased to 4.06 ± 0.12, 4.32 ± 0.09, and 4.67 ± 0.05 after irrigation with BGW from House A, B, and C respectively. The highest EC (756 ± 5.68 µs/cm) was found in the BGW from House A, indicating the presence of high range of salt content. For saturated hydraulic conductivity; tap water recorded the highest value of 51.88 cm/h, followed by 24.24 cm/h, 31.12 cm/h, and 45.01 cm/h for irrigation with BGW from House A, B, and C respectively. For CEC, ESP, and SAR, it was found that the BGW from House A recorded the highest values compared to others, with values of 0.835 meq/100gm, 36.41%, and 10.73 respectively. Treatment of BGW with SWD shows the highest removal percentage BOD is 60%, COD is 72.2%, TSS is 64.7%. Hence, the use of SWD has a good potential to enhance the quality of the BGW before directly discharged to the water bodies.