Using slow sand filter for organic matter and suspended solids removal as post-treatment unit for wastewater effluent

Certain applications of wastewater after treatment necessitate the implementation of a post-treatment system (PTS) to elevate effluent quality, especially in cases where human exposure, such as irrigation, is a possibility. Slow sand filters (SSF) have emerged as a pivotal technology in PTS; these systems offer the advantage of significantly enhanced effluent quality. This research endeavors to assess the efficiency of a supply pond by incorporating top-surface funnel units at its outlets. Additionally, it comprehensively evaluates the overall performance of a PTS that was designed to serve as tertiary treatment for secondary-treated effluent originating from the Rafah Wastewater Treatment Plant in the Gaza Strip, Palestine. The PTS design demonstrated substantial efficacy, including a 70% reduction in biochemical oxygen demand, a 60% reduction in chemical oxygen demand, and an impressive 79.5% reduction in fecal coliform levels. Furthermore, this unit eliminates 53% of total suspended solids (TSS). However, despite these achievements, the presence of residual biological pollutants presents challenges regarding the water's suitability for agricultural applications. Certain applications of wastewater after treatment necessitate the implementation of a post-treatment system (PTS) to elevate effluent quality, especially in cases where human exposure, such as irrigation, is a possibility.