This paper conducts an experimental determination and assessment of the performance of greywater purification systems with varied filter media and observes their hydraulic behaviour in controlled conditions. Six laboratory-scale single-media and multi-layer column filtration experiments were conducted. Experiments on sand, gravel, activated carbon, biochar, zeolite, and ceramic media were conducted at the laboratory scale to determine the ability to eliminate physical, chemical and biological contaminants. Findings demonstrated turbidity removal efficiencies of 55 to 92 percent with activated carbon and biochar recording the best removal efficiencies. Multi-layer filter setups had a TSS removal rate of more than 80 percent with a reduction of 48 percent and 40 percent of BOD and COD, respectively. Hydraulic performance study revealed that the flow rates were stable ranging 0.8 to 1.5 L/min and the retention times of 20 to 35 minutes were identified as the optimum retention times to achieve efficient treatment. A monitoring system was also incorporated using IoT to monitor real-time flow and water quality parameters so that automated alerts could be taken, and maintenance was decreased by about 30%. The research assists in the construction of economical greywater treatment plant that can be used in the small-scale domestic and urban non-potable water consumption as irrigation and toilet flushing.
V et al. (2026) studied this question.