Performance of inclined plates settler integrated with constructed wetland for high turbidity water treatment

A Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Masters in Hydrology and Water Resources Engineering of the Nelson Mandela African Institution of Science and TechnologyThe purpose of this study was to investigate and demonstrate a cost-effective treatment technology for high turbid water, commonly used for domestic purposes in rural areas of Tanzania where conventional water treatment techniques are not available. A study was conducted on the water quality status of five permanent earth dams within Monduli district during the wet and dry seasons, by analyzing physicochemical and microbial characteristics. The water characteristics of the five earth dams tested were significantly correlated (p < 0.05) and most of the tested parameters including turbidity and faecal coliform (FC) were above the Tanzania Bureau of Standards (TBS) drinking water standards. In this study, a pilot-scale inclined plates settler integrated with constructed wetland (IPS-CW system was tested on Nadosoito dam water with turbidities ranging from 186 to 4011 NTU. The IPS-CW system was meant to remove organic matter, nutrients and pathogens, with major focus on turbidity and FC removal, at the test flow rates of 20, 15, 10 and 5 L/min. The system removed substantial amount of contaminants, thereby achieving maximum removal efficiency of 95.9% and 94.3% for turbidity and FC respectively. Although using this combination of technologies in improving drinking water quality is uncommon, nitrate and biochemical oxygen demand met the TBS and World health Organization drinking water standards of ≤ 50 mg/l and ≤ 6 mg/L respectively. Due to low production cost and simplicity in operation, the system can be implemented in rural communities with high turbidity water sources however, further disinfection is required to ensure zero FC