Effect of reflector material and reflector shape on the treatment efficiency of Solar Enhanced Waste Stabilisation Pond (SEWSP)

Abstract

Large land area requirement is the primary factor militating against the use of waste stabilisation pond (WSP) in urban areas. Solar Enhanced Waste Stabilisation Pond (SEWSP) involves fitting reflectors to WSP to improve pollutant removal efficiency and reduce the land area requirement. This study compared the performances of a plane reflector and a parabolic reflector. The hypothesis is that parabolic reflector would utilise its unique optical and geometric properties to concentrate radiation better than plane reflectors. The comparative effect of different reflector material surfaces, namely: glass, printer’s plate, polished aluminium, ordinary aluminium and aluminium foil paper was also investigated. Analyses of samples from inlet (influent) and outlet (effluent) valves of a pilot-scale facultative SEWSP for suspended solids (SS), dissolved oxygen, 5-day biochemical oxygen demand (BOD₅) chemical oxygen demand (COD), total coliform (TC), and faecal coliform (FC) showed that the efficiency of the SEWSPs with respect to the mentioned parameters fluctuated with temperature, as influenced by the reflectors and material surface. The results concluded at 5% level of significance that parabolic reflector is more efficient and cheaper and that aluminium foil is the most suitable material in terms of durability and cost-effectiveness.