水文学: 現在の研究

Feasibility of a Filtration-Adsorption Grey Water Treatment System for Developing Countries

Abstract

Chidozie C Nnaji, Cordelia N Mama, Arinze Ekwueme and Terlumun Utsev

The performance and economic viability of a simple inexpensive grey water treatment system consisting of a
filtration unit and an adsorption unit was evaluated. At steady state, the overall performance of the combined system
was 85.68% BOD removal, 57.09% COD removal and 70.74% TSS removal. Most of the BOD removal (83.6%) was
achieved in the filtration unit, while most of the fecal coliform removal was achieved in the adsorption chamber. The
pH of the entire system remained stable (7.6 ± 0.29) throughout the experiment. The dissolved oxygen concentration
of the final effluent was 1.3 ± 0.28, indicating the need for aeration. Problems with carbon particle washout were
observed in the adsorption chamber. Generally, the final effluent was found to be suitable for a range of uses such as
toilet flushing, irrigation and fire protection. An economic analysis showed that 77.5% savings in water expenditure
can be achieved if a simple greywater treatment is installed for toilet flushing.