Treatment of agricultural drainage water via lagoon/reverse osmosis system

Abstract

Treatment and reuse of agricultural drainage water (ADW) is complicated by the presence of soluble organic and inorganic pollutants in addition to hazardous chemicals. Large-scale desalination systems for agricultural drainage water require the development of affordable pretreatment for removal of soluble organic matters, which include residuals of agrochemicals and industrial pollutants. Current reports pertinent to the assessment of the typical characteristics of agricultural drainage water indicate that chemical oxygen demand (COD) concentration ranges from 50–250 mg/l. This paper presents process design features of an integrated scheme for the treatment of agricultural drainage water for reuse in non-agricultural purposes. The system essentially comprises aerated lagoon and two-stage reverse osmosis (RO) or electrodialysis for a plant capacity of 30,000 m 3/d. Results reveal the preliminary technical and economic feasibility of the proposed treatment/desalination system. The capital, operating and unit costs have been estimated. Recommendations for management of brine have been developed.