Fate of Organic Pollutants in a Wastewater Land Treatment System Using Lagoon Impoundment and Spray Irrigation

摘要

Muskegon County Wastewater Management System (MCWMS) is one of the largest facilities of its kind treating on the average of 125 thousand cubic meters of wastewater by extended aeration, lagoon impoundment and spray irrigation. Over 70% of the influent originates from industrial sources including several organic chemical manufacturers. This study was undertaken to determine the fate of the organic compounds with in the treatment system. The water treated in this manner enters two storage lagoons (344 hectare each). Impoundment for approximately five months helps to further remove organics by further volatilization, sedimentation, biological breakdown and photodecomposition. The organic compounds surviving after this treatment are in most cases less than 1% of their influent concentrations. Spray irrigation of the lagoon impounded water, however, virtually removes all remaining organic matter. The draintiles which collect the soil percolated water show only sporadic low concentrations. In addition, after eight years of irrigation, the soils are almost free of organic compounds. The analysis of corn samples did not detect any uptake of man-made organics.