Algal primary production in a dredged sludge disposal site

Abstract

In this report, the COD Mn amount produced in the stabilization pond of a dredged sludge disposal site was estimated and discussed. In the AGP (Algal Growth Potential) test of the effluent from the stabilization pond, Skeletonema costatum and Chlorella sp. grew to the cell density of 350,000 (cells)mL -1 (p-COD Mn . 2.1 mgL -1 ) and 240,000 (cells)mL -1 (p-COD Mn , 10.0 mgL -1 ), respectively. It was found also these values were increased by addition of the solution of materials from benthal mud and treated wastewater from Site 1 (aerated lagoon). The calculated amount of COD Mn produced in the stabilization pond was highest in spring, ranging from 6.8 to 172.7 ton(month) -1 . Most of the COD Mn amount produced was precipitated, degraded and taken up by Zooplankton in the stabilization pond, and 0.9 to 5.6 ton(month) -1 as p-COD Mn and 4.0 to 6.2 ton(month) -1 as sol.COD Mn were discharged.