Establishment of material flow analysis (MFA) for heavy metals in a wastewater system

Abstract

This study is conducted based on the pressing environmental issue in Malaysia of heavy metals concentrations in wastewater systems. The wastewater system includes the Klang River and its tributaries; the Gombak River and Penchala river; ex-mining areas, and wastewater treatment plants. One of the major causes of heavy metal pollution in rivers is the illegal dumping of industrial waste directly into rivers without proper treatment. This study is done to determine the effectiveness of a treatment system in removing heavy metals within system boundary, under the assumption that the treatment plant operates at 95% efficiency; analysing the generation of heavy metal from sources of pollution to the treatment system; and comparing the effectiveness of heavy metal removal systems based on different scenarios accordingly to the needs of standard requirements of effluents discharge. STAN2.6 software is used in this study to establish the flow of the heavy metals from its origin to its discharge from the treatment plant. Heavy metal concentrations are manipulated under various conditions, including wet flow and dry flow season. Based on the levels of heavy metals, MFA is used to evaluate the concentration of treated heavy metals and the amount of heavy metals allowed to be discharged after treatment according to Standard A and Standard B. Based on this study, it was found that the amount of heavy metals in the river flow exceeds the allowable amount of heavy metal discharge both in upstream and downstream locations. Few assumptions were made in this study due to restricted data availability.