Removal of Copper Using Groundwater Treatment Plant Sludge (GWTPS) Adsorbent in Continuous Flow Activated Sludge System

摘要

Copper is being widely used in a variety of textile, steel and dye industries. Wastewater containing copper and organic matters need to be treated prior to discharge to the environment. Current heavy metals removal methods involve high operation cost, energy and chemical consumption, and are sometimes unable to remove heavy metals to permissible levels. Sometimes copper is found in organically laden wastewater. The purpose of this study is to investigate the feasibility of using Groundwater Treatment Plant Sludge (GWTPS) as an adsorbent in removing copper in organic laden wastewater using a continuous flow activated sludge system. It is also to determine the capability of GWTPS in off-settling the toxicity effect of copper in a biological treatment process. The research was carried out by utilizing two identical laboratory-scales biological Reactors operated as extended activated sludge systems. One Reactor acting as control, received only copper and organic matter contaminated wastewater while, the other Reactor was also dosed with a fixed concentration of GWTPS in the aeration tank. Synthetic wastewater dosed with copper dosages of 0.5 mg/L, 1.0 mg/L, 2.0 mg/L, 5.0 mg/L, 10.0 mg/L and 15.0 mg/L of copper were used as influent to both Reactors. The results showed that GWTPS adsorbent improved the overall performance of biological treatment system in term of organic matter (TCOD & BOD) removal, copper removal and enhanced growth of microbes in the activated sludge system. With the inclusion of GWTPS as adsorbent and gradual acclimatization, microbes were able to withstand copper concentration up to 5.0 mg/L, as compared to 2.0 mg/L without GWTPS. Besides, it is also concluded that acclimatization is capable to improve microbes' tolerance toward copper toxicity from 1.0 mg/L to 2.0 mg/L in extended aeration activated sludge system.