Removal of Copper Using Microwave Incinerated Rice Husk Ash (MIRHA) In Continuous Flow Activated Sludge System

Copper is being widely used in a variety of textile, steel and dyes industries. Wastewater
contains copper and organic matters need to be treated prior to discharge to the
environment, else it could pose adverse health effects to human. Current heavy metals
removal methods, such as adsorption by activated carbon, ion exchange, reverse
osmosis, chemical precipitation and nanofiltration, are expensive, unable to completely
remove heavy metals and involve high energy and chemical consumption. The purpose
of this research is to propose the removal of copper and organic matters using biological
treatment system, dosed with Microwave Incinerated Rice husk Ash (MIRRA)
adsorbent. The objectives are to study if MIRRA is capable to delay the toxicity effect
of copper and the feasibility of using MIRRA as low cost copper adsorbent in activated
sludge system. The research is carried out by conducting experiments using 2 scaled
down biological reactor. Medium strength wastewater dosed with copper at dosage of
0.5 mg/L, 1.0 mg/L, 2.0 mg!L, 5.0 mg/L and 10.0 mg/L is used as influent. The reactor
is run in Extended Aeration Activated Sludge mode. The result shows that MIRRA
adsorbent has improved the overall performance of biological treatment system in term
of organic matters (TCOD & BOD) removal, copper removal and improved the growth
of microbes in the activated sludge system. With MIRRA adsorbent and gradual
acclimatization, microbes are capable to withstand copper concentration up to 5.0 mg/L,
as compared to 2.0 mg/L without MIRRA. 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. In short, Extended
Aeration Activated Sludge system dosed with MIRRA adsorbent is a new approach
toward removal of copper and organic matters in wastewater that contains copper
concentration up to 5. 0 mg/L.