Adsorption of Zinc from Water by Coconut Coir Carbon

The research is to investigate the adsorption of zinc in wastewater by coconut coir
carbon. Industrial wastewater is increasingly contaminated by toxic metal ions which
cause serious enviromnental problem. There is a need to remove zinc from
water/wastewater to meet the standard for discharge of 5 milligrams per liter (mg/1)
Department of Enviromnent (2005). The objective of the study is to produce low cost
adsorbents from readily available material to remove zinc from water/wastewater.
The adsorbent is coconut coir carbon which is prepared through chemical activation
process by treating the coir with potassium hydroxide and subjected to physical
activation at 700.750 °C for 30 minutes in an oxygen.free oven. The optimum
conditions for removal of zinc by studying the effect of contact time, pH, and initial
concentration of zinc, and adsorbent particle size on the zinc adsorption. The
experiment conducted shows that the optimum contact time for batch studies was 3
hours and optimum pH was 6. Both optimum conditions were used to evaluate the
effect of adsorbent dose which shows the maximum adsorption at adsorbent
concentration of 1 giL. The adsorption was found to follow Langmuir isotherm with
Langmuir maximum capacity X., of 6.184. The adsorption follows pseudo-second
order kinetics with initial rate of 1.75 mg g-1 min"1
• Adsorption of zinc from water by
coconut coir carbon was proved to be effective as removal method, since coconut coir
is cheap and readily available, it has the potential to be used for removal of zinc from .
water.