Abstract

Boontida Uapipatanakul

DOI : http://dx.doi.org/10.13005/ojc/3404028

Natural resources are declining rapidly. Water scarcity is one of the biggest crises that the world faces. Even though there are many treatment methods, it still leaves a large carbon footprint. Hence, biological treatment is desired. However, there are many toxic compounds that contaminate wastewater, which inhibit biological treatment. Therefore, waste egg and shrimp shells were introduced as adsorbents to immobilize toxicity as a pre-treatment method. Egg and shrimp shells were tested for their surface charge with zeta potential. Then, Escherichia coli (E.coli) cells were exposed to the toxic compounds, copper sulfate and carbonyl phenol, for 15 minutes. Subsequently, E.coli cells were regrown on the agar plates to determine the recuperation rate of the colonies. It was found that eggshells decreased the toxicity of the tried concoction to E.coli, and enabled the colonies to recover by up to 62%. Moreover, it has proved that there is potential that the surface charge has an effect on the adsorption process. Eggshells, which have -21.85 zeta potential, adsorb copper sulfate, which is positively charged, better than carbonyl phenol, which is negatively charged; and vice versa for shrimp shells.

adsorption; toxicity immobilisation; waste materials; zeta potential.

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