The study of adsorption isotherm by using oyster shell powder adsorbs phosphorus

Abstract

Oyster is a common marine-cultural product at the southwest coast of Taiwan; but the by-product, oyster shell, often caused serious waste problem. If oyster shell could be used at on-site treatment as a medium material to adsorb phosphorus in wastewater, it might reduce not only the amount of wasted oyster shell, but also both the concentration of phosphorus and eutrophication problem This study is aim to use three different particle sizes of oyster shell powder between 0.42~0.84 mm under the experimental design of Langmuir Isotherm to obtain the maximum capacity of oyster shell of absorbing phosphorus, and compare the results with other adsorbents. Through these studies, this research might establish phosphorus adsorption capacity and related parameters of oyster shell while applying oyster shell on removing phosphorus in the future. The results showed that adsorption of phosphorus by using oyster shell were similar with the assumptions of Langmuir Isotherm: the maximum adsorption capacity of three particle sizes of oyster shell powder 0.42 mm, 0.59 mm and 0.84 mm were 200 mg/kg, 166.67 mg/kg, and 125 mg/kg. The maximum adsorption capacity increased with the decreasing of particle sizes. Compared with different types of soil and materials, the phosphorus adsorption ability of oyster shell was similar to them.