Adsorption of chemical oxygen demand and ammoniacal nitrogen removal from leachate using seafood waste (green mussel shell) as low-cost adsorbent

The physical appearance of leachate when it emerges from a typical landfill site is a strongly odoured black, yellow or orange colored cloudy liquid which contains organic and inorganic pollutants which makes it unsatisfactory to be released in water bodies without any prior treatment. The goal of current study was to examine the effectiveness of waste green mussel shell (WGMS) for the removal of pollutants from stabilized leachate. Chemical oxygen demand (COD) and ammonium nitrogen (NH3-N) was investigated as the two major contaminants in leachate. In this study, adsorption method employed for the treatment of landfill leachate. Static batch experiment was carried out with 100 mL leachate sample with pH 7, contact time 120 min, dosage 4.0 g with 200 rpm shaking speed. The best removal was achieved at 2.0 g with the removal percentage of COD and N-NH3 were 58% and 48%, respectively. Langmuir isotherm adsorption model showed best fitted with coefficient of determination for COD with the value of R-2 = 0.9944 and NH3-N with the value of R-2 = 0.9918 respectively as compared to Freundlich model shows the value for COD with the value of R-2 = 0.9825 and NH3-N with the value of R-2 = 0.9508. Thus, it indicates adsorbent adsorption occurs monolayer adsorption on homogeneous surface. The WGMS provides a significantly lower cost medium for reduction of COD and NH3-N.