Utilisation of Raw Marsh Clam Shell as Adsorbent for Phosphate Removal via Different Concentration of Aqueous Solution

ASM Sc. J., 20(2), 2025

Published on December 5, 2025

https://doi.org/10.32802/asmscj.2025.1774

Author: Noorul Hudai Abdullah, Chong Hou Yi, Tan Kai Lun, Lee Oon Teck, Nur Atikah Abdul Salim, Muhammad Abbas Ahmad Zaini, Wen-Pei Low, NSA Zainal

Abstract

Nutrient pollution is one of the most challenging environmental problems worldwide. Excess phosphate in water causes eutrophication, where algae bloom occurs and deteriorates water quality due to decreasing oxygen levels, affecting aquatic life. Marsh clam shell has potential as an adsorbent material due to its plentiful supply and good absorption capability towards phosphate. The aim of this study is to investigate phosphate removal by using raw marsh clam shell as the adsorbent in different concentrations of aqueous solution (5, 10, 15, 20, and 25 mg/L) in batch experiments. The mass of adsorbent was kept constant at 2 g and the volume of aqueous solution was fixed at 100 mL. Phosphate removal for the solution with 25 mg/L concentration was the highest, 5.8% compared to other concentrations. The experimental data obtained were compared to the theoretical data. The experimental data fitted well with the pseudo-second-order kinetic model (R2 = 1) and Freundlich isotherm model (R2 = 0.9982), suggesting that phosphate adsorption onto raw marsh clam shell is a chemical and multilayer sorption. In conclusion, the application of raw marsh clam shells for phosphate removal from aqueous solutions has potential as a low-cost and effective future wastewater treatment alternative for domestic and industrial wastewater treatment systems.

Keywords: adsorption, Freundlich isotherm, marsh clam shell, phosphate, pseudo-second-order kinetics