Bioremediation of heavy metals from the aqueous environment using Artocarpus heterophyllus (jackfruit) seed as a novel biosorbent

Abstract

Biosorption is an environment-friendly and economic technique to remediate heavy metals from aqueous systems. In the present study, Artocarpus heterophyllus seed powder was used as a biosorbent material to remove different heavy metals. The batch adsorption studies confirmed the higher removal percentage of the Artocarpus heterophyllus (jackfruit) seed powder for arsenic (As⁵⁺), cadmium (Cd²⁺), and chromium (Cr⁶⁺) while lower efficiency was observed for other heavy metals like copper (Cu²⁺), zinc (Zn²⁺) and nickel (Ni²⁺). Optimization of different process parameters was carried out and the optimum conditions were: adsorbent weight of 0.5 g for the initial concentration of heavy metals as 40 μg/L, 30 mg/L, and 30 mg/L; contact time of 10 h, 8 h, and 6 h; process temperature from 25 to 30 °C; pH of 7, 7.5, and 7.5 for As⁵⁺, Cd²⁺, and Cr⁶⁺ respectively. The SEM-EDX, FTIR, and XRD studies before and after adsorption of heavy metals resulted in affirmative observations. The equilibrium data of the study was well fitted for Langmuir isotherm for As⁵⁺, Cd²⁺, and Cr⁶⁺, Freundlich for As⁵⁺and Cr⁶⁺, Dubinin-Radushkevich for Cd²⁺and Cr⁶⁺. The kinetic and thermodynamic study confirmed that the adsorption of all three heavy metals was following the pseudo-second-order kinetics with the endothermic and spontaneous process respectively. The cost analysis of the process confirmed that the whole process was cost-effective compared to other processes. Hence the Artocarpus heterophyllus seed powder was verified for its high heavy metal remediation efficiency from aqueous environments along with the added advantages of being eco-friendly and economic compared to other alternatives.

Keywords: Artocarpus heterophyllus (Jackfruit); Biosorption; Heavy metals; Isotherms; Optimization; Thermodynamics.