Removal of humic acid from water by physico-chemical methods and advanced oxidation processes and coupled with cost analysis

Yalcin Gunes, Ozgun Gundag, Tuba Ozturk, Gul Kaykioglu, Deniz Izlen Cifci

Tekirdag Namik Kemal University, orlu Engineering Faculty, Department of Environmental Engineering, orlu 59860- Tekirdag, T rkiye

Abstract


In this study, various methods for humic acid (HA) removal from water, including physico-chemical methods (adsorption, coagulation-flocculation) and advanced oxidation processes (ozone oxidation, Fenton oxidation and photocatalytic oxidation), were investigated along with a comparative economic analysis. The results showed that adsorption using 2 g/L powdered activated carbon demonstrated promising results with a removal efficiency of 96% at pH 4. Coagulation-flocculation with FeCl3 (40 mg/L) and Al2(SO4)3 (40 mg/L) at pH 5 showed HA removal rates of 94% and 93%, respectively, with FeCl3 proving to be more efficient. Fenton oxidation resulted in a removal efficiency of 95% at pH 4, with 60 min of oxidation and optimal doses of 80 mg/L Fe2+ and 120 mg/L H2O2. Ozone oxidation achieved a lower removal efficiency of 81% at pH 10, and its high cost makes it less favorable. Photocatalytic oxidation with UV-A and UV-C light, combined with 300 mg/L TiO2 catalyst, exhibited the highest removal efficiency of 99% within 30 minutes. However, its high cost limits its practical application. Cost analysis revealed that physicochemical methods like adsorption and coagulation-flocculation are not only effective but also economical for HA removal. As a result, while advanced oxidation processes offer high removal efficiency, they come with significant costs. Physico-chemical methods remain viable options for HA removal, providing both efficiency and cost-effectiveness. However, careful consideration of disposal costs for waste materials generated during these processes is essential for a comprehensive cost analysis.

Keywords


adsorption; coagulation-flocculation; Fenton oxidation; humic acid; ozone oxidation; photocatalysis

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