Humic Acid Degradation by ZnO Photocatalyst

Abstract

Abstract. Humic acid (HA) is universally present in soils and natural water resources in a yellow-brown form. HA can react with chlorine during drinking water treatment and produce disinfection byproducts (DBPs), such as trihalomethanes (THMs) and haloacetic acids (HAAs), which are harmful for health. Therefore, HA has to be eliminated from water environment. The photocatalysis is an effective alternative solution for the degradation of HA in a water environment. This research aims to degrade HA from water environment. The rapid degradation of HA, using zinc oxide nanoparticles, irradiated by ultraviolet light (ZnO/UV), is investigated. The optimum conditions of pertinent factors, which include the light wavelength (UV-A and UV-C), and light intensity, HA concentration, ZnO dose, and contact time are investigated at neutral pH conditions, considered for drinking water treatment. HA degradation efficiency reached more than 80% after 60 min for both types of irradiation in optimum conditions of 0.3 g/L ZnO dose in 180 min of contact time. Comparisons for degradation efficiency under UV-A and UV-C irradiation indicate that UV-C has higher efficiency, up to 150 min of contact time. The reusability of catalyst is performed for three reuses and still revealed effective for beneficial commercial applications.

Biosynthesis of MnFe2O4@TiO2 magnetic nanocomposite using oleaster tree bark for efficient photocatalytic degradation of humic acid in aqueous solutions

“…The third reason is that at high humic acid values the photons received by the photocatalyst surface decrease because UV light is absorbed by the humic acid molecules and intermediate products (32). Results of the study of Babel et al showed that increasing the initial concentration of humic acid reduced its degradation e ciency (33).…”

Pengaruh Pengadukan pada Degradasi Asam Humat Menggunakan Reaktor Mobile Heksagonal

“…ZnO merupakan semikonduktor yang memiliki kelebihan sehingga dapat digunakan dalam proses degradasi asam humat dalam air. Kelebihan ZnO yaitu sifat fotokimia yang baik, sifat oksidasi yang tinggi serta murah dan non toksinitas [5]. ZnO memiliki band gap energi sebesar 3.37 eV [6].…”