High increase in biodegradability of coking wastewater enhanced by Mn ore tailings in Fenton/O3 combined processes

Abstract

Coking wastewater contains high concentration of organic pollutants and seriously endangers the natural ecological balance and human health. This study proposes a novel pre-treatment method that can significantly improve removal efficiency of organic pollutants in coking wastewater by the concept of "treating waste with waste." Three two-step advanced oxidation processes were proposed by combining Fenton, ozonation with manganese tailings: (i) O 3 /Mn tailings + H 2 O 2 , (ii) O 3 /Mn tailings + Fenton and (iii) Fenton + O 3 /Mn tailings. Results show that (1) Fenton + O 3 /Mn tailings presented the best removal efficiency in the three combined processes. The reaction process was carried out by first performing Fenton reaction on the wastewater for 65 min, and then, the reaction wastewater was subjected to ozone and manganese tailings mixed reaction for 30 min, and the chemical oxygen demand (COD) and chromaticity were reduced by 61.0% and 96.1%, respectively. (2) After pre-treated with Fenton, the biodegradability of the wastewater can be significantly increased. When Fenton + O 3 /Mn ore tailings were used to pre-treat the raw water, the biodegradability (BOD 5 /COD) of the wastewater was increased to 0.54. It is proved that the combined process Fenton + O 3 /Mn ore tailings has better performance than the ordinary single advanced oxidation process. Compared with the existing methods, the addition of manganese tailings containing manganese oxides as catalytic free radicals can significantly improve the treatment activity of advanced oxidation process (AOPS).

Study and Application Status of Ultrasound in Organic Wastewater Treatment

“…There are multiple transition metal elements that can initiate the Fenton-like catalytic process, including Fe, Cu, Mn, and Pb [63,64], while Fe-based catalysts and Cubased catalysts are common ones. Fe-based Fenton-like catalysts consist of synthetic catalysts such as MnFe 2 O 4 /biochar, Fe-Mo/rGo [15], Fe/Cu@γ-Al 2 O 3 [16], and Fe/Acidmontmorillonite [65], iron ores, solid waste such as coal fly ash, slag, and gangue [6,[66][67][68][69], and zero-valent iron.…”

Ultra-efficient catalytic degradation of malachite green dye wastewater by KMnO4-modified biochar (Mn/SRBC)

“…25,26 At present, there are many studies on the degradation of organic contaminants by Mn/ H 2 O 2 systems. [27][28][29] However, there are few reports on the use of Mn and biochar composites as carbon-based catalysts.…”