关键词: 溶解性有机物, 蒙脱土, 腐殖化, 吸附

Abstract: Organic compounds in the organic wastewater, generated by the natural product processing industries such as leather making and food fermentation, usually polymerize to form refractory dissolved organic compounds (DOM). In order to study the polymerization process and the influence of clay ore on their adsorption and stability, common organic compounds in wastewater were selected to simulate the wastewater for the polymerization reaction, and montmorillonite (MMT) was used for the adsorption research. The fluorescence spectra of the supernatant showed that the peak of fluorescence (E_x/E_m 250/310 nm) appeared at 0 d, and two groups of fluorescence peaks appeared in the fulvic acid-like (E_x/E_m 240/500) and humic acid-like (E_x/E_m 400/500 nm) regions at 5 d after the humification reaction. Humic acid HAL1 obtained in this work had the same characteristic peaks 1 and 2 compared to commercial HA. These two samples had the similar FTIR characteristics, and the generated HAL1 exhibited the same C-O tensile vibration as the saccharide group of the humic acid extracted from the natural black soil. After adding MMT, the TOC was reduced by about 30%. After the adsorption, the relative molecular weight of the residual molecules in the supernatant (M_n) was decreased from 660 000 to 75 000. With the increase of MMT addition, the fluorescence intensities in the fulvic acid-like and humic acid-like regions decreased. When MMT was used to re-adsorb the DOM in the supernatant after the polymerization reaction was stable, the TOC still decreased. It adsorbed 16.2 mg/g TOC in the small molecule solution and 5.25 mg/g TOC in the large molecule solution. The dry-wet alternation results showed that TOC was further increased by 11.32 mg/g.

Key words: dissolved organic matter, montmorillonite, humification, adsorption