PAPERmaking! FROM THE PUBLISHERS OF PAPER TECHNOLOGY Volume 6, Number 2, 2019
Catalytic ozonation treatment of papermaking wastewater by Ag-doped NiFe2O4: Performance and mechanism, Junyu Zhao, Jiashun Cao, Yujie Zhao, Teng Zhang, Di Zheng & ChaoLi, Journal of Environmental Sciences , 97, Nov. 2020, https://doi.org/10.1016/j.jes.2020.04.014. The catalytic ozonation treatment of secondary biochemical effluent for papermaking wastewater by Ag-doped nickel ferrite was investigated. Ag-doped catalysts prepared by sol-gel method were characterized, illustrating that Ag entirely entered the crystalline of NiFe2O4 and changed the surface properties. The addition of catalyst enhanced the removal efficiency of chemical oxygen demand and total organic carbon. The results of gas chromatography-mass spectrometer, ultraviolet light absorbance at 254 nm and three-dimensional fluorescence excitation- emission matrix suggested that aromatic compounds were efficiently degraded and toxic substances, such as dibutyl phthalate. In addition, the radical scavenging experiments confirmed the hydroxyl radicals acted as the main reactive oxygen species and the surface properties of catalysts played an important role in the reaction. Overall, this work validated potential applications of Ag-doped NiFe2O4 catalyzed ozonation process of biologically recalcitrant wastewater. Feasibility and safety of papermaking wastewater in using as ecological water supplement after advanced treatment by fluidized-bed Fenton coupled with large- scale constructed wetland, Liqun Xing, Ming Kong, Xianchuan Xie, Jie Sun, Dongyang Wei & Aimin L, Science of the Total Environment , 699, Jan. 2020, https://doi.org/10.1016/j.scitotenv.2019.134369. Reuse of pulp-and-paper industry wastewater as reclaimed water is an effective way to mitigate water resource shortage. In this study, the feasibility and safety of papermaking wastewater for the use as ecological water supplement after the treatment by fluidized-bed Fenton (FBF) coupled with constructed wetland (CW), were investigated from laboratory-scale to large-scale field. The optimum pH, H2O2, H2O2/Fe2+ ratio and hydraulic retention time (HRT) of FBF were 3.5, 0.93 mL/L, 4 and 60 min, respectively, based on reduction of both total organic carbon (TOC) and genotoxicity. Furthermore, the safety of effluent was evaluated using SOS/umu assay and 8-hydroxy-2-deoxyguanosine (8-OHdG) in zebrafish. Results showed FBF followed by CW improved the conventional water quality indicators and reduced the toxicity. Average removal rates of chemical oxygen demand (COD), ammonia nitrogen (NH3-N), total nitrogen (TN), total phosphorus (TP) and colority were 87.3%, 93.59%, 51.73%, 84.75% and 95.86%, respectively. The equivalent concentration of 4- nitroquinoline 1-oxide (4-NQO- EQ) decreased from 30.6 ± 1.6 μg/L in influent to 12.4 ± 1.0 μg/L after treated by FBF, then decreased to 5.9 ± 0.4 μg/L after treated by CW and to 3.2 ± 0.3 μg/L after 12 -km downstream self-purification. The chronic survival rates of 21- d zebrafish significantly increased from 0.0% in influent to 58.8 ± 4.0% in effluent of CW and gradually increased to 68.8 ± 2.6% after 12 -km downstream self-purification. Similarly, 8- OHdG level in zebrafish decreased from 120.0 ± 19.3 ng/L in effluent of ecological oxidation pond to 94.0 ± 7.5 ng/L in effluent of CW and grad ually decreased to 42.0 ± 3.0 ng/L after 12 -km downstream self-purification. The study concluded that FBF- CW is an efficient detoxication and water quality improvement technology for papermaking wastewater to be used as an ecological water supplement. Impact of persulphate mixed with paper sludge on activated sludge dewaterability, Sen Wang, Saige Cheng, Xueli Xiao & Fan Lai, Water and Environment Journal , online, https://doi.org/10.1111/wej.12597, FeSO4 was used to activate K2S2O8 mixed with paper sludge to condition activated sludge, and its effect on sludge dewaterability was investigated. Interaction effects of various parameters on sludge dewaterability were investigated and analysed by considering the moisture content of cake, specific resistance
Technical Abstracts
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