School of Environmental and Chemical Engineering, Tianjin Polytechnic University, Tianjin 300387, PR China; State Key Laboratory of Separation Membranes and Membrane Processes, Tianjin 300387, PR China.
School of Environmental and Chemical Engineering, Tianjin Polytechnic University, Tianjin 300387, PR China.
Chemosphere. 2018 Sep;206:238-247. doi: 10.1016/j.chemosphere.2018.04.172. Epub 2018 May 4.
Coagulation-sedimentation combined with sponge iron/ozone (CS-SFe/O) technology was applied to pretreat water-based seed coating wastewater (WSCW) from pesticide manufacturing. Coagulation with polyferric sulfate at a dosage of 1.5 g L and a pH of 8.0 was effective, with color and chemical oxygen demand (COD) removal rates of 96.8 and 83.4%, respectively. SFe/O treatment further reduced the organic content in the effluents, especially concerning the degradation of aromatic pollutants, as demonstrated via ultraviolet-visible spectrophotometry (UV-vis), excitation-emission matrix (EEM) fluorescence spectrometry, and gas chromatography-mass spectrometry (GC/MS) analyses. The residual color and COD values of the effluent were 581.0 times and 640.0 mg L, respectively, under optimal conditions (ozone concentration of 0.48 mg L, SFe dosage of 20.0 g L, initial pH of 9.0, and reaction time of 30 min). Organic pollutants were also degraded by the high amounts of HO, which may have been generated via the transformation of ozone into HO on the SFe's surface and in the solution. Meanwhile, the biochemical oxygen demand (BOD)/COD ratio of the WSCW increased, which indicates that the biodegradability improved significantly. The amount of iron leached from SFe particles was 4.5 mg L, which shows that the SFe catalyst has good stability. The operating cost of the combined CS-SFe/O technology was estimated at approximately 2.79 USD t. The results of this study suggest that the application of the combined CS-SFe/O technology in WSCW pretreatment can be beneficial for removing suspended solids, degrading recalcitrant pollutants, and enhancing biodegradability for the subsequent bioprocessing treatment.
混凝-沉淀联合海绵铁/臭氧（CS-SFe/O）技术被应用于农药制造用水基种衣剂废水（WSCW）的预处理。在 pH 值为 8.0 时，聚合硫酸铁投加量为 1.5 g/L 时混凝效果较好，对废水的色度和化学需氧量（COD）去除率分别达到 96.8%和 83.4%。SFe/O 处理进一步降低了废水中的有机含量，特别是芳香族污染物的降解，这通过紫外-可见分光光度法（UV-vis）、激发-发射矩阵（EEM）荧光光谱法和气相色谱-质谱（GC/MS）分析得到证实。在最优条件下（臭氧浓度为 0.48 mg/L，SFe 投加量为 20.0 g/L，初始 pH 值为 9.0，反应时间为 30 min），出水的残余色度和 COD 值分别为 581.0 倍和 640.0 mg/L。在 SFe 表面和溶液中，臭氧转化为 HO 产生的大量 HO 也降解了有机污染物。同时，WSCW 的生化需氧量（BOD）/COD 比值增加，表明生物降解性显著提高。从 SFe 颗粒中浸出的铁量为 4.5 mg/L，表明 SFe 催化剂具有良好的稳定性。CS-SFe/O 联合技术的运行成本估计约为 2.79 美元/t。该研究结果表明，将 CS-SFe/O 联合技术应用于 WSCW 的预处理，有利于去除悬浮物、降解难降解污染物、提高后续生物处理的生物降解性。
