改性橘皮吸附亚甲基蓝模拟废水的性能研究

采用干燥橘皮为基本材料,添加Na OH试剂改变其表面性质,对改性橘皮吸附亚甲基蓝模拟废水的性能及条件进行了研究。研究了温度、时间、转速、粒径、改性剂浓度、吸附剂用量对吸附效果的影响,并以此为基础采用正交试验设计找寻最佳吸附条件,得出最佳吸附条件为温度20℃,转速150 r/min,吸附时间30 min,粒径180目。采用以上吸附条件测出的去除率为96.3%,吸附效果良好。     

Biodegradation and ecotoxicological assessment of pectin production wastewater

The chemical composition of pectin production wastewater and its toxicity during biological treatment were investigated. Samples of wastewater from di erent steps of a pectin production wastewater biological treatment plant were investigated including the influent of the treatment (1), after denitrification tank (2), after anaerobic treatment (3) and final e uent (4). The conventional physicochemical characteristics of samples did not indicate wastewater toxicity. However, toxicity assessments carried out on Vibrio fischeri and Scenedesmus subspicatus indicated low EC50 values. The fractionation of the samples using an XAD resin showed that the toxicity was associated with the organic matter. Wastewater apparent molecular mass distributions were 14.3, 25.0, 24.4 and 29.6 kDa for samples 1–4, respectively. Finally, characteristics of the sample by pyrolisis-gas chromatography-mass spectrometry (Py-CG-MS) demonstrated its polyphenolic nature and a 23% increase in the levels of such compounds after the first biological treatment step.