酸析-活性炭纤维吸附预处理精制棉黑液

Pretreatment of black liquor from refined cotton production by acidification and adsorption using activated carbon fiber

采用酸析-活性炭纤维吸附工艺去除精制棉黑液中的有机物,先用酸析法去除木质素,再用活性炭纤维吸附黑液中的剩余有机物。采用紫外-可见(UV-vis)吸收光谱、傅立叶转换红外吸收光谱(FTIR)和明亮发光菌水质急性毒性法等手段分析处理前后的精制棉黑液。研究表明,黑液中主要有机成分为愈创基(G-)和羟苯基(H-)木质素。在pH为2.0,活性炭纤维用量为90 g/L,温度为40°C,吸附时间为5 h的条件下,COD去除率可以达到85%。活性炭纤维对酸析后精制棉黑液的吸附热力学符合Redlich-Peterson经验吸附模型,吸附动力学符合伪二级动力学模型,吸附为吸热过程。酸析-吸附过程使精制棉黑液急性毒性去除率达到95%以上,为后续生物法处理提供了有利条件。

Acidification and activated carbon fiber （ACF） adsorption were investigated for removal of organic pollutants from black liquor generated from refined cotton production. Acidification is to remove lignin, while ACF adsorption is to remove the remaining organic matters from black liquor. UV-vis spectroscopy, FTIR were used to evaluate the chemical changes of black liquor. The acute toxicity of black liquor before and after adsorption was evaluated by bacterial bioluminescence assays. The results indicated that the main organic components of black liquor are guaiacyl （G-） and hydroxyphenyl （H-） lignin. When pH = 2.0 for acid precipitation, ACF dosage was 90 g/L, 85% of COD could be removed after 5 h of adsorption at 40℃. The adsorption process can be described by Redlich-Peterson isotherm model. The kinetic data followed the pseudo-second-order equation and the adsorpton process was endothermic. After acidification and ACF adsorption, up to 95% of the acute toxicity of black liquor was removed, which may be favorable for further biological treatment.