摘要
选用代表性蒙囿剂甲酸和柠檬酸以及皮胶原的水解产物明胶为对象,研究了这3种有机配体对Cr(Ⅲ)碱沉淀过程和耐碱性的影响分析,同时采用紫外可见光光谱及凝胶渗透色谱(GPC)对不同pH条件下的配合物变化进行了识别,分析了相应碱沉淀物热失重特点.研究结果表明:3种有机配体对Cr(Ⅲ)有不同程度的络合作用,形成的配合物的稳定性有较大差异,其稳定性与配合物的耐碱性顺序一致,依次顺序为:柠檬酸>明胶>甲酸.鞣制废水中铬与羟基羧酸型蒙囿剂络合是其难以去除的主要原因,胶原水解产物也会影响沉淀效果,同时发现有机配体与Cr(Ⅲ)可协同沉淀,鞣制废水中铬的彻底去除需先破除铬的络合物稳定性问题.
The non-compliance and complex composition of chromium in leather wastewater makes it significant to elucidate the effect of organic ligand on alkali precipitating behavior and alkali resistance of Cr（Ⅲ ）. Formic acid, citric acid and the hydrolyzate of collagen-gelatin were chosen as representative masking agents in this study with UV-visible spectroscopy and Gel permeation chromatography （GPC） for identifying changes of complexes under different pH conditions, and thermal gravimetric analysis for corresponding alkali precipitates. The results showed that the three organic ligands complexed with Cr（ Ⅲ ） to different degrees. The stability of the complexes formed are quite different, and the stability and alkali resistance of the complexes are both in the order： citric acid 〉 gelatin 〉 formic acid. The complexation of Cr（Ⅲ） with masking agent containing hydroxy carboxylic group makes it difficult to be removed in leather wastewater. Furthermore, the efficiency of precipitation would be affected by gelatin hydrolysate as well. Meanwhile, these organic ligands could coprecipitate with Cr（Ⅲ） during alkali precipitation. Therefore, the breaking down of these stable complexes is critical for complete removal of chromium in leather wastewater.
出处
《环境化学》
CAS
CSCD
北大核心
2014年第2期349-354,共6页
Environmental Chemistry
基金
国家自然科学基金项目(21177079)资助
关键词
甲酸
柠檬酸
明胶
Cr(Ⅲ)
碱沉淀
formic acid, citric acid, gelatin, Cr（Ⅲ）, precipitation.
