摘要
为有效地回收甲苯液相氧化法生产苯甲酸的工业废水中的苯甲酸和乙酸 ,并配合废水生物降解的末端处理技术 ,研究了 2 0 % ,30 %和 5 0 %磷酸三丁酯 (TBP) /煤油的混合溶剂、正辛醇和甲苯萃取苯甲酸稀溶液特性 ,以及对工业废水处理的实验 .结果表明 ,TBP对苯甲酸稀溶液具有良好的萃取作用 ,而纯溶剂体系与溶剂的极性有关 ,正辛醇的萃取能力与 30 %TBP相当 ;残液中的CODCr值由萃取剂在水中的溶解和苯甲酸自身的CODCr值组成 ,其中残液中溶剂溶解导致的CODCr值随其中苯甲酸浓度变化不明显 ,且CODCr值的大小为 :5 0 %TBP≈ 30 %TBP >正辛醇 >2 0 %TBP >甲苯 .针对工业废水中主要含有苯甲酸和乙酸的工况 ,提出了废水资源化的处理工艺流程 ,即首先采用甲苯进行废水中苯甲酸的回收 ,之后 ,再利用三烷基氧磷 /煤油为萃取剂回收废水中的醋酸 。
Extraction equilibrium of benzoic acid were studied using 20%, 30% and 50% tributyl phosphate (TBP) in kerosene, 1-octanol and toluene as the extractants, to investigate the efficient method of recovering benzoic and acetic acid in the industrial effluent and meeting the requirement of the terminal wastewater treatment. The COD Cr value in residual phase and the recovery of benzoic acid in various extractants were measured. The results showed that the recovery of benzoic acid was closed to 100% with 50%TBP/ kerosene system, and depended on the polarity of extractant for pure solvent system. The recovery with 1-octanol was equivalent to the one with 30%TBP. The COD Cr value in the residual phase depended on the COD Cr value from benzoic acid and the solubility of extractant, which does not depend on the benzoic acid concentration in the residue phase apparently, and shown 50%TBP≈30%TBP>1-octanol>20%TBP>toluene. Meanwhile, the profitable diagram of pretreatment of industrial effluent with benzoic acid was suggested, i.e. firstly, extract benzoic acid with toluene and return the toluene to the benzoic acid reactor, then, extract acetic acid with trialkylphosphine oxide and back-extract the acetic acid with CaO or MgO to produce calcium magnesium acetate.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2004年第4期78-81,共4页
Environmental Science
基金
北京市科技三项基金项目 (H0 2 2 12 0 0 10 13 0 )
清华大学基础研究基金项目 (Jc2 0 0 10 3 6)
关键词
工业废水
萃取
磷酸三丁酯
正辛醇
CODCR
industrial effluent with benzoic acid
extraction
COD Cr
tributyl phosphate
1-octanol
