偶氮染料在气-液-固循环浆态光催化反应器中的降解脱氮

Degradation and nitrogen removal of azo dye in gas-liquid-solid circulating slurry photocatalytic reactor

偶氮染料废水是一种集中量大的重要污染物,其中的偶氮键可被环境微生物降解生成具有毒性的芳香胺类化合物。本文从光量子效率、脱氮速率、脱氮能耗等方面,对比研究了一种新设计的气-液-固循环浆态光催化反应器和环隙式光催化反应器对偶氮染料降解脱氮的性能。结果表明,由于空气的引入,使气-液-固循环浆态光催化反应器的量子收率有一定程度下降,同时造成单位数量级脱氮能耗也有一定增大,但偶氮染料脱氮速率比在环隙式反应器中的情况有大幅度提高,表明气-液-固循环浆态反应器在偶氮染料废水光催化降解脱氮方面具有较大应用前景。

Textile industries discharge an amount of wastewater with various azo dyes.The azo bonds,NN,in azo dyes could be easily degraded into aromatic amines with toxicity to environment.The photocatalytic degradation of azo dyes can lead to the breakage of the azo bonds,forming gaseous nitrogen.In order to intensify the photocatalytic process,the degradation and nitrogen removal of an azo dye was comparatively investigated in a newly designed gas-liquid-solid circulating slurry photocatalytic reactor and a traditional annular photocatalytic reactor.The process parameters were first optimized for the two reactors,respectively,and then a comprehensive performance evaluation of the two reactors was compared under the optimized experimental conditions,with respect to the apparent quantum yield of azo dye degradation,the rate and electrical energy consumption of nitrogen removal.The results indicate that the introduction of air into the gas-liquid-solid circulating slurry reactor results in a lower apparent quantum yield and higher energy consumption of nitrogen removal compared with that in the annular reactor,but can obviously increase the nitrogen removal rate.Therefore,the gas-liquid-solid circulating slurry photoreactor exhibits a potential application in industrial area.