臭氧/活性炭/紫外光联用处理几种高浓度有机废水影响因素

以对硝基苯甲酸废水、鸟嘌呤废水、乙醛废水和乙醇胺废水为例,对臭氧/活性炭氧化去除废水中有机物的效果进行了初步研究,考察了臭氧投加量、pH值和紫外光等因素对臭氧/活性炭催化氧化高浓度有机废水的影响,并在最优条件下,验证了该工艺作为高浓度有机废水预处理手段,在去除废水中COD和提高可生化性(BOD5/COD)等方面的综合效果.结果表明,活性炭作为催化剂与臭氧共同作用,对对硝基苯甲酸废水COD的去除率明显高于单独臭氧氧化和活性炭吸附;臭氧/活性炭氧化对乙醛废水和乙醇胺废水这类短链类有机物降解作用不大,但对硝基苯甲酸废水、鸟嘌呤废水这些含有苯环类、长链类的有机物,去除效率较高;在中性偏碱时,pH的提高有利于COD的去除,但过高pH对COD的降解效果反而有所减弱,pH=9.0是比较合适的;在紫外光催化的条件下,采用臭氧/活性炭氧化工艺处理对硝基苯甲酸废水,COD去除率可达到52%,废水的生化性(BOD5/COD)由原来的0.10提高到0.32,大大提高了废水的可生化性.

Influencing factors of high-concentration organic wastewater treatment by O3/UV using granular activated carbon (GAC) as the catalyst

Ozonation combined with UVirradiation(O₃/UV)using granular activated carbon(GAC)as the catalyst was investigated as a pretreatment method for high-concentration organic wastewater.The effect of operating parameters such as ozone dosage,pH value and UV light irradiation;and the effectiveness of the process to remove COD and to increase biodegradation capacity(BOD5/COD ratio)was also examined under the optimum conditions.The results showed that the COD removal efficiency of paranitrobenzoic acid wastewater by ozonation using GAC as the catalyst was much higher than either ozonation or GAC catalytic treatment alone.The removal efficiencies of long chain aromatic organics in wastewater,such as paranitrobenzoic acid and guanine,were much better than those of short chain organics,such as acetaldehyde and ethanolamine.It was also found that COD removal increased with increasing pH values in neutral and alkaline solutions while excessive alkalinity weakened CODremoval.ApHvalue of 9.0 was most suitable.The CODremoval of paranitrobenzoic acid wastewater by the O₃/GAC/UV process was 52%,and the BOD5/COD ratio increased from 0.10 to 0.32,indicating that the biodegradation capacity was greatly improved.