摘要
含酚类废水所含有毒有害物质主要为苯酚,其排放量大,微溶于水且毒性较大,难以彻底处理.利用具有吸附性和催化性的CuO/Ac (活性炭负载CuO)催化过硫酸盐产生强氧化性的SO4-·(硫酸根自由基)对模拟废水中苯酚进行降解,研究了不同因素(如反应温度、pH、水浴时间、CuO负载比、过硫酸盐投加量)对反应前、后模拟废水中苯酚和CODCr的去除率,并通过正交试验对这些因素进行了优化.结果表明:(1)过硫酸盐高级氧化法对苯酚的去除过程以氧化降解为主,在投加0. 2 g负载比为1∶5的CuO/Ac和过硫酸盐前提下,反应条件为pH 3、反应温度65℃,经过6 h的水浴反应,CuO/Ac催化过硫酸盐对于模拟废水中苯酚和CODCr的去除率分别可达到96. 83%和91. 90%.(2)通过正交试验得出,影响苯酚去除率大小的因素依次为反应温度>反应时间>pH,影响CODCr去除率大小的因素依次为反应温度>pH>反应时间.(3)在酸性、强碱性、高温条件下反应体系对苯酚的降解作用更明显,苯酚降解过程为先开环再进一步降解;相对于单独采用过硫酸盐和活性炭催化过硫酸盐法,采用活性炭负载CuO催化过硫酸盐法对模拟苯酚废水中苯酚具有去除率高、节省成本、处理速度快等优点.研究显示:在相同的试验设计情况下,应先考虑温度对反应的影响;在反应温度相同的条件下,根据对苯酚或对CODCr的去除率的不同要求,分别优先考虑反应时间、pH对试验的影响.
Phenol is the primary harmful substance in phenol-containing wastewater.It is slightly soluble in water,has large emission volume and high toxicity,and is difficult to remove completely.CuO-modified activated carbon,with both adsorptive and catalytic properties,can catalyze persulfate to produce sulfate radicals SO 4-·,with strong oxidizing properties,is able to degrade phenol in wastewater.The effects of different factors(reaction temperature,pH value,reaction time,amount of CuO,and sodium persulfate dosage)on the removal efficiency of phenol and COD Cr were examined.Orthogonal experiments were used to optimize these factors.The results showed that oxidative degradation was the main process of phenol removal by the persulfate-induced advanced oxidation method.When activated carbon with CuO loading ratio of 1∶5 and 0.2 g of sodium persulfate were added,and when the reaction conditions were pH=3 and T=65℃,the degradation efficiency of phenol and COD Cr in simulated wastewater by CuO-modified activated carbon in 6 h reached 96.83%and 91.90%,respectively,in 6 h.Using orthogonal experiments,it was found that the order of the influence rate on phenol degradation was:reaction temperature>reaction time>pH,while the order of influence rate on COD Cr removal was:reaction temperature>pH>reaction time.The research showed that the reaction system has greater catalytic phenol degradation capability under acidic and strong alkaline conditions.High reaction temperature was also beneficial to this reaction.In the degradation process,the phenol ring opened first,and then further degradation took place.Compared with catalysis by persulfate or activated carbon alone,the catalytic degradation of phenol by CuO-modified activated carbon shows the advantages of high degradation percentage,cost reduction and rapid degradation rate.When using this process to treat phenol-contaminated wastewater,the temperature should be preferentially controlled;under the same conditions of temperature,the effects of reaction time and pH on removal
作者
李一凡
王应军
廖鑫
LI Yifan;WANG Yingjun;LIAO Xin(College of Environmental Sciences,Sichuan Agricultural University,Chengdu 611130,China)
出处
《环境科学研究》
EI
CAS
CSCD
北大核心
2018年第11期1949-1956,共8页
Research of Environmental Sciences
基金
四川省科技厅科技支撑计划苗子工程重大项目(No.035Z1108)~~
关键词
活性炭
氧化铜
过硫酸盐
苯酚
高级氧化法
activated carbon
copper oxide
persulfate
phenol
advanced oxidation technology
