摘要
为了评价Fe(Ⅲ)/Fe(Ⅱ)铁氧体工艺对PVA(聚乙烯醇)废水处理的可行性,采用Fe(Ⅲ)/Fe(Ⅱ)铁氧体工艺原位处理PVA模拟废水,考察不同作用时间、总铁投加量、初始ρ(PVA)和废水硬度对该工艺处理效果的影响.利用XRD(X射线衍射)、FT-IR(傅里叶转换红外光谱)、BET比表面积、VSM(磁滞回线测试)对沉淀物进行表征,解析该工艺原位处理PVA模拟废水的主要机理,并以该工艺沉淀物为吸附剂,通过锑吸附试验,探讨该工艺沉淀物的回用性.结果表明:(1)Fe(Ⅲ)/Fe(Ⅱ)铁氧体工艺对PVA模拟废水具有良好的处理能力,初始ρ(PVA)为1 000 mg/L时,该工艺在20 min以内即可达到80%以上的去除率,并且基本没有金属铁的残余,该工艺对PVA的去除率随总铁投加量的增加而提高且基本不受水体硬度影响.(2)在Fe(Ⅲ)/Fe(Ⅱ)铁氧体工艺对PVA的原位去除过程中,PVA作为一种反应物参与沉淀物Fe3O4的生成,并促进纳米Fe3O4比表面积增大,最终形成一种类似于凝胶的Fe3O4聚合物.(3)Fe(Ⅲ)/Fe(Ⅱ)铁氧体工艺可高效处理模拟PVA-MB(亚甲基蓝)染料废水.对于含有100 mg/L MB(亚甲基蓝三水)和500 mg/L PVA的混合溶液,MB和CODCr去除率在1 min时分别达到97. 37%和89. 47%.沉淀物通过磁分离、乙醇和水清洗后,在水中浸出的ρ(TOC)和ρ(CODCr)很低,分别为0. 86和2 mg/L,可作为吸附剂直接使用,得益于其具有较高的比表面积,对金属锑的拟合吸附量可达71. 94 mg/g.(4)Fe(Ⅲ)/Fe(Ⅱ)铁氧体工艺具有一定的实际应用价值.对东莞某实际印染废水处理5 min,CODCr和染料的去除率分别为85. 71%和98. 98%.研究显示,Fe(Ⅲ)/Fe(Ⅱ)铁氧体工艺可高效去除PVA,沉淀物为易回收的磁性Fe3O4,可作为吸附剂直接使用.
To investigate the applicability of Fe(Ⅲ) Fe(Ⅱ) ferrite process for PVA (polyvinyl alcohol) wastewater treatment, a Fe(Ⅲ) Fe(Ⅱ) ferrite process was used. Several operational conditions including reaction time, total iron dosage, initial PVA concentration and wastewater hardness were evaluated. The corresponding removal mechanisms were determined through characterization the final precipitates. The recyclability of the final precipitates was also investigated using the cleaned precipitates as an antimony adsorbent. The results show that:(1) The Fe(Ⅲ) Fe(Ⅱ) ferrite process exhibited a good performance in PVA wastewater treatment. When initial PVA concentration was 1000 mg L in the wastewater, more than 80% of PVA was removed within 20 minutes with almost no release of heavy metals. The PVA removal increased with increasing iron dosage and slightly depended on the hardness of wastewater.(2) PVA , as a reactant, increased the specific surface area of Fe 3O 4 formed during the treatment process and a gel-like Fe 3O 4 polymer was finally formed.(3) The Fe(Ⅲ) Fe(Ⅱ) ferrite process could efficiently treat simulated PVA-MB (methylene blue) dye wastewater. For simulated PVA-MB wastewater containing 100 mg L MB and 500 mg L PVA, after a minute treatment MB and COD Cr removal reached 97.37% and 89.47%, respectively. After magnetic separation and washing by ethanol and water, the TOC and COD Cr leaching from the precipitates was 0.86 and 2 mg L, respectively. Therefore, the precipitates could be directly reused as adsorbents. Due to the high surface area, the maximum antimony(Ⅲ) adsorption capacity of the precipitates was 71.94 mg g.(4)The Fe(Ⅲ) Fe(Ⅱ) ferrite process has practical value for engineering application. For an actual printing and dyeing wastewater from Dongguan, the removal rates of COD Cr and dye could reach 85.71% and 98.98% within 5 min, respectively. This study shows that the Fe(Ⅲ) Fe(Ⅱ) ferrite process is very effective for PVA removal, and the formed magnetite precipitates can be easily collected and directly reused.
作者
郝昊天
韩昆
石宝友
王毅力
HAO Haotian;HAN Kun;SHI Baoyou;WANG Yili(College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083,China;College of Petrochemical Engineering, Lanzhou University of Technology, Lanzhou 730050, China;Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Beijing 100085, China;University of Chinese Academy of Sciences, Beijing 100049, China)
出处
《环境科学研究》
EI
CAS
CSCD
北大核心
2019年第2期340-346,共7页
Research of Environmental Sciences
基金
国家重点研发计划项目(No.2016YFA0203204)
国家自然科学基金项目(No.51478041
51678053)~~
