摘要
采用浸渍-煅烧法制备了Fe、Mn、Cu及其复合负载的γ-Al_2O_3纳米颗粒,采用了SEM-EDS、BET以及XRD等方法对制备得到的Mn_xO_y/γ-Al_2O_3、Cu_xO_y/γ-Al_2O_3、FexOy/γ-Al_2O_3以及FexCuyMnzOw/γ-Al_2O_3纳米颗粒进行了表征.结果表明,通过浸渍-煅烧法得到的四种纳米颗粒催化剂均可以和双氧水形成非均相类Fenton反应体系,产生大量羟基自由基,从而有效降解PVA大分子,降低废水中的PVA浓度.另外还通过BoxBehnken Design响应面分析法分别确定了Mn_xO_y/γ-Al_2O_3、Cu_xO_y/γ-Al_2O_3、FexOy/γ-Al_2O_3以及FexCuyMnzOw/γ-Al_2O_3纳米颗粒催化双氧水降解处理PVA的最佳工艺参数.利用GPC和GC-MS分析进一步表征PVA在不同催化剂条件下得到的降解产物后,分析结果表明:Fe、Mn、Cu复合负载的FexCuyMnzOw/γ-Al_2O_3纳米颗粒催化双氧水降解PVA的催化效果相对较好.当PVA初始反应浓度为1%,反应温度为60℃,催化剂投加量为0.5 g·L^(-1),双氧水投加量为60 mL·L^(-1)时,PVA的浓度下降率可以达到95%以上,降解产物粘均分子量达到1395,分子量下降率达到99%,降解小分子产物主要包括丁酮、苯甲醛、己醛以及乙酸等不饱和小分子.
MnxOy/γ-Al2O3,CuxOy/γ-Al2O3,FexOy/γ-Al2O3 and FexCuyMnzOw/γ-Al2O3 nano particles were prepared by a wet impregnation-calcination method and characterized by SEM-EDS,BET and XRD.Results revealed that the prepared MnxOy/γ-Al2O3,CuxOy/γ-Al2O3,FexOy/γ-Al2O3 and FexCuyMnzOw/γ-Al2O3 nano particles rapidly reacted with H2 O2 and produced large quantity of hydroxyl radicals.With the oxidation by hydroxyl radicals in heterogeneous Fenton-like process,PVA macromolecules in solution was effectively degraded and hence removed in aqueous solution.The Box-Behnken response surface analysis method was employed to investigate theoptimum degradation parameters of PVA using MnxOy/γ-Al2O3,CuxOy/γ-Al2O3,FexOy/γ-Al2O3 and FexCuyMnzOw/γ-Al2O3 particles.Gel permeation chromatography(GPC) and gas chromatography-mass spectrometry(GC-MS) were also used to further identify the products of PVA under different catalyst conditions.It demonstrated that the catalytic performance of FexCuyMnzOw/γ-Al2O3 particles was better than other three catalysts.The PVA removal efficiency was above 95 %while the reaction temperature was 60 ℃,initial concentration of PVA was 1 %,H2O2 dosage was60 min·L^-1 and FexCuyMnzOw/γ-Al2O3 dosage was 0.5 g·L^-1 respectively.Besides,the GPC detection also confirmed that PVA was effectively oxidized with a decreasing rate of about 99 %,for the molecular weight from 100773 to 1395.Based on GC-MS analysis,it turned out that the degradation products of PVA mainly included several unsaturated compounds of lower molecular weight,such as butanone,benzaldehyde,hexanal and acetic acid,etc.
作者
苏扬帆
李梦娟
葛明桥
SU Yangfan;LI Mengjuan;GE Mingqiao(College of Textile & Clothing, Jiangnan University, Wuxi, 214122, China;Key Laboratory of Eco-Textiles (Jiangnan University), Ministry of Education, Wuxi, 214122, China)
出处
《环境化学》
CAS
CSCD
北大核心
2018年第6期1272-1281,共10页
Environmental Chemistry
基金
国家高技术研究发展计划(2016YFB0302901-3)
中央高校基本科研业务费专项资金(JUSRP51723B)资助