Fast and efficient aqueous arsenic removal by functionalized MIL-100(Fe)/rGO/δ-MnO2 ternary composites: Adsorption performance and mechanism

Because of its significant toxicological effects on the environment and human health,arsenic(As) is a major global issue.In this study,an Fe-based metal-organic framework(MOF)(Materials of Institut Lavoisier:MIL-100(Fe)) which was impregnated with reduced graphene oxide(rGO) by using a simple hydrothermal method and coated with birnessitetype manganese oxide(δ-MnO_2) using the one-pot reaction process(MIL-100(Fe)/rGO/δ-MnO_2 nanocomposites) was synthesized and applied successfully in As removal.The removal efficiency was rapid,the equilibrium was achieved in 40 min and 120 min for As(Ⅲ) and As(Ⅴ),respectively,at a level of 5 mg/L.The maximum adsorption capacities of As(Ⅲ) and As(Ⅴ) at pH 2 were 192.67 mg/g and 162.07 mg/g,respectively.The adsorbent revealed high stability in pH range 2-9 and saturated adsorbent can be fully regenerated at least five runs.The adsorption process can be described by the pseudo-second-order kinetic model and Langmuir monolayer adsorption.The adsorption mechanisms consisted of electrostatic interaction,oxidation and inner sphere surface complexation.     

温岭市制鞋业污染现状及环境整治对策

温岭市制鞋业由于数量众多,分布密集,生产总量较大,污染防治设施滞后,而被列入台州市8．11环境保护新三年行动计划重点整治行业,但在实施过程中,进度缓慢,步履艰难。为此笔者全面调查了温岭制鞋业空间分布特征、发展趋势、产品结构以及产排污状况,系统地分析了该行业的污染现状,进而剖析成因,提出了切实可行的行业污染环境整治对策。     

Functional rGO aerogel as a potential adsorbent for removing hazardous hexavalent chromium: adsorption performance and mechanism

Environmental Science and Pollution Research - A novel functional rGO aerogel was synthesized by a facile hydrothermal method. In this process, graphene oxide (GO) was used as the precursor and...     

Meteorological mechanism for a large-scale persistent severe ozone pollution event over eastern China in 2017

An intensive and persistent regional ozone pollution event occurred over eastern China from 25 June to 5 July 2017.73 out of 96 selected cities,most located in the Beijing-TianjinHebei and the surrounding area(BTHS),suffered severe ozone pollution.A north-south contrast ozone distribution,with higher ozone(199±33 μg/m~3) in the BTHS and lower ozone(118±25 μg/m~3) in the Yangtze River Delta(YRD),was found to be dominated by the position of the West Pacific Subtropical High(WPSH) and mid-high latitude wave activities.In the BTHS,the positive anomalies of geopotential height at 500 hPa and temperature at the surface indicated favorable meteorological conditions for local ozone formation.Prevailing northwesterly winds in the mid-high troposphere and warm advection induced by weak southerly winds in the low troposphere resulted in low-moderate relative humidity(RH),less total cloud cover(TGC),strong solar radiation and high temperatures.Moreover,southerly winds prevailing over the BTHS aggravated the pollution due to regional transportation of O_3 and its precursors.On one hand,the deep sinking motion and inversion layer suppressed the dispersion of pollutants.On the other hand,O_3-rich air in the upper layer was maintained at night due to temperature inversion,which facilitated O_3 vertical transport to the surface in the next-day morning due to elevated convection.Generally,temperature,UV radiation,and RH showed good correlations with O_3 in the BTHS,with rates of 8.51(μg/m~3)/℃(within the temperature range of 20-38℃),59.54(μg/m~3)/(MJ/m~2)and-1.93 μg/m~3)/%,respectively.     

温岭市制鞋业产排污系数的核算研究

针对温岭市制鞋业原料、工艺、产品基本相同的特点,筛选大、中、小3种规模的制鞋企业进行抽样调查.采用查询历史资料、票据核查、实地勘察和现场监测相结合的办法,收集相关数据,分别用物料衡算法和监测法核算制鞋业的产排污系数.随机选取3家企业对主要污染因子甲苯的产污系数进行验证.应用偏差在-11%～19%.