UiO-66(Zr)@多孔陶瓷复合材料的制备及对络合态重金属EDTA-Cu(Ⅱ)的去除

本文采用多孔陶瓷作为基体制备了锆基金属有机骨架UiO-66@多孔陶瓷复合材料.通过扫描电子显微镜(SEM)、粉末X射线衍射(PXRD)、氮气吸附和傅里叶变换红外光谱(FTIR)等表征手段对比了氢氧化钠脱硅和乙二胺表面改性等基体活化方式对UiO-66(Zr)在多孔陶瓷表面负载情况的影响.结果表明,经过乙二胺表面改性的多孔陶瓷对UiO-66(Zr)的负载更均匀,负载效果更好.以EDTA-Cu(Ⅱ)为考察对象,研究了UiO-66(Zr)@乙二胺表面改性多孔陶瓷复合材料对络合态重金属的净化效能.结果表明,UiO-66(Zr)@多孔陶瓷复合材料在较宽的酸碱条件下(pH=3—9)对络合态重金属EDTA-Cu(Ⅱ)均表现出良好的吸附性能,饱和吸附量为1.17 mg·g~(-1),并可通过NaOH解吸再生,从而实现材料的重复利用.     

基于聚类方法下的柴油车排放颗粒物无机元素谱分析

近年来在大气污染的防治工作中,柴油车污染防治的重要性日渐凸显.本文通过测试和文献检索等方法收集了97组与柴油车排放颗粒物无机元素排放有关的数据,采用k-means均值聚类分析的方法对数据进行分类并对分类结果进行分析,得出柴油车无机元素排放占颗粒物比例的大致区间为:Si(0—4.62%)、Al(0—1.53%)、Ca(0—4.09%)、Na(0—2.61%)、Mg(0—2.68%)、K(0—0.85%)、Fe(0—3.4%)、Zn(0—0.54%)、Cu(0—1.49%)、Ni(0—0.06%),且所得无机元素的排放区间的置信水平均大于94%.同时得到的柴油车排放颗粒物无机元素分析结果,可以为后续柴油车排放颗粒物无机元素数据分析以及相关污染治理提供参考,进而促进我国大气环境质量的改善、更好地保障人们身体健康.     

UV-254 nm活化过硫酸盐降解麻黄碱的影响因素和机理

采用UV-254 nm活化过硫酸盐高级氧化技术去除水中污染物麻黄碱(EPH),并研究了其降解动力学过程和降解机理.考察了过硫酸盐(PS)投加量、EPH的初始浓度、不同pH值及不同离子(HCO~-_3、NO~-_3、Cl~-)对降解效果的影响.结果表明,UV-254 nm活化过硫酸盐工艺能有效去除实验条件下的EPH,其氧化降解反应符合二级动力学方程.EPH去除率随着PS投加量的增加而增大.pH对降解反应有较大的影响,在pH=7的条件下,反应速率最快,表观反应动力学常数(k_(obs))为0.467 min~(-1).进一步研究表明,HCO~-_3、NO~-_3和Cl~-对EPH的降解都存在抑制作用,在相同浓度下,其抑制程度依次为Cl~- NO~-_3 HCO~-_3.通过UPLC-MS/MS鉴定了麻黄碱降解的中间体,并提出了可能的降解机理和转化途径.     

宜兴市典型道路灰尘(＜150 μm)组分中重金属污染特征及风险评价

粒径小于150μm道路灰尘是生态系统及人类健康风险的主要来源.本文于2016年11月采集宜兴市主城区10条典型交通道路灰尘样品,分析并评价150μm灰尘颗粒中Zn、Cu、Pb、Ni和Cr等5种重金属污染及风险水平.研究结果表明,宜兴市道路灰尘中重金属含量均高于当地土壤背景值,平均含量(mg·kg~(-1))大小依次为:Zn(408.2±108.0)Pb(263.3±582.4)Cr(161.7±77.1)Cu(128.0±43.4)Ni(90.2±32.4).地累积指数(I_(geo))表明,道路灰尘中重金属Zn和Cu为中-中/重度污染水平,Pb表现为中度污染水平,Ni和Cr则表现为无污染/中-中度污染水平.潜在生态风险指数(RI)表明,研究区域(宜兴市)大部分道路的灰尘中重金属对当地生态系统造成潜在中度风险,重金属Cu、Cr和Pb为潜在生态风险主要来源(85%).健康风险评价表明,道路灰尘中非致癌重金属对儿童可能构成潜在非致癌风险,对成人不造成非致癌伤害, Ni和Cr对暴露人群不会造成严重致癌危害.研究同时发现,宜兴市道路灰尘中重金属污染程度严重,亟需采取有效措施加以控制.     

Degradation of polyacrylamide (PAM) and methane production by mesophilic and thermophilic anaerobic digestion: Effect of temperature and concentration

• PAM degradation in thermophilic AD in comparison with mesophilic AD. • PAM degradation and its impact on thermophilic and mesophilic AD. • Enhanced methane yield in presence of PAM during thermophilic and mesophilic AD. • PAM degradation and microbial community analysis in thermophilic and mesophilic AD. Polyacrylamide (PAM) is generally employed in wastewater treatment processes such as sludge dewatering and therefore exists in the sludge. Furthermore, it degrades slowly and can deteriorate methane yield during anaerobic digestion (AD). The impact or fate of PAM in AD under thermophilic conditions is still unclear. This study mainly focuses on PAM degradation and enhanced methane production from PAM-added sludge during 15 days of thermophilic (55°C) AD compared to mesophilic (35°C) AD. Sludge and PAM dose from 10 to 50 g/kg TSS were used. The results showed that PAM degraded by 76% to 78% with acrylamide (AM) content of 0.2 to 3.3 mg/L in thermophilic AD. However, it degraded only 27% to 30% with AM content of 0.5 to 7.2 mg/L in mesophilic AD. The methane yield was almost 230 to 238.4 mL/g VSS on the 8th day in thermophilic AD but was 115.2 to 128.6 mL/g VSS in mesophilic AD. Mechanism investigation revealed that thermophilic AD with continuous stirring not only enhanced PAM degradation but also boosted the organics release from the sludge with added PAM and gave higher methane yield than mesophilic AD.     

NOx attenuation in flue gas by •OH/SO4•--based advanced oxidation processes

Environmental Science and Pollution Research - The combustion of fossil fuels has resulted in rapidly increasing emissions of nitrogen oxide (NOx), which has caused serious human health and...