长三角地区一次区域污染过程中细颗粒物的来源解析及其光学特性

为研究长三角地区细颗粒物污染的分布特征及其光学特性,选择在城市(苏州)、郊区(南京)和区域背景站(临安)同时进行PM2.5采集并进行化学分析.这次污染过程中,苏州、南京和临安的PM2.5平均浓度分别达到(169.8±56.5)、(169.9±51.2)和(154.0±54.9)μg·m-3.散度系数分析显示3 个站点气...     

Simplified creation of polyester fabric supported Fe-based MOFs by an industrialized dyeing process: Conditions optimization, photocatalytics activity and polyvinyl alcohol removal

MIL-53(Fe) was successfully prepared and deposited on the surface carboxylated polyester (PET) fiber by an optimized conventional solvothermal or industrialized high temperature pressure exhaustion (HTPE) process to develop a PET fiber supported MIL-53(Fe) photocatalyst ([email protected]) for the degradation of polyvinyl alcohol (PVA) in water under light emitting diode (LED) visible irradiation. On the basis of several characterizations, [email protected] was tested for the photocalytic ability and degradation mechanism. It was found that temperature elevation significantly enhanced the formation and deposition of MIL-53(Fe) with better photocatalytic activity. However, higher temperature than 130°C was not in favor of its photocatalytic activity. Increasing the number of surface carboxyl groups of the modified PET fiber could cause a liner improvement in MIL-53(Fe) loading content and photocatalytic ability. High visible irradiation intensity also dramatically increased photocatalytic ability and PVA degradation efficiency of [email protected] Na₂S₂O₈ was used to replace H₂O₂ as electron acceptor for further promoting PVA degradation in this system. [email protected] prepared by HTPE process showed higher MIL-53(Fe) loading content and slightly lower PVA degradation efficiency than that prepared by solvothermal process at the same conditions. These findings provided a practical strategy for the large-scale production of the supported MIL-53(Fe) as a photocatalyst in the future.     

Ag， Fe， Ce对ZnTi-LDO可见光催化性能的影响及作用机理

为了解金属及其氧化物对锌钛类水滑石衍生氧化物（ZnTi-LDO）可见光催化性能的影响，并获得在可见光下可快速降解染料的LDO光催化剂，制备了Ag、Fe、Ce修饰的复合材料（M-ZnTi-LDO,M=Ag,Ag₂O,Fe,Ce）.通过XRD、TEMHRTEM、XPS、BET、UV-Vis、PL对所合成材料的结构、形貌、表面化学状态、光学性质进行了表征，评价了上述材料在可见光下对亚甲基蓝（MB）的催化降解性能，通过自由基捕获实验确定了催化降解活性物种，提出了相关催化机理.结果表明，Fe、Ce金属氧化物及金属Ag抑制了材料的可见光催化性能，Ag₂O则显著提升了ZnTi-LDO的可见光催化性能.Ag₂O-ZnTi-LDO在20 min内即可使MB降解率>98%，其表观降解速率常数是ZnTi-LDO的7倍.此外，Ag₂O-ZnTi-LDO稳定性良好，循环5次无催化性能下降.·O₂^-是Ag₂O-ZnTi-LDO催化降解MB的主要活性物种.A...     

空间溢出视角下的环境规制与绿色发展——困境还是协调？

绿色发展是未来经济发展的必然趋势，提升绿色全要素生产率是实现绿色发展的重要途径，环境规制是解决环境问题的有效保障。本文采用2004—2019年30个省级面板数据，构建动态空间杜宾模型，实证研究了环境总体规制、工业废气规制、工业废水规制、工业固体废物规制和光污染规制对绿色全要素生产率的空间溢出影响。研究发现，环境总体规制对本地绿色全要素生产率的影响呈U形，工业废气规制、工业废水规制和工业固体废物规制的研究结果存在同一规律，而光污染规制起抑制作用。总体规制对邻地绿色全要素生产率的影响呈倒U形，具体规制的影响各不相同，工业废气规制与总体规制的结果类似，而工业废水规制的空间溢出效应表现为负，工业固体废物规制和光污染规制的空间溢出效应不显著。本文从实证角度验证了“绿水青山”和“金山银山”的兼容性，环境规制和效率提升并不矛盾。在制定环境政策时，需考虑区域间的相互协调和实际产业情况。