Exploration of spatial-temporal varying impacts on COVID-19 cumulative case in Texas using geographically weighted regression (GWR)

Environmental Science and Pollution Research - Since COVID-19 is extremely threatening to human health, it is significant to determine its impact factors to curb the virus spread. To tackle the...     

Sorption of DDTs on biofilms, suspended particles and river sediments: effects of heavy metals

The sorption by solid materials is one of the most important processes that affect the fate of hydrophobic organic pollutants in aquatic systems. Current studies focus on the sorption of hydrophobic pollutants by single natural solid material, whereas few studies compared the sorption behaviors of different solids. Furthermore, natural aquatic environment is a complex system where hydrophobic pollutants coexist with many other pollutants, but only limited studies reported the effects of coexisting components on the sorption. Here we studied the sorption of dichlorodiphenyltrichloroethanes (DDTs) by three common solids in natural water, i.e., biofilms, suspended particles and sediments. The effects of typical coexisting heavy metals on the sorption were also examined. The results show that the sorption is described by a dual-mode sorption model. Compared with sediments, more DDTs were sorbed by biofilms and suspended particles. Coexisting Pb, Cd and Cu increased the sorption of DDTs on sediments while decreasing the sorption on biofilms slightly, with little effect on the sorption on suspended particles. The different sorption behaviors of the solids were mainly determined by the composition of the solids: more organics were observed in biofilms and suspended particles.     

汾渭平原复杂地形影响下冬季PM2.5污染分布特征、来源及成因分析

汾渭平原受其复杂地形特征及产业结构影响,和京津冀、长三角地区一起被列为大气污染重点防治区域.本研究应用2014—2019年冬季中国环境监测总站汾渭平原各城市的六大空气污染物逐小时数据,结合欧洲中心ERA-5数据,利用HYSPLIT后向轨迹模型及T-model斜交旋转主成分分析法（PCT）,揭示过去6年汾渭平原冬季颗粒物浓度演变规律,厘清汾渭平原复杂地形影响下大气污染来源特征、潜在源区及成因,识别影响汾渭平原冬季空气污染的主要天气系统类型.HYSPLIT模拟结果表明,冬季喇叭口地形城市主要受本地和邻近区域污染源影响;山区盆地地形城市更易受到100~300 km距离以内污染源的传输影响,其中,来自陕北的气团对其影响最大;峡谷地形城市更易受到300~600 km范围内污染源的传输影响;平原地形城市的污染物浓度受区域传输的影响较大.影响汾渭平原冬季颗粒物重污染的天气系统可分为高压前部型、高压后部型、均压场型及低压倒槽型,其中,高压前部型是汾渭平原冬季重污染时段最易出现的天气形势.     

Spatio-temporal characteristics and control strategies in the early period of COVID-19 spread: a case study of the mainland China

Environmental Science and Pollution Research - COVID-19 has caused huge impacts on human health and the economic operation of the world. Analyzing and summarizing the early propagation law can help...     

基于氮掺杂碳量子点的制备及其对Hg2+的响应

以乙二胺和抗坏血酸为原料,通过一步水热法制备了水溶性的氮掺杂碳量子点(N-CQDs).研究了N-CQDs的形貌特征、光学性能和应用分析.表征结果说明,N-CQDs形态为均匀分散的球形,有明显的晶格条纹,抗光漂白性能良好,表面富有含氧官能团,具有良好的水溶性.此外发现N-CQDs还具有优良的荧光性能和荧光稳定性,量子产率可以高达12.29%.分析得出,Hg²⁺对N-CQDs在1.0—120μmol·L^-1范围内有一定的猝灭效应,可作为Hg²⁺的荧光探针,检出限达230 nmol·L^-1.     

高等师范院校环境教育的探讨

从分析高等师范院开展环境教育的历史背景出发，提出了开展环境教育的主要途径及方法。     

某污水处理厂倒置A2/O工艺中制药类污染物的去除规律分析

针对西安市某污水处理厂的倒置A2/O工艺,通过对主要构筑物的布点检测,分析了污水中4种制药类污染物非那西汀、咖啡因、吉非罗齐和胆固醇的浓度变化及其去除规律.结果表明,污水厂进水中非那西汀、咖啡因、吉非罗齐和胆固醇的浓度分别为8.22、127.31、12.93和5.61μg·L-1,整个污水处理工艺中,非那西汀、吉非罗齐和胆固醇主要是被格栅、曝气沉砂池和初沉池去除,咖啡因则以生物降解为主.A2/O生物反应池中,吉非罗齐和胆固醇以厌氧生物降解为主,非那西汀和咖啡因则以好氧生物降解为主.脱水污泥中非那西汀、咖啡因、吉非罗齐和胆固醇的含量分别为0.09、2.62、12.24和0.91μg·g-1,污泥对吉非罗齐的吸附效果最为显著.污水厂出水中制药类污染物的浓度为0.17～1.98μg·L-1,出水中咖啡因的浓度偏高因而需要做进一步的三级处理.