膜萃取处理高盐水杨酸废水传质特性研究

采用膜萃取分离法处理高盐水杨酸废水。讨论了料液流量F、反应温度T、萃取液pH值、料液进水浓度Cf,in等因素对膜传质性能和水杨酸去除效果的影响。结果表明:总传质系数Kov受料液流量和反应温度两因素影响较大;在Cf,in=854.2±19.7 mg/L、F=3 L/d、T=323 K、萃取液侧pH=11.5±0.2、膜管长L=50 m的条件下,水杨酸去除率可达97%。     

鸟粪石法处理高浓度氮磷废水的动态试验研究

本研究以实验室模拟的高浓度氮磷废水为研究对象,采用折流式反应器,探讨了在动态条件下,pH、Mg：P、N：P及水力停留时间对鸟粪石法脱氮除磷的影响。试验结果表明：对于氨氮的去除率,以上四个因素影响相当;对于磷的除率,各因素的影响大小为：N：P〉pH〉Mg：P〉水力停留时间。当模拟水样中的TP浓度为310mg／l,pH为9．7,水力停留时间为60min,Mg：N：P=1．2：1．2：l时,氨氮和磷的去除率分别可高迭85．8％和86．3％。     

中山市城区建筑物抗震能力与抗震措施研究

通过对广东省中山市城区建筑物震害预测的分析研究,明确了中山市城区当前建筑物存在的抗震薄弱环节,确定了危旧房屋集中地段的分布,给出了中山市城区建筑物抗震能力综合评价,对重要建筑物的安全程度做出了判断,最后提出了提高建筑物抗震能力的抗震措施。     

Variation of spatio-temporal distribution of on-road vehicle emissions based on real-time RFID data

High-resolution vehicular emissions inventories are important for managing vehicular pollution and improving urban air quality. This study developed a vehicular emission inventory with high spatio-temporal resolution in the main urban area of Chongqing, based on real-time traffic data from 820 RFID detectors covering 454 roads, and the differences in spatio-temporal emission characteristics between inner and outer districts were analysed. The result showed that the daily vehicular emission intensities of CO, hydrocarbons, PM_2.5, PM₁₀, and NOx were 30.24, 3.83, 0.18, 0.20, and 8.65 kg/km per day, respectively, in the study area during 2018. The pollutants emission intensities in inner district were higher than those in outer district. Light passenger cars (LPCs) were the main contributors of all-day CO emissions in the inner and outer districts, from which the contributors of NOx emissions were different. Diesel and natural gas buses were major contributors of daytime NOx emissions in inner districts, accounting for 40.40%, but buses and heavy duty trucks (HDTs) were major contributors in outer districts. At nighttime, due to the lifting of truck restrictions and suspension of buses, HDTs become the main NOx contributor in both inner and outer districts, and its three NOx emission peak hours were found, which are different to the peak hours of total NOx emission by all vehicles. Unlike most other cities, bridges and connecting channels are always emission hotspots due to long-time traffic congestion. This knowledge will help fully understand vehicular emissions characteristics and is useful for policymakers to design precise prevention and control measures.     

Interfacial mechanisms of heterogeneous Fenton reactions catalyzed by iron-based materials: A review

The heterogeneous Fenton reaction can generate highly reactive hydroxyl radicals(·OH)from reactions between recyclable solid catalysts and H_2O_2 at acidic or even circumneutral pH.Hence,it can effectively oxidize refractory organics in water or soils and has become a promising environmentally friendly treatment technology.Due to the complex reaction system,the mechanism behind heterogeneous Fenton reactions remains unresolved but fascinating,and is crucial for understanding Fenton chemistry and the development and application of efficient heterogeneous Fenton technologies.Iron-based materials usually possess high catalytic activity,low cost,negligible toxicity and easy recovery,and are a superior type of heterogeneous Fenton catalysts.Therefore,this article reviews the fundamental but important interfacial mechanisms of heterogeneous Fenton reactions catalyzed by iron-based materials..OH,hydroperoxyl radicals/superoxide anions(HO_2./O_2~-.)and high-valent iron are the three main types of reactive oxygen species(ROS),with different oxidation reactivity and selectivity.Based on the mechanisms of ROS generation,the interfacial mechanisms of heterogeneous Fenton systems can be classified as the homogeneous Fenton mechanism induced by surface-leached iron,the heterogeneous catalysis mechanism,and the heterogeneous reaction-induced homogeneous mechanism.Different heterogeneous Fenton systems catalyzed by characteristic iron-based materials are comprehensively reviewed.Finally,related future research directions are also suggested.     

利用超临界水氧化反应系统处理有机废液的经济性分析

超临界水氧化技术是一种能够高效分解有机废物的新型环境友好技术。以质量平衡方程和能量平衡方程为基础,对废液处理量为300 m3/d利用水膜反应器超临界水氧化反应系统的经济性进行分析,并同其他有机废液处理技术进行比较。结果表明:系统的能量利用率可达到56.4%;利用超临界水氧化技术处理有机废液的成本为33.05元/m3左右;该技术处理废液范围广,产物清洁,尤其适用于二恶英、多氯联苯等有毒有害难降解物质的处理,且反应能量和产物CO2可回收利用,不仅经济上可行,还具有很好的环境效益。     

大港发电厂温排水对附近海域浮游动物影响研究

分别于2010年夏、冬季对大港发电厂温排水口附近海域浮游动物进行调查。结果表明:调查区浮游动物以桡足类和幼虫类占优势,群落结构相对稳定,但丰度明显低于渤海湾其他海区,种类组成、丰度和多样性指数具有夏季高于冬季、近岸低于远岸的时空变化特征。临近温排水口的TJHS1117站位的浮游动物群落物种数、丰度及多样性等在6个调查站位中都处于最低,可见温排水对浮游动物群落结构及平面分布有一定的影响。     

玉米根系形态对土壤Cd和芘复合污染的响应

植物根系在逆境胁迫下通过改变其形态及分布来适应不利的生长环境,根系的形态变化是植物适应外界环境（特别是土壤环境）的一个重要机制。采用盆栽模拟试验探讨了Cd＋芘复合污染对两种基因型玉米（Zeamays L.）（白玉米和黑玉米）根系形态学参数（根长、根表面积、根体积、根平均直径及不同根直径等级分布）的定量化影响。与对照未污染相比,Cd＋芘复合污染显著降低了白玉米和黑玉米茎叶和根的生物量,特别是根的生物量。Cd＋芘复合污染对白玉米生物量的抑制要比对黑玉米要灵敏。与未污染相比,Cd＋芘复合污染下白玉米和黑玉米的根长稍有增长,根表面积、根平均直径和根体积减小,但两处理间差异不显著。白玉米和黑玉米每一级根直径的根长在Cd＋芘复合污染和未污染处理间没有显著差异。白玉米和黑玉米〉0.60mm的根的根表面积在Cd＋芘复合污染下显著降低。此研究结果为重金属-多环芳烃复合污染土壤植物毒理效应和植物修复技术的进一步研究奠定基础。     

岩溶山区不同土地利用方式对土壤活性有机碳动态的影响

对贵州茂兰自然保护区内三种典型土地利用方式(林地、草地和耕地)下土壤活性有机碳组分(土壤溶解有机碳和土壤微生物量碳)的月变化及其对环境因子的响应进行了研究,结果表明在不同的土地利用方式下上覆植被类型不同,其凋落物数量、质量及分解行为不同,有机质的输入量及质量也不相同,从而形成不同的土壤溶解有机碳含量差异,土壤有机碳的大小也存在较大差别。研究结果显示:从全年平均值来看,林地土壤溶解有机碳分别比草地和耕地高25%、48%;从3月到8月,三者均随气温的上升呈增加的趋势,林地和耕地在8月均达到最大值,而草地则在10月达到最大值;林地和草地土壤微生物量碳分别高于耕地81%和45%,林地和草地在10月达到最大值。不同的土地利用方式导致土壤活性有机碳的差异较大,这说明岩溶生态系统中土地利用方式对土壤碳库的大小有较大影响。不同土地利用方式下土壤活性有机碳对环境因子的响应也各不相同,这表明土壤活性碳受众多因素的制约而呈现出一种动态平衡关系,进一步的机理仍需要进行深入研究。     

城市污泥植物处理对地表径流和下层土壤的影响

城市污泥的农业利用逐渐成为世界城市污泥处理处置的最具前景的方式之一。通过设置无污泥+不种植物、污泥+不种植物、污泥+东南景天单种、污泥+东南景天与香芋套种4个处理,对污泥植物处理系统的地表径流以及各处理1年后的下层土壤(20~40 cm)进行了监测。研究结果表明:地表径流中的TN、TP和COD的含量随着时间的推移均有不断下降的趋势,其中,地表径流中的TP含量超出国家污水综合排放中的二级标准。地表径流中Zn、Cd、Cu和Pb的含量随着时间的推移略有上升的趋势,但它们的含量远低于国家污水综合排放标准中的二级标准。处理1年后下层土壤中的氮磷钾和有机质含量明显提高,下层土壤中的Zn、Cd、Cu和Pb含量也有一定程度的增加。