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721.
In this study, the host-sensitivity and host-specificity of JC virus (JCV) and BK virus (BKV) polyomaviruses were evaluated by testing wastewater and fecal samples from nine host groups in Southeast Queensland, Australia. The JCV and BKV polyomaviruses were detected in 63 human wastewater samples collected from primary and secondary effluent, suggesting high sensitivity of these viruses in human wastewater. In the 81 animal wastewater and fecal samples tested, 80 were polymerase chain reaction (PCR) negative for the JCV and BKV markers. Only one sample (out of 81 animal wastewater and fecal samples) from pig wastewater was positive. Nonetheless, the overall host-specificity of these viruses to differentiate between human and animal wastewater and fecal samples was 0.99. To our knowledge, this is the first study in Australia that reports on the high specificity of JCV and BKV polyomaviruses. To evaluate the field application of these viral markers for detecting human fecal pollution, 20 environmental samples were collected from a coastal river. In the 20 samples tested, 15% (3/20) and 70% (14/20) samples exceeded the regulatory guidelines for Escherichia coli and enterococci levels for marine waters. In all, five (25%) samples were PCR positive for JCV and BKV, indicating the presence of human fecal pollution in the coastal river investigated. The results suggest that JCV and BKV detection using PCR could be a useful tool for identifying human-sourced fecal pollution in coastal waters.  相似文献   
722.
Floodplain forests provide unique ecological structure and function, which are often degraded or lost when watershed hydrology is modified. Restoration of damaged ecosystems requires an understanding of surface water, groundwater, and vadose (unsaturated) zone hydrology in the floodplain. Soil moisture and porewater salinity are of particular importance for seed germination and seedling survival in systems affected by saltwater intrusion but are difficult to monitor and often overlooked. This study contributes to the understanding of floodplain hydrology in one of the last bald cypress [Taxodium distichum (L.) Rich.] floodplain swamps in southeast Florida. We investigated soil moisture and porewater salinity dynamics in the floodplain of the Loxahatchee River, where reduced freshwater flow has led to saltwater intrusion and a transition to salt-tolerant, mangrove-dominated communities. Twenty-four dielectric probes measuring soil moisture and porewater salinity every 30 min were installed along two transects-one in an upstream, freshwater location and one in a downstream tidal area. Complemented by surface water, groundwater, and meteorological data, these unique 4-yr datasets quantified the spatial variability and temporal dynamics of vadose zone hydrology. Results showed that soil moisture can be closely predicted based on river stage and topographic elevation (overall Nash-Sutcliffe coefficient of efficiency = 0.83). Porewater salinity rarely exceeded tolerance thresholds (0.3125 S m(-1)) for bald cypress upstream but did so in some downstream areas. This provided an explanation for observed vegetation changes that both surface water and groundwater salinity failed to explain. The results offer a methodological and analytical framework for floodplain monitoring in locations where restoration success depends on vadose zone hydrology and provide relationships for evaluating proposed restoration and management scenarios for the Loxahatchee River.  相似文献   
723.
株洲高新区以长株潭(长沙市、株洲市、湘潭市)两型社会示范建设为契机,规划建设以低碳经济为主体产业的国家生态工业示范园区。株洲高新区在有色金属深加工、先进制造等行业的科研创新体系日趋完善,且产业集群初具规模,已具备了创建国家生态工业示范园区的有利条件。通过国家生态工业示范园区创建工作,将进一步优化区域产业结构,推动产业联动发展。园区建设总体上分为产业循环体系、污染控制体系和保障体系三部分。  相似文献   
724.

In this present study, adsorptive membranes for Cr(VI) ion removal were prepared by blending polyethersulfone (PES) with hydrous ferric oxide (HFO) nanoparticles (NPs). The effects of HFO NPs to PES weight ratio (0–1.5) on the physicochemical properties of the resultant HFO/PES adsorptive membranes were investigated with respect to the surface chemistry and roughness as well as structural morphologies using different analytical instruments. The adsorptive performance of the HFO NPs/PES membranes was studied via batch adsorption experiments under various conditions by varying solution pH, initial concentration of Cr(VI), and contact time. The results showed that the membrane made of HFO/PES at a weight ratio of 1.0 exhibited the highest adsorption capacity which is 13.5 mg/g. Isotherm and kinetic studies revealed that the mechanism is best fitted to the Langmuir model and pseudo-second-order model. For filtration of Cr(VI), the best promising membranes showed improved water flux (629.3 L/m2 h) with Cr(VI) ion removal of 75%. More importantly, the newly developed membrane maintained the Cr(VI) concentration below the maximum contamination level (MCL) for up to 9 h.

  相似文献   
725.
At present,water pollutant emission trading plays an increasingly important role in pollution control in many foreign countries,and its pilot studies and demonstration have also been started in China.In order to solve the problem of initial allocation of emission permits: premise and basis of emission trading in a river basin,basic principles on initial allocation of actual emission permits in China are put forward.And it is thought that local development stage of industry should be taken into full account for initial allocation model of emission permits.There are five different allocation models in different development stages of industry,including models like distribution according to needs,improved same-rate reduction,performance,integration and environmental capacity,etc.The initial allocation of emission permits in various basins should choose a suitable model in accordance with their respective development stages.It is suggested in this article that integrated allocation model should be a main choice for current development stage of industry in China.  相似文献   
726.
通过分析现代物流对生态工业园建设带来的环境影响,论述了在可持续发展原则下的绿色物流战略;并以苏州新加坡工业园为例,探讨了绿色物流的发展模式,以及这种模式对生态工业园建设的意义。  相似文献   
727.
稀土金属铈对湿式氧化催化剂性能的影响   总被引:15,自引:2,他引:13  
采用浸渍沉淀法制备具有相同cu负载量的CuO/7-Al2O3,CuO—CeO2/7-Al2O3和CuO-nO-CeO2/7-Al2O3催化剂,用H酸配水的催化湿式氧化评价催化剂的性能.结果表明,稀土元素Ce作为活性成分,不仅可以显著加快初期的反应速率,而且也增加了第二阶段的反应速率;还能提高反应中间产物小分子羧酸的降解速度和反应终了的pH值,从而减少金属铜的溶出;掺杂Ce使催化剂的晶体大小和孔隙分布更为均匀,孔径增大,有利于催化剂整体性能的改善.  相似文献   
728.
IntroductionThereisagrowingpublicconcernandscientificinterestsovertheheavymetalpollutioninagriculturalsoilsandagriculturalproductionsbecauseoftheirpotentialbioaccumulation ,responsehysteresis,andun biodegradability(Kelly,1996;Tam ,2 0 0 0 ;Hong,2 0 0 3)eventhoughthecontentsandspatialdistributionoftracemetalsintheagriculturalsoilsinGuangdonghaveneverbeenstudiedsystematically .Ingeneral,naturalbackgroundcontentanddistributionofheavymetalinsoilswerecloselyrelatedtothebiogeochemicalcycles,parentm…  相似文献   
729.
Although often overlooked, pets and other animals intersect with organizations in interesting, important ways. We seek to define how various animals intersect with organizations, highlight opportunities for theory development, and illustrate important areas for future research. We also explore how pandemics such as COVID-19 might affect the animals we highlight.  相似文献   
730.
Biodegradability enhancement of landfill leachate using air stripping followed by coagulation/ultrafiltration (UF) processes was introduced. The air stripping process obtained a removal efficiency of 88.6% for ammonia nitrogen (NH4–N) at air-to-liquid ratio of 3500 (pH 11) for stripping 18 h. The single coagulation process increased BOD/COD ratio by 0.089 with the FeCl3 dosage of 570 mg l?1 at pH 7.0, and the single UF process increased the BOD/COD ratio to 0.311 from 0.049. However, the combined process of coagulation/UF increased the BOD/COD ratio from 0.049 to 0.43, and the final biological oxygen demand (BOD), chemical oxygen demand (COD), NH4–N and colour of leachate were 1223.6 mg l?1, 2845.5 mg l?1, 145.1 mg l?1 and 2056.8, respectively, when 3 kDa molecular weight cut-off (MWCO) membrane was used at the operating pressure 0.7 MPa. In ultrafiltration process, the average solution flux (JV), concentration multiple (MC) and retention rate (R) for COD was 107.3 l m?2 h?1, 6.3% and 84.2%, respectively.  相似文献   
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