基于δ15N和δ18O的农业区地下河硝酸盐污染来源

为研究岩溶区农业活动为主导的地下河流域硝酸盐污染来源,于2017年5~10月每24 d左右对重庆青木关流域6个采样点进行监测,利用~(15)N和~(18)O同位素技术对示踪硝酸盐来源进行解译,应用IsoSource模型计算出不同端元硝酸盐的贡献率.结果表明:(1)青木关农业区地下河系统存在较大的硝酸盐污染风险,大部分采样点出现不同程度NO_3~--N浓度超标现象.(2)空间上,青木关地下河中NO_3~--N浓度整体呈现由上游向下游升高的趋势.时间上,上游鱼塘和岩口落水洞以及下游姜家泉样点NO_3~--N浓度在5~6月因受农业施肥的影响,均呈上升趋势,6~9月受降水影响而出现不同程度升高或降低,9月之后随着农业活动减少而逐渐降低;中游土壤点NO_3~--N浓度保持较高值;中下游大鹿池NO_3~--N浓度较低且变幅不大.(3)通过硝酸盐~(15)N和~(18)O同位素分析,表明上游鱼塘和岩口落水洞的硝酸盐源于土壤有机氮、动物粪便及污废水混合;中游土壤点硝酸盐源于土壤有机氮、降水和肥料中NH_4~+;中下游大鹿池中硝酸盐来源于动物粪便及污废水、土壤有机氮、降水和肥料中NH_4~+的混合作用.地下河出口处姜家泉硝酸盐污染严重,其源于土壤有机氮、降水和肥料中NH_4~+、动物粪便及污废水、大气沉降的综合作用.(4)基于IsoSource模型对地下河出口处硝酸盐来源进行定量分析,发现动物粪便及污废水贡献率占46.4%,土壤有机氮占32.6%,降水与肥料中NH_4~+占18.6%,大气沉降仅占2.4%.     

Emission characteristics of offshore fishing ships in the Yellow Bo Sea, China

Maritime transport has been playing a decisive role in global trade. Its contribution to the air pollution of the sea and coastal areas has been widely recognized. The air pollutant emission inventories of several harbors in China have already been established. However,the emission factors of local ships have not been addressed comprehensively, and thus are lacking from the emission inventories. In this study, on-board emission tests of eight diesel-powered offshore fishing ships were conducted near the coastal region of the northern Yellow Bo Sea fishing ground of Dalian, China. Results show that large amounts of fine particles( 0.5 μm, 90%) were found in maneuvering mode, which were about five times higher than those during cruise mode. Emission rates as well as emission factors based on both distance and fuel were determined during the cruise and maneuvering modes(including departure and arrival). Average emission rates and distance-based emission factors of CO, HC and PM were much higher during the maneuvering mode as compared with the cruise mode. However, the average emission rate of Nitrous Oxide(NOx) was higher during the cruise mode as compared with the maneuvering modes. On the contrary, the average distance-based emission factors of NOxwere lower during the cruise mode relative to the maneuvering mode due to the low sailing speed of the latter.     

Effect of phosphate releasing in activated sludge on phosphorus removal from municipal wastewater

Aluminum and ferric salts are commonly used in municipal wastewater treatment plants(WWPTs) for phosphorus(P) removal. In this study, on-site jar tests were conducted to determine the removal of different P species from the fresh samples in the presence and absence of activated sludge(AS) with different doses of alum, poly-aluminum chloride,and ferric chloride at different p H. The soluble P(SP) concentration in the samples was about 0.63 mg/L. When the mixed liquor containing AS was treated with 8 mg/L of Al, SP could be reduced to 0.13 mg/L, while it was reduced to 0.16 mg/L with only 1 mg/L of Al after sedimentation removal of AS from sample. Chemical analysis determined that AS contained 59.8 mg-P/g-TSS and 43.8 mg-Al/g-TSS and most of the P was associated with the aluminum hydroxide. We discovered that the phosphate in the AS could readily be released from it, which was mainly responsible for ineffective removal of P to low levels in mixed liquor even with very high alum dose. This study provides new insight into the behavior and fate of P in the wastewater treatment plants that use alum to enhance P removal in the final effluent.     

电化学方法用于酸性红B模拟废水脱色试验研究

本文研究了两种电极材料 (SnO2 Ti和RuO2 Ti)对酸性红B模拟废水的脱色效果 ,考察了不同 pH、电流密度(j)及外加电解质 (Na2 SO4/NaCl)对处理过程的影响。结果表明 ,两种电极材料都能对酸性红B染料废水进行有效脱色 ,主要是Cl-在电解过程中的间接氧化作用 ,同时也包括电极表面的直接氧化作用。     

森林防火性能化设计方法

根据消防工程、森林防火的原理和方法，参照建筑防火性能化设计方法，结合我国的森林防火现状，提出了森林防火性能化设计方法。将性能化设计理念融人到森林防火设计中有利于提高我国的林火管理水平。     

决策支持系统应用于城市环境管理

南宁市环境决策支持系统集环境管理办公自动化、环境管理系统(MIS)、环境地理信息系统(GIS)、多媒体环境管理信息应用和环境管理信息辅助决策等多功能一体集成的综合性环境信息系统，为南宁市环境管理、经济发展决策提供环境信息支撑与服务。     

Applying the methods of image evaluation and spatial analysis to study the sound environment of urban street areas

One important aspect of the urban environment is its sound environment, in which the sound environment of street areas plays a significant role. In this research, we employed methods of subjective image evaluation and spatial analysis of soundscape formation, in studying the sound environments of urban street areas. In Saga City, Japan, we analysed the structure and main sound components of urban street areas, as well as the sound pressure levels through on-site investigation. Through image evaluation, we obtained people's ratings of each sound component in terms of “preference” and “congruence”. Simultaneously, we interviewed people on site for their evaluation of the sound environment using semantic differential profiles. Lastly, we performed a spatial analysis of the site, identifying the different types of street sound environment and their characteristics using cluster analysis, as well as noting the interaction of auditory image and visual factors. The methods presented by this research can help us understand the sound environment of urban street areas more comprehensively and vividly, and to point out a unique direction in the research of urban sound environment as well as the planning of urban street areas.     

A COMPARISON OF SIX POTENTIAL EVAPOTRANSPIRATION METHODS FOR REGIONAL USE IN THE SOUTHEASTERN UNITED STATES1

ABSTRACT: Potential evapotranspiration (PET) is an important index of hydrologic budgets at different spatial scales and is a critical variable for understanding regional biological processes. It is often an important variable in estimating actual evapotranspiration (AET) in rainfall‐runoff and ecosystem modeling. However, PET is defined in different ways in the literature and quantitative estimation of PET with existing mathematical formulas produces inconsistent results. The objectives of this study are to contrast six commonly used PET methods and quantify the long term annual PET across a physiographic gradient of 36 forested watersheds in the southeastern United States. Three temperature based (Thornthwaite, Hamon, and Hargreaves‐Samani) and three radiation based (Turc, Makkink, and Priestley‐Taylor) PET methods are compared. Long term water balances (precipitation, streamflow, and AET) for 36 forest dominated watersheds from 0.25 to 8213 km² in size were estimated using associated hydrometeorological and land use databases. The study found that PET values calculated from the six methods were highly correlated (Pearson Correlation Coefficient 0.85 to 1.00). Multivariate statistical tests, however, showed that PET values from different methods were significantly different from each other. Greater differences were found among the temperature based PET methods than radiation based PET methods. In general, the Priestley‐Taylor, Turc, and Hamon methods performed better than the other PET methods. Based on the criteria of availability of input data and correlations with AET values, the Priestley‐Taylor, Turc, and Hamon methods are recommended for regional applications in the southeastern United States.     

德国工伤保险的特点及成功之处(上)

德国是世界上第一个建立工伤保险制度的国家。1884年7月6日,德国颁布工伤保险法,其基于与民法不同的原则,即“不以追究事故责任者确定赔付的原则”。其含义为,在工伤赔付上,无需再追究是雇主还是雇员方面的过错,而是以是否发生在就业过程中为确定工伤赔付范围的划定标准。工伤保险法律将过去由工人方面承担事故后果,转移向由雇主方面承担。但雇主的责任不是以企业主个人承担     

马来西亚职业安全与卫生联合信息系统

法律法规马来西亚的新《职业安全与卫生法》是1994年颁布的。该法修订了1967年颁布的《工厂与机器法》。《工厂与机器法》是先前制订颁布的《职业安全与卫生法》的一个主要篇章,它在一些特定的机械作业、建筑以及一些工程特定的伤害细节上没有规定要提供充分的防护。因此1994年的《职业安全与卫生法》明确体现了全面关注全国劳工安全、卫生与福利的立法意图。