基于集成分析的环渤海地区河流硝酸盐污染解析

近几十年全球人口剧增,粮食生产及燃料消耗都增加了地表水中的氮负荷,而地表水是连接大陆氮库和海洋氮库的重要通道,地表水中的硝酸盐的增加将直接导致河口及沿海硝酸盐浓度的增加,因此研究近海河流的氮污染情况、确定影响因素将会为近海营养物质的控制及水环境管理提供重要信息.以环渤海地区的入海河流为主要研究对象,通过收集公开数据建立环渤海地表水硝酸盐数据库集成分析,研究入海河流的水体硝酸盐的时空污染特征及其与各影响因素之间的关系.结果表明,环渤海区域地表水中硝酸盐浓度的变化范围在0.0~76.4 mg·L~(-1),与溶解氧、总氮、总磷和电导率有显著的相关关系(p=0.01).在空间变化方面,黄河下游及浑太河上游流域硝酸盐污染较为严重.在除去来自城市污废水排放的人工河道带来的硝酸盐浓度异常值后,丰水期(平均浓度4.55 mg·L~(-1))与平水期(平均浓度5.39 mg·L~(-1))的硝酸盐浓度的平均水平较枯水期(平均浓度4.03 mg·L~(-1))更高,且浓度的变化范围(丰水期:0.00~34.90 mg·L~(-1);平水期:0.00~31.00 mg·L~(-1))亦大于枯水期(0.00~25.64 mg·L~(-1)).影响因素方面,硝酸盐浓度与降水量有显著相关性(r=0.122,p=0.01).土地利用相关性研究表明耕地与建设用地是硝酸盐的主要来源,林地和草地对硝酸盐污染有改善作用.硝酸盐的入海通量约为33.4×10~4t·a-1.     

泉州市大气PM2.5中有毒金属元素的环境风险评价

于2014年3月至2015年1月采集了泉州市5个采样点共136个PM_2.5样品, 采用电感耦合等离子体质谱仪（ICP-MS）测定样品中11种有毒微量金属元素（Zn、Cu、Pb、As、Ni、Cd、Co、Ba、Cr、Be、V）的浓度。采用单级酸提取法分析了大气PM_2.5中有毒金属元素的化学形态,并利用元素酸提态含量占总量的比值计算了有毒金属元素的生物有效性。采用美国EPA推荐的人体健康风险评估模型对大气PM_2.5中有毒金属元素的人体健康风险进行了评价。结果表明：（1）各有毒金属元素生物有效性大小顺序为Zn > Cu > Pb > As≈Ni > Cd > Co≈Ba > Cr > Be > V;（2）大气PM_2.5中Ni、As、Cd、Zn、Cu和Pb为生物可利用元素,容易在环境介质中进行迁移和转化;Be、Cr、Co、V和Ba为潜在的生物可利用元素,在大气环境中较为稳定,但当大气环境条件发生变化时有可能会重新被释放出来;（3）泉州市大气PM_2.5中有毒金属元素主要通过口鼻吸入方式危害人体健康,Cr、Co、As对泉州市区居民有潜在的致癌风险,Ni和As有潜在的非致癌风险。     

环境水污染事件应急监测演练评估模型构建研究

以环境水污染事件为背景,基于层次分析-线性加权法的构建环境水污染事件应急监测演练评估模型。利用层次分析法建立应急演练评估指标体系,构建各因素的判断矩阵,判断矩阵的特征向量作为评估指标的权重,由多位专家评估的权重值计算平均权重,然后利用线性加权法构建应急演练的综合评估模型。通过某江河的水污染事件应急演练实例,对评估模型进行了验证。     

基于系统投入产出和生态网络分析的能源-水耦合关系与协同管理研究——以湖北省为例

能源和水资源之间存在紧密的耦合关系。以往的资源管理政策往往只关注单一资源,忽略了两者的关联性。为促进能源和水资源综合管理,有必要开展能源-水耦合关系和协同管理研究。从社会经济网络视角出发,论文综合运用系统投入产出和生态网络分析方法,构建了湖北省2007和2012年能源-水耦合网络核算框架。结果表明：1）2012年湖北体现能源最终消费量为14 304.93万tce,体现水资源最终消费量为346.66亿m³,相比2007年分别增长52.26%和7.89%,其中,体现在最终使用中能源与水资源流有近50%来自制造业;2）2007年湖北省水资源网络和能源网络的循环率都约为2.71%,与2007年相比,2012年水资源网络循环率显著增长至4.23%~4.40%,而能源网络循环率则变化较小;3）能源网络和水资源网络的系统鲁棒性都偏向于冗余度更高、效率更低的一侧;4）由于能源-水耦合网络的引入,2007—2012年间,在能源和水资源网络中,电力、热力生产和供应部门对于大多数部门的控制都呈现不同程度的增强趋势。研究辨识了能源与水资源协同管理的关键部门和路径,为湖北省能源和水资源可持续利用提供了理论与数据支撑。     

Relating Cd2 + binding by humic acids to molecular weight: A modeling and spectroscopic study

Molecular weight(Mw) is a fundamental property of humic acids(HAs), which considerably affect the mobility and speciation of heavy metals in the environment. In this study, soil humic acid(HA) extracted from Jinyun Mountain, Chongqing was ultra-filtered into four fractions according to the molecular weight, and their properties were characterized.Complexation of cadmium was investigated by titration experiments. For the first time,Langmuir and non-ideal competitive adsorption-Donna(NICA-Donnan) models combined with fluorescence excitation-emission matrix(EEM) quenching were employed to elucidate the binding characteristics of individual Mw fractions of HA. The results showed that the concentration of acidic functional groups decreased with increasing Mw, especially the phenolic groups. The humification degree and aliphaticity increased with increasing Mw as indicated by elemental composition analysis and FT-IR spectra. The binding capacity of Cd~(2+) to Mw fractions of HA followed the order UF1( 5 kDa) UF2(5–10 kDa) UF4( 30 kDa) UF3(10–30 kDa). Moreover, the distribution of cadmium speciation indicated that the phenolic groups were responsible for the variations in binding of Cd~(2+) among different Mw fractions. The results of fluorescence quenching illustrated that the binding capacity of Cd~(2+) to Mw fractions was controlled by the content of functional groups, while the binding affinity was largely influenced by structural factors. The results provide a better understanding of the roles that different HA Mw fractions play in heavy metal binding,which has important implications in the control of heavy metal migration and bio-toxicity.     

重庆市渝中区臭氧时空变化规律因素分析研究

臭氧是城市光化学烟雾的主要成分,同时也是重要的温室气体,因此臭氧污染已经成为城市空气质量的重要因素.对重庆市渝中区2015年3个空气质量自动监测点臭氧浓度进行比较,并分析了臭氧与环境、日照、气温、挥发性有机物、NO2、PM10、PM2.5的相关性.结果表明:臭氧浓度与监测点周围环境有关;臭氧浓度呈典型的季节变化趋势,与日照、气温呈明显的正相关;臭氧浓度小时值变化出现明显的日变化规律;臭氧浓度与挥发性有机物呈正相关,与NO2、PM10、PM2.5有较好的负相关性.     

中国矿业大学南湖校区噪声污染等级监测研究

以中国矿业大学南湖校区为例,采用分功能区监测布点的方法对校园各功能区人群密集地点的噪声污染等级进行监测和分析,以探明大学校园内各功能区人员密集时噪声所能达到的最大声级,并进行评价分析.结果表明:在人流密集状态下,校园内的各测点噪声等级均在60dB以上,处于噪声超限状态.故虽然校园内各测点全天的等效声级不超限或基本达到《声环境质量标准》(GB 3096-2008)的要求,但实质上校园声环境却时常处于"亚健康"状态.     

Anaerobic digestion in mesophilic and room temperature conditions: Digestion performance and soil-borne pathogen survival

Tomato plant waste(TPW) was used as the feedstock of a batch anaerobic reactor to evaluate the effect of anaerobic digestion on Ralstonia solanacearum and Phytophthora capsici survival. Batch experiments were carried out for TS(total solid) concentrations of 2%, 4% and 6% respectively, at mesophilic(37 ± 1°C) and room(20–25°C) temperatures. Results showed that higher digestion performance was achieved under mesophilic digestion temperature and lower TS concentration conditions. The biogas production ranged from 71 to 416 L/kg VS(volatile solids). The inactivation of anaerobic digestion tended to increase as digestion performance improved. The maximum log copies reduction of R. solanacearum and P. capsici detected by quantitative PCR(polymerase chain reaction) were 3.80 and 4.08 respectively in reactors with 4% TS concentration at mesophilic temperatures. However, both in mesophilic and room temperature conditions, the lowest reduction of R. solanacearum was found in the reactors with 6% TS concentration, which possessed the highest VFA(volatile fatty acid) concentration. These findings indicated that simple accumulation of VFAs failed to restrain R. solanacearum effectively, although the VFAs were considered poisonous. P. capsici was nearly completely dead under all conditions. Based on the digestion performance and the pathogen survival rate, a model was established to evaluate the digestate biosafety.     

Best Poster Award

正The folloing works were presented at the 5th Sino-French Joint Workshop on Atmospheric Environment:Air Quality Improvement and Future Challenges:Sciences,TechnologiesSolutions on October 11-14,2016.They received the Best Poster Awards that were sponsored by the Journal of Environmental Sciences.     

Characteristics of change in water quality along reclaimed water intake area of the Chaobai River in Beijing, China

To reveal the basic characteristics and controlling factors of water quality change in the project Wenyu to Chaobai reclaimed water diversion, the water quality in the study area was monitored for one year at seven monitoring sites. Inverse geochemical models of the statistical groups were developed using PHREEQC to elucidate the hydrochemistry characteristics of reclaimed water and the factors. The monitoring results indicated that nitrogen and phosphorus contents were significantly reduced along the river mainly caused by seasonal and location variation. The pH ranged from 7.44 to 9.81. Photosynthesis of algae and denitrification in anaerobic microenvironment ultimately led to a sudden p H increase after the Jian River and the Chaobai River confluence. Mg~(2+)and SO_4~(2-) levels dropped obviously in the summer and increased in winter seasons after intersection. Na+and Cl-are relatively stable, and marked drop in the concentration only after the two rivers meet. And there is a decrease of Ca~(2+) and HCO~(3-) and increase in CO_3~(2-) during monitoring period. As a whole, the primary ions and nutrient components, including nitrogen and phosphorus, had high levels in winter. Algae's photosynthesis and respiration were observed to have an impact on the river water quality; there was precipitation–dissolution of minerals and denitrification from upstream to downstream. Inverse geochemical PHREEQC modeling confirmed that there was precipitation of aragonite or calcite, and gypsum or anhydrite in summer, and dissolution in winter; as well as precipitation of dolomite in winter, and cationic exchange and denitrification along the river.