长江经济带总磷污染状况与对策建议

长江经济带是我国重要的战略区域,加强长江经济带生态环境保护是我国的重大战略部署,在推进我国"五位一体"总体布局建设中具有重要地位,是体现习近平总书记"共抓大保护,不搞大开发"的重要精髓。目前,总磷已成为长江经济带水体首要污染指标,总磷超Ⅲ类的断面比例达到18.3%,主要的一级支流中,沱江、清水江、岷江、乌江总磷平均浓度在地表水Ⅲ类水质标准上下浮动,污染相对较重;长江经济带总磷污染主要受工业、城镇生活、农业等污染源影响,主要涉及四川、贵州、湖北、湖南、重庆等地区;同时结合总磷污染特征分析,提出了涉磷工业企业治理、磷矿管理、城镇生活污水治理、畜禽养殖防治、规范监测方法等治理措施,为长江经济带总磷污染防控提供技术支撑和决策依据。     

“十二五”四川省主要污染物总量减排形势分析

实施污染物总量减排是我国环境管理和污染控制的重大举措,“十二五”期间仍将是我国环境保护的重点内容。本文根据四川省“十一五”总量减排的成效和问题,结合国家对“十二五”总量减排的新要求和特点,从畜禽养殖、城镇生活污染、机动车尾气防治、重点行业减排等方面,对未来减排存在的压力进行了分析,并由此提出了优化产业结构、严把项目准入关、加强环保基础设施建设和管理、加强机动车污染防治、加强畜禽污染治理、加强重点污染源治理、构建综合保障体系等措施和建议。     

Temporal and Spatial Trends in Nutrient and Sediment Loading to Lake Tahoe,California‐Nevada,USA

Since 1980, the Lake Tahoe Interagency Monitoring Program (LTIMP) has provided stream‐discharge and water quality data—nitrogen (N), phosphorus (P), and suspended sediment—at more than 20 stations in Lake Tahoe Basin streams. To characterize the temporal and spatial patterns in nutrient and sediment loading to the lake, and improve the usefulness of the program and the existing database, we have (1) identified and corrected for sources of bias in the water quality database; (2) generated synthetic datasets for sediments and nutrients, and resampled to compare the accuracy and precision of different load calculation models; (3) using the best models, recalculated total annual loads over the period of record; (4) regressed total loads against total annual and annual maximum daily discharge, and tested for time trends in the residuals; (5) compared loads for different forms of N and P; and (6) tested constituent loads against land use‐land cover (LULC) variables using multiple regression. The results show (1) N and P loads are dominated by organic N and particulate P; (2) there are significant long‐term downward trends in some constituent loads of some streams; and (3) anthropogenic impervious surface is the most important LULC variable influencing water quality in basin streams. Many of our recommendations for changes in water quality monitoring and load calculation methods have been adopted by the LTIMP.     

挥发性油藏回注气井控因素分析及措施

文章明确了挥发性油藏天然气回注井控的安全环保关键因素;量化了低渗挥发性油藏天然气回注注入能力,确定注入端各节点安全生产压力分布,攻关相关配套工艺设备,实现安全有效注入;开展室内实验和PVT相态拟合,分析注天然气后天然气和原油性质变化规律,创新非混相驱组分数值模拟参数优化方法,开展带人工压裂裂缝的组分数值模拟,精准确定压力场分布,降低计量及监测不准带来的安全隐患;明确注气井气窜影响因素,优化注采参数,抑制油井气窜,降低生产风险,实现井控安全情况下的天然气驱环保高效开发。     

总量控制区域排污权的初始分配方法

提出了区域排污权的初始分配方法该方法通过引入"平权函数"和"平权排污量"保证初始排污权分配的现实性和公平性;通过引入"有效环境容量"保证初始排污权分配与环境质量目标相一致作为简化实例,本方法应用于某区域SO₂排污权的初始分配,该区域包括3个子控制区、12种行业类型．分配结果合理可行。     

Sulfur-containing amino acid methionine as the precursor of volatile organic sulfur compounds in algea-induced black bloom

After the application of methionine, a progressive and significant increase occurred in five volatile organic sulfur compounds (VOSCs): methanethiol (MeSH), dimethyl sulfide (DMS), dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS) and dimethyl tetrasulfide (DMTeS). Even in the untreated control without a methionine addition, methionine and its catabolites (VOSCs, mainly DMDS) were found in considerable amounts that were high enough to account for the water’s offensive odor. However, blackening only occurred in two methionine-amended treatments. The VOSCs production was observed to precede black color development, and the reaching of a peak value for total VOSCs was often followed by water blackening. The presence of glucose stimulated the degradation of methionine while postponing the occurrence of the black color and inhibiting the production of VOSCs. In addition, DMDS was found to be the most abundant species produced after the addition of methionine alone, and DMTeS appeared to be the most important compound produced after the addition of methionine+glucose. These results suggest that methionine acted as an important precursor of the VOSCs in lakes suffering from algea-induced black bloom. The existence of glucose may change the transformation pathway of methionine into VOSCs to form larger molecular weight compounds, such as DMTS and DMTeS.     

中国区域环境绩效及波特假说的再检验

以二氧化碳为非期望产出,基于序列DEA的方向性距离函数、环境规制强度指数、Malmqulist-Luenberger指数,测度了1999~2010年中国30个省、市、自治区及东、中、西、东北四大区域的环境技术效率、环境规制成本及全要素生产率,并对四大区域的全要素生产率进行了波特假说的再检验.研究结果表明:区域间的环境技术效率呈现东-东北-中-西依次递减的演变格局;东北老工业基地的环境规制成本最高、西部地区最低;环境规制强度与全国及四大区域全要素生产率有显著的正相关性,这支持了波特假说的存在;技术进步效应的检验结果显示,只有中部区域支持波特假说的存在,西部区域检验结果表明碳排放的规制过高会对技术进步带来消极影响;环境技术效率变化效应的检验结果显示,全国及四大区域均支持波特假说的存在,碳排放规制强度的加强,会推动各地区在不同时期追赶最优生产前沿面的程度.     

Biofilm structure and its influence on clogging in drip irrigation emitters distributing reclaimed wastewater

Using reclaimed wastewater for crop irrigation is a practical alternative to discharge wastewater treatment plant effluents into surface waters.However,biofouling has been identified as a major contributor to emitter clogging in drip irrigation systems distributing reclaimed wastewater.Little is known about the biofilm structure and its influence on clogging in the drip emitter flow path.This study was first to investigate the microbial characteristics of mature biofilms present in the emitters and the effect of flow path structures on the biofilm microbial communities.The analysis of biofilm matrix structure using a scanning electron microscopy (SEM) revealed that particles in the matrix of the biofilm coupled extracellular polysaccharides (EPS) and formed sediment in the emitter flow path.Analysis of biofilm mass including protein,polysaccharide and phospholipid fatty acids (PLFAs) showed that emitter flow path style influenced biofilm community structure and diversity.The correlations of biofilm biomass and discharge reduction after 360 h irrigation were computed and suggest that PFLAs provide the best correlation coefficient.Comparatively,the emitter with the unsymmetrical dentate structure and shorter flow path (Emitter C) had the best anti-clogging capability.By optimizing the dentate structure,the internal flow pattern within the flow path could be enhanced as an important method to control the biofilm within emitter flow path.This study established electron microscope techniques and biochemical microbial analysis methods that may provide a framework for future emitter biofilm studies.     

岩溶地下河水中多环芳烃、脂肪酸分布特征及来源分析

为探究重庆青木关岩溶地下河水中多环芳烃(PAHs)和脂肪酸的含量组成、分布特征、来源及污染水平,2013年雨季和旱季分别于地下河中进行水样采集,并利用气相色谱-质谱联用仪(GC-MS)对水样中PAHs和脂肪酸的组分进行定量分析.结果表明,青木关地下河水中PAHs和脂肪酸的含量范围分别为77.3~702 ng·L~(-1)和3 302~45 254 ng·L~(-1).组成上,PAHs以2~3环为主,其比例高于90%,脂肪酸碳数范围为C10~C28,以饱和直链脂肪酸为主,其次为单不饱和脂肪酸.分布特征上,雨季:地下河水中各采样点PAHs的含量差异较小,脂肪酸的含量在入口、出露处和出口呈现依次降低的趋势,其中出露处和出口脂肪酸的含量较为接近;旱季:地下河水中PAHs含量在入口、出露处和出口呈现先降后升的趋势,脂肪酸含量在各采样点较为接近.总体上,地下河水中PAHs和脂肪酸的含量都表现为雨季显著高于旱季.来源分析表明,青木关地下河水中PAHs主要来源于该河流域煤和木材、农作物秸秆等生物质的燃烧;脂肪酸主要来自该河流域内硅藻、绿藻等水生藻类和细菌,其中以水生藻类的贡献占主导.地下河水受到PAHs中轻度污染,相对于旱季,雨季污染更严重.     

微生物对饮用水典型消毒副产物前体物的降解效能及其群落特征

相对于CF（氯仿）等C-DBPs（含碳消毒副产物）,DCAN（二氯乙腈）等N-DBPs（含氮消毒副产物）具有更高的毒性.控制DBPs（消毒副产物）的前体物是抑制DBPs产生的最有效方法之一.为考察微生物降解DBPs前体物对生成DBPs的影响,分别选取C-DBPs和N-DBPs的典型代表物CF和DCAN及其相应的典型前体物Tyr（酪氨酸）和Asp（天冬氨酸）为研究对象,采用微生物培养前体物的方式,探究微生物对典型前体物Tyr和Asp的降解效果及其对生成CF和DCAN的控制效果.结果表明:①Tyr和Asp两种前体物经微生物降解后,DOC（溶解性有机碳）的去除率分别为94.0%和85.6%,DON（溶解性有机氮）的去除率分别为69.0%和81.0%.②在前体物经微生物降解后的水样中,氯化或氯胺化消毒后生成CF和DCAN的量较降解前均大大减少.以Tyr为前体物,水样经微生物降解、氯化消毒后生成CF和DCAN的量分别降低了56.1%和89.5%,氯胺化消毒后生成CF的量降低了68.5%;以Asp为前体物,水样经微生物降解、氯化消毒后生成DCAN的量最高可降低99.9%,经微生物降解、氯胺化消毒后生成的CF可降低50.7%.③对水样中微生物菌群分析发现,在门水平上的菌群主要有变形菌门（Proteobacteria）、放线菌门（Actinobacteria）和拟杆菌门（Bacteroidetes）,在属水平上的菌属主要有伯克氏菌属（Burkholderia-paraburkholderia）、半角藻属（Haliangium）、分枝杆菌属（Mycobacterium）、沉积小杆菌属（Sediminibacterium）、norank_f_Chitinophagaceae和动胶菌属（Zoogloea）.研究显示,微生物降解对DBPs典型前体物Tyr和Asp的去除,以及对生成CF和DCAN的控制具有较大的潜力,变形菌和放线菌在降解DBPs前体物中起到了重要作用.