硝酸盐水质污染与污染源类型的相关性以及氮同位素的应用分析

为了研究莱芜市各类污染源对硝酸盐数值贡献的大小,通过莱芜市地下水污染调查项目各类污染源水质监测结果,挑选出符合对应污染源类型的硝酸盐水质监测数据,进行数理统计,显示对硝酸盐影响数值贡献最大的污染源类型为畜禽养殖,其次为农业面源污染、固体废弃物、工业废水排放、生活污水、矿坑排水。为识别莱芜市地下水中硝酸盐的来源,选取莱芜市10处同位素采样点进行δ¹⁵N及δ¹⁸O测试,根据测试结果,δ¹⁵N值变化范围为(5.82～19.95)×10^-3,δ¹⁸O值变化范围为(-8.76～-5.34)×10^-3,根据采样点δ¹⁵N、δ¹⁸O值所在的值域位置及所处的水文地质条件,表明10处同位素采样点处硝酸盐来源为粪便、化肥及工业污染,部分采样点的¹⁵N及δ¹⁸O的比值大于2,基本上可证明反硝化作用的存在。     

基于面源污染约束的玉米生产效率及其时空差异

采用基于非期望产出的非径向、非角度的数据包络分析模型测算了2006~2016年中国20个省份玉米生产效率并分析了其时空变化特征和影响因素。结果表明,东北区、黄淮海区和蒙新区玉米生产效率较高,但山东和辽宁效率值低于0.90,区内省际间差异较小;长江中下游区、西南区和西北区效率较低,但安徽、重庆、山西和甘肃效率值高于0.90,区内省际间差异较大。玉米生产效率总体上呈降低趋势,两极分化呈先缩小后扩大趋势,低效率地区数量显著增加。近3 a四川和贵州用工投入可缩减比例超过15%,辽宁化肥投入可缩减比例超过10%,吉林和黑龙江资本投入可缩减比例超过5%。总氮和总磷排放强度过高是各省份玉米生产效率降低的普遍原因,湖北、广西、贵州、云南和四川总氮可缩减比例达60%以上,宁夏、陕西和湖北总磷可缩减比例达50%以上。应通过水肥管理减少农田尺度肥料损失,通过布局调整和结构优化控制区域尺度肥料流失。东北区和黄淮海区应重点控制灌溉引起的磷肥排水损失和氮肥淋溶损失,西南区和长江中下游区重点控制暴雨径流引起的氮磷流失,西北区和蒙新区重点通过节水灌溉减少肥料流失。     

基于多尺度的中国环境污染事件时空分布及其影响因素

环境污染事件已成为人类社会发展面临的严峻挑战,严重制约着人类社会的可持续发展,当前急需厘清环境污染事件的时空特征及影响因素,为制定有效的环保政策提供借鉴。利用Theil指数、变异系数、ESDA等方法,分析了2006~2016年中国环境污染事件的时空分布特征,并借助地理探测器识别了不同尺度环境污染事件的影响因素。结果表明：① 2006~2016年省级尺度环境污染事件发生总频次与不同等级环境污染事件发生频次均呈波动下降趋势,其发生频次和区域差异呈“东-中-西”洼地型格局;② 地级市尺度环境污染事件发生频次随城市规模减小有所降低,随经济发展水平降低呈倒U型,同时,环保重点城市污染事件发生频次高于普通城市的特征;而环境污染事件的差异性表现为随城市规模减小有所降低,随经济发展水平降低而递减,及环保重点城市高于普通城市的特征。③ “胡焕庸线”以东地区环境污染事件多发且类型多样,以西地区污染事件少发且类型单一,不同等级环境污染事件的空间分布差异较大;④ 环境污染事件的影响因素存在差异,且随尺度增大,影响因素与环境污染事件的关联性趋于增强。其中,经济发展和环境监管水平对不同尺度环境污染事件均有显著影响,环境监管水平与其他因素的交互作用对不同尺度环境污染事件的解释力较高。     

废轮胎多孔隙消波结构物特性之初期研究

基于废旧轮胎再利用及研发简易且低廉的施工方法与维护成本,本研究以规则波水工模型试验研究提出应用于港口码头的多孔隙弹性帷幕的初步理念。利用模型车轮胎以模块化方式组装成弹性帷幕后安装于码头前壁,研究多种周期波浪作用及不同消波室纵深对波浪反射率的影响。实验结果表明,简单的单一消波室多孔隙弹性帷幕对短周期波浪的消波效果较显著,消波室纵深较大者反射率较低,但可能引致水体振荡,后续可再强化消波室的消能效果。未来如能妥善研究废旧轮胎应用于多孔隙弹性帷幕消波结构物的施工与维修方法,除可缓解废旧轮胎处理给环境带来的压力外,也提供一种可用于简易渔港的施工简单、维修容易且资源再利用的消能结构物,该工程技术亦可输出至发展中国家,符合可持续发展观。     

舟山海洋微塑料污染源头治理机制建设初探

海洋微塑料污染2004年才被英国科学家发现并提出,至今已经成为世界最受关注的生态环境问题之一。课题组认为公众是海洋微塑料污染的最主要源头。因此课题组立足舟山海域微塑料污染情况,包括塑料垃圾(资源)处理等情况,基于对公众认知的调查问卷,尝试描述以公众为核心、联合各行为主体的海洋微塑料污染源头治理机制,同时提出机制建立条件、困境与未来。此外,课题组关注社区、公益组织和市场的相应行为,力求在未来更为关注政府行为。     

Bacterial communities fluctuate in abundance and diversity under simulated oil-contaminated seawater conditions

Marine bacteria have recently been identified as a potent solution for petroleum hydrocarbon degradation in response to hazardous oceanic oil spills. In this study, a mesocosm experiment simulating a petroleum spill event was performed to investigate changes in the abundance, structure, and productivity of bacterial communities in response to oil pollution. Cultured heterotrophic bacteria and total bacteria showed a consistent trend involving an immediate decrease in abundance, followed by a slight increase, and a steady low-level thereafter. However, the changing trend of bacterial productivity based on bacterial biomass and bacterial volume showed the opposite trend. In addition, the density of oil-degrading bacteria increased initially, then subsequently declined. The change in the bacterial community structure at day 0 and day 28 were also analyzed by amplified ribosomal DNA restriction analysis (ARDRA), which indicated that the species diversity of the bacterial community changed greatly after oil pollution. Alphaproteobacteria (40.98%) replaced Epsilonproteobacteria (51.10%) as the most abundant class, and Gammaproteobacteria (38.80%) became the second most dominant class in the whole bacterial community. The bacterial communities in oil-contaminated seawater (32 genera) became much more complex than those found in the natural seawater sample (16 genera). The proportion of petroleum-degrading bacteria in the oil-contaminated seawater also increased. In this study, culture-dependent and culture-independent approaches were combined to elucidate changes in both bacterial productivity and community structure. These findings will contribute to a better understanding of the role that bacteria play in material cycling and degradation in response to oil pollution.     

土壤石油微生物降解影响因子的正交实验分析

利用微生物来降解土壤中的石油类污染物，是当前应用前景最好的土壤石油处理方法。多种因素同时制约着石油类污染物的生物降解。为了定量化各因素对彼此的影响，探求促进正向作用、抑制负向作用的途径，为各因素制定适宜的施用时间顺序以及施用量，以最大限度地加快降解速度，笔者设计了本文中的生物降解实验。结果表明，使用多因素复合处理方法可以在土壤石油处理中收到很好的效果；在实验的不同阶段，各影响因素的重要性及最优水平也会不同程度地变化。     

陆源污染生态损害评估及其补偿标准研究——以象山港为例

陆源污染是半封闭海湾环境恶化的主要原因,评估海湾地区陆源污染的生态损害,对目前迫切需要制定的海洋生态损害补偿政策以及生态修复计划具有重要的现实意义。本文以象山港为研究区域,运用生态恢复评估与生态服务价值评估相结合的方法,构建陆源污染生态损害评估模型,进行陆源污染对海湾生态服务损害评估与补偿标准研究。结果显示:(1)象山港陆源污染造成的生态服务损害价值为38 342.81万元,执行损害评估的费用约为20万元;以生态损害评估的总费用作为补偿标准,生态补偿费用共计38 362.81万元,单位面积补偿价值为0.42万元/hm~2·a。(2)象山港陆源污染所导致的海洋生态系统初始性修复成本为零,恢复期内损害价值主要以养分循环和净化环境为主,分别为19 740.72万元和13 938.13万元;美学景观损害价值为3 798.59万元,占比为9.91%;生物多样性维持损害价值598.66万元,占比为1.56%;食物生产的损害价值最小,为266.72万元。     

Investigation and evaluation of contamination in dredged reclaimed land in China

Large-scale reclamation projects have been developing rapidly in China’s coastal lands since 2000. In this study, the scale and pollutant contents of reclaimed lands were collected from published data and field surveys. Over 80% of the gross area was formed using hydraulic reclaimed technology. The pollution index, geoaccumulation index, and Nemerow integrated pollution index (NIPI) of 13 pollutant types were calculated based on the collected data. The potential pollution within major newly reclaimed lands was evaluated with valid pollutant data from sediments of the neighboring water. All reclaimed lands larger than 30?km² were slightly to seriously polluted with Cu, Pb, Zn, Cd, Cr, Hg, As, and Ni according to NIPI. The reclaimed fields in Hengsha Island, Binhai Tower, and Lingang New City of Shanghai were selected as verification sites for the pollution evaluations. The Cu, Pb, Zn, Cd, Cr, As, and Ni concentrations in dredged soils determined through inductively coupled plasma mass spectrometry showed a generally good soil quality within the typical reclaimed fields. Principal component and hierarchical clustering analyses indicated that the relatively high As content in the reclaimed soils was due to the internal pollutants of dredging fills and originated from anthropogenic sources.     

Occurrence and ingestion of microplastics by zooplankton in Kenya's marine environment: first documented evidence

Microplastics can be ingested by marine organisms and may lead to negative impacts at the base of marine food chains. This study investigated the occurrence and composition of microplastics in the sea-surface water and sought evidence of ingestion by zooplankton. Surface seawater was collected using a stainless-steel bucket and sieved directly through a stainless-steel sieve (250-µm mesh), while a 500-μm mesh net was towed horizontally to collect zooplankton, at 11 georeferenced stations off the Kenyan coast in February 2017, on board the national research vessel RV Mtafiti. Microplastic particles were sorted and characterised using an Optika dissecting microscope. Polymer types were identified using an ALPHA Platinum attenuated total reflection—Fourier-transform infrared (ATR-FTIR) spectrometer. A total of 149 microplastic particles, with an average abundance of 110 particles m^–3, were found in the surface seawater. A total of 129 particles were found ingested by zooplankton groups, where Chaetognatha, Copepoda, Amphipoda and fish larvae ingested 0.46, 0.33, 0.22 and 0.16 particles ind.^–1, respectively. Filaments dominated both the surface-water microplastics and the ingested microplastics, contributing 76% and 97% to those compositions, respectively. White particles were prevalent in the water (51%), whereas black was the colour found most commonly (42%) across the zooplankton groups. The sizes of particles that were in the water were in the range of 0.25–2.4 mm, and those ingested ranged between 0.01 and 1.6 mm. Polypropylene was predominant in the surface water, whereas low-density polyethylene was the most-ingested polymer type. The results provide the first documented evidence of the occurrence, composition and ingestion of microplastics by zooplankton in Kenya's marine environment, indicating that microplastics have the potential to enter pelagic food webs and cause pollution in the study area.