基于矿化垃圾的生态护岸强化脱氮基质的可行性研究

生态护岸是目前河、湖治理与修复过程中削减面源氮营养盐的重要措施之一。而筛选高效、低耗的生态护岸基质材料是其关键环节。通过优化复配矿化垃圾、沸石和砾石,研制一种基于矿化垃圾的新型强化脱氮生态护岸基质材料,并从其透水和持水性、抗剪、抗压和抗冲刷性、生态安全性、植被相容性和氮削减特性等方面对该材料进行了性能评定。结果表明:该新型基质材料的透水(渗透系数为1.31~2.55 cm/min)、持水(持水度为5.87%~8.02%)、抗剪(抗剪强度大于60 kPa)、抗压(抗压强度大于380 kPa)以及抗冲刷的性能均满足生态护岸基质材料的要求;发光细菌毒理实验证实其生态安全性;该材料适于护岸植被芦苇、鸢尾和麦冬的生长;具有优良的氮削减性能(氨氮和总氮的削减率分别为95%和70%)。静态经济评价表明,该材料具有明显的成本优势。该新型材料的研制对于生态护岸脱氮功能拓展以及解决河湖治理中面临的"氮超标"问题具有现实意义。     

Photodegradation of 17α-ethynylestradiol in dissolved humic substances solution: Kinetics, mechanism and estrogenicity variation

17α-Ethynylestradiol(EE2) in natural waters may cause adverse effects on organisms due to its high estrogenic potency. Laboratory studies were performed to study the effects of a local humic acid(LHA), fulvic acid(LFA) and Aldrich humic acid(AHA) on the photochemical behavior and estrogenic potency of EE2. Here photolytic experiments demonstrated that pure aqueous EE2 could undergo direct and self-sensitized photodegradation at a global rate of 0.0068 hr~(-1).Photodegradation rate of EE2 in 5.0 mg/L dissolved humic substances(DHS) was determined to be 0.0274, 0.0296 and 0.0254 hr~(-1) for LHA, LFA and AHA, respectively. Reactive oxygen species(ROS) and triplet dissolved humic substances(~3DHS*) scavenging experiments indicated that the promotion effect of DHS on EE2 photodegradation was mainly aroused by the reactions of HOU(35%–50%),~1O_2(10%) andDHS*(22%–34%). However, the photodegradation of EE2 could also be inhibited when DHS exceeded the threshold of 10 mg/L. Three hydroxylation products of EE2 were identified using GC–MS and their formation pathways were also proposed. In vitro estrogenicity tests showed that EE2 was transformed into chemicals without estrogenic potency. These findings could extend our knowledge on the photochemical behaviors of steroid estrogens in sunlit natural waters.     

南京市秋季细颗粒物及臭氧生成敏感性初探

为考察江苏省南部地区重点排放源对南京市秋季细颗粒物(PM_(2.5))的贡献率及O_3生成敏感性,采用强力法针对特定排放源及污染物设置不同的排放情景,利用化学传输模拟系统Models-3/Community Multi-scale Air Quality(CMAQ)分析模拟区域内不同情景下地表PM_(2.5)及O_3浓度变化。2012年10月,电厂、钢铁和水泥的污染物排放对南京市PM_(2.5)浓度的平均贡献率分别为6.0%、25.5%和15.9%,对国控站点的贡献率分别为7.2%、17.7%和16.2%。钢铁对下风向区域的地表PM_(2.5)浓度的影响显著高于电厂及水泥部门的排放。从不同情境下模拟O_3地表浓度变化结果看出,南京市城区及下风向区域的O_3浓度随VOC排放削减降低,随NO_x排放削减升高,因而判定南京市秋季O_3生成属于VOC控制区。     

水污染源在线监测比对中存在的问题研究

结合环境监测工作的实际情况,从评价标准体系、仪器性能指标和其它等3方面对中国污染源水质在线监测比对中存在的问题进行分析,建议质控样考核以标准品自身的不确定度为依据评判;考虑到实际水质的复杂性,实际水样比对相对误差统一设定为20%,同时取消低浓度质控样代替实际水样进行试验,引进新的实际水样考核指标,如标样加入试验、精密度试验等,让所有的实际水样考核数据都参与到最终的结果评估中.     

广东省春节期间空气质量特征及预报方法研究

2017年春节期间广东省环境空气质量自动监测站的数据分析结果表明:春节假期广东省空气质量等级变化较大.除夕全省空气质量为良;初一,全省以良和轻度污染为主,粤东出现重度污染,粤西和粤北出现中度污染,可能与除夕夜烟花爆竹燃放有关;初二起,全省空气质量逐渐转为优良.首要污染物以PM2.5和O3为主.现有的NAQPMS和CMAQ空气质量预报模型在污染相对严重的初一表现较差,主要是因为数值模型未能考虑到烟花爆竹燃放等排放源的输入.     

地形、树种和土壤属性对喀斯特山区土壤胞外酶活性的影响

土壤胞外酶在生态系统生物地球化学循环过程中扮演着重要角色,然而关于土壤胞外酶活性的主控因子研究还不够深入,特别是在偏碱性的钙质土壤区域相关研究尤其缺乏.本研究以典型喀斯特山区(木论国家级自然保护区)的林地为研究对象,采集不同地形条件(不同坡位和坡向)、不同树种(厚壳桂和伞花木)下的表层土壤(0~15 cm),测定了与碳、氮、磷循环相关的6种水解酶的活性及相关土壤理化性质.研究运用方差分解,并结合多响应置换过程以及冗余分析技术分析了地形、树种和土壤理化性质对土壤酶活性的影响.结果表明,坡位对土壤酶活性有显著影响.树种和坡向对土壤酶活性的影响不显著.方差分解结果表明,地形、树种和土壤理化性质共同解释了土壤酶活性变化的55.3%,其中土壤因子是影响酶活性改变的主要因子,解释了44.2%的变异.而冗余分析的结果进一步表明在土壤因子中,pH、总氮和无机氮是影响土壤酶活性变化的主要指标.研究首次量化了喀斯特地区小尺度内地形、树种及土壤理化性质对土壤酶活性变化的影响.研究也说明了在喀斯特山区小尺度内土壤酶活性的变化可由土壤理化性质来表征.     

非常规突发事件应急指挥组织结构研究

针对目前我国非常规突发事件应急响应过程中存在组织成员职责不明、关系不顺,难以实现快速联动和协同配合的问题,依据我国应急管理规章制度,以开放理性系统视角分析应急指挥组织结构(ECOS)的特点,基于组织理论提出契合行政级别的、具有闭环反馈的ECOS。以2010年夏三峡区域遭遇长江流域全流域性洪水为背景,基于提出的组织结构对三峡水库防洪应急指挥组织进行规范设置。研究结果表明,ECOS中各级政府应急部门采用官僚结构,现场指挥部采用项目小组结构,会商小组采用任务小组结构,整体构成矩阵结构。在稳定、理性、规范、高效的基础上,更具弹性和灵活性。这种刚性和柔性复合的、有层次和权威的、开放和权变的ECOS更适合我国国情以应对非常规突发事件。     

入库支流对贵州阿哈水库水体Fe和Mn的贡献率分析

游鱼河为贵州省阿哈湖水库典型煤矿酸性废水汇入支流,通过对游鱼河6月和8月分别连续24h的现场物理化学参数测试和样品实测分析,从水库水质安全方面探讨游鱼河铁、锰的变化特征及对水库水体铁、锰的贡献率.结果显示,游鱼河流域煤矿酸性废水通过投加石灰处理,pH值提高,符合排放要求,HCO3-碱度也有所增加,使水体具备一定缓冲性能.而SO42-质量浓度高于国家地表水环境质量标准,除6月铁符合标准,锰的超标率达到91.7％,8月铁、锰超标率分别为87.5％和100％.游鱼河入库水体中铁、锰按平均质量浓度分别为0.65 mg/L和0.98mg/L,每年进入阿哈湖水库中溶解态铁、锰分别为23.57 t和35.54 t,铁、锰来源与外来补水中铁、锰浓度及河流底泥中铁、锰释放有很大关系.     

Polybrominated diphenyl ethers (PBDEs) in the riverine and marine sediments of the Laizhou Bay area, North China

62 riverine and marine sediments were collected from the Laizhou Bay area, where the largest manufacturing base of brominated flame retardants (BFRs) in Asia is located. Eight polybrominated diphenyl ethers (PBDEs) were analyzed to investigate the impact of rapidly-developed bromine industries on the regional aquatic system. PBDE concentrations varied largely in riverine sediments. Σ(7)PBDEs (including BDE 28, 47, 99, 100, 153, 154 and 183) and BDE 209 ranged from 0.01 to 53 ng g(-1) dw and from 0.74 to 285 ng g(-1) dw with a mean value of 4.5 ng g(-1) dw and 54 ng g(-1) dw, respectively, indicating a strong influence of direct pollution discharges from local factories. In marine sediments, Σ(7)PBDEs and BDE 209 ranged from not detected (nd) to 0.66 ng g(-1) dw and from 0.66 to 12 ng g(-1) dw with a mean value of 0.32 ng g(-1) dw and 5.1 ng g(-1) dw, respectively. PBDE concentrations were mostly <10 ng g(-1) dw for Σ(7)PBDEs and <50 ng g(-1) dw for BDE 209, which are at a relatively low level for monitored riverine and coastal sediments around the world. Even at the most contaminated sites in Laizhou Bay area, PBDE concentrations were not among the highest concentrations reported in the literature. Congener compositions were dominated by BDE 209 (57.2-99.9% of the sum of BDE congeners), with minor contributions from penta- and octa-BDE products. Tri- to octa-BDE congeners were well correlated among each other (r > 0.75) and thus sources from similar mixing of penta- and octa-BDE products were suggested in this area. Compared with riverine sediments, a much better correlation between PBDE concentrations with TOC was observed in marine environment. The congener pattern changed and their correlation coefficients among each other were remarkably reduced. Contributions of BDE 28, 47 and 99 to Σ(7)PBDEs were generally the same in almost all the marine sites, while it was distinctively higher for BDE 153. These are probably attributable to several reasons, such as contributions by atmospheric deposition and/or redistribution between particles of various sizes during and/or after fluvial transportation combined with the difference of physiochemical properties of BDE congeners.