PM2.5中类腐殖质表面活性测定方法与实例分析

建立了大气细粒子中类腐殖质（HULIS）表面活性的动态表征方法,并以华北平原乡村站点冬季大气PM_2.5样品为例,对PM_2.5中HULIS的表面活性进行表征.HULIS碳质组分（HULIS-C）浓度为2.0~4.6μg C/m³,占水溶性有机碳和总有机碳的比例分别为31%~40%和20%~26%.浓度为88~200mg C/L的HULIS水溶液,其表面张力相对于纯水降低了18%~22%.HULIS-C浓度在低于70mg C/L时表面张力降低显著,在88~320mg C/L之间降低相对缓慢.动态表面张力随着时间变化逐渐降低,在液滴形成后200s以内表面张力下降迅速,之后趋于平缓,说明表面活性分子在液滴中扩散趋于稳定需要一定的时间,该特征时间可能影响表面活性物质在云凝结核活化时的作用.证实了在污染地区的大气PM_2.5中含有一定量的表面活性物质,这些物质可能对颗粒物活化为云滴、雾滴过程产生显著影响;表面活性物质的存在可能在外界湿度变化过程中导致颗粒物发生液-液相分离现象,在颗粒物表面形成有机膜,影响活性分子摄取以及半挥发性物质的气-粒分配过程,从而影响大气非均相反应过程.     

农村生活污水处理设施优先控制区域识别与监管策略

选取嘉兴市秀洲区和海宁市为研究对象,以乡镇区划为研究单元,采用综合源强估算法和GIS软件,对处理设施的氨氮（NH₃-N）、总磷（TP）、化学需氧量（COD）排放强度进行定量估算和空间分析.结果表明,秀洲区处理设施的NH₃-N和COD排放强度高于海宁市,而TP排放强度与海宁市差不多.秀洲区内,洪合镇各污染物的排放强度均最高;海宁市内,盐官镇NH₃-N排放强度最高,许村镇TP和COD排放强度最高.采用因子分析法和加权指数法计算排污权重,再结合生态敏感性评价和环境功能区划,筛选出运维和监管优先控制区.秀洲区内,洪合镇、王江泾镇、油车港镇被划分为优先控制区,该优先控制区内处理设施数量占比27.87%,排污权重占比72.42%,通过重点监管17.66%的设施,可监管秀洲区59.98%的污染物排放.海宁市内,长安镇、许村镇、海洲街道、盐官镇、袁花镇被划分为优先控制区,该优先控制区内设施数量占比69.10%,排污权重占比71.23%,通过重点监管16.85%的设施,可监管海宁市43.54%的污染物排放.研究结果可为提高设施的运维监管效率提供技术支撑.     

Effect of manganese oxide-modified biochar addition on methane production and heavy metal speciation during the anaerobic digestion of sewage sludge

Low organic matter content and high heavy metal levels severely inhibit the anaerobic digestion (AD) of sewage sludge. In this study, the effect of added manganese oxide-modified biochar composite (MBC) on methane production and heavy metal fractionation during sewage sludge AD was examined. The MBC could increase the buffering capacity, enhance the methane production and degradation of intermediate acids, buffer the pH of the culture, and stabilize the sewage sludge AD process. The application of MBC positively impacted methane production and the cumulative methane yield increased up to 121.97%, as compared with the control. The MBC addition can improve metal stabilization in the digestate. An optimum MBC dose of 2.36?g was recommended, which would produce up to 121.1?L/kg volatile solids of methane. After the AD process, even though most of the metals accumulated in the residual solids, they could be transformation from the bio-available fractions to a more stable fraction. The total organic- and sulfide-bound and residual fraction content at a 3?g dose of MBC that is 0.12?g/g dry matter were 51.06% and 35.11% higher than the control, respectively. The results indicated that the application of MBC could improve the performance of AD and promote stabilization of heavy metals in sewage sludge post the AD process.     

Morphology and composition of particles emitted from a port fuel injection gasoline vehicle under real-world driving test cycles

Traffic vehicles, many of which are powered by port fuel injection (PFI) engines, are major sources of particulate matter in the urban atmosphere. We studied particles from the emission of a commercial PFI-engine vehicle when it was running under the states of cold start, hot start, hot stabilized running, idle and acceleration, using a transmission electron microscope and an energy-dispersive X-ray detector. Results showed that the particles were mainly composed of organic, soot, and Ca-rich particles, with a small amount of S-rich and metal-containing particles, and displayed a unimodal size distribution with the peak at 600?nm. The emissions were highest under the cold start running state, followed by the hot start, hot stabilized, acceleration, and idle running states. Organic particles under the hot start and hot stabilized running states were higher than those of other running states. Soot particles were highest under the cold start running state. Under the idle running state, the relative number fraction of Ca-rich particles was high although their absolute number was low. These results indicate that PFI-engine vehicles emit substantial primary particles, which favor the formation of secondary aerosols via providing reaction sites and reaction catalysts, as well as supplying soot, organic, mineral and metal particles in the size range of the accumulation mode. In addition, the contents of Ca, P, and Zn in organic particles may serve as fingerprints for source apportionment of particles from PFI-engine vehicles.     

典型肥料生产场地氨氮分布特征及风险控制目标确定

为探究肥料生产场地的NH₃-N（氨氮）分布特征及环境风险,以我国某肥料生产场地为研究对象,在场地调查基础上,对场地土壤和地下水NH₃-N的空间分布进行分析,并以人体健康和场地地下水为保护对象分别讨论了土壤NH₃-N风险控制目标值的计算方法.结果表明:①目标场地土壤中w（NH₃-N）为0.03~15 000 mg/kg,水平方向上高值区集中分布于核心生产区及原辅料堆场,垂向上总体表现为由上至下随深度增加呈先逐步升高后降低的趋势,并且富集于人工填土与原状粉质黏土交界处,粉质黏土阻碍NH₃-N向下迁移,并随地层结构变化其迁移深度不同.②场地上层滞水和潜水中ρ（NH₃-N）分别为19.10~3 320和0.03~219 mg/L,超标率分别为100%和57.89%,并且地下水与土壤的NH₃-N在水平空间分布上具有重叠特征.③因NH₃-N主要通过呼吸吸入挥发性气体产生暴露,并且仅有经呼吸暴露的毒性参数,故采用《污染场地风险评估技术导则》中经呼吸暴露途径的非致癌效应风险控制值计算模型来计算土壤NH₃-N的控制目标,通过代入场地实测土壤K_d（土-水分配系数）,得到居住用地下的土壤NH₃-N控制目标值为9 195 mg/kg;若考虑保护地下水水质安全,据三相或两相平衡模型耦合NH₃-N在包气带衰减和地下水稀释作用,当目标场地地表无积水的入渗条件下得到的控制目标值为6 203 mg/kg;当地层从上至下呈饱和含水条件时,土壤NH₃-N控制目标为811 mg/kg.计算值可用作不同场地进行土壤NH₃-N风险管控的参考目标,实际应用中可结合不同地块环境条件、不同受体和保护目标,选择相应的风险控制值对场地进行风险管控.此外,土壤和地下水的NH₃-N污染控制均可考虑采用工程措施和制度控制来进行.      

1995-2015年江苏省土地利用功能转型特征及其协调性分析

土地利用功能转型可实现土地利用功能协调,是实施区域可持续发展的重要路径。从功能协调角度构建土地利用功能转型分析框架,利用江苏省1995年、2000年、2005年、2010年和2015年5期遥感影像及相关资源利用和社会经济数据,构建三级土地利用功能评价体系,以县域为评价单元,通过三角模型和空间相关分析等方法,定量解析江苏省土地利用功能时空演变特征及其与土地可持续利用目标的协调状况。研究结果显示：（1）研究期内,江苏省土地利用功能总水平提升减慢,其中生产、生活功能不同程度提升,生态功能明显下降。（2）生产、生活功能空间集聚不突出,生态功能的热点、冷点区域呈“Y”型集聚分布。（3）不同功能区功能协调性态势不一,重点开发区和限制开发区可持续发展态势总体良好,优化开发区可持续发展程度较弱并持续恶化。建议江苏省在落实发展蓝图和空间规划的过程中,应优先推进苏南现代化示范区建设,重点实施重点开发区生活功能转型、Ⅰ类限制开发区生产功能转型策略,并严格落实禁止开发区的生态保护责任等差别化管理策略。     

城市不同源雾霾颗粒物健康风险差异评估比较

通过研究不同来源霾颗粒物对大鼠气管上皮细胞（RTE cells）电阻抗变化和细胞自噬因子的影响,评价不同来源霾颗粒物对人体健康风险的差异性.分别将RTE暴露于从居民区（I）,高架交通源（Ⅱ）和化工园区（Ⅲ）采集的3种雾霾颗粒物中,统一暴露浓度和时间分别为100mg/L和24h.通过电子细胞基质阻抗检测（ECIS）细胞增长引起的阻抗变化和细胞电损伤恢复时间;通过蛋白免疫印迹测定p62,Atg5,Atg7,Beclin1,LC3B和mTOR蛋白表达量来分析比较不同来源雾霾颗粒物对RTE细胞自噬的影响.结果表明,与空白对照组相比,不同雾霾颗粒物处理组细胞电损伤恢复时间分别延长了34.6%,63.2%和78.0%;p62蛋白表达量差异显著性下降,Atg5,Atg7,Beclin1,LC3B蛋白表达量差异显著性上升.此外,mTOR相关蛋白表达量差异显著性下降,分别下降了4.38%,3.34%和2.36%;p-mTOR蛋白表达量与空白组相比,实验组I下降24.2%,实验组Ⅱ下降37.0%,实验组Ⅲ下降60.9%.由以上结果可知,不同来源雾霾颗粒物对RTE细胞均有一定的毒性损伤作用,能够减小细胞增长速度和削弱细胞修复能力,增强细胞自噬因子蛋白的表达,且化工园区采集的雾霾颗粒物毒性强于居民区和高架交通源.不同来源雾霾颗粒物的细胞毒性存在明显差异,基于细胞电损伤恢复时间的测定以及自噬相关蛋白的检测方法能够为雾霾颗粒物健康风险评价提供一种快速的生物学手段.     

阳澄湖沉积物重金属空间分布及生物毒害特征

为了解阳澄湖沉积物重金属含量空间分布及污染特征,选取阳澄湖柱状沉积物样为研究对象,采用电感耦合等离子体质谱仪（ICP-MS）、原子荧光光谱仪（AFS）和Hydra-c型全自动测汞仪于2018年2月对阳澄湖15个采样点沉积物柱状样中8种重金属Cr、Ni、Cu、Zn、As、Cd、Pb、Hg进行测定,分析重金属元素含量在水平及垂向的分布特征和污染状况.结果表明,阳澄湖表层沉积物中Cr、Ni、Cu、Zn、As、Cd、Pb、Hg平均含量分别为101.28,68.72,66.54,187.33,15.85,0.45,34.02,0.09mg/kg,是各自背景值的1.34,2.09,2.89,2.88,1.69,4.99,1.54,3.00倍.垂向上重金属的含量随着深度的增加呈现出下降的趋势.对8种重金属进行相关分析和聚类分析,除As、Ni和Hg外,不同重金属之间存在着显著相关关系（P<0.05）,这说明阳澄湖沉积物重金属之间存在着一定的同源性.采用沉积物质量基准（SQG）对阳澄湖沉积物中重金属生物毒性效应进行了评价,结果表明,阳澄湖沉积物中Ni有75%以上的可能性出现生物毒害效应,Cr、Cu、Zn、As则有10%~75%的可能性产生生物毒害效应,而Cd、Pb和Hg造成的生物毒害效应的可能性较小.ERMQ评价结果表明,阳澄西湖沉积物中重金属造成生物毒害的风险较大,其余湖区发生重金属生物毒害的风险较小.     

Simultaneous quantification of fifty-one odor-causing compounds in drinking water using gas chromatography-triple quadrupole tandem mass spectrometry

A wide range of compounds with various structural features can cause taste and odor(TO)problems in drinking water. It would be desirable to determine all of these compounds using a simple analytical method. In this paper, a sensitive method combining liquid–liquid extraction(LLE) with gas chromatography-triple quadrupole tandem mass spectrometry(GC–MS/MS)was established to simultaneously analyze 51 odor-causing compounds in drinking water,including organic sulfides, aldehydes, benzenes, phenols, ethers, esters, ketones, nitrogenous heterocyclic compounds, 2-methylisoborneol and geosmin. Three deuterated analogs of target analytes, dimethyl disulfide-d6, benzaldehyde-d6 and o-cresol-3,4,5,6-d4,were used to correct the variations in recovery, and five isotope-labeled internal standards(4-chlorotoluene-d4, 1, 4-dichlorobenzene-d4, naphthalene-d8, acenaphthene-d10, phenanthrene-d10 respectively) were used prior to analysis to correct the variations arising from instrument fluctuations and injection errors. The calibration curves of the target compounds showed good linearity(R2 0.99, level = 7),and method detection limits(MDLs) below 1/10 of the odor threshold concentrations were achieved for most of the odorants(0.10–20.55 ng/L). The average recoveries of most of the analytes in tap water samples were between 70% and 120%, and the method was reproducible(RSD 20%, n = 7). Additionally, concentrations of odor-causing compounds in water samples collected from three drinking water treatment plants(DWTPs) were analyzed by this method.According to the results, dimethyl trisulfide, dimethyl disulfide and indole were considered to be the key odorants responsible for the swampy/septic odor. 2-Methylisoborneol and geosmin were detected as the main odor-causing compounds for musty/earthy odor in DWTP B.     

一种适用于深水压试验的传压隔热装置设计

目的真实高效地进行深水压环境的温度模拟。方法提出一种深水压试验压力加载过程中的恒温实现方法,通过开展基于皮囊的结构设计、密封性设计、导热性研究等工作,设计一种适用于深水压试验的传压隔热装置,对其进行理论分析和仿真计算。结果该装置可以实现液体温度在较长时间内基本恒定,具有良好的传压隔热性能。结论在建立的实验系统上进行了试验研究,实现了深水压环境模拟试验中压力载荷同步条件下液体温度小范围恒定功能,该技术为深水压环境试验的相关技术研究提供了技术储备。