欧盟化学物质法规管理选择分析对我国化学物质环境管理的启示

法规管理选择分析(RMOA)是欧盟对受关注的化学物质在法定管理方面开展的具体问题具体分析的策略,即"一品一策".其能够促使主管部门在决策化学物质的管控法规时尽快达成共识,并有力地支撑欧盟高关注物质路线图(SVHC Road-map)和一体化规管战略(IRS)的实施.RMOA是一项有效的法规管理与选择决策的程序,但我国对于RMOA的研究尚处于起步阶段.本研究介绍了RMOA这项决策的产生和发展,分析了该决策所取得的成果,阐明了其在欧盟化学物质管理中作用与意义.提出了适合中国化学物质法规管理选择分析的方法,以期对我国化学物质环境风险管理体系的建立健全提供参考.     

水环境中的有机磷阻燃剂及其生物富集和生物转化研究进展

随着世界范围内对溴代阻燃剂的禁用,有机磷阻燃剂(OPFRs)被作为替代品广泛应用于建筑、纺织、化工、电子以及家装材料等行业,生产和使用量逐年上升.由于OPFRs在环境和生物体中普遍检出,且多种化合物具有致癌性、神经毒性和生殖毒性,对生态环境和人体健康造成潜在威胁,目前已成为国际上的一个研究热点.笔者重点综述了河流、湖泊和海洋等水体及沉积物中OPFRs污染现状,水生生物对OPFRs的生物富集和生物放大,以及OPFRs在水生生物体内和体外生物代谢的研究进展,并对目前该领域仍有待探讨的问题及研究趋势进行了展望.     

典型四环素类抗生素的预测无效应浓度和风险评估

四环素类抗生素是一类广谱抗生素,对生态环境存在潜在风险.本研究以四环素和土霉素为研究对象,根据欧盟现有化学物质风险评价技术指导文件(TGD),推导不同环境介质中四环素和土霉素的预测无效应浓度(PNEC),并采用风险商值(RQ)法对我国部分地区水质、淡水沉积物和土壤的暴露风险进行评估.结果 表明,我国水质、淡水沉积物及土壤中四环素的PNEC值分别为0.115 μg·L-1、423 μg·kg-1(湿质量)和57 μg· kg-1(湿质量);土霉素的PNEC值分别为4.93μg·L-1、1.78x104 μg·kg1(湿质量)和3.16×103μg·kg-1(湿质量).淡水沉积物风险区域主要集中在海河,土壤风险区域主要集中在山东省、四川省彭州市、辽宁省沈阳市等,部分区域点位存在潜在的生态风险.研究结论可为四环素类抗生素的生态环境风险评价提供科学依据.     

Transparent exopolymer particles (TEPs)-associated protobiofilm: A neglected contributor to biofouling during membrane filtration

• Bacteria could easily and quickly attached onto TEP to form protobiofilms. • TEP-protobiofilm facilitate the transport of bacteria to membrane surface. • More significant flux decline was observed in the presence of TEP-protobiofilms. • Membrane fouling shows higher sensitivity to protobiofilm not to bacteria level. Transparent exopolymer particles (TEPs) are a class of transparent gel-like polysaccharides, which have been widely detected in almost every kind of feed water to membrane systems, including freshwater, seawater and wastewater. Although TEP have been thought to be related to the membrane fouling, little information is currently available for their influential mechanisms and the pertinence to biofouling development. The present study, thus, aims to explore the impact of TEPs on biofouling development during ultrafiltration. TEP samples were inoculated with bacteria for several hours before filtration and the formation of “protobiofilm” (pre-colonized TEP by bacteria) was examined and its influence on biofouling was determined. It was observed that the bacteria can easily and quickly attach onto TEPs and form protobiofilms. Ultrafiltration experiments further revealed that TEP-protobiofilms served as carriers which facilitated and accelerated transport of bacteria to membrane surface, leading to rapid development of biofouling on the ultrafiltration membrane surfaces. Moreover, compared to the feed water containing independent bacteria and TEPs, more flux decline was observed with TEP-protobiofilms. Consequently, it appeared from this study that TEP-protobiofilms play a vital role in the development of membrane biofouling, but unfortunately, this phenomenon has been often overlooked in the literature. Obviously, these findings in turn may also challenge the current understanding of organic fouling and biofouling as membrane fouling caused by TEP-protobiofilm is a combination of both. It is expected that this study might promote further research in general membrane fouling mechanisms and the development of an effective mitigation strategy.     

Evaluation of the technoeconomic feasibility of electrochemical hydrogen peroxide production for decentralized water treatment

• Gas diffusion electrode (GDE) is a suitable setup for practical water treatment. • Electrochemical H₂O₂ production is an economically competitive technology. • High current efficiency of H₂O₂ production was obtained with GDE at 5–400 mA/cm². • GDE maintained high stability for H₂O₂ production for ~1000 h. • Electro-generation of H₂O₂ enhances ibuprofen removal in an E-peroxone process. This study evaluated the feasibility of electrochemical hydrogen peroxide (H₂O₂) production with gas diffusion electrode (GDE) for decentralized water treatment. Carbon black-polytetrafluoroethylene GDEs were prepared and tested in a continuous flow electrochemical cell for H₂O₂ production from oxygen reduction. Results showed that because of the effective oxygen transfer in GDEs, the electrode maintained high apparent current efficiencies (ACEs,>80%) for H₂O₂ production over a wide current density range of 5–400 mA/cm², and H₂O₂ production rates as high as ~202 mg/h/cm² could be obtained. Long-term stability test showed that the GDE maintained high ACEs (>85%) and low energy consumption (<10 kWh/kg H₂O₂) for H₂O₂ production for 42 d (~1000 h). However, the ACEs then decreased to ~70% in the following 4 days because water flooding of GDE pores considerably impeded oxygen transport at the late stage of the trial. Based on an electrode lifetime of 46 days, the overall cost for H₂O₂ production was estimated to be ~0.88 $/kg H₂O₂, including an electricity cost of 0.61 $/kg and an electrode capital cost of 0.27 $/kg. With a 9 cm² GDE and 40 mA/cm² current density, ~2–4 mg/L of H₂O₂ could be produced on site for the electro-peroxone treatment of a 1.2 m³/d groundwater flow, which considerably enhanced ibuprofen abatement compared with ozonation alone (~43%–59% vs. 7%). These findings suggest that electrochemical H₂O₂ production with GDEs holds great promise for the development of compact treatment technologies for decentralized water treatment at a household and community level.     

Exogenously applied oxalic acid assists in the phytoremediation of Mn by Polygonum pubescens Blume cultivated in three Mn-contaminated soils

• The OA supply significantly increased the water-extractable Mn in all soils. • All OA supply levels promoted plant growth in unexplored soil. • Low OA supply level promoted plant growth in explored and tailing soils. • OA amendment increased the Mn concentrations and total Mn in P. pubescens. • P. pubescens experienced less Mn stress in unexplored soil than in the other two soils. The current study evaluated the effects of oxalic acid (OA) application on the growth and Mn phytoremediation efficiency of Polygonum pubescens Blume cultivated in three different manganese (Mn)-contaminated soils sampled from an unexplored area (US), an explored area (ES) and a tailing area (TS) of the Ertang Mn mine, South China. The supplied levels of OA were 0 (control), 1 (low level), 3 (medium level), and 9 (high level) mmol/kg, referred to as CK, OA1, OA3 and OA9, respectively. The results revealed that the average water-extractable Mn concentrations US, ES and TS amended with OA increased by 214.13, 363.77 and 266.85%, respectively. All OA supply levels increased plant growth and Mn concentrations in US. The low OA supply level increased plant growth in ES and TS; however, contrasting results were found for the medium and high OA supply levels. Plant Mn concentrations and total Mn increased in ES and TS in response to all OA supply levels. Total Mn in the aerial parts increased by 81.18, 44.17 and 83.17% in US, ES and TS, respectively; the corresponding percentages for the whole plants were 81.53, 108.98 and 77.91%, respectively. The rate of ·O₂⁻ production and malondialdehyde (MDA) concentrations increased in response to OA amendment, especially the medium and high OA supply levels in ES and TS. In general, antioxidant enzymes might play a vital role in alleviating Mn stress in plants cultivated in US, while non-enzymatic antioxidants might be the main factor for plants cultivated in ES and TS.     

京津冀及周边地区秋冬季大气污染物排放变化因素解析

基于大气污染源排放清单技术方法,定量分析2016~2017年秋冬季"跨年霾"至2019~2020年秋冬季"疫情霾"期间京津冀及周边地区主要大气污染物排放量变化,解析大气污染防治政策实施带来的减排和疫情造成的活动水平下降对主要污染物排放的贡献,并利用空气质量模型模拟分析不利气象条件下措施减排和疫情影响对空气质量改善的贡献.结果表明,从"跨年霾"（2016-12-16~2017-01-14）至"疫情霾"（2020-01-22~2020-02-14）该区域主要大气污染物排放量大幅下降50%左右,不利气象条件下,区域PM_2.5平均浓度可削减40%以上.措施减排主要来自火电、钢铁等重点工业行业提标改造和工业锅炉、民用燃煤等燃煤源治理,对SO₂和PM_2.5排放量的削减贡献较大,贡献率分别为67.1%和53.4%;疫情主要影响移动源和轻工业活动水平,对NO_x和VOCs排放量的削减贡献较大,贡献率分别为71.9%和68.2%.措施减排对区域空气质量改善贡献突出,有效抑制了重污染过程的强度和范围.在"跨年霾"的不利气象条件下,措施减排使区域PM_2.5平均浓度下降26%,重度及以上污染天数减少44%.受疫情影响,区域PM_2.5平均浓度继续下降24%,重污染持续时间和范围进一步缩减.     

黄土高原不同降水量区旱作苹果园地水分生产力和土壤干燥化效应模拟与比较

为了揭示黄土高原旱作苹果园深层土壤干燥化对果园产量的长远影响,确定果园适宜利用年限,应用WinEPIC模型定量模拟分析了1965—2009年黄土高原半湿润区洛川、半湿润易旱区白水、半干旱区延安、半干旱易旱区静宁等不同降水量区旱作苹果园地水分生产力演变和深层土壤水分动态变化规律,并比较了其区域差异。结果表明：洛川、白水、延安和静宁果园产量均呈现出“先逐年升高达到最大值,之后随当地降雨量变化而波动性降低”趋势,45 a平均值分别为26.05、23.89、22.29和20.51 t/hm²;1~20 a生果园平均年耗水量均高于同期年降水量,导致果园深层土壤干燥化强烈,洛川1~22 a生、白水1~21 a生、延安1~18 a生、静宁1~16 a生的土壤逐月有效含水量呈明显波动性降低趋势,年均土壤干燥化速率分别为59.6、56.9、63.9和64.9 mm/a,静宁>延安>洛川>白水,此后苹果园地土壤有效含水量在较低水平上随季节降水变化波动;洛川、白水、延安和静宁苹果园地0~15 m土层土壤湿度剖面分布变化剧烈,土壤湿度逐年降低,土壤干层出现时间分别为13 a生、11 a生、7 a生和6 a生,土壤干层逐年加厚,在20 a生时均已超过11 m,21 a生以后3~15 m土层土壤湿度保持相对稳定的干燥化状态;4个试点果园水分生产力和土壤干燥化效应区域差异显著,果园土壤水分可持续利用年限为20~25 a。     

太湖不同生态型湖区悬浮颗粒磷空间分布和降解速率

对太湖不同生态型湖区水体悬浮颗粒物含量,有机磷组成及降解特征进行分析,研究了富营养化湖泊颗粒磷性质及其对水体磷循环的影响.太湖颗粒P平均占水体TP浓度的75.86％;不同生态类型湖区间颗粒物性质差异明显,河口区和湖心区的颗粒物含量高于藻型湖区和草型湖区,但颗粒物有机质比例分布却相反.利用³¹P液相核磁共振法（³¹P-NMR）发现太湖悬浮颗粒P的成分包括膦酸酯,正磷酸盐,磷酸单酯,磷酸二酯,焦磷酸盐和多聚磷酸盐6类,含量分别为1.06%,50.99%,33.02%,2.48%,10.68%和3.80%.不同生态型湖区之间颗粒P组成差异明显,河口区正磷酸盐含量最高,达到82.57%,藻型湖区和湖心区颗粒有机磷比例最高,分别达到达到 64.02%和63.95%;颗粒物焦磷酸盐和多聚磷酸盐可能以藻源性颗粒物来源为分别与Chla浓度呈显著相关（P<0.05; P<0.01）.颗粒态生物可利用性磷（PEHP）与正磷酸盐显著相关（P<0.05）,说明颗粒物正磷酸盐是颗粒物生物可利用性磷的重要来源.太湖PEHP降解速率平均为47.3min,PEHP占水体生物可利用磷（EHP）的65.16%,说明颗粒P是水体溶解性反应磷（SRP）补充的重要来源.     

基于多区域CGE模型的水污染间接经济损失评估——以长江三角洲流域为例

通过构建长江三角洲流域多区域CGE模型,模拟了2011年水污染对长江三角洲流域内部地区（上海、流域内浙江、流域内江苏）造成的间接经济损失.并且构建间接影响系数来反映流域内不同区域和行业受水污染的间接波及程度.研究结果表明：水污染对流域内区域的经济影响差异明显,从GDP绝对值减少量来看,上海GDP损失最大（161.3亿元）,但从GDP百分比变化来看,流域内浙江损失更为显著（2.84%）;上海经济对长江三角洲流域水污染最为敏感,其间接经济损失将是其直接经济损失的3.5倍左右,而流域内江苏、流域内浙江仅为0.92倍和1.98倍.