阜新市化石燃料燃烧源大气污染物排放源清单及特征分析

为了向阜新市化石燃料燃烧源大气环境管理工作提供排放清单的理论依据,通过对阜新市(5区、2县、2园区)环境统计数据的收集和实地调查,结合本地化大气排放因子,建立了2017年阜新市化石燃料燃烧源涵盖SO_2、NO_x、PM_(2. 5)、PM_(10)、挥发性有机物(VOCs)、CO、黑碳(BC)、有机碳(OC) 8类大气污染物的排放清单。利用Arc Gis 10. 2遥感技术,分析了大气污染物时空分配特征。研究结果表明:8类污染物排放量分别为11 915. 49、7 215. 33、3 607. 78、2 002. 96、4 594. 72、4 277. 05、384. 15、16. 62 t;各类污染物的贡献率以及区域空间分布特征均存在差异,但其在时间上表现出一致性(除PM_(2. 5)),即在时间上均表现出两个峰值,高峰分别出现在夏季的七、八月和冬季的十一月至一月;县区中彰武县污染物排放较多,市区中太平区污染物排放较多;火力发电和热力供应企业对阜新市大气污染贡献较大,应当重点管控。     

一株芽孢杆菌在低氮源浓度培养基中的生长与氨氮去除特性

对菌株YB3进行了16S rRNA基因序列进化分析,并分别以NH_4Cl、NaNO_2、NaNO_3、尿素和蛋白胨为单一氮源,配制了5种低氮源浓度培养基,研究YB3在与养殖水体相近营养水平条件下的生长与氨氮去除特性.结果显示,菌株YB3属于蜡样芽孢杆菌(Bacullis cereus),在5种培养基中均能够生长,菌悬液(吸光度OD600为1.0)接种量为1.0%(v/v)时,OD600由0.010增长到0.100~0.117.在NH_4Cl培养基中,YB3的氨氮去除速率为1.23 mg·L~(-1)·d~(-1),去除率为93.5%.在尿素、蛋白胨等有机氮源培养基中,YB3将首先导致氨氮的积累,累积倍数分别为51.69和3.38,之后开始去除,去除速率为1.56和0.29 mg·L~(-1)·d~(-1),去除率为93.7%和26.8%.结果也表明,提高YB3接种量至8.0%(v/v),可以使蛋白胨培养基氨氮累积倍数下降至2.02,去除速率提高至1.07 mg·L~(-1)·d~(-1),去除率最终达到98.4%.NaNO_2和NaNO_3培养基中均未检测到氨氮,而NH_4Cl、尿素和蛋白胨培养基中也未检测到NO_2~--N和NO_3~--N,表明YB3的硝化、亚硝化和反硝化作用均不强烈,去除氨氮的同时将不会造成NO_2~--N和NO_3~--N等的大量积累.本文为菌株YB3在养殖水体调控与净化中的应用研究提供了实验基础和理论支持.     

米糠与氧化钙、过磷酸钙联用钝化Pb污染土壤

研究了生物质材料米糠及其与氧化钙、过磷酸钙联用对土壤中重金属Pb的钝化作用.结果表明,向土壤中加入米糠可增大土壤pH值,增加土壤中重金属Pb的稳定性.米糠投加量每增加2%,土壤pH值增大约0.3.米糠投加量增大,Pb稳定效率也随之增大,6%米糠投加量60 d时,Pb稳定化效率达到38.06%,弱酸提取态降低28.90%.6%米糠+2%氧化钙联用、6%米糠+0.6%过磷酸钙联用均可对土壤中Pb产生较好的钝化效果,60 d时的稳定效果分别为47.36%、44.85%.6%米糠+2%氧化钙对Pb污染土壤有较好的钝化调节作用,可增大土壤pH,从而促进酸可提取态Pb向其他稳定形态转变.     

Source apportionment of PM2.5 light extinction in an urban atmosphere in China

Haze in China is primarily caused by high pollution of atmospheric fine particulates (PM_2.5). However, the detailed source structures of PM_2.5 light extinction have not been well established, especially for the roles of various organic aerosols, which makes haze management lack specified targets. This study obtained the mass concentrations of the chemical compositions and the light extinction coefficients of fine particles in the winter in Dongguan, Guangdong Province, using high time resolution aerosol observation instruments. We combined the positive matrix factor (PMF) analysis model of organic aerosols and the multiple linear regression method to establish a quantitative relationship model between the main chemical components, in particular the different sources of organic aerosols and the extinction coefficients of fine particles with a high goodness of fit (R² = 0.953). The results show that the contribution rates of ammonium sulphate, ammonium nitrate, biomass burning organic aerosol (BBOA), secondary organic aerosol (SOA) and black carbon (BC) were 48.1%, 20.7%, 15.0%, 10.6%, and 5.6%, respectively. It can be seen that the contribution of the secondary aerosols is much higher than that of the primary aerosols (79.4% versus 20.6%) and are a major factor in the visibility decline. BBOA is found to have a high visibility destroying potential, with a high mass extinction coefficient, and was the largest contributor during some high pollution periods. A more detailed analysis indicates that the contribution of the enhanced absorption caused by BC mixing state was approximately 37.7% of the total particle absorption and should not be neglected.     

Comparison of the effects of aluminum and iron(III) salts on ultrafiltration membrane biofouling in drinking water treatment

Coagulation plays an important role in alleviating membrane fouling, and a noticeable problem is the development of microorganisms after long-time operation, which gradually secrete extracellular polymeric substances (EPS). To date, few studies have paid attention to the behavior of microorganisms in drinking water treatment with ultrafiltration (UF) membranes. Herein, the membrane biofouling was investigated with different aluminum and iron salts. We found that Al₂(SO₄)₃·18H₂O performed better in reducing membrane fouling due to the slower growth rate of microorganisms. In comparison to Al₂(SO₄)₃·18H₂O, more EPS were induced with Fe₂(SO₄)₃·xH₂O, both in the membrane tank and the sludge on the cake layer. We also found that bacteria were the major microorganisms, of which the concentration was much higher than those of fungi and archaea. Further analyses showed that Proteobacteria was dominant in bacterial communities, which caused severe membrane fouling by forming a biofilm, especially for Fe₂(SO₄)₃·xH₂O. Additionally, the abundances of Bacteroidetes and Verrucomicrobia were relatively higher in the presence of Al₂(SO₄)₃·18H₂O, resulting in less severe biofouling by effectively degrading the protein and polysaccharide in EPS. As a result, in terms of microorganism behaviors, Al-based salts should be given preference as coagulants during actual operations.     

有机溶剂使用企业挥发性恶臭有机物排放特征及特征物质识别

为研究有机溶剂使用企业挥发性恶臭有机物排放特征以及识别各企业恶臭特征物质,测定了南方某工业区内典型溶剂使用企业挥发性恶臭有机物(VOCs)的排放成分.结果表明,不同企业间物质组成存在一定的差异,同一企业不同工艺流程物质组成也存在一定差异,汽车制造企业:面漆喷涂车间排气筒醇类(21.87%)和酯类(21.62%)是重要的VOCs排放种类;面涂烘干车间芳香烃(41.14%)排放比例最高.电子元件生产企业:喷涂排气筒酯类(67.99%)是重要的VOC排放种类.涂料生产企业:两家涂料企业酯类物质排放比例均是最高,但1号涂料企业芳香烃(24.37%)排放比例较高,2号涂料企业酮类(18.88%)排放比例较高.印刷企业主要是醇类物质(99.32%).制冷设备生产企业:烷烃排放比例最高(83.01%).结合物质浓度和阈稀释倍数,初步识别酯类(乙酸乙酯、乙酸丁酯、乙酸异丁酯)、芳香烃(甲苯、乙苯、苯乙烯)、醇酮类(乙醇、甲基异丁酮、2-丁酮)为有机溶剂使用企业恶臭特征物质.     

大通河流域降水结构的演变特征及其驱动力探究

论文以青藏高原大通河流域为例,分别采用基于日、月降雨集中度指标（CI和CIM）,表征大通河流域的降水结构特征,并分析其演变特征;采用交叉小波分析探究太阳黑子和大气环流异常指数太平洋10 a涛动（PDO）、厄尔尼诺/南方涛动（ENSO）、北极涛动（AO）与流域降水结构变化的联系。结果表明：1）流域南部的年均CI值高于北部,中部的年均CIM值高于流域其他部分;2）流域年CI值上升趋势明显,而其年CIM值具有明显下降趋势,且两者的一致性被破坏;3）太阳黑子对于流域降水结构影响最为显著,AO和ENSO的影响次之,PDO的影响最弱。研究成果有助于揭示大通河流域降水结构的驱动机理,为其模拟与预测奠定坚实的基础。     

象山港潮余流结构及水体半交换时间数值研究

基于三维FVCOM模型研究了象山港的潮流场特征,同时耦合Lagrange粒子追踪法及保守污染物输运模型,研究了湾内余环流结构、粒子长期迁移轨迹和湾内水交换特征等。结果表明:象山港海域为非正规的半日浅海潮,其中M2为其主要分潮;潮致余环流的特征明显,湾外分为两支,一支自牛鼻山水道东岸流入,绕六横岛经佛渡水道南部流出;第二支由佛渡水道进入湾内,并在口门内偏转再经牛鼻山水道西侧流出,其部分水体在牛鼻山水道中部与第一支汇合;西沪港以西峡湾内的余流基本指向湾口,西沪港内余流则指向口门;考虑湾内水体与湾外整体交换时,西沪港的污染物半交换时间在90 d左右,黄墩港和铁港内半交换时间在180 d左右,两支余流作用范围内的湾口半交换时间在20 d以内。     

恶臭污染精准模拟的峰/均值因子研究进展

大气扩散模型是进行恶臭污染管理的有效工具,它可以评估恶臭污染的影响范围和影响程度.然而,由于恶臭污染的特殊性,通常使用的大气扩散模型模拟结果是小时均值浓度,不能满足恶臭污染评估对瞬时最大值的需求,所以,需要引入峰/均值因子,将扩散模型计算结果从均值浓度（如1 h均值）转换到短时间峰值浓度（如1 s峰值）.通过研究国内外峰/均值因子相关文献,以及国内外恶臭标准、评估技术中峰/均值因子的相关规定,对峰/均值因子的研究理论、影响因素和计算方法进行系统地分析、总结和评述.现阶段的研究表明,峰/均值因子受大气稳定度、距离、地形、污染源类型等多种因素的影响.然而,由于影响峰/均值因子的因素较多,大部分国家和地区只能在其恶臭环境影响评价导则中将峰/均值因子设置为一个或一组固定值,与实际情况不符,因此具有一定的局限性.结合我国的恶臭污染评价现状,建议将峰/均值因子理论引入我国,综合考虑我国的恶臭污染特点、气象特征、地形等,探讨建立适用于我国的不同地区不同污染源类型的峰/均值因子.峰/均值因子的研究可为我国恶臭污染的精准模拟、恶臭防护距离的制订、恶臭暴露-效应关系的研究提供基本理论与技术支持.