典型工业恶臭源恶臭排放特征研究

恶臭污染具有主观性和复杂性特点,结合使用仪器分析和嗅觉方法,可以从成分和感官两方面充分反映恶臭污染特征.本文参考USEPA TO14A和GB/T 14675-93方法,选择天津滨海新区内的6个不同类型的工业恶臭源,包括制药、喷漆、炼油、石化、树脂合成和橡胶,采集了各类源工艺流程中通过有组织方式排放的恶臭废气,测定了废气的感官臭气浓度并定量分析了其中的恶臭VOCs物质.使用臭气浓度、恶臭指数及统计学方法进行研究,结果发现,炼油源和制胶源的废气具有非常严重的感官刺激性.甲硫醇等硫化物是炼油源和制胶源的主要特征恶臭物质;苯乙烯和甲苯分别是合成树脂源和喷涂源的特征恶臭组分;对苯二甲酸(PTA)源和制药源属于混合型恶臭源.甲苯是喷漆源和制药源的标识组分;二硫化碳是制胶源的标识组分;间,对-二甲苯可以用来标识石化PTA污染源;炼油源的标识组分为三氯乙烯、氯乙烷和1,2-二溴乙烷;苯乙烯是合成树脂源的标识组分.     

典型酿造业厂界无组织排放VOCs污染特征与风险评价

为探明酿造企业厂界无组织排放VOCs的浓度特征、恶臭污染及健康风险,采用便携式气相色谱-质谱仪对典型酿造企业醋厂和酒厂厂界无组织排放VOCs进行监测,分析研究其VOCs的浓度水平和组成特征,采用阈稀释倍数和感官测定法对VOCs进行恶臭分析,并进行了健康风险评价.结果表明,醋厂和酒厂厂界无组织排放VOCs的总浓度分别为0.968 mg·m~(-3)和0.293 mg·m~(-3).醋厂排放的VOCs中乙酸乙酯和乙酸含量较高,分别占总VOCs的76.3%和13.5%.酒厂排放的VOCs中以乙醇和己酸乙酯为主,分别占总VOCs的56.3%和30.4%.含氧VOCs是酿造企业污染源排放的主要组分.两厂总恶臭指数均大于1,表明其无组织VOCs排放对大气环境存在恶臭污染,且其臭气浓度均超过恶臭污染物厂界标准限值.醋厂和酒厂VOCs致癌风险指数分别为2.45×10~(-6)和5.25×10~(-6),超过了EPA致癌风险值(1.0×10~(-6)),但未超过OSHA致癌风险值(1.0×10~(-3))_及ICRP最大可接受的风险值(5.0×10~(-5)).     

天津滨海新区工业源VOCs及恶臭物质排放特征

参考USEPA TO-14A/15方法,选择天津市滨海新区内的6个不同类型的工业源,包括制药、自行车制造、炼油、石化、树脂合成和橡胶,对各类源工艺流程中有组织排放源排放的挥发性有机物(VOCs)进行定量分析,得到了源成分谱;并将各类源排放的恶臭物质浓度与嗅觉阈值进行对比,对其引发恶臭污染的潜在能力做出评价.结果显示,上述各类排放源的生产工艺中的VOCs总浓度分别为16.8,115.3,204.6,225.3,10.9,191.7mg/m3. 根据源成分谱分析结果,制药源和自行车喷漆车间的排气中甲苯比例分别为79.1%和94%;石化企业源中总二甲苯比例超过60%;橡胶企业脱硫工序,排放以硫化物为主;树脂合成工业,主要原料苯乙烯在排气中检出比例达51.8%;炼油源排气成分复杂,以卤代烃和硫化物为主.同时各类工业源均存在一定的恶臭污染,橡胶、炼油源的硫化物污染,树脂合成工业源的苯乙烯污染,石油化工源的混合污染,都应引起足够的重视.     

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.     

典型工业无组织源VOCs排放特征

选取制药厂、酿酒厂和橡胶厂分析了不同工艺过程VOCs排放特征.结果表明,制药厂安乃近合成和氨基比林合成的VOCs排放以苯、甲苯和苯乙烯等苯系物为主,乙酰氨基酚合成的VOCs排放主要以C4～C6的烷烃为主,酿酒厂和橡胶厂VOCs排放均以甲苯、乙苯和间,对二甲苯为主.采用最大增量反应活性法对臭氧生成潜势进行分析,制药厂安乃近合成和氨基比林合成VOCs单位臭氧生成潜势以苯、甲苯等苯系物为主;乙酰氨基酚合成以顺-2-丁烯、甲苯和异戊烷为主;酿酒厂、橡胶厂以甲苯、乙苯、间,对二甲苯为主.同时采用阈稀释倍数对VOCs进行恶臭分析,制药厂和酒厂无组织排放VOCs恶臭污染程度较轻,橡胶厂的伸缩装置车间和硫化车间的无组织VOCs排放存在一定程度的恶臭污染.     

北京市安定生活垃圾填埋场VOCs恶臭物质及其臭气强度

挥发性有机物(VOCs)是填埋场重要的恶臭源之一.为了深入了解造成填埋场恶臭的VOCs及其臭气强度情况,在2014年7—8月采用固相微萃取(SPME)-气相色谱(GC)-质谱(MS)联用法测定了北京市安定生活垃圾卫生填埋场内各代表性地点的VOCs.共确认了48种化合物,包括烷烃、烯烃、芳香烃、环烷烃、萜类、酯类、醛酮类、卤代烃、醇类及含硫化合物和含氮化合物.烷烃的种类最多,达到13种,其次是芳香烃,为9种.以内标法和外标法相结合测定了其中35种物质的含量,发现浓度在0.05~40 mg·m~(-3)之间.在厂区入口和作业面浓度最高的VOC是2,2,4,6,6-五甲基庚烷,在沼气干管是甲苯.从实际经验和臭气强度出发,建立了一种恶臭物质筛选方法,即首先以检出频次和各地点浓度比值筛选出可能的恶臭物质,然后由臭气强度确定最终的恶臭物质.筛选结果表明,填埋场内的恶臭VOCs是对伞花烃、对二甲苯、乙苯、甲苯和邻二甲苯,其中对伞花烃和对二甲苯对恶臭贡献尤为显著.这些恶臭VOCs浓度之间呈现出显著的相关关系,表明这些物质均来源于填埋场内生活垃圾的降解过程.     

厨余垃圾堆肥过程中恶臭物质分析

恶臭污染已成为生活垃圾堆肥过程中的主要环境问题.以大类粗分后的厨余垃圾作为研究对象,利用嗅觉测定法和GC-MS分析了不同阶段堆肥尾气的臭气浓度和恶臭化合物的种类及其排放浓度,并对不同堆肥阶段臭气浓度和恶臭物质排放浓度的相关性进行分析.结果表明,厨余垃圾堆肥过程中共检测到43种挥发性有机物,其中含硫臭气物质5种,烃类化合物22种,芳香烃类化合物11种,其它物质5种.通过相关性分析,发现硫化氢、甲硫醇、1,3-二甲基苯和邻二甲苯与臭气浓度极显著相关(P<0.01),二甲二硫和对二甲苯与臭气浓度显著相关(P<0.05),因此在厨余垃圾堆肥过程中要对这6种臭气物质进行重点监测和控制.     

恶臭污染源环境影响评价要点问题探讨

针对城市恶臭发生源的无组织与无组织排放方式及臭气成分复杂且大多属复合臭气成分的特点,重点对恶臭源的监测、组分分析方法以及源强综合评价等关键问题进行了研究和总结。     

汽车制造企业恶臭来源及影响分析

挥发性有机物(VOCs)是工业恶臭的重要来源之一.本文以某汽车制造企业为研究对象,对其产生的恶臭来源及对敏感点居民区的影响进行采样和分析.2016年11月15~17日,分别采用三点比较式臭袋法和大气预浓缩仪-气相色谱(GC)-质谱(MS)联用法对该企业厂区内各个车间的排气筒、厂界和敏感点的臭气浓度和VOCs组分进行定性、定量分析.结果表明,该企业整车厂和发动机厂各个车间排气筒的臭气浓度均未超标,发动机厂厂界的臭气浓度未超标,但整车厂的厂界和敏感点的臭气浓度均超过标准限值.监测共确认54种VOCs物种,包括芳香烃、卤代烃、烷烃、烯烃、环烷烃、酮类、酯类、醚类、醇类、含硫化合物和含氧环化合物.其中,卤代烃种类最多,其次是芳香烃.由此可知,汽车制造恶臭类代表物质主要是卤代烃和芳香烃.根据敏感点居民区特征VOCs物种的质量浓度、检知嗅阈和阈稀释倍数筛选出敏感点居民区的典型恶臭物质为1,3-丁二烯.针对涂装车间所用涂料进行定性分析,结果表明,绝大部分特征VOCs物种均来自涂料成分.恶臭贡献最大的1,3-丁二烯,在排除敏感点居民区周边其他污染源影响的情况下,推断其来源是整车厂涂装车间的喷涂和烘干工艺所产生的.建议企业采用含VOCs组分较低的环保涂料或更高处理效率的RTO净化装置,以减少汽车制造过程对居民区敏感点的恶臭影响.     

沥青路面铺设VOCs排放特征及风险评估

为探究沥青路面铺设VOCs的排放特征、气味效应及毒性作用,分别对沥青路面不同铺设阶段排放的VOCs进行监测.结果显示,沥青路面铺设排放的VOCs组成以烷烃、烯烃和芳香烃为主,检出的65种VOCs浓度范围为46.69~2179 μg/m³,按照铺路流程依次降低,为路面摊铺>路面压实>路面冷却>路面常温服役,其特征VOCs为十一烷、正戊烷、丙烯、甲苯、邻二甲苯、间二甲苯、对二甲苯、甲基丙烯酸甲酯、乙酸正丁酯;芳香烃是影响沥青路面铺设臭气指数的主要污染物;沥青路面铺设VOCs致癌风险指数范围为1.89×10^-6~5.35×10^-5,主要贡献物为苯、乙苯2种致癌组分,存在较大的潜在致癌风险.     

Distribution and ecological effect of mercury in Laogang landfill, Shanghai, China

Laogang landfill near Shanghai is the largest landfill in China, and receives about 10000 t of daily garbage per day, Samples of topsoil and plants were analyzed to evaluate mercury pollution from the landfill. For topsoil samples, there were significant correlations among total mercury （HgT）, combinative mercury （Hgc） and gaseous mercury （HgG）, and content of total organic carbon （TOC）, but, no significantly relationship was found between Hg content and filling time. Hg content changes in vertical profiles with time showed that the average Hgv of profiles 1992, 1996, and 2000 was similar, but their average HgG was quite different. HgT was significantly correlated with Hgc in profile 1992 and 2000, and Hgv was significantly correlated with Hg6 in profile 1996. HgG/Hgv ratio in profile samples decreased in the order of （HgG,/HgT）1992〉（HgG/HgT）1996〉〉（HgG/HgT）2000. A simple outline of Hg release in landfill could be drawn： with increasing of filling time, degradation undergoes different biodegradation, accordingly, gaseous mercury goes through small, more, and small proportion to total mercury. Distribution of Hg in plants was inhomogeneous, following the order of leaf〉root〉stem. The highest value of leaf may be associated with higher atmospheric Hg from landfill. Ligneous plants （e.g. Phyllostachys glanca, Prunus salicina and Ligustrum lucidum） are capable of enriching more Hg than herbaceous plants.     

EDTA-enhanced phytoremediation of lead contaminated soil by Bidens maximowicziana

Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils.Bidens maximowicziana is a new Pb hyperaccumulator,which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb.The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues.The Pb distribution order in the B. maximowicziana was:leaf>stem>root.The effect of amendments on phytoremediation was also studied.The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application.Compared with CK(control check),EDTA application promoted translocation of Pb to overground parts of the plant.The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg.This research demonstrated that B.maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil,especially,combination with EDTA.     

Decomposition of alachlor by ozonation and its mechanism

Decomposition and corresponding mechanism of alachlor, an endocrine disruptor in water by ozonation were investigated. Results showed that alachlor could not be completely mineralized by ozone alone. Many intermediates and final products were formed during the process, including aromatic compounds, aliphatic carboxylic acids, and inorganic ions. In evoluting these products, some of them with weak polarity were qualitatively identified by GC-MS. The information of inorganic ions suggested that the dechlorination was the first and the fastest step in the ozonation of alachlor.     

Enzymatic oxidation of aqueous pentachlorophenol

The influence of the nonionic surfactant Tween 80 on pentachlorophenol （PCP） oxidation catalyzed by horseradish peroxidase was studied. The surfactant was tested at concentrations below and above its critical micelle concentration （CMC）. Enhancement of PCP removal was observed at sub-CMCs. The presence of Tween 80 in the reaction mixture reduced enzyme inactivation which occurred through a combination of free radical attack and sorption by precipitated products. A simple first-order model was able to simulate time profiles for enzyme inactivation in the presence or absence of Tween 80. At supra-CMCs, the surfactant caused noticeable reductions in PCP removal, presumably through micelle partitioning of PCP which precluded the hydrophobic PCP molecule from interacting with the enzyme.     

基于综合水质标识指数和对应分析法的校园河道水质评价

以三峡大学的校园河道求索溪为研究对象,利用综合水质标识指数法确定求索溪水质类别,分析其水质时空变化规律,并利用对应分析法得出求索溪中不同监测点的主要污染因子.研究结果表明:求索溪整体的综合水质标识指数为7.423,整体水质为劣V类(地表水环境质量标准GB 3838-2002)且黑臭.从时间变化来看,求索溪4月份的水质最差,5月份次之,4、5月份所有监测点的水质都劣于V类且黑臭;8月份水质最好,水质为Ⅳ类;从空间分布来看,8个监测点综合水质标识指数均超过6.0,水质为劣V类,其中6号监测点的水质相对最好,监测点3号的水质相对最差;对应分析法得出求索溪的整体水体污染程度受总氮因子的影响最大,其次为总磷.该研究拟为求索溪及类似校园河道的水环境治理研究提供基础依据和参考.     

Effects of chitosan on growth of an aquatic plant (Hydrilla verticillata) in polluted waters with different chemical oxygen demands

Effects of chitosan on a submersed plant, Hydrilla verticillata, were investigated. Results indicated that H. venicillata could prevent ultrastructure phytotoxicities and oxidativereaction from polluted water with high chemical oxygen demand (COD). Superoxide dismutase (SOD) activity and malondialdehyde (MDA) contents in H. verticillata treated with 0.1% chitosan in wastewater increased with high COD (980 mg/L) and decreased with low COD (63 mg/L), respectively. Ultrastructural analysis showed that the stroma and grana of chloroplast basically remained normal. However, plant cells from the control experiment (untreated with chitosan) were vacuolated and the cell interval increased. The relict of protoplast moved to the center, with cells tending to disjoint. Our findings indicate that wastewater with high COD concentration can cause a substantial damage to submersed plant, nevertheless, chitosan probably could alleviate the membrane lipid peroxidization and ultrastructure phytotoxicities, and protect plant cells from stress of high COD concentration polluted water.     

Removal of cadmium using MnO2 loaded D301 resin

MnO2 loaded weak basic anion exchange resin D301 （Anion exchange resin, macroreticular weak basic styrene） as adsorbent has been prepared and applied to the removal of cadmium. The adsorption characteristics have been investigated with respect to effect of pH, equilibrium isotherms, removal kinetic data, and interference of the coexisting ions. The results indicated that the Cd^2＋ could be efficiently removed using MnO2 loaded D301 resin in the pH range of 3-8 from aqueous solutions with the co-existence of high concentration of alkali and alkaline-earth metals ions. The saturate adsorption capacity of the Cd^2＋ was 77.88 mg/g. The adsorption process followed the pseudo first-order kinetics. The equilibrium data obtained in this study accorded excellently with the Langmuir adsorption isotherm.     

Effect of coagulation pretreatment on the fouling of ultrafiltration membrane

The purpose of this study is to understand the effect and mechanism of preventing membrane fouling, by coagulation pretreatment, in terms of fractional component and molecular weight of natural organic matter （NOM）. A relatively higher molecular weight （MW） of hydrophobic compounds was responsible for a rapid decline in the ultrafiltration flux. Coagulation could effectively remove the hydrophobic organics, resulting in the increase of flux. It was found that a lower MW of neutral hydrophilic compounds, which could remove inadequately by coagulation, was responsible for the slow declining flux. The fluxes in the filtration of coagulated water and supernatant water were compared and the results showed that a lower MW of neutral hydrophilic compounds remained in the supernatant water after coagulation could be rejected by a membrane, resulting in fouling. It was also found that the coagulated flocs could absorb neutral hydrophilic compounds effectively. Therefore, with the coagulated flocs formed on the membrane surface, the flux decline could be improved.     

Penetration analysis of elements and bioleaching treatment of spent refractory for recycling

Acidithiobacillus ferrooxidans ATCC23270 and Acidithiobacillus thiooxidans TM-32 were used for bioleaching of spent refractories of aluminium and copper melting furnaces for their recycling.Firstly,penetration of elements into aluminium melting furnace refractory was investigated and it was found that up to 7 cm from surface was contaminated.Comparison on leaching efficiency by the strains ATCC23270 and TM-32 found that the strain ATCC23270 could treat larger amount of the refractories than the strain TM-32 could do.In the experiment of bioleaching of spent refractory aluminium melting furnace by the strain ATCC23270,high leaching efficiency were obtained on Al,Si,and Ca,and extremely low leaching performance was,however,shown on the rest of elements i.e.,Na,Mn,and Zn.Under the strain TM-32 use,relatively high leaching performance was recognized on Al,Si,Ca,Na,Mn,and Zn.In the experiment of bioleaching for spent refractory copper melting furnace,almost the same leaching trends were shown on Cu,Zn,Al,and Si under the strains ACTT23270 and TM-32 uses.     

Simultaneous removal of ammonium and phosphate by zeolite synthesized from coal fly ash as influenced by acid treatment

Zeolite synthesized from fly ash （ZFA） without modification is not efficient for the purification of NH4＋ and phosphate at low concentrations that occur in real effluents, despite the high potential removal capacity. To develop an effective technique to enhance the removal efficiency of ammonium and phosphate at low concentrations, ZFA was modified with acid treatment and the simultaneous removal of ammonium and phosphate in a wide range of concentration was investigated. It was seen that when compared with untreated ZFA, only the treatment by 0.01 mol/L of H2SO4 significantly improved the removal efficiency of ammonium at low initial concentrations. The behavior was well explained by the pH effect. Treatment by more concentrated H2SO4 led to the deterioration of the ZFA structure and a decrease in the cation exchange capacity. Treatment by 0.01 mol/L H2SO4 improved the removal efficiency of phosphate by ZFA at all initial P concentrations, while the treatment by concentrated H2SO4 （≥0.9 mol/L） resulted in a limited maximum phosphate immobilization capacity （PIC）. It was concluded that through a previous mild acid treatment （e.g. 0.01 mol/L of H2SO4）, ZFA can be used in the simultaneous removal of NH4＋ and P at low concentrations simulating real effluent.