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在我国经济发展势头如此迅猛的背景下,城市污染问题日益严重。城市黑臭水体对城市生态环境造成严重影响,如果不能及时进行治理,则会对原有水生态循环系统造成破坏,影响城市居民正常生活。本文首先对城市黑臭水体产生原因进行分析,然后提出有效的治理对策。 相似文献
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Potential particulate pollution derived from UV-induced degradation of
odorous dimethyl sulfide 总被引:1,自引:0,他引:1
UV-induced degradation of odorous dimethyl sulfide (DMS) was carried out in a static White cell chamber with UV irradiation. The
combination of in situ Fourier transform infrared (FT-IR) spectrometer, gas chromatograph-mass spectrometer (GC-MS), wide-range
particle spectrometer (WPS) technique, filter sampling and ion chromatographic (IC) analysis was used to monitor the gaseous and
potential particulate products. During 240 min of UV irradiation, the degradation e ciency of DMS attained 20.9%, and partially
oxidized sulfur-containing gaseous products, such as sulfur dioxide (SO2), carbonyl sulfide (OCS), dimethyl sulfoxide (DMSO),
dimethyl sulfone (DMSO2) and dimethyl disulfide (DMDS) were identified by in situ FT-IR and GC-MS analysis, respectively.
Accompanying with the oxidation of DMS, suspended particles were directly detected to be formed by WPS techniques. These
particles were measured mainly in the size range of accumulation mode, and increased their count median diameter throughout
the whole removal process. IC analysis of the filter samples revealed that methanesulfonic acid (MSA), sulfuric acid (H2SO4) and
other unidentified chemicals accounted for the major non-refractory compositions of these particles. Based on products analysis and
possible intermediates formed, the degradation pathways of DMS were proposed as the combination of the O(1D)- and the OH- initiated
oxidation mechanisms. A plausible formation mechanism of the suspended particles was also analyzed. It is concluded that UV-induced
degradation of odorous DMS is potentially a source of particulate pollutants in the atmosphere. 相似文献
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藻类大量死亡后极易产生致嗅物.我们模拟了藻类的生长死亡过程,观测除藻后水体理化性质和生物性质的改变情况以及致嗅物的成分及浓度,以确定致嗅物质产生的途径.由于藻类死亡后细胞解体,藻类细胞中的氮、磷物质释放到水体中,导致水体的富营养化程度反而升高,而叶绿素-a也呈现下降趋势,整个试验过程后期溶解氧为0,水体产生嗅味物质,可采用吹扫捕集/固相微萃取—气相色谱—质谱法和顶空固相微萃取气质联用法分析致嗅物质.实验证明,当藻型湖泊的藻类被基本去除后,整个水体的初级生产力受到严重的破坏,威胁到水生态系统的安全性,可导致水体进一步恶化. 相似文献
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沉积物微生物是农村黑臭水体物质循环和有机物降解等过程的主要驱动者,其群落结构组成常因外界环境的微小变化而变化.以菏泽市东明县29个农村黑臭水体为研究对象,测定农村黑臭水体上覆水和沉积物氮、磷及重金属等污染物指标,结合Illumina测序结果,分析农村黑臭水体沉积物细菌群落组成和多样性特征及其与环境因子的相关性.结果表明,该区域农村黑臭水体上覆水和沉积物中污染物分布范围均较广.与农业面源相比,以农村生活污水为主要污染来源的农村黑臭水体上覆水中氮、磷污染物浓度更高,分别是农业面源的3.1倍和1.5倍.此外,该区域农村黑臭水体沉积物中重金属含量处于较低水平,普遍低于菏泽市土壤元素背景值.该区域农村黑臭水体沉积物细菌群落的优势菌门为变形菌门、放线菌门、绿弯菌门、厚壁菌门和酸杆菌门,这5种优势菌门的序列总和占全部序列的70.3%~83.6%.γ-变形菌纲、α-变形菌纲、厌氧绳菌纲和放线菌纲是沉积物细菌群落的优势菌纲;硫杆菌属和假节杆菌属是其优势菌属.Spearman相关性分析结果表明,环境因子中DO、 COD、 TN、 TP和有机质对农村黑臭水体沉积物细菌菌属有显著影响(P<0.05),沉... 相似文献
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Müller T Thissen R Braun S Dott W Fischer G 《Environmental science and pollution research international》2004,11(3):152-157
BACKGROUND, AIMS AND SCOPE: Composting facilities are known to release odorous volatiles due to biodegradation of municipal waste and plant residues. Although odour perception and its grading is influenced by experience, attitude and adaptation, these emissions have created a lack of acceptance for residents in the vicinity of composting facilities. Enclosure of compost pile halls, ventilation systems and biofilters are often insufficient to minimise the burden of compost-derived compounds in the air. Moreover, economic considerations forced smaller communities to establish less sophisticated facilities with open storage areas and other relevant sources for wind-borne dispersal of bioaerosols. Aim of the present study was to characterise the immission and dispersal of microbial volatiles (MVOC) and, besides, to find coincidences between MVOC and compost odour. METHODS: In the course of this study, the surroundings of two composting facilities, differing in their type of process engineering, were investigated for emission of volatiles in the environment. Both microbially and plant-derived substances were assessed, several of which have low odour thresholds. Air samples were taken in distances ranging from 50 to 800 m in a downwind direction from each facility. RESULTS AND DISCUSSION: Compost-derived and microbial volatile organic compounds (MVOC) were found at distances of up to 800 m from the composting facilities. Terpenes like alpha-pinene, camphene and camphor were the dominant compounds and coincided with typical compost odour, whereas several typical MVOC were not found at greater distances. The terpenes in combination with certain MVOC may play an important role in the perception of compost odour. Exposure concentrations were not of toxicological relevance, but sensory irritation and psychohygienic effects due to an annoyance potential of such compounds should not be dismissed. RECOMMENDATIONS AND OUTLOOK: Although terpenes are generally associated with pleasant odour characteristics, they seemed to contribute to malodours in a mixture with other VOC, in this context of volatile waste from compost facilities. Malodorous emissions from biowaste have to be considered as sources of health complaints and the investigation of mixtures of compost-derived volatiles is still inevitable. Exposure levels have to be discussed taking VOC mixtures into account. Within composting facilities, technical devices have to be improved to minimise dispersal of volatiles to prevent residents from immissions eventually causing health complaints. 相似文献
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为了深入了解工业园区恶臭污染情况、保障工业园区工作人员的工作环境安全,以珠海市某工业园区为分析对象,采集园区内涉及8种行业类型、14个工业恶臭源的主要工艺流程中通过有组织方式排放的恶臭废气,分析了14个排放源的恶臭VOCs排放特征,测定了感官臭气浓度,应用理论臭气强度法确定了各排放源的特征恶臭物质,并对各排放源的恶臭废气进行了致癌和非致癌风险评估.结果表明:①14个排放源排放的物质种类相同、含量差异较大,纤维和电池制造及烃类、酸酐、酯类和溶剂合成的恶臭VOCs排放以烷烯烃为主;炼油源、PTA合成源和乳胶合成源废气中苯及苯系物含量最高;酯类化合物是活性炭加工、树脂合成源和喷涂源废气排放的主要物质;陶瓷制造源和添加剂合成源排放的废气以羰基化合物和硫化物为主;②14个排放源的废气均具有较为强烈的感官刺激性,润滑油添加剂合成和乳胶类合成排放的废气感官刺激性最严重.其中,添加剂合成源的特征恶臭物质为乙硫醇、乙硫醚、正丁醇和甲苯,乳胶合成源的特征恶臭物质为苯乙烯、丙苯、异丙苯、丙烯酸丁酯和1,3-丁二烯;③14个排放源恶臭废气的终生致癌风险LCR值范围为3. 06×10-7~1. 06×10-2,其中炼油源、PTA合成源、酯类合成源和乳胶合成源排放废气存在较大潜在风险;非致癌风险HI总值范围为0. 02~51. 66,其中乳胶合成、酯类合成、炼油、PTA合成和纤维制造存在一定的非致癌健康风险.乳胶合成源、酸酐合成源和树脂合成源厂界均存在潜在致癌风险. 相似文献
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为认知水源地型水库异味发生风险及其规律,本研究于异味风险高危期(夏季),对江苏17个省级水源地型水库开展了水质、浮游生物和异味物质状况调查.结果表明,本次调查的17个水库普遍存在富营养化程度偏高(如藻类生物量偏大和水体透明度偏低)的问题,约三分之一的水库出现部分水层异味物质2-甲基异莰醇(MIB)浓度超标,MIB平均浓度为(13. 7±20. 7) ng·L-1,表明江苏省水库型水源地普遍存在MIB风险;多个水库检出土臭素(GSM),但其浓度均没有超过10ng·L-1的饮用水标准浓度(最大浓度为4. 6 ng·L-1);同步水质调查及统计分析表明,MIB浓度和水体叶绿素a浓度、水体透明度、悬浮颗粒物浓度、富营养化指数等重要水质指标及浮游植物生物量(特别是蓝藻生物量)相关性显著(P 0. 05),其中MIB与叶绿素a、富营养化指数呈极显著的相关关系(P 0. 01).因此,水源地型水库的异味物质风险与水库的富营养化密切相关;实施营养盐外源输入削减、提高流域植被覆盖度、科学调控渔业养殖规模等水体富营养化控制措施是水库异味物质控制的关键. 相似文献