国内成功运营的餐厨垃圾处理厂臭气排放特征研究简

选择目前国内成功运营的餐厨垃圾资源化处理厂为采样点，采用气相色谱-质谱联用（GC/MS）技术对该厂的主要工段，如卸料室、破碎室、湿热反应器出气口、好氧发酵仓、厌氧发酵区以及厂界的臭气进行了定性和定量的分析。结果表明，6个采样点共检测出包括芳香烃、硫化物、卤代物、烯烃、烷烃、醇、醛、酮和酯在内的9类66种物质，各采样点臭气总浓度分别为：11.738、18.390、30.917、25.097、4.737和2.635 mg/m³。其中湿热反应器出气口处恶臭气体浓度最高，其芳香烃、硫化物、卤代物、烯烃、烷烃、酮及酯类物质均高于其他检测点，需对该工段进行重点监测和控制。恶臭排放特征分析表明，各点的H₂S浓度均超过嗅觉阈值，除厂界外甲硫醇和二甲二硫检测值均超过嗅觉阈值。     

餐厨垃圾处理厂挥发性有机物释放特征

选择目前国内成功运营的餐厨垃圾处理厂为采样点,该厂以利用餐厨垃圾生产生物蛋白饲料和厌氧发酵为主要工艺,采用气相色谱/质谱联用(GC/MS)技术对挥发性有机物(VOCs)浓度较高的工段,如破碎室、湿热反应器、好氧发酵仓进行了定性和定量分析.结果表明,3个采样点共检测出65种物质,包括醇、醛、酮、酯、芳香烃、硫化物、卤代物、烯烃和烷烃9类.湿热反应器排放VOCs浓度最高且包含物质种类最多,其中酮、酯、芳香烃、硫化物、卤代物、烯烃及烷烃类物质浓度均高于其他检测点,需对该工段进行重点监测和控制.     

郑州市环境空气中挥发性卤代烃污染特征与健康风险评价

用苏玛罐采样、气相色谱/质谱法分析,研究郑州市环境空气中挥发性卤代烃(VHCs)的污染特征并对其健康风险进行评价。结果显示,郑州市环境空气中共定性检出43种VHCs,其中卤代烷烃28种,卤代烯烃9种,卤代芳香烃6种,卤代烷烃、卤代烯烃、卤代芳香烃的年均质量浓度分别为67.40、34.70、20.30μg/m~3,郑州市各功能区环境空气中VHCs化合物种类稍有差异,背景点VHCs浓度与其他功能区并无显著差异,说明VHCs污染呈现区域性特征;垂直方向上,卤代烷烃浓度随高度呈先降后升趋势,卤代烯烃和卤代芳香烃浓度随高度呈先升后降趋势。健康风险评价结果显示,VHCs单体化合物对人体的非致癌风险均在安全范围内,而总风险超出了安全范围,氯乙烯、三氯乙烯、四氯化碳、氯仿、1,2-二溴乙烷、1,2-二氯乙烷和1,1,2-三氯乙烷的致癌风险超出美国环境保护署规定的可接受值;致癌风险合计为5.32×10~(-4),说明长期暴露于环境空气中对人群健康具有一定危害。     

恶臭及其防治

一、臭气物质的嗅觉阈值、控制对象与嗅觉控制浓度 1.臭气物质的嗅觉阈值和控制对策恶臭属感觉公害,它不仅使人感到不愉快和厌恶,而且臭气中的不少物质同样能危害人体健康.恶臭公害的发生率不次于噪音.据报道,日本近几年来发生的恶臭公害案件,约占全国公害案件的20-25%之多,1971年日本政     

城市污水厂主要处理单元恶臭及挥发性有机物的逸散

在污水处理厂的主要处理工艺段设置采样点,采用在线监测仪,检测空气中恶臭及挥发性有机物(VOCs)的浓度,明确主要恶臭物质和排放源,研究恶臭及VOC在不同季节的逸散特征。结果表明,恶臭和VOC的排放主要集中在进水区,浓度与进水水质相关。粗格栅间是主要的恶臭源,其恶臭、TVOC、硫化物和胺类的浓度分别为3 458.54~5 028.03OU、120~221 mg/m3、253~464 mg/m3和15~36 mg/m3,占各个监测点浓度总量的80.6%、93%、90%和89%。主要的恶臭物质为硫化氢和氨,其浓度对应的臭气强度超过4级。恶臭与VOC的排放呈现季节变化,夏季的浓度明显高于冬季。相关性分析显示,恶臭浓度与TVOC、硫化物、胺类浓度具有明显的相关性。     

餐厨垃圾两相厌氧发酵产甲烷相恶臭排放规律

为了研究餐厨垃圾两相厌氧发酵产甲烷相恶臭排放规律,在中温(35℃)条件下,以餐厨垃圾为发酵底物进行中试规模的两相连续式厌氧发酵试验,并对一个周期内不同时间段产甲烷相产生的气体进行采样,分析其臭气浓度和物质浓度,结合各组分的阈稀释倍数,筛选出主要的恶臭污染物。结果表明,在发酵系统稳定运行阶段,产甲烷相产生的臭气浓度较大,都在23万以上;产甲烷相产生的恶臭物质主要包括硫化物、萜烯类、含氧类和芳烃类四类化合物,其中质量浓度最高的恶臭物质是硫化氢,超过了150 mg/m3;产甲烷相的主要致臭物质是硫化物,其中贡献最大的是硫化氢,其阈稀释倍数都在26万以上,其次为乙硫醇﹥甲硫醇﹥乙硫醚,这3种物质的阈稀释倍数都在4 000以上;除了这4种硫化物,丁醛对恶臭的贡献也比较大,其阈稀释倍数也在4 000以上。     

天津市不同功能区大气挥发性有机物污染特征及来源分析

利用天津市某交通居民混合区(以下简称混合区)和某废旧机电拆解加工工业区(以下简称工业区)的大气挥发性有机物(VOCs)在线监测数据,分析了天津市不同功能区大气VOCs的浓度水平、组成特征、季节变化和污染来源。结果表明,混合区监测的烷烃、不饱和脂肪烃和芳香烃3类VOCs的质量浓度分别为48.26、15.34、34.45μg/m3,总VOCs质量浓度为98.05μg/m3;工业区监测的烷烃、不饱和脂肪烃、芳香烃、卤代烷烃、卤代烯烃和卤代芳香烃6类VOCs的质量浓度分别为18.79、10.76、9.41、43.24、12.86、2.16μg/m3,总VOCs质量浓度为97.22μg/m3。混合区和工业区的大气VOCs浓度均为夏季最高,但混合区秋季次高,冬季最低,而工业区冬季次高,春季最低。混合区VOCs主要来源于机动车尾气排放和化石燃料的燃烧;工业区VOCs主要来源于有机溶剂和氟利昂等制冷剂、发泡剂的挥发。     

生活垃圾填埋场填埋气中挥发性有机物释放规律分析

于2007年2月在上海老港垃圾填埋场选取10个不同填满年限的填埋单元进行填埋气的采样分析,用色谱-质谱技术检测了填埋气中的挥发性有机物(VOCs).检测到脂肪烃、卤代脂肪烃、单环芳烃、醚和酮等5类22种化合物,其中11种为美国环境保护署优先控制污染物,甲苯、乙苯和间,对二甲苯的浓度较高.填满时间距采样时间较近(1～2年)的填埋单元检出的VOCs种类较多,脂肪烃和单环芳烃的浓度随填满时间的增加呈现较明显的衰减特征,而卤代脂肪烃、醚和酮的浓度与填满时间的相关性不显著.检出的5种化合物中,1,1,1三氯乙烷、甲苯和间,对-二甲苯的浓度均低于美国加利福尼亚州环保局推荐的健康阈值,氯乙烯和苯则超过该阈值.     

天津市滨海新区夏季挥发性有机物的污染特征分析

对天津市滨海新区夏季挥发性有机物(VOCs)进行在线观测,分析其夏季污染特征。结果表明:83种检出VOCs平均质量浓度为288.14μg/m3,各类化合物浓度贡献排序为烷烃(39.8%)卤代链烃(26.5%)芳香烃(13.9%)烯烃(13.1%)炔烃(4.4%)卤代芳香烃(2.3%),各组分中浓度最高的为正丁烷和正戊烷,占VOCs比例高达8.1%和7.0%;苯和甲苯也有相当含量,平均质量浓度均超过7μg/m3,分别占VOCs的2.5%和2.4%。天津市滨海新区VOCs日变化呈单谷型,与交通早晚高峰关系不大,苯/甲苯(体积比)为1.32,说明化石工业排放等对天津市滨海新区大气中VOCs影响较机动车尾气显著。聚类分析发现,天津市滨海新区VOCs来源分为3类,一类是汽油挥发和液化石油气、天然气泄漏,一类是化石工业和其他工业生产过程排放,一类是机动车尾气及植物排放,其中前两类为主要来源。     

二次热解吸-气相色谱-质谱分析室内挥发性有机化合物

采用二次热解吸-气相色谱.质谱法对室内空气进行了定量和定性分析,共检出挥发性有机物245种,包括烷烃、烯烃、芳香类化合物、卤代烃、醇、醛、酮、酯、醚等化合物,住宅类室内空气中挥发性有机化合物浓度平均值明显高于办公类室内这些物质的浓度平均值,对室内空气样品分析中的特例进行了可能的污染源解析,推测室内过量使用液体胶粘剂有可能是引起污染物严重超标的原因之一.     

Characteristic analysis for odor gas emitted from food waste anaerobic fermentation in the pretreatment workshop

Gas chromatography–mass spectrometry, olfactometry, and other related methods were applied for the qualitative and quantitative analysis of the characteristics of odorous gases in the pretreatment workshop. The composition of odorous gases emitted from municipal food waste was also investigated in this study. The results showed that the tested gases are mainly composed of aromatic gases, which account for 49% of the total volatile organic compounds (VOC) concentrations. The nitrogenous compounds comprise 15% of the total concentration and the other gases comprise the remaining 36%. The level of odor concentration ranged from 2523 odor units (OU) m^?3 to 3577 OU m^?3. The variation of the total chemical composition ranged from 19,725 µg m^?3 to 24,184 µg m^?3. Among the selected four sampling points, the discharge outlet was detected to have the highest concentration in terms of odor, total chemical, sulfur compounds, and aromatics. The correlation analysis showed that the odor concentrations were evidently related to the total chemical composition, sulfur compounds, and aromatics (P < 0.05, n = 5). The odor activity value analysis identified the top three compounds, hydrogen sulfide (91.8), ethyl sulfide (35.8), and trimethylamine (70.6), which contribute to air pollution complaint of waste materials.

Implications: Currently, the amount of food waste has rapidly increased, which leads to difficulty in waste management and more odorous gases released as air pollution. In processing of food wastes by anaerobic fermentation, odorous gases are generated, which significantly affect the workers and occupants in the plant. In the pretreatment workshop for anaerobic decomposition, the odorous gases are generated because of the stacking and decomposition of food wastes. The gases emitted mainly consist of organic gases because the food wastes are mainly organic materials. The other odors that comprise 1% of the gases are S-compounds, aromatics, esters, alkanes, and limonene, which result in unpleasant odors that are harmful to the health.     

清洁型一体化污水处理系统研究

针对城镇分散型污水处理的特点,开发了一种清洁型一体化污水处理系统.该系统由立体循环一体化氧化沟(IODVC)、污泥减量区和臭气处理区优化整合而成.中试试验结果表明:该系统可以使微生物有效处理污水,并实现污泥减量和臭味气体净化.经该系统处理的污水,出水COD、NH4 -N、SS的浓度维持在35 mg/L、1 mg/L和20 mg/L以下;同时,臭味气体得到有效去除,氨气和硫化氢等臭味气体可以达标排放;经过生物减量,排放的剩余污泥减少了46.4%;污泥的比阻有所降低.本系统占地少,运行操作简便,无二次污染,属于适合中小型污水处理的技术工艺.     

Treatment of odor by a seashell biofilter at a wastewater treatment plant

Biofilters are becoming an increasingly popular treatment device for odors and other volatiles found at wastewater treatment plants. A seashell media based biofilter was installed in April 2011 at Lake Wildwood Wastewater Treatment Plant located in Penn Valley, California. It was sampled seasonally to examine its ability to treat odorous compounds found in the air above the anaerobic equalization basin at the front end of the plant and to examine the properties of the biofilter and its recirculating water system. The odor profile method sensory panels found mainly sulfide odors (rotten eggs and rotten vegetable) and some fecal odors. This proved to be a useful guidance tool for selecting the required types of chemical sampling. The predominant odorous compounds found were hydrogen sulfide, methyl mercaptan and dimethyl sulfide. These compounds were effectively removed by the biofilter at greater than 99% removal efficiency therein reducing the chemical concentrations to below their odor thresholds. Aldehydes found in the biofilter were below odor thresholds but served as indicators of biological activity. Gas chromatography with mass spectrometry and gas chromatography with sensory detection showed the presence of dimethyl disulfide and dimethyl trisulfide as well, but barely above their respective odor thresholds. The neutrality of the pH of the recirculating water was variable depending on conditions in the biofilter, but a local neutral pH was found in the shells themselves. Other measurements of the recirculating water indicated that the majority of the bio-activity takes place in the first stage of the biofilter. All measurements performed suggest that this seashell biofilter is successful at removing odors found at Lake Wildwood. This study is an initial examination into the mechanism of the removal of odorous compounds in a seashell biofilter.

Implications:?This paper presents a thorough examination of a seashell media biofilter, a sustainable treatment technology used to remove reduced sulfide compounds. The durable performance of the seashell biofilter ensures that odors will be adequately controlled, preventing odor nuisance to surrounding residences, which is an emerging problem faced by waste management facilities. The odor profile method technique used in this study can be applied in many situations by waste management facilities and regulatory air management organizations for source tracking in relation to prevention and management of odor complaints, respectively.     

Investigating the capacity of an activated sludge process to reduce volatile organic compounds and odor emissions.

The effects of hydrogen sulfide (H2S) diffusion into activated sludge (AS) on odor and volatile organic compound (VOC) concentrations in offgas were studied over an 8-week period. Most VOCs detected in the offgas of both aeration tanks were aromatic hydrocarbons. The VOC concentrations generally decreased when H2S was introduced to the AS compared with the control, indicating a negative effect of H2S on VOC removal. Two volatile organic sulfur compounds present in the test AS offgas showed an increase followed by a decrease during H2S peak loads. Six VOCs and odor concentration increased during the introduction of an H2S peak; however no correlation was observed between H2S and odor concentration. The increase in odor concentration resulted from the increase in the concentration of six aromatic VOCs, which had their removal slowed down during a 100-ppmv H2S peak. Activated sludge diffusion provides effective H2S removal with minimal affect on odor emissions.     

Measurement of biosolids compost odor emissions from a windrow, static pile, and biofilter.

A pilot study was conducted to compare odor emissions from a windrow process and an aerated static pile and to determine the odor reduction efficiency of a pilot two-phase biofilter for odor control of biosolids composting. Chemical compounds identified as responsible for odors from biosolids composting include ammonia, dimethyl disulfide, carbon disulfide, formic acid, acetic acid, and sulfur dioxide (or carbonyl sulfide). Aeration was found to reduce the concentration of ammonia, formic acid, and acetic acid by 72, 57, and 11%, respectively, compared with a nearby windrow, while dimethyl sulfide, carbon disulfide, and sulfur dioxide (or carbonyl sulfide) concentrations were below detection limits. Using dilution-to-threshold olfactometry, aeration followed by biofiltration was found to reduce the odor from biosolids composting by 98%. Biofiltration also altered the character of odor emissions from biosolids composting, producing a less offensive odor with an earthy character. Biofiltration was found to reduce the concentration of ammonia, dimethyl disulfide, carbon disulfide, formic acid, acetic acid, and sulfur dioxide (or carbonyl sulfide) by 99, 90, 32, 100, 34, and 100%, respectively. The concentrations of those odorants were estimated to be 3700, 110000, 26,37,5, and 1.2 times reported human detection limits before the two-phase biofilter, respectively, and 42,9600,18,0,3, and 0 times human detection limits after the biofilter, respectively.     

Industrial odor sources and air pollutant concentrations in Globeville,a Denver,Colorado neighborhood

An odor of unknown origin described as a “tar” or “asphalt” smell has become unbearable for many of Globeville, CO, residents over the past few years. Residents report during odor events burning eyes and throat, headaches, skin irritation, and problems sleeping. This study was undertaken to identify the potential sources of the odor and the concentrations of air pollutants making up the odor by conducting meteorological correlations and sampling for a panel of volatile organic compounds (VOCs), sulfur gases, and polycyclic aromatic hydrocarbons (PAHs) in the neighborhood and near suspected sources. Wind speed and direction data collected every 1 min in the neighborhood indicate that when the odor is noticed, the community is directly downwind of a wood preservation facility and an asphalt roofing facility. Air samples collected during high-intensity odor events have shown concentrations of methylene chloride, hexane, toluene, naphthalene, dibenz[a,h]anthracene, benzo[g,h,i]perylene, and indeno[1,2,3-cd]pyrene, each at least two times higher than background concentrations. Naphthalene and the other PAHs are known pollutants emitted from wood treatment processes, and are known to have a coal tar odor. Naphthalene was present in a sample collected directly adjacent to the Koppers facility and was not present in any background samples. Single-compound odor and health thresholds, however, were never surpassed. Given the technical and regulatory challenges of sampling odors and controlling emissions, it is recommended that Globeville residents and neighboring industry pursue a “good neighbor policy” to solve the odor issue. Specific offending industrial processes could be identified for which there exist cost-effective control technologies that would reduce exposure to odors and air toxics in Globeville.

Implications: Meteorological correlations and samples of volatile organic compounds (VOCs), sulfur gases, and polycyclic aromatic hydrocarbons (PAHs) in the Globeville, CO, neighborhood and near suspected sources during odor events indicate potential industrial sources of a transient and noxious odor. Legislative approaches have proven unfruitful and no health or odor thresholds were typically violated. New approaches are warranted to address odor mixture effects in neighborhoods near industrial facilities.     

Health risk assessment of odors emitted from urban wastewater pump stations in Tianjin,China

In order to evaluate the potential adverse health effects of odor emissions from wastewater pump stations (WWPSs) to human, a health risk assessment was performed to study the odors emitted from an urban WWPS in a residential area, Tianjin (in North China). First, 15 types of volatile organic compounds in the WWPS were collected and analyzed using gas chromatography-mass spectrometry. Next, Monte Carlo probabilistic modeling was applied to evaluate the potential health effects of four odors (chlorobenzene, dichloromethane, hydrogen sulfide, and carbon disulfide), which had higher concentrations. The results revealed that the 95th percentile of the total non-carcinogenic risk was approximately 1.73, which poses a threat to human health. In addition, hydrogen sulfide had the highest non-carcinogenic risk value of the four; the hazard quotient of hydrogen sulfide was estimated to be 1.60 at the 95th percentile, higher than the upper confidence limit (1.0). The 95th percentile of the carcinogenic risk was approximately 5.47E-08, much lower than the maximum acceptable level (1.0E-06). Finally, the influence of the input variables on the output was evaluated using sensitivity analysis, and contaminant concentration, reference concentration, and inhalation unit risk were the most influential variables.     

Characterization of odor released during handling of swine slurry: Part II. Effect of production type,storage and physicochemical characteristics of the slurry

The quality of rural life can be affected by offensive odors released from animal buildings and storage units. The objectives of this study were to compare the concentrations of odor and odorants above different types of stirred swine slurry to analyze the relationships between concentrations of odor (and odorants) and physicochemical characteristics of the slurry (i.e. pH, temperature, dry matter, volatile solids, and concentration of 22 chemical compounds); and to propose predictive models for the odor concentration (OC) based on these physicochemical characteristics (solely and in combination with concentrations of specific odorants in the air above the slurries). The study comprised data on concentrations of odor and odorants in the air above slurry samples (fresh and/or stored) collected from production units with farrowing sows, finishing swines, or weaning pigs at eight swine operations (N = 48). OC measured in the air above stirred swine slurry samples were not significantly different among production types or storage times. The physicochemical characteristics of the slurries were not useful for predicting OC or concentrations of hydrogen sulfide (or organic sulfides) above the slurry, but were related to concentrations of other emitted gases such as phenols and indoles (r² = 0.65–0.79, p <0.05), ammonia (r² = 0.86, p < 0.05) and carboxylic acids (r² = 0.23–0.59, p <0.05). There was good precision of predictive models of OC based on selected slurry characteristics (i.e. pH, dry matter, nitrogen content, sulfur content or concentrations of individual aromatic compounds and carboxylic acids) together with concentrations of specific odorants in the air (e.g. hydrogen sulfide) (r² between 0.70 and 0.92). This study suggests that predictive models could be useful for evaluating odor nuisance potentials of swine slurry during handling.