嗅辨员筛选及分组优化在建材产品气味浓度评价中的应用

为了使气味浓度结果反映气味污染的真实情况,合理筛选气味评价员及组建气味评价小组有重要意义。国内外相关标准中对于气味评价员筛选均有相应要求。本文分别依据标准嗅液法、正丁醇-动态稀释嗅觉仪法对气味评价员进行筛选,结果表明,正丁醇-动态稀释嗅觉仪法的筛选更严格。利用两种方法筛选的气味评价员组成不同的气味评价小组评价相同建材产品的气味浓度,数据表明,通过正丁醇-动态稀释嗅觉仪法筛选的气味评价小组气味浓度评价结果的精密度和重复性更好。通过正丁醇-动态稀释嗅觉仪法筛选的气味评价员依据正丁醇个人阈值进一步细分为Ⅰ类、Ⅱ类、Ⅲ类气味评价员,分析显示,优化气味评价小组的人员组成能更真实地反映实际情况,同时便于同级气味评价员的替换。     

一种预制型塑胶跑道的气味组成及来源分析

通过环境测试舱模拟夏季最高地表温度,考察一种典型预制型塑胶跑道的气味释放情况,分别用气相色谱-质谱法和分光光度法对其释放的气味气体中挥发性有机化合物和甲醛释放量进行测试.基于相对气味活度值法,分析确认该预制型塑胶跑道产品释放的气味气体中主要易致味物质的化学组成为二硫化碳、苯乙烯、4-异丙基甲苯、间(对)二甲苯、苯并噻唑...     

黄河水异味和藻类控制的生产性试验研究

针对黄河水藻类高发的现象,对水源地和沉砂池进行了取样分析,确定藻类为异味产生的根源.预处理试验结果表明,在投加20 mg/L聚合铁和10 mg/L硅酸钠的同时,投加0.4-1.0 mg/L聚二烯丙基二甲基氯化铵(FL45C)对藻类和浊度的去除以及臭和味的控制效果较好.     

生活垃圾填埋场臭气产生与控制探讨

阐述了生活垃圾填埋场恶臭气体的组成与来源,对填埋场臭气控制工作中存在的问题进行了研究,并提出了填埋场恶臭控制的具体对策,以期为城市生活垃圾无害化处理提供参考。     

饮用水除嗅味技术的研究进展

介绍了饮用水中致嗅味物质的种类及来源,概括了国内外对饮用水中嗅味控制技术的研究进展,总结了氧化预处理、吸附预处理、生物处理等技术法对饮用水嗅味的去除效果,对今后自来水厂生产饮用水的工艺改进具有指导意义。     

臭气污染的有效控制

针对城市垃圾和城市污水处理厂的臭气控制，介绍了一种比较有效的臭气污染控制技术即生物脱臭法，指出这种办法能从根本上解决臭气污染问题，并不易产生二次污染。     

Psychological bias caused by notification of odor name in sensory evaluation test of odor

“Tatami” is a traditional Japanese building material used as a floor mat made with rush. It used to be said that the smell of tatami is preferred by many Japanese, because almost all Japanese houses have had tatami rooms since early times. In this paper, the psychological bias of notification of material name was investigated. This kind of psychological bias seems to be a very important factor that affects the result of sensory test.     

Kinetics and mechanisms of formation of bromophenols during drinking water chlorination: assessment of taste and odor development

Halophenols are often reported as off-flavor causing compounds responsible for medicinal taste and odor episodes in drinking water. To better understand and minimize the formation of 2-bromophenol and 2,6-dibromophenol which have low odor threshold concentrations (OTCs, 30 and 0.5 ng/L, respectively) a kinetic data base for the chlorination and bromination of phenols was established by combination of kinetic measurements and data from literature. Second-order rate constants for the reactions of chloro- and bromophenols with chlorine and bromine were determined over a wide pH range. The second-order rate constants for bromination of phenols are about three orders of magnitude higher than for chlorination. A quantitative structure activity relationship (QSAR) showed a good comparability of second-order rate constants from this study with those published previously for different phenol derivatives. The quantification of product distribution of the formed halophenols demonstrated that chlorine or bromine attack in ortho position is favored with respect to the para position. A kinetic model was formulated allowing us to investigate the influence of chlorine dose and some water quality parameters such as the concentration of phenol, ammonia, bromide and the pH on the product distribution of halophenols. The kinetic model can be applied to optimize drinking water chlorination with respect to phenol-born taste and odor problems. In general, high chlorine doses lead to low concentrations of intermediate odorous chlorophenols and bromophenols. An increase in the ammonia or phenol concentration leads to a higher consumption of HOCl and therefore greater final concentration of intermediate bromophenols. The presence of higher bromide than phenol concentration also facilitates the rapid bromination pathway which leads to further bromination of 2,6-dibromophenol to higher brominated phenols. Laboratory-scale experiments on taste and odor formation due to the chlorination of phenol- and bromide-containing waters have confirmed the trend of the model calculations.     

高锰酸钾与粉末活性炭联用去除饮用水中嗅味

针对太湖B支流水体发臭现象严重、采用常规工艺处理很难去除嗅味物质的情况，通过试验考察了单独投加高锰酸钾、单独投加粉末活性炭以及高锰酸钾与粉末活性炭联用三种方法对嗅味的去除效果。静态及生产性试验结果表明：高锰酸钾与粉末活性炭联用工艺的除嗅效果最好，当高锰酸钾投加量为0．5mg／L、粉末活性炭投加量为40mg／L时，沉后水的嗅阈值仅为5，去除率达到了98．8％，并且可节省粉末活性炭投量约20％。此外，高锰酸钾与粉末活性炭联用对藻类也有较好的去除效果。     

嗅味层次分析法对饮用水中嗅味的识别

介绍了嗅味层次分析法（FPA）培训程序及其在饮用水嗅味识别中的应用案例。结果表明，按照FPA方法选择并培训的测试小组，对于实际水样中的异嗅味能够进行明确的定性和定量分析；FPA小组经嗅阈值及强度训练后，对典型土霉味物质（2-甲基异莰醇，MIB）和氯味物质NaClO的嗅阈值可分别达到4．82ng／L和0．03mg／L，同时检测出的嗅味强度与嗅味物质浓度间的关系符合Weber—Fechner Law关系式（R^2分别为0．97、0．99），且具有较好的重现性。采用该方法测定了北方某水厂各工艺段水样的嗅味变化情况。结果表明，FPA法可较好地用于评价水厂工艺对常见嗅味物质的处理效果，能够为水厂的运行提供可靠的感官分析手段。     

水厂除藻除嗅试验研究

针对高藻期水库水采用高锰酸盐复合药荆(PPC)、高锰酸钾(KMnO4)和氯进行了化学预氧化强化水厂除藻除嗅性能的试验研究,并与单独使用混凝剂时的处理效果进行了对比.结果表明,PPC对水库高藻水具有较好的除浊和除有机物效果,且高于KMnO4;PPC预氧化对藻类和臭味的去除效果高于KMnO4预氧化.     

Skin squames contribute to ammonia and volatile fatty acid production from bacteria colonizing in air‐cooling units with odor complaints

One of the most notable Indoor Air Quality problems is odor emission. This study investigated the potential contribution of skin squames to the production of ammonia (NH₃) and volatile organic acids (VFAs) by 7 bacteria isolated from air‐cooling (AC) units with complaints of urine and body odors. Our previous study showed that keratinolytic activity is higher in AC units with odor complaints than those without. In the offices where these units are located, the most likely source of keratins is from human skin squames. Most bacteria can produce NH₃ and VFAs in the skin squame culture. Some correlations between the levels of NH₃, , VFAs, and keratinolytic activity were found. The odor production pathway with skin squames was proposed. Staphylococcus haemolyticus was abundant in the AC units with odor problems and had a high level of keratinolytic activity in addition to odor production. For long‐term odor control, it is important to reduce the level of skin squames entering the AC units.     

Aging impairs the ability to detect gas odor

Weakened smelling is common in age. Two studies here show that this phenomenon frequently reveals itself in inability to detect ethyl mercaptan, the warning agent most commonly added to propane (LP-gas). The first study compared 21 young (18–25 years) with 21 old (70–85 years) persons for (a) detection threshold (average ten times higher in the elderly), (b) suprathreshold odor strength (weaker for the elderly at all levels), and (c) ability to identify common odors (the elderly did worse). Seven of the 21 elderly failed to detect ethyl mercaptan at or above a concentration associated with the boundary between acceptable and unacceptable levels of propane. Three of these failed to detect the odorant at a concentration where accompanying propane could explode. In the second study 50 of 110 persons over 60 years failed to detect odor reliably in commercial odorized propane diluted to the Department of Transportation's safety standard (one–fifth the lower explosive limit). Six of 52 persons under 40 also failed. The elderly person would seem at high risk of LP-gas fire. Reference: Joseph C. Stevens, William C. Cain,and David E. Weinstein, Aging Impairs the Ability to Detect Gas Odor, Fire Technology, Vol. 23, No. 3, August 1987, pp. 198–204. Note: The research was supported by NIH Grant AG-04287.     

Investigation of indoor chemical pollutants and perceived odor in an area with complaints of unpleasant odors

An uncomfortable smell was reported by employees of an IT office (information technological office) in a medical center. This problem started two years ago when the office was refurbished. The objectives of this study are to characterize the indoor air quality of this complaint area in terms of chemical pollutants and odor characteristics, and identify possible sources of this foul smell. Carbonyl chemicals and volatile organic compounds (VOCs) were investigated in this study, since these two groups are associated with odors and health effects. Additionally, the odor was evaluated by odor assessors (non-smokers) who recorded odor characters that appeared in offices. By comparing chemical measurements between complaint and non-complaint areas, calculating odor indices, and correlating odor and chemical measurements, we got results showing that a higher correlation coefficient is found between odor presence frequencies and VOC concentrations. Further investigating found nonanal and decanal are possible chemicals for malodors. The concentration levels of these two chemicals in the complaint area are higher than those in the non-complaint areas and exceeding odor thresholds. Possible sources of these long-chain aldehydes are formed during the oxidation degradations of fatty acids like linoleic acid, linolenic acid and oleic acid which are ingredients for many building products like linoleum and surface coating. In order to mitigate this malodor problem, extra and effective ventilation flow rate should be provided to reduce the concentrations of odorous chemicals and the precursors for these odorous chemicals.     

竹园第一污水处理厂除臭工程设计

分析了竹园第一污水处理厂的臭气污染源，确定了该污水厂除臭工程的范围（生物絮凝反应沉淀池的进水端和出水槽、污泥浓缩池、污泥脱水机房）及内容（降低H2S、NH3和臭气浓度）。针对主要污染源，经方案比选确定了采用天然植物提取液除臭方法，介绍了该除臭工程的设计及运行效果。结果表明，采用天然植物提取液除臭方法可使该污水厂的H2S和NH3指标达到厂界排放要求，但对臭气浓度的去除效果尚待提高。     

HS-SPME-GC法测定水中典型嗅味物质

研究了气相色谱仪（GC）测定水中典型噢味物质（土臭素、2-甲基异茨醇、2-甲氧基-3-异丙基吡啶、2-甲氧基-3-并丁基吡嗪和2，4，6-三氯苯甲醚）的改进方法。采用新型顶空-固相微萃取（head-space solid-phase microextraction，HS—SPME）方法对水样进行前期富集处理，然后利用气相色谱氢离子火焰检测器（FID）进行测定。在优化试验条件下对嗅味物质的测定结果显示，5种嗅味物质的峰面积与其浓度有较好的相关性，其相关系数〉0．87；该方法对5种嗅味物质的检出限值较低，其中对土臭素的检出限为0．4ng/L。改进后的测定方法适用于气相色谱仪，操作简单省时，对于推广嗅味物质的检测具有重要的实际意义。     

污水处理厂恶臭防治对策及环境影响评价的研究

城市污水处理厂的恶臭严重影响了污水处理厂周围居民的日常生活,通过对城市污水处理厂的恶臭来源和国内外污水处理厂恶臭防治措施的现状分析,重点从环评角度对污水处理厂恶臭的环境影响评价方法进行了研究,从实测、嗅闻调查以及大气防护距离的确定三个角度进行综合全面的评价分析.     

Development of predictive models for geosmin-related taste and odor in Kansas, USA, drinking water reservoirs

The presence of taste and odor compounds can greatly reduce the quality of drinking water supplies. Because the monetary costs associated with the removal of these compounds can be high, it is impractical for most facilities to continuously treat their raw water. Instead, new tools are needed to help predict when taste and odor events may be most likely to occur. Water quality data were collected between June and October in 2006-2007 from five Kansas (USA) reservoirs in order to develop predictive models for geosmin, a major taste and odor compound; two of these reservoirs were also sampled during specific taste and odor events in December 2006 and January 2007. Lake trophic state alone was not a good predictor of geosmin concentrations as the highest average geosmin concentration was observed in the reservoir with the lowest nutrient and chlorophyll a concentrations. In addition, taste and odor events were not confined to summer months; elevated geosmin concentrations were observed in several reservoirs during the winter. Growth limitation by inorganic phosphorus appeared to be the primary determinant of geosmin production by algal cells in these reservoirs.     

滑坡体低渗透性含水层的虹吸抽水试验方法

由于抽水泵流量远远大于单孔单位涌水量,因而传统抽水试验在低渗透性含水层中"一抽即干",无法形成稳定流.本文利用小直径塑料管代替抽水泵进行了虹吸抽水试验,先进行了3mm和4mm塑料管对比试验,然后采用4mm塑料管,进行二路、四路、六路组合虹吸抽水试验.试验结果表明,多路塑料管的出水能力与低渗透性含水层涌水量匹配,可以形成...     

粘性土层井孔抽水试验的参数识别

粘性土层属于弱透水层,其水流、溶质运移和地球化学过程对于水文地质条件和环境变化具有重要意义.通过抽水试验来获取粘性土原位水力学参数是对粘性土水文地质问题进行研究的必要手段,但由于其渗透性很小,不能采用和常规含水层一样的方法求参.粘性土中的单孔抽水试验与一般含水层中的微水试验具有较大的相似性,因此可以借用微水试验的计算公...