饮用水嗅味问题及其分析方法研究进展

近年来,随着生活水平的不断提高,以及水环境的逐渐恶化,饮用水嗅味问题已成为关注的热点。对饮用水中嗅味物质的来源、分类、危害及其分析方法进行了综述,着重从感官分析法、仪器分析法、酶联免疫法(ELISA)以及综合分析法这4个方面介绍了国内外对饮用水嗅味评价及嗅味物质检测分析技术的研究进展,就各检测方法的原理、优缺点及今后的研究方向进行了简要介绍和总结。     

凹凸棒土吸附去除饮用水中典型嗅味物质的研究

饮用水水源中通常存在有致嗅味物质,由于常规饮用水净水工艺对致嗅味物质去除效果不佳,导致饮用水有异嗅异味的问题。试验以水中典型的致嗅味物质二甲基异冰片和土嗅素为嗅味代表物质,研究了凹凸棒土作为吸附剂对嗅味物质的吸附行为,探讨了pH值、凹凸棒土投加量、水力条件、竞争吸附等对凹凸棒土吸附水中嗅味物质的影响。     

饮用水中嗅味问题及其研究进展

综述了我国饮用水中嗅味问题的研究进展,介绍了我国饮用水中嗅味问题现状、水中嗅味物质的来源、致嗅物质的分类及测定方法,重点讨论了典型致嗅物质的去除技术。旨在阐明高锰酸钾-活性炭联用技术、臭氧-活性炭联用技术均能有效地去除水中嗅味、有机物和色度,是饮用水最有力的安全屏障。     

饮用水中嗅味物质去除技术研究进展

饮用水中异嗅异味不仅影响了感官性状,还降低了饮用水水质。介绍了饮用水中的嗅味物质的分类方法和去除技术,特别是常见的两种嗅味物质土臭素和2-甲基异莰醇的典型去除工艺。并分析了吸附处理、化学氧化、生物处理和联用技术的去除效果及优缺点,指出了嗅味物质去除技术的发展方向。     

生活饮用水主要致嗅物质及其处理

随着地表水体的富营养化加剧,使微生物产生的一些致嗅物质进入水体,最终导致生活饮用水异味的产生。本文针对致嗅物质,从其性质、来源、检测及去除四个方面加以概述,意在为提高生活饮用水品质提供科学合理的建议。     

感官气相色谱对水中不同化合物嗅味特征的同步测定

嗅味是饮用水中最为关注的水质问题之一,确定不同物质的嗅味类型和嗅阈值等是有效解决嗅味问题的基础。文中以6种硫醚类物质为对象,基于感官气相色谱(GC-O)对同步测定其嗅味类型和嗅阈值的可行性进行了研究。基于GC-O测定时采用1μL的注射体积、3.0 mL/min的柱流速、2∶1的质谱检测器与嗅闻仪分流比,利用10名以上闻测员,通过Logistic回归或几何平均的方式对嗅阈值和嗅味特征进行测定。6种硫醚类物质气相中的嗅阈值分别为0.033(二甲基三硫醚)、0.15(二异丙基硫醚)、0.40(甲硫醚)、0.72(二甲基二硫醚)、0.84(二乙基二硫醚)、1.70 ng/L(二异丙基三硫醚);“臭味”“臭鸡蛋味”“沼泽味”“酸臭味”是硫醚类物质的主要描述;参加过嗅味评价的人员组成的暴露组嗅阈值浓度更低,未暴露组对硫醚的嗅味特征描述更多样化。该方法为同时测定不同物质的嗅味特征提供了可能,对于进一步实现水中嗅味污染的快速评估和控制具有重要意义。     

饮用水中土腥味和霉烂味的去除方法研究

在水处理过程中,常规工艺难以去处污染原水中的土腥味和霉烂味,产生这些嗅味的化合物主要是土味素(Geosmin)和2-甲基异冰片(MIB)。采用固相微萃取(SPME)和色质联机分析技术分析水中的土味素和2-甲基异冰片含量。实验结果表明,高锰酸钾和粉末活性炭(PAC)联用能彻底地去除水中的异嗅味,其机理是通过氧化和吸附作用去除有机物,是一种高效适用的饮用水除嗅味技术。     

水体中微囊藻毒素检测方法研究进展

蓝藻水华会向水体中释放大量的微囊藻毒素,对水体生物及饮用水安全构成很大的威胁。综述了国内外藻毒素的分析方法,包括生物检测法、物理化学检测法、生物化学检测法和分子生物学检测法,指出了各种检测方法的优缺点,评述和展望了研究方法的未来发展趋势。     

高级氧化技术去除水中嗅味物质土臭素及2-甲基异冰片的研究现状

概述了饮用水处理中土臭素(GSM)、2-甲基异冰片(MIB)的来源、嗅味特性及应用高级氧化处理技术的必要性,并揭示了其中反应活性物质的作用机理。重点介绍了应用臭氧组合氧化工艺(O3/H2O2、UV/O3、UV/O3/H2O2、臭氧催化氧化)、光催化、超声波来降解GSM和MIB。探讨了试验过程、梳理试验结论,并对部分试验的效果进行对比。各工艺在去除嗅味物质的过程中生成的TPs(苯甲醛类物质),其致嗅特性,毒理特性尚不明确,仍需进一步研究定性。     

石蜡嗅味定量监控方法探讨

石蜡嗅味问题已经成为制约全炼蜡生产的瓶颈,但现有嗅味测定的标准方法为定性方法,受人为影响因素大,迫切需要找到一种定量监控石蜡嗅味的分析方法来指导生产。本文尝试利用顶空法测定石蜡中的挥发性物质,并用挥发性物质预测石蜡嗅味。实验证明甲苯作为典型的嗅味标志物,其含量与嗅味有一定的对应关系,当甲苯控制在5mg/kg以下时,嗅味基本都能达到1.5级及以下,达到1.0级的比例能达到80%,测定甲苯含量可以作为监控石蜡嗅味的一种有效的辅助手段。     

滆湖水源水微污染处理试验研究

滆湖水源受到污染,自来水出现异味。投加高锰酸钾、折点加氯未能消除。经臭氧氧化、颗粒活性炭吸附处理,可有效去除异味,同时降低ＣＯＤ、ＵＶ２５４吸光值。经臭氧氧化、活性炭吸附处理,每吨水的制水成本增加０．２４元。     

城市饮用水产生嗅味的原因及控制技术研究

由于富营养化造成的水体嗅味问题日益严重,而常规水处理方法不能有效去除水体嗅味。研究表明,应根据嗅味水源水质,在常规处理技术上结合诛夏处理技术,才能有效去除水体嗅味。     

Rationales for Multiple Stage Ozonation in Drinking Water Treatment Plants

Starting in the early 1970s, the application of ozone for drinking water treatment began to evolve from primarily single-purpose, single-stage use for disinfection, taste and odor control or iron and manganese oxidation, to multipurpose uses of ozone. As a result, most of the newer drinking water treatment plants have installed two- and even three-stages of ozonation. in order to maximize the technological benefits of ozone and to minimize the costs involved.     

Reviewing the 20 Years of Operation of Ozonation Facilities in Hanshin Water Supply Authority with Respect to Water Quality Improvements

More than 20 years have passed since the introduction of advanced water treatment with ozonation and granular activated carbon in the Hanshin Water Supply Authority. Significant improvements have been achieved in eliminating taste and odor compounds in water and in suppressing the formation of disinfection by-products. Regarding the bromate ion, we have managed to suppress its formation by keeping the residual ozone concentration and pH low.     

Application of Combined Ozone–Hydrogen Peroxide for the Removal of Aromatic Compounds from a Groundwater

Nitro and chlorobenzene compounds, which are widely used in dye industries, have been associated recently with groundwater contamination. Because of their potential toxicity and for taste and odor considerations, three main actions were undertaken to solve the problem. First, to follow the advance of pollution toward the wells, samples were collected automatically and analyzed using GC-MS. Results indicate that o-chloronitrobenzene was the main pollutant in concentrations ranging from 10 to 2000μg/L. Second, to monitor the drinking water quality, an on-line spectrophotometer was used to measure the optical density at 254 nm at the inlet and outlet of the plant. Third, the feasibility of using the O₃/H₂O₉ combination was determined at a 450 L/h pilot plant. Reduction of concentrations of chloronitrobenzenes from 1900 μ/L to less than 20 μg/L could be reached by the application of 8 mg O3/L and 3 mg H2O9/L with a 20-minute contact time. To avoid an eventual bacterial egrowfn in the network due to biodegradability of the oxidation by-products, sand and GAC filtration were tested after oxidation. An evaluation of the costs of these different treatments is also presented.     

Which plastic package has the lowest contribution to taste and odor?

Although plastics have made significant inroads in the packaging area, little work has been done in the U.S. to evaluate their effect on the taste and odor of the package contents. This is especially relevant for food, beverage, liquor, and bottled water. Rohm and Haas contracted with an independent consulting firm, which uses a professional panel familiar with the effects of packaging, to assess the sensory impact of different plastics on the taste of water. Four types of plastics were tested: polyvinyl chloride (PVC), high-density polyethylene (HDPE), polycarbonate (PC), and polyethylene terephthalate (PET). Two forms of each polymer were evaluated, bottles and plaques, which were aged in water for four weeks at room and elevated temperature (120°F). The professional panel evaluated the taste and odor of the water on a numerical intensity scale and characterized any observed effect with words. The numerical rating permitted the effects of the plastic materials to be compared directly. PVC had the lowest contribution to taste and odor of all of the plastics. PVC was followed by PET and then PC and HDPE. Therefore the two current packaging materials, HDPE and PC, were not the best! This implies that water and other taste-sensitive products could be more appealing if packaged in appropriately formulated PVC.     

An Automated Procedure for Monitoring the Effectiveness of Ozonation Processes

Measurement of the 254 nm absorption of organics was chosen for monitoring the ozonation processes used to remove organic matter in a drinking water because of its ability to reflect the performance of ozonation. Ozone flow rate, ozone concentration in the gas (phase, addition of H₂0₂ and seasonal variations on kinetics of the reduction of UV absorption were varied and the efficiency of ozonation was determined. For several yearst ozonation has been applied at different points in potable water treatment. The original goal of ozonation was reduction in taste and odor and disinfection without by products of organoleptic concern (e.g.. chlorophenols). Ozone also has the capacity to oxidize organic matter.     

Pilot Testing Of Trace Metals Removal With Ozone At Snowbird Ski Resort

A pilot study at the Snowbird Ski Resort in Utah evaluated feasibility of ozonation replacing chlorine and sulfur dioxide for oxidation of iron and manganese in groundwater. Ozonation also was tested for the removal of lead and cadmium, occurring at concentrations exceeding drinking water Maximum Contaminant Levels. An ozone dose of 2 mg/L, contacted with the water for 1 minute prior to filtration, was selected as optimum for iron and manganese removal from 0.4 mg/L and 40 μg/L, respectively, to below detection limits. Lead, copper, and arsenic also were removed to below detection limits. The removal of cadmium and zinc improved when ozone was contacted for 10 minutes. With metals removal through ozonation and filtration, taste and odor enhancement also were reported.     

Ozonation at the 900 cfs Los Angeles Water Purification Plant

In 1979. the California Safe Drinking Water Act established a new turbidity limit of 0.5 turbidity unit for drinking waters. To meet this new standard at the Owens River Aqueductplantin Los Angelesi aprocessinvolvingpreozonation and direct filtration was tested and selected. In addition to providing water which meets the required turbidity standard, the ozone process reduces THM levels by about 50%, allowsfiltrationrates of 15 gpm/ft², reducescoagulation requirements, increases the removal of organics, thus reducing final chlorination requirements, and provides the most cost–effective reduction of levels of taste, odor, and color. The new Los Angeles water treatment plant will be on–line in 1986.     

光催化技术在水处理中的应用研究进展

光催化技术在水处理领域的应用,既可以提高水质安全,也可以缓解全球能源和水资源短缺问题,是一项具有广泛应用前景的技术。本文首先介绍了光催化技术的基本原理及常用光催化剂的特点,综述了光催化剂技术在饮用水和废水处理应用方面的研究进展及发展方向,重点介绍了光催化技术在饮用水中的除嗅、消毒,在染料废水、含油废水、制药废水、催化还原重金属离子、养殖废水、焦化废水方面的应用,为类似污染水质的处理提供了的参考依据,最后对光催化技术及光催化剂的发展进行了展望。