不同工艺对饮用水消毒副产物的影响

目前最常见的消毒方式是液氯和次氯酸钠消毒,比较二者消毒的优劣,建立离子色谱法来测定不同消毒剂下的亚氯酸盐、氯酸盐以及溴酸盐含量。试验结果表明:臭氧、次氯酸钠消毒所产生消毒副产物的量高于液氯消毒,水源水中氯化物、溴化物的含量亦会影响出厂水中消毒副产物的量。     

有效控制水中消毒副产物氯酸盐和亚氯酸盐

某水厂采用二氧化氯对饮用水消毒,当出厂水二氧化氯为0.12mg/L时,按照《生活饮用水卫生标准》(GB5749-2006)评价,其氯酸盐和亚氯酸盐均超标。为了查明氯酸盐、亚氯酸盐超标原因,本论文对水厂的消毒工艺进行调整,实现水厂出厂水和管网水二氧化氯、氯酸盐和亚氯酸盐达标。     

离子色谱法测定饮用水中亚氯酸盐、氯酸盐和溴酸盐的残留量

本文建立了饮用水中亚氯酸盐、氯酸盐和溴酸盐的离子色谱检测方法,并对方法中的线性、精密度、加标回收率等参数进行了考察。实验结果表明,亚氯酸盐、氯酸盐和溴酸盐在4.00～60.0μg·L~(-1)浓度范围内呈良好的线性关系,相对标准偏差均小于2%(n=6),加标回收率在92.0%～104.0%之间,符合样品分析质量要求。本方法操作简便,实用性强,灵敏度高,测定结果准确可靠,适用于水中亚氯酸盐、氯酸盐和溴酸盐残留的监测。     

离子色谱法测定水中5种消毒副产物和6种阴离子

利用新型离子色谱柱AS23柱对水中5种消毒副产物:二氯乙酸(DCAA)、三氯乙酸(TCAA)、亚氯酸盐(C102)、溴酸盐(BrO3)、氯酸盐(ClO3)和6种常见阴离子:F-、CI-.NO-2;、Br-、NO-3、SO2-4进行检测,通过实验研究,测试方法对饮用水中11种被测物的最低检测限为0.42～15.55ug/L.加标回收率为89.30%～115.12%,适合于同时检测饮用水中消毒副产物和常见阴离子.     

离子色谱法测定水中5种消毒副产物和6种阴离子

利用新型离子色谱柱AS23柱对水中5种消毒副产物：二氯乙酸（DCAA）、三氯乙酸（TCAA）、亚氯酸盐（ClO2）、溴酸盐（BrO3）、氯酸盐（ClO3）和6种常见阴离子：F^-、Cl^-、NO2^-、Br、NO3^-、SO4^2-进行检测,通过实验研究,测试方法对饮用水中11种被测物的最低检测限为0．42～15．55μg／L。加标回收率为89．30％～115．12％,适合于同时检测饮用水中消毒副产物和常见阴离子。     

离子色谱法测定水中典型的消毒副产物和溴离子

论文采用淋洗液在线发生离子色谱法测定水中的五种消毒副产物和溴离子。淋洗液自动发生装置在线产生高纯度KOH,配合阴离子捕获柱CR-ATC使用,大幅度降低了本底电导(0.2μs左右),对水中痕量亚氯酸盐、氯酸盐、溴酸盐、二氯乙酸、三氯乙酸以及溴酸盐的前驱物溴离子进行准确定性定量分析。KOH淋洗液的梯度淋洗,明显改善了6种目标离子与其他阴离子的分离效果,使整个检测过程简便、高效,本方法对亚氯酸盐、氯酸盐、溴酸盐、二氯乙酸、三氯乙酸、溴离子的检出限分别为0.46μg/L、0.72μg/L、0.50μg/L、0.81μg/L、0.68μg/L、0.51μg/L;加标回收率在88%～111%;精密度在0.66%～5.90%;具有良好的线性。     

次氯酸钠与二氧化氯联用降低消毒副产物的应用探讨

为了解决自来水厂应用二氧化氯导致的消毒副产物亚氯酸盐、氯酸盐超标问题,对亚氯酸盐生成量与二氧化氯投加量相关性进行了测定分析,开展了以次氯酸钠替代二氧化氯消毒,同时保留二氧化氯预氧化生产性实验。结果表明,亚氯酸盐生成量与二氧化氯投加量显著相关,因此,采用二氧化氯预氧化与次氯酸盐消毒联用,既保证了水质消毒效果,又使水中亚氯酸盐的浓度大幅度降低并稳定达标。     

离子色谱法测定水中微量卤化物及卤素含氧酸盐

本文建立了利用离子色谱快速测定水中微量卤化物及卤素含氧酸的方法，该方法一次进样可在25分钟内同时测定氟化物、氯化物、溴化物、亚氯酸盐、氯酸盐、溴酸盐、亚硝酸盐、磷酸盐和硫酸盐等十个指标，方法精密度好，准确度高，各离子的检出限均达到10μg／L以下，加标回收率均在87％－103％之间，取得了较为满意的结果，能够满足饮用水消毒产生的微量卤素含氧酸等无机副产物的宣需要。     

二氧化氯应用于水箱二次供水安全消毒研究

采用消毒剂二氧化氯(ClO2)进行二次供水水质消毒试验研究,考察了ClO2投加量、氨氮、CODMn和pH对ClO2的衰减及氯酸盐和亚氯酸盐消毒副产物生成的影响,并建立了氯酸盐(ClO3-)和亚氯酸盐(ClO2-)生成质量浓度的预测经验模型。结果表明,当原水CODMn<4.20 mg/L、氨氮的质量浓度<0.582 mg/L、pH在6.5～8.5、水中投加0.05mg/L的ClO2、HRT为48 h时,一定的液位降泵启动,消毒副产物在监测12 h内不超过GB 5749-2006的规定,并在水箱中基本检测不到微生物的存在。相同条件下,若ClO2投加量大于0.70 mg/L时,消毒副产物则可能超标。     

双抑制离子色谱法同时检测生活饮用水中9种阴离子

以A Supp7为分析柱,碳酸盐溶液为淋洗液,电导检测器,化学抑制(MSM)和二氧化碳抑制(MCS)连续抑制,建立了一次进样同时测定生活饮用水中6种常见阴离子(F~-、Cl~-、NO~-_2、NO~-_3、PO■、SO■)和3种无机消毒副产物(BrO~-_3、ClO~-_2、ClO~-_3)的分析新方法,9种阴离子在21 min内完全出峰。9种离子分别在各自线性范围内呈良好的线性关系,相关系数r均0.999,检出限分别为0.16～11.70μg/L。对4个自来水厂出厂水进行检测,发现4个水厂均有氯酸盐检出,亚氯酸盐和溴酸盐均未检出。结果表明,该方法简单、快速、灵敏度高、实用性强,可以有效地监控水中消毒副产物的变化以及无机污染物的变化。     

电位滴定法区分测定水中微量ClO2,Cl2,ClO2-及ClO3-的研究

利用自动电位滴定仪分别测定了NaClO2固体质量浓度为20mg/L，10mg/L，5mg/L，2.5mg/L，，1mg/L和NaClO23（与盐酸反应）质量浓度为20mg/L,10mg/L，5mg/L，2.5mg/L，，1mg/L的水样，分别求出其回收率及检出限。试验表明电位滴定法能在5mg/L以上质量尝试快速准确的区分测定ClO2，Cl2，ClO2^-和ClO3^-。     

Formation of chlorite and chlorate from chlorine dioxide with Han river water

This study was designed to elucidate the behavior of chlorine dioxide in drinking water systems. Furthermore, the factors that influence the formation of chlorite, chlorate in terms of reaction time, concentration of chlorine dioxide, pH, temperature and UV irradiation were experimentally reviewed. At 20 ‡C, pH 7, 70–80% of chlorine dioxide injected was converted to chlorite and 0–10% of that was transformed into chlorate within 120 min with 2.91 mg/L of DOC. The amount of chlorite formed also increased when pH and temperature increased. As DOC content increased, the residual chlorine dioxide decreased but the amount of chlorite and chlorate were increased. These experiments revealed that chlorate was a dominant by-product under UV irradiation. The models that were obtained by the regression analysis for the formation of chlorite and chlorate from chlorine dioxide with Han River water are as follows: Chlorite (mg/L)=10^-2.20[ClO₂]^0.45[pH]^0.90[temp]^0.27[TOC]^1.04[time]^0.20, Chlorate (mg/L)=10^-2.61[ClO₂]^1.27[pH]^-0.50[temp]^1.28 [TOC]^0.31[time]^0.12     

新型消毒剂-ClO_2的制备方法及应用现状

本文详细地介绍了二氧化氯的制备方法和现有的几种二氧化氯制品及其应用     

Product and by-product formation in laboratory studies on disinfection electrolysis of water using boron-doped diamond anodes

Boron-doped diamond (BDD) electrodes were studied with respect to the formation of inorganic by-products in water electrolysis. Experiments in non-divided cells were performed with systems containing sulphate, chloride, chlorite, chlorate and nitrate ions. Discontinuous experiments in thermostated cells with rotating disk diamond anodes and expanded mesh IrO₂ cathodes were carried out at 20 °C. Current density was varied between 50 and 300 A m⁻². Ion chromatography was mainly used for species detection.

It was not possible to demonstrate the decomposition of sulphate although a slight tendency seems to exist in some experiments. Hydrogen peroxide is one of the anodic and cathodic by-products. Active chlorine is detectable at higher chloride concentrations compared with the use of mixed oxide anodes (MIO). One reason for this is the reaction of formed chlorine with ozone or hydrogen peroxide. Chlorate can be formed electrolysing chloride, hypochlorite and chlorite solutions. Perchlorate formation was detected. Cathodic processes are responsible for the formation of nitrite ions and ammonia. If chlorine is present, the formation of monochloramine is one possible side reaction. Results show that the processes are very complex. Reaction spectra may vary from case to case. Perchlorate formation is a high risk in drinking water treatment.     

Minimization Of Disinfection By-Products Formation In Water Purification Process Using Chlorine Dioxide — Case Studies

The formation of the by-product chlorite after using chlorine dioxide for the disinfection of drinking water depends on the quantity of the organic matter dissolved in the water. A further decisive factor for the chlorite formation is the level of residual free chlorine dioxide. The chlorine dioxide demand decreases by application of activated carbon filtration, especially after the use of a combination of ozone and activated carbon treatment of the water. Nevertheless, higher chlorine dioxide residuals are a source of chlorite and chlorate formation. The concept of the “Minimum Chlorine Dioxide Dosage (MCDD)” is developed in order to give a clue to the water companies for an optimized chlorine dioxide dose without compromising the disinfection efficiency. By application of the MCDD, the residual level of chlorine dioxide is focused to 0.05 mg/L after 0.5 h contact time. In the range of the MCDD the ratio of the chlorite formation and the chlorine dioxide demand is nearly independent of the level of DOC.     

陕西某地区饮用水中低浓度重金属的测定及健康风险评价

测定12种生活饮用水样本中的铁、锌、铜、铬、铅、镉6种重金属的浓度,并应用美国环保局推荐的健康风险评价模型对这12种水样中的重金属引起的健康风险做了初步评价。结果表明,在12种生活饮用水中,6种重金属的浓度分别为Fe(0.554 5~2.057 3)×10-4mg/L,Zn(0.002 7~0.455 4)mg/L,Cu(0.002 0~0.021 0)mg/L,Cr(0.001 6~0.010 0)mg/L,Pb(0.008 0~0.014 0)mg/L,Cd(5.217~12.17)×10-5mg/L,通过饮水途径所致健康风险中,4#样的健康风险最高2.13×10-4/a,11#样的健康风险最低2.5×10-6/a。     

漏氯吸收液中氯化亚铁的两种检测方法的探讨

液氯泄露是自来水厂重大安全事故之一,因此,漏氯安全装置成为上级主管部门和水厂安全生产监查的主要项目。中山市稔益水厂安装的是氧化还原型漏氯安全吸收装置,装霞内的氯气吸收液主要成分是氯化亚铁。水厂规定对该装置的氯化亚铁浓度进行定期检测,频率为每月一次。因《生活饮用水标准检验方法》中没有氯化亚铁的测定方法,因此,氯化亚铁的检测需参考《生活饮用水标准检验方法》铁的检测方法以及《工业氯化铁国家标准》的检测方法,通过对两种氯化亚铁的检测方法进行对比分析,找出最适合的方法作为本水厂的日常检测方法。     

水煤浆变换系统材料失效情况总结及应对措施

水煤浆变换系统不锈钢管线及设备多次发生材质失效,对此开展全面失效分析,并通过材质升级、风险分析及安全评定、声发射在线监测等手段,保证装置安稳长运行。     

Pre–ndintermediate Oxidation Of Drinking Water With Ozone,Chlorine And “Chlorine Dioxide

With the application of chlorine gas in drinking water treatment processing after the turn of this Century, great success was achieved. With the advance of analytical techniques in the field of trace matter, Rook (1)as well as Bellar, Lichtenberg and Kroner (2) succeeded in 1974 to establish the presence of chloroform and other chlorinated compounds in treated drinking water, namely as the result of chlorination. During tests to minimize the problems of chloroform, of chlorite and chlorate by the simultaneous addition of chlorine andchlorine dioxide, it was discovered that already a small dosage of chlorine dioxide was sufficient to reduce drastically the formation of chloroform andother trihalomethanes. The aimof future treatment techniques in Zurich is the preoxidation with ozone in place of chlorine and chlorine dioxide. Considering the mode of effect of the various oxidizing agents and the longer flow time through the biological activated carbon filters (asa result of the ozonation), ozone is – according to studies made by Grob and the Zurich Water Supply with ozonized Lake Zurich water – the most economical oxidation process with the best effect, i.e., without formation of toxic or carcinogenic substances. The pre– and/or intermediate oxidation with ozone surely will be the right way in the foreseeable future.     

饮用水消毒的健康风险分析及评价

利用健康风险评价的基本理论,分析比较了各种常用饮用水消毒剂的使用对人体健康的影响,从危害鉴别、暴露评价、剂量反应分析及风险表征等各个环节讨论了饮用水处理中消毒剂使用对人类产生的健康风险,并对如何管理控制饮用水消毒带来的健康风险提出了建议。