离子色谱法测定瓶装矿泉水中痕量溴酸盐

建立测定饮用水中痕量溴酸盐的离子色谱法,并对北京地区超市瓶装矿泉水进行随机抽样调查。方法采用Di-onex ICS-1000型离子色谱,IonPac AS23阴离子交换柱,Na2CO3/NaHCO3等度淋洗,电导检测器,直接进样,进样体积为500μL。结果离子色谱法测定饮用水中痕量溴酸盐的检出限为0.2μg/L;在1～100μg/L范围内具有良好的线性关系（r=0.9999）;5种不同浓度标准溶液的相对标准偏差（RSD）均小于10%;对北京地区超市16种瓶装矿泉水样品中痕量溴酸盐进行了检测,加标回收率在98%～106%之间,样品检出浓度在1.78～14.49μg/L之间,其中有2种矿泉水样品溴酸盐含量超过了限值（10μg/L）。结论离子色谱法测定饮用水中痕量溴酸盐具有灵敏度高、操作简单、分离效果好、重现性卓越等特点。市售瓶装矿泉水具有一定的致癌危险性,建议相关部门依据新国标要求加强对市售瓶装矿泉水的监测和管理。     

Characterization of bromate-reducing bacterial isolates and their potential for drinking water treatment

The objective of the current study was to isolate and characterize several bromate-reducing bacteria and to examine their potential for bioaugmentation to a drinking water treatment process. Fifteen bromate-reducing bacteria were isolated from three sources. According to 16S rRNA gene sequencing, the bromate-reducing bacteria are phylogenetically diverse, representing the Actinobacteria, Bacteroidetes, Firmicutes, and α-, β-, and γ-Proteobacteria. The broad diversity of bromate-reducing bacteria suggests the widespread capability for microbial bromate reduction. While the cometabolism of bromate via nitrate reductase and (per)chlorate reductase has been postulated, five of our bromate-reducing isolates were unable to reduce nitrate or perchlorate. This suggests that a bromate-specific reduction pathway might exist in some microorganisms. Bioaugmentation of activated carbon filters with eight of the bromate-reducing isolates did not significantly decrease start-up time or increase bromate removal as compared to control filters. To optimize bromate reduction in a biological drinking water treatment process, the predominant mechanism of bromate reduction (i.e., cometabolic or respiratory) needs to be assessed so that appropriate measures can be taken to improve bromate removal.     

葡萄糖氧化酶,颇具前途的溴酸钾替代品

葡萄糖氧化酶具有显著改善面团强度和弹性、提高面包质量的作用。它与其它酶制剂和Vc之间具有协同效应,用于烘焙面包,能获得理想的烘焙效果,同时,葡萄糖氧化酶凭借其天然的优良特性,可作为溴酸钾的一个较为理想的取代物;     

Disinfectant decay and disinfection by-products formation model development: chlorination and ozonation by-products

Comprehensive disinfectant decay and disinfection by-product formation (D/DBP) models in chlorination and ozonation were developed to apply to various types of raw and treated waters. Comparison of several types of models, such as empirical power function models and empirical kinetic models, was provided in order to choose more robust and accurate models for the D/DBP simulations. An empirical power function model based on dissolved organic carbon and other parameters (Empirically based models for predicting chlorination and ozonation by-products: haloacetic acids, chloral hydrate, and bromate, EPA Report CX 819579, 1998) showed a strong correlation between measured and predicted trihalomethane (THM) and haloacetic acid (HAA) formation for raw waters. Internal evaluation of kinetic-based models showed good predictions for chlorine decay and THM/HAA formation, but no significant improvements were observed compared to the empirical power function model simulations. In addition, several empirical models for predicting ozone decay and bromate (ozonation disinfection by-product) formation were also evaluated and/or developed. Several attempts to develop kinetic-based and alternative models were made: (i) a two-stage model (two separate decay models) was adapted to ozone decay and (ii) an ozone demand model was developed for bromate formation. Generally, internal evaluation of kinetic-based models for ozone decay showed significant improvements, but no significant improvements for the simulation of bromate formation were observed compared to the empirical power function model simulations. Additional efforts were performed to reduce the gaps between specific models and their actual application. For instance, temperature effects and configuration of ozone contactors were considered in actual application.     

淋洗液发生器离子色谱测定面粉制品中的溴酸根

建立了淋洗液发生器电导抑制离子色谱测定面粉制品中的溴酸根的方法,采用高容量阴离子色谱柱IonPacAS11HC为分离柱,采用自动淋洗液发生器产生的高纯KOH淋洗,样品经提取,去除部分有机物和氯离子后,进样分析.方法的线性范围广,灵敏度高,重现性好,样品相对标准偏差RSD为4.66%,样品平均加标回收率91.5%-93.6%,检出限为5μg/kg.     

臭氧氧化工艺溴酸盐控制中试研究

通过1m3/h的中试装置研究了臭氧氧化工艺处理引黄水库水时溴酸盐控制技术。结果表明,在臭氧投加量为1.5mg/L时,臭氧氧化后溴酸盐产生量为0.006mg/L,活性炭过滤出水溴酸盐为0.002mg/L;在相同臭氧投加量条件下,降低原水pH、投加高锰酸钾和过氧化氢后溴酸盐生成量分别减少了50%、33%和100%,活性炭后出水中均未检出溴酸盐,同时提高了有机物去除率。     

预臭氧化工艺对消毒副产物影响的生产性研究

通过进行预臭氧化—紫外线联合氯消毒工艺处理高温高藻期滦河水的生产性试验,检测和分析三卤甲烷生成势(THMFP)和卤乙酸生成势(HAAFP)的含量变化情况,研究了整套水处理工艺,尤其是预臭氧化单元对氯消毒副产物(DBPs)的去除效果。同时,研究了甲醛和溴酸盐这两种臭氧化副产物在处理过程中的生成情况。结果表明:在高温高藻期,预臭氧化单元对THMFP和HAAFP的平均去除率分别为12.43%和15.06%,整套工艺对THMFP和HAAFP的平均总去除率分别为39.33%和54.12%,氯消毒副产物前体物得到有效去除;出水中甲醛含量低于50μg/L,溴酸盐的含量小于6μg/L,臭氧氧化副产物得到了有效控制。     

How Bromate and Ozone Concentrations Can be Modeled at Full-Scale Based on Lab-Scale Experiments – A Case Study

This article presents a full-scale modeling study of an industrial ozonation unit for practical application. The modeling framework combines an integrated hydraulic model (systematic network) with a quasi-mechanistic chemical model. Dealing with natural water, the chemical model has to be parameterized, and the parameters calibrated. This was done based on lab-scale experiments. The calibration results showed that the chemical model is able to account for changes in contact time with ozone, pH, temperature, ozone dose, NOM concentration, bromide concentration. Comparison of residence time distributions showed that the hydraulic model accurately reproduces flow conditions. Six sampling points were installed along an industrial ozonation unit of 487 m³ consisting of two baffled tanks in series. Bromate and ozone concentrations were monitored under varying operational process conditions. After the selection of a value for the k_La, simulations were run. Using the lab-scale calibrated models, simulated and experimental data were found in close agreement: 84% of the simulated concentrations for ozone matched measurements (±experimental error), 60 % for bromate. A readjustment of the kinetics of a single reaction (out of 65) showed that seasonal changes in NOM activity may easily be taken into account based on regular concentration measurements (90% of the bromate concentrations were then modeled accurately).     

溴酸钾替代物的原理和途径

溴酸钾对面包品质有着明显的改良作用,在面粉厂以及面包厂都有广泛的应用历史.但随着科技日益发展,越来越多的证据显示溴酸钾作为品质改良剂对人体有着潜在的危害,许多国家已经禁止使用.为维护广大消费者的健康,溴酸钾替代物的研究工作也在不断开展当中.本文主要论述了溴酸钾替代物在面包中的应用原理、替代途径.