Models for predicting disinfection byproduct (DBP) formation in drinking waters: A chronological review

Disinfection for the supply of safe drinking water forms a variety of known and unknown byproducts through reactions between the disinfectants and natural organic matter. Chronic exposure to disinfection byproducts through the ingestion of drinking water, inhalation and dermal contact during regular indoor activities (e.g., showering, bathing, cooking) may pose cancer and non-cancer risks to human health. Since their discovery in drinking water in 1974, numerous studies have presented models to predict DBP formation in drinking water. To date, more than 48 scientific publications have reported 118 models to predict DBP formation in drinking waters. These models were developed through laboratory and field-scale experiments using raw, pretreated and synthetic waters. This paper aims to review DBP predictive models, analyze the model variables, assess the model advantages and limitations, and to determine their applicability to different water supply systems. The paper identifies the current challenges and future research needs to better control DBP formation. Finally, important directions for future research are recommended to protect human health and to follow the best management practices.     

基于最优传输长度的数字反向传输方案

指出传统的数字反向传输方案对光纤进行补偿时不能得到系统的最小误码率,分析了不同反向传输长度对系统性能的影响。提出了基于最优传输长度的数字反向传输方案,并证明了在最优传输长度处能获得最小误码率。仿真结果表明,该方案能够提高系统性能。     

DBP连续法生产技术

国内DBP消耗量呈逐年上升的趋势,2000年的消耗量为20万t。目前,国内生产装置全部采用间歇法操作,消耗定额高、能耗大、劳动强度大、废料多且污染严重。连续法DBP生产技术的关键是酯化过程的连续化及副产品丁醚的分离。本文对这两个系统进行了全面的研究,实现了DBP生产过程的连续化,开发的新工艺已用于实际过程的扩产改造,结果表明:产品质量稳定,消耗定额低,副产丁醚的浓度可达98％以上。     

表面活性剂对碳化法制备白炭黑的影响研究

在碳化法制备白炭黑的过程中分别选用聚乙二醇6000、十二烷基苯磺酸钠、羧甲基纤维素等三种表面活性剂制备改性白炭黑。参察产品的性能，筛选合适的表面活性剂。     

UV/H2O2降解城市污水处理厂尾水中低浓度DBP的研究

试验研究了UV/H2O2工艺处理模拟城市污水处理厂尾水中低浓度的DBP,考察了工艺参数和水质参数对DBP降解效果的影响。结果表明,单独UV光照或单独H2O2对DBP的降解效果远低于两者的协同作用。DBP的降解效率随着H2O2投加量的增加而增大,随着DBP初始质量浓度的增大而减小,且其光降解速率常数与其初始质量浓度成拟一级反应动力学关系。在DBP初始质量浓度为1～100μg.L-1,H2O2投加量为0.10 g.L-1,UV辐射强度为24.26μW.cm-2的条件下,反应进行30 min后,DBP降解率均可达到90%以上,且pH对其降解效果影响小。UV/H2O2工艺对于浊度低、成分复杂的城市污水处理厂尾水中低浓度的DBP去除率为85%,比去离子水中配制的DBP原水降解率低14%。     

Determination of 2,6-diisopropylnaphthalene (DIPN) and n-dibutylphthalate (DBP) in food and paper packaging materials from US marketplaces

A gas chromatography-ion-trap tandem mass spectrometry procedure was developed for the determination of 2,6-diisopropylnaphthalene (DIPN) and n-dibutylphthalate (DBP) in domestic and imported paper packages and food sold in US marketplaces. The procedure involved ultrasonic extraction with dichloromethane, followed by analysis with the gas chromatography-ion-trap tandem mass spectrometry. Calibration curves for DIPN and DBP were achieved with concentrations ranging from 0.01 to 10 µg ml^?1 and the corresponding r ² values were 0.9976 and 0.9956, respectively. In most of the fortified samples the recoveries were higher than 80% with a relative standard deviation (RSD) <10%. Using this procedure, it was found that less than 20% of the tested domestic packages and more than 60% of the tested imported food packages contained both DIPN and DBP. The concentrations of DIPN and DBP ranged from 0.09 to 20 mg kg^?1 and 0.14 to 55 mg kg^?1, respectively, with most of the DINP and DBP levels lower than 20 mg kg^?1. DIPN was not detected (<0.01 mg kg^?1) in 41 food samples and DBP was only detected in two domestic and four imported food samples with concentrations ranging from <0.01 to 0.81 mg kg^?1.     

原水天然有机物化学特性与消毒副产物关系

原水氯消毒过程中,氯会与水中的天然有机物(NOM)反应,生成三卤甲烷、卤乙酸等消毒副产物(DBPs).为了选择有效的饮用水净化工艺,控制消毒副产物的生成,研究天然有机物的化学特性及与消毒副产物的关系,是十分必要的.在总结NOM相似组分化学分离方法的基础上,概括了不同水源中NOM及各组分溶解性有机砌(DOC)的含量,对消毒副产物的贡献,化学组成以及可能生成DBPs的化学结构.不同水源中NOM及各组分DOC含量不同,相同组分对消毒副产物的贡献也有很大的差别,且NOM各组分的化学组成有一定的重叠,对生成DBPs的化学结构需继续研究.     

DBP生产中回收醇的再利用

在DBP生产中,对需废弃的回收醇进行色谱分析,根据组分特点,找出了一条回收醇重新再利用的方法,通过实践,效果良好。     

TBP-煤油-HNO_3体系的辐解与水解

本文应用气相色谱法测定了TBP-煤油-HNO_3萃取体系中 TBP辐解产物DBP和MBP的生成G值。G_(DBP)值与文献值一致:G_(MBP)值为文献值的～1/3。测定了TBP在 27℃下水解生成DBP的速度常k值。通过表观动力学计算指出,TBP辐解生成 MBP有两个途径。给出了一个TBP 辐解生成DBP和MBP与辐照剂量之间的关系式。     

基于数值模拟的纳污能力计算方法探讨

以邻苯二甲酸二丁酯(DBP)为典型污染物,采用室内水槽试验、数值模拟及野外示踪试验,分析了水体中污染物降解的主要影响因素,研究了流速、含沙量、粒径等因素对污染物降解过程的影响,并将结果与水质模型进行耦合,提出了新的纳污能力计算方法。分别采用该方法以及《水域纳污能力计算规程》和《全国水资源综合规划地表水资源保护补充技术细则》的计算方法,计算了长江武汉段青山工业用水区DBP纳污能力。结果表明,基于数值模拟的纳污能力计算方法可以解决降解系数取值问题,可为更准确地核定水域纳污能力提供技术支撑。