Removal of natural organic matter in a typical south-China source water during enhanced coagulation with IPF-PACl

Systematic investigation on enhancing removal of natural organic matter （NOM） using inorganic polymer flocculant （IPF）, polyaluminum chloride（PACI） and polyacrylamide（PAM） was performed in a typical south-China source water. Enhanced coagulation and applying polymer flocculant-aid were compared through jar tests and pilot tests. Raw water and settled water were characterized and fractionated by resin adsorption. The results show that DOC composes major part of TOC. The DOC distribution keeps relatively stable all around the year with typical high amounts of the hydrophilic matter around 50%. The distribution between HoB, HoA and HoN varies and undergoes fluctuation with the year round. During the summer season, the HoN becomes gradually the major part in hydrophobic parts. PACI with the species being tailor-made shows little pH effect during coagulation. The enhanced coagulation dosage for PACI could be 4.5 mg/L for the typical source water. The highest TOC removal achieved 31%. To be economically, 3 mg/L dose is the optimum dosage. Although hydrophilic fractions of NOM of both treatment strategies are removed about 30%, NOM causing UV254 absorbance were well removed（about 90%）. Hydrophobic bases and acids fractions are much more removed under enhanced conditions. The hydrophilic fraction could be better removed using PAM, the polymer coagulant aid.

Invertebrate community characteristics in biologically active carbon filter

Biologically active carbon （BAC） system was set up in a water plant of South China during January to December 2007,to study the invertebrate community characteristics of BAC filter.Thirty-seven invertebrate species were found,of which 28 belonging to rotifers.Filter operation could lead to an output of invertebrates in high abundances with the filtrate,and the maximum density could reach 5608 individuals/m 3.Average abundances in the effluent water increased in 27-33 folds in comparison to the influent water during the sampling period.Invertebrate community succession had the following trend：filter-feeding animals → small benthic invertebrates → large benthic and resistant invertebrates.Abundances of large-sized invertebrates （copepod adult and oligochaete） at bigger-media column were significantly higher than that at small-media column.The results implied the abundant species diversity of invertebrate in BAC filter.The relationship between invertebrate and biofilm still remain to be studied in detail.

Preozonation of bromide-bearing source water in south China

The effectiveness of preozonation was evaluated on treating a bromide-bearing dam source water in south China through batch-scale experiments. Preozonation at ozone doses of 0.5-1.0 mg/L （at ozone consumption base） enhanced total organic carbon （TOC） removal through coagulation, and resulted in an almost linear reduction of ultraviolet absorbance at 254 nm （LW2s4）. The removals of TOC （after coagulation） and UV254 at the ozone dose of 1.0 mg/L were 36% and 70%, respectively. Preozonation at an ozone dose between 0.5 and 1.0 mg/L resulted in the removal of disinfection byproducts formation potential （DBFP） including trihalomethane formation potential （THMFP） and haloacetic acid formation potential （HAAFP） for about 50%. The removals of THMFP and HAAFP decreased with the further increase of ozone dose. Ozonation of bromide-bearing water （bromide concentration, 34 μg/L） produced a bromate concentration under the detection limit（2μg/L） at ozone doses 〈1.5 mg/L. However, bromate 〉10μg/L could be produced when the bromide concentration was increased to 96 μg/L.

Flocculation control study based on fractal theory

A study on flocculation control based on fractal theory was carried out. Optimization test of chemical coagulant dosage confirmed that the fractal dimension could reflect the flocculation degree and settling characteristics of aggregates and the good correlation with the turbidity of settled effluent. So that the fractal dimension can be used as the major parameter for floc-culation system control and achieve self-acting adjustment of chemical coagulant dosage. The fractal dimension flocculation control system was used for further study carried out on the effects of various flocculation parameters, among which are the dependency relationship among aggregates fractal dimension, chemical coagulant dosage, and turbidity of settled effluent under the conditions of variable water quality and quantity. And basic experimental data were obtained for establishing the chemical coagulant dosage control model mainly based on aggregates fractal dimension.

CO_(2)应用于中小型水厂原水pH值调控生产性试验

针对水源水pH升高给净水工艺带来的水质风险,以调控水体pH为目的,保障水质安全为目标,在深圳市上南水厂利用CO_(2)释放高效混合碳酸制备系统投加CO_(2)气体,应对原水pH异常升高问题。试验表明,原水投加CO_(2)后,反应pH值基本维持在7.40~7.80,滤后水耗氧量去除率提升10%左右,浑浊度基本维持在0.12 NTU左右,制水成本为0.008元/m^(3),出水2-MIB浓度低于标准。运行效果显著,水质保障能力提升,制水成本较低,对环境无污染,为同类型原水的大型水厂应用CO_(2)气体提供数据参考。

CO_(2)-石灰联用技术在水厂低硬度原水处理中的应用及成效

受地理位置影响,珠江下游低硬度、低碱度原水对给水厂出水水质及管网稳定带来显著影响,对供水安全带来潜在风险。针对这一问题,深圳某水厂基于低硬度水再矿化理论基础,总结再矿化工程实践经验,建立低硬度水再矿化评价标准,制定CO_(2)-石灰联用技术再矿化工程改造措施,并通过优化再矿化试剂投加量,取得较为显著的效果。该实践成效主要表现为:在原水水质硬度较低、化学稳定性较差条件下(总碱度<18.5 mg/L CaCO_(3),CCPP约为-28.29),CO_(2)-石灰联合投加后,出厂水pH值由原来的7.14提高至7.68,碱度由15 mg/L提高至75 mg/L,钙离子由31 mg/L提高至87 mg/L,管网沿线取样点水质pH值平均提升0.2,总铁含量显著下降,由原来的0.02~0.72 mg/L稳定在0.20 mg/L左右,管网水质明显改善。同时,管网水的化学稳定性显著改善,LSI和CCPP分别提升至0.5~1.0和2~12,由原来的严重腐蚀倾向转化为结垢倾向。

Controlling of crustacean zooplankton reproduction in biological activated carbon (BAC) filters by strengthen operation and management of conventional process

To counter the mass reproduction and penetration of crustacean zooplankton in Biological Activated Carbon(BAC)filters which may result in the presence of organisms in potable water and water pollution,this paper analyzed the factors affecting organisms' reproduction in BAC filters.A comparative study was performed on the density and composition of crustacean zooplankton of the concerned water treatment units of two advanced water plants(Plant A and B)which with the same raw water and the same treatment technique in southern China.The results obtained show that the crustaceans' density and composition was very different between the sand filtered water of Plant A and Plant B.which Harpacticoida bred sharply in the sediment tanks and penetrated sand filter into BAC filters was the primary reason of crustaceans reproduce in BAC filters of Plant A.For prevention of the organisms reproduction in BAC,some strengthen measures was taken including pre-chlorination,cleaning coagulation tanks and sediment tanks completely,increasing sludge disposal frequency to stop organisms enter BAC filters,and the finished water quality was improved and enhanced.

Suspended particle effects on ClO_2/ultraviolet light combined disinfection of effluent

The concentration of suspended solids of effluent often varies in a wide range, therefore the dose of ultraviolet light （UV） in disinfection process needs to be adjusted to meet the disinfection criterion at a high frequency, and the desired disinfection effect is difficult to be ensured. The particles size and particle-associated fecal coliform （F.C.） contribution, and their influence on UV disinfection were investigated when ClO2 and UV combined disinfection process was used. The results showed that suspended solids content had a major impact on UV disinfection efficiency, especially the large particle size fraction. Particles （D〉10μm） associated F. C. were difficult to be disinfected and were the main part of the railings of F.C. inactivation curve. Pre-ClO2 oxidation could reduce the number of particles in effluent, and make large particles decrease to small ones. Therefore, the influence of particles on UV disinfection could be reduced after pre-ClO2 oxidation, and the resistance ability to particle loadings of combined process was enhanced. Moreover, the combined process has a lot of advantages, such as low toxicity, low operational/maintenance costs; it is also convenient to be established in the existing wastewater plant or the new planned one.

Impact of Suspended Particles and Enhancement Techniques on Ultraviolet Disinfection of a Secondary Effluent

The concentration of suspended solids in the secondary effluent often varies widely, leading to frequent adjustment of the UV dosage to meet the disinfection criterion. In addition, a desired disinfection rate is difficult to achieve sometimes. The authors studied the particle size distribution, contribution of particle-associated Fecal Coliform (F.C.), and their influences on UV disinfection. A combined disinfection process (chlorination with a subsequent UV disinfection) was tested to improve the disinfection effect. The results indicated that the content of suspended solids, especially that of large particles, has a strong impact on UV disinfection efficiency; D>10 μm particles associated F.C. are difficult to be disinfected and are the main part of the tailings of F.C. inactivation curves. Pre-chlorination could decrease the number of particles in the secondary effluent and transform the large particles into small ones, reducing the influence of particles on UV disinfection and enhancing the resistance ability of the combined process to particle loading.

深圳沙河水质净化厂及3#调蓄池工艺设计要点及特点

沙河水质净化厂设计规模为旱季10万m^(3)/d,雨季额外处理10万m^(3)/d初期雨水,3#调蓄池设计规模为15.3万m^(3)。污水及初期雨水处理采用预处理+多段厌氧-好氧(AO)+二沉池+磁混凝高效沉淀池+精密过滤+紫外消毒的工艺,出水水质执行深圳市地方标准《水质净化厂出水水质规范》(DB 4403/T 64—2020)B级标准,其中总氮(TN)≤8 mg/L。污泥处理采用离心浓缩+低温热干化工艺,处理后含水率≤40%。作为国内首个将水质净化厂与初期雨水调蓄池深度融合的全地下式水污染治理综合体,项目采用多段AO耦合“3W法”(Wet-Weather-Wastewater法),并以此为核心提出了一种实现大规模污水及初期雨水高标准协同处理的系统解决方案,且无需大幅度增加污水处理设施体量、投资和运行成本。

T型氧化沟应急提标改造的探索与实践

以某水质净化厂传统T型氧化沟为研究对象,从技术改造和运行优化的角度探索T型氧化沟出水提标的可行技术措施,充分挖掘老旧生产设施运行潜力。该技术措施具有投资省、耗时少的优势,并且整个实施过程中可以不停产、不减产。实际运行测试和检验结果证明,该技术措施能够较好地解决过渡期出厂水应急提标问题,为早期采用传统T型氧化沟工艺的城镇污水厂应急提标积累技术经验并提供参考方案。

深圳市典型小区供水水力水质模型建设与应用

文章选择深圳市两个经过优质饮用水改造和远传水表安装的典型居民小区,通过小区供水管网与爬墙立管的拓扑绘制、用户水表挂接、用水量分配和用水模式设置、监测和校核数据设置、二供水泵曲线提取、边界条件设置等关键问题研究,建立起楼宇水力和水质模型。经过多点、连续和多时段实测数据的比对校核,使模型达到较好的精度。在此基础上,开展小区用户风险模拟、快速风险评估、二供运行优化等应用。该研究为探索小区模型的建设和应用提供了基础,初步形成小区水力、水质特征研究和评估的理论与方法。

MBBR耦合多段AO工艺在大型市政污水处理厂的运行初探和实践成效

新建城市污水处理厂或提标改造老旧污水处理厂普遍存在出水水质差、污染物负荷与占地面积等不可调和的矛盾,基于纵向扩大池容会增加建设成本、高负荷运行具有超标风险,因此,急需一种污泥/容积负荷高、运行稳定、操作简单的污水处理新技术。对此,某大型市政污水处理厂利用移动床生物膜反应器(MBBR)泥膜共混技术提高生化池有效污泥浓度、实现功能微生物的强化和富集,耦合多段AO工艺,经历雨/旱、夏/冬季,已稳定运行227 d,当进水COD_(Cr)、氨氮、TN质量浓度分别为277.97、34.92、45.95 mg/L,对应出水质量浓度分别降低至12.68、0.33、7.55 mg/L,MBBR挂膜前后的氨氮污泥负荷为0.011、0.015 g氨氮/(g MLSS·d)、TN污泥负荷为0.014、0.020 g TN/(g MLSS·d)。系统稳定运行期间,好氧Ⅰ段氨氮硝化速率为7.27 mg/(L·h)、缺氧Ⅰ段NO-3-N还原速率为3.48 mg/(L·h)。结果表明,通过负载微生物和游离污泥的交互作用,寻求复杂微生物群落功能的强化和调控,可以设计出更加合理、高效的污水处理新工艺。

高有机分污泥离心脱水效果提升的生产性试验研究

当前,环境保护法律法规对城市水质净化厂污泥含水率的要求日益严格。离心脱水工艺处理高有机分污泥时,含水率稳定达标存在困难。以某水质净化厂离心脱水机为例,针对高有机分污泥含水率无法稳定达标的问题,制订改善污泥脱水性能的生产性试验计划。经1个月生产性试验,离心脱水污泥含水率稳定控制在80%以下,运行工况稳定,取得较好的效果。

反应沉淀一体式生物反应器在水质净化厂应急处理中的应用

为解决滨河水质净化厂提标扩建实施阶段服务片区内污水处理缺口,设计采用反应沉淀一体式生物反应器,将该工艺模块安装在水质净化厂的原有池体内,进行原位改造。在调试运行过程中,发现该工艺具有占地省、投资较低、改造时间较短等优点,同时在设计和运行中需着重考虑选用合适的气水比、停留时间和污泥负荷,以最大限度发挥该工艺的优势。

基于组合流量法的城市供水系统小区漏损诊断和预警

近年来,城市供水管网漏损问题频发,小区供水管网作为供水管网的最后一公里,降低小区管网漏损已成为供水企业的重要工作内容。文章针对夜间最小流量移动平均隔差法诊断不及时等问题,提出了一种基于全天流量的判别阈值矩阵分析的漏损诊断预警方法,利用全天流量趋势构建判别阈值矩阵诊断漏损,还将基于全天流量的判别阈值矩阵分析法与夜间最小流量移动平均隔差法结合,提出了一种基于全天流量和夜间最小流量的组合型漏损诊断预警法。将夜间最小流量移动平均隔差法、基于全天流量的判别阈值矩阵分析法和组合流量法分别应用于S市的30个DMA小区,识别准确率分别可以达到73.52%、78.19%和91.28%。结果表明,文章提出的基于全天流量的判别阈值矩阵分析法以及组合型漏损诊断预警法在解决小区供水管网漏损问题方面具有较好的应用前景和实际效果。

BIM在智慧水厂扩能改造工程施工阶段的应用

随着数字化水平的持续提升,数字建造已成为建筑业战略转型的关键路径。为了满足日益增长的居民对优质饮用水的需求,城市既有水厂的处理工艺需要进行全面升级和扩能改造。位于深圳市中心的某水厂扩能改造工程面临用地紧张、厂区管线保护、供水安全保障、水下湿法顶管作业以及复杂空间设备安装等多重施工挑战。通过应用倾斜摄影、GIS、Dynamo、Civil 3D、Revit、AR、BIM5D等技术,该项目实现了场地优化、多专业模型整合、模拟分析、可视化方案比选、三维技术交底及数字化项目管理,有效解决了上述问题。整体上,项目显著提高了施工效率和质量,实现了在不停产状态下的扩能改造,最终达到了提升质量和效率的目标。

协同除臭技术在罗芳污水处理厂中的工程应用

罗芳污水处理厂位于深圳边境,毗邻中国香港,紧邻居民区,“邻避效应”明显,项目采用生物原位除臭系统、末端除臭系统和新风系统对该污水处理厂进行除臭,其中末端除臭系统由封闭工程、臭气精准收集输送工程、协同臭气处理工程等构成。文章简要介绍了3大除臭系统的主要除臭原理,并阐述了该3大除臭系统在该污水处理厂的应用效果。臭气处理后切实提升了周边的环境质量,能够满足设计执行的排放标准,实际运行优于《城镇污水处理厂污染物排放标准》(GB 18918—2002)一级标准,成为破解“邻避效应”的典范。

沉积物异化铁还原耦合植酸去磷酸化

研究沉积物中微生物驱动的异化铁还原与有机磷降解转化的耦合作用,对深入阐明水体富营养化发生机制、控制环境磷污染和应对潜在的全球性磷危机具有重要的现实意义。该研究以沉积物异化铁还原与有机磷降解转化耦合的环境效应为切入点,探究了异化铁还原促进植酸有机磷去磷酸化的可行性。首先通过对武汉东湖自然沉积物中有机磷与亚铁含量的监测,以及两者之间的相关性分析,发现在以有机质降解为驱动力的早期成岩过程中,三价铁逐渐被还原为亚铁,同时伴随着有机磷含量的降低,揭示沉积物中铁的异化还原可能促进有机磷的降解转化;接着利用富集的沉积物内源微生物群落在实验室构建“异化铁还原微生物群落+水铁矿+植酸”微宇宙模拟系统,开展了铁还原微生物群落驱动异化铁还原对植酸有机磷降解转化作用的研究,进一步证实铁的异化还原能促进植酸有机磷的去磷酸化并生成PO_(4)^(3-),很可能是诱导水体富营养化的潜在新机制。

基于车载大型设备的水质移动监测车快速检测技术在突发性水质事件中的应用及展望

突发性水质事件具有不确定性、偶然性及危害性等特点,高效、便捷、快速是处置突发性水质事件的主要原则。有效的快速检测技术可迅速判断污染物的种类、浓度及危害程度,是提升突发性水质事件应急处置效率的关键环节之一。文章对基于车载大型设备的水质移动监测车快速检测技术进行介绍,移动监测车机动性强、反应迅速,通过搭载电感耦合等离子体质谱仪(ICP-MS)、气相色谱质谱联用仪(GC-MS)等大型检测设备,其具备多项痕量金属、有机物指标的快速检测与筛查能力,能在突发性水质事件中提供强有力技术支持。随着在检测能力、检测模式、标准及资质评审等方面的提升,未来基于车载大型设备的移动监测车将具有更多优势,在突发性水质事件应急处置中发挥愈发重要的作用。