原水氨氮含量对氯投加量的影响研究

通过对不同氨氮含量的原水加氯后产生折点曲线的研究,确定合适的加氯消毒方式,同时针对常规处理工艺找出原水中氨氮值上限,从而为水厂加氯工艺提供参考。     

叠式曝气生物滤池预处理高氨氮原水

针对南方地区存在季节性高氨氮和有机物污染的水源水,采用叠式曝气生物滤池进行生物预处理.枯水期水温≥5℃,滤速为8 m/h,气水比为0.5～1.5,原水氨氮、CODMn和浊度的周均值分别为5.02～9.45 mg/L、5.79～10.1 mg/L和19.7～63.1 NTU,叠式滤池出水对应指标分别为0.30～0.96 mg/L、3.24～5.85 mg/L和3.83～19.9 NTU(去除率分别为90.3%、42.7%和66.3%),符合<地表水环境质量标准>(GB 3838-2002)的Ⅲ类标准.丰水期滤速为12 m/h,气水比为0.3～0.5,原水氨氮、CODMn和浊度的周均值分别为2.19～3.41 mg/L、5.30～7.56 mg/L和27.3～40.1 NTU,叠式滤池出水对应指标分别为0.18～0.41mg/L、2.87～4.50mg/L和5.43～16.8 NTU(去除率平均为89.3%、40.2%和65.0%),符合GB 3838-2002的Ⅱ类标准.初滤池去除了原水中大部分可滤SS,为曝气生物滤池的稳定运行创造了条件,同时使曝气生物滤池过滤水头损失的24 h变化量不超过2 kPa,满足了多座滤池共用鼓风曝气系统,实现均匀曝气对过滤水头损失的控制要求.叠式曝气生物滤池的工艺投资约为140～180元/m3,运行费用约为0.05～0.07元/m3.     

生物活性炭滤池处理高氨氮原水

研究了深度处理工艺中生物活性炭滤池处理高氨氮原水的运行特性。试验结果表明,在水温>6℃时,生物活性炭滤池对氨氮的硝化能力受水中DO限制,原水中的高浓度氨氮对去除COD有较大影响。在水温较低时(2℃左右)生物活性炭滤池对氨氮的硝化能力下降50%。     

处理高氨氮、高有机物原水的混凝剂选择试验

该文介绍了以高氨氮、高有机物污染的淀浦河原水为对象,通过混凝沉淀烧杯试验进行混凝剂使用效果的对比性研究。阐述了硫酸铝（AS）和聚合氯化铝（PAC）对浊度、色度、UV254、耗氧量的去除效果,并作出比较。     

高藻类洋河原水处理方法探讨

针对高藻类洋河原水采取了多级预处理（预加硫酸铜、预加氯、高锰酸钾预氧化）,高分子助凝剂HCA配合三氯化铁、投生石灰调整pH值等一系列处理方法,并对药剂的投加方式、投加量、投加点作了简单介绍。实际生产运行中对藻类的去除率达97%。     

活性无烟煤滤池处理高氨氮原水的中试研究

针对南方饮用水源水氨氮和有机物浓度季节性上升的特点,开展了活性无烟煤多功能滤池处理高氨氮原水的中试研究。中试处理规模为120 m3/d,滤速为8 m/h,原水氨氮平均浓度为3.1 mg/L。试验结果表明,滤池进水溶解氧浓度不足会导致工艺出水氨氮浓度高于《生活饮用水卫生标准》(GB 5749—2006),同时伴随有亚硝态氮的积累;当采用纯氧曝气提高滤池进水DO至11.9～13.6 mg/L后,活性无烟煤滤池的净水效果大幅提高,出水氨氮<0.1 mg/L,亚硝态氮浓度几乎为零,氨氮全部转化为硝态氮,氨氮有效去除浓度与所需DO浓度的比值平均为1∶4.49。在纯氧曝气条件下,滤池对氨氮的去除率达到97%,对CODMn和UV254的去除率均在44%左右。     

原水氨氮较高期间氯耗高的原因及对策

汕头市月浦水厂近年来在3月-5月间常出现持续10多天的原水氨氮浓度较高的现象,此间氯耗显著增高.针对这一问题,从水体及制水构筑物的耗氯情况、加氯方式以及余氯测定方法造成的影响三个方面进行了分析,建议原水氨氮浓度较高期间采取定期向各构筑物内投加适量次氯酸钙（漂粉精）,对出厂水余氯以总氯控制代替游离氯控制,统一使用DPD法测定余氯等措施加以解决.     

消毒过程中氨氮对氯耗的影响研究

某水厂将地下水与管网水混合作为原水,直接加氯后进入清水池,运行中发现清水池出水中的余氯值变化不规律,有时会出现加氯量越多,出水余氯反而越少的现象.通过静态加氯试验验证了氯耗波动的事实,并与氨氮配水试验作对照,发现原水水样与氨氮配水的加氯曲线存在相似性；通过对折点加氯曲线的分析以及与原水加氯曲线的比较,认为原水加氯符合折点加氯特性,氨氮和管网来水中余氯的变化是造成氯耗不稳的原因.     

微污染水源水中氨氮去除研究

本研究通过模拟实际水厂运行的状况,比较了折点加氯法和投加沸石粉去除水源水中的氨氮的效果。研究发现,投加2g/L沸石粉能将氨氮浓度从2.35mg/L降低至1.08mg/L,但继续投加沸石粉无法进一步去除氨氮;相比较而言,折点加氯法是水厂用来去除氨氮比较合适的方案,效果上更具有优势和经济性,它能够将氨氮浓度降低至0.5mg/L,并且亚硝酸盐的去除几乎达到100%,当pH值为7.6时,折点加氯法能够取得最好的氨氮去除效果。     

高氨氮污水的治理措施探讨

笔者结合多年工作经验选用以（ABFT）生物曝气流化池为核心技术、以化学物理为辅助方法的工业化技术,对高氨氮污水进行有效处理。经过处理显示结果：在废水外排项目监测中其BOD、挥发酚、氰化物、悬浮物、硫化物、氨氮、pH值、石油类、COD的平均浓度含量均低于综合排放污水标准,即（GB7889-1996）规范规定的一级标准,在规范中：氨氮含量为O．52mg／L,COD含量为82．78mg／L。对氨氮、硫化物、悬浮物、COD、挥发酚等的消除率高达95％以上,BOD与石油类的消除率也能达到70％以上,因而获得理想的效果。     

再生水中氨氮和总氮的相关性分析研究

通过检测某再生水厂生活出水中的氨氮和总氮含量,分析了氨氮和总氮含量之间的相关性.结果表明,再生水中氨氮和总氮两个监测因子之间的相关关系为：秋季最好,R为0.992 5;冬季其次,R为0.934 6;最后是春季和夏季,R分别为0.777 0和0.725 7.氨氮和总氮含量之间的比例系数为0.010～0.310,波动较大,根据各不同季节氨氮和总氮的比例系数K季均值,可以得到氨氮和总氮含量的比例系数K年均值为0.078.     

沸石处理高氨氮景观水吸附特性实验研究

以景观水体为实验对象,阐述了沸石去除氨氮的吸附特性,实验结果表明:使用沸石处理高氨氮景观水,氨氮去除率超过90%;等温吸附试验研究结果显示所选用的沸石去除氨氮符合经典等温吸附模型朗格缪尔(Langmuir)等温模型,吸附极限值为4.642 3 mg/g;在25℃时,沸石对氨氮的去除率为93.4%。     

Photometric determination of ammonium nitrogen with the nessler reagent in drinking water after its chlorination

The photometric procedure for determining ammonium nitrogen in the drinking water containing inorganic chloramines has been refined. The preliminary reduction of chloramines at pH 4–9 was performed by using sodium sulfite at the fixed concentration in the interval 0.1–0.2 mM. Thereafter the mixture of solutions K₂HgI₄ (1–2 mM) and NaOH (80–100 mM) was added and the optical density of the resultant colored solution was measured at 440 and 600 nm.     

渔业水体中非离子氨的危害及检测方法的研究

非离子氨是反映渔业水体污染的重要指标之一。本文阐述了非离子氨对渔业水体的危害以及渔业水体中非离子氨与氨氮的转化关系,并对检测氨氮的方法进行了对比和分析。结果表明,流动注射-水杨酸光度法可以准确、快速测定渔业水体中氨氮值及非离子氨值。     

H2O2催化氧化预处理受污染源水的试验研究

利用静态批量试验研究H2O2在FeSO4,FeCl3和水合MnO2三种催化剂的作用下对受污染源水预处理的效果,试验结果表明H2O2催化氧化预处理对受污染源水中的浊度、UV254和TOC的去除有较好的效果。     

基于LS-SVM的养殖水体氨氮含量分析模型的优化

水体氨氮浓度是水产养殖的关键水质指标,为了提高氨氮浓度的测量精度,减少测量过程中p H、温度、静置时间等因素对准确度的影响,使用最小二乘支持向量机(LS-SVM)算法建立了分析预测模型,通过正交试验仿真测试,获取各因素的最佳优化组合为p H值10.5、反应温度35℃、静置时间20 min、检测光源波长380 nm。仿真结果表明,在设计在线式氨氮检测系统时,利用最佳优化组合对氨氮浓度分析模型进行优化,提高了氨氮浓度的测量精度。     

厨余垃圾生物炭的制备及其吸附水中氨氮的研究

以厨余垃圾为原材料,在不同温度、不同停留时间下将其制成生物炭,研究了生物炭对氨氮的吸附效果和影响因素.生物炭对氨氮的吸附不仅包括物理吸附,还存在复杂的化学吸附,使用Langmuir模型可以更好地拟合描述吸附等温线,其动力学过程可以采用伪二级动力学方程描述.     

Redox control in breakpoint chlorination of ammonia and metal ammine complexes

Redox control of breakpoint chlorination of ammonia and metal ammine complexes (Cu²⁺, Ni²⁺, Cr³⁺, Zn²⁺, Cd²⁺) is investigated. In simulated waste streams it is shown that at pH 8 control is feasible with a large (400 mV) and reproducible increase in the potential of a gold or platinum indicator electrode occurring at the breakpoint. At pH 10 control is less practicable due to the slowness of response, irreproducibility and smaller magnitude of the potential change. Simultaneous pH control is critical.     

Disinfection by-products formation and precursors transformation during chlorination and chloramination of highly-polluted source water: Significance of ammonia

Many studies have demonstrated the different trends of disinfection by-products (DBPs) formation between chlorination and chloramination. However, the reactions between precursors and disinfectants are widely assumed to be “black box” and the reasons for abovementioned difference are not well illustrated. This study focused on source water with high levels of natural organic matter (NOM) and bromide, and compared the transformation of NOM specific characteristics and the ratios of specific DBPs as an equivalent of chlorine to total organic halogen (TOX) among three disinfection scenarios of chlorination, chloramination and chlorine–chloramine sequential treatment (Cl₂–NH₂Cl process). A three-reaction-phrases model was proposed thereafter to illustrate the major reactions involved in, i.e., stage-I: rapid consumption of fast reactive sites (DOC₁), which transformed to slow reactive sites (DOC₂) and measured DBPs, i.e., trihalomethanes, haloacetic acids, etc; stage-II: oxidation and/or halogenation of DOC₂ into unknown TOX (UTOX) intermediates; stage-III: oxidation of UTOX intermediates into measured DBPs. The effect of ammonia was also quantified. Ammonia is observed to inhibit the formation of measured DBPs by 68–92%, 94–99%, and 92–95% of that in chlorination in Stage-I, II, and III, respectively, and the formation of UTOX is reduced by 2–80%, 60–94%, and 82–93% accordingly. These effects lead to the steady accumulation of DBPs intermediates such as UTOX, and to the elevated UTOX/TOX during chloramination and Cl₂–NH₂Cl process thereafter. The results illustrate the mechanism of ammonia participating in DBPs formation, and are valuable to fill in the gap between the transformation of precursors and the formation of different DBPs.     

Measurements of dissolved organic nitrogen (DON) in water samples with nanofiltration pretreatment

Dissolved organic nitrogen (DON) measurements for water samples with a high dissolved inorganic nitrogen (DIN, including nitrite, nitrate and ammonia) to total dissolved nitrogen (TDN) ratio using traditional methods are inaccurate due to the cumulative analytical errors of independently measured nitrogen species (TDN and DIN). In this study, we present a nanofiltration (NF) pretreatment to increase the accuracy and precision of DON measurements by selectively concentrating DON while passing through DIN species in water samples to reduce the DIN/TDN ratio. Three commercial NF membranes (NF90, NF270 and HL) were tested. The rejection efficiency of finished water from the Yangshupu drinking water treatment plant (YDWTP) is 12%, 31%, 8% of nitrate, 26%, 28%, 23% of ammonia, 77%, 78%, 82% of DOC (dissolved organic carbon), and 83%, 87% 88% of UV₂₅₄ for HL, NF90 and NF270, respectively. NF270 showed the best performance due to its high DIN permeability and DON retention (∼80%). NF270 can lower the DIN/TDN ratio from around 1 to less than 0.6 mg N/mg N, and satisfactory DOC recoveries as well as DON measurements in synthetic water samples were obtained using optimized operating parameters. Compared to the available dialysis pretreatment method, the NF pretreatment method shows a similar improved performance for DON measurement for aqueous samples and can save at least 20 h of operating time and a large volume of deionized water, which is beneficial for laboratories involved in DON analysis. DON concentration in the effluent of different treatment processes at the YDWTP and the SDWTP (Shijiuyang DWTP) in China were investigated with and without NF pretreatment; the results showed that DON with NF pretreatment and DOC both gradually decreased after each water treatment process at both treatment plants. The advanced water treatment line, including biological pretreatment, clarification, sand filtration, ozone-BAC processes at the SDWTP showed greater efficiency of DON removal from 0.37 to 0.11 mg N L⁻¹ than that at the YDWTP, including pre-ozonation, clarification and sand filtration processes from 0.18 to 0.11 mg N L⁻¹.