高铁酸盐复合药剂氧化助凝效能研究

对高铁酸盐预氧化在常规水处理工艺基础上的净水效能通过与高锰酸钾的对比试验进行了研究.试验结果表明,对于微污染水源,高铁酸盐预氧化可有效地去除部分有机物,并具有良好的助凝除浊作用.高铁酸盐的助凝除浊除微污染作用优于高锰酸钾,是一种性能更加优良的助凝剂.     

强化混凝-沉淀-砂滤工艺去除海水中藻类的试验研究

通过考察强化混凝中混凝剂种类及投加量、氧化性助凝剂种类及投加量、氧化时间、pH以及水力条件等因素对海水中Chl-a、CODMn去除效果的影响,确定了试验参数,并后续加入砂滤工艺考察其除藻效果.结果表明:在调节海水pH值为5～6,选用3 mg/L高锰酸钾预氧化30min后,投加混凝剂聚合氯化铝铁(PAFC)对Chl-a和CODMn均有较佳的去除效果.强化混凝-沉淀-砂滤工艺对Chl-a平均去除率可以达到80%以上,对CODMn去除率在50%左右,对浊度的去除率大干97%.     

高铁酸钾处理景观水体的效果研究

研究了高铁酸钾对景观水体中浊度、COD、溶解性COD、TN、TP和藻类的去除效果,并与聚合氯化铝(PAC)、硫酸铝和氯化铁的去除效果进行了对比,同时还考察了上述几种药剂的污泥产生情况以及高铁酸钾对水体可生化性的影响。结果表明,与其他几种混凝剂相比,高铁酸钾对浊度、COD、溶解性COD、TP和藻类的去除效果更好,但对TN的去除效果比PAC略差;高铁酸钾去除的污染物量较多,产生的污泥量较少;高铁酸钾可提高景观水体的BOD5/COD值,显著改善了水体的可生化性。     

太湖流域含藻原水的处理技术及运行效果研究

针对太湖流域地区的夏季含藻水源水采用了投加高锰酸钾预氧化、高锰酸盐复合药剂(PPC)氧化助凝、聚丙烯酰胺(PAM)助凝、加碱调整pH值、聚硫氯化铝(PACS)混凝和助凝等几种处理方法,并对药剂投加条件等进行了研究.生产试验结果表明,投加高锰酸钾预氧化对藻类和CODMn的最高去除率分别为84.3%和24.1%.烧杯搅拌试验结果表明,PAM强化助凝、加碱调整pH值和PPC氧化助凝三种处理技术对含藻水的处理效果较佳,其作为应急工艺运用到生产上的可操作性较强.     

Effectiveness of ferrate (VI) preoxidation in enhancing the coagulation of surface waters

Standard jar tests were conducted to evaluate the effectiveness of ferrate preoxidation in enhancing the coagulation of surface waters. A substantial reduction of residual turbidity after sedimentation and filtration was achieved by ferrate preoxidation in all cases of the investigation of various water qualities at low ferrate dosage (0.5–1.0 mg/l). The enhancement of the coagulation was more obvious when the organic content in the waters were relatively high.     

饮用水常规处理工艺的优化中试研究

通过投加高锰酸钾复合药剂预氧化、投加HCA助凝剂和气浮、沉淀对比试验,进行了常规工艺的优化研究。结果表明,预氧化对浊度和CODMn去除率都有一定的提高,且在混凝剂投加量相同的情况下,高锰酸钾复合药剂投加量为0.8 mg/L时,浊度的去除效果最好。投加助凝剂后,出水浊度降低,CODMn去除率提高,但水头损失增加较快,过滤周期缩短。     

不同水处理工艺流程对除藻效果的影响

为了解和考察不同处理流程、各种预氧化剂的除藻效果及对除藻特性的影响，首先研究了春季天津市“引黄”原水藻类的数量与分布特征，发现该季节优势藻为小球藻、绿梭藻和栅列藻。对比了预氯化沉淀、单独气浮、预臭氧化气浮和高锰酸盐复合药剂(PPC)预氧化气浮工艺的除藻效果和除藻特性。结果表明各种工艺流程的除藻特性有明显差异，采用气浮工艺代替沉淀工艺能够提高对原水中不同优势藻的去除率，预臭氧化和PPC预氧化能够进一步提高气浮工艺对优势藻的去除率。PPC预氧化去除小球藻更有效，而预臭氧化去除绿梭藻和栅列藻效果更好。预臭氧化和PPC预氧化能够提高气浮工艺去除叶绿素a的能力。     

预投加高铁酸盐强化混凝去除原水中的铅、镉

采用烧杯试验考察了预投加高铁酸盐强化混凝去除原水中铅、镉的效果。结果表明，高铁酸盐投量为5mg／L时混凝沉淀对铅、镉的去除率分别约为93％和80％；投加高铁酸盐的预处理对铅、镉的去除效果优于三价铁盐的；对铅、镉的去除率随pH值的升高而提高，高铁酸盐在较宽的pH值范围内对铅、镉均有较好的去除效果；对镉的去除较铅困难，适当提高pH值可强化高铁酸盐对镉的去除效果。     

臭氧预氧化技术对水厂常规工艺的影响

通过生产性试验考察了臭氧预氧化技术对水厂常规工艺的影响.结果表明,臭氧预氧化技术具有明显的助凝效果,在实际生产中可降低常规工艺的出水浊度,同时可减少矾耗约28％左右;臭氧预氧化技术能提高常规工艺对耗氧量和氨氮的去除率,使二者的去除率分别提高15％和50％左右;若仅从成本方面考虑,采用臭氧预氧化技术降低矾耗是不经济的,但是在特殊原水水质情况下,将臭氧预氧化技术和混凝沉淀常规工艺相结合会明显改善出水水质,减少高矾耗带来的出厂水pH值低及铝离子超标等不利影响.     

臭氧预氧化技术在给水处理中的研究进展

介绍了臭氧预氧化技术在饮用水处理中的应用,包括臭氧预氧化助凝,臭氧预氧化改善浊度、色度、嗅味等感官指标,臭氧预氧化去除无机、有机污染物,臭氧预氧化对致病微生物、藻类、消毒副产物等的处理效果,以及臭氧预氧化在强化常规处理工艺过程中起到的作用。表明臭氧具有多方面的除污染效能,对给水处理工艺的发展和饮用水水质的提升有显著促进作用。同时也提出了存在的一些问题,便于今后的研究和应用中进一步改进和完善。     

Enhanced coagulation for high alkalinity and micro-polluted water: the third way through coagulant optimization

Conventional coagulation is not an effective treatment option to remove natural organic matter (NOM) in water with high alkalinity/pH. For this type of water, enhanced coagulation is currently proposed as one of the available treatment options and is implemented by acidifying the raw water and applying increased doses of hydrolyzing coagulants. Both of these methods have some disadvantages such as increasing the corrosive tendency of water and increasing cost of treatment. In this paper, an improved version of enhanced coagulation through coagulant optimization to treat this kind of water is demonstrated. A novel coagulant, a composite polyaluminum chloride (HPAC), was developed with both the advantages of polyaluminum chloride (PACl) and the additive coagulant aids: PACl contains significant amounts of highly charged and stable polynuclear aluminum hydrolysis products, which is less affected by the pH of the raw water than traditional coagulants (alum and ferric salts); the additives can enhance both the charge neutralization and bridging abilities of PACl. HPAC exhibited 30% more efficiency than alum and ferric salts in dissolved organic carbon (DOC) removal and was very effective in turbidity removal. This result was confirmed by pilot-scale testing, where particles and organic matter were removed synergistically with HPAC as coagulant by sequential water treatment steps including pre-ozonation, coagulation, flotation and sand filtration.     

受典型除草剂污染原水的应急处理工艺研究

以水中阿特拉津和莠灭净浓度突增为背景,研究了混凝、PAC吸附和PAC吸附＋混凝等工艺对它们的去除效率,同时根据原水水质的变化和水厂的常用工艺,分别考察了混凝剂投加量、pH值、预氧化对混凝去除阿特拉津和莠灭净的影响,以及目标物初始浓度、天然有机物浓度和预氧化对PAC吸附的影响。结果表明,调节pH值及采取预氧化措施均能改善混凝对阿特拉津和莠灭净的去除效果,但其出水浓度仍不能达标;天然有机物浓度对PAC吸附的影响并非是简单的线性关系,同时投加氧化剂和PAC会相互削弱其作用,PAC吸附＋混凝才是去除阿特拉津和莠灭净最简单、有效的方法。     

Colour and turbidity removal with reusable magnetic particles—II. coagulation with magnetic polymer composites

Composite particles containing magnetic iron oxides in an insoluble polymeric matrix were used to enhance the coagulation of a turbid, coloured river water. Uncharged magnetic particles increased the turbidity removal at a given alum dose, or alternatively achieved a desired level of turbidity removal at a lower alum dose. Rates of floc formation and settling were approximately double those obtained with alum alone. Grafting linear polymers to the magnetic particles increased their effectiveness. The uncharged particles could be reused after simply washing with water. Magnetic particles with grafted chains of cationic polymers, when used in conjunction with alum, gave excellent removal of colour and turbidity and rapid settling, but required brine for regeneration. These materials were also effective in coagulating algae. When used in high doses without alum, the cationic magnetic particles initially gave good turbidity and colour removal from river water, but could not be completely regenerated     

PPC预氧化处理珠江水系受污染水的效能研究

以珠江后航道和西江受污染水为研究对象,分别用烧杯试验和生产性试验考察了高锰酸盐复合药剂(PPC)预氧化的强化除污效能.烧杯试验结果表明,PPC预氧化对于珠江后航道受污染水具有明显的助凝、助滤和去除有机物的作用,使沉后和滤后水浊度、CODMn和对UV254的去除率比单独投加混凝剂时有显著改善;生产性试验结果表明,PPC对于西江受污染水具有较好的强化除浊和除有机物效能,并且能延长滤池的过滤周期.由于水厂自身生产状况和原水水质的不同,PPC对两种水源水的除浊和除有机物效能存在差别.GC/MS的分析结果表明,PPC对源水中的微量有机污染物具有良好的去除效果,可提高饮用水的化学安全性.PPC预氧化工艺是一种可以提高此类水体出水水质,保障饮用水安全的有效处理技术.     

Effects of raw water conditions on solution-state aluminum speciation during coagulant dilution

The speciation of aluminum in solutions of alum and various prehydrolyzed, aluminum-based water treatment coagulants was investigated by 27Al NMR at 5 degrees C and 25 degrees C. Alum solutions were seen to contain only mononuclear species including an AlSO4(+) complex, while the prehydrolyzed coagulant solutions contained polynuclear aluminum species, as well. The relative proportions of both polynuclear species and AlSO4(+) complex decreased in cold water. The presence of organic matter had little effect on the speciation of aluminum in diluted alum, but markedly reduced the relative proportion of the tridecamer species in the prehydrolyzed coagulant solutions. The relationship between Al speciation in the coagulants and organic matter removal during jar tests was considered, and the possible role of sulfate in both the formation of the tridecamer species and the effect of organic matter on coagulation efficiency was discussed.     

混凝/气浮与混凝/沉淀工艺处理微污染原水的对比

采用混凝/气浮工艺代替混凝/沉淀工艺,进行了处理北方地区微污染原水的中试研究。中试装置由不锈钢制成,处理水量为120 m^3/d,通过连续运行对比了两系统对浊度、UV254、CODMn、TOC、藻类、THMFP等指标的去除效果。试验结果表明,与传统的混凝/沉淀工艺相比,混凝/气浮工艺具有运行稳定、除污效果好、药耗低等优点,适合处理北方地区的微污染原水。     

水厂除藻除嗅试验研究

针对高藻期水库水采用高锰酸盐复合药荆(PPC)、高锰酸钾(KMnO4)和氯进行了化学预氧化强化水厂除藻除嗅性能的试验研究,并与单独使用混凝剂时的处理效果进行了对比.结果表明,PPC对水库高藻水具有较好的除浊和除有机物效果,且高于KMnO4;PPC预氧化对藻类和臭味的去除效果高于KMnO4预氧化.     

Chitosan and metal salt coagulant impacts on Cryptosporidium and microsphere removal by filtration

Maintenance of appropriate chemical pretreatment is a critical component of ensuring proper filtration performance. Pilot-scale in-line filtration studies were performed to investigate the relative impacts of chitosan, alum, and FeCl₃ coagulation on the removal of Cryptosporidium parvum oocysts and oocyst-sized polystyrene microspheres by granular media filtration. Similar removals of oocysts and microspheres were achieved when optimal coagulant doses were utilized. Sub-optimal alum and FeCl₃ coagulation resulted in a deterioration filter effluent turbidity (0.2-0.3 NTU) and total particle counts (30-100 total particles ≥2 μm/mL) that were accompanied by reduced (by ∼2-3-log) median oocyst and microsphere removals by filtration. At all doses investigated, chitosan coagulation resulted in excellent turbidity and particle reductions by filtration. Nonetheless, chitosan coagulation at doses of 0.1, 0.5, and 1.0 mg/L did not result in appreciable improvements in C. parvum oocyst removal relative to complete coagulation failure (median oocyst removals were <∼1-log). As well, oocyst-sized polystyrene microspheres appear to be reasonable indicators of C. parvum oocyst removal by in-line filtration preceded by alum and FeCl₃ coagulation, but not chitosan coagulation.     

生物预处理富营养化水源水的试验研究

采用生物陶粒滤柱作为预处理工艺,考察了其对滏阳河水的处理效果以及影响因素,并确定了运行参数。试验结果表明:生物滤柱对各种藻的去除效果不同,且去除率随滤速的上升而降低;有机物的去除率受滤速影响不大,但随着温度的上升而提高。生物预处理不但能够降低混凝剂的用量,而且使溶解氧增大,改善了水质。     

Effects of pre-ozonation on the removal of THM precursors by coagulation

Pre-ozonation in combination with enhanced coagulation was used to remove NOM from lake water as to control the formation of disinfection by-products, DBPs. The effect of the hydrophobicity/hydrophilicity nature of NOM on the performance of the combined pre-ozonation and coagulation process was studied. The hydrophilicity/hydrophobicity property of NOM was characterized in terms of mass distribution of the phydrophilic and the hydrophobilic fractions of NOM. The optimal condition for the combined pre-ozonation-coagulation was established: pH = ca. 9.0 and ozone dose = 0.45 mg-O₃/mg-DOC. Under the optimal condition, it was able to achieve ∼ 60% of THMFP removal. In terms of THMPF, results also indicated that the distribution between the hydrophilic and the hydrophobic fractions of NOM was 57.3 and 98.7 µg-THMFP/mg-DOC, respectively. Ozonation alters the structures and characteristics of NOM thereby affecting the coagulation effectiveness. Pre-ozonation was effective in removing the hydrophobic NOM, with a decrease of THMFP by ∼ 20% versus ∼ 10% for the hydrophilic fraction. The dosage of coagulant also governed DOC removal. The removal of hydrophobic and hydrophilic NOM were in the range of 27-41 and 2.5-22.7%, respectively at alum dosage of 0.41-1.65 (in Al/DOC) and 0.41-1.65 (in Al/DOC) and ozone dose of 0.58-2.93, mg/mg respectively. The adsorption characteristics of the hydrophilic and the hydrophobic fractions of NOM on aluminum hydroxide (from coagulant alum) were studied. Results indicated that the modified Langmuir isotherm of competitive adsorption was able to describe the adsorption of NOM onto hydrous aluminum hydroxide formed during alum coagulation of the lake waters.