助凝剂活化硅酸与HCA处理水库水的效果研究

珠海市A水厂水源为水库水,水质特点为低浊、高藻。水厂采用单一混凝剂处理效果差,面临混凝剂投加量大、生产运行管理难度大,出厂水水质下降等问题。本文以不增加新的工艺构筑物、不改变现有净水处理工艺为前提,通过搅拌试验和生产性试验,对比研究了含二甲基二烯丙基氯化铵(DMDAAC)的聚合产品HCA与活化硅酸分别作为助凝剂强化混凝的处理效果。结果表明:(1)单一混凝剂分别联合HCA和活化硅酸的强化混凝均优于单独投加混凝剂的效果;(2)HCA的助凝效果优于活化硅酸,但活化硅酸有改善絮凝体比重,使絮凝体更易下沉,可减少搅拌池的冲洗次数,降低水损;投加"PAFC+HCA"时搅拌池冲洗间隔时间为1～3.5天,投加"PAFC+活化硅酸"时搅拌池冲洗间隔时间为3～5天;(3)原水p H对HCA的助凝效果有一定的影响,当原水pH范围为6.8～8.0时药剂投加量相对较少,处理效果较好;当原水pH大于8时增大药剂投加量,处理效果仍不理想。(4)HCA配置简单,操作简便,安全性优于活化硅酸。     

改性活化硅酸净化低温、低浊水

比较了投加聚铝PAC＋改性活化硅酸（改性水玻璃）与单独投加PAC、投加PAC＋活化硅酸净化低温、低浊水的效果。生产应用表明，改性活化硅酸的使用可提高30％的产水量，降低50％的混凝剂投加量，降低净化成本约15％。     

用硫酸铝作活化剂制备活化硅酸的实验初探

结合水厂实际,采用工业硅酸钠为原料、硫酸铝作为活化剂,配制活化硅酸溶液,研究了配制活化硅酸的控制方法、最佳活化状态和保质期等.实验结果表明,当硅酸溶液配制浓度为0.7％(以SiO2计),活化剂(以Al2O3计)与SiO2的质量比为0.11:1～0.12:1时,控制剩余碱度在600～900 mg/L,所制得的活化硅酸助凝...     

壳聚糖-活化硅酸处理低温低浊水的试验研究

对壳聚糖-活化硅酸处理低温低浊度水进行了初步的探讨,考察了壳聚糖-活化硅酸的用量、pH、壳聚糖分子量等因素对处理效果的影响,找到了最佳的工艺条件.试验结果表明,在原水浊度为8～10 NTU,水温为5～10℃的条件下,当活化硅酸投加量为2 mL/L,壳聚糖投加量为1.2 mg/L时,出水浊度可达到0.54 NTU.     

活化硅酸处理低温低浊长江水的应用研究

以武汉长江水系的低温低浊水为研究对象,根据武汉地区水厂在低温低浊时的运行状况,并依据水质达标和降低水厂运营成本的原则,在众多改善水质的低温低浊处理技术中,采用最经济、最有效的技术方法---无毒高效的活化硅酸助凝剂进行了实验室试验到生产性应用试验研究。通过应用正交试验方法和烧杯搅拌实验,研究优选了活化硅酸助凝剂和PAC混凝剂的最佳投药量配比,及其投加的先后次序和间隔时间。     

降低饮用水中残余铝的中试研究

研究了水处理过程中铝含量的影响因素和控制条件,结果表明:对水中铝含量的影响PAC投加量＞pH＞滤速＞活化硅酸投加量.控制余铝的最佳条件是:PAC投加量2.0 mg/L,pH值7.5,活化硅酸投加量1.5 mg/L,滤速8.0 m/h.过滤阶段对铝的影响小于混凝阶段,水厂实际运行时应尽量采用低滤速.为控制出厂水铝含量,建...     

呼延水厂低温低浊水的絮凝试验研究

针对太原市呼延水厂出水浊度不达标的问题进行了絮凝试验研究.结果表明:该厂原水属低温低浊水,有机胶体较多,絮凝效果差,其根本原因是絮凝剂投量不足.进一步的试验表明:以聚合氯化铝(PAC)为絮凝剂、以活化硅酸为助凝剂,除浊效果较好;活化硅酸的投加时间对絮凝效果有较大的影响,以快速混合用时1min、聚合氯化铝投量为15 mg/L、延迟30 s后投加0.5～1mg/L的活化硅酸(以SiO2,计)为最佳运行条件;滤池反冲洗排水回流至配水井有利于低温低浊水的处理,并可节省絮凝剂或助凝剂的投量.     

强化混凝对三氯乙醛前体物的去除效能评价

以我国南方某微污染水源水为研究对象,研究聚合氯化铝(PACl)混凝及聚丙烯酰胺(PAM)、壳聚糖、活化硅酸助凝对水合三氯乙醛(CH)前体物的去除效果。结果表明,当PACl投加量为6 mg/L时对水合三氯乙醛生成势(CHFP)的去除效果最佳,去除率为52.94%,且对浊度、COD_(Mn)、DOC、UV_(254)也都有较好的去除效果;当PAM投量为0.12 mg/L时,对CHFP的去除效果最好,最大去除率提高了19.55%;当壳聚糖投加量为0.16 mg/L时,对CHFP的去除率最大,提高了14.96%;而活化硅酸助凝不适于对CH前体物的去除。     

活化硅酸配制和使用技术研究

研究了活化硅酸的配制特性,确定了最佳配制方法和在不同温度下的使用比例。结果表明,活化硅酸配制浓度宜控制在1.5%,碱度应控制在1800~2200 mg/L(以CaCO_3计),活化时间控制在50 min以上。采用二次活化的混凝效果好于一次活化,且能够节约三氯化铁使用量,但混合液比例应根据水温进行调整。     

空气搅拌在溶药系统中的应用

空气搅拌在溶药系统中的应用１前言沈阳市八水厂净水处理，混凝剂采用聚合氯化铝（ＰＡＣ），采用法国往复式计量泵投加，虽然可以根据原水流量自动调整投药量，但无法随处理效果或药剂浓度的变化而改变投药量。由于机械加药搅拌存在问题，药液浓度无法保证均匀有效投加，...     

水泥加固酸污染土无侧限强度特征

污染土是利用水泥固化处理后,土体的强度得到提高。针对该项技术,采用水泥固化法处理酸污染土,通过两种试验方案,对水泥加固酸污染土的无侧限抗压强度特性进行研究。试验所用酸污染土用浓硫酸配置人工制备而成,并考虑了不同水泥掺量、不同硫酸浓度和不同龄期对水泥加固酸污染土强度的影响。试验表明:水泥固化酸污染土的强度与水泥掺量和硫酸含量有密切关系,二者共同作用决定其强度的变化。在一定硫酸浓度(2~16g/kg)条件下,伴随硫酸含量的升高,水泥掺量较低时,无侧限抗压强度整体呈明显下降的趋势;水泥掺量较高时,无侧限抗压强度呈缓慢上升的趋势。随着水泥掺量提高,土样的无侧限抗压强度达到峰值时所对应的硫酸含量也逐渐变大。     

中和/微滤工艺处理重金属酸性废水的试验研究

采用中和／微滤工艺处理重金属离子酸性废水,考察了pH值、搅拌方式和搅拌时间及投加絮凝剂对各金属离子去除效果的影响。结果表明,反应的最佳pH值宜控制在9．0-9．5;机械搅拌的处理效果要优于鼓风搅拌的,搅拌时间控制在60min左右为宜;投加絮凝剂有助于对金属离子的去除,且加入絮凝剂后混合液中的颗粒粒径变大,分布较为集中。     

Coupling reverse osmosis with electrodialysis to isolate natural organic matter from fresh waters

Reverse osmosis (RO) has proven to be an effective method for the concentration of natural organic matter (NOM) from fresh waters, but an undesirable consequence of this process is the co-concentration of some inorganic solutes. Accordingly, current practice yields solutions of NOM that, upon desalting and freeze-drying, are converted into dry solids containing finely dispersed sulfuric acid and silicic acid (H(4)SiO(4)). These acids will contribute to the apparent carboxylic and phenolic contents of NOM, leading to an overestimation of both. NOM may also be chemically altered by sulfuric acid, which reacts strongly with many classes of organic compounds. The sulfur content and ash content of NOM will be elevated in the presence of sulfuric acid and H(4)SiO(4). The goal of this study is to develop and test a method in which the removal of water by RO is coupled with the removal of salts by electrodialysis (ED). Like RO, ED is a relatively mild treatment that enables the desalting of NOM solutions without subjecting those samples to conditions of extremely high or low pH. The end product of the coupled process is a desalted, concentrated liquid sample from which low-ash NOM can be obtained as a freeze-dried solid material. In this study, the efficacy of ED for desalting NOM is evaluated using concentrated synthetic river waters and actual concentrated (by RO) river waters. Under optimal operating conditions, both sulfate and silica can be largely removed from RO-concentrated solutions of riverine NOM with only an average loss of 3% of total organic carbon.     

烧渣制备聚合硫酸铁及其对造纸废水的处理效果

以硫铁矿烧渣、废硫酸和电石渣为原料,通过酸浸、调pH值、水解聚合制得聚合硫酸铁（PFS）絮凝剂。研究了废硫酸的浓度及用量、酸浸时间和水解pH值对制备PFS的影响,考察了所得PFS对造纸综合废水的处理效果。结果表明,PFS的最佳合成条件为：20g硫铁矿烧渣与35mL的45％废硫酸反应3h后,用20～30g的电石渣调节pH值至0．9～1．1。采用该PFS处理造纸综合废水,在用量为0．21g/L时絮凝速度快,矾花大且密实,脱色效果好,可使COD降至200mg／L以下．且处理成本仅为0．042元／m^3。     

Effect of acid and surfactant treatment on activated sludge dewatering and settling.

The effect of pretreating activated sludge with sulfuric acid and surfactant on its exocellular polymer(ECP), dewaterability and settleability was investigated. It was observed that the centrifugal dewatering efficiency was increased with the decrease of sludge pH value, and which was further improved if the surfactant was simultaneously applied. However, to the filtration dewatering, the water content reached the minimum in the case of pH 2.5, and the additional use of surfactant was also favorable. The water content of sludge dewatered with filtration reached 73.99% when a pH 2.5 and a 0.1 g surfactant were employed, which was reduced by around 2% as compared with surfactant unused. Experimental results indicated that the sludge sedimentation rate was significantly accelerated under pH 2.5 condition, and which was increased once more by the utilization of surfactant. Further studies revealed that treating activated sludge with sulfuric acid at pH 2.5 or combined with surfactant was an effective method to remove the polymers from sludge surface and induced the decrease of ECP, which resulted in the improvement of dewaterability and settleability. This study suggested the potentiality of improving activated sludge mechanical dewaterability by the use of sulfuric acid to control its pH at 2.5 or together with a surfactant.     

Regeneration of fibrous carboxylic ion exchangers FIBAN in water treatment processes

We investigated the processes of zinc regeneration of carboxylic ion exchangers FIBAN by the solutions of sulfuric acid and sodium sulfate. It is shown that the mode of direct-flow continuous elution of the ion exchanger by the regeneration solution is not promising enough. It is planned to carry out regeneration by the solution of sulfuric acid circulating through a sorbent layer. For preparation of the ion exchanger for a new cycle of sorption it is recommended to treat the material with a mixed solution of sodium hydroxide and sodium sulfate.     

天津西站地下出租车蓄车区通风系统模拟分析

本文以天津西站交通枢纽的地下出租车蓄车区为研究对象,建立了通风系统的数学模型,并用Airpak软件对其在不同换气次数工况下的污染物及温度分布进行了模拟分析。模拟结果表明:综合考虑空气品质、舒适性以及节能运行,得到最佳换气次数为10次/h;排风口位置对空气中污染物浓度没有显著影响,受热气流影响,将排风口设置在车辆集中区域上方的排风效果更好;由于污染源种类比较单一且空气流速较大,CO和CO2的浓度分布相似。本文结论对天津西站地下出租车蓄车区通风系统设计具有一定指导意义,也可为同类型建筑的通风系统设计提供参考。     

城市污泥中重金属消解方法的比较试验研究

采用四酸消解法、碱熔消解法、干灰化-王水消解法、浓硫酸-高锰酸钾消解法和硝酸加热煮沸消解法等5种方法处理城市污泥样品,以全谱直读-电感耦合等离子发射光谱仪测定其中的铜、锌、铅和汞金属的含量.试验结果表明,对于污泥中的铜和锌,碱熔消解法的消解效果较好;而对于污泥中的铅和汞,则宜采用四酸消解法和浓硫酸-高锰酸钾消解法.     

废浓硫酸池防腐方案优化与质量控制

宝钢不锈钢事业部冷轧废水处理站改造工程,是为了提高废水处理能力。因此,工程中新增废浓硫酸预沉池、储存池的防腐处理是本次改造的技术关键。如何在最短的工期内,完成池体的防腐施工,同时保证防腐层没有任何漏点,以防废浓硫酸腐蚀池体钢筋混凝土结构。经过技术方案比较优化,采用了美国进口涂料类防腐材料和先进防腐施工工艺。此项防腐技术在宝钢建设系统尚属首次,它的成功应用,不仅满足了工期要求,还保证了工程质量。     

State of the practice review of heap leach pad design issues

The authors present a summary of the state of the practice of containment design in copper and gold heap leaching, focusing on recent advancements and how these applications differ from the more conventional landfill design practices. Advancements both within the Americas and worldwide are presented, including consideration of increasing heap depths, which are now approaching 150 m (with ore densities generally in the range of 1500–1800 kg/m³). Liner system performance under these pressures will be reviewed, including the latest developments in drainage pipe performance testing. The authors will also explore the recently emerging technology of using concentrated sulfuric acid pre-curing for copper ores and the related compatibility issues with conventional geomembrane materials.