高浓度含砷盐酸废水处理的试验研究

采用ＫＭｎＯ４－石灰预处理,硫酸亚铁混凝沉淀法处理高浓度含砷盐酸废水,结果表明效果良好,出水砷残留量、ｐＨ值及色度均符合国家排放标准。     

氢氧化铁对水中砷的吸附试验研究

就氢氧化铁对As(Ⅲ)的吸附动力学、吸附等温线以及pH和温度等影响因素进行了研究。结果表明:氢氧化铁对As(Ⅲ)的吸附动力学符合Lagergren二级吸附动力学模型,其吸附等温线可用Langmuir方程很好地描述,即属于单分子层吸附,试验得到的饱和吸附量为9.09mg/g;pH值在4.1~8.5内,氢氧化铁对As(Ⅲ)的去除率较高,保持在70%以上,超出这个范围,氢氧化铁对As(Ⅲ)的去除率逐渐降低,pH值为6.8左右时,氢氧化铁对As(Ⅲ)的去除率达到最高,约为94.8%;随着温度的升高,氢氧化铁对As(Ⅲ)的吸附率逐渐降低,在0~25℃时,氢氧化铁对As(Ⅲ)的去除率保持在80%以上。     

生物除锰滤池对砷(Ⅲ)的去除效果研究

砷是对人体有毒害作用的典型元素,且在水源水中普遍存在.为此人工配制了含As（Ⅲ）为0.05～0.25 mg/L、Mn2＋为0.5～3.0 mg/L的原水,并通过已培养成熟的生物除锰滤池进行过滤,分别考察了滤速为3、5、7 m/h时滤池对As（Ⅲ）及Mn2＋的去除效果.结果表明,在开始阶段由于受原水中As（Ⅲ）的影响,滤池的除锰能力有所下降,出水As（Ⅲ）也不能达标;经过15 d左右的运行培养后,滤池表现出了良好的除锰和除砷能力,出水As（Ⅲ）、Mn2＋浓度分别为0.02mg/L和0.05 mg/L左右.经过对不同取样口的水样进行检测,发现滤池的除砷能力集中在厚度为0～800 mm的滤层.     

预氧化-混凝沉淀法快速去除水中砷研究

探讨预氧化-混凝沉淀法快速去除水中砷污染物的可行性,结果表明,在氧化时间均为10min条件下,KMnO4投加量为0．5mg／L时,聚氯化铝和聚合硫酸铁投加量分别为8mg／L和16mg／L时,可将原水中《生活饮用水卫生标准》（GB5749—2006）限值5倍浓度的砷降低到限值以下,去除率约90％。NaClO投加量（以有效氯计）为0．8mg／L时,聚氯化铝和投加量分别为8mg／L和20mg／L时,可将原水中《生活饮用水卫生标准》（GB5749—2006）限值5倍浓度的砷降低到限值以下,去除率约85％。以聚氯化铝为混凝剂的除砷效果优于聚合硫酸铁,以KMnO4氧化剂的除砷效果略优于NaClO。     

预氧化-化学沉淀法去除水中砷的试验研究

研究了预氧化-化学沉淀法对水中砷的去除效果及其影响因素。结果表明,原水砷质量浓度为5倍标准限值时,在NaClO预氧化条件下,投加8 mg/L的聚合氯化铝可使砷去除率达到84%,且出水砷含量可以满足《生活饮用水卫生标准》(GB 5749—2006)限值要求;在KMnO4预氧化条件下,投加8 mg/L的聚合氯化铝可使砷去除率达到90%,且出水砷含量满足标准限值要求,而投加8 mg/L的聚合硫酸铁可使出水砷含量降至18.72μg/L,无法满足标准限值要求;采用聚合氯化铝作为混凝剂时的除砷效果优于聚合硫酸铁,以KMnO4作为预氧化剂时的除砷效果优于NaClO。     

铁砷复合污染下铁砷比对除砷效果的影响研究

针对铁砷复合污染型地下水,以原水铁砷比作为控制参数,通过烧杯试验研究了曝气接触氧化除铁工艺的除砷效果。结果表明,当初始砷含量分别为100,200,300和400μg/L时,原水铁砷比分别为35∶1,50∶1,52∶1和55∶1,能达到除铁效果且同时满足出水砷含量小于10μg/L的限值要求;根据氢氧化铁对砷的吸附机理,利用Freundlich吸附等温式建立了铁砷比与残余砷含量的数学模型,试验数据拟合结果与模型相吻合。此外,采用曝气氧化工艺处理铁砷复合污染地下水时,可以通过投加二价铁盐控制原水铁砷比,以实现同时去除铁砷的目的。     

砷及含砷废水的治理方案介绍

论述了砷及含砷废水的排放和造成的污染问题,并结合某工厂含砷废水的处理过程,从方案设计到运行效果作了详细介绍,指出该处理方案对其他相关含砷废水的达标处理有一定的借鉴意义。     

水中藻类污染物去除方法研究进展

重点介绍了藻类污染物的去除方法,内容包括：物理法、化学法、生物膜处理法和组合工艺法,评价了各种除藻方法的优缺点和适用范围,探讨了除藻技术的发展方向;并指出预臭氧化、生物处理、活性炭吸附处理组合工艺对叶绿素α的去除率可达100％,对色度、浊度、氨氮、有机物的去除效果最佳。     

饮用水除砷处理方法研究

依据国家饮用水水质卫生标准,对饮用水除砷处理方法的选择进行探讨.     

低成本吸附材料吸附水中砷的研究进展

介绍了砷污染的来源以及危害,传统处理方法的优劣及其应用限制和最新低成本脱砷吸附剂的研究进展.在水污染领域,低浓度污染水体一直都是较为棘手的问题,因为体量巨大无法统一处理.吸附技术,尤其是低成本吸附剂对于此类体量巨大的低浓度砷污染水体的脱砷具有极其重要的作用.从吸附剂原材料、吸附容量以及吸附等温线拟合效果方面,综述了低成...     

原子荧光法测定水中痕量砷的实验探讨

采用AFS-8120双道原子荧光光度计测定水中砷含量,测定结果表明:标准样品相对误差小于5%,仪器检出限为0.017 0μg/L,砷标准曲线的线性范围定在1.00μg/L~10.00μg/L之间的测定结果较准确,为今后日常水质分析砷的检测提供了可靠保证。     

Colorimetric method for the determination of arsenic in potable water

A colorimetric method for the determination of arsenic in potable water was developed with a limit of detection of 0.0005 mg l⁻¹. Arsenic(V) reacts quantitatively with potassium iodide in the presence of sulphuric acid and releases an equivalent amount of iodine, which imparts a pink colour to a carbon tetrachloride extract, this colour being measured at a predetermined wavelength of 515 nm. The method was used to differentiate between arsenic(V) and arsenic(III) and to analyse water samples from rivers, wells and lakes. No interference from arsenic(III), iron(III), chromium(VI) or lead(IV) was observed.     

碳酸盐岩处理酸性高砷煤矿废水的可行性研究

结合贵州省广泛分布的碳酸盐岩与酸性高砷煤矿废水的特点,探讨利用碳酸盐岩处理酸性高砷煤矿废水的可行性,体现了其经济性,促进了矿山环境的修复,从而减少地表环境的有毒有害物质的含量。     

黄河侧渗水砷超标问题的应急处理工艺研究

以采用黄河侧渗水为原水的柿园水厂现有常规净水工艺为基础,开展了水源突发性砷污染的应急处理工艺研究.结果表明,聚合硫酸铁对砷的混凝去除效果优于三氯化铁;液氯投加量为2.0 mg/L时,除砷效率均最佳;调节pH对砷去除效果的改善不明显.通过正交试验确定出适合黄河侧渗水砷去除的最佳参数:聚合硫酸铁投加量10 mg/L,硅酸钠投加量3.3 mg/L,液氯投加量2.0 mg/L,沉淀时间60 min.混凝剂的投加量是影响除砷效果的最显著因素.     

Organic arsenic removal from drinking water

Arsenic occurs in both inorganic and organic forms in water. Although various methods have been adopted to remove inorganic species of arsenic from drinking water, not much emphasis has been given to the removal of organic species of arsenic. In the present study column studies were conducted using manganese greensand (MGS), iron oxide-coated sand (IOCS-1 and IOCS-2) and ion exchange resin in Fe³⁺ form, to examine the removal of organic arsenic (dimethylarsinate) spiked to required concentrations in tap water. Batch studies were conducted with IOCS-2, and the results showed that the organic arsenic adsorption capacity was 8 μg/g IOCS-2. Higher bed volumes (585 BV) and high arsenic removal capacity (5.7 μg/cm³) were achieved by the ion exchange resin among all the media studied. Poor performance was observed with MGS and IOCS-1.     

High levels of inorganic arsenic in rice in areas where arsenic-contaminated water is used for irrigation and cooking

Rice is the staple food for the people of arsenic endemic South (S) and South-East (SE) Asian countries. In this region, arsenic contaminated groundwater has been used not only for drinking and cooking purposes but also for rice cultivation during dry season. Irrigation of arsenic-contaminated groundwater for rice cultivation has resulted high deposition of arsenic in topsoil and uptake in rice grain posing a serious threat to the sustainable agriculture in this region. In addition, cooking rice with arsenic-contaminated water also increases arsenic burden in cooked rice. Inorganic arsenic is the main species of S and SE Asian rice (80 to 91% of the total arsenic), and the concentration of this toxic species is increased in cooked rice from inorganic arsenic-rich cooking water. The people of Bangladesh and West Bengal (India), the arsenic hot spots in the world, eat an average of 450 g rice a day. Therefore, in addition to drinking water, dietary intake of arsenic from rice is supposed to be another potential source of exposure, and to be a new disaster for the population of S and SE Asian countries. Arsenic speciation in raw and cooked rice, its bioavailability and the possible health hazard of inorganic arsenic in rice for the population of S and SE Asia have been discussed in this review.     

Microbial transformations of arsenic in lake ohakuri, New Zealand

The concentration and chemical speciation of arsenic in the waters and sediments of Lake Ohakuri, New Zealand were examined. Mixed microbial populations from the sediments were tested in vitro for their ability to mediate redox transformations of inorganic arsenic.Under aerobic conditions the mixed microbial cultures were found to be able to reduce arsenic(V) to arsenic(III) and also to oxidize arsenic(III) to arsenic(V). Under anaerobic conditions only reduction of arsenic(V) to arsenic(III) was observed. Four species of sediment fungi were isolated, grown aerobically and all were found capable of reducing arsenic(V) to arsenic(III).The role of microbial heterotrophs in determining the observed mobility and speciation of arsenic in Lake Ohakuri is discussed.     

浅谈省煤器汽水冲击的原因及消除

从省煤器产生汽水冲击的原因着手分析,提出消除省煤器汽水冲击现象的方法和省煤器在运行中应注意的问题,指出只有认识了解汽水冲击产生的物理过程及其原因,才可减少汽水冲击事故的发生。