浸没式超滤在钢铁废水处理中的应用

随着运行时间的延长,跨膜压差上升,进水投加Cl O2后,上升趋势变缓。通过对浸没式超滤运行的研究得出了反洗方式及维护性清洗周期。浸没式超滤对来水中COD、Fe和浊度去除效果明显,产水水质符合一级反渗透进水要求。     

膜法水处理技术在钢铁废水回用中的应用

钢铁企业的污(废)水由于污染物成分复杂,在进行反渗透脱盐处理时,若只采用常规水处理工艺(如:中和、生化处理、混凝、澄清、介质过滤等)作为反渗透的预处理,往往无法满足反渗透系统的进水水质要求,造成反渗透装置的快速污堵及频繁清洗。在常规水处理工艺的基础上结合超滤处理工艺作为反渗透的预处理,则能够大大降低反渗透装置的污堵速度及清洗频率,保证反渗透系统的长期、稳定运行,为钢铁企业提供可替代新鲜水、锅炉用水、工业工艺用水的高品质回用水。     

膜处理技术在天钢生产废水回用系统中的应用

为降低用水成本,将膜处理技术应用于天钢生产废水回用系统中。该系统采用超滤、纳滤、反渗透等膜处理工艺,对生产废水处理中心产生的浓盐水进行减量化处理:回收再生生产用水,减少自来水用量,降低了吨钢耗水量;将超浓盐水全部用于转炉精炼渣焖渣和喷洒。该工艺使浓盐水得到了有效的资源化利用,节能减排效果明显,取得了较好的经济效益、环境效益和社会效益。     

反渗透技术在给水项目中的应用

1.反渗透水处理工艺流程的设计 根据沧州中铁装备制造材料有限公司附近地表水水质较复杂、含盐量偏高的水质特点及该钢厂生产用水的水质要求,此套水处理系统设置了以沉淀池＋多介质过滤器＋自清洗过滤器为主的机械过滤装置,加上超滤系统作为反渗透的预处理系统,以反渗透系统为主脱盐装置的水处理系统设计。首先将地表水引入沉淀池中,期间添加絮凝剂,     

赤峰金剑铜业技改项目生产原水处理工艺初探

赤峰金剑铜业技改项目生产原水采用城市中水。该中水水质平均硬度为381.09 mg/L、碱度217.72 mg/L、COD 32.25 mg/L,进水水质相对较好。为保证生产用水的安全性,需对中水进行处理。设计采用"预处理+超滤+二级膜处理+EDI深度处理"的流程,经处理后的一级反渗透出水用作循环水补充水,另一部分一级反渗透出水经二级反渗透及EDI深度处理后出水用作锅炉补给水。采用工艺处理后,产水水质、排水水质均可达到国家标准。     

黑龙江砂宝斯金矿床水资源质量评价

砂宝斯金矿床已进入矿山建设与开发阶段,区内水资源的质量对矿山建设和开发必然会产生一定的影响。通过对矿区内水资源的水质、细菌及放射性等进行分析测试,分别从生活饮用水、锅炉用水和建筑用水3个方面对水环境质量进行了评价。研究区内地表水水质较好,符合饮用水标准,但地下水水质较差,砷、铁、锰和耗氧量等普遍超标;区内水资源均为软垢水或软硬垢水及不起泡的水;小东沟河上游为非腐蚀性水,其他水点均为半腐蚀性水;区内地下水与地表水无侵蚀性。     

超滤作为反渗透预处理的应用研究

对超滤作为反渗透预处理工艺实际生产运行数据的分析,考察了该系统的可靠性和稳定性,得出超滤适用于反渗透预处理工艺的结论。     

超滤-反渗透技术在高炉冷却水制备中的应用

阐述了超滤-反渗透技术在高炉冷却水制备中的应用情况,超滤的产水能够满足反渗透系统对水质的要求,反渗透设备运行稳定,出水性能良好,满足高炉高强度冶炼要求。同时,对超滤和反渗透运行情况及其在运行过程中出现的问题进行了分析和讨论。     

铜冶炼过程中硫化砷渣综合利用技术

针对铜冶炼过程中产出的硫化砷渣的处理工艺进行了评述,并对新研究开发的酸性加压氧化浸出工艺进行了详细介绍.硫化砷渣经酸性加压氧化浸出后,铜、砷及铼的浸出率均达到95%以上,硫则以单质形态进入浸出渣中.浸出液经二氧化硫还原冷却脱砷进而可生产优质As2O3,脱砷后液经溶剂萃取提取铼用于生产高铼酸铵,萃余液再经蒸发结晶可以生产硫酸铜.由此,硫化砷渣中的铜、砷、铼、硫都得到综合回收.     

全膜法除盐水系统技术改造

全膜法除盐工艺在型钢除盐水生产应用中效果欠佳。型钢化学水首先采取多介质、活性炭、超滤、保安过滤的预处理和反渗透加阴阳床的除盐工艺,改进原二级反渗透工艺缺陷,保证型钢区域除盐水的优质足量供应。     

砷酸铁@四氧化三铁磁性固砷材料的设计及稳定化研究

目前工业中的固砷的方法主要是铁法固砷，即使用稳定的晶型砷酸铁除砷固砷。为了对砷酸铁固砷进行优化研究，使用惰性四氧化三铁对砷酸铁晶体进行包覆处理，增强其耐酸碱能力，实现稳定化固砷的目的。通过对不同反应pH、铁砷摩尔比、反应温度所制备复合材料稳定性的研究，确定最优化固砷条件。最后通过毒性浸出试验(TCLP)评估了四氧化三铁包覆后的磁性固砷材料在极端环境下的长期稳定性。结果表明：使用四氧化三铁稳定化处理后的砷酸铁材料，能够达到国家危废处理相关标准，是合格的固砷材料。     

Removal of Arsenic from Ground Water by Manganese Dioxide–Coated Sand

In a laboratory study, manganese dioxide–coated sand (MDCS), prepared by reacting potassium permanganate with manganese chloride under an alkaline condition and in the presence of sand, showed promise as a medium for use in small systems or home-treatment units in developing areas of the world, for removing arsenic(III) and arsenic(V) from ground water. In ten cycles of downflow column tests [bed depth 400 mm; empty-bed contact time 74 min; influent arsenic 0.5 mg As∕L of arsenic(III) and 0.5 mg As∕L of arsenic(V)], breakthrough bed volumes at the World Health Organization guideline value of 0.01 mg As∕L for arsenic in drinking water were in the range of 153–185 per cycle. During regeneration (backwashing with 2 L of a 0.2 N sodium hydroxide solution), 85.0% of the removed arsenic was recovered in the first cycle, and 94.6–98.3% was recovered in subsequent cycles. A low-cost, simple home arsenic removal unit, containing 6 kg (4 L) of the MDCS medium and operated at 6 L∕h, produced 740 and 700 L of water in two cycles of runs when the influent arsenic concentration was 0.5 mg As∕L of arsenic(III) and 0.5 mg As∕L of arsenic(V). No arsenic(III) or leaching of manganese from the medium was detected in the effluent. A detailed study addressing the effects of some important factors (water pH, concentration and type of competing anions, and cations) on the process is needed. The home arsenic removal unit should be subjected to field trials to assess the long-term effects on performance.     

Drinking water supply with reference to geogenic arsenic contamination

Geogenic Arsenic in Drinking Water. Drinking water production of surface spring water in southern Lower Saxony (Niedersachsen, Germany) was reduced because of microbiological contaminations and unreliably variable water reserves. Surface spring water in general has a low arsenic content. As a consequence ground water has been increasingly used for drinking water. Thus, high geogenic concentrations of arsenic in the central "Buntsandstein" in southern Lower Saxony caused high arsenic contents in the groundwater. Under the regulation of the German Drinking Water Ordinance (1986) the limit for total arsenic (40 micrograms/l) was exceeded in 2% of 150 fountains, wells and sources in southern Lower Saxony. Because of the well-known cancerogenic potential of arsenic the limit for total arsenic in drinking water was reduced from 40 micrograms/l to 10 micrograms/l suspending the new standard value until January 1996. This regulation based on new calculations revealing a skin cancer risk of roughly 6:10,000 and a mortality risk of roughly 1:10(6) in respect of lifetime in case of arsenic concentrations of 10 micrograms As/l drinking water. After that limit change 40% of 150 wells and sources in southern Lower Saxony exceeded the arsenic limit of 10 micrograms/l drinking water. As a matter of fact, it became necessary for a large number of water supply works to eliminate arsenic from the drinking water by technical means or to dilute drinking water with high concentrations of arsenic.     

Chrono-neuroendocrine markers of the aging brain

OBJECTIVE: This Belgian study assessed the geographical and temporal differences in the exposure of the population to inorganic arsenic, a known carcinogen. METHODS: In the CadmiBel study (1985-9) the 24 h urinary arsenic excretion was measured, as an index of recent exposure, in industrialised cities (Liège: n = 664, Charleroi: n = 291), in a rural control area (Hechtel-Eksel: n = 397), and in rural districts in which the population had possibly been exposed through the drinking water or the emissions of nonferrous smelters (Wezel: n = 93, Lommel: n = 111, and Pelt: n = 133). In the PheeCad study, in 1991-5, the rural areas (n = 609) were re-examined together with an urban control area (Leuven: n = 152). RESULTS: The CadmiBel results showed that after adjustment for sex, age, and body mass index, the 24 h arsenic excretion was on average low in Liège (91 nmol), Charleroi (155 nmol), Hechtel-Eksel (144 nmol), and Wezel (158 nmol), whereas the highest excretions were found in Lommel (570 nmol) and Pelt (373 nmol). During the PheeCad study, the mean 24 h arsenic excretion in the rural areas ranged from 81 to 111 nmol. This was lower than six years earlier and similar to the excretion in the control town (108 nmol). Longitudinal studies in 529 people living in the rural areas confirmed that their 24 h arsenic excretion had decreased (P < 0.001) from 222 to 100 nmol. As well as the drinking water, industry was likely to be a source of the increased exposure in Lommel and Pelt in 1985-9, because at that time the urinary arsenic excretion did not follow the regional differences in the arsenic content of the drinking water, because the fall in the arsenic excretion over time coincided with the implementation by industry of stricter environmental regulations, because in individual subjects the urinary arsenic excretion was inversely correlated with the distance to the nearest smelter, and because an increased arsenic excretion was only found downwind from the main smelter. The official network that monitors the arsenic concentration in airborne and fall out dust did not detect the high exposure in Lommel and Pelt between 1985 and 1989. CONCLUSION: This study highlights the necessity to validate environmental monitoring programmes by directly estimating the internal exposure of the population.     

Manganese Amended Activated Alumina for Adsorption/Oxidation of Arsenic

In a laboratory study, manganese amended activated alumina (MAA), prepared by calcining (400°C) manganese acetate-impregnated activated alumina, showed promise as a more effective medium than activated alumina (AA) for use in small municipal drinking water systems or point-of-use treatment, for removing arsenic [As(III) and As(V)] from groundwater. Batch adsorption/oxidation kinetic tests indicated that in fixed-bed operation, with a bed flowthrough time of 10–20?min, MAA would be a more effective medium than AA in removing arsenic [As(V), As(III), and As(III) and As(V) (present together)] from groundwater. In three cycles of downflow column test [bed depth 200?mm; bed flowthrough time 20?min; influent arsenic 1.0–0.6?mg/L As(III) and 0.4?mg/L As(V)], breakthrough bed volumes at the World Health Organization guideline value of 0.01?mg/L for arsenic in drinking water were 580, 550, and 485, and 825, 770, and 695, respectively, for AA and MAA. During regeneration (backwashing with a sodium hydroxide solution), 84–88% (for AA) and 86–89% (for MAA) of the removed arsenic was recovered. Manganese concentration in the MAA column effluent was low (below 0.02?mg/L). A detailed study addressing the effects of some important factors (water pH, concentration and type of competing ions, and fouling by organics) on the process is needed.     

铜旋浮冶炼电收尘烟灰脱砷工艺研究

阳谷祥光铜业有限公司采用旋浮熔炼工艺冶炼铜精矿,随着入炉铜精矿含砷的提高,电收尘烟灰中的含砷量也随之提高,砷在系统中不断循环,使阳极板中砷含量超标,影响阴极铜的质量.公司利用前期试验期间的保存样品进行了砷提炼试验,该提炼工艺包含水浸和酸浸两个过程.水浸试验表明铜烟尘经过水浸,烟灰中67.5％的铜和69.9％的锌被优先脱...     

A/A/O/O工艺在包钢焦化废水处理中的应用

焦化废水处理是焦化厂环境污染治理工作中的一个难题.包钢焦化厂在酚氰废水处理站改扩建工程中采用了国内先进的A/A/O/O工艺.该工艺不但能很好地去除废水中的酚、氰、CODcr等污染物,还能有效降解氨氮浓度,使之达到国家二级排放标准.     

Arsenic Removal by a Colloidal Iron Oxide Coated Sand

A novel treatment process for arsenic removal from contaminated groundwater has been developed for use as a reactive barrier or a small drinking water treatment unit. In this study, modified porous media was made by the deposition of colloidal iron oxide onto sand grains at intermediate pH and ionic strength. Kd values from column experiments were 0.016–0.37?L/kg for As(III) and 0.023–0.85?L/kg for As(V), being lower than those of batch experiments (0.50 and 1.30?L/kg for As(III) and As(V), respectively) due to lower availability of surface adsorption sites in the packed column. Media-independent Kd values reflect the enhancement of arsenic adsorption with an increase of colloidal iron oxide coated sand fraction, apparently due to adsorption equilibration during arsenic transport under the same flow column conditions. The heterogeneous composition of two groundwater samples also reduced arsenic adsorption. Therefore, arsenic elution near the initial breakthrough was regulated by available adsorption surface in a porous coated sand media as well as the effects of competing oxyanions. The exhaustion of adsorption capacity near the critical contamination level is sensitive to geochemical and remedial properties of the contaminants.     

Leaching of molybdenum and arsenic from uranium ore and mill tailings

A sequential, selective extraction procedure was used to assess the effects of sulfuric acid milling on the geochemical associations of molybdenum and arsenic in a uranium ore blend, and the tailings derived therefrom. The milling process removed about 21% of the molybdenum and 53% of the arsenic initially present in the ore. While about one-half of the molybdenum in the ore was water soluble, only about 14% existed in this form in the tailings. The major portion of the extractable molybdenum in the tailings appears to be associated with hydrous oxides of iron, and with alkaline earth sulfate precipitates. In contrast with the pattern seen for molybdenum, the partitioning of arsenic into the various extractable fractions differs little between the ore and the tailings.