青龙县铁矿企业对生态环境的影响及防治对策

青龙县部分铁矿企业的无序开采给水土保持、生态环境带来了严重危害。落实科学发展观，以生态科学为指导，建设资源节约型、环境友好型的铁矿开采企业迫在眉睫。为此提出以下防治对策：加大执法力度，加强对铁矿企业的监管；编报水土保持方案，严格审批服务；因地制宜，采取水土保持措施；强化铁矿企业生态环境保护，推广尾矿综合利用。     

Microbially Mediated Redox Cycling at the Oxic–Anoxic Boundary in Sediments: Comparison of Animal and Plants Habitats

Microorganisms are responsible for the bulk of transformations that occur in surficial sediments. They are most active at redox boundaries where they can benefit from access to various oxidants and reductants generated during redox cycling events. To illustrate the dynamics of microbially mediated processes, especially those involving sulfur and metal cycles, processes were compared in habitats either bioturbated by a capitellid worm or inhabited by a salt marsh grass. The presence of macrofauna and macroflora greatly altered the three-dimensional array of redox gradients in sediments, but the type and form of reductants and oxidants provided varied greatly; clastic sedimentary infauna subducted solid phase organic material and iron oxides, whereas plant roots released dissolved organic matter and oxygen. These differences resulted in a bioturbated system that exhibited a rapid sulfur cycle (residence time of minutes), but a slower iron cycle (days), whereas vegetation caused a slow sulfur cycle and rapid iron cycle. Alteration of sediments by higher life forms also greatly affected the composition and relative abundances of sedimentary bacteria, even on short time scales. Although redox cycling at interfaces can be somewhat predictable, variations in response to biological and physical perturbations demonstrated wide differences in the dynamics of redox-mediated processes.     

Chemical immobilisation of arsenic in contaminated soils using iron(II)sulphate—advantages and pitfalls

Chemical immobilisation of inorganic contaminants by increasing the sorption capacity of soils and/or promoting the formation of sparingly soluble precipitates may be a cost-effective approach to counteract groundwater pollution. This study focuses on the enhanced retention of arsenic in two contaminated soils by addition of solid iron(II)sulphate. Four lab-scale column experiments were performed under unsaturated conditions with subsoil material sampled at a former timber preservation site and a pigment production plant. Arsenic effluent concentrations indicated 89.9 to 99.8% immobilisation in the treated columns. Sequential extractions showed a shift in contaminant binding forms towards the iron(hydr)oxide and residual fractions. Possible immobilisation mechanisms are the precipitation of FeAs phases, the formation of inner sphere complexes, and/or the occlusion of arsenic in newly formed amorphous/crystalline iron oxides. Bromide breakthrough curves point to the fact that the addition of iron(II)sulphate only moderately affects soil hydraulic properties. In contrast to reduced emissions of arsenic, increased seepage water concentrations were observed for other trace elements (e.g., cobalt, nickel, zinc). Mass balances indicate that this effect is primarily related to the temporary pH-drop caused by the oxidation of ferrous iron. The results show that chemical immobilisation using iron(II)sulphate is a promising way to protect groundwater quality at sites contaminated with timber preservation and pigment production remnants. As a prerequisite, optimum amendment levels need to be established and practical/field tests should be accompanied by a monitoring for a broad range of relevant trace elements.     

含铁物质对燃煤污染特性的影响

利用DTA-TG-DTG设备实验研究了FeCl₃、FeCl₂和Fe₂O₃等含铁物质对燃煤污染特性的影响.结果表明:实验所用的几种含铁化合物均能够改变燃煤污染物的排放规律,但不同种类的含铁物质对燃煤污染特性影响机理不同,所取得的污染物减排效果也不同.在煤燃烧以及煤中S与N向SO₂及NO转化的过程中,FeCl₃既起到催化剂的作用,同时又起吸收剂的作用.FeCl₃催化作用表现在降低了SO₂和NO生成反应的表观活化能,使SO₂和NO能够在较低温度时迅速形成,加快了SO₂和NO生成反应的速率.FeCl₃的催化效果与S在煤中的存在形态有关.FeCl₃的吸收作用表现在FeCl₃本身能够参与SO₂的吸收反应生成FeSO₄或Fe₂(SO₄)₃.此外,FeCl₃还能够改变CO的排放特性,即能够改变煤的燃烧特性.FeCl₂对烟气中SO₂、NO和CO排放特性的影响与FeCl₃相似,但影响效果比FeCl₂₃略差.Fe₂O₃也能够降低烟气中SO₂和NO的体积分数,但Fe₂O₄只是吸收剂,对SO₂和NO的生成过程没有催化作用.Fe₂O₃对CO排放特性的影响不大.     

催化铁内电解-生化法处理印染废水

纺织印染废水水质变化大、色度高,直接生物处理难度大.采用催化铁内电解法对浙江某地区的印染废水进行预处理,有效地去除了对生物有抑制的有机物,为后续的生化处理创造了有利条件,COD_Cr去除率达到85%;过去难以解决的色度问题也得到了有效的解决,可去除废水色度90%以上.另外,简要探讨了金属粒径,pH,温度等因素对去除有机物的影响.近40 d的连续流试验证明,内电解-生化工艺具有处理效果好、出水水质稳定、工艺设备简单、操作管理方便、能耗低等特点,是处理印染废水的有效方法之一.      

硝基苯类化合物在铜电极上的电还原特性和还原机理

采用循环伏安法,对硝基苯类化合物在铜电极表面上的电还原特性进行了研究,评价了它们在铜电极上的电还原反应活性,分析了此类化合物在铜电极上的还原机理,并且讨论了电还原反应活性和此类化合物结构之间的关系．结果表明,硝基苯类化合物在铜电极表面有还原电位,也就是说,能在铜电极表面被直接还原．     

Disintegration of waste activated sludge by different applications of Fenton process

Oxidative disintegration of municipal waste activated sludge (WAS) using conventional Fenton (Fe²⁺ + H₂O₂, CFP) and Fenton type (Fe⁰ + H₂O₂, FTP) processes was investigated and compared in terms of the efficiency of sludge disintegration and enhancement of anaerobic biodegradability. The influences of different operational variables namely sludge pH, initial concentration of Fe²⁺ or Fe⁰, and H₂O₂ were studied in detail. The optimum conditions have been found as catalyst iron dosage = 4 g/kg TS, H₂O₂ dosage = 40 g/kg TS and pH = 3 within 1 h oxidation period for both CFP and FTP. Kinetics studies were performed under optimal conditions. It was determined that the sludge disintegration was happened in two stages by both processes: rapid and subsequent slow disintegration stages and rapid sludge disintegration stage can be described by a zero-order kinetic model. The effects of oxidative sludge disintegration under the optimum conditions on anaerobic digestion were experienced with biochemical methane potential (BMP) assay in batch anaerobic reactors. Total methane production in the CFP and FTP pre-treated reactors increased by 26.9% and 38.0%, relative to the untreated reactor (digested the raw WAS). Furthermore, the total chemical oxygen demand reductions in the pre-treated reactors were improved as well.     

生物除锰除铁滤池对低氟的去除效果研究

氟元素与人体健康关系比较密切,其含量过高和过低对人体健康都有危害,因而对地下水中氟污染物的研究,意义重大。为此人工配制了含F-为1．00～3．00mg／L、不同Mn2＋、Fe2＋浓度的原水,并通过已经培养成熟的生物除锰除铁滤池进行过滤。结果表明,进水pH（5．5～7．5）为中性条件下,滤池对氟具有长期稳定的微弱去除效果。在低pH（2．5—3．5）条件下,出水F-浓度在短时间内达到生活饮用水标准。     

Effects on nano zero-valent iron reactivity of interactions between hardness, alkalinity, and natural organic matter in reverse osmosis concentrate

Nanoscale zero-valent iron （NZVI） is considered to have potential to reduce nitrate in the concentrate generated by high pressure membrane processes aimed at water reuse. However, it is necessary to verify the effect of the matrix components in the concentrates on NZVI reactivity. In this study, the influence of hardness, alkalinity, and organic matter on NZVI reactivity was evaluated by the response surface method （RSM）. Hardness （Ca/＋） had a positive effect on NZVI reactivity by accelerating iron corrosion. In contrast, alkalinity （bicarbonate; HCO3） and organic matter （humic acid; HA） had negative effects on NZVI reactivity due to morphological change to carbonate green rust, and to competitive adsorption of HA, respectively. The validity of the statistical prediction model derived from RSM was confirmed by an additional confirmation experiment, and the experimental result was within the 95% confidential interval. Therefore, it can be indicated that the RSM model produced results that were statistically significant.     

攀钢西昌钢钒有限公司环保信息化建设探索

攀钢集团公司2009年在凉山州西昌市投资建设了攀钢西昌钒钛资源综合利用项目,成立了攀钢西昌钢钒有限公司。项目组成之一的信息化系统建设中,能源环保系统作为一子系统同步配套建设。介绍了能源环保子系统中环保信息化系统设计架构、功能、技术路线等,可作为环保信息化系统设计的借鉴和参考。