焙烧颗粒膨润土的制备及其对废水中Mn~(2+)的吸附研究

对膨润土颗粒吸附剂进行了制备、焙烧改性,并通过静态吸附试验,对制备的改性吸附剂处理矿山废水中的Mn2+进行了试验研究。结果表明,颗粒吸附剂制备、焙烧改性的最佳条件是:膨润土与蒸馏水质量比为25∶18、膨润土颗粒的粒径为2mm、焙烧温度为500℃、焙烧时间为1.5h。在pH 6,温度为25℃,转速50r/min,进水Mn2+105.86mg/L,吸附剂投加量0.28g/L和吸附时间60min的试验条件下,Mn2+的去除率达96%以上,且吸附剂对Mn2+的吸附符合Langmuir吸附方程。     

无机柱撑膨润土对有机锡废水COD的吸附研究

利用原土、羟基铁膨润土和羟基铁铝柱撑膨润土,进行了吸附有机锡废水中CODcr的试验.研究了膨润土投加量、吸附pH、时间和等温线的变化规律.结果表明,达到吸附平衡的时间为2 h;随着吸附pH由小到大的变化,CODCr的吸附去除率在一定范围内波动;膨润土的投加量宜大于4 g/L;吸附符合Henry等温式;膨润土的层间距、吸附位的数量及活性是决定对吸附性能的关键因素;吸附容量的大小和吸附作用的强弱顺序为:羟基铁铝膨润土＞羟基铁膨润土＞原土.     

改性膨润土处理重金属离子废水的研究进展

重金属离子对人体有害,在废水中很难处理,利用廉价吸附剂有效处理重金属离子,既经济又环保。膨润土价廉易得,比表面积大,吸附性好,是一种天然的矿物质吸附剂。文章总结了膨润土吸附重金属离子的机理,并分析了改性膨润土在吸附重金属离子方面的研究进展及存在问题,并提出了解决办法。     

三维电极流化床对印染废水降解脱色处理

试验在二维电极之间填充锰砂形成三维复极电极,在鼓气搅拌的传质情况下,对含酸性大红3R 的印染模拟废水进行降解脱色处理,从而形成固-液-气三相三维电极流化床废水处理装置。考察了槽电压、支持电解质浓度、鼓气搅拌传质等因素,对二维和三维两种反应装置处理染料脱色率的影响。研究表明：三维电极流化床装置比二维电极电解槽脱色速度快、处理效率高,而且,脱色率可提高30%～50%。紫外-可见光吸收光谱分析表明,三维电极流化床不仅能对酸性大红3R 的生色基团进行降解脱色,对萘环不饱和共轭体系也具有降解破坏作用。     

红黏土膨润土塑性件混凝土在土石坝防渗工程中的应用研究

红黏土膨润土塑性件混凝土是一种典型的塑性工程材料,在土石坝防渗工程中利用红黏土膨润土塑性件混凝土制作的防渗墙,具有一定的抗压能力、抗渗能力和较低的弹性模量,其参数均可以通过调节红黏土含量进行人为控制,以达到抑制渗漏、管涌的目的,且能承受一定荷载。在水泥含量一定(150 kg/m~3)的条件下,对红黏土含量分别为0、30、60、90、120、150、180和210 kg/m~3的红黏土膨润土塑性件混凝土进行单轴压缩试验及渗透系数试验,分析不同红黏土含量下红黏土膨润土塑性混凝土防渗墙对土石坝力学行为及防渗效果的影响效应,以期为实际工程提供参考和借鉴。     

高锰酸盐指数(酸性法)在不同条件下的测定探讨

影响水中高锰酸盐指数含量测定结果的因素主要有水浴的温度、时间和溶液的酸度等等。采用高锰酸盐指数酸性法研究:在不同时间、不同酸度条件下的高锰酸盐指数的测定值。经过大量研究表明:同一时间下,随着酸性的增大,高锰酸盐指数就越大,同一酸性条件下,水浴反应时间越长,高锰酸盐指数越大;在测定时,水浴时间控制在30分钟,加入5m L硫酸(1+3)滴定时,样品的温度控制在60℃-80℃,这样能把高锰酸盐指数的测定结果做到最精确。     

锂渣对酸性Cr(Ⅵ)的吸附机理及固化

为了去除工业废水的六价铬,采用工业废渣——锂渣来做吸附试验,探讨p H值、温度、初始浓度对去除率的影响。经过实验发现,去除Cr6+的最佳p H值范围是3.0~4.0,并且随着Cr6+逐渐被吸附,溶液的p H值逐渐升高;在不同温度下,颗粒内扩散模型、准一级速率方程、准二级速率方程对Cr6+的吸附动力学方程的相关较好,以温度为40℃最优,且符合Langmuir和Freundlich等温吸附模型,最大吸附量达13.785mg/g。结果表明:锂渣中Fe O的含量下降了0.2%,Cr3+和Cr6+的含量分别提高了0.2022%和0.0309%。说明锂渣对酸性Cr6+的吸附包含了还原与吸附两个作用,锂渣中的Fe O充当了还原剂,降低了Cr6+的浓度,随着锂渣的吸附作用,将Cr3+从水中去除。将吸附Cr6+的锂渣与水泥作为胶凝材料加水成型试件,养护3个月后测试出Cr6+的溶出量均满足我国地表水III类和地下水III类规定的要求。     

粉煤灰制备聚硫酸铝铁混凝剂及处理乳品废水的效果

以铝铁的溶出率为评价指标,衡量直接酸溶、添加助溶剂酸溶和碱熔焙烧后再酸溶等三种方法提取粉煤灰中金属元素的能力。结果表明,试验条件下,碱熔焙烧后再酸溶效果最好,溶出液中Al、Fe浓度分别为5 734 mg/L、2 336 mg/L,相应溶出率为15.5%、26.4%。利用溶出液通过慢速加碱法可制取聚硫酸铝铁混凝剂,对乳品废水的COD_(Cr)去除率为57.5%,SS去除率为93.1%。     

氨基修饰磁性蒙脱土对水中As(Ⅴ)的吸附特性研究

为解决粉末蒙脱土使用后难以泥水分离以及材料吸附能力较差等问题,通过共沉淀法制备Fe3O4@蒙脱土复合材料,并通过氨基修饰磁性蒙脱土(N-Fe3O4@MT),研究了初始pH、投加量、共存离子、吸附时间和温度等因素对N-Fe3O4@MT去除As(Ⅴ)的影响,探讨吸附动力学和吸附等温线特征.通过元素分析、扫描电镜(SEM)、...     

超声波辅助法制备纳米FeS处理酸性含铬废水工艺研究

针对排放酸性含铬废水所产生的环境污染问题,采用超声波辅助法制备纳米FeS,用于处理酸性含铬废水。通过正交试验确定了超声波辅助法制备纳米FeS的最佳制备条件,并讨论了反应时间、pH值和Cr(Ⅵ)初始浓度对纳米FeS处理酸性含铬废水的影响。结果表明：超声波辅助法制备纳米FeS的最佳制备条件为超声波频率40 kHz、超声波处理时间10 min、制备反应温度15 ℃,在此条件下Cr(Ⅵ)和总铬的去除率分别为81.03%、63.40%;当反应时间达到50 min后,纳米FeS对酸性含铬废水的处理效果趋于稳定,酸性条件能促进纳米FeS对Cr(Ⅵ)和总铬的去除;随着Cr(Ⅵ)初始浓度的升高,纳米FeS对Cr(Ⅵ)和总铬的单位去除量逐渐增大,当Cr(Ⅵ)初始浓度为300 mg/L时,Cr(Ⅵ)和总铬的单位去除量分别可达486.65和383.55 mg/g。可见,超声波制备的纳米FeS可以有效去除废水中的铬离子,为今后实际工程应用提供了一定的理论指导。     

Preparation and characterization of CTAB-HACC bentonite and its ability to adsorb phenol from aqueous solution

A novel type of adsorbent was prepared by modifying bentonite with N-2-hydroxypropyl trimethyl ammonium chloride chitosan (HACC) with cetyl trimethylammonium bromide (CTAB). The adsorbent was named CTAB-HACC bentonite. Its characteristics were investigated using thermogravimetric, Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction. The adsorption of phenol onto CTAB-HACC bentonite was evaluated by changing various parameters, such as contact time, adsorbent dosage, initial pH of the solution, and temperature. The maximum adsorption was observed at pH 12. Adsorption of phenol on CTAB-HACC bentonite favored at lower temperature and established the equilibrium in 30 min. The adsorption efficiency reached 82.1%, and the adsorption capacity was 7.12 mg/g from the phenol solution with a concentration of 500 mg/L at pH 12.0 and 20 degrees C.     

Fenton试剂对铁锰矿井废水处理的实验研究

使用Fenton试剂对铁锰矿井水进行处理试验,论述了反应温度、H2O2的投加量、pH、反应时间对Fenton试剂处理矿井水的影响,讨论了Fenton试剂处理酸性矿井废水的机理。结果表明:芬顿试剂对铁锰矿井水中锰的去除效率很高,矿井水中的Fe2+能与H2O2形成Fenton试剂后产生的具有强氧化性的.OH能有效处理矿井水中的Mn2+。对于原水Mn2+的初始浓度为2 mg/L,Fe2+的初始浓度为250 mg/L,pH为5,当控制反应温度为25℃,H2O2的投加量为8 mmol/L,调节pH值为4.5,反应时间为10 m in,Mn2+去除效率可以达到78.1%以上。     

矿石黏土类物质、铁锆化合物对磷吸附影响因素研究进展

介绍了水中含磷的危害及通过比较选择吸附法作为一种高效、低能耗的除磷方法,吸附剂及其特点和金属类氧化物、黏土矿石类、活性炭吸附材料的吸附原理。详细阐述了反应温度、反应时间、反应pH值、共存离子对矿石黏土类物质和铁锆化合物吸磷过程的影响:反应温度主要通过影响分子热运动从而影响到吸附材料吸磷效果;对任何吸附材料吸磷都需要一定的反应时间来达到最佳效果;反应pH值主要通过影响溶液中离子浓度、种类及吸附材料表面所含的离子与其反应从而影响到吸附材料吸磷效果;共存离子的存在可能会提高库仑力和磷酸盐活性部位竞争力。同时也阐述了吸附剂用量、磷的初始浓度、电解质、吸附材料粒径对吸磷效果的影响。今后对吸附磷材料的研究应重点关注改性材料及复合材料。     

Pb~（2＋）在天然膨润土上的吸附动力学研究

采用静态法探讨了天然膨润土吸附废水中Pb2＋的主要影响因素及动力学。研究表明,在实验条件下,当天然膨润土用量增加时,吸附量随之减少。而当初始pH值在4～6变化时,吸附量随着pH值的增大而增加。此外,当温度或Pb2＋初始浓度升高时,吸附量也随之增大。由于反应速度较快,吸附60min后基本达到平衡,吸附90min后天然膨润土对Pb2＋的吸附量为6.52～19.15mg/g。吸附动力学规律遵从Lagergren准二级反应模型。     

Degradation of organic dye using zero-valent iron prepared from by-product of pickling line

In this study, zero-valent iron (ZVI) was produced using iron oxide that is a by-product of a pickling line at a steel works. The reaction activity of the produced ZVI was evaluated through a series of decomposition experiments of Orange II aqueous solution. The size of ZVI particles increased with reduction temperature due to coalescence. Correspondingly, the specific surface area of ZVI decreased with increasing reduction temperature. The decomposition efficiency of synthesized ZVI particles was higher at a lower pH. In particular, no significant decomposition reaction was observed at pH of 4 and higher. The rate of the ZVI-assisted decomposition of Orange II was increased by addition of H2O2 at pH of 3, whereas it was reduced by addition of H2O2 at a higher pH of 6. Nevertheless, simultaneous use of ZVI, UV and H2O2 led to a considerable increase in the decomposition rate even at a high pH condition (pH = 6).     

Bacillus sp.处理锑矿选矿废水的优化试验

用某芽孢杆菌属微生物(Bacillus sp.)处理锑矿选矿废水。通过正交实验,研究该微生物在处理锑矿选矿废水过程中微生物接种量、pH值、处理时间、温度对去除效果的影响。结果表明:Bacillus sp.对废水中锑的去除效果影响程度由大到小的顺序为:微生物接种量、pH值、处理时间、温度;最优实验条件:微生物接种量为5%、pH值为2.5、处理时间为3d,处理温度为30℃。     

湿式氧化技术处理化工废水的研究

采用湿式氧化技术处理在生产磺胺间二甲氧嘧啶过程中产生的高浓度有机废水。在反应温度为250℃,初始ρ(COD)为4 575 mg/L,反应时间为2 h,pH值为7~8时,采用湿式双氧水氧化和催化湿式氧化,COD去除率分别为78.3%和92.0%,表明催化湿式氧化具有较好的COD去除效果。同时考察了催化湿式氧化中反应温度、反应时间、废水pH值对COD去除率的影响。     

Heterogeneous catalytic oxidation of hypophosphite by H2O2: pH effect.

Phosphorus chemicals control key aspects of eutrophication and other environmental process. Hypophosphite (HP) originating from manmade and natural sources was evidenced as present in the environment and was investigated rarely. Recently, iron oxide has been used as a catalyst for oxidising organic contaminants with hydrogen peroxide (i.e. heterogeneous Fenton-like reaction). This study focused mainly on the oxidation of 1.0 mM HP by hydrogen peroxide in the presence of a novel iron oxide catalyst (B1 catalyst) which was prepared through a fluidised-bed Fenton reactor (FBR-Fenton). The background experiments including the oxidation experiment of HP by air only, by H2O2 only and adsorption of HP by B1 catalyst were first elucidated. It was found that HP could not be oxidised at all by air and H2O2 at pH 2.5-12 in 24 hours. On the other hand, it could be adsorbed by B1 catalyst with 89.8% removal at pH 2.5 in 5 hours and complete desorption at pH 11.0. Then, we investigated the effects of pH and Fe leaching from the catalyst on the oxidative efficiency of HP. We found that although the removal rate of HP at pH 2.5 is faster than that at pH 4.0, B1 catalyst has a higher HP oxidation efficiency at pH 4.0 than that at pH 2.5. We conclude that it is a major heterogeneous catalytic oxidation by our novel iron oxide catalyst to oxidise HP at pH 4.0. Also, B1 could be a useful and potential catalyst for the treatment of HP wastewater.     

膨润土负载纳米零价铁去除水中铅的研究

将纳米零价铁通过液态还原法负载于膨润土上,目的是为了比较负载对提高纳米零价铁去除重金属铅的能力的影响。从负载后扫描电镜图像中可以看出,负载后的纳米零价铁分散度更好。在相同投加量下,负载了纳米零价铁的膨润土对重金属铅的去除能力要远高于膨润土和纳米零价铁。铅的起始浓度为200mg／L,膨润土＋纳米零价铁的复合材料在0．4g／L的投加量下,去除率就达到90％以上。对材料的动力学研究结果则表明：纳米零价铁的反应速度较快,大部分的铅的去除都在1h以内完成。将吸附动力学实验结果进行一级和二级动力学反应拟合。二级拟和的线性相关系数明显高于一级。说明纳米零价铁和膨润土＋纳米零价铁复合材料与铅的反应更符合二级动力学反应假设。另外,纳米零价铁对铅的去除受到起始浓度的影响较大,而膨润土＋纳米零价铁则基本不受起始浓度的影响。     

Batch and column tests for the development of an immobilization technology for toxic heavy metals in contaminated soils of closed mines

Laboratory tests of various chemical treatments for the immobilization of copper, nickel, and lead in soils typically found at mine facilities were evaluated. A series of balch, adsorption tests, and lab-scale continuous column tests were conducted to optimize the design parameters for the full-scale immobilization processes. The laboratory test program consisted of batch and column experiments to measure the leachability and subsequent immobilization of the single heavy metal, Cu²⁺+, Pb²⁺+, and Ni²⁺+ in an artificial soil which was composed of bentonite and quartz fine sand. Batch equilibrium methods were used to test the ability of a large number of chemical additives to react with heavy metals in contaminated soil. The two best treatment chemicals (CaO and Na₂S) for each soil-metal combination were selected for more detailed columns studies. The column tests were carried out in the acidic pH range. According to the results of the column leaching test, it was found that the degree of heavy metal leaching is highly dependent on pH. An adsorption test was performed under acidic conditions (pH 4) to evaluate bentonite as an additive to treat acid mine drainage (AMD).