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采用铁盐共沉淀连续式泡沫分离法脱除废水中的铬(Ⅲ)离子,实验考察了pH值、Fe2+/Cr(Ⅵ)摩尔比、十二烷基苯磺酸钠(SDBS)浓度、空气流量、分离时间等因素的影响.结果表明,最佳分离工艺条件为,Fe2+/Cr(Ⅵ)摩尔比5∶1,pH值9.0,空气流量450 mL/min,SDBS浓度60 mg/L,分离时间30 m... 相似文献
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为考察连续泡沫分离法采收微藻细胞的可行性 ,在一种斜臂泡沫分离装置上 ,以螺旋藻为模型藻种 ,较为详细地研究了载气流率、藻液进料流率、浓度、pH值、离子强度、乙醇浓度、进料位置、泡沫段与液相段高度之比等因素对泡载采收性能的影响。结果表明 :在载气流率、藻液进料流率或藻液浓度较低时采收性能良好 ;当 pH值为 11、离子强度为 1 3× 10 4 μs·cm-1、乙醇浓度为 3%(体积 )时泡载收率可达 2 5 %~ 45 %;采用泡沫相段进料有利于提高泡载采收性能。提出的连续泡载采收动力学模型与实验值拟合较好 . 相似文献
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泡沫分离法处理含Cr(Ⅲ)废水的实验 总被引:8,自引:0,他引:8
采用间歇式泡沫分离法分离废水中的铬离子。实验考察了各种操作条件对含Cr(Ⅲ )废水进行泡沫分离过程的影响 ,包括 :废水的pH值 ,表面活性剂的加入量以及气体流量等 ,确定了较佳的操作条件。实验结果也表明泡沫分离技术对含铬离子废水的除Cr 有较好的分离效果 相似文献
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本报告叙述了泡沫上浮分离法去除铜、锌和三价铬的试验研究。中试流程主要是 pH 调节-投加混凝剂-三级混合凝聚-投加表面活性剂-泡沫上浮分离-泡沫破坏-澄清。试验是采用人工配制水进行的;表面活性剂采用十二烷基磺酸钠(NLS)。 相似文献
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对纳米TiO2去除水中铬离子进行了研究,并对反应条件对金属离子脱除率的影响进行了系统的讨论。研究结果表明,对于铬离子体系,pH值越小,其光催化效果越显著。此外,EDTA的添加有助于有效地去除铬离子。 相似文献
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采用负载Rh的泡沫独石整体型催化剂研究了甲烷催化部分氧化过程,考察了外界温度、空速和甲烷与氧气进料比例对反应转化率和选择性的影响,并对过程控制条件和调控参数进行了分析。研究结果表明该过程为毫秒级超短接触过程,反应可以在自热条件下进行,高空速条件下(8×105 h-1),甲烷与氧气进料比(体积比)为1.8,甲烷转过率超过90%,CO选择性接近95%,H2选择性超过90%。外界加热对过程有利,可获得更高的转化率和选择性。 相似文献
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主要研究了活性炭表面负载不同的金属离子对其吸附苯并噻吩的影响.通过浸渍法分别将6种不同的过渡金属离子负载在活性炭表面上,用静态吸附法测定了苯并噻吩硫化物在改性活性炭上的吸附等温线,应用软硬酸碱理论分析和讨论了其吸附能力的差异.结果表明,活性炭表面负载Ag+、Ni2+、Cu2+或Zn2+离子,可提高活性炭吸附苯并噻吩硫化物的能力,而活性炭表面负载Fe3+或Co3+离子,反而降低了活性炭吸附苯并噻吩硫化物的能力,这主要是活性炭表面的酸碱性质发生变化.采用密度泛函数理论法计算结果表明,苯并噻吩的电负性χ为2.638,属软碱类物质;由于Ag+为软酸,活性炭负载Ag+离子,增加了其局部表面的软酸,从而增强了对苯并噻吩硫化物的吸附;由于Ni2+、Cu2+和Zn2+离子属交界酸,负载Ni2+、Cu2+、Zn2+离子增加了活性炭表面的交界酸,也在一定程度上提高了其表面对苯并噻吩硫化物的吸附;当活性炭表面负载了硬酸性Fe3+或Co3+离子,其局部表面硬酸增大从而降低了其对苯并噻吩的吸附. 相似文献
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Membrane separation and foam separation are widely used separation techniques.To make use of their advantages,membrane separation and foam separation were integrated to dispose waste water with low concentration of linear alkylbenzene sulfonate(LAS).A method of forcing bubbles through a single hollow fiber ultrafiltration tube was put forward to study the separation efficiency of the integrated process.The effects of pressure,gas-liquid ratio and LAS concentration on the separation efficiency were investigated.Under the conditions of pressure 0.03—0.1 MPa,gas-liquid ratio 0—0.9,and LAS concentration 0—70 mg·L-1,the membrane permeate flux was raised from 26.5 to 38.6 L·m-2·h-1,increased by 48.6%,and the retention rate was raised from 37.0% to 64.9%,increased by 75.5%.The results show that the integrated process can reduce the concentration polarization and membrane fouling.Moreover,this method reduces the back-mixing of foam separation and increases the concentration of bulk liquid phase for foam separation.Therefore,the integrated separation promotes mass transfer and improves separation efficiency. 相似文献
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对淀粉(St)接枝共聚丙烯酰胺(AM)并与巯基乙酸(MCAA)反应进行了研究,将得到的产物用于低浓度含镉废水处理取得了较好的效果。研究了淀粉与丙烯酰胺配比不同对St-AM接枝率和接枝效率的影响并对巯基化后得到的产物St-AM-MCAA的巯基含量进行了测定。对低浓度(0.4mg/L)含镉废水的处理研究发现:含镉废水在pH=8,添加量为50mg时镉去除率可达89.7%;St-AM-MCAA较St-AM产物能提高Cd2+去除率10%以上。 相似文献
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《分离科学与技术》2012,47(6):868-876
A green chemical method was explored and described for separation and extraction of the toxic hexavalent chromium from aqueous solutions and real water samples. A green reduction reaction for the transformation of toxic hexavalent chromium into the nontoxic trivalent chromium ion was performed by using hydrogen peroxide. The produced Cr(III) was then extracted by biosorption on the surface of a novel and eco-friendly gelatin-grafted-baker’s yeast (Gelatin-Yeast) biosorbent. The investigated biosorbent was characterized by high capacity value of the reduced trivalent chromium species in pH 6.0 as 1.120 mmol g?1. The biosorption processes were examined, monitored, and optimized in different experimental and controlling parameters. The potential applications of Gelatin-Yeast for separation and removal of Cr(VI) from real industrial and sea water samples were also studied. 相似文献
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《分离科学与技术》2012,47(9):1421-1432
The present investigation was carried out to study the feasibility of foam separation for simultaneous removal of two types of inorganic hazardous contaminants, nickel(II) cations and chromium(VI) anions, from aqueous solutions and simulated wastewaters. The effects of pH of the solution, Ni/Cr ratio, collector and frother concentrations, induction and flotation time, and solution ionic strength on the co-removal efficiency of nickel(II) and chromium(VI) were studied. At the optimum conditions, removals more than 99.5% were obtained for nickel(II) and chromium(VI). The concerned contaminants were effectively removed when they coexisted at low as well as at high concentrations. Coflotation of nickel(II) and chromium(VI) from tap water and simulated electroplating wastewater resulted in removal percentages higher than 99.5% with residual concentrations below their permissible limits in potable water. High removal percentages, DFs, ERs, and VRs were achieved for their radionuclides, 63Ni(II) and 51Cr(VI), from simulated radioactive process wastewater. The results obtained in this study suggest the feasibility of the developed foam separation process for treatment, in a single-step, of wastewaters contaminated with cationic and anionic inorganic pollutants. 相似文献
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《分离科学与技术》2012,47(14):2183-2190
Hollow fiber supported liquid membrane (HFSLM) is a favorable method to extract both valuable compounds and heavy metal pollutants such as chromium, copper, and nickel at a very low concentration. In this work, the extraction of Cu(II) by LIX84I dissolved in kerosene was theoretically and experimentally investigated. A model to estimate the percentage of extraction of copper ions from synthetic water considering the effect of reaction flux in membrane phase of the HFSLM system was studied. H2SO4 solution was used as the stripping solution. The facilitated transport mechanism of the chemical reaction at the feed-membrane interface was taken into account in the model equations. The percentage of copper ion extraction was plotted against its initial concentration in feed and also feed flow rate. Subsequently, the separation time and separation cycle were determined in accordance with the simulated values of copper ion concentration and the feed flow rate from the model. The modeled results were in good agreement with the experimental data at the average percentage of deviation about 2%. 相似文献
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通过在电去离子(EDI)的淡化室和浓缩室中同时填充离子交换树脂而构成频繁倒极电去离子(EDIR)过程,用以解决处理含重金属离子溶液时EDI内部易产生金属氢氧化物结垢的关键难题。以NiSO4溶液为处理对象,采用浓缩水部分循环和浓、淡水流分步切换的运行工艺,利用EDIR单一过程,同步获得了淡化出水的高截留率和浓缩产品水的高浓缩倍数。实验条件下,倒极周期为4h可获最佳分离效果。对于含Ni2+50mg.L-1、pH为3.0的NiSO4溶液,EDIR的淡水出水和浓水出水的Ni2+浓度可分别达到1.5mg.L-1和3961mg.L-1,淡水中Ni2+的脱除率为97%,浓水的浓缩倍数则为79.2,接近理论值。实验范围内,EDIR过程运行稳定,未产生Ni(OH)结垢。 相似文献
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Chen HR Chen CC Reddy AS Chen CY Li WR Tseng MJ Liu HT Pan W Maity JP Atla SB 《International journal of molecular sciences》2011,12(11):8245-8258
The separation of mercury ions from artificially contaminated water by the foam fractionation process using a biosurfactant (surfactin) and chemical surfactants (SDS and Tween-80) was investigated in this study. Parameters such as surfactant and mercury concentration, pH, foam volume, and digestion time were varied and their effects on the efficiency of mercury removal were investigated. The recovery efficiency of mercury ions was highly sensitive to the concentration of the surfactant. The highest mercury ion recovery by surfactin was obtained using a surfactin concentration of 10 × CMC, while recovery using SDS required < 10 × CMC and Tween-80 >10 × CMC. However, the enrichment of mercury ions in the foam was superior with surfactin, the mercury enrichment value corresponding to the highest metal recovery (10.4%) by surfactin being 1.53. Dilute solutions (2-mg L(-1) Hg(2+)) resulted in better separation (36.4%), while concentrated solutions (100 mg L(-1)) enabled only a 2.3% recovery using surfactin. An increase in the digestion time of the metal solution with surfactin yielded better separation as compared with a freshly-prepared solution, and an increase in the airflow rate increased bubble production, resulting in higher metal recovery but low enrichment. Basic solutions yielded higher mercury separation as compared with acidic solutions due to the precipitation of surfactin under acidic conditions. 相似文献
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采用阴阳离子复合掺杂,以共沉淀法、超声共沉淀法、Pechini法和高温固相法合成掺杂锰酸锂前驱体,使用三段热处理方式,即650℃预烧、780℃烧结、550℃回火制备掺杂非化学计量尖晶石Li 1.05 Co 0.05 Ni 0.05 Mn 1.9 O 3.9 F 0.1 .通过化学容量分析测定Mn含量和平均价态,用粒度分布、电镜扫描(SEM)、X射线衍射(XRD)、电化学性能测试对产物进行表征.结果表明产物的Mn含量和平均价态与理论值吻合.比较各种合成方法,超声共沉淀法产物的粒径分布最窄、比表面积最小(0.96 m28226;g-1)、晶型完整、衍射强度最大、结晶性能最佳、晶格常数a为0.821 nm、晶粒尺寸L为57.78 nm.经装配电池电化学性能测定,超声共沉淀法产物的初始容量更高,循环性能更稳定,经30次循环后容量衰减仅9.3%. 相似文献