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1.
酸性膨润土处理含重金属废水初探   总被引:20,自引:0,他引:20  
比较了膨润土及酸性膨润土处理重金属离子的性能;着重探讨了酸性膨润土去除废水中铅、镉、镍、铜、铬、锌的适宜条件;将它用于电镀废水中重金属离子的处理,效果较好。  相似文献   

2.
pH对电解处理垃圾渗滤液的影响   总被引:2,自引:0,他引:2  
在不同的pH值条件下对氯离子和重金属离子含量不同的渗滤液和邻硝基苯酚人工模拟废水进行了电解处理,着重考察了不同pH值条件下氯离子浓度和重金属离子种类对有机物电解去除效果的影响。结果表明,电解处理过程中, pH值对有机物电解去除效果的影响与渗滤液的水质有关,尤其与渗滤液中氯离子和重金属离子浓度以及重金属离子种类有关。在pH=2的条件下电解处理氯离子和重金属离子含量均很低的渗滤液,有利于有机物的氧化去除;在pH=9的条件下电解处理氯离子和重金属离子浓度均较高的渗滤液,其COD的电解去除效果最好;在pH=2或pH=12的条件下电解处理氯离子浓度高而重金属离子浓度低的渗滤液,能促进有机物的氧化分解。在一定浓度范围内,渗滤液中无机变价离子的组成不同,电解处理垃圾渗滤液的最佳pH值也不同。  相似文献   

3.
以丙烯酸,四乙烯五胺,二硫化碳和氢氧化钠为原料合成了一种二硫代氨基甲酸盐类高分子重金属螯合剂,PATD,采用红外光谱对其结构进行了表征。研究了PATD的投加量、体系pH对Cu2+和Ni2+模拟废水的处理效果的影响。结果表明,PATD高分子重金属螯合剂处理浓度为50 mg/L的Cu2+和Ni2+模拟重金属废水时,当PATD/重金属离子质量比分别大于6(Cu2+)和12(Ni2+)时,处理后废水中残留的重金属离子浓度均低于国家污水综合排放一级标准。PATD在较宽p H范围内均可有效去除重金属Cu2+和Ni2+离子;对Cu2+的去除效果要好于Ni2+。对低浓度(1.0 mg/L)的Cu2+和Ni2+废水的处理同样具有很好的效果。  相似文献   

4.
微电解-生物法处理含铬电镀废水的研究   总被引:10,自引:0,他引:10  
采用微电解-生物法组合工艺处理含铬电镀废水,在实验过程中,电镀废水中的重金属离子通过微电解法预处理可去除90%以上,剩余部分被后续工艺的微生物功能菌去除。实验结果表明:对Cr^6 含量为50mg/L,Cu^2 含量为15mg/L,Ni^2 含量为10mg/L的废水,经处理后,重金属离子的净化率达99.9%,且无二次污染。  相似文献   

5.
一种多DTC基团重金属螯合剂的合成及处理含铜废水性能   总被引:1,自引:1,他引:0  
合成了一种新的二硫代氨基甲酸盐类重金属螯合剂CDTC,并对其处理游离铜离子、EDTA络合铜和柠檬酸络合铜废水的性能进行了研究.实验结果表明:CDTC能直接去除已络合的铜,对不同形态的Cu2+去除率均达99%以上,处理后的废水中Cu2+剩余浓度达到我国<污水综合排放标准>(GB 8978-1996)一级标准;在废水pH=...  相似文献   

6.
选矿废水的回用处理研究与实践   总被引:10,自引:0,他引:10  
铅锌矿泡沫浮选废水含有大量Pb^2 离子和有机硫化物,经过混凝沉淀和活性炭吸附,去除其中的悬浮物,重金属离子和部分COD,降低其起泡性,燃后回用生产。回用实践证明,选矿废水经过上述工艺处理后,其浮选选别指标与洁净水基本一致。  相似文献   

7.
固定化微生物技术及其在重金属废水处理中的应用   总被引:15,自引:0,他引:15  
固定化微生物技术是一种有效的废水生物处理技术。较为全面地介绍了其定义、分类及载体选择。全面系统地介绍了固定化微生物(主要是菌类和藻类)技术近年来在重金属废水处理中的应用现状,分析认为,固定化微生物技术对于处理含各种重金属离子的废水均有很广阔的应用前景,并对今后的研究方向做了探讨。  相似文献   

8.
一种重金属螯合剂的制备及其性能   总被引:1,自引:0,他引:1  
采用聚丙烯酰胺和磺胺在碱性条件下合成了一种新型的重金属螯合剂—PAS,并对合成原料PAM和产物PAS进行了红外光谱和紫外光谱表征,分析结果表明,PAS中有N—C—S和C-S生成。将PAS用于重金属离子的螯合实验,研究了温度、pH和初始浓度对PAS去除镍离子性能的影响,用PAS处理100 mg/L的Cu2+、Zn2+、Cd2+和Pb2+的单个离子模拟废水,去除率最高分别可达到90%、96%、99%和99%。用PAS处理含Pb2+、Cd2+、Zn2+和Cu2+混合废水,去除顺序为Pb2+〉Cd2+〉Zn2+〉Cu2+。PAS对重金属离子具有很好的螯合效果,应用前景广阔。  相似文献   

9.
介绍了一个采用螯合沉淀法处理电镀废水的典型工业实例。在工业装置上,进行了氢氧化钠、硫化钠和DT-CR去除重金属离子效果的对比,讨论了DTCR的加入量与处理成本的关系和pH值对DTCR用量的影响。结果表明,将废水的pH值调至8.0~8.5后再加DTCR,可以使DTCR的使用量最少,处理成本最低;此法对重金属离子的去除效果远优于传统化学沉淀法。  相似文献   

10.
螯合沉淀法处理电镀废水的工业实践   总被引:2,自引:0,他引:2  
介绍了一个采用螯合沉淀法处理电镀废水的典型工业实例.在工业装置上,进行了氢氧化钠、硫化钠和DT-CR去除重金属离子效果的对比,讨论了DTCR的加入量与处理成本的关系和pH值对DTCR用量的影响.结果表明,将废水的pH值调至8.0~8.5后再加DTCR,可以使DTCR的使用量最少,处理成本最低;此法对重金属离子的去除效果远优于传统化学沉淀法.  相似文献   

11.
R.D. Rhue  K.D. Pennell  P.S.C. Rao  W.H. Reve 《Chemosphere》1989,18(9-10):1971-1986
Competitive adsorption of ethylbenzene (EB) and water on bentonite and of p-xylene (pXYL) and water on kaolin and silica gel was studied using a technique that allowed the amount of adsorbed water and alkylbenzene to be measured independently. EB adsorption on bentonite was not affected by water at relative humidities (RH) near 0.23 but was reduced significantly at RH's near 0.50. pXYL adsorption on kaolin and silica gel decreased with increasing RH, especially above a RH of about 0.2. Increasing RH not only decreased the amount of alkylbenzene adsorption but also resulted in a change from Type-II adsorption isotherms to ones that were essentially linear. Linear isotherms for the adsorption of hydrophobic organic compounds on hydrated soil have generally been attributed to partitioning into organic carbon (OC). However, since the clays and oxide used here had very low to trace amounts of OC, it is suggested that processes involving only mineral surfaces can give rise to linear isotherms. Based on solubility considerations alone, partitioning of EB and pXYL into adsorbed water films was not considered to be an important adsorption mechanism in this study. The effect of cation hydration on the amount of water adsorbed from a mixture of water and pXYL vapors was evaluated by comparing adsorption on Li- and Na-saturated kaolin.  相似文献   

12.
纳米有机膨润土对苯酚的吸附性能研究   总被引:3,自引:1,他引:2  
通过对天然膨润土改性,制备纳米有机膨润土并用于吸附苯酚,探讨了吸附时间、溶液pH、纳米有机膨润土投加量等因素对苯酚吸附的影响。结果表明,吸附在5 min内快速达到平衡,溶液pH可以影响苯酚在溶液中的状态,是影响苯酚吸附性能的重要因素。纳米有机膨润土吸附苯酚的过程可用伪二级反应动力学方程来描述,伪二级吸附速率常数为1.3 g/(mg.min)。吸附等温线符合Langmuir等温方程,在25℃时,Langmuir理论最大吸附容量可达到536.32 mg/g,吸附热力学参数表明吸附过程是自发的、放热的物理吸附过程。  相似文献   

13.
Summary

Adsorption of chlorfenvinphos and methidathion from dissolutions on H+, Ca++, Na+ and K+ are studied. In all cases the saturating cation distinctly influenced the Freundlich‐type adsorption, with adsorption decreasing in the following sequence: H+> Ca++> Na+ > K+. Chlorfenvinphos adsorption was slightly greater than methidathion in two clays, and the adsorption extent for them in kaolinite is slower that bentonite.  相似文献   

14.
皂土对CuCl2的吸附性能   总被引:1,自引:0,他引:1  
研究了CuCl2在荷结构负电荷皂土上的吸附性能,考察了pH、无机以及有机添加剂等因素的影响,并结合IR和XRD实验结果探讨了吸附机理。研究表明,皂土对CuCl2有很强的吸附能力,其吸附动力学和吸附等温线分别符合准二级速率方程和Langmuir方程。初始pH增大,吸附量增加。无机以及有机添加剂均能能明显抑制吸附。Cu2+在皂土上的吸附层在微观上可分为因化学键合作用而形成的内络合层和因静电作用而形成的外络合层。  相似文献   

15.
研究了CuCl2在荷结构负电荷皂土上的吸附性能,考察了pH、无机以及有机添加剂等因素的影响,并结合IR和XRD实验结果探讨了吸附机理。研究表明,皂土对CuCl2有很强的吸附能力,其吸附动力学和吸附等温线分别符合准二级速率方程和Langmuir方程。初始pH增大,吸附量增加。无机以及有机添加剂均能能明显抑制吸附。Cu2+在皂土上的吸附层在微观上可分为因化学键合作用而形成的内络合层和因静电作用而形成的外络合层。  相似文献   

16.
商丹红  包敏 《环境工程学报》2014,8(5):1982-1986
采用铁盐改性制得铁基膨润土,研究了其对水中磷酸根的吸附性能及影响因素,结果表明,通过对膨润土的改性提高了磷的去除率,含磷废水初始pH值的大小对磷的去除率影响不大,初始浓度越低越有利于磷的去除。磷的去除率随改性膨润土的投加量增大而提高,随温度升高而增大。进一步研究表明,改性膨润土对磷的吸附是吸热反应,其吸附等温线可采用Langmuir等温吸附方程拟合;改性膨润土对磷的吸附是快速吸附,在20 min内,磷去除率达70%以上,符合准二级吸附动力学模型。  相似文献   

17.
Adsorption of phenol by bentonite   总被引:51,自引:0,他引:51  
The potential of bentonite for phenol adsorption from aqueous solutions was studied. Batch kinetics and isotherm studies were carried out to evaluate the effect of contact time, initial concentration, pH, presence of solvent, and the desorption characteristics of bentonite. The adsorption of phenol increases with increasing initial phenol concentration and decreases with increasing the solution pH value. The adsorption process was significantly influenced by the solvent type in which phenol was dissolved. The affinity of phenol to bentonite in the presence of cyclohexane was greater than that in water and was lowest in the presence of methanol. Methanol was used to extract phenol from bentonite. The degree of extraction was dependent on the amount of phenol adsorbed by bentonite. X-ray diffraction analysis showed that the crystalline structure of bentonite was destroyed when cyclohexane was used. The ability of bentonite to adsorb phenol from cyclohexane decreased as the water to cyclohexane ratio was increased. Furthermore, hysteresis was observed in phenol desorption from bentonite in aqueous solutions. The equilibrium data in aqueous solutions was well represented by the Langmuir and Freundlich isotherm models. The removal of phenol from aqueous solutions was observed without surface modification.  相似文献   

18.
Bentonite was modified by quaternary ammonium cations viz. cetytrimethylammonium (CTA), cetylpyridinium (CP), rioctylmethylammonium (TOM) and pcholine (PTC) at 100% cation exchange capacity of bentonite and was characterized by X-ray diffraction, CHNS elemental analyser and Fourier transform infrared spectroscopy. The sorption of imidacloprid on organobentonites/bentonite was studied by batch method. Normal bentonite could adsorb imidacloprid only upto 19.31–22.18% while all organobentonites except PTC bentonite (PTCB), enhanced its adsorption by three to four times. Highest adsorption was observed in case of TOM bentonite (TOMB) (76.94–83.16%). Adsorption kinetic data were fitted to pseudo-first-order, pseudo-second-order and intraparticle diffusion models. For normal bentonite data were best fitted to pseudo-first-order kinetic, while for organobentonites fitted to pseudo-second-order kinetics. Sorption data were analysed using Freundlich, Langmuir, Temkin and Dubinin–Radushkevich isotherm models. Data were well fitted to Freundlich adsorption isotherm. Product of Freundlich adsorption constant and heterogeneity parameter (Kf.1/n) was in following order: TOMB (301.87) > CTA bentonite (CTAB) (152.12) > CP bentonite (CPB) (92.58) > bentonite (27.25). Desorption study confirmed hysteresis and concentration dependence. The present study showed that the organobentonite could be a good sorbent for removal of imidacloprid from natural water sample also. Percentage adsorption and Distribution coefficient (mL g?1) value of different adsorbent was in following order: TOMB (74.85% and 297.54) > CTAB (55.78% and 126.15) > CPB (45.81% and 84.55) > bentonite (10.65% and 11.92).  相似文献   

19.
巯基化改性膨润土对重金属的吸附性能   总被引:2,自引:0,他引:2  
以钙基膨润土为基本材料,制备了巯基化改性膨润土,并对比研究了此材料与其他17种改性膨润土和原材料对重金属的吸附性能.结果表明,巯基化膨润土对镉的吸附能力显著优于其他材料,在本实验条件下,其对镉的吸附率高于其他材料30%以上,对镉的吸附量可达52.1 mg/g.巯基化膨润土对铅的吸附能力在重金属竞争吸附条件下优于其他材料,而其对镍的吸附能力在所有材料中处于中等水平;另外,巯基化膨润土对3种重金属的吸附受重金属竞争吸附影响较小.因此,在所研究的材料中,巯基化膨润土材料是一种最理想的重金属吸附材料.  相似文献   

20.
T Viraraghavan  K Slough 《Chemosphere》1999,39(9):1487-1496
Batch kinetic and isotherm studies were carried out to determine the adsorptive characteristics of peat and bentonite mixtures for pentachlorophenol, and to examine the hydraulic conductivity of peat-bentonite mixtures to determine if they are applicable for use as cutoff barriers. Batch kinetic studies showed that over 90% of PCP was removed from water spiked with approximately 1 mg/l of PCP using a peat-bentonite (5%) mixture. The equilibrium time was 8 hours. The optimum pH range for adsorption of PCP by the peat-bentonite mixture was found to be 3-3.5. Batch isotherm studies showed that the adsorption of PCP by the peat-bentonite mixture from aqueous solution was best described by the Freundlich isotherm equation. Batch adsorption studies using various ratios of bentonite in the mixture showed that the adsorption of PCP decreased linearly with increased amount of bentonite in the mixture, indicating that adsorption of PCP by the peat moss portion of the mixture was the dominant process. The inverse of the hydraulic conductivity was found to increase exponentially with an increase in the bentonite content of the mixture over the range studied. The minimum hydraulic conductivity observed was 3.3 x 10(-7) cm/s for a 50% peat-50% bentonite mixture. Peat-bentonite mixtures can be used to successfully remove PCP from aqueous media and can be used effectively as a barrier to attenuate the migration of PCP through soil and groundwater systems.  相似文献   

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