污泥制备活性炭对 Pb(Ⅱ)和Ni(Ⅱ)的吸附和回收利用

在静态条件下研究了用污泥制备的活性炭吸附剂去除水溶液中Pb(Ⅱ)、Ni(Ⅱ)的效果,考察了溶液pH值、吸附时间、吸附剂用量和Pb(Ⅱ)、Ni(Ⅱ)的初始浓度对去除率的影响.结果表明,污泥制备的活性炭吸附剂对Pb(Ⅱ)、Ni(Ⅱ)具有较强的吸附性能,pH值是影响吸附的主要因素;吸附过程符合Langmuir吸附等温式;在试验条件下,其对Pb(Ⅱ)具有更高的去除能力.还探讨了吸附Pb(Ⅱ)、Ni(Ⅱ)后回收铅和镍的可行性.     

活性炭负载Fe(Ⅲ)氧化物去除水中的磷酸根

利用活性炭负载铁氧化物制备了复合吸附剂,并用于水中磷酸根的去除.采用BET,SEM及XRD等手段对复合吸附剂的物理化学特性进行了表征,用静态吸附实验方法比较研究了复合吸附剂和活性炭从水溶液中吸附磷酸根的性质.结果表明:复合吸附剂具有快的吸附速度和高的吸附容量,其吸附磷酸根的性质受溶液pH值、铁含量及阴离子浓度的影响.在pH=3.0时,复合吸附剂对磷酸根的吸附容量为98.39 mg/g,而活性炭为78.90 mg/g.相比之下,Freundlich模型比Langmuir模型能更好地描述复合吸附剂和活性炭对磷酸根的吸附过程;而Lagergren二级方程却能很好地描述复合吸附剂对磷酸根的吸附动力学.水合氧化铁/活性炭复合吸附剂吸附磷酸根为吸热过程.     

无源应急密闭空间CO_2动态吸附性能研究

为了得到无源应急密闭空间中人员二氧化碳释放速率和不同吸附剂布置方式、气流组织方式及二氧化碳初始浓度时二氧化碳动态吸附性能,在密闭空气品质实验室中进行了人员生存实验和不同工况下的二氧化碳动态吸附实验。结果表明:人员二氧化碳释放速率小于相关文件规定的处理值,吸附剂布置方式对二氧化碳吸附效果影响明显,吸附剂平铺于纱网时吸附速率大于装入无纺布袋时,气流从吸附药板中穿过比从吸附剂表面流过出风量减少,吸附效率增大,二氧化碳初始浓度越高,吸附效果越好。     

城市污泥灰对电镀废水中Cu(Ⅱ)、Zn(Ⅱ)的吸附研究

通过分光光度法研究了城市污泥灰(MSSA)去除水溶液中铜(Ⅱ)、锌(Ⅱ)离子的情况,试验了MSSA对金属离子的去除效果,考察了起始pH值、吸附剂用量、金属离子浓度和吸附时间对铜(Ⅱ)、锌(Ⅱ)离子去除率的影响.结果表明,MSSA对铜(Ⅱ)、锌(Ⅱ)离子具有较强的吸附性能,吸附达到平衡时的接触时间为80 min,pH值为5.5～6.0,吸附剂最佳用量为15.0 g/L时,去除率在90%以上.静电吸附和离子交换是主要吸附形式.该吸附剂吸附性能优越,可有效地去除废水中相关金属离子.     

UiO-66/壳聚糖的制备及其对U(VI)的吸附机制

铀矿开采和冶炼等工艺产生大量低浓度铀废水,危害着生态环境和人类健康,从含铀废水中去除铀(VI)迫在眉睫。本文以UiO-66、壳聚糖(CS)为原料,采用交联法制备UiO-66/CS新型复合材料,通过静态吸附实验,考察不同pH值、吸附剂投加量、吸附时间及铀初始浓度等外部因素对U(VI)去除率的影响。通过SEM、FTIR、XPS等对UiO-66/CS材料进行表征分析,揭示吸附剂去除U(VI)的机制。结果表明：在铀初始浓度为5 mg/L,温度为298 K,p H为5,投加量为0.15 g/L,吸附时间120 min条件下,UiO-66/CS对U(VI)的去除率可达90.24%。吸附过程符合准二级动力学模型和Freundlich等温吸附模型。U(VI)吸附去除机制主要是-NH、-COOH、Zr-O、-OH等官能团与U(VI)发生络合作用。     

胺基接枝介孔材料MCM-41对低放废水的净化处理研究

将合成的胺基接枝改性的介孔材料MCM-41用于吸附处理模拟低放废水中低浓度的Mn2＋和Co2＋,研究吸附时间和pH值对吸附容量的影响,相比三种吸附等温线模型对实验数据的拟合性能,结果表明,该吸附剂对低浓度金属离子的吸附足Sips等温线模型。吸附剂对Mn2＋和Co2＋的最大吸附容量分别为0．377mmol／g和0．384mmol／g。竞争吸附实验表明,吸附剂对Co2＋结合能力要大于Mn2＋。固定填充床的动态吸附实验表明,动态条件下的吸附容量小于静态条件。     

腰果壳油基超交联聚合物的制备及吸附VOCs性能EI北大核心

以农业副产物腰果壳油为原料,通过外交联法和溶剂交联法分别制备超交联聚合物(HCPs)吸附剂F-HCP和C-HCP,并对其吸附挥发性有机化合物(VOCs)性能进行研究。采用红外光谱(FTIR)、热重分析(TGA)、N2吸-脱附法和扫描电子显微镜(SEM)等方法对制备的吸附剂进行表征,以静态吸附法考察两种超交联聚合物对六种VOCs的吸附性能,以邻二甲苯为典型VOC进行动态吸附,探讨进气浓度对吸附能力的影响。结果表明:相较于C-HCP,F-HCP显示出较高的静态吸附性能,其对邻二甲苯、甲苯、环己烷、正己烷、丁酮、丙酮的静态吸附量分别为930,801,300,214,203,164 mg·g^(-1);在进气浓度为2171 mg·m^(-3)时,F-HCP和C-HCP对邻二甲苯的动态吸附量分别为149 mg·g^(-1)和146 mg·g^(-1),平衡吸附量随进气浓度的增加而增大。循环再生吸附实验表明,C-HCP 5次循环吸附后的吸附量为首次吸附量的93.9%。     

Mg-Al-Ce水滑石吸附去除水中的硼

用共沉淀法成功制备了镁铝铈水滑石(Mg-Al-Ce-HT), 采用不同分析手段对材料进行表征。通过静态吸附实验研究了Mg-Al-Ce-HT的吸附效率与初始pH、吸附剂剂量、初始硼酸浓度和接触时间的关系。当pH小于8.0时, 溶液的pH对硼吸附几乎没有影响, 当pH超过8.0时, 吸附容量降低。吸附剂的最佳用量为200 mg, 最大吸附容量为32.52 mg·g ^-1。 硼去除量在160 min内达到平衡。吸附等温线表明吸附过程是一个非自发的吸热过程。吸附数据与Langmuir模型拟合良好, 表明吸附是单层吸附。     

Mg-Al-Ce水滑石吸附去除水中的硼（英文）

用共沉淀法成功制备了镁铝铈水滑石(Mg-Al-Ce-HT),采用不同分析手段对材料进行表征。通过静态吸附实验研究了Mg-Al-Ce-HT的吸附效率与初始pH、吸附剂剂量、初始硼酸浓度和接触时间的关系。当pH小于8.0时,溶液的pH对硼吸附几乎没有影响,当pH超过8.0时,吸附容量降低。吸附剂的最佳用量为200 mg,最大吸附容量为32.52mg·g–1。硼去除量在160min内达到平衡。吸附等温线表明吸附过程是一个非自发的吸热过程。吸附数据与Langmuir模型拟合良好,表明吸附是单层吸附。     

功能化介孔吸附剂的制备及其对银离子吸附性能的研究

以F127和CTMABr为模板剂,采用一步法经水热合成了巯基(-SH)修饰的新型介孔吸附剂,并将其应用于水溶液中Ag 的去除研究.分别考察了初始pH值、振荡时间、Ag 初始浓度和金属离子竞争对介孔吸附剂性能的影响.结果表明,在pH 5～6的范围内该吸附剂Ag 吸附量最大(Q=2.998mmool/g),其吸附机理是巯基(-SH)与Ag 的离子交换和配位化学吸附反应.在Cu2 、Ni2 、Co2 和pb2 等竞争性金属阳离子存在的情况下,Ag 去除率仍然高达90%以上.该介孔吸附剂对Ag 具有较高的吸附效率,其吸附符合Langmuir模型.     

Removal of organic compounds by alginate gel beads with entrapped activated carbon

The adsorption of alginate gel (AG) beads and AG with activated carbon entrapped (AG–AC) beads prepared using different types of metal ions were investigated by measuring the removal of several organic compounds with different charges and size. AG–AC beads prepared in a CaCl₂ solution adsorbed strongly positively charged compounds as well as electrically neutral and low molecular weight compounds such as p-chlorophenol. However, a high molecular weight humic acid was not adsorbed by AG–AC. The AG–AC selectively adsorbed p-chlorophenol from a humic acid solution. The adsorption capacity obtained from the adsorption isotherm of AC entrapped in AG was compared with that of AC. The AG–AC beads prepared in a solution of FeCl₃ were able to specifically adsorb negatively charged gallic acid. Thus, entrapping AC into AG resulted in the selective adsorption.     

Mg/Al水滑石对腐殖酸的去除性能研究

采用共沉淀法制备了 Mg/Al 水滑石,并在不同温度下煅烧。探究了煅烧温度、材料投加量、pH 值、腐殖酸初始浓度对水滑石去除腐殖酸的影响。结果表明,当金属物质的量比为3的 Mg/Al 水滑石投加量为0.5 g/L, pH 值为8.5,温度为25℃时,水滑石对10 mg/L 的腐殖酸的去除率能达到96.64%,此时,水滑石的饱和吸附量为19.33 mg/g。Mg/Al 水滑石经3次再生后,对腐殖酸的去除率仍然高达95%以上,表明 Mg/Al 水滑石的可重用性好。     

A comparative study of the adsorption of humic acid, fulvic acid and phenol onto Bacillus subtilis and activated sludge

The adsorption of humic acid and fulvic acid onto Bacillus subtilis cells and activated sludge biomass was studied as a function of pH and incubation time. The adsorption of humic and fulvic acids was strongly pH-dependent and followed the same trend on both surfaces, increasing in a sigmoidal way with decreasing pH over the 2-10 pH range. This behaviour is explained in terms of hydrophobic interactions between the uncharged biomass and the uncharged humic and fulvic acids. In contrast, the adsorption of phenol onto B. subtilis cells and activated sludge biomass showed in both cases an optimum pH at around 7.0. This optimum value may be interpreted in terms of a combination of hydrophobic interactions and hydrogen bonds between undissociated phenol and polar groups on the cell walls. Kinetic studies on the adsorption of humic acid, fulvic acid and phenol onto B. subtilis cells and sludge biomass pointed to a rapid uptake of the substances, with an equilibrium time of about 30 min. In all cases, the kinetic curves were acceptably fitted by non-linear regression to an exponential function, suggesting a first-order kinetic phenomenon. The specific adsorption values collected at optimum pH revealed that with the materials used in this work both B. subtilis and activated sludge follow the same adsorption trend: humic>fulvic>phenol. The lower adsorption of fulvic acid as compared with humic acid may be explained in terms of its lower hydrophobicity rather than its lower molecular size. On comparing the specific adsorption values of activated sludge versus B. subtilis, similar but lower figures were found for the three organic compounds studied. This similar behaviour suggests that both types of biomass base their adsorption capacity on the general characteristics of the bacterial cell wall, and the lower adsorption by the sludge would be due to a lower specific area due to clustering of the cells. This is remarkable, since sludge is a heterogeneous and cheap material in comparison with cultured bacterial cells.     

蒙脱土/Fe3O4/腐殖酸复合材料对U(Ⅵ)的作用机制

通过水热法制备蒙脱土/Fe₃O₄/腐殖酸复合材料(MFH),探究pH值、MFH的投加量、吸附时间、U(Ⅵ)初始浓度及温度等因素对MFH吸附U(Ⅵ)的影响。结果表明:在所选实验条件范围内,MFH的投加量对其吸附U(Ⅵ)的影响最大;当U(Ⅵ)初始浓度为5 mg·L^-1,pH值为6,MFH投加量为0.3 g·L^-1,温度为30℃时,MFH对U(Ⅵ)去除在30 min后达到平衡,此时去除率达到97.7%;MFH对U(Ⅵ)的吸附符合准二级动力学模型和Langmuir模型;MFH对U(Ⅵ)的去除机理为络合作用和还原作用。再生实验表明,经5次吸附-解吸后,MFH复合材料对U(Ⅵ)的吸附率仍在90%以上,表明MFH对U(Ⅵ)的去除效果较好且具有高效重复利用性。     

Simultaneous removal of metal ions and linear alkylbenzene sulfonate by combined electrochemical and photocatalytic process

Combined electrochemical removal of Zn(++) and Ni(++) and photo-oxidation of linear alkylbenzene sulfonate (LAS) by suspended TiO(2) particles was investigated. The effect of different process variables such as current density, pH and liquid flow rate on the sole electrochemical reduction of metal ions was also evaluated. At pH of 5.0, the removal of Zn(++) increased by 28% with increases in the liquid flux from 0.0021 to 0.0172m(3)m(-2)s(-1) while the removal of Ni(++) was only enhanced marginally. Under optimum operating conditions used in the present study (liquid flux=0.0172m(3)m(-2)s(-1), current density=0.166mAcm(-2), pH 5.0 and in the presence of LAS), Zn(++) and Ni(++) were reduced by 86 and 56%, respectively, over 7h of the sole electrochemical treatment. For the sole photocatalytic treatment of LAS at pH of 5.0, a 60% LAS degradation was obtained. However, the liquid flow rate did not have any considerable effect on the LAS oxidation. Finally, in the combined photocatalytic-electrolytic process, the LAS degradation increased to 76%. Nonetheless, in the combined system the Zn(++) and Ni(++) removal remained at comparable levels to those obtained in the sole electrochemical system.     

用腐植酸树脂分离富集-火焰原子吸收法测定电镀液中痕量铅

采用酚醛树脂对天然腐植酸交联固化,制备成腐植酸酚醛树脂.采用火焰原子吸收分光光度法(FAAS)研究了腐植酸酚醛树脂对铅的吸附性能.结果表明,腐植酸酚醛树脂对铅有较强的吸附能力,吸附量受介质pH值的影响,当pH值大于3.0时,铅可被定量吸附,最大吸附量可达17.28 mg/g.吸附于树脂上的铅可以用0.1 mol/L的HNO3溶液完全解脱.以FAAS法为检测手段,对镀铬液中痕量铅进行分离富集,建立了电镀液中痕量铅的测定新方法,应用于实际样品的测定,结果满意.     

Comparison of adsorption capacity of young brown coals and humic acids prepared from different coal mines in Anatolia

Binding of Zn2+ and Cd2+ cations to relatively young brown coals YBC (lignite), humic acids (HAs) and commercial humic acid (CHA) were studied in aqueous media at pH 2.7-6 by polarographic method. This study was conducted to evaluate the removal of heavy metals in an aquatic system without prior treatment. The general principles of cation binding to YBC and humic materials are discussed. Sorption of heavy metal ions (Zn2+ and Cd2+) on samples of YBCs from three areas (Ilgin, Beysehir, and Ermenek) in the vicinity of the city of Konya in Anatolia (Turkey) were compared with sorption of these metal ions on HAs, prepared from these YBCs. The ability of both types of sorbent to remove metals from aqueous solutions was studied as a function of pH and concentration of initial metal solutions. Sorption depends strongly on pH, the origin of the YBC and on the nature of the metal ion. Whereas, for YBCs the main ligand groups seem to be carboxylate ions, this is not the case for the HA polymers, prepared from three YBCs, which differ substantially from properties of commercial samples of "HA". The process is very efficient especially in the case of low concentrations of pollutants in water, where common methods are either economically unfavorable or technically complicated. Of the two metal ions examined, Cd2+ was found to form the most stable HA complexes, followed by Zn. Effective removal of metals was demonstrated at pH-values of 5-5.7. The adsorption isotherm was measured at 25 degrees C, using adsorptive solutions at the optimum pH-value to determine the adsorption capacity. An important aspect of the proposed method was that the removal was performed on several metals at a pH-range in which a given metal undergoes an adsorption process making the method useful for wastewater treatment.     

Role of humic acid entrapped calcium alginate beads in removal of heavy metals

Most of the available techniques for removal of heavy metals from solution such as leachates from waste sites are very expensive. The technique described in this paper is designed to study the removal of humic acid by alginate beads and the subsequent binding of the metals within the beads thus decreasing the leachability of heavy metals from a hazardous waste site. The entry of 500 mg/l humic acid into 3% calcium alginate beads in 24 h showed a distinct fluorescence as compared to the fluorescence shown by the entry of 100 and 250 mg/l of humic acid into alginate beads. Further, on treatment of calcium alginate beads containing 500 mg/l humic acid with metals such as Cu, Mn, Zn, Cr and Fe, quenching of fluorescence was noticed, which was maximum with Cu and minimum with Fe.     

褐煤腐植酸吸附铜的热力学机理

为了实现腐植酸在治理重金属污染方面的资源化应用,以褐煤中提取的腐植酸为吸附剂,研究了pH值对腐植酸吸附Cu~(2+)的影响,探讨了吸附的热力学特征和作用机理。结果表明:腐植酸对Cu~(2+)的吸附明显受pH值影响,吸附量随pH值的升高而增大,pH值约5时吸附率约为95%;吸附等温线符合R-P方程、Langmuir方程、Freundlich方程及D-R方程,与R-P方程和Langmuir方程的相关程度更高;吸附过程放热,随pH值升高吸附焓增大,吸附熵由正到负逐渐减小,吸附自由能小于零且呈减小趋势;不同pH值时吸附机理有明显的差别,pH值较低时吸附作用力主要为范德华力和氢键,pH=5时配位交换反应成为主要作用。