改性花生壳和木屑对水中活性艳红的吸附研究

用经过磷酸改性的花生壳和木屑制成混合吸附剂对水中活性艳红K-2BP进行吸附研究,通过静态试验系统地考察了混合吸附剂中改性花生壳和木屑的质量比、混合吸附剂的投加量、p H、温度和振荡速率等重要因素对K-2BP吸附效果的影响,并对吸附机理进行了探讨。研究结果表明:改性花生壳和木屑对10 mg/L K-2BP吸附的最佳条件为:改性花生壳和木屑的质量比1∶3.5,混合吸附剂的投加量0.9 g,温度328 K,p H值14,振荡速率120r/min,水中K-2BP的去除率可达98.6%,影响因素中p H值的影响最大。Langmuir吸附模型和伪二级动力学模型能较好地描述混合吸附剂对水中K-2BP的吸附过程,理论的最大吸附量为10.83 mg/g,吸附过程为吸热反应,可自发进行,因此改性花生壳和木屑吸附K-2BP技术在实际污染处理中具有良好的应用前景。     

磷酸改性板蓝根药渣污泥基生物炭的制备及其对含铅废水的处理研究

铅[Pb(Ⅱ)]对水资源的污染越来越严重,寻找高效、低成本的吸附剂一直是一个难题。选用污泥和板蓝根药渣这两种固体废物使用共热解的方式制备了生物炭,为了增强对废水中铅离子的吸附,用磷酸(H₃PO₄)对生物炭进行了改性处理。通过SEM图像可以看出改性生物炭的孔隙结构变得更加发达,比表面积增大。EDS谱图的结果表明改性生物炭在废水中吸附Pb(Ⅱ)的过程可能存在阳离子交换作用。FTIR、XRD和XPS图像分析显示改性生物炭在废水中吸附Pb(Ⅱ)的过程可能存在络合作用和共沉淀作用。吸附动力学试验结果显示,拟一级动力学模型,拟二级动力学模型和Elovich模型的R²均大于0.99,表明物理和化学吸附在改性生物炭去除Pb(Ⅱ)的过程中都起着重要作用。吸附等温线分析表明,吸附容量n大于1,证实改性生物炭对Pb(Ⅱ)具有良好的吸附效果。由此可见,对环境友好的磷酸改性板蓝根药渣污泥基生物炭可以作为一种有效的吸附剂从水系统中去除Pb(Ⅱ)。     

改性陶土颗粒吸附砷的实验研究

以赤玉土为骨料烧制陶土材料,经FeCl3溶液浸渍及热处理改性后制备成新型的改性陶土颗粒吸附剂,对其表面特征及除砷性能进行初步研究:BET测定得出该吸附剂比表面积为36.493m2/g,孔容量为0.070mL/g;SEM EDX显示吸附剂表面有大量铁、氧元素分布;对比该吸附剂和HCl溶液改性吸附剂表面的微观数码照片及3D影像图,表明该吸附剂表面存在大量铁氧化物;该吸附剂在中性pH范围内有良好吸附除砷能力,共存的氟离子、磷酸根离子对除砷效果有不同程度的竞争影响,碳酸根离子对除砷效果无显著影响;Freundlich等温线方程能较好地拟合As(V)的吸附过程(R2=0.9927),吸附平衡时的饱和吸附容量可达43.491mg/g。低成本高效的改性陶土颗粒应用于实际的砷吸附处理,具有较好的应用前景。     

载镧改性凹凸棒土对水中As(Ⅲ)的吸附特性

为提高凹凸棒对水中As(Ⅲ)的吸附能力,以七水合氯化镧、凹凸棒土(ATP)为原料,通过浸渍法制得载镧改性凹凸棒土。通过响应面优化试验,探究了最佳改性条件,并进行了改性材料对水中As(Ⅲ)的等温热力学和吸附动力学试验。结果表明:改性时氯化镧的最佳浓度为0.6 mol/L,吸附剂最佳投加量为0.3 g,最佳反应pH值为6;通过响应面优化试验,得到最佳改性条件为:氯化镧浓度为0.61 mol/L、pH值为6.8和吸附剂投加量为0.38 g,此时载镧改性凹凸棒土对As(Ⅲ)的吸附量为166 μg/g;吸附等温线符合Freundlich方程模型,吸附过程为自发且吸热过程,准二级模型能更准确地描述其吸附动力学过程,表明该吸附过程中化学吸附起主要作用。     

提取樟油后的樟叶残渣制作重金属离子吸附剂

以提取樟油后的樟叶废弃物为原料,通过功能化处理制备生物质重金属离子吸附剂,分析了樟叶吸附剂的粒径、改性方法、用量、废水初始浓度和离子强度等因素对其Pb(II)吸附性能的影响。结果表明,樟叶吸附剂的粒径越小,吸附能力越强;经过BTCA功能化后的BTCA-CL樟叶吸附剂对Pb(II)的吸附能力最强;随着初始溶液浓度增加,樟叶吸附剂对Pb(II)吸附量逐渐提升;吸附剂用量的增加和水溶液中存在的盐离子使得其对Pb(II)吸附有所降低,其吸附机理以分子链上活性功能团与重金属离子间络合配位的化学吸附为主。樟叶吸附剂作为廉价的吸附材料,在去除废水重金属离子上具有较大的应用价值。     

改性玉米芯吸附水中重金属离子的实验研究

以玉米芯做原料,用酒石酸改性,利用改性玉米芯吸附水中的Cu2＋ 和Pb2＋实验结果表明,实验中改性玉米芯吸附水中的Cu2＋ 和Pb2＋的吸附条件为：pH为5,吸附时间为120min,初始浓度为50mg／L,投加量为0．5g,在此条件下,改性玉米芯对Cu2＋ 和Pb2＋的吸附去除率分别为68％和94％,普通玉米芯对Cu2＋和 Pb2＋的吸附去除率分别为25％和65％。吸附过程更加能够符合准二级动力学方程,吸附规律能够更好地用Freundlieh方程所描述。改性玉米芯对重金属离子有选择吸附的能力,Pb2＋更加容易被吸附。本实验对于重金属的去除具有一定的参考价值。     

花生壳对模拟废水中Cr(Ⅵ)的动态吸附特性研究

采用废弃花生壳对质量浓度为20 mg/L的Cr(Ⅵ)模拟水样进行动态吸附实验研究。结果表明:在室温条件下,用粒径为1.6～2.5 mm花生壳作吸附剂,用量为5.0 g,介质pH值为1.0,流量为3 mL/min,吸附后水样中Cr(Ⅵ)的去除率可以达到99.08%,Cr(Ⅵ)质量浓度为0.184 mg/L,满足GB 8978—1996《污水综合排放标准》的标准。对模型的拟合结果表明,Thomas模型能较好地反映吸附过程特征,花生壳饱和吸附容量为9.4 mg/g。从动态吸附穿透曲线中可见,219 min时达到吸附穿透点,1312 min时达到吸附衰竭点。     

降雨径流中玉米芯营养素淋出及吸附特性

为评估玉米芯作为生物滞留设施中填料土添加剂的可行性,通过理化性质测试、摇床淋出试验、等温吸附试验,与现有添加剂柳木屑、陶粒、稻壳生物炭进行对比,研究玉米芯的理化性质和营养素的淋出及吸附特性。结果表明：玉米芯轻质多孔,具有较大的比表面积和阳离子交换量,其氮磷含量低,有丰富的含氧官能团;以玉米芯作为添加剂,在去离子水的淋洗作用下,氮磷营养素淋出量低、淋出速度快,在降雨径流中氮磷营养素淋出量降低,淋出速度减缓;在营养素质量浓度为2 mg/L的典型降雨径流中,玉米芯可吸附25 mg/kg的NH⁺₄和79 mg/kg的PO■,相较于其他材料,玉米芯吸附效果突出。玉米芯可作为填料土添加剂用于生物滞留设施中,施用玉米芯可降低填料土营养素淋出风险,提升生物滞留设施对降雨径流中污染物的吸附和去除效果。     

盐酸改性浒苔对Cr(Ⅵ)的吸附性能研究

为利用浒苔处理含Cr(Ⅵ)废水,对浒苔进行了盐酸改性,通过间歇吸附试验研究了pH值、盐酸改性浒苔投加量、吸附时间及温度对盐酸改性浒苔吸附Cr(Ⅵ)的影响。结果表明:使用盐酸改性浒苔作为吸附剂去除废水中Cr(Ⅵ)的方法是可行的,酸性条件有利于Cr(Ⅵ)的吸附,当pH值为1、Cr(Ⅵ)初始质量浓度为100 mg/L时,去除率可达99.7%;准二级动力学方程能更好地拟合试验数据,颗粒内扩散阻力比外部传质阻力的影响更显著;吸附等温线数据更符合Langmuir模型,吸附吉布斯自由能为负值,而吸附焓变为正值,盐酸改性浒苔吸附剂对Cr(Ⅵ)的吸附是自发的吸热过程。     

农村生活污水处理中SBR工艺效能研究

随着污水的排放标准越来越严苛，传统序批式反应器(SBR)的污水处理效能有待提升，以便满足污染物的排放要求。鉴于此，选择废弃玉米芯制备生物炭投加至SBR系统内，考察其对该工艺污染物去除效能和污泥沉降速率的影响，探讨其应用于强化SBR工艺污水处理效能的可行性。研究结果表明：(1)玉米芯生物炭具有优良的表面结构，为其吸附污染物和附着微生物提供了条件；(2)玉米芯生物炭的投加能有效缩短SBR系统的启动耗时，同时增强对污水中COD、NH₄⁺-N、TN、TP的去除效能；(3)投加玉米芯生物炭的SBR系统具有更高的污泥沉降速率，有利于泥水分离和污水处理效果的进一步提升。研究结果可为SBR工艺改良和废弃资源在污水处理中的再利用提供技术参考。     

农业废弃物作为吸附剂去除水中重金属研究

农业废弃物主要由纤维素和木质素组成,是一种潜在的重金属吸附剂。文中归纳了几种农业废弃物吸附剂及其改性方法,阐述了改性农业废弃物吸附重金属的机理,讨论了pH、重金属离子初始浓度、吸附剂用量、反应温度等因素对改性农业废弃物吸附能力的影响,并展望了改性农业废弃物的应用前景。     

吸附法去除地下水铁锰的研究进展

为了解决地下水铁、锰含量过高的问题,在众多研究方法中,吸附法由于具有容量大、耗能少、污染小、去除快和可循环等优点,被广泛应用于地下水除铁除锰中。重点介绍了锰砂、沸石、火山岩、生物质、活性炭和硅碳素等吸附剂的吸附原理与吸附效果,阐述了一部分吸附剂的改性效果与影响因素。指出了各种吸附剂未来的改进方法和研究方向锰砂可以通过改性来弱化pH值等影响因素对它的吸附影响,沸石和火山岩的研究重心可继续放在改性上,重点研究污染区域的生物质的吸附效果,研究硅碳素与其他吸附剂联合吸附的效果。     

Modification of granular activated carbon using low molecular weight polymer for enhanced removal of Cu(2+) from aqueous solution.

Palm shell activated carbon was modified via surface impregnation with polyethyleneimine (PEI) to enhance removal of Cu(2+) from aqueous solution in this study. The effect of PEI modification on batch adsorption of Cu(2+) as well as the equilibrium behavior of adsorption of metal ions on activated carbon were investigated. PEI modification clearly increased the Cu(2+) adsorption capacities by 68% and 75.86% for initial solution pH of 3 and 5 respectively. The adsorption data of Cu(2+) on both virgin and PEI-modified AC for both initial solution pH of 3 and 5 fitted the Langmuir and Redlich-Peterson isotherms considerably better than the Freundlich isotherm.     

活性炭吸附技术与树脂吸附技术处理DIBP废水的对比

采用活性炭吸附技术和树脂吸附技术进行增塑剂DIBP生产废水处理对比试验。结果表明:NDA-66树脂对邻苯二甲酸的吸附效果最好,去除率达93.9%,其次为椰壳活性炭,对增塑剂DIBP生产废水中COD和邻苯二甲酸的去除率分别为57.3%和83%,煤质和果壳活性炭的废水处理效果较差,对COD和邻苯二甲酸的去除率均在20%左右,且活性炭吸附不具有选择性,无法对邻苯二甲酸进行回收,不能产生相应的经济效益。而采用NDA-66树脂吸附处理增塑剂DIBP生产废水,其污染物削减量是活性炭吸附的4~5倍,回收邻苯二甲酸可产生110.8万元/a的经济效益,同时树脂脱附再生容易,可重复利用2年左右,因而具有更大的推广应用价值。     

Comparative MCDM Analysis for AMD Treatment Method Selection

Robule Lake, located in Eastern Serbia, near the city of Bor, is being influenced by waste materials from mining activities. For the purification of water from Robule Lake, contaminated with various metal ions (Fe, Cu, Zn, Mn, Cd, Ni, etc.), acid mine drainage (AMD) treatment methods such as: passive treatment method, sequential neutralization, ion exchange, adsorption process based on low cost adsorbents, adsorption process based on natural zeolits, electrodialysis, filtration with nanofiltration membranes, and reverse osmosis, were evaluated by the following MCDM methods: TOPSIS, VIKOR, MOOSRA, WASPAS, and CoCoSo. Criteria used for the evaluation were: efficiency in the metal ions removal and the quality of the purified water, necessity of pre-treatment and / or post-treatment of treated water, possibility of using the generated waste, capital costs, operating and maintenance costs, needed area, and sensitivity of the method. The results of the MCDM analysis showed that sequential neutralization was the most appropriate method for this wastewater, while passive treatment system and ion exchange were ranked as second and third, respectively.

After the selection of AMD treatment method, neutralization tests with lime were carried out with the water sample from Robule Lake. The results of sequential neutralization testing showed that concentration of Fe ions could be lowered to 1 mg/L at pH 4. The values of Cu, Zn, and Ni ions concentration obtained at pH 7 were 0.04, 0.65, and 0.21 mg/L, respectively, while the values of Mn and Cd ions concentration of 0.01 and 0.0001 mg/L, were obtained at pH 10.

     

Phosphonated cross-linked polyethylenimine for selective removal of uranium ions from aqueous solutions

Among many remediation techniques for metal ion removal, polymeric adsorbents are efficient and widely applied. This has made them comparable with other remediation techniques in terms of technical and economic efficiency, feasibility as well as green technology. This study was dedicated to the development of an insoluble modified chelating polymer for use as an adsorbent for abstraction of uranium from wastewaters. Cross-linked polyethylenimine (CPEI) was phosphonated by phosphorous acid for selective removal of uranium ions. The binding affinity of the phosphonated cross-linked polyethylenimine (PCPEI) to uranium ions was assessed as well as its ability to be regenerated for reuse. It exhibited high removal percentage for uranium ions up to 99% with high selectivity even in the presence of competing ions (Mn, Ni, As). The Freundlich isotherm was found to be the best fit describing the adsorption process of uranyl ions onto the PCPEI. The pseudo-second-order equation was found to better explain the adsorption kinetics, implying chemisorption. The thermodynamic study of the adsorption revealed high activation energies which confirmed the chemisorption as the mechanism of adsorption.     

Evaluation of the adsorption capacity of alkali-treated waste materials for the adsorption of sulphamethoxazole

The present work is to develop potential adsorbents from waste material and employ them for the removal of a hazardous antibacterial, sulphamethoxazole, from the wastewater by the Adsorption technique. The Adsorption technique was used to impound the dangerous antibiotics from wastewater using Deoiled Soya (DOS), an agricultural waste, and Water Hyacinth (WH), a prolific colonizer. The adsorption capacity of these adsorbents was further enhanced by treating them with sodium hydroxide solution and it was seen that the adsorption capacity increases by 10 to 25%. Hence a comparative account of the adsorption studies of all the four adsorbents, i.e. DOS, Alkali-treated DOS, WH and Alkali-treated Water Hyacinth has been discussed in this paper. Different isotherms like Freundlich, Langmuir and Dubinin-Radushkevich were also deduced from the adsorption data. Isotherm studies were in turn used in estimating the thermodynamic parameters. DOS showed sorption capacity of 0.0007 mol g(-1) while Alkali-treated Deoiled Soya exhibited 0.0011 mol g(-1) of sorption capacity, which reveals that the adsorption is higher in case of alkali-treated adsorbent. The mean sorption energy (E) was obtained between 9 and 12 kJ mol, which shows that the reaction proceeds by ion exchange reaction. Kinetic study reveals that the reaction follows pseudo-second-order rate equation. Moreover, mass transfer studies performed for the ongoing processes show that the mass transfer coefficient obtained for alkali-treated moieties was higher than the parent moieties. The breakthrough curves plotted from the column studies show percentage saturation of 90-98%. About 87-97% of sulphamethoxazole was recovered from column by desorption.     

华南地区典型土壤渗透性的改良配置研究

为改善我国华南地区土壤黏性大、渗透性差的问题,研究华南地区土壤与落地灰、砾石、沸石、海砂、草根和枯树叶等多种材料的改良配置,测试不同重量配比下试验土壤的渗透性,获取不同有机、无机材料对典型土壤自然入渗能力的改善效果(包括各种材料的单独作用和择优性混合作用效果)。结果表明:单材料试验中,低重量配比的草根和枯树叶试验土壤的峰值入渗速率分别为0.178 mL/s和0.163 mL/s,且有机材料的改良效果优于无机材料。高重量配比的5～9 mm砾石和5～9 mm落地灰试验土壤分别在重量配比为40%和60%情况下,峰值入渗速率达0.338 mL/s和0.717 mL/s,在同重量配比的所有材料里具有最佳入渗效果。多材料混合试验中,枯树叶、5～9 mm砾石和5～9 mm落地灰相结合的试验土壤实现最佳入渗效果。研究成果为改善华南地区土壤渗透性能提供科学依据。