海藻酸钠凝胶海绵体的制备及其对Pb2+和Cu2+的吸附

以海藻酸钠与钙离子交联形成凝胶,采用真空冷冻干燥技术将凝胶制备成超轻海绵体,考察其对Pb2+和Cu2+的吸附作用.结果表明,在溶解过程,天然多糖海藻酸钠微观结构首先由丝状结构逐渐向片层结构伸展,而海藻酸钠凝胶海绵体则形成了致密的多孔结构,微观结构发生变化.当海藻酸钠与氯化钙交联比(质量比)是1:5时,所得的凝胶海绵体的比表面积达到2.1543 m2/g.在pH=3,吸附时间50 min,海绵体质量浓度为0.5 g/L,吸附温度40℃的优化条件下,该海绵体对Cu2+和Pb2+的吸附量分别达到29.4和88.9 mg/g.重复使用5次后,海绵体对Cu2+和Pb2+的吸附量分别为18.7和77.1 mg/g.吸附动力学拟合结果表明,海绵体对Cu2+和Pb2+的吸附以化学吸附为主.     

玻璃轻石吸附亚甲基蓝的研究

主要研究了玻璃轻石对水中亚甲基蓝的吸附性能,研究了吸附平衡时间、酸碱度(pH值)、玻璃轻石的用量、水相中亚甲基蓝的起始浓度等因素对吸附能力的影响.实验结果显示,吸附在60 min内可达到吸附平衡,吸附过程的动力学方程用准二级动力学模型能更好地进行线形拟合,当水体中pH>2时吸附效果最好.水样中亚甲基蓝的起始浓度减少,亚甲基蓝的吸附率略有上升,吸附过程能用弗罗因德利希(Freundlich)吸附等温方程描述.     

木屑生物炭的制备及其对Pb2+的吸附特性研究

以松木（SM）和楠木（NM）木屑为原料,分别在300、450、600℃下制备了6种木屑生物炭,通过扫描电镜、孔径与比表面积分析仪、傅里叶红外光谱仪和热重分析仪对生物炭的理化性质进行了表征,并探讨了金属离子（Na⁺、K⁺、Ca²⁺）和pH值对生物炭吸附Pb²⁺的影响,同时研究了其吸附动力学。研究结果表明：在相同制备条件下,随着热解温度升高,生物炭的比表面积和孔容积增大,其最可几孔径呈下降趋势,楠木生物炭的比表面积（23.2~311.4 m²/g）均大于松木生物炭（17.6~210.6 m²/g）;FT-IR分析表明,热解温度的升高使生物炭芳香化程度增强,有助于生物炭与Pb²⁺形成稳定的结构。楠木生物炭对Pb²⁺吸附量（46.92~77.12 mg/g）高于松木生物炭（34.90~62.79 mg/g）;溶液中的Na⁺和K⁺不利于生物炭对Pb²⁺的吸附,Ca²⁺有利于Pb²⁺的去除。生物炭对Pb²⁺的吸附均符合准二级动力学方程,颗粒内扩散模型分析表明吸附受多种因素共同影响。     

高岭石-MBT复合材料的制备及其对Pb2+的吸附性能

采用不同的方法制备了高岭石 - 2 -巯基苯并噻唑 (简写为高岭石 -MBT)复合体 ,并考察了其对水溶液中Pb2 的吸附性能 ,得到了高岭石 -MBT复合体吸附水溶液中Pb2 离子的最佳工艺条件 ,测得其对Pb2 的最大吸附量为 4.2 5 μmol/g。     

大孔螯合树脂对Pb2+的吸附行为及机理

通过静态和动态吸附实验,研究了Pb2+在D418树脂上的吸附行为,从热力学和动力学方面对吸附过程进行了分析,并通过红外光谱探讨了吸附机理. 结果表明,在所研究的条件范围内,Pb2+在D418树脂上的吸附是吸热过程,同时符合Freundlich和Langmuir等温吸附方程;液膜扩散为Pb2+在D418树脂上吸附速率的主要控制步骤,随着溶液初始浓度的增大,吸附速率逐渐减小;313 K温度下树脂的静态饱和吸附容量为375 mg/g,在298 K下用3 mol/L的硝酸作为解吸剂,解吸率可达97%;最佳的解吸剂用量为5倍床层体积. 该树脂吸附操作简单,易再生,不产生二次污染,有望用于含铅废水的治理及铅的富集.     

KMnO4改性汉麻废弃物对水体中Pb2+吸附工艺优化研究

建立了汉麻废弃物KMnO_4改性方法及其对水体中Pb~(2+)吸附工艺优化方案,以汉麻废弃物为切入点,通过KMnO_4预处理,制备成表面富含Mn—O基团吸附剂,达到吸附Pb~(2+)净化水体的目的。通过单因素分析确立3因素3水平正交试验方案,确定了改性汉麻废弃物对水体中Pb~(2+)吸附最佳工艺:溶液pH 4.5、吸附时间20 min、改性汉麻废弃物吸附剂投放量与Pb~(2+)离子浓度比值(A/C)25条件下,改性汉麻废弃物吸附容量最大为40.25 mg/g。KMnO_4改性汉麻废弃物Pb~(2+)吸附剂具有易制备、环保、高效等优点。     

农业废弃物吸附重金属的研究进展

农业废弃物是一种来源广泛、经济且环保的天然吸附剂,尤其对废水中的重金属离子有着很强的吸附能力。综述了几种农业废弃物和改性后农业废弃物吸附废水中重金属离子的研究进展以及影响因素,指出了该方法应用中存在的主要问题,提出了未来的发展方向。     

改性铁尾矿对废水中Pb2+的吸附及机理研究

以铁尾矿为主要原料,采用酸碱改性法制备了一种新型吸附材料,研究了其对吸附废水中Pb2+的影响,并对其的理化性质和吸附机理进行表征.结果 表明,在pH为5.0、初始Pb2+的质量浓度200 mg/L、吸附剂投加量1.00 g/L、温度25℃、吸附时间为12h条件下,改性铁尾矿对Pb2+的去除率为95.02％.Langmi...     

农林废弃物生物吸附剂处理重金属废水的研究进展

介绍了重金属废水的来源与危害、传统的处理方法以及常见的农林废弃物,并阐述了吸附机理。农林废弃物用于处理重金属废水实现了资源的综合利用,具有广阔的工业前景。农林废弃物是数量巨大的农业和林业的副产品,具有可再生和再生周期短等特点,且能交联产生活性基团,并且能快速、高效地去除水中的金属离子,因此,利用农林废弃物制备生物吸附剂吸附水中的重金属备受关注。     

三种农业废弃物对废水中Pb^2＋吸附性能的比较

通过吸附实验比较了花生壳、甘蔗渣、玉米芯三种农业废弃物对废水中Pb^2＋的吸附性能。在初始Pb^2＋浓度为30mg·L^-1、吸附时间为1h、溶液pH值为5的条件下,三种材料对Pb抖均有较好的吸附性能,尤其以花生壳的吸附性能最佳。在模拟水样中,花生壳的吸附性能相对较稳定。三种吸附材料经过一次再生后仍具有一定的吸附性能,具有较好的实用价值。     

改性玉米芯的制备及其对Pb~(2+)吸附性能研究

在N,N-二甲基甲酰胺中,以次磷酸钠为催化剂,采用柠檬酸对氢氧化钠处理过的玉米芯进行化学改性,制备得到生物吸附剂,并研究其对Pb~(2+)的吸附性能。通过探讨投加量、吸附时间、Pb~(2+)溶液的不同吸附温度、pH等因素研究改性玉米芯对废水Pb~(2+)吸附性能的影响。结果表明,改性的玉米芯投加质量为0.5 g、pH为7、Pb~(2+)初始质量浓度为100 mg/L时,吸附性能较好,吸附平衡时间t为120 min,最大吸附率为88.10%、最大吸附量为35.24 mg/g。可以用准二级动力学方程和Langmuir方程描述改性玉米芯的吸附过程。     

Study on Efficient Adsorption Mechanism of Pb2+ by Magnetic Coconut Biochar

Lead ion (Pb²⁺) in wastewater cannot be biodegraded and destroyed. It can easily be enriched in living organisms, which causes serious harm to the environment and human health. Among the existing treatment technologies, adsorption is a green and efficient way to treat heavy metal contamination. Novel KMnO₄-treated magnetic biochar (KFBC) was successfully synthesized by the addition of Fe(NO₃)₃ and KMnO₄ treatment during carbonization following Pb²⁺ adsorption. SEM-EDS, XPS, and ICP-OES were used to evaluate the KFBC and magnetic biochar (FBC) on the surface morphology, surface chemistry characteristics, surface functional groups, and Pb²⁺ adsorption behavior. The effects of pH on the Pb²⁺ solution, initial concentration of Pb²⁺, adsorption time, and influencing ions on the adsorption amount of Pb²⁺ were examined, and the adsorption mechanisms of FBC and KFBC on Pb²⁺ were investigated. The results showed that pH had a strong influence on the adsorption of KFBC and the optimum adsorption pH was 5. The saturation adsorption capacity fitted by the model was 170.668 mg/g. The successful loading of manganese oxides and the enhanced oxygen functional groups, as evidenced by XPS and FTIR data, improved KFBC for heavy metal adsorption. Mineral precipitation, functional group complexation, and π-electron interactions were the primary adsorption processes.     

改性纤维素微球的制备及其对Pb2＋吸附性能的研究

利用绿色环保的碱／尿素／水溶剂体系直接制备纤维素溶液共混聚乙烯亚胺（PEI）,然后通过高压静电法制备再生纤维素微球,并与戊二醛交联固定化,制备了复合型吸附材料。借助吸附动力学和吸附等温方程研究了改性纤维素微球对Pb2＋的吸附性能,结果表明改性纤维素微球对Pb2＋具有较好的吸附容量达到9．46mg／g,相比空白微球提高50％以上,并且吸附过程符合准二级动力学方程和Freundlich等温方程。     

改性硅藻土对Pb(Ⅱ)的吸附作用

采用云南腾冲硅藻土 ,将其进行化学改性 ,系统研究了改性硅藻土对水溶液中Pb2 + 的吸附作用。讨论了吸附剂用量、溶液pH值、作用时间等条件对吸附性能的影响 ,结果表明 :改性硅藻土对Pb2 + 的吸附作用明显优于原土 ,且吸附符合Freundlich方程。吸附后溶液残留Pb2 + 质量浓度为 0 .74mg·L- 1 ,达国家一级排放标准     

磁性沸石的制备与表征及其对Pb2+的吸附性能

通过氨基甲酸乙酯的粘结作用使天然沸石与Fe3O4结合,制备了具有吸附和磁性能的沸石复合体. 利用XRD, SEM, 氮吸附等温线和振动样品磁强计等对所制磁性沸石进行了表征. 结果表明,与钠型沸石相比,磁性沸石的结构没有发生明显改变,比表面积由25.13 m2/g增至38.01 m2/g. 磁性沸石和钠型沸石对模拟废水中Pb2+的平衡吸附量分别为54.53和66.99 mg/g,两者对Pb2+的吸附符合Langmuir型液相吸附,其单层饱和吸附量分别为50.89和65.92 mg/g.     

Adsorption of Pb2+ on blast furnace sludge

An evaluation of the applicability of blast furnace sludge, generated during the purification of blast furnace gases, as an adsorbent to remove heavy metals from industrial effluents is presented. The influence of residence time and temperature on the adsorption efficiency of the sludge is studied for the particular case of Pb²⁺. The adsorption data, which fit the Langmuir equation well, show that the blast furnace sludge has a high adsorption capability, up to 80 mg Pb per g dried sludge at saturation. The order of magnitude of the adsorption enthalpy, calculated from the apparent equilibrium constant, indicates that the adsorption of Pb²⁺ on the sludge is of a physical nature. XPS and EDAX analysis suggest that the physical adsorption process partially occurs through ionic exchange between Pb²⁺ and other ions such as Ca²⁺. Techniques exist for the recovery of metallic iron and either metallic lead or lead oxide from the sludge. The rendering of sludge into pellets, followed by their controlled heating, allows not only the extraction of these metals, but also makes use of the coke within the sludge. These techniques are clearly interesting alternatives to the dumping of this toxic and hazardous waste.     

Adsorption properties of Pb2+ on thermal-activated serpentine

ABSTRACT

Adsorption properties of nature and thermal-activated serpentines to Pb²⁺ in aqueous solution were investigated. The results showed that Freundlich isotherm and pseudo-second-order kinetics model were suitable to describe the adsorption process of Pb²⁺ on serpentines. The thermodynamic parameters indicated that the adsorption process was endothermic and spontaneous. The serpentine activated at 700°C exhibited maximum adsorption capacity to Pb²⁺. Based on the XRD and XPS characterization, it could be found that the structure of serpentine did not change significantly during the adsorption process, and Pb²⁺ was adsorbed on the serpentine surface as the precipitation of Pb(OH)Cl and Pb(OH)₂.