磺酸基改性磁性吸附剂去除水中的Cu(Ⅱ)

利用水热法制备出Fe_3O_4磁性粒子,通过正硅酸乙酯水解使Fe_3O_4外面包覆SiO_2(Fe_3O_4@SiO_2),最后利用3-氨丙基三甲氧基硅烷和氯磺酸进行改性,合成了磺酸基改性磁性吸附剂.采用FT-IR、BET和XRD等方法对合成吸附剂进行表征,并探讨接触时间、初始浓度、溶液pH值等因素对吸附性能的影响.表征结果显示,成功合成了磺酸基改性磁性Fe_3O_4@SiO_2粒子;Fe_3O_4@SO_3Na比表面积为20.4587 m~(-2)·g~(-1).吸附实验结果显示,在25℃条件下,Fe_3O_4@SO_3Na对Cu~(2+)的吸附等温线符合Freundlich吸附等温方程,实验条件下最大吸附量为16.13 mg·g~(-1).Fe_3O_4@SO_3Na吸附Cu~(2+)可在1 h内达到吸附平衡且吸附动力学遵循拟二级动力学模型.溶液中存在盐离子时,发现盐离子的存在对吸附效果几乎没有影响;溶液中含有柠檬酸时对吸附效果产生抑制.吸附剂经3次循环使用后仍有吸附性能,表明吸附剂具有良好的再生性和经济性.     

磁性金属有机骨架Fe3O4@ZIF-8的制备及对偶氮染料刚果红的高效吸附

采用常温搅拌法,在聚苯乙烯磺酸钠(PSS)处理过的Fe_3O_4表面诱导生长ZIF-8壳层,成功合成了磁性核壳金属有机骨架Fe_3O_4@ZIF-8,并对其吸附去除偶氮染料刚果红的性能进行了探究,考察了刚果红初始浓度和接触时间、Fe_3O_4@ZIF-8投加量以及pH对刚果红去除的影响。SEM、TEM、XRD、FT-IR及VSM表征结果证明,ZIF-8纳米颗粒已成功负载于Fe_3O_4表面,形成了典型的核壳结构,并且具有优异的磁学性能。吸附实验结果表明,反应最佳pH为6,吸附剂投加量为500 mg·L~(-1);当反应时间达到180 min时,吸附达到平衡。吸附反应的吸附动力学和吸附等温线分析表明,刚果红染料在Fe_3O_4@ZIF-8上的吸附动力学符合二级动力学方程,吸附等温线符合Langmuir模型。Fe_3O_4@ZIF-8吸附剂对刚果红具有高效的选择吸附性能并且在循环吸附中展现出良好的循环吸附性能。因此,磁性核壳金属有机骨架Fe_3O_4@ZIF-8作为吸附剂在去除刚果红染料方面有着广阔的应用前景。     

硫化锰纳米颗粒高效去除重金属镉

中国镉污染问题日益严峻,开发高效的镉吸附剂,是解决环境镉污染问题的重要技术手段。采用共沉淀方法合成了硫化锰纳米颗粒,研究了其对重金属镉的吸附行为,并采用X射线衍射(XRD)、扫描电镜(SEM)、高分辨透射电镜(HR-TEM)、比表面积(BET)等技术手段探究了硫化锰纳米颗粒的形貌、化学组分以及镉的去除机制。结果表明,MnS纳米颗粒呈球状,平均粒径100 nm,比表面积30.56 m~2·g~(-1)。MnS纳米颗粒对Cd~(2+)的吸附动力学数据较好地符合伪二级动力学模型;吸附等温线数据较好地符合Langmuir模型,说明MnS对Cd2+的吸附是以化学吸附为主的单分子层吸附。使用Langmuir拟合的MnS饱和最大镉吸附量为349.6 mg·g~(-1),在众多镉吸附材料中处于前列。对于模拟工厂重金属废水的处理,MnS纳米颗粒可以在5 h内使镉的浓度由60 mg·L~(-1)降至国家规定排放线以下(0.1 mg·L~(-1)),且吸附过程中水体pH稳定,对水体干扰小。在多种重金属离子共存的情况下,仍可以达到接近100%的Cd~(2+)去除率。硫化锰相对稳定,在空气中放置30 d仍有80%的镉去除率。较高的离子交换量形成CdS沉淀是MnS高效去除镉的主要原因。     

再生条件对钾基CO_2吸附剂吸附性能的影响

通过固定床实验研究了再生条件对钾基CO2吸附剂吸附性能的影响。深入分析了再生温度和气氛对吸附穿透时间和饱和吸附量的影响。研究发现,当再生温度为200℃,N2气氛下再生时效果最佳,在此条件下再生后钾基CO2吸附剂循环性能良好,10次循环后仍然能有很好的吸附效果;再生气氛中有H2O或CO2时会影响再生反应的进行,不利于吸附剂的再生。     

基于吸附质-分子探针的新型交联壳聚糖的吸附特性

研究了CCTS对低浓度游离酸的吸附特性,基于吸附质-分子探针电位法,考察了吸附剂活性中心数目、游离酸种类和温度对吸附行为的影响。结果表明,在30℃时,CCTS吸附游离酸的过程,遵循单分子层机理进行吸附。吸附剂―吸附质相互作用能U制约表观吸附速率常数K,K、U大小分别为2.519×10-2,4.084×10-2,9.398×10-2L/min和7.264,7.420,7.926 kJ/mol,两者存在线性相关性,呈逐渐增大趋势。K、U大小随着活性中心数目G的增加而增大。CCTS吸附游离酸为吸热过程,吸附表观活化能Ea为33.98 kJ/mol。3种类型游离酸K、U的大小顺序为:HClO4>HNO3>H2SO4,吸附分维数Dw分别为1.384、1.567、1.911,Dw值越大,导致表观吸附速率常数降低。     

蔗渣吸附剂的制备及其对氨氮的吸附研究

从炭化蔗渣的炭化温度和用量,吸附动力学、吸附温度,溶液的酸度、组成,吸附等温线及氨氮的存在形式等方面探讨了实验制备的炭化蔗渣吸附去除溶液中氨氮的影响因素。结果表明,直接炭化法蔗渣吸附剂制备的最佳炭化温度为400℃;在初始氨氮浓度一定的条件下,随着吸附剂投加量的增大,炭化蔗渣对氨氮的吸附量减少;炭化蔗渣吸附氨氮的动力学曲线符合准二级动力学模型,吸附常数K2=3.59g(/mg/min);当pH=9.20时炭化蔗渣对氨氮的最大吸附量为10g/kg;在实验的pH范围内,pH=10时炭化蔗渣对氨氮的吸附去除最好;直接炭化法蔗渣吸附剂对氨氮吸附去除的最佳温度是40℃;pH为3.98～9.20时吸附等温线可用Langmuir与Freundlich吸附等温方程进行拟合。     

吸附法处理重金属废水研究进展

对吸附法处理重金属废水的研究进展进行了综述,包括吸附机理、影响吸附的相关因素和常用吸附剂及其应用,同时展望了吸附法处理重金属废水的发展方向。     

玉米秸秆制备活性炭吸附剂新工艺

以玉米秸秆为原料,采用化学活化法制备活性炭吸附剂,研究了料液比、添加剂用量、活化剂的浓度、活化时间、活化温度等工艺条件,探讨了浸泡时间和超声活化对产品收率和吸附性能的影响。结果表明:较佳的工艺条件为料液比1∶2.5、活化剂浓度60%、添加剂用量6%、活化时间45 min、活化温度400℃。超声浸泡可以大大缩短浸泡时间,明显提高产品的收率和吸附性能。制备出的吸附剂吸附性能优于商业活性炭,产品质量指标接近水质净化用活性炭标准。     

A novel aminated polymeric adsorbent for removing refractory dissolved organic matter from landfill leachate treatment plant

Refractory dissolved organic matter (DOM) from landfill leachate treatment plant was with high dissolved organic carbon (DOC) content. An aminated polymeric adsorbent NDA-8 with tertiary amino groups and sufficient mesopore was synthesized, which exhibited high adsorption capacity to the DOM (raw water after coagulation). Resin NDA-8 performed better in the uptake of the DOM than resin DAX-8 and A100. Electrostatic attraction was considered as the decisive interaction between the adsorbent and adsorbate. Special attention was paid to the correlation between porous structure and adsorption capacity. The mesopore of NDA-8 played a crucial role during uptake of the DOM. In general, resin in chloride form performed a higher removal rate of DOC. According to the column adsorption test, total adsorption capacity of NDA-8 was calculated to 52.28 mg DOC/mL wet resin. 0.2 mol/L sodium hydroxide solution could regenerate the adsorbent efficiently.     

Heavy metal removal from aqueous solution using carbonaceous K2S-impregnated adsorbent

A novel carbonaceous adsorbent for heavy metal removal was prepared from raw coal by one-step simple sulfur impregnation using K2S. Raw coal was mixed with K2S powder and then heated at 800°C for 30 min in nitrogen to produce K2S char. The sulfur content and form in K2S char were determined, and the ability of K2S char to adsorb Zn2+, Cd2+ and Pb2+ was examined. The K2S impregnation was e ective at impregnating sulfur into coal, especially in the form of elemental, thiophenic and sulfatic sulfur. The sulfur content of K2S char was higher than those of raw coal and pyrolysis char. The Zn2+ removal in 2.4 mmol/L of Zn2+ solution by K2S char was higher than raw coal with the removal rate of 100%. K2S char adsorbed Pb2+ and Cd2+ in 24 mmol/L of Pb2+ and Cd2+ solution with the removal rate of 97% and 35%, respectively. The elution extents of adsorbed Pb2+ and Cd2+ were zero in distilled water and 27% in 0.1 mol/L HCl solution. These results indicated that an e ective adsorbent for heavy metal ions was prepared from coal using K2S sulfur impregnation, and that the adsorbed metals were strongly retained in K2S char.