多氨基改性蔗渣对水溶液中Pb~(2+)、Zn~(2+)、Cd~(2+)、Cu~(2+)吸附性能的研究

蔗渣经多氨基改性处理后,得到多氨基改性蔗渣吸附剂。考察了多氨基改性蔗渣吸附剂对模拟废水中Pb2+、Zn2+、Cd2+、Cu2+的吸附性能,主要包括吸附时间、溶液pH值和温度对吸附量的影响以及吸附等温式的研究。研究表明,在实验范围内,Pb2+的吸附平衡时间为12h,适宜吸附Pb2+的pH值范围在4～5,Pb2+的最大吸附量为34.96mg/g;Zn2+的吸附平衡时间为20h,适宜吸附Zn2+的pH值在6.2左右,Zn2+的最大吸附容量为2.24mg/g;Cd2+的吸附平衡时间为20h,适宜吸附Cd2+的pH值在5.0左右,Cd2+的最大吸附容量为10.40mg/g;Cu2+的吸附平衡时间为20h;适宜吸附Cu2+的pH值在5.0左右;Cu2+在不同温度下的最大吸附容量为2.60mg/g。多氨基改性蔗渣对Pb2+、Zn2+、Cd2+、Cu2+的吸附均可用Freundlich方程和Langmuir方程描述。     

纤维素接枝共聚物对Cu2+和Ni2+吸附性能的研究

以己内酯为单体,在绿色溶剂离子液体中对纤维素进行接枝改性。研究了改性纤维素对金属离子Cu2+、Ni 2+的吸附性能,考察了金属溶液初始质量浓度和温度对吸附效果的影响,对比了改性纤维素对Cu2+和Ni 2+的吸附效果,同时对Cu2+的吸附热力学进行了研究。结果表明,在温度为298K,时间为2h时,改性纤维素对Cu2+、Ni 2+的吸附量分别为133mg/g、40.4mg/g;Cu2+初始质量浓度的增加及温度的降低有利于吸附的进行;改性纤维素对Cu2+的静态等温吸附符合Langmuir和Freundlich吸附等温式,吸附过程是放热过程。     

Pb2+离子印迹材料的制备及性能研究

以Pb2+作为模板,环氧氯丙烷作为交联剂,MWNTs-CO/PEI作为功能单体,制备Pb2+-IIP材料。采用红外光谱和TEM对产物进行了表征。探讨了初始浓度、溶液pH值、吸附剂质量对吸附容量的影响。通过静态吸附实验研究Pb2+-IIP和Pb2+-NIP材料吸附实验的影响因素。结果表明,当吸附溶液的pH=5.0,吸附剂质量为0.03g,Pb2+的初始质量浓度为45mg/L时,Pb2+-IIP的最大吸附量为37.50mg/g,是Pb2+-NIP的2.47倍,40min内即可达到吸附平衡,吸附速率较快,选择识别性好,重复使用率高。     

木质纤维素基纳米复合材料对Pb~(2+)、Cd~(2+)的吸附研究

以原位插层共聚法制备木质纤维素-g-丙烯酸/丙烯酰胺/蒙脱土(LNC-g-AA/AM/MMT)纳米复合材料,采用X射线衍射(XRD)、扫描电镜(SEM)对其结构进行表征。研究在金属离子初始浓度、吸附时间、吸附温度、pH值等不同吸附条件下,LNC-g-AA/AM/MMT纳米复合材料对Pb2+、Cd2+吸附性能的影响。结果表明,当Pb2+、Cd2+初始浓度分别为0.04和0.06mol/L,吸附时间分别为120和60min,吸附温度分别为40和30℃,pH值为5.5时,LNC-g-AA/AM/MMT纳米复合材料对Pb2+、Cd2+的吸附量分别高达504.2和246.9 mg/g。整个吸附过程均符合Langmuir吸附等温线模型和伪二级动力学模型,且是个自发放热的反应过程。同时对最佳条件下吸附饱和的LNC-g-AA/AM/MMT纳米复合材料进行解吸研究,脱附率分别为93.4%和92.9%。     

Cu~(2+)-IIP印迹材料的制备及性能研究

以Cu2+为模板,环氧氯丙烷(ECH)为交联剂,羧基碳纳米管(MWNTs-COOH)为载体,采用"Grafting onto"方法在羧基碳纳米管表面键连大分子链聚乙烯亚胺(PEI),制备了功能单体MWNTs-CO/PEI,获得铜离子印迹材料。利用FTIR、TEM对产物进行了表征,探讨了模板离子的初始浓度、溶液pH值、吸附时间对吸附容量的影响,以及印迹材料的吸附选择性和重复使用率。结果表明,PEI中的N-H键断裂,H原子被烷基取代,环氧氯丙烷发生开环反应,键连到PEI的N原子上;羧基碳纳米管表面包覆了一层厚度约为20nm的印迹层,呈蜂窝状;在Cu2+初始质量浓度为100mg/L、pH=6、吸附时间为1h时,Cu2+-IIP印迹材料和非印迹材料的最大吸附容量分别为43.68mg/g和21.85mg/g;在同时存在Cu2+、Zn2+的溶液中,印迹材料的选择性能较好;重复使用时,吸附性能稳定。     

改性玉米秸秆吸附Cu~(2+)的研究

研究了用磷酸改性的玉米秸秆吸附水溶液中Cu~(2+)的性能,考察了pH、温度、吸附时间、Cu~(2+)初始质量浓度和吸附剂用量对改性玉米秸秆吸附水溶液中Cu~(2+)性能的影响。结果表明:在实验条件下,改性玉米秸秆对Cu~(2+)的吸附率随改性玉米秸秆用量、吸附时间、溶液pH和温度增加而增大,随Cu~(2+)初始质量浓度的增大而降低,其对Cu~(2+)的吸附率可达78.3%。说明改性玉米秸秆对水溶液中Cu~(2+)具有良好的吸附能力。吸附过程的动力学模型拟合结果表明,改性玉米秸秆吸附Cu~(2+)的过程更符合准二级动力学模型。     

碳黑泥对废水中铅(Ⅱ)的吸附和回收利用

在试验室内对电镀、制革和采矿等工业中产生的大量含Pb2 废水用废弃碳黑泥进行了吸附处理,考察了吸附时间、初始pH值和Pb2 初始浓度对吸附反应的影响.结果表明,碳黑泥对Pb2 具有较强的吸附能力,pH值是影响吸附的主要因素,在pH≥5的弱酸性到中性溶液中碳黑泥对Pb2 的吸附性能较佳.Pb2 吸附的最初速率与浓度符合一级反应动力学;在稀溶液中吸附Pb2 基本符合Langmuir模型.还探讨了吸Pb2 碳黑泥回收铅的可行性.     

钠基膨润土对废水中Ni2+,Cu2+的吸附效果

为了提高膨润土吸附废水中Ni2+,Cu2+的效果,对其改性制备了钠基膨润土,考察了吸附时间、废水pH值以及Ni2+和Cu2+初始浓度对自制钠基膨润土吸附Ni2+,Cu2+效果的影响,分析了吸附等温线,并探讨了吸附机理。结果表明:钠基膨润土对Ni2+,Cu2+都有较好的吸附性能;初始阶段(前10 min)吸附很快,之后随时间延长吸附量提高甚微;pH值为6.2时,处理后的水质即可达国家排放标准;随着Ni2+,Cu2+初始浓度增加,去除率先增加后降低,而吸附量迅速增加,Ni2+和Cu2+初始浓度分别为25 mg/L和40 mg/L时,钠基膨润土对Ni2+,Cu2+的去除率均可达98.6%;钠基膨润土对Ni2+,Cu2+的吸附等温线符合Freundlich吸附等温式。     

改性竹炭对水溶液中Cu(Ⅱ)、Cd(Ⅱ)的吸附性能

采用不同方法对竹炭进行改性,寻求吸附效果最好的改性产品,并研究其对溶液中Cu2+、Cd2+的吸附性能,考察了吸附时间、溶液pH值、吸附温度和溶液初始浓度对吸附效果的影响,同时与未改性竹炭的吸附性能进行了对比。实验结果表明:相同条件下,氧化改性竹炭对Cu2+、Cd2+的吸附效果明显优于其他方法改性竹炭和未经改性的竹炭。吸附温度为15℃、25℃、45℃时,氧化竹炭对Cu2+的最大吸附量分别为6.653mg/g、6.702mg/g和7.897mg/g,而氧化竹炭对Cd2+的最大吸附量分别为1.700mg/g、1.826mg/g和2.282mg/g。氧化改性竹炭对Cu2+、Cd2+的吸附均符合Freundlich方程和Langmuir方程。实验证明,氧化竹炭是一种应用前景广泛的重金属离子吸附剂。     

纳米纤维素晶须双重接枝共聚物对Cu~(2+)的吸附

将丙烯酸和丙烯酰胺接枝到纳米纤维素晶须表面,制备出双重接枝共聚物。通过红外光谱和偏光显微镜分析表征双重接枝共聚物的官能团和液晶性能,研究了其对Cu2+的吸附性能,考察了吸附时间、吸附温度、pH值和初始浓度对吸附性能的影响。实验结果表明,丙烯酸和丙烯酰胺成功接枝到纳米纤维素晶须的表面;Cu2+的加入影响了双重接枝共聚物的液晶织构;在吸附时间为8h,吸附温度为35℃,pH值为6~8时,双重接枝共聚物对Cu2+具有最佳的吸附效果,最大的吸附容量为38.96mmol/g,吸附过程符合Langmuir方程。     

黑藻对铜离子和镍离子的生物吸附性能

为了经济实用地对废水进行处理,将来源广泛的黑藻制成粉末加入到含铜、镍离子的废水中,研究了其对废水中铜、镍离子的吸附作用,考察了溶液pH值、金属离子初始浓度、吸附剂用量、吸附时间和干扰离子等因素对吸附性能的影响.结果表明:黑藻吸附2种重金属离子的速度快,30 min即达到吸附平衡,适宜的pH值为5.0～6.0,干扰离子对Ni2+的影响大于对Cu2+的影响;黑藻对2种重金属的吸附均符合Langmiur,FreunoUich和Dubinin-Radushkevich(D-R)模型,对2种金属离子的吸附能力顺序是:Cu2+>Ni2+.     

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.     

海藻酸纤维对水溶液中Cu2+的吸附性能研究

以海藻酸钠为原料,通过湿法纺丝制备了海藻酸纤维,研究了水溶液中Cu2+的浓度、吸附时间、pH值以及纤维用量对海藻酸纤维吸附性能的影响,并对等温吸附模型进行了分析.结果表明,海藻酸纤维对Cu2+的吸附速率比较快,在10min基本达到吸附平衡;pH在4.5～5.5时纤维吸附作用最大,Cu2+浓度越高纤维吸附容量越大,纤维加入量越大Cu2+平衡浓度越低;Freundlich吸附等温式能较好的描述海藻酸纤维对Cu2+的平衡吸附过程.     

SBA-15介孔分子筛吸附电镀废水中Cu2＋的最佳条件和效果

为了开发新型高效廉价的吸咐材料,利用常压微波辐射法在酸性条件下以三嵌段共聚物（P123）为模板剂,制备了高度有序的SBA．15型介孔分子筛。研究了静态条件下SBA-15对电镀废水中Cu2＋的吸附,探讨了SBA-15用量、废水pH值、吸附时间、吸附温度对去除Cun效果的影响。结果表明：废水pH值为5．0,Cu2＋在0—1...     

Utilization of barley straws as biosorbents for Cu2+ and Pb2+ ions

The potential to remove Cu(2+) and Pb(2+) ion from aqueous solutions through biosorption using barley straw (BS) was investigated in batch experiments. The main parameters influencing Cu(2+) and Pb(2+) ion sorption on BS were: initial metal ion concentration, amount of adsorbent, contact time and pH value of solution. The influences of initial Cu(2+) and Pb(2+) ion concentration (0.1-1mM), pH (2-9), contact time (10-240 min) and adsorbent amount (0.1-1.0 g) have been reported. Equilibrium isotherms have been measured and modelled. The percent adsorption of Cu(2+) and Pb(2+) ions increased with an increase in pH and dosage of treated BS. The biosorptive capacity of the BS was dependent on the pH of Cu(2+) and Pb(2+) ion solution. Adsorption of Cu(2+) and Pb(2+) ion was in all cases pH dependent showing a maximum at equilibrium pH value at 6.0. The equilibrium sorption capacities of Cu(2+) and Pb(2+) after 2h were 4.64 mg/g and 23.20mg/g for BS, respectively. The adsorption data fit well with the Langmuir isotherm model and the experimental result inferred that complexation on surface, adsorption (chemisorption) and ion exchange is one of the major adsorption mechanisms for binding Cu(2+) and Pb(2+) ion to the sorbents.     

Adsorption of copper and lead in aqueous solution onto bentonite modified by 4'-methylbenzo-15-crown-5

The adsorption of heavy metal ions (Cu2+ and Pb2+) onto organobentonite modified by 4'-methylbenzo-15-crown-5 (MB15C5) from bentonite compared with natural bentonite (N-Bentonite) is described in this paper. The kinetic parameters of the models are calculated and discussed, and closely fitted a pseudo-second-order model in all cases. For bentonite modified with MB15C5 (MB15C5-Bentonite) and N-Bentonite, the equilibrium data closely fitted the Langmuir model and showed the following affinity order: Pb2+ > Cu2+, and the adsorption capacity of MB15C5-Bentonite is higher than that of N-Bentonite for Pb2+ and Cu2+. The effect of pH is examined over the range 1.5-6. The adsorption of Cu2+ and Pb2+ increases with increasing pH and the adsorption of Cu2+ and Pb2+ reaches a maximum at pH 3.5-6.     

Cu2+, Cd2+ and Pb2+ adsorption from aqueous solutions by pyrite and synthetic iron sulphide

In this study, removal of Cu(2+), Cd(2+) and Pb(2+) from aqueous solutions by adsorption onto pyrite and synthetic iron sulphide (SIS) was investigated as a function of pH, contact time, adsorbent dosage, initial metal concentration and temperature. It has been determined that the adsorption of metal ions onto both adsorbents is pH dependent and the adsorption capacities increase with the increasing temperature. The mechanisms governing the metal removal processes were determined as chemical precipitation at low pH (<3) due to H(2)S generation and adsorption at high pH (in the range of 3-6). The metal adsorption yields also increased with the increasing adsorbent dosage and contact time and reached to equilibrium for both adsorbents. The Cu(2+), Cd(2+) and Pb(2+) adsorption capacities of both adsorbents decrease in the order of Pb(2+)>Cu(2+)>Cd(2+). Except for cadmium, little fraction of copper and lead in the solid adsorption residues was desorbed in acidic media.     

Removal of lead ions in aqueous solution by hydroxyapatite/polyurethane composite foams

We have prepared hydroxyapatite/polyurehthane (HAp/PU) composite foams with two different HAp contents of 20 and 50 wt.% and investigated their removal capability of Pb2+ ions from aqueous solutions with various initial Pb2+ ion concentrations and pH values of 2-6. HAp/PU composite foams synthesized exhibited well-developed open pore structures which provide paths for the aqueous solution and adsorption sites for Pb2+ ions. With increasing the HAp content in the composites, the removal capability of Pb2+ ions by the composite foams increases owing to the higher adsorption capacity, whereas the removal rate is slower due to the less uniform dispersity of HAp in composite foams. The removal rate of Pb2+ ions is also slower with increasing the initial Pb2+ ion concentration in aqueous solutions. The removal mechanism of Pb2+ ion by the composites is varied, depending on the pH value of aqueous solution: the dissolution of HAp and precipitation of hydroypyromorphite is dominant at lower pH 2-3, the adsorption of Pb2+ ions on the HAp/PU composite surface and ion exchange reaction between Ca2+ of HAp and Pb2+ in aqueous solution is dominant at higher pH 5-6, and two removal mechanisms compete at pH 4. The equilibrium removal process of Pb2+ ions by the HAp/PU composite foam at pH 5 was described well with the Langmuir isotherm model, resulting in the maximum adsorption capacity of 150 mg/g for the composite foam with 50 wt.% HAp content.     

黑藻对含重金属废水中锌离子的吸附性能

黑藻能吸附重金属废水中的Zn2+,但对其的报道鲜见.研究了生物吸附剂黑藻对废水中Zn2+的吸附去除性能,考察了溶液pH值、Zn2+初始浓度、黑藻加入量和吸附时间对吸附效果的影响.同时通过EDX分析和等温吸附模型对黑藻吸附Zn2+的机理进行了研究.结果表明:在溶液pH值为6.0、黑藻加入量为2 g/L,吸附时间为30 min,Zn2+质量浓度为20 mg/L的条件下,黑藻对Zn2+的吸附率为85%,并且发现黑藻对Zn2+的吸附是阳离子交换过程,吸附符合Langmuir,Freuncllich和D-R等温吸附模型.