轮叶黑藻对铅的吸附特征及生物吸附机理研究

研究了轮叶黑藻对重金属铅的吸附特征,同时对吸附机理进行探讨.动力学研究结果表明,轮叶黑藻对铅有较快的吸附能力,10min后铅的去除率达到74.54%;20min后,吸附达到平衡.整个吸附过程符合伪二级动力学方程(R2=0.9910).Sips和Langmuir模型相比Freundlich而言,有着较好的拟合效果,表明轮叶黑藻对重金属铅的吸附属于单层吸附,相邻铅离子间的相互干扰可以忽略不计.红外光谱分析表明:轮叶黑藻叶片富含多种活性基团,羟基、羰基和羧基、C–O及C–N为主要作用基团.吸附铅后,轮叶黑藻叶片内K、Na、Ca、Mg含量明显下降,表明铅离子因产生离子交换而被吸附,且铅离子更易与二价的Ca和Mg产生离子交换.     

轮叶黑藻去除水体中氮磷能力研究

通过比较在不同梯度营养盐浓度下,沉水植物轮叶黑藻对水体中氮、磷的去除能力,研究得出：在不同营养条件下,轮叶黑藻对水体中总磷（TP）均有较好的去除效果,总氮（TN）处理浓度较高（15mg/L）时,轮叶黑藻对水体中的TN也有较好的去除效果;在一定的浓度范围内,轮叶黑藻的净化效果随水体中氮、磷等物质含量增加而增大,轮叶黑藻是一种很好的水体净化植物,在一些富营养化的水体中可以适当配置轮叶黑藻进行生态修复。     

两种水生植物对滇池草海富营养化水体水质的影响

通过模拟实验,比较了2种典型水生植物水葫芦和轮叶黑藻对滇池草海富营养化水体水质的影响.结果表明,在实验过程中,水葫芦同化吸收的氮、磷量分别比轮叶黑藻所同化吸收的量高109%和17%.在水生植物采收前,水葫芦处理组水体DO和pH值显著性低于对照组,电导率(EC)和氧化还原电位(Eh)显著性高于对照组,与轮叶黑藻处理组结果相反.水葫芦和轮叶黑藻处理组水体TN和TP浓度均显著低于对照组;相同初始种养量的情况下,试验初期轮叶黑藻处理组水体TN、TP及Chl-a浓度显著性低于水葫芦处理组,与试验后期结果相反.当水生植物采收后约50 d,水葫芦处理组水体TN、TP浓度均维持在采收前的低水平;轮叶黑藻处理组TN和TP浓度也维持在采收前水平,而Chl-a浓度较采收前有所上升.     

温度和pH对填埋场防渗帷幕吸附重金属离子的影响

以Pb（NO3）2和CdCl2作为模拟渗滤液,通过吸附实验,研究了体系pH值和温度变化对填埋场防渗帷幕吸附垃圾渗滤液中重金属离子的影响,探讨了防渗帷幕对重金属离子的吸附机理。研究结果表明：pH值是影响重金属离子吸附的重要因素,一般来说,弱酸性环境（pH=5～7）有利于防渗帷幕对铅和镉的吸附,随着体系pH值的升高,防渗帷幕对铅和镉的吸附率逐渐增大,且对铅的吸附率高于对镉的吸附率;温度是影响防渗帷幕吸附过程的重要环境因子之一,实验条件下,随着温度的升高,防渗帷幕对重金属离子的平衡吸附量均略微下降,说明季节不同防渗帷幕对渗滤液的阻滞能力不同。     

氨氮与镉单一和复合作用对沉水植物穗花狐尾藻和轮叶黑藻光合能力的影响

在水-土环境中,单一物质引起的污染很少,绝大多数污染是多种污染物质共存所造成的.利用碘量法测定溶解氧,研究了氨氮与镉单一和复合作用对沉水植物穗花狐尾藻和轮叶黑藻光合能力的影响.结果显示,氨氮浓度在4.0 mg·L^-1时,对轮叶黑藻有较强的胁迫作用,表现为光合作用的产氧量与呼吸作用的耗氧量均下降,而此浓度对穗花狐尾藻没有表现出胁迫作用;当镉处理浓度为0.2 mg·L^-1时,镉对2种沉水植物都表现出明显的胁迫效应,且对轮叶黑藻的胁迫作用更强;当镉与氨氮复合作用时,对轮叶黑藻产生联合毒害作用,但对穗花狐尾藻毒害作用较轻,可能原因是穗花狐尾藻所含的粗纤维比轮叶黑藻少,细胞壁上能结合重金属的位点较少,所以吸附的镉相应减少,毒性较小.实验结果表明在进行湖泊水生植物修复时,相对于轮叶黑藻,穗花狐尾藻更适合作为生态恢复的先锋物种.     

水源湖库中轮叶黑藻对水深变化的适应性中试

以上海市人工水源湖库——金泽水库为研究对象,进行水深及水位波动对轮叶黑藻生长影响的中试。试验周期为2个月,利用固定支撑杆上悬挂吊盆模拟不同水深和水位变化,研究其对轮叶黑藻生长的影响。试验结果表明:由于不同水深条件下的光照强度不同,水深和水位变化对轮叶黑藻的生物量、株高具有显著影响。在水位恒定的情况下,不同水深,轮叶黑藻的生物量差异较大,在0.6 m水深处达到最大值;轮叶黑藻的株高差异较大,在1.0 m水深处达到最大值。在水深为0.6或1.0 m时,小范围的波动(0.1～0.3 m)会促进黑藻的生长,水位波动太大则不利于轮叶黑藻的生长。     

铅模板交联壳聚糖对Pb(Ⅱ)的吸附性能

研究了脱乙酰度、粒度和溶液pH值等因素对壳聚糖吸附铅离子性能的影响,得到了最佳吸附条件为壳聚糖脱乙酰度100%和溶液pH值6.5.在该条件下,壳聚糖与铅离子作用后,用戊二醛交联,然后用盐酸洗脱铅离子,合成了铅交联壳聚糖模板树脂.探讨了交联剂量对交联壳聚糖吸附性能的影响以及铅模板交联壳聚糖对金属离子的吸附性能.结果表明,在CHO/NH₂为0.75:1时合成交联壳聚糖树脂对铅离子有最大吸附量,并且该树脂对铅离子和铜离子有较高的选择性,在酸性条件下不会发生软化和溶解,重复使用性良好.     

用稻米壳吸附去除废水中的铜离子和铅离子

稻壳是一种廉价的生物质吸附剂,用于从废水中去除铜、铅离子。研究了吸附时间、pH值、加入量与粒径、金属离子初始浓度等因素对吸附去除水中铜、铅离子的影响。实验结果表明：在最佳吸附条件下,稻壳对初始浓度为4mg/L铜离子、10m班铅离子的吸附量分别为0．62和2．09mg／g,去除率分别为63％和83％。同时,Cu^2＋和Pb^2＋在天然稻壳上吸附的热力学行为与Langmuir吸附等温式吻;动力学数据研究表明,吸附满足;隹二级动力学模型。稻壳将是去除废水中Cu^＋和Pb^2＋有潜质的材料。     

壳聚糖对沉水植物轮叶黑藻抗污能力的影响

利用化学需氧量(CODCr)分别为318 mg·L-1、157 mg·L-1、30 mg·L-1的生活污水培养轮叶黑藻.在各浓度生活污水中添加浓度为0.1%的壳聚糖,同时设不添加壳聚糖的对照组.通过对轮叶黑藻生长指标和叶绿素、可溶性蛋白质含量及抗氧化酶活性的测定,研究壳聚糖对沉水植物轮叶黑藻抗污能力的影响.结果显示,壳聚糖可明显促进轮叶黑藻主茎、根、分枝的生长,添加壳聚糖的试验组植株的叶绿素、可溶性蛋白质的含量比对照组高,且差异显著.壳聚糖能诱导黑藻超氧化物歧化酶和过氧化物酶活性增高,减轻膜脂质过氧化反应.研究结果提示壳聚糖能够促进黑藻生长,提高黑藻的抗污能力.     

锰钾矿型化合物的合成和表征及对Pb~(2+)的吸附

锰钾矿是一种对重金属离子有较强吸附作用的水处理剂。文章表征了由沉淀法合成的锰钾矿型化合物的多种理化特性,并应用于铅离子吸附的研究,对吸附反应机理进行了初步探讨。实验结果表明:合成的锰钾矿化合物属四方晶形,具有较大的比表面积和丰富的表面羟基,在中性pH值、低粒径条件下对铅离子具有较强的吸附能力。当铅离子的质量浓度<300mg/L时,吸附等温线符合Langmuir模型,最大理论吸附量为126.58mg/g。     

穗花狐尾藻铅吸附特征与机理

为探讨沉水植物对低浓度重金属废水的吸附特征,研究了不同重金属质量浓度及pH影响下,穗花狐尾藻鲜样在单一、二元和三元金属离子体系中对Pb2+的生物吸附特征及吸附机理. 结果表明,在单一Pb2+体系中,穗花狐尾藻对Pb2+的吸附能力随pH的升高而增强; 当初始ρ(Pb2+)为100mg/L、初始pH为6.5时,Pb2+吸附率可达80.95%. Cu2+和Zn2+的存在负向干扰穗花狐尾藻对Pb2+的吸附; 当初始ρ(Cu2+)和ρ(Pb2+)均为250mg/L时,Cu2+干扰下Pb2+吸附量降低为单一体系中Pb2+吸附量的62.40%. Sips和Langmuir模型的拟合效果优于Freundlich模型. 根据Langmuir模型模拟,穗花狐尾藻对Pb2+的理论最大吸附量(q_max)可达52.12mg/g. 红外光谱分析表明,—OH、—C=O、—COOH、C—O及C—H为主要作用基团. 吸附Pb2+后,溶液中矿质元素含量增加,ρ(Ca2+)和ρ(Mg2+)与初始ρ(Pb2+)达到极显著正相关(R_Ca2+=0.943,P<0.01;R_Mg2+=0.915,P<0.01). Pb2+更易与Ca2+和Mg2+产生离子交换而被吸附.      

Tolerance and biosorption of copper （Cu） and lead （Pb） by filamentous fungi isolated from a freshwater ecosystem

Filamentous fungi are able to accumulate significant amount of metals from their environment. The potential of fungal biomass as agents for biosorption of heavy metals from contaminated sediments is currently receiving attention. In the present study, a total of 41 isolates of filamentous fungi obtained from the sediment of the Langat River, Selangor, Malaysia were screened for their tolerance and uptake capability of copper (Cu) and lead (Pb). The isolates were identified as Aspergillus niger, A. fumigatus, Trichoderma asperellum, Penicillium simplicissimum and P. janthinellum. A. niger and P. simplicissimum, were able to survive at 1000 mg/L of Cu(II) concentration on Potato Dextrose Agar (PDA) while for Pb, only A. niger survived at 5000 mg/L concentration. The results showed that A. niger, P. simplicissimum and T. asperellum have a better uptake capacity for Pb compared to Cu and the findings indicated promising biosorption of Cu and Pb by these filamentous fungi from aqueous solution. The present study was also determined the maximum removal of Cu(II) and Pb(II) that was performed by A. niger. The metal removal which occurred at Cu(II) 200 mg/L was (20.910 0.581) mg/g and at 250 mg/L of Pb(II) was (54.046 0.328) mg/g.     

微生物吸附剂对重金属的吸附特性

从活性污泥中分离得到5株菌,检验了它们对重金属离子的吸附能力,其中类产碱假单胞菌(Pseudomonas pseudoalcaligenes)和藤黄微球菌(Micrococcus luteus)GC subgroup B对Cu(Ⅱ)和Pb(Ⅱ)离子吸附能力最强.考察了Cu(Ⅱ)和Pb(Ⅱ)离子分别在这2种菌体上的吸附特性研究表明,Langmuir型吸附模式能很好地描述Cu(Ⅱ)和Pb(Ⅱ)离子在这2种菌体上的吸附实验数据,其线形回归系数高达0.99,溶液pH值是影响吸附的最主要因素,pH=5～6是吸附Cu(Ⅱ)和Pb(Ⅱ)离子的适宜条件.吸附动力学实验研究表明,菌体对Cu(Ⅱ)和Pb(Ⅱ)离子的吸附可以分为迅速的细胞表面结合和缓慢的向细胞内的传输,稀HNO₃和H₂SO₄是Cu(Ⅱ)离子从Micrococcus luteus GC subgroup B菌体上有效的洗脱剂.     

Pb(Ⅱ) biosorption using chitosan and chitosan derivatives beads: Equilibrium,ion exchange and mechanism studies

The study examined the adsorption of Pb(II) ions from aqueous solution onto chitosan, chitosan-GLA and chitosan-alginate beads. Several important parameters influencing the adsorption of Pb(II) ions such as initial pH, adsorbent dosage and different initial concentration of Pb(II) ions were evaluated. The mechanism involved during the adsorption process was explored based on ion exchange study and using spectroscopic techniques. The adsorption capacities obtained based on non-linear Langmuir isotherm for ch...     

重金属离子的生物吸附容量与离子性质之间的关系

利用金属离子毒性评价和预测领域中的QSAR方法,探讨了重金属离子性质对生物吸附容量的影响．选用啤酒工业废弃的酿酒酵母为生物吸附剂,进行了10种金属离子Ag^＋,Cs^＋,Zn^＋,Pb^2＋,Ni^2＋,Cu^2＋,CO^2＋,Sr^2＋,Cd^2＋,Cr^3＋的生物吸附实验．选用22种参数来表征金属离子的物理化学性质,建立了金属的离子特性与生物吸附容量之间的关系．利用Langmuir方程计算得到酵母吸附金属离子的理论最大吸附量qmax,由大到小排序为Pb^2＋〉Ag^＋〉Cr^3＋〉Cu^2＋〉Zn^2＋〉Cd^2＋〉Co^2＋〉Sr^2＋〉Ni^2＋〉Cs^＋．离子性质与吸附量之间的线性拟合分析结果表明,共价指数Xm^2r与qmax具有良好的线性关系,共价指数越高,离子吸附量越大,金属离子与吸附剂表面官能团共价结合所占比重越大,键结合越牢固．对金属离子进行分类（按价态或离子的软硬性质）可以改善拟合效果．极化力Z^2／r、水解常数｜lgKOH｜、电离势,尸等多种物化性质与不含软离子的离子之间的理论最大吸附量也表现出良好的线性关系．     

Pb（II） biosorption using chitosan and chitosan derivatives beads： Equilibrium, ion exchange and mechanism studies

The study examined the adsorption of Pb(II) ions from aqueous solution onto chitosan, chitosan-GLA and chitosan-alginate beads. Several important parameters influencing the adsorption of Pb(II) ions such as initial pH, adsorbent dosage and di erent initial concentration of Pb(II) ions were evaluated. The mechanism involved during the adsorption process was explored based on ion exchange study and using spectroscopic techniques. The adsorption capacities obtained based on non–linear Langmuir isotherm for chitosan, chitosan-GLA and chitosan-alginate beads in single metal system were 34.98, 14.24 and 60.27 mg/g, respectively. However, the adsorption capacity of Pb(II) ions were reduced in the binary metal system due to the competitive adsorption between Pb(II) and Cu(II) ions. Based on the ion exchange study, the release of Ca2+, Mg2+, K+ and Na+ ions played an important role in the adsorption of Pb(II) ions by all three adsorbents but only at lower concentrations of Pb(II) ions. Infrared spectra showed that the binding between Pb(II) ions and the adsorbents involved mostly the nitrogen and oxygen atoms. All three adsorbents showed satisfactory adsorption capacities and can be considered as an e cient adsorbent for the removal of Pb(II) ions from aqueous solutions.     

Pb(Ⅱ) biosorption using chitosan and chitosan derivatives beads: Equilibrium, ion exchange and mechamsm studies

The study examined the adsorption of Pb(Ⅱ) ions from aqueous solution onto chitosan, chitosan-GLA and chitosan-alginate beads.Several important parameters influencing the adsorption of Pb(Ⅱ) ions such as initial pH, adsorbent dosage and different initial concentration of Pb(Ⅱ) ions were evaluated. The mechanism involved during the adsorption process was explored based on ion exchange study and using spectroscopic techniques. The adsorption capacities obtained based on non-linear Langmuir isotherm for chitosan, chitosan-GLA and chitosan-alginate beads in single metal system were 34.98, 14.24 and 60.27 mg/g, respectively. However,the adsorption capacity of Pb(Ⅱ) ions were reduced in the binary metal system due to the competitive adsorption between Pb(Ⅱ) and Cu(Ⅱ) ions. Based on the ion exchange study, the release of Ca~(2+), Mg~(2+), K~+ and Na~+ ions played an important role in the adsorption of Pb(Ⅱ) ions by all three adsorbents but only at lower concentrations of Pb(Ⅱ) ions. Infrared spectra showed that the binding between Pb(Ⅱ) ions and the adsorbents involved mostly the nitrogen and oxygen atoms. All three adsorbents showed satisfactory adsorption capacities and can be considered as an efficient adsorbent for the removal of Pb(Ⅱ) ions from aqueous solutions.     

Adsorption characteristics of copper, lead, zinc and cadmium ions by tourmaline

The adsorption characteristics of heavy metals： Cu（Ⅱ）, Pb（Ⅱ）, Zn（Ⅱ） and Cd（Ⅱ） ions on tourmaline were studied. Adsorption equilibrium was established. The adsorption isotherms of all the four metal ions followed well Langmuir equation. Tourmaline was found to remove heavy metal ions efficiently from aqueous solution with selectivity in the order of Pb（Ⅱ）〉Cu（Ⅱ）〉Cd（Ⅱ）〉Zn（Ⅱ）. The adsorption of metal ions by tourmaline increased with the initial concentration of metal ions increasing in the medium. Tourmaline could also increase pH value of metal solution.The maximum heavy metal ions adsorbed by tourmaline was found to be 78.86, 154.08, 67.25, and 66.67 mg/g for Cu（Ⅱ）, Pb（U）, Zn（Ⅱ） and Cd（U）, respectively. The temperature （25-55℃） had a small effect on the adsorption capacity of tourmaline. Competitive adsorption of Cu（Ⅱ）, Pb（Ⅱ）, Zn（Ⅱ） and Cd（Ⅱ） ions was also studied. The adsorption capacity of tourmaline for single metal decreased in the order of Pb〉Cu〉Zn 〉Cd and inhibition dominance observed in two metal systems was Pb〉Cu, Pb〉Zn, Pb〉Cd, Cu〉Zn, Cu〉Cd, and Cd〉Zn.     

好氧颗粒污泥细菌藻酸盐对Cu~(2+)的生物吸附和机制探讨

以好氧颗粒污泥中提取的细菌藻酸盐为原料制备干藻酸钙吸附剂,对水溶液中的Cu2+进行了吸附研究.对比了不同pH值和吸附剂投加量对吸附性能的影响,同时对吸附过程进行了模型拟合,测定了该吸附剂的解吸性能,并用傅立叶变换红外二阶导数光谱和原子力显微镜分析对吸附机制进行了探讨.结果表明,藻酸钙对Cu2+的吸附反应是一个比较快速的过程.当Cu2+初始浓度为100 mg/L,吸附剂投加量为0.7g/L时,吸附最佳pH值为4,吸附能力为67.67 mg/g.吸附过程可用Langmuir和Freundlich模型来描述.好氧颗粒污泥藻酸钙吸附剂对Cu2+的吸附过程中有离子交换和pH值升高现象发生,溶液中的Cu2+与吸附剂上Ca2+交换的同时需要有H+的参与来维持电荷平衡.傅立叶变换红外二阶导数光谱和原子力显微镜分析表明,好氧颗粒污泥藻酸钙吸附剂中MG嵌段与Cu2+和Ca2+结合的方式不同,Cu2+能与吸附剂表面的MG嵌段发生螯合,使藻酸钙表面的结构更加有序.以100 mmol/L HCl为解吸剂,解吸效率可达到91%.