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.     

Biosorption of mercury by Macrocystis pyrifera and Undaria pinnatifida: Influence of zinc, cadmium and nickel

The article investigated the adsorption of Hg(II) on Macrocystis pyrifera and Undaria pinnatifida in monometallic system and in the presence of Zn(II), Cd(II) and Ni(II).     

酿酒酵母吸附Zn(Ⅱ)过程中阳离子(K+，Mg2+，Na+，Ca2+)的变化分析

研究了酿酒酵母无缓冲溶液体系吸附Zn(Ⅱ)的过程中各种阳离子的变化情况.研究结果表明,当Zn(Ⅱ)的初始浓度是0.08～0.8 mmol·L^-1,酵母浓度约1 g·L^-1,初始pH为5.65,反应38h内,酵母的Zn(Ⅱ)吸附量为74.8～654.8μmol·g^-1,去除率达到76.4%～92.8%,pH值升高0.55～1.28.吸附过程中酵母首先快速释放大量K⁺,其次是Mg²⁺和Na⁺,Ca²⁺的释放量较少,数量级一般可分别达到几百、几十和几个μmol·g^-1.以离子交换为基础计算的各阳离子释放量总和一般超过Zn(Ⅱ)的吸附量,证明酵母吸附Zn(Ⅱ)的机理之一是离子交换,但不唯一.无缓冲溶液体系酵母吸附Zn(Ⅱ)的过程中溶液pH值升高,H⁺被吸收,K⁺等阳离子释放,是生物体细胞的本质属性,与Zn(Ⅱ)是否存在无关,但是Zn(Ⅱ)可以促进阳离子的释放以及降低酵母对H+的吸收,也反映出Zn(Ⅱ)与H⁺之间可以竞争细胞表面吸附位.死酵母的吸附量低于未处理酵母,与阳离子交换能力关系不大,可能与细胞表面变形导致Zn(Ⅱ)吸附困难有关.     

细菌X07吸附Cr(Ⅵ)的研究

从不同来源的样品中分离出一株吸附Cr(Ⅵ)较强的菌株X07,经鉴定为蜡状芽孢杆菌(Bacillus.cereus)。通过吸附实验探讨了X07死菌体对Cr(Ⅵ)的吸附特性,结果表明,X07死菌体吸附Cr(Ⅵ)的最适pH值为6.0;其吸附Cr(Ⅵ)是一个快速、非温度依赖过程,吸附50min达到饱和,在最初的5min内,吸附量达到最大吸附量的76.8%;菌体浓度的增加有利于对Cr(Ⅵ)的吸附:其吸附等温线符合Langmuir和Freundlich吸附模型,在试验的条件下,对Cr(Ⅵ)的饱和吸附容量为146.9mg/g干菌体。     

不同乙酸浓度对聚磷菌厌氧释磷的影响

采用SBR工艺培养生物强化除磷活性污泥,通过厌氧批式试验对反应器中的高效除磷好氧颗粒污泥进行厌氧乙酸吸收动力学研究。结果表明：聚磷菌对乙酸吸收速率不受乙酸浓度影响,但受胞内聚磷浓度影响。当胞内聚磷浓度低于60mg—P／g—VSS时,乙酸吸收速率与聚磷浓度呈Monod关系。进而求出了聚磷菌吸收乙酸的动力学方程,其中最大乙酸吸收速率为3mg—HAe／g—VSS·min,胞内聚磷的饱和系数为20mg—P／g—Vss。另外,在pH为中性条件下,每吸收1mg乙酸,聚磷菌释放约0．5mg磷。     

Isolation,identification, Pb(Ⅱ) biosorption isotherms and kinetics of a lead adsorbing Penicillium sp. MRF-1 from South Korean mine soil

A heavy metal contaminated soil sample collected from a mine in Chonnam Province of South Korea was found to be a source of heavy metal adsorbing biosorbents. Chemical analyses showed high contents of lead (Pb) at 357 mg/kg and cyanide (CN) at 14.6 mg/kg in the soil. The experimental results showed that Penicillium sp. MRF-1 was the best lead resistant fungus among the four individual metal tolerant fungal species isolated from the soil. Molecular characterization of Penicillium sp. MRF-1 was determined using ITS regions sequences. E ects of pH, temperature and contact time on adsorption of Pb(II) by Penicillium sp. MRF-1 were studied. Favorable conditions for maximum biosportion were found at pH 4 with 3 hr contact time. Biosorption of Pb(II) gradually increased with increasing temperature. E cient performance of the biosorbent was described using Langmuir and Freundlich isotherms. Adsorption kinetics was studied using pseudo first-order and pseudo second-order models. Biosorbent Penicillium sp. MRF-1 showed the maximum desorption in alkali conditions. Consistent adsorption/desorption potential of the biosorbent in repetitive cycles validated the e cacy of it in large scale. SEM studies given notes on surface modification of fungal biomass under metal stress and FT-IR results showed the presence of amino groups in the surface structure of the biosorbent. In conclusion, the new biosorbent Penicillium sp. MRF-1 may potentially be used as an inexpensive, easily cultivatable material for the removal of lead from aqueous solution.     

纳米Fe3O4负载的浮游球衣菌去除重金属离子的工艺研究

以纳米Fe₃O₄负载浮游球衣菌（Sphaerotilus natans）制备复合生物吸附剂,对此吸附剂进行表征并考察了其吸附水中重金属离子的性能.红外光谱分析表明,此复合生物吸附剂表面的主要活性基团为酰胺基（—CONH—）和羟基（—OH）.吸附性能研究表明,菌含量和流量是影响复合生物吸附剂吸附重金属离子的主要因素,在Cu²⁺初始浓度c₀<20 mg/L,菌含量1.5 g/L（菌/ Fe₃O₄＝3∶2）,流量0.96 L/h 时吸附剂对Cu²⁺的吸附效果最好;用稀盐酸对复合生物吸附剂进行再生,吸附剂可重复使用10次以上,再生液可重复使用3次; 吸附选择性为：Pb²⁺ > Cu²⁺ > Zn²⁺>Cd²⁺.     

螯合剂添加对蜈蚣草修复砷污染土壤效果的影响分析

用盆栽试验的方法,研究了3种可生物降解螯合剂谷氨酸二乙酸四钠（GLDA）、甲基甘氨酸二乙酸（MGDA）、乙二胺二琥珀酸（EDDS）和1种传统螯合剂乙二胺四乙酸（EDTA）,在不同浓度（0,1.25,2.50,5.00,10.00 mmol/kg）下对蜈蚣草吸收土壤中As的影响。研究表明:4种螯合剂在1.25 mmol/kg时均能显著提高蜈蚣草生物量。EDDS在10 mmol/kg时根际土壤生物有效态As的含量最高,较空白组CK提高了69.2%。GLDA在10.00 mmol/kg时根际土壤As较原土壤降低了28.84%。浓度为5.00 mmol/kg的EDDS处理的蜈蚣草对As的富集系数BCF最高,为7.99,是CK的1.70倍。综合蜈蚣草生物量和对As的BCF值来看,5.00 mmol/kg MGDA地上部分对As积累量最大,其值为2648.65 μg/pot,较CK提高了65.92%。已被广泛应用于修复土壤Cd和Zn领域的新型螯合剂GLDA和MGDA在修复土壤As污染同样具有明显的潜力。     

基于孔结构调控强化BEAC工艺生物降解效能

为进一步提升生物增强活性炭工艺（BEAC）中炭表面的功能菌载持量及生物降解活性,通过CO₂接触氧化与深度活化相结合的压块炭制备改进工艺对煤质净水炭的孔结构进行调控.结果表明：基于改进工艺制备的XHIT型炭的中孔容积（0.7041cm³/g）及中孔容积率（63.95%）显著提高,其表面复合功能菌初始固定化生物量达到9.13mmol/g（以P计）,增殖速率为2.123mmol/（g·d）（以P计）.深度活化产生的高含氧量（9.96%）显著降低了XHIT型炭表面吸附作用对水中溶解氧亲和度（（0.42±0.07）mg DO/L）,功能菌生物降解对水中溶解氧的利用效率达到91.17%.基于XHIT型炭构建的BEAC工艺（通水倍数为39.50m³/kg）对松花江水源水中的微量有机污染物（COD_Mn）的平均去除率达到（70.65±15.22）%,有机污染物累积去除量达到94655.50mg COD_Mn/kg炭.     

纳米Fe3O4负载的浮游球衣菌去除Cr(Ⅵ)的研究

以纳米Fe₃O₄负载浮游球衣菌（Sphaerotilus natans）为复合生物吸附剂,考察了其对Cr(Ⅵ)的吸附性能,并对生物吸附机理进行了初步研究.结果表明,pH值是影响复合生物吸附剂吸附Cr(Ⅵ)的主要因素,吸附的最佳pH为2～3;用此复合生物吸附剂对Cr(Ⅵ)进行吸附,其单位吸附量为0.0217 mmol/g.用HCl对其进行再生,再生率在90％以上;—CONH₂和—NH—是菌体吸附Cr(Ⅵ)的主要活性基团,静电吸引是复合生物吸附剂吸附Cr(Ⅵ)的主要机理之一.     

阴离子交换纤维吸附与解吸亚硝酸根的研究

本文对聚乙烯醇阴离子交换纤维(Poly vinylalcohol anion exchange fiber)吸附与解吸亚硝酸根分别作了动态及静态试验。结果表明,NO_2~-在PVAF上吸附与解吸速度快、再生容易、使用寿命长,吸附特征符合Langmuir吸附等温式,饱和吸附量为1.7m mol/g。其吸附率与温度、NO_2~-浓度、滤速、pH值、共存阴离子种类有关。洗脱率与洗脱剂种类、浓度有关。     

Arsenic uptake, accumulation and phytofiltration by duckweed （Spirodela polyrhiza L.）

This study investigates arsenic (As) accumulation and tolerance of duckweed Spirodela polyrhiza L: and its potential for As phytofiltration. S. polyrhiza was able to survive in high concentration of As(V) solution: The EC50 values ( SE) based on the external As(V) were (181.66 20.12) mol/L. It accumulated (999 95) mg As/kg dw when exposed in 320 mol/L As(V) solution for one week, and was able to take up appropriately 400 mg As/kg dw in tissues without a significant biomass loss. The EC50 values (the e ective concentration of As(V) in the nutrient solution that caused a 50% inhibition on biomass production) was (866 68) mg/kg dw for the tissues, indicating that S. polyrhiza had a high capability of As accumulation and tolerance. The uptake kinetic parameters Vmax was (55.33 2.24) nmol/(g dw min) and Km was (0.144 0.011) mmol/L. Within 72 hr, S. polyrhiza decreased As concentration in the solution from 190 to 113 ng/mL with a removal rate of 41%. The study suggested that this floating aquatic plant has some potential for As phytofiltration in contaminated water bodies or paddy soils.     

Immobilization study of biosorption of heavy metal ions onto activated sludge

Activated sludge was immobilized into Ca-alginate beads via entrapment, and biosorption of three heavy metal ions, copper(Ⅱ), zinc(Ⅱ), and chromimum(Ⅱ), from aqueous solution in the concentration range of 10-100 mg/L was studied by using both entrapped activated sludge and inactivated free biomass at pH≤5. A biphasic metal adsorption pattern was observed in all immobilized biomass experiments. The biosorption of metal ions by the biosorbents increased with the initial concentration increased in the medium. The adsorption rate of immobilized pre-treated activated sludge(PAS) was much lower than that of free PAS due to the increase in mass transfer resistance resulting from the polymeric matrix. Biosorption equilibrium of beads was established in about 20 h and the adsorbed heavy metal ions did not change further with time. No significant effect of temperature was observed in the test for free biomass while immobilized PAS appeared to be strong temperature dependent in the test range of 10 and 40℃.Besides, the content of activated sludge in the calcium alginate bead has an influence on the uptake of heavy metals. The sorption equilibrium was well modeled by Langmuir isotherm, implying monomolecular adsorption mechanism. Carboxyl group in cell wall played an important role in surface adsorption of heavy metal ions on PAS.     

Biosorption characteristics of unicellular green alga Chlorella sorokiniana immobilized in loofa sponge for removal of Cr（Ⅲ）

Loofa sponge （LS） immobilized biomass of Chlorella sorokiniana （LSIBCS）, isolated from industrial wastewater, was investigated as a new biosorbent for the removal of Cr（Ⅲ） from aqueous solution. A comparison of the biosorption of Cr（Ⅲ） by LSIBCS and free biomass of C. sorokiniana （FBCS） from 10-300 mg Cr（Ⅲ）/L aqueous solutions showed an increase in uptake of 17.79% when the microalgal biomass was immobilized onto loofa sponge. Maximum biosorption capacity for LSIBCS and FBCS was found to be 69.26 and 58.80 mg Cr（Ⅲ）/g biosorbent, respectively, whereas the amount of Cr（Ⅲ） ions adsorbed onto naked LS was 4.97 mg/g. The kinetics of Cr（Ⅲ） biosorption was extremely rapid and equilibrium was established in about 15 and 20 min by LSIBCS and FBCS, respectively. The biosorption equilibrium was well defined by Langmuir adsorption isotherm model. The biosorption kinetics followed the pseudo-second order kinetic model. The biosorption was found to be pH dependent and the maximum sorption occurred at the solution pH 4.0. Desorption studies showed that 98% of the adsorbed Cr（Ⅲ） could be desorbed with 0.1 mol/L HNO3, while other desorbing agents were less effective in the order： EDTA 〉 H2SO4 〉 CH3COOH 〉 HCl. The regenerated LSIBCS retained 92.68% of the initial Cr（Ⅲ） binding capacity up to five cycles of reuse in continuous flow-fixed bed columns. The study revealed that LSIBCS could be used as an effective biosorbent for the removal of Cr（Ⅲ） from wastewater.     

毛木耳子实体对Ni(Ⅱ)生物吸附的优化研究

采用响应曲面法研究了起始pH值、固液比、重金属初始浓度等因素对毛木耳子实体吸附Ni(Ⅱ)的影响.采用中心组合法及批量实验,对吸附过程进行优化,确定了最优条件.结果表明,起始pH值、固液比、Ni(Ⅱ)初始浓度对吸附过程均有显著影响(P＜o.0001),毛木耳子实体吸附Ni(Ⅱ)最佳条件为pH5.41,固液比6.00g/L...     

Biosorption characteristics of unicellular green alga Chlorella sorokiniana immobilized in loofa sponge for removal of Cr(Ⅲ)

Loofa sponge (LS) immobilized biomass of Chlorella sorokiniana (LSIBCS), isolated from industrial wastewater, was investigated as a new biosorbent for the removal of Cr(Ⅲ) from aqueous solution. A comparison of the biosorption of Cr(Ⅲ) by LSIBCS and free biomass of C. sorokiniana (FBCS) from 10-300 mg Cr(Ⅲ)/L aqueous solutions showed an increase in uptake of 17.79% when the microalgal biomass was immobilized onto loofa sponge. Maximum biosorption capacity for LSIBCS and FBCS was found to be 69.26 and 58.80 mg Cr(Ⅲ)/g biosorbent, respectively, whereas the amount of Cr(Ⅲ) ions adsorbed onto naked LS was 4.97 mg/g. The kinetics of Cr(Ⅲ) biosorption was extremely rapid and equilibrium was established in about 15 and 20 min by LSIBCS and FBCS,respectively. The biosorption equilibrium was well defined by Langmuir adsorption isotherm model. The biosorption kinetics followed the pseudo-second order kinetic model. The biosorption was found to be pH dependent and the maximum sorption occurred at the solution pH 4.0. Desorption studies showed that 98% of the adsorbed Cr(Ⅲ) could be desorbed with 0.1 mol/L HNO3, while other desorbing agents were less effective in the order: EDTA ＞ H2SO4 ＞ CH3COOH ＞ HCl. The regenerated LSIBCS retained 92.68% of the initial Cr(Ⅲ) binding capacity up to five cycles of reuse in continuous flow-fixed bed columns. The study revealed that LSIBCS could be used as an effective biosorbent for the removal of Cr(Ⅲ) from wastewater.     

壳聚糖/聚氨酯多孔材料对Cu~(2+)、Cd~(2+)的吸附研究

将壳聚糖、聚醚多元醇、甲苯二异氰酸酯混合发泡,制备了壳聚糖/聚氨酯(Cs/PU)多孔复合材料,利用原子吸收光谱研究了Cs/PU对水中Cu2+、Cd2+的吸附能力。结果表明:在28℃条件下,当吸附时间为30min,溶液pH=4～5时,Cu2+的最高去除率为96.67%,溶液pH=6～7时,Cd2+的去除率为95.67%。Cd2+、Cu2+的饱和吸附率容量分别为28.78mg/g和25.32mg/g。两种金属离子共存时,Cs/PU对Cu2+的选择性大于Cd2+。     

非活性菌丝体对水中铅离子的吸附

从发酵工业选取９种废弃的菌丝体,考察其对水中Ｐｂ离子的吸附行为。结果表明,其中半数菌丝体为Ｐｂ的最大吸附量接近或超过１００ｍｇ／ｇ干重,对林可链霉菌的吸附等温线和ｐＨ值、温度、共存离子等因素影响Ｐｂ离子吸附行为的研究表明,该菌丝体对Ｐｂ的吸附量随ｐＨ降低而升高,温度对吸附的影响不大,共存Ｃｕ＾２＋使Ｐｂ的吸附量降低,而共存Ｚｎ＾２＋无明显影响。     

造纸污泥生物炭对四环素的吸附特性及机理

以造纸污泥为原料,在限氧条件下,通过控制热解温度（300,500和700℃）,制备生物炭（SBC300、SBC500和SBC700）,比较了3种生物炭的基本理化性质;以四环素（TC）为目标污染物,研究了造纸污泥生物炭（SBC）对TC的吸附特性及机理.结果表明,SBC对TC的吸附以化学吸附为主,吸附平衡时,SBC300对TC的去除率最低,为38.8%,SBC700的去除率最高,为54.1%;同时Langmuir模型能更好地描述此吸附过程,且最大吸附量依次为SBC700（63.8mg/g） > SBC500（50.6mg/g） > SBC300（40.0mg/g）.热力学分析表明,SBC对TC的吸附为自发且吸热的过程.pH值影响TC的存在形态及SBC的表面带电情况,对吸附过程有较大影响.通过吸附等温线分解法定量描述了表面吸附作用及分配作用的贡献率,结合FTIR分析,表明SBC对TC的吸附可能是分配作用、静电作用、氢键作用、π-π EDA作用及离子交换作用等共同作用的结果.     

活性炭吸附处理洗毛废水的研究

通过活性炭吸附两种不同处理方法处理后的洗毛废水。研究了活性炭的吸附容量和吸附机理。结果表明：活性炭吸附无机酸酸化处理后,废水和高分子絮凝剂处理后,废水中COD的吸附容量分别为：70mg／g和43mg／g。进一步研究发现,两种废水中小分子组分和疏水性组分的含量差异是造成活性炭吸附效果差异的主要原因。