Removal of Ni(II) and Cu(II) ions using native and acid treated Ni-hyperaccumulator plant Alyssum discolor from Turkish serpentine soil

Alyssum discolor biomass was collected from serpentine soil and was used for removal of metal ions. The plant species grown on serpentine soils are known to be rich with metals ions and thus have more capability for accumulating heavy metals. Native and acid-treated biomass of A. discolor (A. discolor) were utilized for the removal of Ni(II) and Cu(II) ions from aqueous solutions. The effects of contact time, initial concentration, and pH on the biosorption of Ni(II) and Cu(II) ions were investigated. Biosorption equilibrium was established in about 60 min. The surface properties of the biomass preparations were varied with pH, and the maximum amounts of Ni(II) and Cu(II) ions on both A. discolor biomass preparations were adsorbed at pH 5.0. The maximum biosorption capacities of the native, and acid-treated biomass preparations for Ni(II) were 13.1 and 34.7 mg g⁻¹ and for Cu(II) 6.15 and 17.8 mg g⁻¹ dry biomass, respectively. The biosorption of Ni(II) and Cu(II) ions from single and binary component systems can be successfully described by Langmuir and Freundlich isotherms. When the heavy metal ions were in competition, the amounts of biosorbed metal ions on the acid treated plant biomass were found to be 0.542 mmol g⁻¹ for Ni(II) and 0.162 mmol g⁻¹ for Cu(II), the A. discolor biomass was significantly selective for Ni(II) ions. The information gained from these studies was expected to indicate whether the native, and acid-treated forms can have the potential to be used for the removal and recovery of Ni(II) ions from wastewaters.     

满江红干体对锌离子的生物吸附

以满江红干体为生物吸附剂，研究了不同条件下对废水中Zn²⁺的净化作用。结果表明，满江红干体对Zn²⁺的吸附是一个快速的过程，前5 min的吸附量达到最大吸附量的62.9%，30 min达到吸附平衡；初始pH值对Zn²⁺的吸附有显著的影响，最适pH值为6；随着干体量的增加，吸附率逐渐提高而吸附量则降低；随着Zn²⁺初始浓度的增加，吸附率逐渐降低而吸附量则提高。满江红干体对Zn²⁺的吸附符合Langmuir吸附等温线方程，最大吸附容量达57.5 mg/g。5次吸附解吸循环实验数据表明，重复次数和再生处理对满江红干体的吸附能力没有产生显著影响。因此，满江红干体在处理含Zn²⁺废水中的重复使用是可行的。     

非固定化和固定化啤酒酵母对Cd^2＋和Cu^2＋的吸附特性研究

对比了不同吸附剂对重金属的吸附效果，同时研究了啤酒酵母的固定化方法、菌体用量对吸附效果的影响、非同定化和固定化啤酒酵母吸附热力学特性。研究结果表明，非固定化死啤酒酵母对Cd^2＋的单位菌体吸附量是常用吸附剂活性炭的3倍；由1：3的海藻酸钠与碱处理啤酒酵母（w／w）制得的固定化颗粒吸附效果最好；菌体用量的增加会降低单位菌体对重金属的吸附量；啤酒酵母对重金属的吸附位点有限，Cd^2＋的实际最大吸附量为13．95mg／g，Cu^2＋为7．67μg／g。非固定化和固定化啤酒酵母对Cu^2＋和Cd^2＋的等温吸附过程均可用Linear方程、Langmuir方程和Freundlich方程来进行拟合，但非同定化啤酒酵母以Langmuir方程最优，其拟合计算的最大吸附量qmzxCd和qmxxCu分别为13．96mg／g和8．01mg／g；固定化啤酒酵母以Freundlich方程最优，实际最大吸附量Cd为75．41mg／g，Cu为66．58mg／g。     

Evaluation of different isotherm models,kinetic, thermodynamic,and copper biosorption efficiency of Lobaria pulmonaria (L.) Hoffm.

The biosorption characteristics of Cu(II) ions from aqueous solution using Lobaria pulmonaria (L.) Hoffm. biomass were investigated. The biosorption efficiency of Cu(II) onto biomass was significantly influenced by the operating parameters. The maximum biosorption efficiency of L. pulmonaria was 65.3% at 10 mg/L initial metal concentration for 5 g/L lichen biomass dosage. The biosorption of Cu(II) ions onto biomass fits the Langmuir isotherm model and the pseudo-second-order kinetic model well. The thermodynamic parameters indicate the feasibility and exothermic and spontaneous nature of the biosorption. The effective desorption achieved with HCl was 96%. Information on the nature of possible interactions between the functional groups of the L. pulmonaria biomass and Cu(II) ions was obtained via Fourier transform infrared (FTIR) spectroscopy. The results indicated that the carboxyl (–COOH) and hydroxyl (–OH) groups of the biomass were mainly involved in the biosorption of Cu(II) onto L. pulmonaria biomass. The L. pulmonaria is a promising biosorbent for Cu(II) ions because of its availability, low cost, and high metal biosorption and desorption capacities.

Implications: Lobaria pulmonaria is a promising biosorbent for Cu(II) ions because of its availability, low cost, and high metal biosorption and desorption capacities. To the best of our knowledge, this is the first paper on the biosorption Cu by L. pulmonaria.     

Potential use of Caulerpa fastigiata biomass for removal of lead: kinetics, isotherms, thermodynamic, and characterization studies

The present study attempts to analyze the biosorption trend of biosorbent Caulerpa fastigiata (macroalgae) biomass for removal of toxic heavy metal ion Pb (II) from solution as a function of initial metal ion concentration, pH, temperature, sorbent dosage, and biomass particle size. The sorption data fitted with various isotherm models and Freundlich model was the best one with correlation coefficient of 0.999. Kinetic study results revealed that the sorption data on Pb (II) with correlation coefficient of 0.999 can best be represented by pseudo-second-order. The biosorption capacity (q _e ) of Pb (II) is 16.11?±?0.32 mg g^?1 on C. fastigiata biomass. Thermodynamic studies showed that the process is exothermic (ΔH° negative). Free energy change (ΔG°) with negative sign reflected the feasibility and spontaneous nature of the process. The SEM studies showed Pb (II) biosorption on selective grains of the biosorbent. The FTIR spectra indicated bands corresponding to –OH, COO^?, –CH, C?=?C, C?=?S, and –C–C– groups were involved in the biosorption process. The XRD pattern of the C. fastigiata was found to be mostly amorphous in nature.     

The arbuscular mycorrhizal fungus Glomus mosseae can enhance arsenic tolerance in Medicago truncatula by increasing plant phosphorus status and restricting arsenate uptake

A pot experiment examined the biomass and As uptake of Medicago truncatula colonized by the arbuscular mycorrhizal (AM) fungus Glomus mosseae in low-P soil experimentally contaminated with different levels of arsenate. The biomass of G. mosseae external mycelium was unaffected by the highest addition level of As studied (200 mg kg⁻¹) but shoot and root biomass declined in both mycorrhizal and non-mycorrhizal plants, indicating that the AM fungus was more tolerant than M. truncatula to arsenate. Mycorrhizal inoculation increased shoot and root dry weights by enhancing host plant P nutrition and lowering shoot and root As concentrations compared with uninoculated plants. The AM fungus may have been highly tolerant to As and conferred enhanced tolerance to arsenate on the host plant by enhancing P nutrition and restricting root As uptake.     

Highly efficient biosorptive removal of lead from industrial effluent

This study has been focused on the efficient removal of Pb (II) from contaminated waters by biosorption using plant derived material. Accordingly an indigenous shrub, Tinospora cordifolia has been identified as the most suitable biosorbent. The plant biomass was subjected to optimization of various parameters such as the pH, equilibrium time, dosage, concentration, temperature and the applicable adsorption models. The optimum pH identified was 4.0 with a contact time of 60 min at room temperature (27 ± 2 °C). The experimental data fitted well to adsorption isotherms and the uptake capacity of Pb (II) was found to be 20.83 and 63.77 mg/g in batch mode and column mode, respectively. The high correlation factors obtained for Langmuir and Freundlich models indicated that both models were obeyed by the system. Kinetic study for adsorption of Pb (II) follow only pseudo second order rate of reaction. The accumulation of lead in biomass was confirmed by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis. The FTIR analysis indicated the involvement of hydroxyl (−OH), alkenes (=CH) and carbonyl group (C = O) chelates in metal binding. The SEM and EDX analysis showed the structural changes and the filling of voids in the biomass thus, it indicated the metal-binding mechanism. In elution studies, the 0.1 M Na₂CO₃ was found to be the best with about 71% elution of the adsorbed metal. The biomass was then used for the removal of Pb (II) in synthetic and real wastewater samples from a lead-acid battery industry. It is also noteworthy that even at a very high concentration of 450 mg/L, the biomass was showing about 92% removal. The result is to establish the efficacy of T. cordifolia as a very good bioadsorbent for the Pb (II) removal from contaminated water.

     

Biosorption characteristics of Bacillus gibsonii S-2 waste biomass for removal of lead (II) from aqueous solution

Lead (II) has been as one of the most toxic heavy metals because it is associated with many health hazards. Therefore, people are increasingly interested in discovering new methods for effectively and economically scavenging lead (II) from the aquatic system. Recent studies demonstrate biosorption is a promising technology for the treatment of pollutant streams. To apply these techniques, suitable adsorbents with high efficiency and low cost are demanded. The waste biomass of Bacillus gibsonii S-2 biosorbent was used as low-cost biosorbent to remove metallic cations lead (II) from aqueous solution. To optimize the maximum removal efficiency, the effect of pH and temperature on the adsorption process was studied. The isotherm models, kinetic models and thermodynamic parameters were analysed to describe the adsorptive behaviour of B. gibsonii S-2 biosorbent. The mechanisms of lead (II) biosorption were also analysed by FTIR and EDX. The results showed that the optimum pH values for the biosorption at three different temperatures, i.e. 20, 30 and 40 °C, were determined as 4. The equilibrium data were well fitted to Langmuir model, with the maximum lead (II) uptake capacities of 333.3 mg?g^?1. The kinetics for lead (II) biosorption followed the pseudo-second-order kinetic equation. The thermodynamic data showed that the biosorption process were endothermic (?G?<?0), spontaneous (?H?>?0) and irreversible (?S?>?0). The mechanism of lead (II) biosorption by the waste biomass of B. gibsonii S-2 biosorbent could be a combination of ion exchange and complexation with the functional groups present on the biosorbent surface. The application of the waste biomass of B. gibsonii S-2 for lead (II) adsorption, characterized with higher lead (II) sorption capacity and lower cost, may find potential application in industrial wastewater treatment.     

厌氧颗粒污泥藻酸盐对铜离子的吸附研究

从厌氧颗粒污泥中成功提取出细菌藻酸盐并制备成藻酸钙吸附剂,研究其对水中Cu~(2+)的吸附性能。实验结果表明,接触时间、Cu~(2+)初始浓度和溶液初始pH是影响Cu~(2+)吸附性能的重要因素。吸附等温线研究表明,Langmuir模型比Freundlich模型能更好地描述吸附过程。Cu~(2+)在藻酸钙上的吸附动力学过程可以很好地用Pseudo二级动力学方程来描述。以100 mmol/L HCI为解吸剂,可有效洗脱藻酸钙上95%的Cu~(2+),实现Cu~(2+)的回收。     

棘孢曲霉（Aspergillus aculeatus）对Pb2＋和Cd2＋的吸附特征

为了研究棘孢曲霉（Aspergillus aculeatus）对溶液中Pb^2＋和Cd^2＋吸附过程的特征，分别从动力学、热力学和吸附等温线三方面进行了实验，同时还研究了pH、温度、时间、重金属离子起始浓度和吸附剂用量对吸附过程的影响。等温吸附过程可以用Langmuir方程来描述。在实验设定条件下，棘孢曲霉对Pb^2＋和Cd^2＋最大吸附量分别为71.2 mg/g和59.8 mg/g；动力学实验数据很好的符合二级     

Biosorption of synthetic dyes (Direct Red 89 and Reactive Green 12) as an ecological refining step in textile effluent treatment

With the use of cost-effective natural materials, biosorption is considered as an ecological tool that is applied worldwide for the remediation of pollution. In this study, we proposed Lemna gibba biomass (LGB), a lignocellulosic sorbent material, for the removal of two textile dyes, Direct Red 89 (DR-89) and Reactive Green 12 (RG-12). These azo dyes commonly used in dying operations of natural and synthetic fibres are the most important pollutants produced in textile industry effluents. For this purpose, batch biosorption experiments were carried out to assess the efficacy of LGB on dye treatment by evaluating the effect of contact time, biomass dosage, and initial dye concentration. The results indicated that the bioremoval efficiency of 5 mg?L^?1 DR-89 and RG-12 reached approximately 100 % after 20 min of the exposure time; however, the maximum biosorption of 50 mg?L^?1 DR-89 and 15 mg?L^?1 RG-12 was determined to be about 60 and 47 %, respectively. Fourier transform infrared spectroscopy used to explain the sorption mechanism showed that the functional groups of carboxylic acid and hydroxyl played a major role in the retention of these pollutants on the biomass surface. The modelling results using Freundlich, Langmuir, Temkin, Elovich, and Dubini Radushkevich (D-R) isotherms demonstrated that the DR-89 biosorption process was better described with the Langmuir theory (R ²?=?0.992) while the RG-12 biosorption process fitted well by the D-R isotherm equation (R ²?=?0.988). The maximum biosorption capacity was found to be 20.0 and 115.5 mg?g^?1 for DR-89 and RG-12, respectively, showing a higher ability of duckweed biomass for the bioremoval of the green dye. The thermodynamic study showed that the dye biosorption was a spontaneous and endothermic process. The efficacy of using duckweed biomass for the bioremoval of the two dyes was limited to concentrations ≤50 mg?L^?1, indicating that L. gibba biomass may be suitable in the refining step of textile effluent treatment.     

Dynamic behaviour of Cd2+ adsorption in equilibrium batch studies by CaCO3 −-rich Corbicula fluminea shell

This work presents the structural and adsorption properties of the CaCO₃ ^?-rich Corbicula fluminea shell as a natural and economic adsorbent to remove Cd ions from aqueous solutions under batch studies. Experiments were conducted with different contact times, various initial concentrations, initial solution pH and serial biosorbent dosage to examine the dynamic characterization of the adsorption and its influence on Cd uptake capacity. The characterization of the C. fluminea shell using SEM/EDX revealed that the adsorbent surface is mostly impregnated by small particles of potentially calcium salts. The dominant Cd adsorption mechanism is strongly pH and concentration dependent. A maximum Cd removal efficiency of 96.20 % was obtained at pH 7 while the optimum adsorbent dosage was observed as 5 g/L. The Langmuir isotherm was discovered to be more suitable to represent the experimental equilibrium isotherm results with higher correlation coefficients (R ²?>?0.98) than Freundlich (R ²?<?0.97).The correlation coefficient values (p?<?0.01) indicated the superiority of the Langmuir isotherm over the Freundlich isotherm.     

Removal of mercury(II) from aqueous solutions using the leaves of the Rambai tree (Baccaurea motleyana)

This study was undertaken to evaluate the biosorption potential of a natural, low-cost biosorbent, Rambai leaves (Baccaurea motleyana), to remove trace amounts of Hg(II) from aqueous solutions. It was found that the amount of Hg(II) biosorption by Rambai leaves increased with initial metal ion concentration, contact time, and solution pH but decreased as the amount of biosorbent increased. The maximum biosorption capacity was 121.95 mg/g for an initial concentration range of 5 to 120 ppb. Overall, kinetic studies showed that the Hg(II) biosorption process followed pseudo-second-order kinetics based on pseudo-first-order and intraparticle diffusion models. Isotherm data revealed that the biosorption process followed both Freundlich and Langmuir isotherms. The value of separation factor, R(L), from the Langmuir equation and rate of biosorption, n, from the Freundlich model also indicated favorable adsorption.     

Simultaneous heavy metal removal mechanism by dead macrophytes

The use of dead, dried aquatic plants, for water removal of metals derived from industrial activities as a simple biosorbent material has been increasing in the last years. The mechanism of simultaneous metal removal (Cd2+, Ni2+, Cu2+, Zn2+ and Pb2+) by 3 macrophytes biomass (Spirodela intermedia, Lemna minor and Pistia stratiotes) was investigated. L. minor biomass presented the highest mean removal percentage and P. stratiotes the lowest for all metals tested. Pb2+ and Cd2+ were more efficiently removed by the three of them. The simultaneous metal sorption data were analysed according to Langmuir and Freundlich isotherms. Data fitted the Langmuir model only for Ni and Cd, but Freundlich isotherm for all metals tested, as it was expected. The K(F) values showed that Pb was the metal more efficiently removed from water solution. The adsorption process for the three species studied followed first order kinetics. The mechanism involved in biosorption resulted ion exchange between monovalent metals as counter ions present in the macrophytes biomass and heavy metal ions and protons taken up from water. No significant differences were observed in the metal exchange amounts while using multi-metal or individual metal solutions.     

Loofa sponge immobilized fungal biosorbent: a robust system for cadmium and other dissolved metal removal from aqueous solution

The potential of loofa sponge discs to immobilize fungal biomass of Phanerochaete chrysosporium (a known biosorbent) was investigated as a low cost biosorbent for the removal of Cd(II) ions from aqueous solution. A comparison of the biosorption of Cd(II) by immobilized and free fungal biomass from 10 to 500 mg l(-1) aqueous solutions showed an increase in uptake of over 19% when the biomass is immobilized (maximum biosorption capacity of 89 and 74 mg Cd(II) g(-1) biomass for immobilized and free biomass respectively at a solution pH of 6). Equilibrium was established within 1h and biosorption was well defined by the Langmuir isotherm model. The immobilized biomass could be regenerated using 50 mM HCl, with up to 99% metal recovery and reused in ten biosorption-desorption cycles without significant loss of capacity. This study suggests that such an immobilized biosorbent system has the potential to be used in the industrial removal/recovery of cadmium and other pollutant metal ions from aqueous solution.     

Lead biosorption and desorption by intact and pretreated spirulina maxima biomass

In order to search for locally available and untried biomaterials in China with high removal capacity of heavy metals from wastewater, the feasibility of Spirulina maxima as biosorbent for lead removal and recovery from aqueous solution was investigated. The lead biosorption was studied by using intact biomass and pretreated biomass of S. maxima. The effects of operational conditions (e.g. pH, contact time, biomass concentration etc.) on lead biosorption were investigated. The biosorption was solution pH dependent and the maximum adsorption was obtained at a solution pH of about 5.5. The adsorption equilibrium was reached in 60 min. The biosorption followed the Freundlich isotherm model. The maximum removal ratios of lead were about 84% in intact biomass and 92% in pretreated biomass. The lead adsorbed could be desorbed effectively by 0.1 M nitric acid, EDTA and hydrochloric acid. The results in this study indicated that pretreated biomass of S. maxima was a promising candidate for removing lead from wastewater.     

Biosorption of lead ion by chemically-modified biomass of marine brown algae Laminaria japonica

In this paper, marine brown algae Laminaria japonica was chemically-modified by crosslinking with epichlorohydrin (EC(1), EC(2)), or oxidizing by potassium permanganate (PC), or only washed by distilled water (DW). They were used for equilibrium sorption uptake studies with lead. As can be seen from the experimental results that biosorption equilibriums were rapidly established in about 2h. The lead adsorption was strictly pH dependent, and maximum removal of lead on biosorbents were observed at pH 5.3. The effects solid/liquid ratio on lead biosorption was also investigated. The maximum lead uptakes were 1.67 mmol g(-1), 1.62 mmol g(-1), 1.54 mmol g(-1) and 1.21 mmol g(-1), respectively for EC(1), EC(2), PC and DW. The order of maximum lead uptakes for different pretreated and raw alga was EC(1)>EC(2)>PC>DW. A comparison of different isotherm models revealed that the combination of Langmuir and Freundlich (L-F) isotherm model fitted the experimental data best.     

Biosorption properties of zinc(II) from aqueous solutions by Pseudevernia furfuracea (L.) Zopf

Pseudevernia furfuracea (L.) Zopf biosorption efficiency for zinc(II) was determined. The biosorption efficiency of Zn(II) onto P. furfuracea was significantly affected by the parameters of pH, biomass concentration, stirring speed, contact time, and temperature. The maximum biosorption efficiency of P. furfuracea was 92% at 10 mg/L Zn(II), for 5 g/L lichen biomass dosage. The biosorption of Zn(II) ions onto biomass was better described by the Langmuir model and the pseudo-second-order kinetic. The obtained thermodynamic parameters from biosorption of Zn(II) ions onto biomass were feasible, exothermic, and spontaneous. The different desorbents were used to perform the desorption studies for Zn(II)-loaded biomass. Fourier transform infrared (FTIR) spectroscopy was used to determine the participating functional groups of P. furfuracea biomass in Zn (II) biosorption. The broad and strong bands at 3292–3304 cm^?1 were due to bound hydroxyl (–OH) or amine (–NH) groups. The effective desorptions were obtained up to 96% with HNO₃. P. furfuracea is an encouraging biosorbent for Zn(II) ions, with high metal biosorption and desorption capacities, availability, and low cost. It was believed that by using this new method in which biomass is used as a sorbent, the toxic pollutants could be selectively removed from aqueous solutions to desired low levels. The remarkable properties of lichens in the transformation and detoxification of organic and inorganic pollutants are well known, and many processes have received attention in the general area of environmental biotechnology and microbiology.

Implications:The remarkable properties of lichens in the biosorption capacity of organic and inorganic pollutants are well known, and many processes have received attention in the general area of environmental biotechnology and microbiology.     

Fluoride removal studies using virgin and Ti (IV)-modified Musa paradisiaca (plantain pseudo-stem) carbons

The preparation of carbons in virgin and Ti-modified forms under controlled conditions at low temperature from plantain pseudo-stem (Musa paradisiaca) was achieved. These prepared carbons were characterized for instrumental studies such as BET, FTIR, XRD, SEM with EDS and TGA to understand the chemistry and modification. The determination of IEP and pH_ZPC established the presence of positive surface sites on the virgin (VMPC) and Ti-modified (TiMPC) carbons to facilitate the sorption of fluoride. The fluoride removal efficiency as a function of time, pH, dose, initial fluoride concentration, temperature, and co-ion intervention was studied. The maximum fluoride removal of about 81.2 and 97.7% was achievable with VMPC and TiMPC, respectively, after 20 min at the pH of 2.04 and continued for the equilibrium of 60 min. Temperature was found to be influential both by way of initial increase followed by a decrease in the fluoride uptake of MPCs. Regeneration was very consistent up to 7 cycles with the residual fluoride concentration below the WHO guide line of 1.5 mg L^?1. Highest intervention due to hydrogen carbonate ions was observed during the fluoride removal process. Kinetic (pseudo-first-order, pseudo-second-order, and intra-particle diffusion) and isotherm models (Langmuir, Freundlich, and DKR) were checked for their compliance with the present sorption system. These low temperature synthesized MPCs are found to be effective candidates in the process of fluoride abatement in water.