Dynamics and Thermodynamics Studies on the Lead and Cadmium Removal from Aqueous Solutions by Padina sp. Algae: Studies in Single and Binary Metal Systems

Raw and modified biomasses prepared from Padina sp. algae have been used as sorbent for the removal of lead and cadmium from single and binary aqueous solutions. The effects of chemical pretreatment, exposure time, initial solution pH, initial metal concentration, and temperature on the metal uptake by the algae were investigated. It was observed that initial solution pH considerably influenced Pb and Cd uptake. The maximum removal occurred at initial pH of 5.0 for lead and 6.0 for cadmium. Also, alkali modified biomass has been shown to have a high uptake capacity for both lead and cadmium. The kinetic and equilibrium experimental data fitting tested with various models. The pseudo-first-order kinetic model and Langmuir isotherm provided the best correlation of the kinetic and equilibrium experimental data, respectively. The maximum uptake estimated from the Langmuir isotherm was 264 mg g^?1 for lead and 164 mg g^?1 for cadmium ions. Experimental biosorption data in binary system were well described by the extended Langmuir model. Various thermodynamic parameters, such as ΔG°, ΔH°, and ΔS° were calculated.     

非活性藻类吸附重金属的研究

藻类对重金属有很好的吸附作用，并具有成本低，选择性好，吸附量大，浓度适用范围广等众多优点，而且带来的环境污染小，可作为一种廉价吸附剂。但目前存在机械强度低，可操作条件差等特点，限制了在实际中的应用。本文在综述和分析藻类吸附重金属研究机理基础上，着重介绍了吸附剂的改性处理方式及吸附特点和效果的分析，并探讨了进一步改性处理方式和应用前景。     

Uptake of Sulfa Drugs from Aqueous Solutions by Marine Algae

Marine algae Lessonia nigrescens Bory (L13) and Macrocystis integrifolia Bory (S12) were evaluated as adsorbents for the removal of sulfamethoxazole (SMX) and sulfacetamide (SAM). Batch adsorption of SMX and SAM was investigated as a function of pH, adsorbent dosage, initial sulfa concentration, and ionic strength. The maximum adsorption capacity of SMX followed the trend: L13 > S12 within the range 56.63-73.8 mg/g, whereas for SAM, it ranged between 177.94 and 163.67 mg/g with the trend: S12 > L13. Based on the results, the formation of hydrogen bonds as the main mechanism is proposed. A solution of 0.1 N NaOH recovered the adsorbents with a high efficiency for their use in repetitive cycles. FTIR and SEM techniques were utilized for the characterization of both adsorbents. The potential use of seaweed in the elimination of sulfas from residual water was explored as a low-cost and environmentally-friendly purification technique.     

Biosorption of Cadmium by Citrobacter sp. JH 11-2 Isolated from Mining Site Soil

The wide use of cadmium (Cd) in batteries and semiconductors poses human and environmental health hazards when these materials are disposed. Citrobacter sp. JH 11-2, isolated from soil at an abandoned mining site, shows potential for use as a biosorbent for Cd removal from aqueous solution. A minimal inhibitory concentration of 300 mg L^?1 indicated high tolerance of the strain to Cd. The strain effectively removed 47.7% of the Cd from a 100 mg L^?1 solution within 160 h. Cell fractioning revealed that most of the Cd (43.5%) was in the membrane fraction, while 38.5% was in the peptidoglycan layer and 18.0% was in the cytoplasmic fraction. Fourier transform infrared spectroscopy (FTIR) confirmed the presence of functional groups on dried Citrobacter sp. JH 11-2 cells that can adsorb or complex Cd ions. A Langmuir model provided a good fit to Cd removal by the cells, which followed pseudo-second-order kinetics. Results support further development of Citrobacter sp. JH 11-2 as a biosorbent for Cd removal.     

Biosorption of heavy metals by chemically‐activated alga Fucus vesiculosus

The sorption capacity of the brown alga Fucus vesiculosus for copper, cadmium, lead and nickel was investigated. Metal sorption yields were modified using different kinds of pretreatment reagents: HCl, CaCl₂, formaldehyde, Na₂CO₃ and NaOH. The Langmuir isotherm was applied to both the non‐treated and all treated biomass tests. Calcium chloride was the only chemical that improved the maximum sorption capacity of the biomass. Copyright © 2005 Society of Chemical Industry     

Heavy Metal Adsorption Properties of Marine Algae Durvilliea Potatorum, Ecklonia Radiata and Laminaria Japonica

1 INTRODUCTIONBiosorption of heavy metals using biosorbents derived from suitable biomass is a new tech-nology for the removal and recovery of heavy metals from industrial waste waters.The ad-vantages of the biosorption technology include rapid reduction of dissolved heavy metal ionsconcentration to 10~(-6)and 10~(-9)levels,use of inexpensive and non-hazardous biosorbents,useof existing adsorption process equipment and therefore low operating costs,high uptake ca-pacity and specificity for selective heavy metal removals,and low interference from other     

Comparison of Biosorption of Nickel (II) and Copper (II) Ions from Aqueous Solution by Sphaeroplea Algae and Acid Treated Sphaeroplea Algae

Abstract

Biosorption of nickel (II) and copper (II) ions from aqueous solution by dead sphaeroplea algae in natural and acid treated forms were studied as a function of concentration, pH, and adsorbent dose. The optimum pH for nickel (II) and copper (II) biosorption was found to be 6.0 and 4.0 respectively. The metal ion uptake increased with initial metal ion concentration studied up to 500 mg/L. Both the Freundlich and Langmuir adsorption models could fit the equilibrium data. The adsorption reasonably fitted the Lagergren kinetic model. Further the biomass was characterized by FTIR spectra. Surface area values are measured to be 0.9 and 2.1 m²/g for natural and acid treated forms respectively. The maximum adsorption capacity was found to be 3.40, 4.15 mmol/g for nickel (II) and 2.21, 3.41 mmol/g for copper (II) in natural and acid treated forms respectively.     

Biosorption Characteristics in the Mixed Heavy Metal Solution by Biosorbents of Marine Brown Algae

The biomass of nonliving, dried marine brown algaeU. pinnatifida, H. fusiformis, andS. fulvellum harvested in the sea near Cheju Island, Korea were studied for their sorption ability of copper, zinc, and lead. The metal uptakes by biosorbent materials increased with increasing initial metal concentration and pH in the range of C_i 0.0510 mM. The higher metal uptakes were obtained in the range of pHs 4.0–5.3, 4.0–6.0, and 3.0–6.0 for copper, lead, and zinc, respectively. The metal uptakes by biosorbent materials decreased in the following sequence:U. pinnatifida> H. fusiformis> S. fulvellum. The maximum metal uptake values ofU. pinnatifida for Cu²⁺, Pb²⁺, and Zn²⁺ in the single metal solution are 2.58, 2.6, and 2.08 meq/g in the range of pHs 5.3–4.4, respectively. The metal uptakes by biosorbent materials in the mixed metal solution decreased greatly in comparison to each metal uptake in the single metal solution.     

Quantifying in Situ Rates of Phlorotannin Synthesis and Polymerization in Marine Brown Algae

Using three species of marine brown algae, we describe a stable isotope labeling technique to quantify: (1) in situ rates of phlorotannin synthesis, (2) phlorotannin polymerization or aging, and (3) the related allocation of carbon resources to secondary metabolism. In our field and laboratory assays, Lobophora variegata (Bahamas), Sargassum pteropleuron (Bahamas), and Fucus distichus (California, USA) assimilated various quantities of ¹³C, but all allocated 1% of the assimilated carbon to the production of phlorotannins. We quantified rates of phlorotannin synthesis both as micrograms of compound produced per gram of tissue per unit of time and as micrograms of compound produced per gram of C assimilated per unit of time. Rates of synthesis, normalized to account for differences in potential photosynthetic rates, are comparable to previously reported rates of phlorotannin accumulation. The aging of phlorotannins from low- (<30 kDa) to high- (>30 kDa) molecular-size polymers was observed in S. pteropleuron within a 28-hr period. Our results indicate that, using this labeling technique, it is possible to make precise measurements of allelochemical metabolism and resource allocation, which are useful both in critically evaluating the assumptions made by ecological models of plant chemistry and in estimating the partial metabolic cost of specific secondary metabolites.     

Biosorption of a Basic Dye from Aqueous Solutions by Euphorbia rigida

Abstract

In this study, the biosorption of Basic Blue 9 (BB9) dye from aqueous solutions onto a biomass of Euphorbia rigida was examined by means of the initial biosorbate concentration, biosorbent amount, particle size, and pH. Biosorption of BB9 onto E. rigida increases with both the initial biosorbate concentration and biosorbent amount, whereas decreases with the increasing particle size. The experimental data indicated that the biosorption isotherms are well‐described by the Langmuir equilibrium isotherm equation at 20, 30, and 40°C. Maximum biosorption capacity was 3.28×10^?4 mol g^?1 at 40°C. The biosorption kinetics of BB9 obeys the pseudo‐second‐order kinetic model. The thermodynamic parameters such as ΔG°, ΔH° and ΔS° were calculated to estimate the nature of biosorption. These experimental results have indicated that E. rigida has the potential to act as a biosorbent for the removal of Basic Blue 9 from aqueous solutions.     

Equilibrium,Thermodynamic and Kinetic Studies on Biosorption of Mercury from Aqueous Solution by Macrofungus (Lycoperdon perlatum) Biomass

The present research is to investigate the possibility of macrofungus Lycoperdon perlatum biomass, which is an easily available, renewable plant, low-cost, as a new biomass for the removal of mercury (Hg(II)) ions from aqueous solutions. The effects of various parameters like pH of solution, biomass concentration, contact time, and temperature were studied by the using the batch method. The Langmuir model adequately described the equilibrium data. The biosorption capacity of the biomass was found to be 107.4 mg · g^?1 at pH 6. The mean free energy value (10.9 kJ · mol^?1) obtained from the D–R model indicated that the biosorption of Hg(II) onto fungal biomass was taken place via chemical ion-exchange. Thermodynamic parameters showed that the biosorption of Hg(II) onto L. perlatum biomass was feasible, spontaneous, and exothermic in nature. The kinetic results showed that the biosorption of Hg(II) onto fungal biomass followed second-order kinetics. This work also shows that L. perlatum biomass can be an alternative to the expensive materials like ion exchange resins and activated carbon for the treatment of water and wastewater containing mercury ions due to its ability of selectivity and higher biosorption capacity and also being low cost material.     

Biosorption of Reactive Yellow 145 Dye by Dried Penicillum restrictum: Isotherm,Kinetic, and Thermodynamic Studies

Removal of dyes from wastewaters causes a big concern from the environmental point of view due to their extreme toxicity towards aquatic life and humans. Commonly used traditional methods to treat these effluents are ineffective because dyes show resistance to many chemicals, oxidizing agents, and light. In this context, the biosorption process has attracted great attention in recent years since they utilize not only cheap plant materials but also a wide variety of microorganisms as biosorbing agents, displaying a high dye-binding capacity. In this study, biosorption potential of dried Penicillum restrictum (DPR) for Reactive Yellow 145 (RY 145) was studied with respect to pH, equilibrium time, and temperature to determine equilibrium and kinetic models. The most suitable pH and equilibrium time were determined as 1.0 ± 0.05 and 75 min respectively, at a biomass dosage of 0.4 mg L^?1 and 20 ± 0.5°C. Data obtained from batch studies fitted well with the Dubinin-Radushkevich (D-R) followed by the Freundlich and Langmuir isotherm models. Maximum uptake capacities (qm) of DPR for the dyestuff (RY 145) were 109.7, 115.2, and 116.5 mg g^?1 biomass at temperatures of 20, 30, and 40 ± 0.5°C, respectively. The overall biosorption process was best described by the pseudo-second-order kinetic model. Gibbs free energy changes were calculated as ?384.6, ?273.5, and ?245.9 J mol L^?1 at 20, 30, and 40 ± 0.5°C, respectively.     

Equilibrium,Kinetic, and Thermodynamic Studies on the Biosorption of Selenium (IV) Ions onto Ganoderma Lucidum Biomass

The capacity of Ganoderma lucidum biomass for biosorption of selenium (IV) ions from aqueous solution was studied in a batch mode. In this study the effects of operating parameters such as solution pH, adsorbent dosage, initial metal concentration, contact time, and temperature were investigated. The adsorption capacity of G. lucidum was found to be 126.99 mg g^?1. The biosorption follows pseudo-first order kinetics and the isotherms fit well to both Langmuir and Freundlich isotherm models. Isotherms have been used to determine thermodynamic parameters of the process, that is, free energy, enthalpy, and entropy changes. Furthermore, the biosorbent was characterized by scanning electron microscopy and FT-IR analysis. FT-IR analysis of fungal biomass shows the presence of amino, carboxyl, hydroxyl, and carbonyl groups, which were responsible for the biosorption of selenium(IV) ions. The results indicated that the biomass of G. lucidum is an efficient biosorbent for the removal of selenium (IV) ions from aqueous solutions.     

Biosorption of As(III) Ion on Rhodococcus sp. WB-12: Biomass Characterization and Kinetic Studies

Biomass obtained from arsenic resistant gram positive bacteria Rhodococcus sp. WB-12 was studied for the removal of arsenite from aqueous solution. The biomass sorption characteristic was investigated as a function of biomass doses, contact time, and pH. The Langmiur Freundlich, and Dubinin-Radushkevich (D-R) models were applied to describe the biosorption isotherm. The biosorption capacity of the biomass for As(III) was found to be 77.3 mg/g (pH 7.0) using 1 g/L biomass with the contact time of 30 min at 30°C. Kinetic evaluation of experimental data showed biosorption of As (III) followed pseudo-second-order kinetics. The Fourier transform infrared spectroscopy (FT-IR) analysis indicated the involvement of possible functional groups (-OH, -C=O, -NH) in the arsenite biosorption process. Thus, biomass derived from Rhodococcus sp. WB-12 cells has potential for use as biosorbent for the removal of arsenic from contaminated water.     

Biosorption of mercury and lead by aqueous Streptomyces VITSVK9 sp. isolated from marine sediments from the bay of Bengal,India

Toxic heavy metals are increasingly accumulating in the environment worldwide and are considered to be life threatening contaminants. The biosorption of mercury and lead by marine actinomycetes isolated from marine sediment collected from the Bay of Bengal coast of Puducherry, India, was evaluated. The maximum tolerance concentration (MTC) of Streptomyces sp. was determined by a well diffusion method and a broth dilution method. The effects of the initial metal ion concentration, the pH and the biomass dosage on the biosorption of mercury and lead ions were investigated. The MTC of the isolate to metals was 200 mg·L^-1 for mercury and 1800 mg·L^-1 for lead. At neutral pH, the isolate had a maximum biosorption of metal ions of 200 mg·L^-1 and 150 mg·L^-1 for mercury and lead respectively. Fourier transform infrared (FTIR) absorption spectra showed the chemical interactions between the functional groups in the biomass such as hydroxyl (-OH), amine (-NH₂), carboxyl (-COOH) and the metal ions. The isolate was further characterized by molecular taxonomy and identified as a member of the genus Streptomyces. Based on the phenotypic and phylogenetic analysis, the strain was classified as a new species of the genus Streptomyces and designated as Streptomyces VITSVK9 sp. (HM137310). A blast search of the 16S rDNA sequence of the strain showed the most similarity (95%) with Streptomyces sp. A515 Ydz-FQ (EU384279). Based on the results, it can be concluded that this marine Streptomyces could be used as a biosorbent for the removal of heavy metal ions from aqueous environments.     

Biosorption of heavy metals (Cd,Cu, Ni,Pb, Zn) by chemically-reinforced biomass of marine algae

Particles of two different sizes (0·105–0·295 mm and 0·84–1.00 mm diameter) of two marine algae, Sargassum fluitans and Ascophyllum nodosum, were crosslinked with formaldehyde (FA), glutaraldehyde (GA) or embedded in polyethylene imine (PEI), followed by glutaraldehyde crosslinking. They were used for equilibrium sorption uptake studies with cadmium, copper, nickel, lead and zinc. The metal uptake by larger particles (0·84–1·00 mm) was higher than that by smaller particles (0·105–0·295 mm). The order of adsorption for S. fluitans biomass particles was Pb > Cd > Cu > Ni > Zn, for A. nodosum copper and cadmium change places. Uptakes of metals range from q_max = 378 mg Pb g^?1 for S. fluitans (FA, big particles), to q_max = 89 mg Zn g^?1 for S. fluitans (FA, small particles) as the best sorption performance for each metal. Generally, S. fluitans is a better sorbent material for a given metal, size and modification, although there were several exceptions in which metal sorption by A. nodosum was higher. The metal uptake for different chemical modifications showed the order GA > FA > PEI. A comparison of different sorption models revealed that the Langmuir sorption model fitted the experimental data best.