Personal Research Database

Full Text: 2005\Wat Res39, 3287.pdf

Abstract: Natural zeolites, known for their excellent sorption properties towards metal cations, are widely used for the purification of wastewaters. The selectivity of clinoptilolite, a common zeolite mineral, for Pb is known to be particularly high, whereas its selectivity for Cd is often lower. Extraordinarily high sorption capacities for soft metal cations were observed in the case of thiol-functionalized silica gels and clays. In order to enhance the zeolites’ sorption capacity for Cd, we treated natural heteroionic and Na-clinoptilolite in aqueous suspensions with cysteamine and propylamine solutions and investigated the sorption of Cd and Pb to amine-modified zeolite by a series of batch experiments. Stability constants for amine sorption on all zeolite samples at room temperature and 50 °C were obtained. Partial dimerization of cysteamine explains the enhanced sorption of this compound.

In contrast, amine treatment did not enhance the adsorption capacity or selectivity of the clinoptilolite towards Cd and Pb. Instead, the amounts of adsorbed heavy metals decreased stoichometrically with increasing sorption of cysteamine and propylamine. This reduction can be explained by the blockage of channels by amine molecules and revealed that the modification of zeolites with mercaptoamines does not enhance the sorption capacity of zeolite for Cd and Pb.

Keywords: Zeolite, Sorption, Mercaptoamines, Heavy Metals, Dimerization

? Zhou, D., Zhang, L.N. and Guo, S.L. (2005), Mechanisms of lead biosorption on cellulose/chitin beads. Water Research, 39 (16), 3755-3762.

Full Text: 2005\Wat Res39, 3755.pdf

Abstract: Environment-friendly cellulose/chitin beads being prepared by coagulating a blend of cellulose and chitin in 6 wt% NaOH/5 wt% thiourea aqueous solution with 5% H₂SO₄ possessed higher heavy metals uptake capacity than pure chitin flakes. The mechanisms of Pb²⁺ adsorption on cellulose/chitin beads at pH₀=5 were investigated at the molecular levels by scanning electron micrographs (SEM), transmission electron micrographs (TEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffraction (XRD). The result revealed that mechanisms for the adsorption of Pb²⁺ on the cellulose/chitin beads could be described as complexation between Pb²⁺ and N atom in the chitin, and further adsorption of Pb²⁺ nearby the complexed Pb²⁺ and precipitation of the hydrolysis product of the Pb²⁺ complex on the beads as the crystalline state. Furthermore, structural factors such as larger surface area of the beads resulted from microporous-network structure, low crystallinity of cellulose/chitin beads and high hydrophilicity induced by hydrophilic skeleton of cellulose played an important role in increasing adsorption ability.

Keywords: Cellulose, Chitin, Beads, Heavy Metal, Adsorption, Mechanism

? Jeon, C. and Park, K.H. (2005), Adsorption and desorption characteristics of mercury(II) ions using aminated chitosan bead. Water Research, 39 (16), 3938-3944.

Full Text: 2005\Wat Res39, 3938.pdf

Abstract: Adsorption and desorption characteristics for mercury ions using aminated chitosan bead which showed very high affinity to mercury ions were studied. The adsorption of mercury ions using aminated chitosan bead was an exothermic process since binding strength each other increased as the temperature decreased. And the adsorption of mercury ions was almost completed in 100 min at 150 rpm. In case that adsorbent dose increased, mercury uptake capacity decreased, while, removal efficiency increased. The beads were not greatly affected by the ionic strength, organic material and alkaline-earth metal ions. Mercury ions adsorbed on aminated chitosan bead were desorbed effectively about 95% by EDTA and the adsorption capacity of the recycled beads can still be maintained at 90% level at the 5th cycle.

Keywords: Chitosan, Mercury Ions, Biosorption, Polysaccharides, Adsorption, Desorption

? Zhang, Y.P. and Zhou, J.L. (2005), Removal of estrone and 17β-estradiol from water by adsorption. Water Research, 39 (16), 3991-4003.

Full Text: 2005\Wat Res39, 3991.pdf

Abstract: Endocrine disrupting chemicals (EDCs) are the focus of current environment concern, as they can cause adverse health effects in an intact organism, or its progeny, subsequent to endocrine function. The paper reports on the removal of estrone (E1) and 17β-estradiol (E2) from water through the use of various adsorbents including granular activated carbon (GAC), chitin, chitosan, ion exchange resin and a carbonaceous adsorbent prepared from industrial waste. The results show that the kinetics of adsorption were adsorbent and compound-dependent, with equilibration being reached within 2 h for a waste-derived carbonaceous adsorbent to 71 h for an ion-exchange resin for E1, and within 7 h for the waste-derived carbonaceous adsorbent to 125 h for GAC for E2. Of all the adsorbents tested, the carbonaceous adsorbent showed the highest adsorption capacity, with a maximum adsorption constant of 87500 ml/g for E1 and 116000 ml/g for E2. The GAC also had a very high adsorption capacity for the two compounds, with a maximum adsorption constant of 9290 ml/g for E1 and 12200 ml/g for E2. The effects of some fundamental environmental parameters including adsorbent concentration, pH, salinity and the presence of humic acid and surfactant on adsorption were studied. The results show that adsorption capacity of activated carbon was decreased with an increase in adsorbent concentration and by the presence of surfactant and humic acid. The results have demonstrated excellent performance of a waste derived adsorbent in removing E1 and E2 from water, and indicated the potential of converting certain solid waste into useful adsorbents for pollution-control purposes.

Keywords: Endocrine Disrupting Chemicals, Adsorption, Activated Carbon, Carbonaceous Adsorbent, Wastewater

? Parette, R. and Cannon, F.S. (2005), The removal of perchlorate from groundwater by activated carbon tailored with cationic surfactants. Water Research, 39 (16), 4020-4028.

Full Text: 2005\Wat Res39, 4020.pdf

Abstract: In rapid small-scale column tests, cationic surfactant-tailored activated carbons (ACs) effectively removed perchlorate to below detection levels for up to 30 times longer than virgin AC. By pre-loading bituminous AC with dicocodimethylammonium chloride, tallowtrimethylammonium chloride, cetyltrimethylammonium chloride, or cetylpyridinium chloride, 75 ppb perchlorate was removed for 27,000–35,000 bed volumes before the effluent perchlorate rose above 1 ppb. These tests employed a natural groundwater that also contained 30 mg/L sulfate, 26 mg/L nitrate (as NO₃⁻), and other ions. By the time of 25 ppb perchlorate breakthrough, 7.3–10.1% of quaternary ammonium sites had perchlorate associated with them. Although some of the surfactants leached out of the tailored carbon beds (0.6–21.2% of the amount loaded), the leached surfactant could be removed to below detectable limits with a virgin AC polishing bed that chased the tailored bed.

Keywords: Perchlorate, Granular Activated Carbon (GAC), Cationic surfactant; Rapid Small-Scale Column Test (RSSCT)

? Lau, S.L. and Stenstrom, M.K. (2005), Metals and PAHs adsorbed to street particles. Water Research, 39 (17), 4083-4092.

Full Text: 2005\Wat Res39, 4083.pdf

Abstract: Particles were collected from 18 different city streets adjacent to five different landuses in the City of Santa Monica, California. Landuses were classified as industrial, roads, multifamily residential, commercial and single family residential. Particles were collected using a vacuum cleaner with a 0.1-μm filter and a rotating brush head. Particles were first sized into six fractions from 43–2200 μm using two sets of sieves. Representative samples of the four size fractions smaller than 841 μm from each landuse were separately digested to extract metals and polynuclear aromatic hydrocarbons (PAHs). Smaller particles had higher solid-phase concentrations, but not as high as the ratios of their specific surface areas, assuming spherical shape. Relative PAHs concentrations were higher on small particles than were metal concentrations. Single-family residential areas were the lowest in metals and PAHs, with only a few exceptions. The greatest mass of pollutants was associated with the particles in the 100–250 μm range.

Keywords: Stormwater, Heavy Metals, PAHs, Street, Particles

? Figueiredo, S.A., Loureiro, J.M. and Boaventura, R.A. (2005), Natural waste materials containing chitin as adsorbents for textile dyestuffs: Batch and continuous studies. Water Research, 39 (17), 4142-4152.

Full Text: 2005\Wat Res39, 4142.pdf

Abstract: In this work three natural waste materials containing chitin were used as adsorbents for textile dyestuffs, namely the Anodonta (Anodonta cygnea) shell, the Sepia (Sepia officinalis) and the Squid (Loligo vulgaris) pens. The selected dyestuffs were the Cibacron green T3G-E (CI reactive green 12), and the Solophenyl green BLE 155% (CI direct green 26), both from CIBA, commonly used in cellulosic fibres dyeing, the most used fibres in the textile industry.

Batch equilibrium studies showed that the materials’ adsorption capacities increase after a simple and inexpensive chemical treatment, which increases their porosity and chitin relative content. Kinetic studies suggested the existence of a high internal resistance in both systems. Fixed bed column experiments performed showed an improvement in adsorbents’ behaviour after chemical treatment. However, in the column experiments, the biodegradation was the main mechanism of dyestuff removal, allowing the materials’ bioregeneration. The adsorption was strongly reduced by the pore clogging effect of the biomass.

The deproteinised Squid pen (grain size 0.500–1.41 mm) is the adsorbent with highest adsorption capacity (0.27 and 0.037 g/g, respectively, for the reactive and direct dyestuffs, at 20 °C), followed by the demineralised Sepia pen and Anodonta shell, behaving like pure chitin in all experiments, but showing inferior performances than the granular activated carbon tested in the column experiments.

Keywords: Acid Dye, Activated Carbon, Adsorption, Adsorption, Basic-Dyes, Carbon, Chitin, Chitosan Fibers, Color, Dye Removal, Dyestuffs, Epichlorohydrin-Cellulose Polymer, Low-Cost Adsorbents, Removal, Textile Wastewaters

? Rangsivek, R.and Jekel, M.R. (2005), Removal of dissolved metals by zero-valent iron (ZVI): Kinetics, equilibria, processes and implications for stormwater runoff treatment. Water Research, 39 (17), 4153-4163.

Full Text: 2005\Wat Res39, 4153.pdf

Abstract: Infiltration of stormwater runoff contaminated with metals is often questionable in several cases due to its long-term potential to cause deterioration of groundwater quality. To ensure the quality of filtrate, a pre-treatment of contaminated runoff is required. This study investigates the processes of copper and zinc ion removal from stormwater runoff using zero-valent iron (ZVI, Fe⁰). Kinetic and equilibrium tests were performed with laboratory-prepared and in situ stormwater runoff samples collected from roof, street and highway catchments. Based on the results, a substantial portion of Cu²⁺ is reduced and transformed to insoluble forms of Cu⁰ and Cu₂O. Unlike copper, the adsorption and co-precipitation associated with freshly precipitated iron oxides play important roles for the removal of Zn²⁺. Investigations under various water quality conditions demonstrated a relatively minor impact on Cu²⁺ uptake rates. However, the different conditions apparently altered the removal stoichiometry and phases of the copper deposits. The removal rates of Zn²⁺ increase with higher dissolved oxygen (DO), ionic strength (IS), temperature (T) and pH. Dissolved organic carbon (DOC) in runoff samples forms complexes with metals and Fe²⁺, thereby kinetically decreasing the metal uptake rates. Furthermore, depending on its composition, a larger molecular weight organic fraction was found to preferentially compete for the adsorption sites. The study demonstrates that ZVI is a promising medium for achieving comparable capacity to a commercial adsorbent like granular ferric hydroxide (GFH). Long-term performance of ZVI, however, may be limited and governed by the formation of non-conductive layers of iron and cuprous oxides.

Keywords: Adsorption, Cementation, Heavy Metals, Iron Corrosion, Runoff Pollutants, Zero-Valent Iron (ZVI)

? Bi, E., Haderlein, S.B. and Schmidt, T.C. (2005), Sorption of methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) to synthetic resins. Water Research, 39 (17), 4164-4176.

Full Text: 2005\Wat Res39, 4164.pdf

Abstract: Methyl tert-butyl ether (MTBE) is a widely used gasoline oxygenate. Contamination of MTBE and its major degradation product tert-butyl alcohol (TBA) in groundwater and surface water has received great attention. However, sorption affinity and sorption mechanisms of MTBE and TBA to synthetic resins, which can be potentially used in removal of these contaminants from water, in passive sampling, or in enrichment of bacteria, have not been studied systemically. In this study, kinetic and equilibrium sorption experiments (single solute and binary mixtures) on four synthetic resins were conducted. The sorption affinity of the investigated sorbents for MTBE and TBA decreases in the order Ambersorb 563>Optipore L493>Amberlite XAD4>Amberlite XAD7, and all show higher sorption affinity for MTBE than for TBA. Binary experiments with o-xylene, a major compound of gasoline as co-contaminant, imply that all resins preferentially sorb o-xylene over MTBE or TBA, i.e., there is sorption competition. In the equilibrium aqueous concentration (C_eq) range (0.1–139.0 mg/L for MTBE, and 0.01–48.4 mg/L for TBA), experimental and modeling results as well as sorbent characteristics indicate that micropore filling and/or some other type of adsorption process (e.g., adsorption to specific sites of high sorption potential at low concentrations) rather than partitioning were the dominant sorption mechanisms. Optipore L493 has favourable sorption and desorption characteristics, and is a suitable sorbent, e.g., in bacteria enrichment or passive sampling for moderately polar compounds. However, for highly polar compounds such as TBA, Ambersorb 563 might be a better choice, especially in water treatment.

Keywords: MTBE, TBA, Synthetic Resins, Adsorption, Optipore L493, Sorption Kinetics

? Ogata, T. and Nakano, Y. (2005), Mechanisms of gold recovery from aqueous solutions using a novel tannin gel adsorbent synthesized from natural condensed tannin. Water Research, 39 (18), 4281-4286.

Full Text: 2005\Wat Res39, 4281.pdf

Abstract: We report a novel recovery system for gold (Au), which is one of the precious metals contained in electronic scrap, utilizing tannin gel particles. Tannin gel particles were prepared by a process of cross-linking of condensed tannin (wattle tannin), which is a ubiquitous and inexpensive natural material having many hydroxyl groups. The adsorption mechanism of gold onto tannin gel particles was elucidated: the adsorption of gold takes place through the reduction of trivalent gold ions to metallic gold on the surface of tannin gel particles, which is accompanied by the simultaneous oxidization of the hydroxyl groups of tannin gel. Additionally, the adsorption capacity of gold was found to be extremely high, 8000 mg-Au/g-dry gel. The outstanding characteristics of tannin gel particles for gold offers the possibility of efficient recovery of other precious metals. (c) 2005 Elsevier Ltd. All rights reserved.

Keywords: Tannin, Gel, Recovery, Gold, Redox, Biosorption, Hexavalent Chromium, Solvent-Extraction, Gold(III), Accumulation, Temperature, Biosorption, Reduction, Removal, Au(III), Resins

? Dunne, E.J., Culleton, N., O’Donovan, G., Harrington, R. and Daly, K. (2005), Phosphorus retention and sorption by constructed wetland soils in Southeast Ireland. Water Research, 39 (18), 4355-4362.

Full Text: 2005\Wat Res39, 4355.pdf

Abstract: It may be necessary to use constructed wetlands as a land use practice to mitigate phosphorus (P) loss from agriculture in Ireland. The objectives of this study were to determine the ability of two constructed wetland site soils to retain and sorb P. Intact soil/water column studies were used to determine P release/retention rates during a 30-day incubation period. Soil columns flooded with distilled water released P during the first 2 days; however, soluble reactive P (SRP) concentrations in overlying floodwaters decreased thereafter. Soils with overlying floodwaters spiked at 5 and 15 mg SRP L^-1 retained highest amounts of P (p < 0.05) with retention at these concentrations controlled by SRP in overlying waters. Retention rates by soils ranged between 0.3 and 60.9 mg P m^-2 d^-1. Maximum P sorption capacity (S-max) was higher for wetland soils at Dunhill, Waterford (1464 mg P kg^-1) in comparison to soils at Johnstown Castle, Wexford (618 mg P kg^-1). Equilibrium P concentrations (EPC0) were low (in the g SRP L^-1 range), indicating a high capacity of these soils to sorb P. Phosphorus sorption parameters were significantly related to ammonium oxalate extractable aluminium (Al) and iron (Fe) content of soils. (c) 2005 Elsevier Ltd. All rights reserved.

Keywords: Phosphorus, Constructed Wetlands, Agriculture, Retention, Sorption, Column Study, Fresh-Water Wetlands, Phosphate Sorption, Waste-Water, Sediments, Streams, Capacity, Dynamics, Disposal, Nitrogen, Surface

? Lazaridis, N.K. and Charalambous, C. (2005), Sorptive removal of trivalent and hexavalent chromium from binary aqueous solutions by composite alginate-goethite beads. Water Research, 39 (18), 4385-4396.

Full Text: 2005\Wat Res39, 4385.pdf

Abstract: In this study, the removal of hexavalent and trivalent chromium ions from binary aqueous solutions by composite alginate-goethite beads was investigated in a batch mode. Equilibrium sorption experiments were carried out at different temperatures and pH values. The data were correlated with Langmuir and Freundlich equations. The thermodynamic parameters calculated were: change in free energy, in enthalpy, in entropy and the heat of adsorption. The influence of mixing rate, sorbent concentration and sorbent particle size was studied at kinetic runs. The effective diffusion coefficients were evaluated by employing the homogeneous diffusion model and the shrinking core model for hexavalent and trivalent chromium, respectively. Desorption experiments were conducted by employing various eluants showed that the loaded material could be regenerated satisfactorily. (c) 2005 Elsevier Ltd. All rights reserved.

Keywords: Activated Carbon, Adsorption, Biosorbent, Biosorption, Chromate, Chromium, Desorption, Diffusion, Energy, Equilibrium, Groundwater, Hexavalent Chromium, Homogeneous Kinetic Model, Ions, Isotherms, Kinetics, Kinetics, Mg-Al-CO3 Hydrotalcite, Model, pH, Removal, Shrinking Core Model, Sorbent, Sorption, Thermodynamic Parameters, Trivalent Chromium, Waste-Water

? Hu, J., Chen, G.H. and Lo, I.M.C. (2005), Removal and recovery of Cr(VI) from wastewater by maghemite nanoparticles. Water Research, 39 (18), 4528-4536.

Full Text: 2005\Wat Res39, 4528.pdf

Abstract: Hexavalent chromium existing in the effluent is a major concern for the metal-processing plant. In this study, a new method combining nanoparticle adsorption and magnetic separation was developed for the removal and recovery of Cr(VI) from wastewater. The nanoscale maghemite was synthesized, characterized, and evaluated as adsorbents of Cr(VI). Various factors influencing the adsorption of Cr(VI), e.g., pH, temperature, initial concentration, and coexisting common ions were studied. Adsorption reached equilibrium within 15 min and was independent of initial Cr concentration. The maximum adsorption occurred at pH 2.5. The adsorption data were analyzed and fitted well by Freundlich isotherm. Cr(VI) adsorption capacity of maghemite nanoparticles was compared favorably with other adsorbents like activated carbon and clay. Competition from common coexisting ions such as Na⁺, Ca²⁺, Mg²⁺, Cu²⁺, Ni²⁺, NO₃⁻, and Cl⁻ was ignorable, which illustrated the selective adsorption of Cr(VI) from wastewater. Regeneration studies verified that the maghemite nanoparticles, which underwent six successive adsorption–desorption processes, still retained the original metal removal capacity. In addition, the adsorption mechanisms were investigated using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopic techniques.

Keywords: Adsorption, Chromium, Common Ion Effect, Desorption, Freundlich Isotherm

? Lagarde, F., Tusseau-Vuillemin, M.H., Lessard, P., Héduit, A., Dutrop, F. and Mouchel, J.M. (2005), Variability estimation of urban wastewater biodegradable fractions by respirometry. Water Research, 39 (19), 4768-4778.

Full Text: 2005\Wat Res39, 4768.pdf

Abstract: This paper presents a methodology for assessing the variability of biodegradable chemical oxygen demand (COD) fractions in urban wastewaters. Thirteen raw wastewater samples from combined and separate sewers feeding the same plant were characterised, and two optimisation procedures were applied in order to evaluate the variability in biodegradable fractions and related kinetic parameters. Through an overall optimisation on all the samples. a unique kinetic parameter set was obtained with a three-substrate model including an adsorption stage, This method required powerful numerical treatment, but improved the identifiability problem compared to the usual sample-to-sample optimisation. The results showed that the fractionation of samples collected in the combined sewer was much more variable (standard deviation of 70% of the mean values) than the fractionation of the separate sewer samples. and the slowly biodegradable COD fraction was the most significant fraction (45% of the total COD on average), Because these samples were collected under various rain conditions, the standard deviations obtained here on the combined sewer biodegradable fractions could be used as a first estimation of the variability of this type of sewer system, (c) 2005 Elsevier Ltd. All rights reserved.

Keywords: Activated-Sludge, Adsorption, Biodegradability, Biomass, Cod, Cod Fractions, France, Methodology, Model, Oxygen, Parameters, Plant, Respirometry, Seine River, Treatment, Urban, Variability, Wastewater, Wastewaters

Notes: highly cited

? Clara, M., Strenn, B., Gans, O., Martinez, E., Kreuzinger, N. and Kroiss, H. (2005), Removal of selected pharmaceuticals, fragrances and endocrine disrupting compounds in a membrane bioreactor and conventional wastewater treatment plants. Water Research, 39 (19), 4797-4807.

Full Text: 2005\Wat Res39, 4797.pdf

Abstract: Eight pharmaceuticals, two polycyclic musk fragrances and nine endocrine disrupting chemicals were analysed in several waste water treatment plants (WWTPs). A membrane bioreactor in pilot scale was operated at different solid retention times (SRTs) and the results obtained are compared to conventional activated sludge plants (CASP) operated at different SRTs. The SRT is an important design parameter and its impact on achievable treatment efficiencies was evaluated. Different behaviours were observed for the different investigated compounds. Some compounds as the antiepileptic drug carbamazepine were not removed in any of the sampled treatment facilities and effluent concentrations in the range of influent concentrations were measured. Other compounds as bisphenol-A. the analgesic ibuprofen or the lipid regulator bezafibrate were nearly completely removed (removal rates >90%). The operation of WWTPs with SRTs suitable for nitrogen removal (SRT > 10 days at 10 degrees C) also increases the removal potential regarding selected micropollutants. No differences in treatment efficiencies were detected between the two treatment techniques. As in conventional WWTP also the removal potential of MBRs depends on the SRT. Ultrafiltration membranes do not allow any additional detention of the investigated substances due to size exclusion. However, MBRs achieve a high SRT within a compact reactor. Nonylphenolpolyehtoxylates were removed in higher extend in very low-loaded conventional WWTPs, due to variations of redox conditions, necessary for the degradation of those compounds. (c) 2005 Elsevier Ltd. All rights reserved.

Keywords: Wastewater Treatment, Endocrine Disrupting Chemicals, Pharmaceuticals, Musk Fragrances, Membrane Bioreactor, Removal Efficiency, Aquatic Environment, Sewage-Treatment, Bisphenol-A, Fate, Behavior, Sludge, Parameter, Macrolide, Residues

Notes: highly cited

? Min, B., Kim, J.R., Oh, S.E., Regan, J.M. and Logan, B.E. (2005), Electricity generation from swine wastewater using microbial fuel cells. Water Research,