Personal Research Database

Full Text: J\J Env Sci Hea Par A-Tox Haz Sub Env Eng36, 1845.pdf

Abstract: Column studies were performed to determine the effect of bed height, linear flow rate, adsorbent particle size and initial metal icon concentration on lead removal by keramzite sand coated with electroplating sludge. The Bed depth service time (BDST) model applied to the data at 2% breakthrough gave the best approximation to the experimental results compared with other investigated breakthrough points. The adsorption performance of the thermally modified coated keramzite columns could be well described by the Wolborska model up to 50% breakthrough point. The application of this model allowed determination of the kinetic coefficients of external mass transfer in the fixed bed and the time for protective action of the sorbent layers. The experimental results support the assumption that the external mass transfer of the solute through the hydrodynamic boundary layer is the rate-limiting step. It has been established that the keramzite sand coated with electroplating sludge (particle size 0.5-0.8mm) can be successfully used for lead removal from dilute metal ion solutions at linear flow rate 4-6 cm/min and empty bed contact time greater than or equal to 3 min.

Keywords: Adsorption, Coated Keramzite, Electroplating Sludge, Fixed Bed, Lead Ions, Metal-Bearing Wastes, Activated-Carbon, Aqueous-Solution, Sorption, Filtration, Adsorption, Hydroxide, Adsorbent, Time, Bed

Aoyama, M., Seki, K. and Doi, S. (2001), Mercury adsorption onto pyrolyzed waste paper. Journal of Environmental Science and Health Part A-Toxic/Hazardous Substances & Environmental Engineering, 36 (10), 2047-2054.

Full Text: J\J Env Sci Hea Par A-Tox Haz Sub Env Eng36, 2047.pdf

Abstract: The ability of pyrolyzed waste paper to remove mercury from aqueous solutions by physicochemical adsorption was investigated. Defibered waste newsprint was pyrolyzed in a nitrogen atmosphere at 300 degreesC for 3 h. The pyrolysis residue showed high affinity to inorganic divalent mercury species. To investigate the adsorption characteristics, the factors affecting mercury adsorption were examined. The adsorbent was efficient in capturing mercury in neutral and basic media, although limited adsorption occurred in acidic media. The extent of the adsorption was also dependent upon the solution temperature and initial concentration of mercury in solution. The adsorption followed both the Langmuir and Freundlich isotherms.

Keywords: Waste Paper, Pyrolysis, Adsorption, Mercury, Wastewater Treatment, Aqueous-Solutions, Activated Carbon, Removal, Water, Binding, Acid, Ions

Panayotova, M. and Velikov, B. (2002), Kinetics of heavy metal ions removal by use of natural zeolite. Journal of Environmental Science and Health Part A-Toxic/Hazardous Substances & Environmental Engineering, 37 (2), 139-147.

Full Text: J\J Env Sci Hea Par A-Tox Haz Sub Env Eng37, 139.pdf

Abstract: Kinetics of the uptake of cadmium, lead, copper, nickel and zinc ions from single ion solutions and from their mixture by zeolitic rock has been studied. Removal of ions obeyed the kinetic equation for adsorption. Corresponding adsorption constants and distribution coefficients were determined for each metal ion uptake from single ion solution or mixture. An attempt was made to explain zeolite selectivity to different metal ions and the influence of water hardness on the uptake in terms of metal ionic radii and enthalpy of hydration. It was found that lead ions were strongly immobilized by the zeolite investigated, both from single ion and mixed solutions, as well as from soft and hard water.

Keywords: Heavy Metals, Wastewater Treatment, Natural Zeolite, Adsorption

Annadurai, G., Juang, R.S. and Lee, D.J. (2002), Factor optimization for phenol removal using activated carbon immobilized with Pseudomonas putida. Journal of Environmental Science and Health Part A-Toxic/Hazardous Substances & Environmental Engineering, 37 (2), 149-161.

Full Text: J\J Env Sci Hea Par A-Tox Haz Sub Env Eng37, 149.pdf

Abstract: Removal efficiency of phenol from aqueous solutions was measured using a suspended culture of Pseudomonas putida (ATCC 3180) or the activated carbon on which the microorganisms were immobilized. Experiments were performed as a function of pH (7-9), temperature (30-36 degreesC), and concentrations of glucose (0.5-0.7 g/l) and ammonium sulfate (0.5-0.7 g/l). The Box-Behnken design was applied in a second-degree quadratic, polynomial regression model to identify the significant effects and the interactions among the above four factors. Based on response curve method the conditions for maximizing phenol removal (initially 0.2 g/l) were recognized as pH 7, temperature 30 degreesC, glucose 0.6 g/l, and ammonium sulfate 0.6 g/l. The inhibition effect of carbon and nitrogen sources beyond a concentration of 0.6 g/l on phenol removal was obvious.

Keywords: Phenol Biodegradation, Pseudomonas putida, Immobilization, Activated Carbon, Experimental Optimization, Continuous Degradation, Calcium

Mehta, S.K., Singh, A. and Gaur, J.P. (2002), Kinetics of adsorption and uptake of Cu²⁺ by Chlorella vulgaris: Influence of pH, temperature, culture age, and cations. Journal of Environmental Science and Health Part A-Toxic/Hazardous Substances & Environmental Engineering, 37 (3), 399-414.

Full Text: J\J Env Sci Hea Par A-Tox Haz Sub Env Eng37, 399.pdf

Abstract: Adsorption and uptake of Cu²⁺ by Chlorella vulgaris were di Cu²⁺uished by extracting the surface-bound Cu²⁺ with EDTA. The uptake of Cu²⁺ followed Michaelis Menten kinetics. The maximum rate of Cu²⁺ uptake (0.362 fmol cell^-1 h^-1) was obtained at pH 6.0. The rate of Cu²⁺ uptake was greater for cultures in the exponential phase of growth, and increased with a rise in temperature from 6 to 25degreesC, thus pointing towards an active mechanism. The maximum number of Cu²⁺ binding sites was 3.245 fmol cell^-1 at pH 4.5. Adsorption of Cu²⁺ was strongly pH-dependent thereby indicating that the number and nature of metal binding sites on the cell surface change with changing chemistry of the solution. Unlike uptake, the adsorption remained unaffected by small changes in temperature. Older cultures displayed a higher Cu²⁺ adsorption capacity than the exponentially growing ones thus suggesting generation of new and/or additional Cu²⁺ binding sites on older cells of C. vulgaris. By pH titration, the cation-exchange capacity of Chlorella, measured in terms of H⁺/Na⁺ exchange, was about 17 fmol cell^-1 at pH 10.5. Negligible cation exchange capacity at and below pH 5.0 indicated that ion exchange was not the sole mechanism of Cu²⁺ adsorption by Chlorella. The uptake and adsorption of Cu²⁺ were inhibited by 100 M of various cations including other heavy metal ions. The general concept that cations competitively inhibit accumulation of metals in living organisms does not hold for C. vulgaris. Non-competitive, uncompetitive and mixed inhibition of Cu²⁺ uptake and adsorption by various cations were more common than competitive inhibition.

Keywords: Adsorption, Cations, Culture Age, Cu²⁺, Uptake, pH, Metal Toxicity, Heavy-Metals, Algae, Transport, Cadmium, Copper, Zinc, Biosorption, Exchange, Protons

Purakayastha, P.D., Pal, A. and Bandyopadhyay, M. (2002), Adsorption of anionic surfactant by a low-cost adsorbent. Journal of Environmental Science and Health Part A-Toxic/Hazardous Substances & Environmental Engineering, 37 (5), 925-938.

Full Text: J\J Env Sci Hea Par A-Tox Haz Sub Env Eng37, 925.pdf

Abstract: This study was undertaken to evaluate the efficiency of rubber granule, a low-cost adsorbent for the removal of sodium dodecyl sulfate (SDS) that is a representative member of anionic surfactant (AS). In the batch experiments conducted at an initial concentration range of 2-6 mg/l, it was found that the rubber granules selected could remove SDS from water up to 90%. Kinetic profiles were developed for various conditions. Effects of adsorbent size, initial adsorbate concentration and adsorbent dose, pH, Ca²⁺ ion concentration, Fe²⁺ ion concentration, Cl^- ion concentration, and ionic strength on the adsorption of SDS on rubber granules were studied. The adsorption isotherm studies were also conducted.

Keywords: Anionic Surfactant, Adsorption, Removal, Rubber Granules, Water

Annadurai, G., Juang, R.S. and Lee, D.J. (2002), Biodegradation and adsorption of phenol using activated carbon immobilized with Pseudomonas putida. Journal of Environmental Science and Health Part A-Toxic/Hazardous Substances & Environmental Engineering, 37 (6), 1133-1146.

Full Text: J\J Env Sci Hea Par A-Tox Haz Sub Env Eng37, 1133.pdf

Abstract: This paper examined the removal efficiency of phenol from aqueous solution using a suspended culture of Pseudomonas putida (ATCC 3180) or the activated carbon on which the microorganism was immobilized. The kinetics of phenol degradation by immobilized and pure cells was studied. Experiments were performed at various phenol concentrations (0.1-0.4 g/L), pH, ([7-9]) temperature (30-36degreesC), and concentrations of glucose (0.5-0.7 g/L) and (NH₄)₂SO₄ (0.5-0.7 g/L). The presence of activated carbon markedly enhanced the degradation efficiency, showing its ability of protecting microbes from confronting shock loads of organic pollutants. Degradation rate increased with increasing substrate concentration and decreased after reaching a maximum, indicating substrate-inhibition kinetics. In addition, the degradation rate for immobilized cells was much higher than that of free cells. The inhibition effect for phenol degradation was described by the Andrews model. The kinetic parameters were also determined.

Keywords: Biodegradation, Adsorption, Phenol, Pseudomonas putida, Activated Carbon, Continuous Degradation, Kinetics, Biosorption, Calcium, Sludge

Tan, K.F., Chu, K.H., Sen Gupta, B. and Hashim, M.A. (2002), Studies on fixed-bed biosorption and elution of copper using polyvinyl alcohol-immobilized seaweed biomass. Journal of Environmental Science and Health Part A- Toxic, Hazardous Substances & Environmental Engineering, 37 (9), 1621-1632.

Full Text: J\J Env Sci Hea Par A-Tox Haz Sub Env Eng37, 1621.pdf

Abstract: Biosorption of copper by inactivated biomass of the brown marine alga Sargassum baccularia immobilized in polyvinyl alcohol (PVA) beads was investigated. PVA-immobilized biomass beads were packed in a laboratory-scale fixed-bed column and subjected to three consecutive cycles of copper loading and elution. Bound copper was eluted with solutions containing a range of ethylenediaminetetraacetic acid (EDTA) concentrations. Up to 100% of the bound copper was consistently recovered from immobilized biomass using an aqueous solution containing 4mM EDTA in repeated loading, elution cycles. The PVA-immobilized biomass beads were shown to be robust and stable with little decrease in the copper uptake capacity under dynamic flow conditions. The excellent reusability of the new biosorbent could lead to the development of a viable metal removal technology.

Keywords: Adsorption, Alga Durvillaea-Potatorum, Algae, Aqueous- Solutions, Biosorption, Cadmium, Column, Copper, Fixed Bed, Fixed Bed Column, Fixed-Bed, Fixed-Bed Column, Immobilized Biomass, Lead, Metal- Ions, Multiple Cycles, Removal, Sargassum, Sargassum Sp, Undaria-Pinnatifida, Waste Biomass

Choi, J.Y. and Kim, D.S. (2002), Adsorption behavior of zinc and cadmium ion on granular activated carbon in singular and binary systems and the influence of nitrilotricetic acid as a complexing agent. Journal of Environmental Science and Health Part A-Toxic/Hazardous Substances & Environmental Engineering, 37 (9), 1701-1719.

Full Text: J\J Env Sci Hea Par A-Tox Haz Sub Env Eng37, 1701.pdf

Abstract: Adsorption characteristics of zinc and cadmium ion on granular activated carbon have been studied in dynamic and equilibrium aspects and singular and binary adsorption behavior were compared. Based on the van’t Hoff equation, reaction orders and rate constants were observed to increase as initial concentration of adsorbate was raised for both metal ions. Adsorption of Zn and Cd ion was found to increase with temperature, and this endothermic nature of adsorption reaction was further verified by thermodynamic calculation. Taking nitrilotriacetic acid (NTA) as a ligand, the influence of complexing agent was examined and the variation of adsorption percentage was found to closely relate with the change in ionic form of NTA depending upon pH conditions and amount of complexing agent used. Features of binary adsorption are discussed for several influential parameters and experimental observations for both ions were correlated with a predicted adsorption isotherm based on a Langmuir multi-component model.

Keywords: Adsorption, Zn and Cd Ion, Binary System, Thermodynamic Calculation, Nitrilotriacetic Acid, Heavy-Metal Ions, Goethite, Water

Yuan, T., Hu, J.Y., Ong, S.L., Luo, Q.F. and Ng, W.J. (2002), Arsenic removal from household drinking water by adsorption. Journal of Environmental Science and Health Part A-Toxic/Hazardous Substances & Environmental Engineering, 37 (9), 1721-1736.

Full Text: J\J Env Sci Hea Par A-Tox Haz Sub Env Eng37, 1721.pdf

Abstract: Geogenic inorganic arsenic contamination in drinking water has been raising public health concern especially in developing countries. Cost-effective and stopgap arsenic removal method for household use (cooking and drinking) is very urgent. Several iron treated natural materials such as Fe-treated activated carbon (FeAC), Fe-treated gel beads (FeGB) and iron oxide-coated sand (IOCS), were investigated in this study for arsenic removal from dispersed household drinking water supply (scattered wells in the endemic arsenic poisoning areas). IOCS showed consistently good performance in terms of As(III) and As(V) removal in batch tests, column tests and field experiment. As(V) adsorption decreased slightly but As(III) adsorption maintained relatively stable when the pH value was increased from 5 to 9. In strong hardness water (612.5 mg/L CaCO₃) As(III) adsorption efficiency was noted to decrease. The adsorption data obtained in column test fitted well to the Langmuir isotherm model. The adsorbent recovery efficiency was above 94% when using 0.2N NaOH regenerated the columns. In addition, 200 L of product water was produced by the household device (containing 3.0 kg IOCS produced) when the influent arsenic concentration ranging from 0.202 to 1.733 mg/L was encountered during the field experimental study conducted in Shanyin County, China. Neither the iron leaching nor other water quality deterioration was observed. It was noted in this study that IOCS is a promising medium for arsenic removal from household drinking water supplies.

Keywords: Arsenic Removal, Household Drinking Water, Adsorption, Iron-Oxide Coated Sand, Iron, Groundwater, Bangladesh, Sorption, Contamination, Cancer, As(V), Risk

Parkpian, P., Leong, S.T., Laortanakul, P. and Poonpolwatanaporn, P. (2002), Environmental applicability of chitosan and zeolite for amending sewage sludge. Journal of Environmental Science and Health Part A-Toxic/Hazardous Substances & Environmental Engineering, 37 (10), 1855-1870.

Full Text: J\J Env Sci Hea Par A-Tox Haz Sub Env Eng37, 1855.pdf

Abstract: This study investigated the potential leachability of toxic heavy metals and pathogenic reduction in sewage sludge using chitosan and zeolite as adsorbing materials. Experiments were conducted on chitosan-sludge and zeolite-sludge mixtures in the application ratio of 0.1 : 10, 0.5: 10, 1.0: 10, 2.0: 10, 3.0: 10, and 4.0: 10, respectively, and examined their capacities to bind some heavy metals (Zn, Cu, Ni and Pb) deriving from sewage sludge. Acrylic columns packed with chitosan and zeolite-sewage sludge mixtures in optimum ratio 1.0: 10 and 3.0: 10, respectively, were leached with tap water and sewage effluent at different pH levels. Seven eluate fractions were collected from the leaching test at leachant, dry sludge (L, S) ratio fixed to 0.48, 0.95, 1.43, 1,90, 2.38, 2.85, and 3.33 L, kg, respectively, and monitored for heavy metal and fecal coliform reductions. Results from leaching test studies for amended sludge showed that the variation of the observed heavy metal contents were influenced by the pH and eluate fractions of leachants. It was found that from neutral to acid conditions, the mobility of heavy metals in amended sludge mixtures was increased with the decrement of pH value in leachants. Zeolite-sludge was found to have higher percentage of reduced metal bioavailability than chitosan-sludge. It can be seen in column studies, pathogenic reduction in amended sludge mixtures were dependent with eluate fractions and type of amended materials. It was also revealed that chitosan can reduce greater fecal coliform counts in sewage sludge than that of zeolite.

Keywords: Chitosan, Heavy Metals, Leachability, Pathogens, Sewage Sludge, Zeolite

Gupta, S., Pal, A., Ghosh, P.K. and Bandyopadhyay, M. (2003), Performance of waste activated carbon as a low-cost adsorbent for the removal of anionic surfactant from aquatic environment. Journal of Environmental Science and Health Part A-Toxic/Hazardous Substances & Environmental Engineering, 38 (2), 381-397.

Full Text: J\J Env Sci Hea Par A-Tox Haz Sub Env Eng38, 381.pdf

Abstract: In the present study, different low cost adsorbents were screened for their sodium dodecyl sulfate (SDS, an anionic surfactant) removal capacity. Waste activated carbon (WAC) from the aqua purifier has shown high efficiency for SDS removal. The performance evaluation in the presence of various ions (Ca²⁺, SO₄^2-, NO₃^-, and Cl^-) and at various pH was studied. Desorption studies were conducted using simple sonication and pH variation technique. Column adsorption studies were performed. SEM and EDS studies were done on the adsorbing material before adsorption, after adsorption and after desorption of SDS.

Keywords: Anionic Surfactant, Sodium Dodecyl Sulfate (SDS), Adsorption, Waste Activated Carbon (WAC), Extraction, Adsorption, Toxicity, Water

? Wang, L., Chua, H., Wong, P.K., Lo, W.H. and Yu, P.H.F. (2003), Ni²⁺ removal and recovery from electroplating effluent by Pseudomonas putida 5-x cell biomass. Journal of Environmental Science and Health Part A-Toxic/Hazardous Substances & Environmental Engineering, 38 (3), 521-531.

Full Text: 2003\J Env Sci Hea Par A-Tox Haz Sub Env Eng38, 521.pdf

Abstract: Ni2+ and Cu2+ are the major heavy metal ions in electroplating wastewater of Hong Kong. In the present study, Pseudomonas putida 5-x cell biomass was used to remove Ni2+ from electroplating effluent. Ni2+ adsorption capacity of P. putida 5-x cell biomass cultured in sulphate-limiting medium was found to be minimum in early logarithmic growth phase, and maximum of 28.1 mg g(-1) in late stationary growth phase. Pretreated cells by 0.1 mol L-1 HCI could greatly enhance the Ni2+ adsorption capacity of cell biomass from 28.1 to 36.7 mg g(-1) and had no significant effect on biomass loss. The adsorption process of P. putida 5-x fresh cells and pretreated cell all could be expressed with Freundlich isotherm. TEM analyses indicated that acidic pretreatment degraded the superficial layer-capsule outside of the fresh cell to improve the adsorption capacity of cell to Ni2+. The Ni2+ bound by P. putida 5-x cell biomass could be efficiently recovered using 0.1 mol L-1 HCI and the cell biomass could be reused at least five cycles for Ni2+ removal and recovery with 93% above removal efficiency and 99% above recovery rate. Owing to the Cu2+ presented in electroplating wastewater inhibiting Ni2+ adsorption process by P. putida 5-x cell biomass, two-stage biosorption processes should be designed to remove and recover Cu2+ and Ni2+ sequentially from electroplating effluent.

Keywords: Adsorption, Adsorption Capacity, Analyses, Biomass, Biosorption, Biosorption, Capacity, Cell Pretreatment, Cu2+, Desorption, Efficiency, Freundlich, Freundlich Isotherm, Growth, Growth Phase, HCI, Heavy Metal, Heavy Metal Ions, Heavy-Metal, Heavy-Metals, Hong Kong, Immobilized Cells, Ions, Isotherm, L1, Metal, Metal Ions, Minimum, Ni2+, P, Pretreatment, Pseudomonas, Pseudomonas Putida, Pseudomonas Putida 5-X, Ramigera, Recovery, Removal, Removal Efficiency, TEM, Waste-Water, Wastewater

Panayotova, M. and Velikov, B. (2003), Influence of zeolite transformation in a homoionic form on the removal of some heavy metal ions from wastewater. Journal of Environmental Science and Health Part A-Toxic/Hazardous Substances & Environmental Engineering, 38 (3), 545-554.

Full Text: J\J Env Sci Hea Par A-Tox Haz Sub Env Eng38, 545.pdf

Abstract: Influence of zeolite-clinoptilolite transformation in a homoionic (Na) form on zeolite ability to immobilize Pb²⁺, Cd²⁺, Cu²⁺, Zn²⁺ and Ni²⁺ from single ion and multi-component solutions has been studied. Zeolite in Na form exhibits significantly increased ability to remove Cd²⁺, Cu²⁺, and Zn²⁺ from their single ion and multi-component solutions when the water hardness due to Ca²⁺ presence is not high. Zeolite pretreatment with NaCl leads to increased rate of heavy metal ions’ immobilization, as well as to increased distribution coefficients that are indicative for more complete exchange process. Heavy metal ions are more strongly bound to zeolite pretreated with NaCl, compared to natural zeolite. Heavy metal ions immobilization is due to ion exchange adsorption, both in the case of natural and converted in Na form zeolite. Zeolite pretreatment with NaCl practically does not change zeolite selectivity sequence for the ions investigated.

Keywords: Heavy Metal Ions, Wastewater, Natural Zeolite Transformation, Natural Zeolites, Environmental-Protection, Adsorption

Wang, L., Chua, H., Wong, P.K., Lo, W.H. and Yu, P.H.F. (2003), Ni²⁺ removal and recovery from electroplating effluent by Pseudomonas putida 5-x cell biomass. Journal of Environmental Science and Health Part A- Toxic, Hazardous Substances & Environmental Engineering, 38 (3), 521-531.

Full Text: J\J Env Sci Hea Par A-Tox Haz Sub Env Eng38, 521.pdf

Abstract: Ni²⁺ and Cu²⁺ are the major heavy metal ions in electroplating wastewater of Hong Kong. In the present study, Pseudomonas putida 5-x cell biomass was used to remove Ni²⁺ from electroplating effluent. Ni²⁺ adsorption capacity of P. putida 5-x cell biomass cultured in sulphate-limiting medium was found to be minimum in early logarithmic growth phase, and maximum of 28.1 mg g^-1 in late stationary growth phase. Pretreated cells by 0.1 mol L^-1 HCI could greatly enhance the Ni²⁺ adsorption capacity of cell biomass from 28.1 to 36.7 mg g^-1 and had no significant effect on biomass loss. The adsorption process of P. putida 5-x fresh cells and pretreated cell all could be expressed with Freundlich isotherm. TEM analyses indicated that acidic pretreatment degraded the superficial layer-capsule outside of the fresh cell to improve the adsorption capacity of cell to Ni²⁺. The Ni²⁺ bound by P. putida 5-x cell biomass could be efficiently recovered using 0.1 mol L^-1 HCI and the cell biomass could be reused at least five cycles for Ni²⁺ removal and recovery with 93% above removal efficiency and 99% above recovery rate. Owing to the Cu²⁺ presented in electroplating wastewater inhibiting Ni²⁺ adsorption process by P. putida 5-x cell biomass, two-stage biosorption processes should be designed to remove and recover Cu²⁺ and Ni²⁺ sequentially from electroplating effluent.

Keywords: Biosorption, Biosorption, Cell Pretreatment, Desorption, Growth Phase, Heavy-Metals, Immobilized Cells, Ions, Ni²⁺, Pseudomonas putida, Ramigera, Waste-Water

Yeh, C.K.J. and Lin, L.C. (2003), Sorption and desorption kinetics of surfactants TX-100 and DPC on different fractions of soils. Journal of Environmental Science and Health Part A-Toxic/Hazardous Substances & Environmental Engineering,