Title: Journal of Environmental Science and Health Part B-Pesticides Food Contaminants and Agricultural Wastes

Title: Journal of Environmental Science and Health Part B-Pesticides Food Contaminants and Agricultural Wastes

ISO Abbreviated Title: J. Environ. Sci. Health Part B-Pestic. Contam. Agric. Wastes

JCR Abbreviated Title: J Environ Sci Heal B

ISSN: 0360-1234

Issues/Year: 6

Journal Country/Territory: United States

Language: Multi-Language

Publisher: Marcel Dekker Inc

Publisher Address: 270 Madison Ave, New York, NY 10016

Subject Categories:

Agriculture: Impact Factor

Environmental Sciences: Impact Factor 0.582, 81/126 (1999); Impact Factor 0.673, 72/127 (2000)

Public, Environmental & Occupational Health: Impact Factor 0.582, 66/85

? Leistra, M. and Dekkers, W.A. (1977), Some models for adsorption-kinetics of pesticides in soil. Journal of Environmental Science and Health Part B-Pesticides Food Contaminants and Agricultural Wastes, 12 (2), 85-103.

Full Text: 1977\J Env Sci Hea Par B12, 85.pdf

? Clay, S.A., Koskinen, W.C., Allmaras, R.R. and Dowdy, R.H. (1988), Differences in herbicide adsorption on soil using several soil-pH modification techniques. Journal of Environmental Science and Health Part B-Pesticides Food Contaminants and Agricultural Wastes, 23 (6), 559-573.

Full Text: 1988\J Env Sci Hea Par B23, 559.pdf

? Monkiedje, A., Wall, J.H., Englande, A.J. and Anderson, A.C. (1990), A new method for determining concentrations of Endod-S (Phytolacca dodecandra) in water during mollusciciding. Journal of Environmental Science and Health Part B-Pesticides Food Contaminants and Agricultural Wastes, 25 (6), 777-786.

Full Text: 1990\J Env Sci Hea Par B25, 777.pdf

Abstract: A hemolytic method was developed for the quantitative determination of oleanane saponin (Endod-S) in Phytolacca dodecandra (Phytolaccaceae), a plant with potent molluscicidal properties. A chemical method based on thin-layer chromatography (TLC) was used as a control for comparison with a hemolysis test. Standard curves for calibration of both tests of Endod-S gave high correlation coefficients. The hemolysis method gave a correlation coefficient of 0.98 for saponin (Endod-S) levels ranging from 1.6 to 4.2 mg/l. The TLC method gave a correlation coefficient of 0.99 for saponin levels above 1.5 micrograms. Due to the action of saponins on erythrocytes, the hemolysis method could not be used at levels below 1.6 and above 4.2 mg/l. Similarly, sample size limited TLC quantitation of these saponins at levels below 1 microgram. Both the TLC and the hemolysis methods on identical Endod-S water samples gave comparable results at saponin levels between 2 and 6 mg/l. A snail bioassay showed that the LC50 and the LC90 concentrations of Endod-S to the snail Biomphalaria glabrata (albino) were 2.57 and 2.92 mg/l respectively. These values fell in the standard curve range for the hemolysis method thus indicating that the hemolysis method is of practical value for testing Endod-S concentrations that would actually be used in field applications for snail control. The hemolysis method is less expensive than TLC and can be easily adapted to field conditions.

? Keerthinarayana, S. and Bandyopadhyay, M. (1997), Diffusion mechanism of lindane into wood charcoal. Journal of Environmental Science and Health Part B-Pesticides Food Contaminants and Agricultural Wastes, 32 (5), 673-700.

Full Text: 1997\J Env Sci Hea Par B32, 673.pdf

Abstract: The wood charcoal treated by 1N HNO3 (WCT) was used to remove toxic chlorinated pesticide lindane (gamma-HCH) residue from water by the sorption process. Using a simple first order reversible kinetics constants and half time equations, the film and pore diffusion coefficients were determined. Film diffusion was found to be rate limiting step in sorbing lindane by WCT. This was further authenticated by kinetics studies at different initial sorbate concentrations, different sorbent sizes, and different agitation speeds besides interruption test. A pore diffusion model was used to fit the data of kinetics in continuously mixed batch reactors (CMBR), and the tortuosity, external resistance, and surface diffusion effects on lindane sorption by WCT were noticed. The tortuosity values of 15 to 28 were obtained for WCT-lindane system.

Keywords: Lindane, Wood Charcoal, Sorption Kinetics, Removal Rate, Interruption Test, Film Diffusion, Pore Diffusion, Surface Diffusion, External Resistance, Tortuosity, Activated Carbon, United-States, Adsorption, Kinetics, Sorption, Removal, Pesticides

? Keerthinarayana, S. and Bandyopadhyay, M. (1997), Sorption and desorption of lindane by wood charcoal in fixed-bed reactor. Journal of Environmental Science and Health Part B-Pesticides Food Contaminants and Agricultural Wastes, 32 (5), 701-727.

Full Text: 1997\J Env Sci Hea Par B32, 701.pdf

Abstract: Sorption and desorption of lindane (gamma-HCH) by wood charcoal (WC) and wood charcoal treated by 1N HNO3 (WCT) in fixed-bed reactor (FBR) were investigated in this study. WCT revealed a better performance than WC, in removing lindane in FBR. The breakthrough of lindane was significantly affected by the size of WCT, flow rate to the FBR, and depth of WCT bed. The removal of lindane in the presence of mixture of other pesticides was considerably reduced. The design parameters for FBR were calculated based an the bed-depth service time (BDST) approach. Many parameters Viz. depth of sorption zone, velocity of sorption, sorbent use rate, critical bed-depth, bed efficiency, and service time, were determined for design of the fixed-bed. Using the material balance principle, the characteristics of the wave-front were evaluated and found that the wave-front velocity is approximately equal to the sorption velocity determined from the BDST approach. Desorption studies were performed in dilute organic solvent media and they gave an excellent performance in regeneration process.

Keywords: Wood Charcoal, Lindane, Sorption, Desorption, Fixed-Bed Reactor, Breakthrough Curve, Bed-Depth Service Time, Wave-Front Velocity, Pollutants, Adsorption, Removal, Design

? Keerthinarayana, S. and Bandyopadhyay, M. (1998), Assessment of equilibrium time and effect of co-solutes in lindane sorption. Journal of Environmental Science and Health Part B-Pesticides Food Contaminants and Agricultural Wastes, 33 (2), 179-209.

Full Text: 1998\J Env Sci Hea Par B33, 179.pdf

Abstract: The wood charcoal treated by 1N HNO3 (WCT) was used to remove toxic chlorinated pesticide lindane (gamma-HCH) residue from water by the sorption process. The continuously mixed batch reactors (CMBR) were used to study the effect of system parameters, such as initial sorbate concentration, sorbent size, and sorbent dose on the sorption equilibrium time of lindane by WCT. Using a rational approach an appropriate value of the equilibrium time was determined. The assessed equilibrium time from such an approach was found to be less than the value obtained by rough estimate which is commonly adopted in practice. The co-solutes or co-sorbates, such as DDT and pentachlorophenol (PCP) imparted a marked decrease in sorption of lindane, whereas trichlorophenol (TCP) did not affect the removal pattern. WCT showed a preferential sorption of (i) DDT > lindane > alpha-HCH > beta-HCH and (II) PCP > lindane > TCP. At a concentration greater than or equal to 20 mg/l of fertilizers, both urea and single super phosphate (SSP) significantly affected the removal of lindane. However, the effect was relatively higher by SSP than by urea.

Keywords: Lindane, Chlorophenol, Co-Solute, Wood Charcoal, Sorption, Equilibrium Time, Removal Kinetics, Rough Estimate, Rational Approach, Fertilizer, Removal, Adsorption, Adsorbents, Pesticides

Oliveira-Filho, E.C., De-Carvalho, R.R. and Paumgartten, F.J.R. (1999), The influence of environmental factors on the molluscicidal activity of Euphorbia milii latex. Journal of Environmental Science and Health Part B-Pesticides Food Contaminants and Agricultural Wastes, 34 (2), 289-303.

Full Text: 1999\J Env Sci Hea Par B34, 289.pdf

Abstract: The present study was undertaken to investigate the influence of biotic (snail size and presence of food during the test) and abiotic factors (temperature, water hardness and concentration of organic materials) on the molluscicidal activity of Euphorbia milii latex. Bioassays were conducted with B. glabrata (10 snails per concentration) and snail lethality was evaluated after 24 hr and 48 hr of exposure to lyophilized latex solutions. Neither the degree of water hardness, nor the presence of food during the test affected latex-induced snail mortality. The snail size had a minor influence on E. milii-induced snail lethality. Newly-hatched (shell diameter < or = 1 mm) as well as young (3-8 mm) snails were slightly less susceptible than older (10-25 mm) mollusks. On the other hand, the molluscicidal effect of E. milii latex was modified by environmental factors such as temperature (i.e., LC50 and LC90 values were halved for every 10°C rise in temperature) and concentration of organic materials in the water (i.e. the higher the concentration of organic matter, the higher the LC50 value). The efficacy of E. milii latex as a molluscicide can be modified by factors such as water temperature and concentration of organic materials, and to a lesser extent by snail size.

Sudhakar, Y. and Dikshit, A.K. (1999), Kinetics of endosulfan sorption on to wood charcoal. Journal of Environmental Science and Health Part B-Pesticides Food Contaminants and Agricultural Wastes, 34 (4), 587-615.

Full Text: 1999\J Env Sci Hea Par B34, 587.pdf

Abstract: A part of the research work conducted to evaluate the efficiency of a locally available low cost wood charcoal in removing endosulfan, an organochlorine insecticide, has been presented here in this paper. In the batch experiments conducted at 1 mg/l initial concentration of endosulfan, it was found that wood charcoal could remove endosulfan from water up to 95%. Kinetic profiles were developed for various conditions and they followed second order kinetic reactions. Adsorption equilibrium time was determined by two different approaches namely rough estimate and 2% slope criteria. The equilibrium time was found to be 5 hrs. Forward, reverse, and overall reaction rate constants were determined by approximating the kinetic data to the first order reversible kinetic model. Rate constants increased with increasing initial concentration of endosulfan Rate limiting process was determined by using kinetics data and further confirmed by the multiple interruption test. Pore and film diffusion coefficients were determined from the half time equations. Film diffusion appeared to be the rate limiting which was further supported by the multiple interruption test.

Keywords: Activated Carbon, Adsorption

Mahramanlioğlu, M., Kizilcikli, İ., Biçer, İ.Ö. and Tunçay, M. (2000), Removal of 2,4-D from aqueous solution by the adsorbents from spent bleaching earth. Journal of Environmental Science and Health Part B-Pesticides Food Contaminants and Agricultural Wastes, 35 (2), 187-200.

Full Text: 2000\J Env Sci Hea Par B35, 187.pdf

Abstract: The removal of 2,4-d (2,4-dichlorophenoxyacetic acid) from aqueous solutions by activated spent bleaching earths (SBE) was studied at 20°C. Experiments were performed as a function of time, initial concentration, dose and particle size of the adsorbent. The Langmuir and Freundlich adsorption equations were fitted by the adsorption data obtained. The values of Langmuir and Freundlich constants were determined. The adsorption kinetic was found to follow Lagergren equation. Both the boundary layer and intraparticle diffusion played important roles in the adsorption rate of 2,4-d. As the size of the adsorbent increased, the time to reach equilibrium increased but adsorption capacity decreased.

Keywords: Pesticides, 2,4-d, Adsorption of Pesticides, Spent Bleaching Earth, Boundary Layer and Intraparticle Diffusion, Adsorption, Soil

? Aguer, J.P., Hermosin, M.C., Calderon, M.J. and Cornejo, J. (2000), Fenuron sorption on homoionic natural and modified smectites. Journal of Environmental Science and Health Part B-Pesticides Food Contaminants and Agricultural Wastes, 35 (3), 279-296.

Full Text: 2000\J Env Sci Hea Par B35, 279.pdf

Abstract: The adsorption isotherms of fenuron (1,1-dimethyl-3-phenylurea) on three smectites (SWy and SAz montmorillonites and SH hectorite) differing in their layer charge (SH

Keywords: Acid, Adsorption, Adsorption Isotherms, Adsorption Mechanisms, Alkylammonium, Aqueous-Solution, Atrazine, Clay Mineral, Components, Desorption, Environment, Exchangeable Cation, Fenuron, Herbicide, Inorganic, Interaction, Isotherms, Minerals, Mobility, Modified, Natural, Organic, Organo-Clays, Organoclays, Parameters, Quaternary, Saturation, Sites, Smectites, Soil, Solubility, Sorption, Surface, Water

Ghosh, P.K., Philip, L. and Bandyopadhyay, M. (2001), Anaerobic treatment of atrazine bearing wastewater. Journal of Environmental Science and Health Part B-Pesticides Food Contaminants and Agricultural Wastes, 36 (3), 301-316.

Full Text: J\J Env Sci Hea Par B36, 301.pdf

Abstract: Performance of mixed microbial anaerobic culture in treating synthetic wastewater with high Chemical Oxygen Demand (COD) and varying atrazine concentration was studied. Performance of hybrid reactors with wood charcoal as adsorbent, with a dose of 10 g/l and 40 g/l, along with the microbial mass was also studied. All the reactors were operated in sequential mode with Hydraulic Retention Time (HRT) of 5 days. In all the cases, COD removal after 5 days was found to be above 81%. Initial COD was above 1000 mg/l. From a hybrid reactor COD removal after 2 days was observed to be 90%. Atrazine reduction after 5 days by microbial mass alone was 43.8%, 40% and 33.2% with an initial concentration of 0.5, 1.0 and 2.0 mg/l respectively. MLSS on all the cases were almost same. Increasing MLSS concentration by about 2 fold did not increase the atrazine removal efficiency significantly. Maximum atrazine removal was observed to be 64% from the hybrid reactor with 10 g/l of wood charcoal and 69.4% from the reactor with 40 g/l of wood charcoal. Atrazine removal from the hybrid reactors after 15 days were observed to be 35.7% and 38.7%, which showed that the higher dose of wood charcoal in hybrid reactor did not improve the atrazine removal efficiency significantly. Specific methanogenic activity test showed no inhibitory effect of atrazine on methane producing bacteria. The performance of anaerobic microorganisms in removing atrazine with no external carbon source and inorganic nitrogen source was studied in batch mode. With an initial concentration of 1.0 mg/l, reduction of atrazine by the anaerobic microorganisms in absence of external carbon source after 35 days was observed to be 61.8% where as in absence of external carbon and inorganic nitrogen source the reduction was only 44.2% after 150 days. Volatilization loss of atrazine was observed to be insignificant.

Keywords: Atrazine, Anaerobic Degradation, Mixed Culture, Pesticide, Biodegradation, Triazine Herbicides, S-Triazines, Degradation, Biodegradation, Mineralization, Pseudomonas, Metabolites, Persistence, Nebraska, Water

Tsai, W.T., Chang, C.Y., Lin, M.C., Chien, S.F., Sun, H.F. and Hsieh, M.F. (2001), Characterization of activated carbons prepared from sugarcane bagasse by ZnCl₂ activation. Journal of Environmental Science and Health Part B-Pesticides Food Contaminants and Agricultural Wastes, 36 (3), 365-378.

Full Text: J\J Env Sci Hea Par B36, 365.pdf

Abstract: Activated carbons were prepared from the agricultural waste of sugarcane bagasse by the chemical activation with zinc chloride (ZnCl2) at the activation temperature of 500 degreesC with soaking time of 0.5 hour. The influence of activation parameters on the final carbon products was examined by varying the impregnation ratio (i.e., mass ratio of added ZnCl2, to bagasse) and bagasse size. The physical properties of carbon products were characterized by nitrogen adsorption/desorption isotherms (at 77 K) and helium displacement method. The surface area and pore volume of carbons were thus obtained by the BET equation and t-plot method. Also, the particle density and porosity of carbons were estimated by the total pore volume and true density. The increases of the values of surface area and pore volume are approximately proportional to the impregnation ratio. The microporous carbon product with the BET surface area of 905 m2/g and total pore volume of 0.44 cm3/g was obtained in the present study. Further, the adsorption isotherms of two acid dyes from aqueous solutions onto the carbon products were performed at 30 degreesC. The results show that the adsorption isotherms of acid dyes with high molecular weight or large molecular size on the microporous adsorbents of activated carbons are plateau forms, indicating multilayer adsorptions, which may be attributed to the steric hindrance of the adsorbate molecules.

Keywords: Agricultural Waste, Sugarcane Bagasse, Chemical Activation, Activated Carbon, Characterization, Acid Dye, Agricultural By-Products, Zinc-Chloride Activation, Cane Bagasse, Corn Cob, Waste, Decolorization, Adsorption

Tsai, W.T., Chang, C.Y., Wang, S.Y., Chang, C.F., Chien, S.F. and Sun, H.F. (2001), Utilization of agricultural waste corn cob for the preparation of carbon adsorbent. Journal of Environmental Science and Health Part B-Pesticides Food Contaminants and Agricultural Wastes, 36 (5), 677-686.

Full Text: J\J Env Sci Hea Par B36, 677.pdf

Abstract: In the present study, a series of activated carbons were prepared from agricultural waste corn cob by chemical and physical activations with potassium hydroxide (KOH)/potassium carbonate (K2CO3) and carbon dioxide (CO2). The effect of process variables such as impregnation ratio, impregnation time, activation temperature and soaking time of CO2 was studied in order to relate these preparation parameters with the physical properties of final carbon products. The resulting activated carbons were characterized by nitrogen adsorption-desorption isotherms at 77 K. The surface areas and pore volumes of carbons were estimated by the BET equation, the Langmuir equation and the t-plot method. Under the experimental conditions investigated, the main parameters in the activation of corn cob were found to be the impregnation ratio and activation temperature. The soaking time of CO2 is another important variable, which had a strong effect on the pore volume development. The BET surface area and total pore volume were as large as about 2000 m2/g and about 1.0 cm3/g, respectively. This study showed that the activation of agricultural waste corn cob with KOH/K2CO3 and CO2 was suitable for the preparation of large-surface-area activated carbons.

Keywords: Agricultural Waste, Corn Cob, Activation, Activated Carbon, Physical Characteristics, Chemical Characteristics, Activated Carbons, By-Products, Lignocellulosic Materials, Chemical Activation, Physical Activation, Phosphoric-Acid, Fluidized-Bed, Adsorption, Pyrolysis, Combustion

Tsai, W.T., Chen, C.H. and Yang, J.M. (2002), Adsorption of paraquat on the physically activated bleaching earth waste from soybean oil processing plant. Journal of Environmental Science and Health Part B-Pesticides Food Contaminants and Agricultural Wastes, 37 (5), 453-463.

Full Text: J\J Env Sci Hea Par B37, 453.pdf

Abstract: A series of regeneration experiments with physical activation were carried out on bleaching earth waste from the soybean refining process in a rotary reactor. The influence of activation parameters on the spent clay by varying the holding time of 1 similar to4 hours and temperature of 700 similar to 900 degreesC was determined. The variations of pore properties as well as the change of chemical characteristics in the resulting solids were also studied. Results showed that the resulting samples were type IV with hysteresis loops corresponding to type 113 from nitrogen adsorption-desorption isotherms, indicating slit-shaped mesoporous characteristics. However, the regenerated clays had smaller surface areas (70 similar to 117 m2/g) than that (245 m2/g) of fresh bleaching earth. Under the physical activation conditions investigated, the holding time of 1 hour and temperature of 700 degreesC were found to be optimal conditions for producing mesoporous clay with physical activation. The adsorption of paraquat on regenerated sample was also evaluated. The isotherm showed that the regenerated sample still had a high affinity for this herbicide. Thus, the regeneration of this agro-industrial waste is one option for utilizing the clay resource, and it may be used for water treatment applications to remove organic contaminants.

Keywords: Agro-Industrial Waste, Bleaching Earth, Regeneration, Physical Activation, Characterization, Paraquat, Adsorption, Low-Cost Adsorbent, Organic-Dyes, Spent Earth, Clay, Regeneration, Extraction, Removal, Surface

? Freimund, S., Sauter, M. and Rys, P. (2003), Efficient adsorption of the mycotoxins zearalenone and T-2 toxin on a modified yeast glucan. Journal of Environmental Science and Health Part B-Pesticides Food Contaminants and Agricultural Wastes, 38 (3), 243-255.

Full Text: 2003\J Env Sci Hea Par B38, 243.pdf

Abstract: 1,3-beta-D-Glucan derived from baker’s yeast was chemically modified in two steps yielding crosslinked carboxymethyl glucan as the sodium salt (2). After cation exchange with hexadecyltrimethylammonium chloride, a hydrophobic adsorbent (3) was obtained,which showed an excellent binding of the estrogenic mycotoxin zearalenone with a maximum adsorption of up to 183 mg/g. Compound 3 additionally showed a relatively high adsorption capacity for the trichothecene T-2 toxin of at least 10 mg/g. Starting from 2, various derivatives were prepared by cation exchange using quaternary ammonium salts bearing substituents besides methyl from four to 18 carbon atoms. The adsorption of T-2 toxin on these derivatives were compared with compound 3 leading to the conclusion that 3 is the best adsorbent of all investigated tetraalkylammonium-modified derivatives of 2.

Keywords: Adsorption, Ammonium, Capacity, Carbon, Carboxymethylation, Cellulose, Chloride, Cross-Linking, Crosslinking, Degradation, Detoxification, Epichlorohydrin, Hexadecyltrimethylammonium, Modified, Mycotoxins, Organic Contaminants, Organobentonites, Ozone, Quaternary, Quaternary Ammonium, Sodium, Sorption, Water, Yeast, Yeast Glucan

? El-Nahhal, Y. (2003), Adsorption mechanism of chloroacetanilide herbicides to modified montmorillonite. Journal of Environmental Science and Health Part B-Pesticides Food Contaminants and Agricultural Wastes, 38 (5), 591-604.

Full Text: 2003\J Env Sci Hea Par B38, 591.pdf

Abstract: This study was undertaken to characterize the adsorption mechanism of alachlor and metolachlor on montmorillonite modified with cationic surfactants. Adsorbed amounts of cationic surfactant on montmorillonite surfaces were determined by CNHSO analyzer. Equilibrium concentrations of alachlor and metolachlor were determined by GC and adsorption results were fit to a linear regression equation. The slope of the isotherms (K-d) was normalized to the fraction of organic carbon on montmorillonite complexes to produce corresponding K-oc. Adsorption of surfactants fit very well to Langmuir equation. Increased basal spacing indicates that surfactant molecules could penetrate through the interlayer spacing and arrange themselves in different ways. Equilibrium data of alachlor and metolachlor suggest that adsorption may occur via physical or chemical bonds. K-oc values of alachlor or metolachlor decreased as the fraction of the organic carbon increased in montmorillonite complexes indicating independent adsorption process. Changes of the molar free energy of the adsorption reactions were in the range of physical adsorption, indicating that adsorption reactions are spontaneous and the molecules either adsorb on the surface or penetrate into the inter-layers of montmorillonite-surfactant complex. Careful investigation of the adsorption data suggests that interaction may occur via the active groups such as carbonyl group (-C=O), anilidic (C-N) group and/or phenyl rings. This information may provide better understanding on adsorption mechanism and be useful in designing ecologically acceptable herbicide formulations.

Keywords: Acetochlor, Adsorption, C-N, Carbon, Carbonyl, Cationic Surfactant, Cations, Chemical, Clay, Complex, Complexes, Energy, Equilibria, Formulations, Herbicide, Herbicides, Information, Interaction, Ionic Organic-Compounds, Isotherms, Mechanism, Model-Calculations, Modified, Montmorillonite, Montmorillonite-Surfactant, Organic, Organic Carbon, Physical Adsorption, Range, Soil, Sorption, Surface, Surfaces, Surfactant, Surfactants, Water

? Aksu, Z. and Kabasakal, E. (2005), Adsorption characteristics of 2,4-dichlorophenoxyacetic acid (2,4-D) from aqueous solution on powdered activated carbon. Journal of Environmental Science and Health Part B-Pesticides Food Contaminants and Agricultural Wastes, 40 (4), 545-570.

Full Text: 2005\J Env Sci Hea Par B40, 545.pdf

Abstract: The removal of 2,4-dichlorophenoxyacetic acid (2,4-D), one of the most commonly used phenoxy acid herbicides, from aqueous solution was studied by using acid-washed powdered activated carbon (PAC) as an adsorbent in a batch system. Adsorption equilibrium, kinetics, and thermodynamics were investigated as a function of initial pH, temperature, and initial 2,4-D concentration. Powdered activated carbon exhibited the highest 2,4-D uptake capacity of 333.3 mg g^-1 at 25°C and an initial pH value of 2.0. Freundlich, Langmuir, and Redlich-Peterson isotherm models were used to express the equilibrium data of 2,4-D depending on temperature. Equilibrium data fitted very well to the Freundlich equilibrium model in the studied concentration range of 2,4-D at all the temperatures studied. Three simplified models including pseudo-first-order, pseudo-second-order, and saturation-type kinetic models were used to test the adsorption kinetics. It was shown that the adsorption of 2,4-D on PAC at 25, 35, and 45°C could be best fitted by the saturation-type kinetic model with film and intraparticle diffusions being the essential rate-controlling steps. The activation energy of adsorption (EA) was determined as -1.69 kJ mole-1. Using the thermodynamic equilibrium coefficients obtained at different temperatures, the thermodynamic constants of adsorption (Delta G degrees, Delta H degrees, and AS degrees) were also evaluated.

Keywords: 2,4-Dichlorophenoxyacetic Acid (2,4-D), Powdered Activated Carbon, Equilibrium, Kinetics, Thermodynamics, Kinetics, Sorption, Removal, Equilibrium, Biosorption, Ions, Zinc

? Daneshvar, N., Salari, D., Niaei, A., and Khataee, A.R. (2006), Photocatalytic degradation of the herbicide erioglaucine in the presence of nanosized titanium dioxide: Comparison and modeling of reaction kinetics. Journal of Environmental Science and Health Part B-Pesticides Food Contaminants and Agricultural Wastes, 41 (8), 1273-1290.

Full Text: 2006\J Env Sci Hea Par B40, 1273.pdf

Abstract: The present work mainly deals with photocatalytic degradation of a herbicide, erioglaucine, in water in the presence of TiO₂ nanoparticles (Degussa P-25) under ultraviolet (UV) light illumination (30 W). The degradation rate of erioglaucine was not so high when the photolysis was carried out in the absence of TiO₂ and it was negligible in the absence of UV light. We have studied the influence of the basic photocatalytic parameters such as pH of the solution, amount of TiO₂, irradiation time and initial concentration of erioglaucine on the photodegradation efficiency of erioglaucine. A kinetic model is applied for the photocatalytic oxidation by the UV/TiO₂ system. Experimental results indicated that the photocatalytic degradation process could be explained in terms of the Langmuir-Hinshelwood kinetic model. The values of the adsorption equilibrium constant, K, and the second order kinetic rate constant, k, were 0.116 ppm-1 and 0.984 ppm min-1, respectively. In this work, we also compared the reactivity between the commercial TiO₂ Degussa P-25 and a rutile TiO₂. The photocatalytic activities of both photocatalysts were tested using the herbicide solution. We have noticed that photodegradation efficiency was different between both of them. The higher photoactivity of Degussa P-25 compared to that of rutile TiO2 for the photodegradation of erioglaucine may be due to higher hydroxyl content, higher surface area, nano-size and crystallinity of the Degussa P-25. Our results also showed that the UV/TiO₂ process with Degussa P-25 as photocatalyst was appropriate as the effective treatment method for removal of erioglaucine from a real wastewater. The electrical energy consumption per order of magnitude for photocatalytic degradation of erioglaucine was lower with Degussa P- 25 than in the presence of rutile TiO₂.

Keywords: Erioglaucine, Herbicides, Photocatalysis, Advanced Oxidation Process, TiO₂, Water, TiO₂, Dyes

? Ru, J., Liu, H.J., Qu, J.H., Wang, A.M., Dai, R.H. and Wang, Z.J. (2007), Selective removal of organochlorine pesticides (OCPs) from aqueous solution by triolein-embedded composite adsorbent. Journal of Environmental Science and Health Part B-Pesticides Food Contaminants and Agricultural Wastes, 42 (1), 53-61.

Full Text: 2007\J Env Sci Hea Par B42, 53.pdf

Abstract: A novel composite adsorbent (CA-T) was used for the selective removal of organochlorine pesticides (OCPs) from aqueous solution. The adsorbent was composed of the supporting activated carbon and the surrounding triolein-embedded cellulose acetate membrane. Scanning electron microscopy (SEM), N2 adsorption isotherms and fluorescence methods were used to characterize the physicochemical properties of CA-T. Triolein was perfectly embedded in the cellulose acetate membrane and deposited on the surface of activated carbon. The adsorbent was stable in water and no triolein leakage was detected during the test periods. Some organochlorine pesticides (OCPs), such as dieldrin, endrin, aldrin, and heptachlor epoxide, were used as model contaminants and removed by CA-T in laboratory batch experiments. The adsorption isotherm followed the Freundlich equation and the kinetic data fitted well to the pseudo-second-order reaction model. Results also indicated that CA-T appeared to be a promising adsorbent with good selectivity and satisfactory removal rate for lipophilic OCPs from aqueous solutions when present in trace amounts. The adsorption rate and removal efficiency for lipophilic OCPs were positively related to their octanol-water partition coefficients (log K-ow). Lower residual concentrations of OCPs were achieved when compared to granular activated carbon (GAC).

Keywords: Accumulation, Acetate, Activated Carbon, Activated Carbons, Adsorption, Adsorption, Adsorption Isotherm, Adsorption Isotherms, Adsorption Rate, Cellulose, Contaminants, Electron Microscopy, Fluorescence, Isotherm, Isotherms, Membrane, Microscopy, Model, Octanol-Water Partition Coefficient (Log Kow), Organic-Matter, Organochlorine Pesticides (OCPs), PCBs, Pesticides, Sem, Semipermeable-Membrane Devices, Triolein

? Mohanty, K., Das, D. and Biswas, M.N. (2008), Utilization of Arachis hypogaea hull, an agricultural waste for the production of activated carbons to remove phenol from aqueous solutions. Journal of Environmental Science and Health Part B-Pesticides Food Contaminants and Agricultural Wastes, 43 (5), 452-463.

Full Text: 2008\J Env Sci Hea Par B43, 42.pdf

Abstract: Arachis hypogaea hulls, an agricultural waste, were used to prepare activated carbon by chemical activation with zinc chloride under four different activation atmospheres. The most important parameter in chemical activation was found to be the chemical ratio (activating agent/precursor). Carbonization temperature and time are the other two important variables, which had significant effect on the pore structure of carbon. The maximum Brunquer-Emmett-Teller (BET) surface area and micropore volume of the activated carbon was found to be 418 m2/g and 0.28 cm3/g, respectively. The activated carbon developed shows substantial capability to adsorb phenol from aqueous solutions. The kinetic data were fitted to the models of intraparticle diffusion, pseudo-second-order, and Lagergren, and followed more closely the pseudo-second-order chemisorption model. The isotherm equilibrium data were well fitted by the Langmuir and Freundlich models. Solution pH has significant effect on adsorption and the maximum uptake of phenol was reported at pH 3.5.

Keywords: Activated Carbon, Activated Carbons, Activation, Adsorption, Adsorption, Agricultural Waste, Aqueous Solutions, Arachis Hypogaea Hull, Bagasse, BET, Carbon, Carbonization, Chemical Activation, Chemical Activation, Chemisorption, Cherry Stones, Chloride, Diffusion, Equilibrium, Freundlich, Intraparticle Diffusion, Isotherm, Kinetic, Langmuir, Micropore Olume, Model, Models, Nut, pH, Phenol, Phenol Removal, Pseudo Second Order, Pseudo-Second-Order, Solution pH, Structure, Surface Area, Temperature, Waste, Zinc, Zinc Chloride