Personal Research Database

Full Text: W\Wat Res32, 2315.pdf

Abstract: Chlorophenols are among priority water pollutants which are taken up by aquatic fauna and flora and enriched in the food chains. Acid-activated bituminous shale has been used as an adsorbent for the removal of 2-chlorophenol (MCP) and 2,4-dichlorophenol (DCP) from water and the related process parameters were investigated. Kinetic analysis showed that the adsorption reaction could be approximated by a first-order rate equation for which pore-diffusion was the essential rate-controlling step. Adsorption was endothermic and basically of a physical character. Equilibrium modelling by linearized adsorption isotherms revealed that a Langmuir equation could well represent the observed data. The entropy change of adsorption was more positive for DCP due to its higher polarity. The saturation capacity of the sorbent for both chlorophenols were determined by dynamic column tests, this experimental capacity being lower than the theoretical monolayer capacity envisaged by the Langmuir equation. Adsorption was completely reversible as the retained DCP could be completely desorbed from the column with distilled water as eluant. The results were evaluated within the scope of utilization of cost-effective unconventional sorbents to remove chlorinated organics as possible substitutes for activated carbon. (C) 1998 Elsevier Science Ltd. All rights reserved.

Keywords: 2-Chlorophenol, 2,4-dichlorophenol, Adsorption, Bituminous Shale, Aqueous-Solutions, Activated Carbon, Fly-Ash, Unconventional Sorbents, Sorptive Removal, Waste-Water, Equilibrium, Cesium-137, Pollutants, Adsorbent

Cathalifaud, G., Ayele, J. and Mazet, M. (1998), Aluminium effect upon adsorption of natural fulvic acids onto PAC. Water Research, 32 (8), 2325-2334.

Full Text: W\Wat Res32, 2325.pdf

Abstract: The removal of fulvic acids in natural water can be realised by several physico-chemical processes: activated carbon adsorption, coagulation-flocculation and oxidation. Activated carbon adsorption remains one of the most important processes used in water treatment. Many workers have demonstrated that the value of pH, the ionic composition, the temperature, the salt concentration and the type of carbon act upon the capacity of activated carbon to remove humic substances [Lee, M. C., Snoeyink, V. L. and Crittenden, J. C. (1981) Activated carbon adsorption of humic substances. JAWWA, 440-446; Randtke, S. J. and Jepsen, C. P. (1982) Effects of salts on actived carbon adsorption of fulvic acids. JAWWA 74, 84-93; Weber, W. J., Jr., Voice, T. C. and Jodellah, A. (1983) Adsorption of humic substances: The effect of heterogeneity and system characteristics. J. Am. Wat. Wks. Ass. 75, 612-619; Lafrance, P. and Mazet, M. (1985) Adsorption des acides humiques sur charbon active en poudre. Influence du triphosphate de sodium. Wat. Res. 19, 1059-1064]. Whereas the association of activated carbon and coagulant-flocculent for the removal of organic matter is usually used in the case of an accidental or chronical pollution, only few workers have studied the mechanisms of elimination. The purpose of the present study was to evaluate the percent of removal of natural fulvic acids onto powdered activated carbon and in the presence of aluminium salts. Initially, one method of dosage of the fulvic acids has been chosen. The KMnO₄ oxidizability seemed to be the more efficient method because the pH and the presence of aluminium don’t affect the results. Secondly, curves of the function of the order of introduction of the components, function of the pH values and function of the presence or not of aluminium salts have been drawn. Our results (Fig. 9) show that the adsorption depends upon the values of the acidity constants (pK_a) of the organic molecule, the order of introduction of the components, the PAC electrokinetic potential and the aluminium species (Al³⁺, Al(OH)²⁺, Al(OH)₂⁺, Al(OH)₃, Al(OH)₄^-, ...). The adsorption of the lone organic molecule was more important at low pH (80% of removal at pH 3) than at high pH (10% of removal at pH 8) and the removal decreased strongly between pH 4 and 6; this is certainly due to the formation of anionic substances (fulvates). The electrostatic interactions for a pH greater than 5.5 between PAC and aluminium salts are probably responsible for a modification in the adsorption of natural fulvic acids. If the pH is lower than 5.5 the adsorption of the organic molecule is increased because of a complexation between the fulvic acids and the aluminium ions.

Many workers have demonstrated that aluminium strongly complexes with organic molecules [Backes, C. A. and Tipping, E. (1987) Aluminium complexation by an aquatic humic fraction under acidic conditions. Wat. Res. 21(2) 211-216; Tipping, E., Backes, C. A. and Hurley, M. A. (1988) The complexation of protons, aluminium and calcium by aquatic humic substances: A model incorporating binding-site heterogeneity and macroionic effects. Wat. Res. 22(5) 597-611; Rakotonarivo, E., Tondre, C., Bottero, J. Y. and Mallevialle, J. (1989) Complexation de l’aluminium(III) polymerise et hydrolyse par les ions salicylate. Etude cinetique et thermodynamique. Wat. Res. 23(9) 1137-1145; Sikora, F. J. and McBride, M. B. (1989) Aluminium complexation by catechol as determined by ultraviolet spectrophotometry. Environ. Sci. Technol. 23(3) 349-356; Thomas, F., Bottero, J. Y., Masion, A. and Genevrier, F. (1990) Mechanism of aluminium III hydrolysis with acetic acid and oxalic acid. Geochemistry of the earth’s surface and of mineral formation. 2nd International Symposium, pp. 2-8. Aix en Provence; Cathalifaud, G., Ayele, J. and Mazet, M. (1997) Etude de la complexation des ions aluminium par des molecules organiques: Constantes et stoechiometrie des complexes. Application au traitement de potabilisation des eaux. Wat. Res. 31(4) 689-698]. The particular role of aluminium salts and pH in the adsorption of natural fulvic acids indicated that the carbon efficiency in removing humic substances can be significantly improved by the addition of aluminium salts in solution. (C) 1998 Elsevier Science Ltd. All rights reserved.

Keywords: Coagulation, Adsorption, Activated Carbon, Aluminium, Natural Fulvic Acids, Activated-Carbon Adsorption, Aquatic Humic Substances, Complexation, Heterogeneity, Coagulation, Calcium, Salts, Ions

Gouzinis, A., Kosmidis, N., Vayenas, D.V. and Lyberatos, G. (1998), Removal of Mn and simultaneous removal of NH₃, Fe and Mn from potable water using a trickling filter. Water Research, 32 (8), 2442-2450.

Full Text: W\Wat Res32, 2442.pdf

Abstract: Manganese removal using a biological trickling filter was investigated. Manganese removal was found to be caused by both biological and chemical manganese oxidation. The extent of each oxidation type was assessed. The performance of the trickling filter was tested under both continuous and sequencing batch reactor operation. The effectiveness and throughput for each operational mode were determined as a function of retention time and the advantages of each operational mode were investigated. It was found that the continuous operational mode leads to higher percentage of manganese removal but lower throughput rates when compared with a sequencing batch reactor operation with the same feed concentration and retention time. A series of experiments was also performed in order to investigate the interactions between ammonia, iron and manganese removal when simultaneously present in a biological filter. For low ammonia concentrations there is no serious inhibition of manganese removal. For higher ammonia concentrations inhibition of manganese removal becomes substantial. The presence of iron affects both ammonia and manganese removal negatively, while ammonia and manganese do not significantly affect iron removal. (C) 1998 Elsevier Science Ltd. All rights reserved.

Keywords: Ammonia, Biological Oxidation, Chemical Oxidation, Continuous Operation, Iron, Manganese, Potable Water Sequencing Batch Reactor Operation, Trickling Filter, Manganese

Hu, J.Y., Aizawa, T., Ookubo, Y., Morita, T. and Magara, Y. (1998), Adsorptive characteristics of ionogenic aromatic pesticides in water on powdered activated carbon. Water Research, 32 (9), 2593-2600.

Full Text: W\Wat Res32, 2593.pdf

Abstract: The adsorptive characteristics of ionogenic pesticides on powdered activated carbon were described. The effects of pH on the adsorbabilities of MCPB (an acidic pesticide) and imazalil (a basic pesticide) onto-powdered activated carbon (PAC) were evaluated by correlating I-octanol-water partition coefficients (log P-ow) with the Freundlich adsorption constants over a pH range of 3 similar to 9. After being corrected with pH, the Values of log P-ow were found to be linearly related to the logarithm of k (i.e. log k). For MCPB, log k as well as log P-ow decreased with the increase of pH in the range of pH > pK (a) and became constant in the range of pH < pK (a) and vise versa for imazalil. Adsorption of ionic species ante PAC became negligible at an ionic strength of similar to 10^-3 M when pH-pK (a) was lower than 4 for MCPB and pH-pK (a) higher than-4 for imazalil. Similar relationship between log k and log-p-ow was obtained for other four acidic pesticides (bentazone, : pentachlorophenol, denoseb and MCPP) and two neutral pesticides (imidacloprid and linuron), which suggested that the log P-ow values mainly determined the adsorbabilities of these pesticides onto PAC. The calculation results showed that the activated carbon amount needed (ACAN) for lowering pesticide concentration from 500 to 50 µg/l was also linearly related to log P-ow, and the ACAN for bentazone (log P-ow, 0.11 at pH = 7) Was 51.9 mg/l, while that for imazalil (log P-ow, 3.80 at pH = 8.0)was 3.1 mg/l. (C) 1998 Elsevier Science Ltd. All rights reserved.

Keywords: Organic-Compounds, Aqueous-Solution, Chlorinated Phenols, Sorption, Octanol, Activated Carbon Adsorption, 1-Octanol-Water Partition Coefficient, Ionogenic Aromatic Pesticides, Drinking Water Treatment, Dissociation Constant, pH

Lücking, F., Köser, H., Jank, M. and Ritter, A. (1998), Iron powder, graphite and activated carbon as catalysts for the oxidation of 4-chlorophenol with hydrogen peroxide in aqueous solution. Water Research, 32 (9), 2607-2614.

Full Text: W\Wat Res32, 2607.pdf

Abstract: Solid materials as iron powder, graphite and activated carbon were tested for their catalytic properties for the oxidation of 4-chlorophenol in aqueous solution with hydrogen peroxide. Batch tests were performed at 30°C, and continuous tests with granular activated carbon under ambient conditions (20°C). Iron powder was shown to act as a catalyst for the activation of hydrogen peroxide and owing to this for the oxidation of 4-chlorophenol. The catalytic activity is based on iron ions leached from the iron powder which act as homogeneous catalysts. Thus, the process can be described as a Fenton reaction enabled by a dissolution of iron powder. The same phenomenon was observed when iron impregnated activated carbon was applied as a catalyst. In contrast to iron powder, graphite and activated carbon were found to act as heterogeneous catalysts for the activation of hydrogen peroxide and the oxidation of 4-chlorophenol. During the oxidation of 4-chlorophenol with activated carbon as a catalyst the decomposition of H₂O₂ is significantly slower than in the absence of 4-chlorophenol. This can be explained by the adsorption of 4-chlorophenol, due to which the surface area of the activated carbon available for the decomposition of H₂O₂, is reduced. At the same concentration of catalytic material in batch tests, the oxidation of 4-chlorophenol proceeds much faster when iron powder instead of graphite or activated carbon is used. On the other hand, graphite and activated carbon are stable catalysts not affected by dissolution processes. Activated carbon can be utilized for a continuous process in a fixed bed reactor. For this purpose the efficiency of 4-chlorophenol oxidation in granular activated carbon filled columns was investigated and a 25% conversion of the 4-chlorophenol (1 g l⁻¹) was achieved at a retention time of 26 min.

Keywords: Iron Powder, Graphite, Activated Carbon, Hydrogen Peroxide, 4-Chlorophenol, Aqueous Phase Oxidation

Sing, C. and Yu, J. (1998), Copper adsorption and removal from water by living mycelium of white-rot fungus Phanerochaete chrysosporium. Water Research, 32 (9), 2746-2752.

Full Text: W\Wat Res32, 2746.pdf

Abstract: Adsorption of copper cation(II) in aqueous solutions by living mycelium pellets of Phanerochete chrysosporium was investigated to study the effects of metal concentration, pH, organic solvents and common cation. The maximum copper adsorption capacity of the fungal mycelium estimated with the Langmuir model was 3.9 mmol Cu per gram of dry mycelium compared with 1.04 mmol Cu per gram of a strong acidic ion-exchange resin. The living mycelium also showed a high affinity to copper in diluted solutions. The adsorption distribution coefficient (K) maintained a constant value around 1.61 per gram of adsorbent in the solutions of up to 100 mgCu/l. Ion-exchange of copper cations with fungal biomass accounted for a small part (< 1%) of copper uptake by the fungal mycelium. The high capacity of copper uptake by living mycelium was mainly attributed to adsorption of very tiny colloids of copper hydroxide formed around pH 6, which was observed with scanning electron microscope and indicated by the pH effect on metal adsorption. Compared with an ion-exchange resin which showed a quite consistent adsorption capacity in a pH range of 2.5-5, the living fungal mycelium had an optimal adsorption capacity in a quite narrow pH range around 6. Copper adsorption and desorption on the fungal mycelium was easily repeated by controlling pH, a unique property of the fungal mycelium for continuous removal and recovery of copper cation from water. Organic solvents had little or positive effect on the copper adsorption capacity of living fungal hyphae.

Keywords: Heavy-Metals, Biosorption, Uranium, Copper Adsorption, Metal Removal, Wastewater Treatment, Biosorption, White-Rot Fungus

Kratochvil, D. and Volesky, B. (1998), Biosorption of Cu from ferruginous wastewater by algal biomass. Water Research, 32 (9), 2760-2768.

Full Text: W\Wat Res32, 2760.pdf

Abstract: The biosorbent prepared from Sargassum algal biomass binds approximately 2.3 meq/g of metal cations from water by ion exchange. The values of ion exchange equilibrium constants showed that the affinities of metals towards the biosorbent decrease in the following order Cu>Ca>Fe. A flow-through sorption column was used to continuously and selectively remove Cu²⁺ from the feed containing Cu and Fe ions. A chromatographic effect in the column performance caused by different sorption affinities of the metal ions studied was successfully predicted by the equilibrium column model. The biosorbent saturated with Cu was regenerated with 0.1 M HCl. When Fe(III) was present in the mixed feed solution as suspended solids (SS) the column removed Cu²⁺ by biosorption and Fe(III) solids by in-detpth filtration while producing effluent free ai heavy metals from the feed containing 25 mg/l of Cu²⁺ and Fe(III) as SS in the concentration range of 15-40 mg/l. Effective copper removal/recovery from ferruginous wastewater using Sargassum biosorbent was demonstrated.

Keywords: Heavy-Metal Biosorption, Acid-Mine Drainage, Sargassum Fluitans, Ion-Exchange, pH, Adsorption, Alginate, Cadmium, Fungal, Column, Cu(II) Removal, Biosorption, Sargassum, Ion Exchange

Pavlinić, S. and Piljac, I. (1998), Electrolytic desorption of silver from ion-exchange resins. Water Research, 32 (10), 2913-2920.

Full Text: W\Wat Res32, 2913.pdf

Abstract: Strong base ion-exchange resins Lewatit M 500 and Lewatit M 504 have steep ascending parts of isotherm curves in the range of low silver concentration in solution and can be used for silver extraction from plating rinsing effluents. Common elution methods are very inefficient for silver removal from strong base ion-exchange resins. Hence, the silver regeneration was performed by the electrolysis coupled elution process. During the process, the mass of silver deposited on the cathode and the I(t)-t curves were recorded. The electrolysis current was allowed to decrease to a value that corresponds to about 10% of the silver capacity. This was achieved from Lewatit M 500 at -1.14 V electrolysis potential using the Pt cylinder gauze working electrode and at -1.30 V using the Ni cylinder working electrode and from Lewatit M 504, at -1.10 V using the Pt cylinder gauze working electrode and at -1.19 V using the Ni cylinder electrode. During the first 3 h of the process 60-80% of the silver can be removed. The desorption process depends on the hydrodynamic conditions provided between the resin beads and solution. It is possible to reuse Lewatit M 500 for the silver adsorption and desorption processes at least three times. (C) 1998 Elsevier Science Ltd. All rights reserved.

Keywords: Galvanic Effluents, Silver Removal, Ion-Exchange Resins, Elution Process, Electrolysis Coupled, Elution Process, Cyanide Solutions, Extraction

Manju, G.N., Raji, C. and Anirudhan, T.S. (1998), Evaluation of coconut husk carbon for the removal of arsenic from water. Water Research, 32 (10), 3062-3070.

Full Text: W\Wat Res32, 3062.pdf

Abstract: The adsorption isotherm of As(III) on copper impregnated activated carbon was obtained in a batch reactor. Various parameters such as reaction time, adsorbent dose, initial concentration of adsorbate, pH, and temperature were studied to establish optimum conditions. Maximum adsorption capacity was observed at pH 12.0. The adsorption isotherm was also affected by temperature since the adsorption capacity was increased by raising the temperature from 30 to 60°C. The experimental adsorption data fitted reasonably well to the Langmuir isotherm. The mass transfer coefficients as a function of initial sorbate concentration have been determined. Arsenic(III) can be successfully removed from synthetic and industrial wastewaters. Desorption studies revealed that spent adsorbent can be regenerated and reused by 30% H₂O₂ in 0.5 M HNO₃. (C) 1998 Elsevier Science Ltd. All rights reserved.

Keywords: Arsenic(III), Activated Carbon, Langmuir Isotherm, Mass Transfer Coefficient, Activated Carbon, Aqueous-Solution, Waste-Water, Adsorption, Hydroxide, Silica

Ajmal, M., Khan, A.H., Ahmad, S. and Ahmad, A. (1998), Role of sawdust in the removal of copper(II) from industrial wastes. Water Research, 32 (10), 3085-3091.

Full Text: W\Wat Res32, 3085.pdf

Abstract: Sawdust, an inexpensive material has been utilised as an adsorbent for the removal of Cu(II) from waste water for their safe disposal. The effects of contact time, pH, concentration, temperature, dose, particle size of the adsorbent and salinity on the removal of Cu(II) have been studied. The equilibrium nature of copper(II) adsorption at different temperature (30-50°C) has been described by the Freundlich and Langmuir isotherm and a tentative mechanism has been proposed. The thermodynamic parameters like free energy, entropy and enthalpy changes for the adsorption of Cu(II) have also been computed and discussed. The kinetics and the factors controlling the adsorption process have also been studied. (C) 1998 Elsevier Science Ltd. All rights reserved.

Keywords: Adsorption, Saw Dust, Copper(II), Surface Complex, Endothermic, Surface Heterogeneity, Chlorocomplex, Recovery, Adsorption, Metals

Notes: highly cited

? Ternes, T.A. (1998), Occurrence of drugs in German sewage treatment plants and rivers. Water Research, 32 (11), 3245-3260.

Full Text: 1998\Wat Res32, 3245.pdf

Abstract: The occurrence of 32 drug residues belonging to different medicinal classes like antiphlogistics, lipid regulators, psychiatric drugs, antiepileptic drugs, betablockers and β2-sympathomimetics as well as five metabolites has been investigated in German municipal sewage treatment plant (STP) discharges, river and stream waters. Due to the incomplete removal of drug residues during passage through a STP, above 80% of the selected drugs were detectable in at least one municipal STP effluent with concentration levels up to 6.3 μg l⁻¹ (carbamazepine) and thus resulting in the contamination of the receiving waters. 20 different drugs and 4 corresponding metabolites were measured in river and stream waters. Mainly acidic drugs like the lipid regulators bezafibrate, gemfibrozil, the antiphlogistics diclofenac, ibuprofen, indometacine, naproxen, phenazone and the metabolites clofibric acid, fenofibric acid and salicylic acid as well as neutral or weak basic drugs like the betablockers metoprolol, propranolol and the antiepileptic drug carbamazepine were found to be ubiquitously present in the riversand streams, mostly in the ng l⁻¹-range. However, maximum concentrations were determined up to 3.1 μg l⁻¹ and median values as high as 0.35 μg l⁻¹ (both bezafibrate). The drugs detected in the environment were predominantly applied in human medicine. It can therefore be assumed that the load of municipal STP effluents in the surface water highly influences the contamination. Due to their wide-spread presence in the aquatic environment many of these drugs have to be classified as relevant environmental chemicals.

Keywords: Drugs, Antiphlogistics, Lipid Regulating Agents, Anticancer Agents, Diazepam, Betablockers, Β2-Sympathomimetics, Carbamazepine, Rivers And Streams, Sewage Treatment Plant Effluents

Dimitrova, S.V. and Mehandgiev, D.R. (1998), Lead removal from aqueous solutions by granulated blast-furnace slag. Water Research, 32 (11), 3289-3292.

Full Text: W\Wat Res32, 3289.pdf

Abstract: The removal of lead by sorption on granulated blast-furnace slag has been investigated as a function of pH, the metal ion concentration, the particle size and the amount of sorbent. It has been established that the process occurs with increasing pH. It was found that the dependence of the process on pH is similar to the dependence of the formation of soluble and insoluble hydrolysis products of lead on pH. but the efficient lead removal by granulated slag is occurred at pH values lower than precipitation pH values, i.e, the sorption is a predominating process. The equilibrium in the slag/lead solution system is described by the Freundlich adsorption isotherm. The constants in the Freundlich equation have been calculated for different slag particle sizes at pH (in) = 5.0-5.1. The percentage of lead removal at equilibrium increases with increasing slag amount but the sorption capacity decreases. Depending on the conditions, a percent lead removal of 97-98% can be achieved. The results obtained could be useful for the application of granulated slag for the Pb-ions removal from industrial waste water.

Keywords: Heavy-Metals, Adsorption, Sorption, Pb-Ions, Removal, Granulated Blast-Furnace Slag, pH Effects

Degraffenreid, N. and Shreve, G.S. (1998), The effect of cadmium on the kinetics of trichloroethylene biodegradation by Pseudomonas (Burkolderia) picketti PK01 under denitrifying conditions. Water Research, 32 (11), 3398-3402.

Full Text: W\Wat Res32, 3398.pdf

Abstract: Pollution resulting from leaking and failing landfills is of concern to public health due to contamination of community drinking water. Chlorinated aliphatic hydrocarbons such as trichloroethylene (TCE) are common to both municipal and hazardous waste landfills and are potential contaminants of groundwater. Landfill leachate typically contains large amounts of organic carbon, nitrogen, and heavy metals and possesses a low redox potential. The kinetics of TCE degradation using a toluene oxidizing bacteria Pseudomonas (Burkholderia) picketti PK01 under nitrate reducing conditions was determined both in the presence and absence of the common landfill contaminant cadmium. A first order rate law was found to describe TCE degradation by Pseudomonas (Burkholderia) picketti PK01 over the TCE concentration range investigated. The rate constant for TCE degradation under denitrifying conditions in the absence of cadmium was 2.1×10^-4 ml/µg protein/h. The rate constant for TCE degradation in the presence of 5 ppm cadmium was determined to be 6.5×10^-5 ml/µg protein/h: representing a sixty nine percent decrease in the rate constant. Significant TCE degradation occurred over the course of the experiments. Results indicate that the presence of 5 ppm of cadmium had the effect of decreasing the TCE degradation activity of the microorganism Burkholderia picketti PK01. Implications for remediation and prediction of biodegradation of TCE in landfill impacted groundwater is discussed. (C) 1998 Elsevier Science Ltd. All rights reserved.

Keywords: TCE Biodegradation, Kinetics, Denitrifying Conditions, Landfill Leachate

Lièvremont, D., Seigle-Murandi, F. and Benoit-Guyod, J.L. (1998), Removal of PCNB from aqueous solution by a fungal adsorption process. Water Research,