Personal Research Database

Full Text: W\Wat Sci Tec39, 1.pdf

Abstract: Runoff was collected from 4 roofs, 3 courtyards and 6 streets on an experimental catchment in central Paris, and analysed for SS, VSS, COD, BOD₅, hydrocarbons, heavy metals both as regards dissolved and particle fractions. Whereas street runoff showed important SS, COD and hydrocarbon loads, roof runoff was noticeable for its high concentration of heavy metals. These concentrations in comparison with water quality standards enhance the importance of runoff pollution. The use of sample settling for runoff treatment is discussed on the basis of data concerning the distribution between dissolved and particle bound pollution loads, along with settling velocity measurements. Runoff particles were found to be highly contaminated with heavy metals and hydrocarbons, which raised the problem of sludge disposal.

Stefanova, R.Y. (1999), Kinetics of removal of zinc ions from aqueous solutions by a modified acrylnitrile copolymer. Water Science and Technology, 39 (8), 139-146.

Full Text: W\Wat Sci Tec39, 139.pdf

Abstract: The kinetics of removal of zinc ions from aqueous solutions by a modified acrylnitrile copolymer containing carboxyl and amino groups has been investigated. The dependence of the rate of removal on the intensity of stirring, the size of the sorbent’s particles, the initial concentration of metal ions and the temperature of the solution have been established. Attempts have been made to identify the rare limiting step and to determine the batch kinetic parameters. The limiting conditions of the transition from external to intraparticle diffusion step of mass transfer in a sorption system have been determined. The coefficients of intraparticle diffusion and the energy of activation of the sorption process have been established. The data obtained in this work show that the modified polymer with a high sorption capacity and very good kinetic characteristics can be successfully used for removal of heavy metal ions from water solutions and industrial wastewaters. (C) 1999 Published by Elsevier Science Ltd on behalf of the IAWQ. All rights reserved.

Keywords: Acrylnitrile Copolymer, Mass Transfer, Sorption Kinetics, Zinc Removal

Ouki, S.K. and Kavannagh, M. (1999), Treatment of metals-contaminated wastewaters by use of natural zeolites. Water Science and Technology, 39 (10-11), 115-122.

Full Text: W\Wat Sci Tec39, 115.pdf

Abstract: This paper assesses the potential of natural zeolite utilization as a low-cost in exchange material for heavy metals removal. Two natural zeolites, clinoptilolite and chabazite, have been evaluated with respect to their selectivity and removal performance for the treatment of effluents contaminated with mixed heavy metals (Pb, Cd, Cu, Zn, Cr, Ni and Co). The effects of relevant parameters such as chemical treatment, metals concentration, pH, and presence of competing ions were examined. The results showed that the received zeolites contained exchangeable K, Ca and Na ions, bur exposing them to concentrated NaCl solutions converted them to a homoionic state in the Na form which improved their exchange capacity. Clinoptilolite and chabazite exhibited different selectivity profiles for all metals studied except for Pb for which both zeolites performed exceptionally well.

The results also showed that chabazite exchange capacity is superior to that of clinoptilolite mainly due to the higher Al substitution of Si which provides chabazite with a negative framework favourable to higher exchange capability. The pH was found to have an effect on metal removal as it can influence both the character of the exchanging ions and die zeolite itself. Overall, the removal mechanism was controlled by ion exchange and precipitation was proven negligible. (C) 1999 IAWQ Published by Elsevier Science Ltd. All rights reserved.

Keywords: Natural Zeolites, Heavy Metals, Removal Efficiency, Ion Exchange, Effluent Treatment, Heavy-Metals, Removal

Bux, F., Atkinson, B. and Kasan, H.C. (1999), Zinc biosorption by waste activated and digested sludges. Water Science and Technology, 39 (10-11), 127-130.

Full Text: W\Wat Sci Tec39, 127.pdf

Abstract: Biological matter is known for its ability to biosorb solubilised heavy metal ions to its surface. Experiments were therefore conducted to assess the biosorptive capacity of two waste products of the wastewater treatment industry ie., waste activated and waste digested sludge. Surface charge of each was determined in order to relate electronegativity with biosorptive potential. Activated sludge was found to be more effective than digested sludge for removal of zinc from a metal plating effluent, viz., 5.9 mg Zn/(g sludge)^-1 as opposed to 4.0 mg/g, respectively, as well as producing a higher net negative charge. It was also noted that as initial zinc concentrations in solution increased there was a concomitant increase in sludge biosorption capacity. Activated and digested sludges were capable of biosorbing zinc from a metal plating effluent although activated sludge showed better potential for industrial application. (C) 1999 Published by Elsevier Science Ltd on behalf of the LAWQ. All rights reserved.

Keywords: Biosorption, Electronegativity, Industrial Effluent, Wastewater Sludge, Zinc Metal, Biomass

Charerntanyarak, L. (1999), Heavy metals removal by chemical coagulation and precipitation. Water Science and Technology, 39 (10-11), 135-138.

Full Text: W\Wat Sci Tec39, 135.pdf

Abstract: Synthetic wastewater of pH 1.9, consisted of Zn, Cd, Mn and Mg at concentrations of 450, 150, 1,085 and 3,154 mg/l respectively. It was found that the optimum pH for chemical coagulation and precipitation by lime treatment was more than 9.5, which could decrease the concentration of heavy metals pertinent to the Wastewater Standard of the Ministry of Industry. Moreover, if 0.5 mg/l of polymer was added, it could decrease the concentration of heavy metals further. In addition when sodium sulphide solution was used in secondary treatment, it was also found that the optimum pH by lime in primary treatment was more than 9.5 and the optimum concentration of sodium sulphide was more than 250 mg/l. (C) 1999 Published by Elsevier Science Ltd on behalf of the IAWQ. All rights reserved.

Keywords: Heavy Metals, Zinc, Cadmium, Manganese, Magnesium, Coagulation, Precipitation, Polymer

Lee, C.L., Wang, T.C., Lin, C.K. and Mok, H.K. (1999), Heavy meatals removal by a promising locally available aquatic plant, Najas graminea Del., in Taiwan. Water Science and Technology, 39 (10-11), 177-181.

Full Text: W\Wat Sci Tec39, 177.pdf

Abstract: This study uses an aquatic plant, Najas graminea Del., to treat man-made wastewater containing single and/or binary components of copper, lead, cadmium and nickel. Adsorption experiments demonstrate that the adsorption process correspond to the Lagergren kinetic model with the rare constant close to 0.01 min^-1; meanwhile, the equilibrium results corresponds to the Langmuir adsorption isotherm. Notably, the rate constants of metals are not significantly different between each other. Competitive effect on the adsorption kinetics of cadmium is insignificant with the background solute (lead) concentration up to 10 mg/l; while significant deviation observed with concentration of lead reached 100 mg/l. In addition the maximum adsorption density of cadmium is reduced by around 50% in the presence of 100 mg/l of lead. A simulated copper plating wastewater is also treated by Najas graminea Del, to demonstrate its efficiency in removing metals from wastewater with multi-cations/anions. (C) 1999 Published by Elsevier Science Ltd on behalf of the IAWQ. All rights reserved.

Keywords: Bio-Remediation, Aquatic Plant, Heavy Metals, Sustainable Technology, Hyacinth Eichhornia-Crassipes, Accumulation, Water, Cadmium, Metals, Azolla

Brasquet, C., Subrenat, E. and Le Cloirec, P. (1999), Removal of phenolic compounds from aqueous solution by activated carbon cloths. Water Science and Technology, 39 (10-11), 201-205.

Full Text: W\Wat Sci Tec39, 201.pdf

Abstract: Granular activated carbon (GAC) is easily used in water or wastewater treatment in order to remove organic micropollutants. Recently, a new presentation of activated carbon has been developed: fibrous activated carbon in the form of cloth or felt. This work investigates the adsorption onto activated carbon cloths (ACC) of various phenolic compounds from aqueous solution. Experiments were carried out in batch reactors with two ACCs (called CS 1501 and RS 1301) and their performances were compared with those of GAG. Initial adsorption kinetic coefficients were higher with fibers than with granules due to the direct connection of micropores to the external surface of fibers. Adsorption isotherms were also performed and modelized by Langmuir and Freundlich equations. Adsorption capacities were similar or higher with ACCs than with GAG. The behaviour of the ACC CS 1501 was also studied in a dynamic reactor. The breakthrough curves allowed the determination of high maximum adsorption capacities, 117 mg.g^-1 for phenol. Pressure drops in ACC beds were measured and the influence of various parameters was shown: the activation step, the number of fabric layers, the space between two layers. (C) 1999 IAWQ Published by Elsevier Science Ltd. All rights reserved.

Keywords: Activated Carbon Cloth, Adsorption, Batch Reactor, Dynamic Reactor, Phenolic Compounds, Pressure Drops, Water-Treatment, Adsorption, Fibers

Ricou, P., Lécuyer, I. and Le Cloirec, P. (1999), Removal of Cu²⁺, Zn²⁺ and Pb²⁺ by adsorption onto fly ash and fly ash/lime mixing. Water Science and Technology, 39 (10-11), 239-247.

Full Text: W\Wat Sci Tec39, 239.pdf

Abstract: Disposal of a growing amount of fly ash creates environmental problems due to the leachability of their heavy metal content. Elsewhere, desulfurization treatment in power plants induces pollution by their heavy metals. In this paper, removal of Cu, Zn and Pb by fly ash and fly ash/lime mixing was studied. In the first part of the study, isotherms at different pH were carried out at room temperature. Results show increasing removal with increasing pH. In the second part, experimental design methodology was used. The objectives were to determine the influential parameters among the seven studied for adsorption of copper, zinc and lead, then to study their interactions. Results indicate greater removal by using 100 g.l^-1 of adsorbent with 20% mass of lime at pH 5. However, the preparation of the adsorbent must be modified to increase the role of lime in the removal mechanism.

Keywords: Cd, pH, Experimental Design, Fly Ash/Lime Mixing, Influential Parameters, Interactions, Metallic Ions, Removal

Veeken, A.H.M. and Hamelers, H.V.M. (1999), Removal of heavy metals from sewage sludge by extraction with organic acids. Water Science and Technology, 40 (1), 129-136.

Full Text: W\Wat Sci Tec40, 129.pdf

Abstract: Waste water treatment in activated sludge plants results in the production of large amounts of surplus sludge. After composting the sludge can be reused as fertiliser and soil conditioner in agriculture. Compared to landfilling and incineration, utilisation of sludge-compost is a more sustainable treatment because it recycles both nutrients and organic matter. However the high levels of heavy metals in sludge frequently prevent the reuse of sludge compost in agriculture. The extraction of heavy metals from the sludge before composting is therefore a necessary step to achieve a more sustainable sludge treatment. Extraction of heavy metals by inorganic acids and complexing agents has severe drawbacks. Organic acids could be an attractive extracting agent because the extraction can be performed at mildly acidic conditions (pH 3-5) and they are biologically degradable. The extraction was studied for heavy metals Cu and Zn and for competing metals Ca and Fe. The rate of extraction increases for increasing temperature and citric acid concentration. Cu can be extracted for 60-70% and Zn for 90-100% by citric acid at pH 3-4. A first economic valuation of the extraction and subsequent composting process showed that the total costs of the treatment process are below the costs of incineration. (C) 1999 Published by Elsevier Science Ltd on behalf of the IAWQ. All rights reserved.

Keywords: Compost Utilisation, Cu, Heavy Metal Removal, Sewage Sludge Treatment, Zn

Nicolet, L. and Rott, U. (1999), Recirculation of powdered activated carbon for the adsorption of dyes in municipal wastewater treatment plants. Water Science and Technology, 40 (1), 191-198.

Full Text: W\Wat Sci Tec40, 191.pdf

Abstract: The use and recirculation of powdered activated carbon (PAC) as an advanced treatment for colour removal in municipal wastewater treatment plants is presented. Studied wastewaters consist of domestic effluents with a high portion of dyehouse residual waters. The particularity of the treatment is that PAC is not disposed of before being recirculated several times. Therefore, it enables the use of a great part of the total adsorption capacity of the PAC. A positive side effect is that halogenated and refractory organic compounds, which are not degraded by micro-organisms in a conventional municipal wastewater treatment plant, are removed too. This paper describes results which were obtained in batch experiments and in a pilot plant during two years of observation, and concludes with advantages and drawbacks of this technology.

Keywords: Adsorption, Flocculation (Coagulation), Dye Removal, Powdered Activated Carbon, Wastewater

Viraraghavan, T., Subramanian, K.S. and Aruldoss, J.A. (1999), Arsenic in drinking water: Problems and solutions. Water Science and Technology, 40 (2), 69-76.

Full Text: W\Wat Sci Tec40, 69.pdf

Abstract: The current United States maximum contaminant level for arsenic in drinking water is set at 50 µg/l. Because of the cancer risks involved, Canada has already lowered the maximum contaminant level to 25 µg/l; the United States Environmental Protection Agency is reviewing the current allowable level for arsenic with a view of lowering it significantly. Various treatment methods have been adopted to remove arsenic from drinking water. These methods include 1) adsorption-coprecipitation using iron and aluminum salts, 2) adsorption on activated alumina, activated carbon, and activated bauxite, 3) reverse osmosis, 4) ion exchange and 5) oxidation followed by filtration. Because of the promise of oxidation-filtration systems, column studies were conducted at the University of Regina to examine oxidation with KMnO₄ followed by filtration using manganese greensand and iron-oxide coated sand to examine the removal of arsenic from drinking water; these results were compared with the data from ion exchange studies. These studies demonstrated that As(III)could be reduced from 200 µg/l to below 25 µg/l by the manganese greensand system. In the case of manganese greensand filtration, addition of iron in the ratio of 20: 1 was found necessary to achieve this removal.

Keywords: Ground-Water, Affected People, 6 Districts, West-Bengal, Removal, India, Urine, Contamination, Adsorption, Calamity, Arsenic Removal, Drinking Water, Manganese Greensand, Iron-Oxide Coated Sand

? Weber, Jr., W.J. and LeBoeuf, E.J. (1999), Processes for advanced treatment of water. Water Science and Technology, 40 (4-5), 11-19.

Full Text: 1999\Wat Sci Tec40, 11.pdf

Abstract: A case-oriented approach is used to illustrate developments and applications of biological and physicochemical technologies, either alone or in sequenced arrays, for advanced treatment to facilitate reuse of water in a range of environmental scenarios. Examples cited include chemical oxidation processes for removal of color and oxygen demand from textile mill effluents, sequential anaerobic, aerobic biological treatment of recalcitrant and inhibitory organic compounds in ammunition plant wastewaters, separation and recovery of organic solvents from mixed industrial waste streams, remediation of contaminated subsurface waters, membrane treatment of effluents from secondary biological wastewater treatment plants, and integrated bio-membrane treatment of industrial and municipal wastewaters. The paper provides an overview of methods and applications for source waters of various qualities. It concludes with a generalized guide to technology selection based upon specific water characteristics. (C) 1999 IAWQ Published by Elsevier Science Ltd. All rights reserved.

Keywords: 2,4-Dinitrotoluene, Adsorption, Adsorption, Anaerobic, Aerobic Sequenced Bio-Processes, Bio-Membrane Processes, Biodegradation, Chemical Oxidation, Contaminants, GAC, Membrane Bioreactors, Membrane Processes, Organic-Matter, Sorption, TCE, Water Treatment for Reuse

Drewes, J.E. and Fox, P. (1999), Behavior and characterization of residual organic compounds in wastewater used for indirect potable reuse. Water Science and Technology, 40 (4-5), 391-398.

Full Text: W\Wat Sci Tec40, 391.pdf

Abstract: The scope of this study was to compare the behavior and character of dissolved organic carbon (DOC) during soil-aquifer treatment at different field sites in Arizona and California. To determine biodegradable and residual organic carbon, biodegradability studies using batch tests and a laboratory soil-column system were examined, combined with additional examinations for further characterization (ultrafiltration, adsorption analysis). Based on this comparison, soil-columns in series seemed to be more appropriate to simulate SAT as compared to batch-tests since this test system indicated continuous structural changes of generally poorly degradable organic compounds during SAT. This ongoing change of organic matter was confirmed by field measurements indicating biodegradation as the dominant removal process for DOC during SAT. The level of residual DOC after short-term SAT was similar although wastewater treatment processes differed at the investigated sites. However, increasing source water DOC led to an increase of residual DOG. In general, source water quality, drinking water and wastewater treatment should be viewed as one system in indirect potable reuse projects. (C) 1999 IAWQ Published by Elsevier Science Ltd. All rights reserved.

Keywords: Water-Quality Changes, Groundwater Recharge, Biodegradability, Effluents, Groundwater Recharge, Indirect Potable Reuse, Natural Organic Matter (Nom), Refractory DOC, Soluble Microbial Products (SMP), Soil-Aquifer Treatment (SAT)

Karcher, S., Kornmüller, A. nad Jekel, M. (1999), Removal of reactive dyes by sorption/complexation with cucurbituril. Water Science and Technology, 40 (4-5) 425-433.

Full Text: W\Wat Sci Tec40, 425.pdf

Abstract: Color removal is an important task in textile wastewater treatment. Cucurbituril, a cyclic hexamer with internal hydrophobic cavity, has been studied as sorbent for removal of reactive dyes. Loadings as high as 1 g/g and more were obtained, making the method seem interesting for technical application. A minimum of 1 to 5 mmol/L calcium is needed for efficient sorption. However, salt concentrations of 100 mmol/L and above decrease sorption efficiency due to increased solubility of cucurbituril in salt solutions. The pH has little influence between 4 and 7.5, higher pH-values can result in decreased sorption, The salt influences are similar for most of the tested dyes whereas the pH-effect differs from dye to dye. (C) 1999 IAWQ Published by Elsevier Science Ltd. All rights reserved.

Keywords: Reactive Dyes, Cucurbituril, Sorption, Complexation, Textile Wastewater, Textile Dyes, Cations, Ion

Ansari, M.H., Deshkar, A.M., Kelkar, P.S., Dharmadhikari, D.M., Hasan, M.Z. and Paramasivam, R. (1999), Mercury removal from wastewater by steamed hoof powder. Water Science and Technology, 40 (7), 109-116.

Full Text: W\Wat Sci Tec40, 109.pdf

Abstract: Steamed Hoof Powder (SHP), size < 53 µm, was observed to have high adsorption capacity for Hg(II) with >95% removal from a solution containing 100 mg/L of Hg(II) with only 0.1% (W/V) concentration of SHP. The SHP has good sealing properties and gives clear and odour free effluent. Studies indicate that pH values between 2 and 10 have no effect on the adsorption of Hg(II) on SHP. Light metal ions like Na⁺, K⁺, Ca²⁺ and Mg²⁺ up to concentrations of 500 mg/L and heavy metals like Cu²⁺, Zn²⁺., Cd²⁺, Co²⁺, Pb²⁺, Ni²⁺, Mn²⁺, Cr³⁺, Cr⁶⁺, Fe²⁺ and Fe³⁺ up to concentrations of 100 mg/L do not interfere with the adsorption process. Anions like sulphate, acetate and phosphate up to concentrations of 200 mg/L do not interfere. Chloride interferes in the adsorption process when Hg(II) concentration is above 9.7 mg/L. The adsorption equilibrium was established within two hours. Studies indicate that adsorption occurs on the surface sites of the adsorbent.

Keywords: Adsorption Equilibrium, Biomagnification, Mercury-Chloride Complex, Methylmercury, Steamed Hoof Powder, Sulfur-Mercury Bond

Nassar, M.M. (1999), Intraparticle diffusion of basic red and basic yellow dyes on palm fruit bunch. Water Science and Technology, 40 (7), 133-139.

Full Text: W\Wat Sci Tec40, 133.pdf

Abstract: Rate of intraparticle diffusion was studied for adsorption of two basic dyes, basic red and basic yellow, on particles of palm fruit bunch. The rate process was expressed in terms of square root of time (t^0.5). Discussion of the obtained relationship of equilibrium isotherm and t^0.5 was given. The intraparticle rate diffusion ‘k’ was determined experimentally and the correlation at different dye concentrations and different temperatures was found to follow the form: k = A (variable) (B). The adsorption process was found to be a diffusion controlled process.

Keywords: Aqueous-Solutions, Natural Adsorbents, Textile Effluents, Color Removal, Bagasse Pith, Adsorption, Adsorption Isotherm, Basic Dye, Intraparticle Diffusion, Palm-Fruit Bunch

Fettig, J. (1999), Removal of humic substances by adsorption/ion exchange. Water Science and Technology, 40 (9), 173-182.

Full Text: W\Wat Sci Tec40, 173.pdf

Abstract: This paper gives an overview over the ability of four different sorbent media, activated carbon, anion exchange resins, carbonaceous resins and metal oxides, for the removal of humic sustances. Both sorbent characteristics and solution parameters that affect the ultimate capacities are discussed, and approaches developed in order to describe sorption equilibria and rate of uptake are reported. In addition, successes and failures of predictive models are described. Some general conclusions about favorable conditions for the removal of humic substances by sorption processes are given. (C) 1999 Published by Elsevier Science Ltd on behalf of the IAWQ. All rights reserved.

Keywords: Activated Carbon, Activated Alumina, Adsorption, Humic Substances, Ion Exchange, Predictive Models, Activated Carbon Adsorption, Natural Organic-Matter, Water-Treatment, Gac, Kinetics, Oxygen, Acids, Tests

Heijman, S.G.J., van Paassen, A.M., van der Meer, W.G.J. and Hopman, R. (1999), Adsorptive removal of natural organic matter during drinking water treatment. Water Science and Technology, 40 (9), 183-190.

Full Text: W\Wat Sci Tec40, 183.pdf

Abstract: For the removal of DOC (and colour) several treatment steps are suggested. If it is also necessary to remove hardness nanofiltration is probably the first choice. For colour removal without softening a number of adsorbents are suggested in the literature. In order to estimate the costs of these treatment steps a dynamic column model based on batch experiments was used to predict the service time of the columns filled with different adsorbents. Also the (on site) regeneration of the different adsorbents was investigated in batch experiments. Especially the ion exchange resin was very promising. The costs of the treatment of one m³ water with a column filled with an ion exchange resin was estimated for the investigated case at 0.05 Euro. (C) 1999 published by Elsevier Science Ltd on behalf of the IAWQ. All rights reserved.

Keywords: Chemical Regeneration, Activated Carbon, Colour, DOC, Removal, Column Model, Costs, Adsorption

Gerlach, M. and Gimbel, R. (1999), Influence of humic substance alteration during soil passage on their treatment Behaviour. Water Science and Technology,