Personal Research Database

Full Text: W\Wat Res37, 3803.pdf

Abstract: In this paper, the biodegradation process of 4-nitrophenol (4NP) in a sequencing batch reactor has been investigated. Kinetic tests have been carried out on biomass grown on mixed substrate (4NP plus biogenic substrate) both in the presence of a biogenic substrate fraction in the feed and with 4NP as the sole carbon source. Removal kinetics for all tests is well described by the typical substrate inhibition pattern as predicted by the Haldane equation. In both sets, estimated kinetic parameters are very similar: no beneficial effect of the biogenic fraction is observed on the 4NP removal while increasing trend of 4NP maximum removal rate with the 4NP/COD_TOT ratio in the feed has been observed. This finding has been modelled by estimating the fraction of the total biomass involved in 4NP biodegradation as a function of 4NP concentration in the feed.

High removal rates, short acclimation times and good settling characteristics of produced sludge (observed during the whole working period) confirm the suitability of periodic systems in enhancing the bacterial potentialities for biodegradation of xenobiotic compounds.

Keywords: 4-Nitrophenol Biodegradation, Xenobiotics, Sequencing Batch Reactor, Kinetic Parameters, Haldane Equation

López, F.A., Martín, M.I., Pérez, C., López-Delgado, A. and Alguacil, F.J. (2003), Removal of copper ions from aqueous solutions by a steel-making by-product. Water Research, 37 (16), 3883-3890.

Full Text: W\Wat Res37, 3883.pdf

Abstract: A study is made of the use of a steel-making by-product (rolling mill scale) as a material for removing Cu²⁺ ions from aqueous solutions. The influence of contact time, initial copper ion concentration and temperature on removal capability is considered. The removal of Cu²⁺ ions from an aqueous solution involves two processes: on the one hand, the adsorption of Cu²⁺ ions on the surface of mill scale due to the iron oxides present in the latter; and on the other hand, the cementation of Cu²⁺ onto metallic iron contained in the mill scale. Rolling mill scale is seen to be an effective material for the removal of copper ions from aqueous solutions.

Keywords: Copper, Steel-Making By-Product, Rolling Mill Scale, Cementation, Adsorption

Zhan, X.M. and Zhao, X. (2003), Mechanism of lead adsorption from aqueous solutions using an adsorbent synthesized from natural condensed tannin. Water Research, 37 (16), 3905-3912.

Full Text: W\Wat Res37, 3905.pdf

Abstract: Adsorption is a method for removing lead from wastewater. The adsorption of lead on a new adsorbent synthesized from natural condensed tannin has been investigated using a series of batch adsorption experiments. The study on the adsorption mechanism indicates that the adsorbent performed in aqueous solutions as an ionic exchanger whose end group was sodium ion (Na⁺). One lead(II) ion (Pb²⁺) was adsorbed onto the adsorbent by taking the place of two Na⁺ ions. The maximum exchangeable Na⁺ present on the adsorbent was measured with the proton titration experiments and it was up to 1.0 mmol Na⁺ g^-1 dry adsorbent. To a significant extent, pH influenced the extraction of lead from aqueous solutions. The lead removal efficiency was up to 71%, 87% and 91% with initial solution pH at 3.0, 3.6 and 4.2, respectively. The Langmuir equation fitted the adsorption isotherm data well. The maximum adsorption capacity of lead calculated was 57.5, 76.9 and 114.9 mg lead g^-1 dry adsorbent at initial solution pH of 3.0, 3.6 and 4.2, respectively. Therefore, the adsorbent does offer favorable characteristics in lead removal from acidic wastewater.

Keywords: Adsorption, Adsorption Mechanism, Condensed Tannin, Ion Exchange, Lead Removal

? Wang, H., Appan, A. and Gulliver, J.S. (2003), Modeling of phosphorus dynamics in aquatic sediments: I - model development. Water Research, 37 (16), 3928-3938.

Full Text: 2003\Wat Res37, 3928.pdf

Abstract: A model is developed to study the phosphorus dynamics in aquatic sediments and to conduct dynamic predictions of phosphorus release across a sediment-water interface. The model focuses on the sediment active layer below the sediment-water interface and is based on primary mechanisms regulating phosphorus behavior in sediments, including effective diffusion, bioturbation mixing and burial processes (transport), organic decomposition, sorption kinetic processes and non-linear partitioning (mobilization). The effects of environmental factors such as dissolved oxygen and temperature are taken into account. The model is solved by numerical integration. The primary difference from models in the literature is that the model directly describes the dynamic behavior of dissolved, particulate exchangeable ortho-phosphorus and organic phosphorus in sediments, and incorporates dynamic sorption and non-linear partitioning processes. These improve model mechanisms and allow regulation of phosphorus flux through the sediment reservoir that acts as both a source and sink of phosphorus. (C) 2003 Elsevier Ltd. All rights reserved.

Keywords: Adsorption, Behavior, Development, Diffusion, Dynamic Model, Environmental, Exchange, Kinetic, Kinetics, Lakes, Literature, Model, Modeling, Netherlands, Numerical Computation, Phosphorus, Primary, Release Flux, Sediment, Sediments, Sorption

Bhattacharjee, S., Chakrabarty, S., Maity, S., Kar, S., Thakur, P. and Bhattacharyya, G. (2003), Removal of lead from contaminated water bodies using sea nodule as an adsorbent. Water Research, 37 (16), 3954-3966.

Full Text: W\Wat Res37, 3954.pdf

Anbstract: Adsorption of water soluble lead on polymetallic sea nodule has been studied in detail. Complete decontamination of lead is possible by appropriate sea nodule dosing. Adsorption is also dependent on pH and best adsorption is achieved at pH 6. Beyond pH 6, the desorption of lead from sea nodule surface is practically zero. Residual metal concentrations in the filtrate after adsorption is negligible. Both Freundlich and Langmuir isotherms may reasonably explain adsorption of lead on sea nodule. Chemically bound moisture plays a very crucial role in lead adsorption. Lead adsorptive capability of sea nodule is practically destroyed when calcined at a temperature of 900°C. Lead loading capacity of sea nodule has been estimated at 440 mg of lead per gram of sea nodule. The performance of sea nodule as a lead adsorbent has been successfully tested over six simulated lead contaminated water systems. Lead loading capacity of sea nodule compares favorably with other adsorbents like activated carbon, ion exchange resin, anionic clay, granulated blast furnace slag and natural and treated zeolites.

Keywords: Adsorption, Lead, Sea Nodule, Chemically Bound Moisture, pH_zpc

Ma, W. and Tobin, J.M. (2003), Development of multimetal binding model and application to binary metal biosorption onto peat biomass. Water Research, 37 (16), 3967-3977.

Full Text: W\Wat Res37, 3967.pdf

Abstract: Biosorption of Cr³⁺, Cu²⁺ and Cd²⁺ from binary metal solutions onto peat in the batch systems was investigated at pH 4. The order of maximum uptake was CrCu>Cd and maximum uptake levels of ca. 0.4 mmol/g were observed for chromium and copper while cadmium was taken up to a maximum of ca. 0.2 mmol/g. Co-ion competition resulted in up to 70 percent decrease of primary metal uptake.

A novel approach to multicomponent sorption modelling involving regression to the total metal taken up was adopted. Two extended Langmuir-type models were found to exhibit good fit to the experimental data. Using the simpler model of these, three-dimensional sorption surfaces were generated which describe the metal uptake as a function of equilibrium concentrations of both metals. These methods allow prediction of metal uptakes over a continuum of concentrations of both metals in binary systems.

Keywords: Peat, Biosorption, Modelling, Wastewater Treatment, Metals, pH Effects

Reddad, Z., Gérente, C., Andrès, Y., Thibault, J.F. and Le Cloirec, P. (2003), Cadmium and lead adsorption by a natural polysaccharide in MF membrane reactor: experimental analysis and modelling. Water Research, 37 (16), 3983-3991.

Full Text: W\Wat Res37, 3983.pdf

Abstract: In the present work, Pb²⁺ and Cd²⁺ adsorption onto a natural polysaccharide has been studied in membrane reactors. The process involves a stirred semi-batch reactor for the adsorption step and a microfiltration (MF) process in order to confine the particles. Due to their lower affinity for the biosorbent, Cd²⁺ ions were found to breakthrough the process faster than Pb²⁺ cations. The experimental results showed the technical feasibility of the pilot. A mass balance model based on the Langmuir equilibrium isotherm was used to describe the adsorption process. This relation is able to predict experimental data under different operating conditions: the adsorbent and metal concentrations, and the permeate flow rate. Based on these results, it is demonstrated that the biosorbent studied represents an interesting low-cost solution for the treatment of metal ions polluted waters.

Keywords: Metal Ions, Polysaccharides, Adsorption, Microfiltration, Modelling

Notes: highly cited

Gupta, V.K., Jain, C.K., Ali, I., Sharma, M. and Saini, V.K. (2003), Removal of cadmium and nickel from wastewater using bagasse fly ash: A sugar industry waste. Water Research, 37 (16), 4038-4044.

Full Text: W\Wat Res37, 4038.pdf

Abstract: The bagasse fly ash, an industrial solid waste of sugar industry, was used for the removal of cadmium and nickel from wastewater. As much as 90% removal of cadmium and nickel is possible in about 60 and 80 min, respectively, under the batch test conditions. Effect of various operating variables, viz., solution pH, adsorbent dose, adsorbate concentration, temperature, particle size, etc., on the removal of cadmium and nickel has been studied. Maximum adsorption of cadmium and nickel occurred at a concentration of 14 and 12 mg l^-1 and at a pH value of 6.0 and 6.5, respectively. A dose of 10 g l^-1 of adsorbent was sufficient for the optimum removal of both the metal ions. The material exhibits good adsorption capacity and the adsorption data follow the Langmuir model better then the Freundlich model. The adsorption of both the metal ions increased with increasing temperature indicating endothermic nature of the adsorption process. Isotherms have been used to determine thermodynamic parameters of the process, viz., free energy change, enthalpy change and entropy change.

Keywords: Adsorption, Sugar Industry, Bagasse Fly Ash, Cadmium, Nickel

Notes: highly cited

? Simeonov, V., Stratis, J.A., Samara, C., Zachariadis, G., Voutsa, D., Anthemidis, A., Sofoniou, M. and Kouimtzis, T. (2003), Assessment of the surface water quality in Northern Greece. Water Research, 37 (17), 4119-4124.

Full Text: 2003\Wat Res37, 4119.pdf

Abstract: The application of different multivariate statistical approaches for the interpretation of a large and complex data matrix obtained during a monitoring program of surface waters in Northern Greece is presented in this study. The dataset consists of analytical results from a 3-yr survey conducted in the major river systems (Aliakmon, Axios, Gallikos, Loudias and Strymon) as well as streams, tributaries and ditches. Twenty-seven parameters have been monitored on 25 key sampling sites on monthly basis (total of 22,350 observations). The dataset was treated using cluster analysis (CA), principal component analysis and multiple regression analysis on principal components. CA showed four different groups of similarity between the sampling sites reflecting the different physicochemical characteristics and pollution levels of the studied water systems. Six latent factors were identified as responsible for the data structure explaining 90% of the total variance of the dataset and are conditionally named organic, nutrient, physicochemical, weathering, soil-leaching and toxic-anthropogenic factors. A multivariate receptor model was also applied for source apportionment estimating the contribution of identified sources to the concentration of the physicochemical parameters. This study presents the necessity and usefulness of multivariate statistical assessment of large and complex databases in order to get better information about the quality of surface water, the design of sampling and analytical protocols and the effective pollution control/management of the surface waters. (C) 2003 Elsevier Ltd. All rights reserved.

Keywords: Water Quality, River Water, Statistical Analysis, Nutrients, Heavy Metals, Chemical-Parameters, Fecal Pollution, Aliakmon River

Jeon, B.H., Dempsey, B.A., Burgos, W.D. and Royer, R.A. (2003), Sorption kinetics of Fe(II), Zn(II), Co(II), Ni(II), Cd(II), and Fe(II)/Me(II) onto hematite. Water Research, 37 (17), 4135-4142.

Full Text: W\Wat Res37, 4135.pdf

Abstract: The reactions of Fe(II) and other divalent metal ions including Zn, Co, Ni, and Cd on hematite were studied in single and competitive binary systems with high sorbate/sorbent ratios in 10 mM PIPES (pH 6.8) solution under strict anoxic conditions. Adsorbed Me(II) was defined as extractable by 0.5 N HCl within 20 h, and fixed Me(II) was defined as the additional amount that was extracted by 3.0 N HCl within 7 days. Binary systems contained Fe(II) plus a second metal ion. The extent of uptake of divalent metal ions by hematite was in order of Fe greater than or equal to Zn > Co greater than or equal to Ni > Cd. For all metals tested, there was an instantaneous adsorption followed by a relatively slow stage that continued for the next 1-5 days. This sequence occurred in both single and binary systems, and could have been due to a variety of sorption site types or due to slow conversion from outer- to inner-sphere surface complexes due to increasing surface charge. Sorption competition was observed between Fe(II) and the other metal ions. The displacement of Fe(II) by Me(II) was in order of Ni similar to Zn > Cd, and the displacement of Me(II) by Fe(II) was in order of Cd > Zn similar to Ni > Co. Fixed Fe(II) was in order of Fe + Co (20%) > Fe + Cd (6%) > Fe - Zn (4%) > Fe similar to Ni (4%) after 30 days. There was no fixation for the other metals in single or binary systems. (C) 2003 Elsevier Ltd. All rights reserved.

Keywords: Divalent Metal Ions, Hematite, Slow Sorption Kinetics, Sorption Competition, Hydrous Ferric-Oxide, Metal-Ions, Water Interface, Ferrous Iron, Adsorption, Reduction, Goethite, Cu, Surface, Copper

Notes: highly cited

Davis, T.A., Volesky, B. and Mucci, A. (2003), A review of the biochemistry of heavy metal biosorption by brown algae. Water Research, 37 (18), 4311-4330.

Full Text: W\Wat Res37, 4311.pdf

Abstract: The passive removal of toxic heavy metals such as Cd²⁺, Cu²⁺, Zn²⁺, Pb²⁺, Cr³⁺, and Hg²⁺ by inexpensive biomaterials, termed biosorption, requires that the substrate displays high metal uptake and selectivity, as well as suitable mechanical properties for applied remediation scenarios. In recent years, many low-cost sorbents have been investigated, but the brown algae have since proven to be the most effective and promising substrates. It is their basic biochemical constitution that is responsible for this enhanced performance among biomaterials. More specifically, it is the properties of cell wall constituents, such as alginate and fucoidan, which are chiefly responsible for heavy metal chelation. In this comprehensive review, the emphasis is on outlining the biochemical properties of the brown algae that set them apart from other algal biosorbents. A detailed description of the macromolecular conformation of the alginate biopolymer is offered in order to explain the heavy metal selectivity displayed by the brown algae. The role of cellular structure, storage polysaccharides, cell wall and extracellular polysaccharides is evaluated in terms of their potential for metal sequestration. Binding mechanisms are discussed, including the key functional groups involved and the ion-exchange process. Quantification of metal–biomass interactions is fundamental to the evaluation of potential implementation strategies, hence sorption isotherms, ion-exchange constants, as well as models used to characterize algal biosorption are reviewed. The sorption behavior (i.e., capacity, affinity) of brown algae with various heavy metals is summarized and their relative performance is evaluated.

Keywords: Alginate, Alginic Acid, Biosorbents, Biosorption, Brown Algae, Capacity, Circular-Dichroism, Cr³⁺, Crystalline-Structure, Cu²⁺, Divalent Metals, Elsevier, Evaluation, Groups, Heavy Metal, Heavy Metals, Ion Exchange, Ion-Exchange Properties, Isotherms, L-Guluronic Acid, Mechanisms, Metal, Metals, Models, Pb²⁺, Polysaccharides, Remediation, Removal, Review, Sargassum, Sargassum Fluitans, Science, Sorption, Storage, Structural Components, Uronic Acid Sequence, X-Ray-Diffraction, Zn²⁺

Zeng, L. (2003), A method for preparing silica-containing iron(III) oxide adsorbents for arsenic removal. Water Research, 37 (18), 4351-4358.

Full Text: W\Wat Res37, 4351.pdf

Abstract: A method for preparing iron(III)-based binary oxide adsorbents in a granulated form for arsenic removal was studied. The key step in the method was the simultaneous generation of hydrous ferric oxide (FeOOH) sol and silica sol in situ in one reactor. This eventually led to the formation of Fe-Si complexes. The addition of silica enhanced the granulated adsorbent strength but reduced the arsenic adsorption capacity. An optimum Si/Fe molar ratio in the balance of adsorbent strength and arsenic adsorption capacity was found to be approximately 0.33. The effects of aging time, drying temperature and process pH on adsorbents were also evaluated in the study. X-ray diffraction analysis confirmed that the iron(III) oxide in the Fe-Si binary oxide adsorbents was amorphous, largely due to the retardation of the iron oxide crystallization by the presence of silicate species. The surface area of the Fe-Si adsorbents and the particle size of Fe-Si complexed suspensions were determined as well. The batch strength testing procedure introduced in this study can provide a simple and quick evaluation of granulate strength in a wet status. Generally, this developed method can prepare granulated Fe-Si binary oxide adsorbents for column adsorption of arsenic from water. (C) 2003 Elsevier Ltd. All rights reserved.

Keywords: Arsenic Removal, Ferric Oxide, Silica, Adsorbent, Granulate, Adsorption Properties, Drinking-Water, Ferrihydrite, Goethite, Surface, Health

Notes: highly cited

Yan, G. and Viraraghavan, T. (2003), Heavy-metal removal from aqueous solution by fungus Mucor rouxii. Water Research, 37 (18), 4486-4496.

Full Text: W\Wat Res37, 4486.pdf

Abstract: Biosorption of lead, cadmium, nickel and zinc by live and dead Mucor rouxii biomass treated with NaOH was studied over a range of pH. In the case of dead biomass, low pH resulted in a decrease in the biosorption capacity. At pH 3.0 or less, the inhibition of biosorption of metal ions took place. At pH 4.0 or higher, the biosorption of metal ions increased sharply. Ho’s pseudo-second-order model described the biosorption kinetics better than the Lagergren model. Live biomass had high biosorption capacity, i.e. 35.69, 11.09, 8.46 and 7.75 mg/g at pH 5.0 for Pb²⁺, Ni²⁺, Cd²⁺ and Zn²⁺, respectively. The dead biomass adsorbed metal ions in the order of Pb²⁺, Zn²⁺, Cd²⁺ and Ni²⁺, with the biosorption capability of 25.22, 16.62, 8.36 and 6.34 mg/g at pH 5.0, respectively. At pH 6.0, the capacity of the dead biomass increased to 53.75, 53.85, 20.31 and 20.49 mg/g, respectively. For bi- or multi-metal ion adsorption, biosorption capacity of individual metal ion was reduced in the presence of other metal ions, but the total biosorption capacity increased, indicating the capability of M. rouxii biomass in adsorbing multi-metal ions. In addition, M. rouxii biomasses cultured with different media exhibited the same level of capacity to bind metal ions. Metal ions adsorbed by the biomass could be eluted effectively with HNO₃, while distilled water demonstrated negligible metal elution capability. Regeneration of the biomass with NaOH regained or enhanced the biosorption capacity even after five cycles of adsorption–elution–regeneration.

Keywords: Fungal Biomass, Mucor Rouxii, Heavy-Metal Ions, Adsorption Kinetics, Adsorption Isotherms

? Hu, C.Y., Lo, S.L. and Kuan, W.H. (2003), Effects of co-existing anions on fluoride removal in electrocoagulation (EC) process using aluminum electrodes. Water Research, 37 (18), 4513-4523.

Full Text: 2003\Wat Res37, 4513.pdf

Abstract: Batch experiments with bipolar aluminum electrodes and potentiodynamic polarization tests with monopolar systems were conducted to investigate the effects of the type and concentration of co-existing anions on defluoridation in electrocoagulation (EC) process. The results demonstrate that the type of the dominant anion directs the EC defluoridation reaction. The defluoridation efficiency was almost 100% and most of the fluoride removal reaction occurred on the surface of the anode in the solution without the co-existing anions, due to the electro-condensation effect. In the solutions with co-existing anions, most of the defluoridation took place in bulk solution. The residual fluoride concentration is a function of the total mass of Al(III) liberation from anodes and the types of the functions in the solutions with and without co-existing anions are different. The existence of sulfate ions inhibits the localized corrosion of aluminum electrodes, leading to lower defluoridation efficiency because of lower current efficiency. The presence of chloride or nitrate ions prevented the inhibition of sulfate ions, and the chloride ions were more efficient. Different corrosion types occurred in different anion-containing solutions and the form of corrosion affected the kinetic over-potential. The bypass flow causes the decrease of current efficiency and the proportion of the bypass flow of current increased due to a rise of the kinetic over potential and the conductivity of the solution. (C) 2003 Elsevier Ltd. All rights reserved.

Keywords: Adsorption, Aluminum, Bipolar Electrodes, Chloride, Co-Existing Anion, Corrosion, Corrosion, Current Efficiency, Defluoridation, Dissolution, Electrocoagulation (EC), Fluoride, Gibbsite, Goethite, Growth, Ions, Kinetic, Nitrate, Potentiodynamic Polarization Test, Removal, Waste-Waters

Loukidou, M.X., Matis, K.A., Zouboulis, A.I. and Liakopoulou-Kyriakidou, M. (2003), Removal of As(V) from wastewaters by chemically modified fungal biomass. Water Research, 37 (18), 4544-4552.

Full Text: W\Wat Res37, 4544.pdf

Abstract: Biosorption has been demonstrated to be a useful alternative to conventional treatment systems for the removal of toxic metals from dilute aqueous solution. The objective of this paper was to examine the main aspects of a possible strategy for the removal of arsenates, employing P. chrysogenum biomass. The pretreatment of biomass with common surfactants (as hexadecyl-trimethylammonium bromide and dodecylamine) and a cationic polyelectrolyte was found to improve the biosorption efficiency. The initial biomass showed a relative low affinity for metallic anions, whereas with the application of modified samples a significant uptake of arsenic was observed. Sorption data were well described by typical Langmuir and Freundlich adsorption isotherms. Promising results were obtained in laboratory experiments and effective As(V) removals were observed.

Keywords: Biosorption, Biomass, Modification, Arsenates, Metal Anions Removal

Jeon, C. and Höll, W.H. (2003), Chemical modification of chitosan and equilibrium study for mercury ion removal. Water Research,