Personal Research Database

Full Text: 1994\Wat Sci Tec29, 69.pdf

Abstract: Phenolic waste water from the largest coke coking plant in Poland is treated at a full technical scale. From the very beginning it became evident that very high qualitative variations in short and long periods are to be expected. For this purpose, the biological treatment giant based on activated sludge is protected through preliminary physical-chemical treatment and the results are secured by a final chemical stage of treatment. Nevertheless, improvements in the performance of the treatment plant have been found necessary to introduce. The experienced gained over the last five years has been described and developed improvements have been presented. At the preliminary stage the importance and necessity of preparation was evaluated. It was found essential to use dissolved air flotation, instead of a simple pressured air flotation system. Even with an average relatively high retention in the aeration tanks, there was an uneven distribution of load, dissolved oxygen concentration and oxygen uptake. Dissolved iron or highly dispersed hydroxide particulates in the over flow of the first chemical treatment stage has had a beneficial effect on activated sludge flocs. As a result not only the physical properties but also the overall effect of treatment.

Keywords: Activated Sludge, Biodegradation, Coke Waste, Complex Treatment, Dissolved Oxygen, Flotation, Phenols, Treatment

? Delanghe, B., Nakamura, F., Myoga, H., Magara, Y. and Guibal, E. (1994), Drinking water denitrification in a membrane bioreactor. Water Science and Technology, 30 (6), 157-160.

Full Text: 1994\Wat Sci Tec30, 157.pdf

Abstract: Drinking water denitrification was studied on a membrane bioreactor pilot plant. The nitrate removal yields remained constant at 99 %. The specific denitrification activities averaged 0.16 kg N-NO₃.kg^-1MLSS.d^-1 at 20°C and pH 8, The permeation flux was about 0.5 m³.m^-2.d^-1 throughout the study and did not vary with an increase in the suspended solids concentration. The dependence of the process efficiency on temperature and pH was put into equation, The specific denitrification activity decreased by a factor 1.9 with a temperature decrease of 10°C, The optimal pH was found to be 8 - 8.5. The ethanol consumption was 1.4 g C.g^-1N-NO₃. The membrane bioreactor technique seems to be a promising answer for the nitrate problem of drinking waters.

Keywords: Denitrification, Drinking Water, Ethanol Consumption, Membrane Separation, Nitrate Removal, Plants, Temperature, Ultrafiltration, Water

Lai, J.L., Lo, S.L. and Lin, C.F. (1994), Effects of hydraulic and medium characteristics on solute transfer to surface runoff. Water Science and Technology, 30 (7), 145-155.

Full Text: W\Wat Sci Tec30, 145.pdf

Abstract: A two-stage scouring-based model including two parameters for each stage, the ultimate scoured depth and rate of change of scoured depth, was developed to describe solute transfer to surface runoff. While the first stage is a quick decrease of mass loss of solute to surface runoff, the second stage is a slow one. An experimental flume with a medium packed bed was designed. Four different sizes of glass beads were chosen to be the media and saturated with uniform concentration (20000 ppm) of potassium chloride solution before runoff occurred. In a series of experiments, runoff was passed at varied flow rate, velocities, and depths over the medium bed. Runoff samples were taken at the end of flume and the concentration of potassium chloride analysed. By use of this model, the dimensionless ultimate scoured depth and the dimensionless rate of change of each stage were investigated. The results showed that the Reynolds number within media and the relative length were two important factors affecting mass loss of chemicals.

Keywords: Nonpoint-Source Pollution, Solute Transfer, Scouring-Based Model, Overland Flow, Surface Runoff, Pesticide Runoff, Soil Solution, Water, Chemicals, Interflow, Model

Lai, C.H., Lo, S.L. and Lin, C.F. (1994), Evaluating an iron-coated sand for removing copper from water. Water Science and Technology, 30 (9), 175-182.

Full Text: W\Wat Sci Tec30, 175.pdf

Abstract: In drinking water treatment systems, the conventional process (coagulation, sedimentation and filtration units) cannot remove trace metals efficiently. Iron oxide is an excellent, regenerable adsorbent, and often controls free metals through adsorption. The utilization of heating process for coating iron oxide on sand surface allowed the media to be used in a packed column. The adsorbent media were investigated for removing copper ions from water using both batch and column experimental methods. A one-dimensional convective-dispersive transport model with a combination of second-order kinetic adsorption equation was adopted for predicting copper retention in a 80 cm depth filter bed. The concentration of copper ions in influent ranged from 0.64 to 3.2 mg/l. The experimental results indicated that the copper could be removed completely until the breakpoint. Once breakthrough occurred, the regeneration of the media could be achieved by soaking with acid solution (pH = 3.0). The simulation results of the transport-adsorption equation fit experimental data quite well. Consequently, the coated sand can be applied for the conventional rapid filtration process to remove copper ions from water.

Keywords: Iron Oxide, Adsorption, Filtration, Regeneration, Metal, Copper, Coating, Metal-Bearing Wastes, Drinking-Water, Oxide, Magnetite, Sorption, Ions

Guibal, E., Saucedo, I., Jansson-Charrier, M., Delanghe, B. and Le Cloirec, P. (1994), Uranium and vanadium sorption by chitosan and derivatives. Water Science and Technology, 30 (9), 183-190.

Full Text: W\Wat Sci Tec30, 183.pdf

Abstract: The modification of chitosan, by grafting of oxo-2-glutaric acid, allows its sorption performance to be increased. This enhancement of uptake ability is observed in overall sorption capacity and specificity in sorbing particular metals. This work focuses on the sorption of uranium(VI) and vanadium(V). The sorption isotherms are studied. The experimental results are described according to the Langmuir and Freundlich models. It was shown that uranium sorption is best described by the Freundlich model, while vanadium sorption is difficult to model. The influence of the particle size, significant in the case uranium, but not for vanadium, shows that the sorption mechanism is not the same for the two metals: surface control is predominant in the case of uranium, due to the poor porosity of the sorbents. The control of overall sorption capacity is related to the chemistry of the metal and polymer: the appearance of hydrolyzed species and protonation of the polymer.

Keywords: Chitosan, Modified Chitosan, Sorption, Uranium, Vanadium, Waste-Water Treatment, Glutamate Glucan, Metal-Ions, Rhizopus-arrhizus, Equilibrium, Removal, Wastes, Adsorption

Sobsey, M.D., Hall, R.M. and Hazard, R.L. (1995), Comparative reductions of hepatitis-a virus, enteroviruses and coliphage MS2 in miniature soil columns. Water Science and Technology, 31 (5-6), 203-209.

Full Text: W\Wat Sci Tec31, 203.pdf

Abstract: The reduction of viruses in wastewater and other contaminated waters in the subsurface or soil environment is an important public health consideration for land disposal of wastes and the use of ground sources as water supplies. Because of the lack of information on the comparative reductions of different viruses in soils receiving wastes, we determined the reductions of hepatitis A virus (HAV), poliovirus 1, echovirus 1 and the indicator virus MS2 in 10-cm deep, miniature soil columns dosed twice weekly with 2.5 cm of water or wastewater and incubated at 5 or 25°C for 16 weeks. The soils studied were coarse sand loamy sand, clay loam and organic muck. By examination of column effluents, few or no viruses were detected in clay loam column effluents, with >99.98% virus reductions under all conditions tested. In organic muck columns virus reductions ranged from 30-98%, with greater reductions at 25°C than at 5°C and greater reductions of enteroviruses than either HAV or MS2. In the sandy soil columns viruses were retained generally better in loamy sand than in coarse sand. Overall, poliovirus was reduced the most and echovirus the least. In coarse sand mean virus reductions ranged from a low of about 50% for echovirus at 5 degrees to a high of about 99.4% for poliovirus at 25 degrees. In loamy sand, mean virus reductions ranged from a low of about 60% for echovirus at 5 degrees to a high of 99.997% for poliovirus at 25 degrees. Virus reductions were greater in sandy soil columns dosed with groundwater than with wastewater. The appreciable breakthroughs of viruses in column effluents of organic muck and coarse sand soils indicate that these soil types may be unsuitable for land application of wastewater under some hydrogeological conditions.

Reynolds, K.A., Gerba, C.P. and Pepper, I.L. (1995), Detection of enteroviruses in marine waters by direct RT-PCR and cell culture. Water Science and Technology, 31 (5-6), 323-328.

Full Text: W\Wat Sci Tec31, 323.pdf

Abstract: Sewage outfalls and storm water runoff introduces pathogenic human enteric viruses into marine coastal waters, which may pose a potential public health risk. Although members of the enterovirus group have been suggested as possible indicators of sewage pollution in marine waters, the lack of rapid, sensitive and cost effective methods have prevented routine monitoring in the United States. This study compared traditional cell culture and direct RT-PCR. (reverse transcriptase-polymerase chain reaction) amplification for detection of an enterovirus. Poliovirus could be recovered from 100 L of artificial seawater with an average efficiency of 77%, using adsorption and elution from electronegative filters. Viruses were eluted from the filters with 1.5% beef extract for viruses (BEV) adjusted to pH 9.5 and reconcentrated by organic flocculation to a volume of 30 mt. Substances which interfered with detection by RT-PCR were removed by treatment of the concentrates with sephadex and chelex resins. Direct RT-PCR could detect 2.5 and 0.025 PFU (plaque forming units) for single (25 cycles) and double PCR (2×25 cycles) in 10 µL of pure culture poliovirus samples, respectively, These methods are currently being applied to assess the occurrence of enteroviruses at marine bathing beaches influenced by sewage discharges.

Keywords: Polymerase Chain-Reaction, Marine Water, Storm Water, Sewage, Enteroviruses, Polymerase Chain Reaction, Cell Culture

Notes: highly cited

? Hsu, K.L., Gupta, H.V. and Sorooshian, S. (1995), Artificial neural-network modeling of the rainfall-runoff process. Water Science and Technology, 31 (10), 2517-2530.

Full Text: 1995\Wat Sci Tec31, 2517.pdf

Abstract: An artificial neural network (ANN) is a flexible mathematical structure which is capable of identifying complex nonlinear relationships between input and output data sets. ANN models have been found useful and efficient, particularly in problems for which the characteristics of the processes are difficult to describe using physical equations. This study presents a new procedure (entitled linear least squares simplex, or LLSSIM) for identifying the structure and parameters of three-layer feed forward ANN models and demonstrates the potential of such models for simulating the nonlinear hydrologic behavior of watersheds. The nonlinear ANN model approach is shown to provide a better representation of the rainfall-runoff relationship of the medium-size Leaf River basin near Collins, Mississippi, than the linear ARMAX (autoregressive moving average with exogenous inputs) time series approach or the conceptual SAC-SMA (Sacramento soil moisture accounting) model. Because the ANN approach presented here does not provide models that have Physically realistic components and parameters, it is by no means a substitute for conceptual watershed modeling. However, the ANN approach does provide a viable and effective alternative to the ARMAX time series approach for developing input-output simulation and forecasting models in situations that do not require modeling of the internal structure of the watershed.

Keywords: Multilayer Feedforward Networks, Back-Propagation, Global Optimization, Approximation, Convergence, Derivatives, Uncertainty, Algorithm, Mappings, Systems

? Oldenburg, M. and Sekoulov, I. (1995), Multipurpose filters with ion-exchanger for the equalization of ammonia peeks. Water Science and Technology, 32 (7), 199-206.

Full Text: 1995\Wat Sci Tec32, 199.pdf

Abstract: In this study the use of zeolites as ion-exchangers for equalization of ammonia peak loadings in aerated biological activated filters was investigated For this use zeolites were mixed with a filter medium and the nitrifying filter was loaded with ammonia peaks for two hours at different flow rates. It could be demonstrated that during the phase of higher inflow concentrations the zeolite was collecting ammonia. When the influent concentration decreased ammonia was desorbed from the zeolite and could be nitrified by the bacteria growing on the biter medium. It was shown that additional zeolites can equalize variations of ammonia, especially in filter units which are working at a high nitrification rate and which are very sensitive to varying influent conditions. During the operation time of the filter no separation of the zeolite by higher hydraulic loading or by backwashing could be recognized. So the upgrading of nitrifying filters with zeolite represents an additional security for effluents containing oscillating ammonia concentrations.

Keywords: Ammonia Peak-Loadings, Filtration, Ion-Exchanger, Nitrification, Zeolites

Zouboulis, A.I., Solari, P., Matis, K.A. and Stalidis, G.A. (1995), Toxic metals removal from dilute solutions by biosorptive flotation. Water Science and Technology, 32 (9-11), 211-220.

Full Text: W\Wat Sci Tec32, 211.pdf

Abstract: Toxic metal ions (cadmium, nickel and zinc), considered as priority pollutants, were removed from dilute aqueous solutions by sorption onto non-living (sterilized) anaerobically digested sewage sludge. The desorption of cadmium from metal-laden sludge was also examined. Flotation was subsequently applied as an effective solid/liquid separation process. The dissolved-air flotation technique was applied for the generation of fine bubbles and, in parallel, electrokinetic measurements were carried out. Promising results were succeeded from the combined process of biosorption/flotation (termed biosorptive flotation).

Nassar, M.M., Hamoda, M.F. and Radwan, G.H. (1995), Adsorption equilibria of basic dyestuff onto palm-fruit bunch particles. Water Science and Technology, 32 (11), 27-32.

Full Text: W\Wat Sci Tec32, 27.pdf

Abstract: Particles prepared from palm-fruit bunch have been used for the adsorption of a basic dye (BR 18) over range of initial dye concentrations and varying adsorbent particle size in the range of 106 to 300 musing batch tests. The results revealed the potential for palm-bunch particles as low cost adsorbents. Uptake of the basic dye was higher at smaller adsorbent particle size. The adsorption isotherm follows both the Langmuir and Freundlich models. Values of the separation factor, R, indicate favourable adsorption for the basic dye palm fruit bunch particles system, that is, 0 < R <1 and Freundlich constant n > 1.

Keywords: Aqueous-Solutions, Bagasse Pith, Removal, Hardwood Palm-Fruit Bunch, Basic Dyes, Particle Size, Adsorption Isotherms

Wahaab, R.A., Lubberding, H.J. and Alaerts, G.J. (1995), Copper and chromium(III) uptake by duckweed. Water Science and Technology, 32 (11), 105-110.

Full Text: W\Wat Sci Tec32, 105.pdf

Abstract: The duckweed Lemna minor was cultivated under laboratory conditions with the amount of incident light as limiting growth factor. The fronds were found to double every 3 days under the highest radiation intensity. The plants were exposed to Cu and Cr(III) solutions of 0.25 and 1.0 mg l^-1 during 10 days. The plants needed to adapt for app. 8 days before attaining maximal, steady state removal. Cr(III) was removed more efficiently from the solution (75-100% in terms of concentration or load reduction) than Cu (35-40%), the higher efficiencies pertaining to the more dilute solutions. Uptake rates were 80-333 and 250-667 mg d^-1 m^-2 for Cu and Cr(III), respectively. The plants accumulated 1-2 g metal kg^-1 plant (dry weight) when exposed to the high concentration. Cu seemed toxic at 1.0 mg l^-1, resulting in plant mortality after 8 days. (C) 1996 IAWQ. Published by Elsevier Science Ltd.

Keywords: Duckweeds, Lemnaceae, Heavy Metal, Chromium, Copper, Uptake, Sewage Treatment, Cadmium

Tünay, O., Kabdasli, I., Orhon, D. and Ates, E. (1995), Characterization and pollution profile of leather tanning industry in Turkey. Water Science and Technology, 32 (12), 1-9.

Full Text: W\Wat Sci Tec32, 1.pdf

Abstract: Leather tanning industry as a significant polluting source is exposed to stringent effluent limitations. On the other hand leather processing has a very complex structure in terms of both production and waste streams. A systematic subcategorization approach is required to assess the pollution characteristics and control measures, In this study, a procedure is defined for the development of subcategories for the industry. Results of a detailed review on the amount and the quality of wastewaters originating from the industry are given and six different subcategories are defined to reflect the structure of the leather processing industry in Turkey, Solid and hazardous waste profiles are also given. Copyright (C) 1996 IAWQ. Published by Elsevier Science Ltd.

Keywords: Agro-Industries, Industrial Pollution, Leather Tanning Industry, Pollution Profile, Subcategorization, Tannery Wastewater Characterization

? Cintoli, R., Di Sabatino, B., Galeotti, L. and Bruno, G. (1995), Ammonium uptake by zeolite and treatment in UASB reactor of piggery wastewater. Water Science and Technology, 32 (12), 73-81.

Full Text: 1995\Wat Sci Tec32, 73.pdf

Abstract: A treatment plant of pre-screened piggery wastewater is tested at lab-scale using Italian zeolites (of very low cost) to strongly reduce the NH₄⁺ from 1500 mg/l to 300-400 mg/l and anaerobic digestion in UASB and UASB-AF reactors to remove organics. The ion-exchange pre-treatment by zeolite leads to a reduction of toxicity of wastewater towards anaerobic microbial population and improves the UASB and UASB-AF reactors yields in organics reduction and gas production, The laboratory plant in this configuration reaches a COD removal range of 60-80% and a good reduction of effluent nutrients concentration whereas the use of a anaerobic second stage gave modest results in organics removal because of low applied organic load. A treatment cycle composed of a pre-treatment with zeolites, anaerobic digestion in UASB-AF reactor and a final treatment in an aerobic activated sludge plant is giving very good preliminary results.

Keywords: Piggery Wastewater, Anaerobic Treatment, Upflow Anaerobic Sludge Blanket, Upflow Anaerobic Sludge Blanket Anaerobic Filter, Zeolites, Nutrients Removal, Design

Lee, S.M., Mathews, A.P. and Nassar, R. (1996), Stochastic modeling of multicomponent adsorption kinetics with non-linear isotherm. Water Science and Technology, 33 (8), 135-143.

Full Text: W\Wat Sci Tec33, 135.pdf

Abstract: A Markov process coupled with the Langmuir adsorption isotherm is developed to simulate bisolute adsorption kinetics. Estimates of all model parameters were obtained from a single-solute experiment for the adsorption of 1,1,1-trichloroethane (TCEA) and trichloroethylene (TCE) from dilute aqueous solutions onto granular activated carbon (GAC). The model verifications indicate that the representation of the rate mechanisms are adequate. The solution of the resultant model equations, which are ordinary differential equations, is simpler than the solution of the partial differential equations involved in the deterministic formulations. This model approach can be extended for the modeling of multicomponent adsorption in fixed-beds.

Gupta, K. and Saul, A.J. (1996), Suspended solids in combined sewer flows. Water Science and Technology, 33 (9), 93-99.

Full Text: W\Wat Sci Tec33, 93.pdf

Abstract: Many studies have identified the first flush phenomenon as being the relatively high concentration of pollutants in the initial phases of combined sewer flow following a storm. One way of controlling the first flush is by the provision of a storage tank such that the effluent can be discharged in a controlled manner. To optimise the storage volume, both the total pollutant load discharged and the temporal variation in pollutant concentration within an event need to be predicted. Sophisticated models to predict the pollutant concentrations in urban sewer flows, for example QSIM and MOUSETRAP are already available. However, the data requirements for these models are extensive, which usually limit their application to major or environmentally sensitive schemes. This paper describes attempts to relate the peak concentration of suspended solids in combined sewer flows to observed storm characteristics. In this study, it was hypothesised that the peak concentrations of suspended solids could be related to the hydrological parameters of maximum rainfall intensity, storm duration and antecedent dry weather period prior to the storm which are commonly used as the basic parameters for urban sewer design. Data from two sites at Great Harwood and Clayton-le-Moors in the North-west of England has been used in the study and an attempt has been made to define an upper limit of the first flush concentration of suspended solids corresponding to storms which have been categorised into bands defined by their peak rainfall intensity.

Anderson, M., Skerratt, R.G., Thomas, J.P. and Clay, S.D. (1996), Case study involving using fluidised bed incinerator sludge ash as a partial clay substitute in brick manufacture. Water Science and Technology, 34 (3-4), 507-515.

Full Text: W\Wat Sci Tec34, 507.pdf

Abstract: Earlier work at Staffordshire University revealed encouraging results when sewage sludge ash from a fluidised bed incinerator was added to a series of common commercial brickclays used in the United Kingdom. The results of this work led a United Kingdom brick manufacturer to the identification of this material as a possible replacement for the sand addition to the bricks produced at one of their factories. As a result, an experimental programme was formulated at Staffordshire University’s Ceramic Technology Laboratory which used the factory’s current mix-design as a control standard against a mix-design in which the sand component was replaced weight-for-weight with sewage sludge ash. Comparative bodies were fabricated and both laboratory and factory firings undertaken. Physical testing results have revealed that the experimental mix-design containing the sewage sludge ash contributes positively to the ceramic properties of the control product in bath the unfired and fired condition. Moreover, the fired colour of this experimental product has also been found to be indistinguishable from the central. Copyright (C) 1996 IAWQ. Published by Elsevier Science Ltd.

Keywords: Ash, Brickmaking, Construction Materials, Fluidised Bed, Incineration, Sludge, Sewage-Sludge, Disposal

Zhang, B. and Yamamoto, K. (1996), Seasonal change of microbial population and activities in a building wastewater reuse system using a membrane separation activated sludge process. Water Science and Technology,