Showing papers in "Water Science and Technology in 1997"

TL;DR: In this article, the authors summarized how macrophytes influence the treatment processes in wetlands and concluded that the most important functions of the macrophyte in relation to the treatment of wastewater are the physical effects the presence of the plants gives rise to.

TL;DR: In this paper, four low-cost adsorbents, namely peat, steel plant slag, bentonite clay and fly ash, were used for dye removal from wastewaters.

TL;DR: In this paper, a general hypothesis explaining polymer formation is developed, and the advantages and disadvantages of this formation of storage polymers for the operation of SBR processes is discussed. But the authors do not consider the use of polyhydroxyalkanoates in the SBR process.

TL;DR: The maximal hydrogen production potential by anaerobic bacteria is 1.3 to 2.2 mol-H2/mol-glucose, which is less than 50% of theoretical, and the fatty acid production from the vacuum cultures exhibited approximately the same yield of fatty acids as those of the non-vacuum cultures.

TL;DR: In this article, a new concept is discussed along general lines, which consists of a first stage in which a maximal sludge production is achieved, in this way COD is removed as sludge and aeration requirements minimized.

TL;DR: In this article, the effect of ultrasound pretreatment on sludge degradability was investigated using ultrasound at a frequency of 31 kHz and high acoustic intensities, which resulted in raw sludge disintegration as was demonstrated by increase of Chemical Oxygen Demand in the sludge supernatant and size reduction of sludge solids.

TL;DR: A conceptual biofilm model taking into account microbial physiology with regard to production of extracellular polymers and their transformation within the biofilm is suggested and can be helpful in structuring the design and evaluation of biofilm experiments focusing on biofilm structure and properties.

TL;DR: In this paper, the effects of pretreatment on the anaerobic digestion of waste activated sludge (WAS) were investigated in terms of VSS solubilization and methane production by batch experiments.

TL;DR: A combination of both kinds of processes would mean a cheaper option for total organics degradation from a toxic wastewater as discussed by the authors, however, total mineralisation through this means is very expensive and there are substances, however, which they are unable to deal with.

TL;DR: In this paper, the authors present a brief review of key processes regulating pollutant removal and identify potential indicators that can be measured to evaluate treatment efficiency, such as carbon and toxic organic compound removal efficiency can be determined by measuring soil or water oxygen demand, microbial biomass, soil Eh and pH.

TL;DR: In this article, the authors measured physical characteristics of solids transported in lateral pavement sheet flow from a heavily traveled urban roadway in Cincinnati and sorted solids according to particle size distributions.

TL;DR: The IERECHROM (Ion Exchange Recovery of CHROMium) process as discussed by the authors was developed for removal, recovery and reuse of Cr(III) ionic complex from segregated tannery wastewaters, based on the use of a weak electrolyte macroporous carboxylate resin, retaining the metal of reference together with other trace metals, including aluminum and iron.

TL;DR: A risk assessment approach was developed to arrive at a comparative risk analysis of the various recommended wastewater irrigation microbial health guidelines for unrestricted irrigation of vegetables normally eaten uncooked, and preliminary estimates show that meeting the USEPA Guidelines would result in an extra expenditure of $3–30millions/case of disease prevented.

TL;DR: In this paper, sustainable technology leads to acceptable gradients in state variables, which will lead to a minimal increase of entropy and will require an active rather than a reactive approach, and an example is introduced which deals with global cycling of nutrients and which may be approached on a regional scale.

TL;DR: In this article, a combination of simultaneous ultrasound and alkaline pretreatment is proposed to enhance the production of volatile acids in WAS in order to achieve recovery of volatile fatty acids from the WAS.

TL;DR: In this paper, the effect of temperature and pH on the adsorption isotherm of cadmium on activated carbon was investigated and it was found that the effect is a strong function of pH and temperature.

TL;DR: Results demonstrate that some azo dyes could serve as a carbon, energy, and nitrogen source for anaerobic bacteria.

TL;DR: By integrating the anaerobic process with other biological methods (sulphate reduction, micro-aerophilic organisms) and with physical-chemical methods, a complete treatment of the wastewater can be accomplished at very low costs, while at the same time valuable components can be recovered for reuse.

TL;DR: In this article, the efficiencies of the various OH radical sources can be experimentally quantified and compared when they are calibrated by following the oxidation of inter-calibrated reference compounds that react during the process only with OH radicals.

TL;DR: The aim of this study was to determine the rate at which C parvum oocysts, E coli , faecal enterococci and C perfringens spores die in surface water and the influence of temperature and the presence of autochthonous (micro)organisms on the die-off rate.

TL;DR: In this paper, a review of the literature on clogging in sand filters is given, and it is shown that clogging occurs only in the upper 0-15 cm of the bed.

TL;DR: In this article, the photo assisted Fenton reaction (Fe(II)+H2O2) with UV light was investigated for the treatment of landfill leachate, and an experimental set-up was established to establish the optimal treatment conditions.

TL;DR: In this article, an activated sludge process which produces no excess sludge was developed, which is very simple as a small amount of return sludge is ozonated and then returned to the aeration tank.

TL;DR: In this article, the amounts and concentrations of nutrients and heavy metals in urine solution from a source separating sewage system were measured, indicating that the system did not have any large nitrogen loss.

TL;DR: In this paper, a simple diffusion-reaction model was proposed to describe the measured data, and the influence of operational parameters was evaluated in order to establish ways to affect the NO 2 − concentration.

TL;DR: In this article, a systematic procedure for selecting identifiable parameter subsets for a given set of measured outputs is proposed, where the aim is to only select those parameters which can be estimated uniquely from the dataset used.

TL;DR: In this article, the authors used artificial and real textile secondary effluents to evaluate the COD and color removal efficiencies for ferrous coagulation and Fenton's preoxidation process.

TL;DR: The leachate treatment plant of the landfill in Mechernich including biological pretreatment, reverse osmosis and evaporation and drying of the concentrate has been in operation since the beginning of 1994 as mentioned in this paper.

TL;DR: In this paper, the authors discuss the limitations of aid programmes from donor countries and the need for in-house research, training and development of constructed wetlands for water purification in developing countries.