Showing papers in "Water Research in 1990"

TL;DR: Gross chemical analysis of these extracted polymers suggests that anaerobic and activated sludge polymers do differ, with protein being the most dominant fraction in an aerobic samples compared with carbohydrate in the latter.

TL;DR: It was shown in this study that ion-exchanger cartridges can leach detrimental substances into the matrix water and only ultrapure matrix waters should be used for the preparation of culture media.

TL;DR: In this article, the chemistry of Al coagulants is investigated and the results suggest that when using alum, some of the adverse effects of low temperatures may be mitigated by an increase in pH, thereby maintaining a constant concentration of the complexing ligand, OH −.

TL;DR: A more rigorous approach is required to gain insight into the geochemistry of trace elements or their bioavailability as discussed by the authors, which is needed to determine the speciation of trace element in sediments.

TL;DR: In this article, the removal of Omega Chrome Red ME (a popular chrome dye) from its aqueous solutions by adsorption on a homogeneous mixture of fly ash and coal in different proportions has been carried out.

TL;DR: In this paper, the authors showed that a sand column with immobilized S. cerevisiae can be stripped of adsorbed Cu(II) with one volume of acid (5 × 10−3 M HClO4) per 20 volumes of solution.

TL;DR: In this article, a mixed-flow RL with DO (dissolved oxygen) control was operated at 25°C using substrate containing 80 mg l−1 of NH3-N. Determination of the biomass index based on the substrate utilization rate revealed that low levels of DO elevated the growth yield of ammonia oxidizers by double.

TL;DR: In this article, a functional relationship for the simultaneous dependence of the effective maximum specific growth rate (μA) minus the decay coefficient, bA) on temperature and pH, obtained from theoretical arguments, was verified via batch experiments with sludge from a local wastewater treatment plant.

TL;DR: A portable reverse osmosis (RO) system was constructed and used to concentrate dissolved organic matter (DOM) from the Suwannee River in southeastern Georgia as mentioned in this paper, where a very high percentage of DOM was recovered, which indicates minimal fractionation of the original sample.

TL;DR: In this article, an experimental procedure for the determination of photonic fluxes at 253.7 nm emitted by low-pressure mercury vapour lamps and for the evaluation of the reflecting power of the internal wall of photochemical reactors was described.

TL;DR: In this article, the contents and speciation of Zn, Cd, Pb, Cu, Ni and Co in sediments taken in the Pisuerga river, that flows through the town of Valladolid and is polluted by industrial and municipal effluents.

TL;DR: In this paper, the authors used the Langmuir-Hinshelwood (L-H) kinetics for each solute to predict the mineralization rate at any solute concentration in aerated, aqueous suspensions of TiO 2 with near uv light.

TL;DR: In this article, surfaces of electropolished, bright annealed and matt stainless steel and of lead stabilized PVC were exposed to running municipal drinking water (10 cm s−1) for 167 days and the total number of micro-organisms growing on the surfaces was examined with an acridine orange direct count technique at 7 sampling times.

TL;DR: In this paper, the development of a better system for indexing water quality and its application to four water use classes are described, including bathing, water supply, and fish spawning.

TL;DR: In this article, the effect of the activity of heterotrophs on nitrification was examined in laboratory scale reactors at 25°C with various concentrations of glucose, and the results clearly indicate that the addition of organic matter, which provokes the growth of heterots, inhibits ammonia oxidation.

TL;DR: In this paper, an experimental artificial wetland is described together with a mass balance method for quantifying system performance, major nutrient storage components and nutrient removal mechanisms, and overall system performance could be described by a simple first order, steady state model.

TL;DR: In this article, the coagulation of fulvic acid (FA) by alum and polyaluminum chloride (PACI) is examined and an Al speciation methodology was used to examine complexation reactions between Al and FA for water treatment conditions.

TL;DR: In this paper, a stirred batch system with the use of two Ti electrodes and direct current, the polarity of which alternated automatically in half cycles of 1 min, was found to be effective and the percentage of the initial concentration of bacteria which were destroyed was proportional to both treatment time and the square of current density.

TL;DR: Samples collected from 102 sites in Wisconsin indicate that algal toxins may be more serious environmental hazards than generally recognized.

TL;DR: In this paper, the behavior and diurnal load variations of nitrilotriacetate and ethylenediaminetetraacetate (EDTA) were investigated in winter and in summer in the sewage treatment plant Zu¨rich-Glatt.

TL;DR: In the Scenedesmus cell multiplication inhibition test, 68 potentially hazardous substances were examined to determine the effect concentrations (EC). The tests were conducted in accordance with the test procedure DIN 38 412, Part 9 (draft standard) as discussed by the authors.

TL;DR: In this article, the authors used data on individual species to determine the possible adverse effects of saline wastewater discharges on aquatic ecosystems, in particular lowland rivers and streams and wetlands.

TL;DR: The decomposition processes of organic matter during winter in a 3-year old soil-based constructed reed bed with lateral sub-surface water flow were evaluated by quantifying the in- and efflux of metabolic gases and by considering input-output budgets and relating these to storages within the bed.

TL;DR: The factors affecting the measurement of electron transport system (ETS) activity in river biofilm through the reduction of 2-(p-iodophenyl)-3-(p-,p-nitrophenyl)-5-phenyl tetrazolium chloride (INT) to iodonitrotetramolium formazan (INT-formazan) have been studied.

TL;DR: In this paper, a batch of soil microcosms were used to evaluate the sorption and bioavailability of toluene in an organic soil containing acclimated bacteria, and it was shown that a small amount of tofluene desorbs very slowly and becomes available for biodegradation at a rate limited by desorption.

TL;DR: In this article, the authors showed that the higher the initial cupric concentration, the more important is this complexation reaction, and that the ion exchange sites were relatively saturated and reached 308 and 101 mmol/kg d.w.

TL;DR: In this paper, the uptake of lead and zinc by Azolla pinnata R.Br. (water velvet) and Lemma minor L. (duckweed) was investigated in solutions, enriched with 1.0 and 8.0 mg/l of these two metal ions, which were renewed on alternate days over a 14 day test period.

TL;DR: In this paper, a procedure of sequential extraction steps proposed by Psenner et al. to quantify ecologically relevant phosphate fractions in lake sediments has been applied to activated sludge from waste treatment plants for biological phosphate removal.

TL;DR: In this paper, the interactions of Cu(II) with algal surfaces and exudates were studied in metal-NTA buffers by a combination of several analytical techniques, and the results were interpreted in terms of conditional equilibrium constants valid at a given pH.

TL;DR: In this article, an approximate form of the coprecipitation equation was developed and tested using data from studies of coprecIPitation kinetics in different river waters, and the results indicated that within certain limits of pH and phosphate concentration, the simplified equation described the adsorption function and hence coprecipient behaviour reasonably well, i.e. within 10% of the value obtained using the full form.