Showing papers in "Water Research in 1993"

TL;DR: In this paper, a study on the physico-chemical structure of activated sludge flocs was carried out to get a better insight in its relationship with sludge settleability.

TL;DR: In this article, it was shown that sphagnum moss peat, which is essentially oligotrophic, in concentrations ranging from 4 to 40 g/l can be used effectively to remove hexavalent chromium from aqueous solutions.

TL;DR: Ozonation experiments in a multiple reactor system were conducted to investigate the efficiency of this process in reducing the color and chemical oxygen demand of the textile waste effluents as mentioned in this paper.

TL;DR: In this paper, the theoretical basis of the methods allowing to determine and calculate methanogenic and non-methanogenic sludge activities in anaerobic digesters is examined and accordingly, proper experimental conditions are established.

TL;DR: In this paper, the amount of organic matter taken up by the phosphorus accumulating bacteria during the anaerobic phase affects the total denitrification rate, as well as the rate at which the organisms take up phosphate under anoxic conditions.

TL;DR: The competition between polyphosphate accumulating bacteria (PP bacteria) and another group of microorganisms (tentatively named “G bacteria”) has been observed in laboratory sequencing batch reactors exhibiting enhanced biological phosphate removal (EBPR).

TL;DR: In this paper, a rapid physical-chemical method was developed for the determination of the readily biodegradable portion of influent soluble COD, which involves removal by flocculation and precipitation of colloidal matter that normally passes through 0.45 μm membrane filters.

TL;DR: In this article, the potentials of digested sludge to reduce nitrate and nitrite in the presence of five different carbon sources: glucose, glycerol, acetic acid, lactic acid and methanol were determined.

TL;DR: Field and laboratory studies were conducted to develop and verify the kinetic expressions and attendant coefficients required to simulate the loss of fecal coliform bacteria in lakes due to death [as mediated by irradiance (light) and temperature] and sedimentation.

TL;DR: Physical and chemical characteristics of activated sludge such as floc size, density, specific surface, carbohydrate content, dehydrogenase activity and settleability were investigated by seven parallel bench scale activated SLudge units operated under different sludge ages (1.1-17.4 days) as mentioned in this paper.

TL;DR: In this article, the authors used activated carbon prepared from bicarbonate-treated peanut hulls (BPHC) for the adsorption of Hg(II) over a range of initial metal ion concentrations (10−20 mg dm−3), agitation time (5−180 min), adsorbent dosage (5-120 mg 100 ml−1) and pH (1.5−10.0).

TL;DR: In this paper, a method of chemical treatment is discussed which has been very effective to remove the fluoride ion from effluent to a concentration of 1.5 mg 1−1 or less (which is disposable) by precipitation technique followed by complexation.

TL;DR: Algal blooms which contained Microcystis aeruginosa almost always had detectable concentrations of microcystin-LR, a peptide hepatotoxin, based on high performance liquid chromatography (HPLC) analyses, and among three lakes studied in greater detail, the concentration ofmicrocystIn-LR present in the blooms was highly variable between lakes and temporally within each lake over the limited sampling period.

TL;DR: In this paper, the authors examined the possible use of fly ash, a byproduct of coal power stations, as a means of removing arsenic from water, or equivalently, of restricting its movement in the solid wastes or the soil.

TL;DR: In this article, the hydrolysis kinetics of Reactive Blue 19-Vinyl Sulfone (RB 19-VS) were studied in phosphate buffer over a pH range of 4-11 and a temperature range of 25-85°C.

TL;DR: The acute and chronic toxicity of nonylphenol to the freshwater invertebrate Daphnia magna has been determined in this article, where the acute 24 and 48 h EC 50 values, based on immobilization, were 0.30 and 0.19 mg/l, respectively, using mean measured concentrations.

TL;DR: In this article, the composition of anaerobic granules and their EPS was investigated when the granules were exposed to long term depletion of selected heavy metals (Ni, Co and Fe) in upflow sludge blanket (UASB) reactors.

TL;DR: In this paper, the influence of bicarbonate/carbonate ions and a commercial humic substance on the oxidation rate of atrazine in water has been observed, and the quantum yield and hydroxyl radical reaction rate constant of the acid was found to be 0.05 mol photon −1 and 1.8 × 1020M−1s−1, respectively.

TL;DR: In this paper, the authors investigated loss of polynuclear aromatic hydrocarbons (PAH) while attempting to bioremediate soils from a manufactured gas plant (MGP) site.

TL;DR: In this article, the authors used GC-MS and HPLC to identify six haloacetic acids, in which four of them containing bromine, in Lake Kinneret (Lake Galilee) water.

TL;DR: In this article, the effects of chromium, cadmium, lead, copper, zinc and nickel on volatile fatty acid (VFA) production in anaerobic digestion were studied using serum bottle assays.

TL;DR: In this paper, the possibility of using ground, dried and classified Pinus sylvestris bark for trivalent chromium removal in tannery wastewater polishing was studied.

TL;DR: In this article, a generalized expression for chlorine consumption at the pipe wall is used to solve the governing equation and to determine the average chlorine concentration at any location in the pipe, and a methodology to determine them in pipe networks is proposed.

TL;DR: In this paper, the potential adsorption constants (k am ) measured reveal a metal affinity sequence Hg > Cd > Ni, in partial contrast to the metal toxicity (MT) one.

TL;DR: In this article, the phytotoxic effect and uptake capacity of Zn, Cr and Cd by the water hyacinth Eichhornia crassipes were investigated in a greenhouse.

TL;DR: In this paper, an advanced monitoring system for controlling the treatment process of wastewater containing chromium(VI) was developed using a flow method as a chemical sensing probe, which is computer-controllable.

TL;DR: A quantitative survey of the protozoan microfauna at 17 activated sludge plants, has been carried out and revealed a clear relationship between the presence and abundance of some species and the prevailing environmental factors and plant operating conditions.

TL;DR: The interaction between denitrification and methanogenesis, with methanol functioning as an electron donor, has been examined through usage of a mixed culture system of denitrifying sludge and mixtures of methanogenic sludge in an anaerobic bioreactor.

TL;DR: In this article, the effect of polyethylene glycol (PEG) on the horseradish peroxidase (HRP) catalysed removal of phenol from wastewater has been studied over the phenol concentration range of 1-10 mM (0.1-1.0 g/l).

TL;DR: The enzyme catalyzed polymerization process was implemented in a continuous stirred tank reactor (CSTR) configuration because reactant and enzyme concentrations are lowered immediately upon entering the reactor causing a reduction in inactivation of HRP through free radical bonding and compound III formation.