Search results for "Fluent"
showing 10 items of 261 documents
A survey of recent results in passive sampling of water and air by semipermeable membrane devices
1995
Abstract A survey is presented of some recent results for passive sampling of water and air for trace organic contaminants using lipid-filled semipermeable membrane devices (SPMDs). Results of water sampling for trace organochlorine compounds using simultaneously exposed SPMDs and the most universally applied biomonitor (bivalves) are discussed. In general, the total amounts of accumulated analytes available for analysis in bivalves and SPMDs were comparable. However, SPMD controls typically had negligible levels of contamination, which was not always the case for transplanted bivalves, even after prolonged depuration prior to exposure. In surveys of the spatial trends of organochlorines at…
Effects of Pulp and Paper Mill Effluent (BKME) on Physiology and Biochemistry of the Roach (Rutilus rutilus L.)
1996
The effects of bleached kraft pulp and paper mill effluent (BKME) on the roach (Rutilus rutilus L.) were studied under experimental and natural field conditions. In the acute experiment (72 h exposure to the concentrated BKME), the roach suffered from a general stress syndrome, characterized by a significant increase of cortisol and blood glucose, as well as a significant decrease of leucocrit and total plasma protein. In three weeks' exposure in a polluted and an unpolluted lake and in fish caught from the same lakes, the more specific effects of BKME treatments appeared. During the three weeks' exposure, slight hyperglycaemia as well as a decrease in a transaminase activity (GPT) and incr…
Modeling of the effect of EDTA on copper(II) biosorption onto Posidonia oceanica waste in batch and fixed-bed systems
2014
Abstract The performance of Posidonia oceanica for copper(II) biosorption in the presence of EDTA was investigated in batch and column experiments. In batch mode, copper(II) uptake in the presence of EDTA was lower than in its absence for the pH range 1.5–6.0. The decrease in the copper(II) uptake, attributed to the change in the chemical speciation of copper(II) with EDTA in solution, was from 71.7 to 58.8 mg/g in the absence and presence of EDTA respectively at pH 6. Column experiments were carried out at 5 and 20 mg Cu(II)/dm 3 and different doses of EDTA. Constant copper(II) leaks were detected in the effluent of the columns. Leak concentrations matched the copper(II)-EDTA complexes’ co…
RAVITA Technology : new innovation for combined phosphorus and nitrogen recovery
2018
Abstract Present phosphorus (P) recovery technologies mainly contain P recovery from sludge liquor or ash. These types of technologies are suitable for large wastewater treatment plants (WWTPs) with enhanced biological phosphorus removal (EBPR), digestion and/or incineration. In Finland and other Nordic countries, strict P discharge limits require chemical precipitation, thus EBPR alone is not sufficient. Ammonium recovery from wastewater, on the other hand, is not so often discussed. However, recovery from WWTP reject waters would decrease the energy demand of ammonium synthesis by Haber-Bosh technology and the energy demand of the WWTP's biological process. Helsinki Region Environmental S…
Electrochemical technology for the treatment of real washing machine effluent at pre-pilot plant scale by using active and non-active anodes
2018
Abstract Real effluent of washing machine is one of the major sources of microplastics and fabrics in municipal and surface water. The effluents constitute large volume of wastewater with different surfactants since every household and industries nowadays use washing machine rather than traditional hand washing. In this work, a real effluent of washing machine was treated by electrooxidation (EO) in a pre-pilot plant scale electrochemical flow reactor using active (Ti/Pt) or non-active (boron doped diamond (BDD)) anodes and Ti cathode. The effect of anode material (Ti/Pt or BDD) and the applied current density (16.6, 33.3 and 66.6 mA cm−2) on the decay of the organic matter, in terms of che…
Extreme thermophilic (70°C), VFA-fed UASB reactor: performance, temperature response, load potential and comparison with 35 and 55°C UASB reactors
1999
Abstract The paper evaluates the reactor performance, load potential and temperature response of a 70°C, VFAs-fed UASB reactor, seeded with mesophilic granular sludge. Batch experiments were, in addition, conducted to assess the effect of temperature on the achievable residual VFAs in the 70°C effluent. The performance of similarly-fed and seeded 35 and 55°C UASB reactors was also tested. At a short HRT (2–3 h) and a moderate VLR of 12–20 g COD l−1 d−1, the 70°C UASB achieved 66–74% VFAs removal (acetate and butyrate 84–90%, propionate
Natural organic matter coagulation in Valencia water supply. Pilot plant studies
1998
: To reduce disinfection by-product (DBP) formation in drinking water treatment, the presence of natural organic matter in surface waters must be minimised. This paper describes pilot plant studies carried out on two surface waters to assess the effectiveness of coagulation in organic matter removal, the Turia and Jucar rivers, which supply the city of Valencia (1m inhabitants). The experiments were conducted with different coagulants (iron sulphate, polyaluminium chloride (PACl)) and treatment schemes. Process effectiveness was evaluated in terms of effluent turbidity, presence of residual metal in final water, and organic matter removal. Four parameters were used to quantify organic matte…
Wastewater modification processes in a stabilization reservoir: a new mathematical model
2018
The paper presents a mathematical model for the simulation of the ecology of a wastewater stabilization reservoir (WSR). WSRs are hypertrophic aquatic systems devoted to water storage in warm countries where shortage conditions are often encountered. Several factors that affect the stabilization reservoir’s effluent quality were taken into account: hydraulics and hydrology, solar radiation, reaeration, algae, zooplankton, organic matter, pathogens, and sediment-water interactions. The model quantifies the specific influence of each factor on effluent quality, and evaluating the correlation between the different factors. State variables included in the model were: algae, dissolved oxygen, or…
Bleaching of color of kraft pulp mill effluents and natural organic matter in lakes
2002
In situ changes in the color of lake water and biologically treated kraft pulp mill effluents mixed in lake water were examined in three lakes. In 1.7 m3 enclosures, the color (400700 g Pt·m3) of the mixture of pulp mill effluent and lake water remained similar for 4 months in darkness, whereas exposure to solar radiation resulted in 1742% bleaching of color. During the summer stratification of a humic lake, the color (160 g Pt·m3) of hypolimnetic water remained similar to that found during spring turnover, but the color of epilimnion decreased 13%. The measured rates of photochemical bleaching of color by solar radiation could explain the decrease of epilimnetic color. Attenuation of …
Characterization of totally chlorine-free effluents from kraft pulp bleaching III
1999
Abstract Chemical changes in the dissolved high-molecular-mass material from silver birch (Betula pendula) kraft pulp during the oxygen–alkali delignification stage (O) and the subsequent totally chlorine-free (TCF) bleaching sequence (X–Z–EOP–AZ–EP–S) were investigated by analytical pyrolysis (pyrolysis–gas chromatography/mass-sensitive detector (Py–GC/MSD)). In addition, the pyrolysis data were subjected to chemometric analysis, resulting in a rapid method for determining with reasonable accuracy, for example, the mass proportion of carbohydrates and lignin in the effluents from each of the treatment stages. The method was calibrated by chemical analysis on the same effluents.