Search results for "Effluent"
showing 10 items of 235 documents
Electrodialysis Applications in Wastewater Treatment for Environmental Protection and Resources Recovery: A Systematic Review on Progress and Perspec…
2020
This paper presents a comprehensive review of studies on electrodialysis (ED) applications in wastewater treatment, outlining the current status and the future prospect. ED is a membrane process of separation under the action of an electric field, where ions are selectively transported across ion-exchange membranes. ED of both conventional or unconventional fashion has been tested to treat several waste or spent aqueous solutions, including effluents from various industrial processes, municipal wastewater or salt water treatment plants, and animal farms. Properties such as selectivity, high separation efficiency, and chemical-free treatment make ED methods adequate for desalination and othe…
CHEMICAL PULPING. Oxidative degradation of AOX in softwood-based kraft mill effluents from E C F bleachin g
2012
Abstract Softwood-based kraft mill bleaching effluents from the initial bleaching stages D0 and E1 (the bleaching sequence being D0E 1D 1 E2D2) were treated by the oxidative Fenton method (H20rFeS04) to decompose organic pollutants contammg adsorbable organic halogens (AOX). Experiments designed using the Taguchi method were applied to predict the process conditions that would result in a cost-effective and adequate removal of AOX. In addition to the composition and concentration of the reagents (H202 and Fe2+), the main process parameters selected were temperature and reaction time, while pH was adj usted to an approximate value of 4 (the volumetric ratio of the mixed effluents D0:E 1 was …
A LASER-INDUCED FLUORESCENCE (LIF) METHOD FOR MONITORING OXYGEN–ALKALI DELIGNIFICATION OF SOFTWOOD KRAFT PULP
2002
ABSTRACT A laser-induced fluorescence (LIF) method for monitoring the oxygen–alkali delignification of pine (Pinus sylvestris) kraft pulp was tested. The fluorescence intensity of the effluent was found to increase systematically during treatment as the lignin content of the pulp decreased. This emission method, compared, for example, to a UV/Vis absorption method, seems to have potential for large-scale applications. Owing both to the complex chemical nature of the effluent from oxygen–alkali delignification and to the complex nature of the fluorescence method, further work on this method is needed before it can be used for industrial purposes.
Comparison of laboratory-scale thermophilic biofilm and activated sludge processes integrated with a mesophilic activated sludge process
2003
A combined thermophilic-mesophilic wastewater treatment was studied using a laboratory-scale thermophilic activated sludge process (ASP) followed by mesophilic ASP or a thermophilic suspended carrier biofilm process (SCBP) followed by mesophilic ASP, both systems treating diluted molasses (dilution factor 1:500 corresponding GF/A-filtered COD (COD(filt)) of 1900+/-190 mgl(-1)). With hydraulic retention times (HRTs) of 12-18 h the thermophilic ASP and thermophilic SCBP removed 60+/-13% and 62+/-7% of COD(filt), respectively, with HRT of 8 h the removals were 48+/-1% and 69+/-4%. The sludge volume index (SVI) was notably lower in the thermophilic SCBP (measured from suspended sludge) than in …
Treatment of Gaseous Effluents Produced During Electrochemically Assisted Soil Remediation Processes
2021
In many cases, electrochemically assisted soil remediation processes, like electrokinetic or electroheating ones, produce gaseous effluents that need to be collected and treated. Adsorption, absorption, and catalytic and thermal oxidation are often used for the treatment of these gaseous effluents. The chapter describes these technologies reporting their main advantages and disadvantages. Eventually, a comparison of the performances of these technologies was carried out.
Fermentation and elutriation of primary sludge: Effect of SRT on process performance
2007
Abstract A primary sludge fermentation–elutriation pilot plant was operated using in-line and side-stream schemes. The influence of solids retention time, recirculation sludge flow-rate and solids concentration on the fermentation–elutriation process performance has been assessed in this paper. The use of high elutriation flows (12% of influent flow) improved the volatile fatty acids (VFA) concentration in the effluent stream. Suspended solids removal efficiency decreased in the primary settler when the solids retention time (SRT) was increased from 4 to 8 days. Disintegration step during hydrolysis process was pointed out as the main reason for that decrease. Maximum VFA productions were a…
A preliminary investigation of total organic carbon variation in influent and effluent of Isfahan (Iran) water treatment plant, urban network and Fel…
2006
In this work a series of total organic carbon (TOC) analyses were carried out to analyse the influent and the effluent of a water treatment plant providing Isfahan city in Iran. Other analyses were focused on the determination of TOC in the urban network and Fellman wells (in Isfahan and Dehaghan cities), in order to compare the water quality soon after the treatment with that of circulating water in the city network. Since it supplies water treatment plant, TOC content of Zayandehrood River was also compared with the treated water. The obtained results revealed that there were significant differences between TOC content of effluent of water treatment plant and that of the urban network (ma…
Vertical distribution of pharmaceuticals in lake sediments-citalopram as potential chemomarker
2012
The use of pharmaceuticals has increased enormously over the last few decades and serious concerns about their environmental fate and effects have arisen. Thus far, there is little knowledge about the historical pollution of the environment by pharmaceuticals. In the present study, sediment columns from three lake sites adjacent to wastewater treatment plants were collected, further divided in 2- or 2.5-cm slices, and analyzed for 15 pharmaceuticals by liquid chromatography-tandem mass spectrometry. In addition, sediment columns were historically interpreted by analyzing fecal sterols (coprostanol and cholesterol) as well as organic material and organic carbon. Several pharmaceuticals were …
The occurrence and bioavailability of retene and resin acids in sediments of a lake receiving BKME (bleached kraft mill effluent)
1999
Retene (7-isopropyl-1-methylphenantrene) is an alkyl substituted PAH derived primarily from bacterial aromatization of abietic type resin acids. Retene has been shown to induce cytochrome P450 1A in rainbow trout whereas e.g. dehydroabietic acid does not induce it. We analysed resin acids and retene in sediments from seven sites receiving pulp and paper mill effluents from 4 mills, and from two reference sites. All mills have employed treatment of waste waters by activated sludge. The highest concentration of retene measured in sediment was 1600 μg/g d.w. (11 700 μg/g organic carbon, OC) while the highest concentration of resin acids was 1500 μg/g d.w. (9 300 μg/g OC). Downstream from the p…
Occurrence of retene and resin acids in sediments and fish bile from a lake receiving pulp and paper mill effluents
1999
Retene (7-isopropyl−1-methylphenanthrene) is a dialkyl-substituted PAH derived thermally and microbially from dehydroabietic acid. We have analyzed for retene and several resin acids in sediments at five depths at several sites in a lake receiving effluents from three pulp and paper mills, and two upstream reference sites. The highest concentration of retene was 1,600 μg/g dry weight (11,700 μg/g organic carbon [OC]) and of total resin acids was 1,500 μg/g dry weight (9,300 μg/g OC). Twelve kilometers downstream from the point of bleached-kraft mill effluent (BKME) discharge, the concentration of retene at a depth of 5 to 10 cm was 16 μg/g dry weight (650 μg/g OC) and of resin acids was 139…