bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isotopic and Diatom Evidence of Bacterial Sulphate Reduction in Sediments
Authors: Rao S. S. , Dickman M. D. , Thode H. G. 
Published: March 2019

Abstract
Sulphur contents and sulphur isotope ratios (δ34 So/00 values) in deep sediments (10–12 cms; circa 50–100 years before the present) and surface sediments (0–2 cm; circa 0–10 years before the present) from eight lakes located north of Lake Superior, Canada indicated that surface sediments had a significantly higher sulphur content (largely organic sulphur) per gram dry weight and a lower sulphur isotope ratio than the deeper layers.
The increased sulphur content and decreased sulphur isotope ratios (δ34 S0/00 values) in the surficial sediments were much greater for the lakes near and downwind from the Wawa sintering plant than for more remote lakes reflecting the impact of the sintering plant emissions on the lake environment.
A significant relationship was observed between the sulphate reducing bacterial populations and the magnitude of the isotope shift in the study lakes. It was evident from the data that the greater the abundance of sulphate reducers the greater was the surface sediment sulphate content and the degree of isotope fractionation in the anaerobic and organic rich sediments. The surface sediments of the eight study lakes revealed isotopic evidence of bacterial sulphate reduction. The deeper sediments, however, did not reveal such a condition due to the absence of sulphate reducers.
The rate of lake acidification as inferred from the downcore diatom inferred pH profile for each of the study lakes was not significantly correlated with the amount of sulphur in the lake sediments, nor was it correlated with the density of sulphate reducing bacteria or shifts in the sulphur isotope ratios (δ34S).
Use of a Chi-Squared Procedure for Comparison of Complex Gas Chromatograms
Authors: Rodger C. E. , Huck P. M. , Daignault S. A. , Williams D. T. 
Published: March 2019

Abstract
This paper describes the use of a statistical technique involving the chi-squared test to assist in the interpretation of broad spectrum gas chromatographic data.
The GC data were collected during the operation of a pilot plant which examined in parallel four alternative drinking water disinfectants – chloramines, chlorine, chlorine dioxide and ozone. Treatment process samples were obtained by passing water through XAD-2 resin which was then extracted and the extracts concentrated and used for GC analysis and mutagenicity testing. The pilot plant treated three seasonally distinct types of water-winter, spring thaw and spring-summer.
A large number of XAD-2 adsorbable and gas chromatographable organic compounds were present in the raw water, producing chromatograms having a large number of peaks. Oxidant addition resulted in some change in the chromatograms, but the basic fingerprint remained largely unaltered. The chi-squared technique was used to make semi-quantitative comparisons of the chromatograms over time and among the four oxidants. Chromatograms showing abnormal peak counts often corresponded to mutagenic or toxic events.
Lake Renewal Rate and Water Quality Implications
Authors: Kudelska Danuta M. 
Published: March 2019

Abstract
Water exchange in lakes reflects on their trophic status and has implications on water quality. However, in contrary to common belief, beneficial effects of dilution or ‘flushing’, due to high hydraulic load, should not be expected in the case of polluted tributaries. Research conducted in Poland on several hundred lakes indicated, that 80% of lakes with intensive water renewal rates, (200%/y to 21400%/y) were characterized with bad water quality. Those lakes with low, (30% or less) water renewal rate per annum mostly had good or even very good water quality. Inferior water quality of lakes having low water renewal rate was usually associated with the presence of point sources of pollution. Contribution from the tributary sources would improve the lake water quality only if reduction of the loadings to the rivers is achieved through watershed pollution control.
Reductive Dehalogenation of Environmental Contaminants: A Critical Review
Authors: Baxter R. M. 
Published: March 2019

Abstract
It is generally recognized that reductive processes are more important than oxidative ones in transforming, degrading and mineralizing many environmental contaminants. One process of particular importance is reductive dehalogenation, i.e., the replacement of a halogen atom (most commonly a chlorine atom) by a hydrogen atom.
A number of different mechanisms are involved in these reactions. Photochemical reactions probably play a role in some instances. Aliphatic compounds such as chloroethanes, partly aliphatic compounds such as DDT, and alicyclic compounds such as hexachlorocyclohexane are readily dechlorinated in the laboratory by reaction with reduced iron porphyrins such as hematin. Many of these are also dechlorinated by cultures of certain microorganisms, probably by the same mechanism. Such compounds, with a few exceptions, have been found to undergo reductive dechlorination in the environment.
Aromatic compounds such as halobenzenes, halophenols and halobenzoic acids appear not to react with reduced iron porphyrins. Some of these however undergo reductive dechlorination both in the environment and in the laboratory. The reaction is generally associated with methanogenic bacteria. There is evidence for the existence of a number of different dechlorinating enzymes specific for different isomers.
Recently it has been found that many components of polychlorinated biphenyls (PCBs), long considered to be virtually totally resistant to environmental degradation, may be reductively dechlorinated both in the laboratory and in nature. These findings suggest that many environmental contaminants may prove to be less persistent than was previously feared.
Developments in Legislation Related to Treatment of Petroleum Refinery Effluents: A Canadian Overview
Authors: Putnam David L. 
Published: March 2019

Abstract
Public concern over toxic contaminants in drinking water and the environment in general has put increasing pressure on governments to develop and enforce stringent environmental regulations. An overview of developments in Canadian federal and provincial legislation related to the regulation of petroleum refinery effluent quality is provided. Current knowledge of Canadian petroleum refinery effluent quality and level of treatment is summarized.
Current Practice for Treatment of Petroleum Refinery Wastewater and Toxics Removal
Authors: Dold P.L. 
Published: March 2019

Abstract
Current practice and experience in the treatment of petroleum refinery wastewater is reviewed briefly, with emphasis on the fate of toxic contaminants. The sources and composition of the wastewater are described in terms of the parameters adopted for evaluating the performance of individual treatment units. The parameters include oil and grease content and sulphide concentration for evaluating the primary treatment units: sour water stripping, API separation and dissolved air flotation (DAF). COD, BOD, suspended solids and “listed” trace contaminant concentrations are considered in the description of biological activated sludge secondary treatment. Current treatment technology achieves a significant reduction in toxic contaminants and other pollutants generated in the petroleum refining process, with the principle reduction occurring in the activated sludge system. The removal mechanisms considered in activated sludge are biological degradation, nitrification, stripping of VOC’s, biosorption, bioaccumulation of heavy metals and heavy metal precipitation. A number of potential problems associated with activated sludge treatment are identified; amongst others, high effluent COD’s, presence of toxic contaminants (at low concentrations) in the treated effluent, inhibition, poor sludge settleability, and waste sludge disposal.
Management and Analysis of Data from Petroleum Refinery Wastewater Treatment Plants
Authors: Chapman David T. , Grammas Jerry 
Published: March 2019

Abstract
An overview is provided of the main issues which must be addressed in managing and analyzing data from wastewater treatment facilities. The objectives of environmental data management and analysis are discussed from the point of view of both the plant operator or owner and the regulatory authority. Based on the examination of the 1985 records of flow and phenol concentrations from seven Canadian petroleum refineries, recommendations are made for improving existing databases. In analyzing environmental data to transform raw data into information, exploratory data analysis techniques should be used by engineers or operators who do not have formal statistical training. These methods employ simple statistical summaries and graphical data displays. The paper concludes with a brief discussion about future trends in environmental data management and analysis. An extensive statistical background on the part of the reader is not assumed.
Control Systems for the Activated Sludge Process Part I — Modelling
Authors: Vitasovic Zdenko , Andrews John F. 
Published: March 2019

Abstract
An integrated dynamic model and control system are presented for the activated sludge process. The integrated model is comprised of separate models for the influent pump station, air supply and distribution system, biological reactor, and solids-liquid separator. The models for the pump station and for the air supply and distribution system were based on those for a full-scale plant, the Sagemont plant, Houston, Texas, and use standard engineering equations. The models for the biological reactor and solids-liquid separator are more research oriented and were obtained primarily from the literature. Predictions using these models are therefore expected to be more qualitative than quantitative. The integrated model will be used in part II of the paper to explore process control strategies by computer simulation.
Reactions of Hydroxyl Radicals with Chlorobenzenes: Comparison of TiO2 Photocatalyst Reactions to Fenton’s Reagent
Authors: Lepore G. , Langford C.H. 
Published: March 2019

Abstract
A comparative study on reactions of solution and surface generated hydroxyl radicals with chlorobenzenes has been carried out, to determine the reaction path of reactive intermediates in photo-catalysis. Two separate approaches for generating hydroxyl radical oxidants in aqueous media were employed. Fenton’s reagent (solution generation) and TiO2 irradiation (surface generation) were exploited in the decomposition of dichlorobenzenes, 1,2,4-trichlorobenzene and a mixture (o-DCB, m-DCB, 1,2,4-TCB). Photocatalysis displayed a distinctive order for the individual chlorobenzenes with increasing ease of disappearance: p-DCB &lt; 1,2,4-TCB &lt; o-DCB &lt; m-DCB. Reduced selectivity was observed for a mixture. Use of Fenton’s reagent resulted in the following pattern for both individual and the mixture of chlorobenzenes: 1,2,4-TCB &lt; o-DCB ≈ p-DCB ≈ m-DCB. Added acetone, suppressed the disappearance of the parent chlorinated aromatics in both systems. However, in the reaction with Fenton’s reagent 1,2,4-TCB displayed considerable sensitivity in comparison to the DCB isomers. In contrast, the photocatalysis of three individual substrates evaluated in a mixture (1,2,4-TCB, m-DCB, o-DCB) did not manifest significant differences. Results indicate that reactions observed on the photocatalyst must occur in the adsorbed state, where the oxidant is an adsorbed hydroxyl radical or the surface trapped hole itself.
Design and Operation of a Pilot Plant for the Evaluation of Disinfection By-Products in Drinking Water
Authors: Milne G.D. , Harris D.I. , Irvine G.A. , Kellendonk D.I. , Huck P.M. 
Published: March 2019

Abstract
Throughout the water treatment industry, a significant amount of research has recently focused on evaluating the effects of trace levels of contaminants on drinking water quality. This paper describes a pilot plant consisting of a common initial treatment sequence followed by four independent parallel streams, which was built for a study which evaluated the potential of various disinfectants to form mutagenic compounds. Chemically inert materials (glass, stainless steel and fluorocarbons) were used throughout for all water contacting surfaces in the pilot plant. The plant was subsequently modified to study the effects of ozonation and biological activity in anthracite-sand and granular activated carbon (GAC) filters on the formation and removal of easily biodegradable or assimilable organic carbon (AOC).
This paper outlines the design approach, provides a detailed process description and discusses experimental methods, costs, operating criteria and typical process performance and problems associated with this pilot plant.
Economic Analysis of Electroplating Discharges to Sewage Treatment Plants
Authors: Looker Norman D. , McBean Edward .A. , Farquhar Grahame J. 
Published: March 2019

Abstract
A comparison of costs of implementing an advanced wastewater treatment system for a cadmium plating plant, versus the sludge disposal costs of the sewage treatment plant to which the plating plant is discharging its effluent, is described. An economic analysis spreadsheet approach using Lotus 1-2-3 is employed. A case study application demonstrates for overall society net benefit that it is cost-effective to initiate pretreatment at electroplating facilities which allows a municipal facility to dispose of its sludge on agricultural land rather than be required for landfilling. Sensitivity analyses to market interest rate, sludge production, sludge disposal fees and drag-out rates are explored.
Impacts of Heavy Metals on Higher Aquatic Plant, Diatom and Benthic Invertebrate Communities in the Niagara River Watershed near Welland, Ontario
Authors: Dickman M.D. , Yang J.R. , Brindle I.D. 
Published: March 2019

Abstract
Nickel, chromium, zinc and lead were 60 to 500 times more concentrated in the sediments downstream of the Atlas Specialty Steels Co. than they were in the sediments of the upper Welland River or in the nearby Lyon’s Creek. These metals reached concentrations of 4,900 mg kg−1 dry weight (ppm) of nickel versus 10 ppm upstream, 890 versus 5 ppm lead, 1,050 versus 30 ppm zinc and 5,120 verses 10 ppm chromium.
Changes in higher aquatic plant species composition and relative abundance downstream of the Atlas Specialty Steels Co. were plotted as a function of the downstream distance (800 m) from the point source discharge of the company. Four zones in the distribution patterns of aquatic plants were recognized. In the first zone (0–10 m from the point source) benthic invertebrates and aquatic plants were absent. In zone 2 (10–15 m from the point source) pollution tolerant benthic invertebrates such as sludge worms and blood worms as well as pollution tolerant long stemmed emergent macrophytes such as bulrushes and cattails first appeared. Further downstream (15–120 m from the point source), short stemmed macrophytes became abundant and benthic invertebrate diversity and density began to increase (zone 3). Only in zone 4 (120–800 m from the point source) did submersed macrophytes first appear and benthic invertebrates such as isopods, snails and leeches became established.
Sites where sediments displayed the highest levels of heavy metal contamination displayed low species richness and low benthic invertebrate densities. These same sites displayed the highest proportions of pollution tolerant chironomid genera such as Procladius cf. bellus and Phaenopsectra flavipes and the highest percentage of pollution tolerant diatoms such as Nitzschia hantzschia and N. palea.
Chironomid density was significantly lower below the point source (19 individuals m−2 versus 162 individuals m−2 upstream) as was species richness (11 versus 20 species, P &lt; 0.05). A similar pattern was evident for other benthic invertebrates as well as epipelic diatoms (15 vs. 34 species). In addition, the frequency of chironomid deformities was significantly higher at the downstream site than at the upstream “control” site (27% vs. 9%).
Indirect Polyphosphate Quantification in Activated Sludge
Authors: Comeau Yves , Hall Kenneth J. , Oldham William K. 
Published: March 2019

Abstract
An indirect biological method is presented to quantify the amount of polyphosphates in activated sludge obtained from wastewater treatment plants removing phosphate biologically. The method is based upon the property of such sludges to degrade polyphosphate reserves under anaerobic conditions as a result of acetate addition thereby releasing inorganic phosphate into solution. The addition of an excess of acetate ensures the consumption of any oxygen and nitrate, and the depletion of intracellular polyphosphates available for acetate storage. Thus, this new method offers a much easier approach than those previously available to quantify polyphosphate, one of the two storage polymers involved in the mechanism of biological phosphate removal.
Organic Contaminants in Canadian Coal Wastewaters and Associated Sediments
Authors: Atwater J.W. , Jasper S.E. , Parkinson P.D. , Mavinic D.S. 
Published: March 2019

Abstract
Wastewater and sediment samples were collected from 11 coal operations across Canada: 3 coal storage transfer terminals, 7 operating mines, 3 of which had on-site preparation plants, and 1 separate preparation plant. Samples were analyzed for specific organic and inorganic constituents. Only the results of the organic analyses are presented here. The wastewater samples were analyzed for 18 target compounds. Sediment samples were analyzed for these 18 target compounds plus a suite of organic priority pollutants. Twelve of the 18 target compounds were detected in wastewater, only 4 of which were found in excess of 10 μg/L in more than 10 percent of the samples. Sixteen compounds were found in the sediments at levels from less than 1 μg/g to a maximum of 27 μg/g. Limited experimentation indicated that coal sediments were unlikely to contribute organic contaminants to the water column but rather were more likely to absorb material out of the water column.
Review Paper: L’abattement des bactéries coliformes dans les étangs aérés facultatifs — 2. Variables abiotiques
Authors: Leduc Roland , Gehr Roland 
Published: March 2019

Abstract
Cet article passe en revue le rôle joué par les variables abiotiques dans le phénomène d’abattement des indicateurs de contamination fécale — en particulier les bactéries coliformes — dans les étangs aérés facultatifs. Les variables possédant les influences les plus marquantes sur la cinétique du phénomène d’abattement sont identifiées comme étant la température, l’irradiation solaire, le pH, l’oxygène dissous, les nutriments et la charge organique, et leurs rôles respectifs sont discutés. De plus, le temps de rétention, le nombre de bassins et le régime hydraulique sont identifies comme ayant une influence directe sur le rendement d’abattement des indicateurs fécaux dans les étangs. L’effet de l’usage de coagulants tels l’alun, la chaux et le chlorure ferrique et l’impact du pompage sont aussi discutés. Finalement, l’article suggère de nouvelles directions de recherche pour élaborer des critères plus adéquats pour la conception des étangs aérés.
Characterization of Groundwater Contaminants at Elmira, Ontario, by Thermal Desorption, Solvent Extraction GC-MS and HPLC
Authors: Lesage S. , Ritch J.K. , Treciokas E.J. 
Published: March 2019

Abstract
Contaminated groundwater samples were characterized using on-line thermal desorption GC-MS analysis. The results were compared with conventional solvent extraction method followed by GC-MS analysis. Thermal desorption gave similar results for most compounds and was found to be superior for the analysis of water-miscible compounds. HPLC with a diode-array detector was used to measure phenol in the presence of large quantities of aniline.
Removal of Organochlorines from Kraft Pulp Mill Effluent by an Aerated Lagoon
Authors: Tomar P. , Allen D.G. 
Published: March 2019

Abstract
The removal of chlorinated organic compounds from bleached kraft pulp mill effluent in an operating biological treatment system, consisting of an aerated lagoon and settling pond, was studied. The system performed extremely well for reduction of BOD. Preliminary results indicate that the overall removal of AOX was in the range of 15 to 47% across the entire system with the majority being removed in the aerated lagoon. Removal of low molecular weight (&lt;1000 dalton) AOX was greater at 43–50%. About one third (range 30–36%) of the TOC was removed and the ratio of AOX to TOC was relatively constant at about 0.124 (g AOX/g TOC) throughout the lagoon suggesting that the mechanisms of removal were the same for both. The amount of chlorine bound to the organic matter in the sludge and in the interstitial water was found to be relatively constant throughout the lagoon. Significantly less AOX was found in the interstitial water than in the overlying water.
Metal Concentration in Sediments (Bottom and Suspended) of St. Marys River, Ontario/Michigan
Authors: Mudroch A. 
Published: March 2019

Abstract
The geochemistry and distribution of Cu, Cr, Zn, Pb, Ni, Co, V and As were investigated in bottom and suspended sediment in the St. Marys River, Ontario/Michigan. Elevated concentrations, above background, of Fe, Mg, Ca, Mn, Pb, Zn, and As in suspended and bottom sediments were observed at the Canadian shore in the vicinity of the Algoma Steel slag dump. A further increase in the concentrations of these elements, particularly in the bottom sediment, existed near the Algoma Steel slip. In this area, the concentrations of Pb, Zn and As in bottom sediments (1865, 4600 and 92 µg/g, respectively) were many times greater than in the other sections of the river. However, the concentrations of Cr, Cu and Ni in suspended and bottom sediment increased at several locations along the St. Marys River indicating several different sources of these trace elements. The maximum concentrations of Cr, Cu and Ni in the bottom sediments were 1004, 102 and 53 µg/g, respectively. Generally, the concentrations of trace elements were considerably lower in the suspended sediments than in the bottom sediments. Concentration profiles of Cr, Zn and Pb and dating of sediment cores for Lake George in the lower St. Marys River system showed that metal contamination peaked between 1957 and 1965.
Freshwater Bacterial Aggregate Development: Effect of Dissolved Organic Matter
Authors: Rao S.S. , Droppo I.G. , Taylor C.M. , Burnison B.K. 
Published: March 2019

Abstract
Suspended sediment particles and bacteria because of their surface area and charge, may play a role in the binding of aquatic contaminants. Little is known, as to what degree each of these factors play in the formation of suspended aggregates. Flocculation of particles can alter their hydrodynamic properties in aquatic environments and therefore may have significant implications for contaminant transport. In this study, we examine the role dissolved organic carbon plays in the production of bacterial aggregates as a first step to gaining a better understanding of bacterial-particle interactions and suspended particulate formation.
Data indicated that an order of magnitude increase in bacterial population occurred due to the utilization of algal organic matter. This increase in bacterial density was closely accompanied by an increase in the size of the median bacterial aggregate from approximately 8 µm to 16 µm. This observation suggests that there is a greater potential for the sorption of aquatic contaminants by the aggregates.