bluuebunny/crossref_metadata_2025 huggingface dataset:
Utilization of Oxygen Models in Environmental Impact Analysis
Authors: Snodgrass W.J. , Holloran M.F.
Published: March 2019

A vertical one-dimensional temperature-oxygen model for reservoirs is used to estimate zones of stress on the aquatic environment of a series of reservoirs in Nova Scotia. Application to cold climates necessitated a few novel developments for the temperature model. The oxygen model whose sinks are water column decay and sediment oxygen demand (SOD) is calibrated using under ice measurements of oxygen stocks and laboratory and in situ measurements of a zero-order kinetic model for sediment oxygen demand. These extensive studies are complementary and indicate a winter SOD of 0.1 gm 02/m2/day and a higher summer value. High epilimnetic temperatures coupled with the predicted anoxic zones in lower waters cause a major stress upon fisheries potential. This model provides a tool for determining the effects of different reservoir management strategies upon water quality and for selecting among these strategies.
Sediment-Water Interchange of Copper and Nickel in Experimental Aquaria
Authors: Stokes P.M. , Szokalo A.M.
Published: March 2019

Lake and stream sediments often reflect recent additions of heavy metals before elevations of such elements are detectable in the overlying water. Concentrations of metals in sediments of lakes may be three to four orders of magnitude greater than in the water. While tests of water quality may, therefore, indicate no elevated metal levels in the soluble phase, a water body may still be heavily polluted, with organic and inorganic material in sediments acting as sites for precipitation and adsorption of the metals. The possibility of reentry of sedimented material into the water, due to physical, chemical or biological processes in natural situations, always exists.

Experimental work was carried out on nickel and copper in the sediments of Middle Lake (recently limed to pH 6.5, and fertilized) and of Clearwater Lake (untreated), Sudbury, Ontario, under a variety of physical and biological conditions in aquaria. Results showed that both copper and nickel increased in concentration in water overlying the sediments, eg. in “live” aerobic systems over 28 days total copper in water increased from 0.15 to 0.85 ppm, and total nickel from 0.3 to 3.0 ppm. The pH of the water, initially 6.5, dropped to below 4.0. In sterile anaerobic conditions, total copper decreased slightly, and total nickel remained constant, while pH in this condition initially dropped only slightly, and at 28 days was 6.0. The “live” anaerobic system was intermediate in all these respects.

“Free” copper at lower pH values (measured by differential pulse anodic stripping voltammetry) was predictably equal to total copper (measured by flame atomic absorption or by anodic stripping), but in the sterile anaerobic treatments where pH was 6.0, “free” copper was less than 50% of the total copper. Since ionic copper is believed to be the form toxic to biota, the lowered pH and increased ionic copper in water close to the sediments appears to have serious implications.
Chemosensory Bioassay of Toxicity of Lake Waters Contaminated with Heavy Metals from Mining Effluents
Authors: Thompson B.E. , Hara T.J.
Published: March 2019

The toxicity of natural lake waters contaminated with heavy metals from mining effluents was studied by perfusing water samples through the olfactory organs of Arctic char (Salvelinus alpinus) while recording the olfactory bulbar electrical responses to the standard stimulant, L-serine.

Of the five lake waters tested, only Ross Lake, the closest to the mining-smelting site, showed significant depressing effect on the olfactory response at levels as high as 100 times dilution. Chemical analysis of lake waters revealed that Ross Lake had the highest concentrations of heavy metals; 43 μg/1 Cd, 98 μg/1 Cu, <15 μg/1 Ni and 7720 μg/1 Zn. Single component experiments showed that Cu and Cd are probably responsible for most of the depressive effect.

The depressive effect of natural lake water was less than that of an artificial lake water composed of heavy metals based on the natural lake concentrations. Possible involvement of complex formation of heavy metals in the reduction of their toxicity is discussed.
The Effect of Metallic and Ionic Species on the Performance of a Biological Effluent Treatment System
Authors: Volesky B. , Samak Q. , Waller P.
Published: March 2019

Review of the available results appearing in the recent literature is presented focusing particularly upon the effects of metallic ions such as Cr, Cu, Zn, Cd, Hg, V, Zn, Ni and Co. Some original data involving the effects of Na are presented and discussed. Development of parameters used in evaluating the influence of toxic or inhibitory species on the mixed microbial population of an activated sludge system is of crucial importance and different techniques employed such as BOD-COD-TOC-removal rates, Oxygen Uptake Rate, and others are discussed, showing relative inadequacy of currently applied assays.

From the data available, certain trends can be discerned. There is a definite threshold concentration for each metallic ion, depending on the organic load of the feed. In the order of increasing toxicity to activated sludge systems reflected in lower BOD removals the following metals have been listed as inhibiting factors at concentrations starting from 1 ppm applied on a continuous basis: hexavalent chromium, cobalt, zinc, cadmium, trivalent chromium, copper and nickel.

Metals in combination have not been reported to exhibit any significantly different effects as compared to those observed with individually introduced metallic ions. Tolerance of some activated sludge systems to shock loadings by various inorganic ions and metals is reviewed. The conclusions are of particular importance for estimating the performance of biox systems handling industrial effluents which are likely to contain toxic components of inorganic or metallic nature.
Detergent Phosphorus Legislation: A Technical Appraisal of its Effectiveness
Authors: Budd R.A. , Jones P.H.
Published: March 2019

This literature review provides a technological evaluation of government legislation on phosphate contents in commercially available detergents to decrease P inputs and thereby reduce the rate of eutrophi-cation to receiving waters.

The predicted 50-60% reductions of phosphorus in raw sewage were achieved in the cases studied. This was attributable to regulation of detergent phosphorus. This study reports six years after such legislation was enacted in Canada, a statistical analysis of historical data on plants operated by the Ontario Ministry of the Environment. It illustrated that with 95% confidence the 1976 influent phosphorus concentration has decreased from 33 to 55% of the 1970 influent values.

Decreases in energy consumed and sludge volume indicated that detergent reformulation legislation is not only a very effective interim measure for reducing phosphorus loadings (results being realized immediately) , but provides a cost-effective complementary system to existing phosphorus removal programmes.

The reduction in phosphorus loading to receiving waters is an established fact. However, the impact of decreased P loadings, whether through legal measures or chemical removal, is difficult to quantify because of the many complex variables affecting water quality and algal biomass in aquatic ecosystems.
Catalytic Wet Oxidation of Phenolic Solutions
Authors: Doreau G. , Chornet E.
Published: March 2019

In the present study- the activity and selectivity of three oxidation catalysts were tested in order to reduce the severity of wet oxidation of phenolic solutions. A one litre batch reactor was used and intermittent sampling and analysis of the gaseous and liquid phases was carried out on a routine basis.

The first experiments showed that main intermediates formed during the oxidation reactions were polyphenols, acetic acid and formic acid. Temperatures up to 150°C and oxygen pressures resulting in up to five times the stoichiometric amount of oxygen needed for the total oxidation of phenols were used for the studies.

The work done to date shows Pt/C catalyst superior to CuO/Cr2O3 and Ag/Al2O3 as far as activity and selectivity are concerned. Only the Pt/C catalyst yields a complete oxidation without significant formation of acetic and formic acids.
Effects of benzene, a water soluble component of crude oils, on membrane integrity and ionic content of the green alga Ankistrodesmus falcatus var. mirabilis
Authors: Kauss P. B. , Hutchinson T. C.
Published: March 2019

Experiments were devised to investigate the effects of the aromatic hydrocarbon benzene on the membrane integrity of the green freshwater alga Ankistrodesmus falcatus var. mirabilis. The ability of cells to retain ions (e.g. calcium, chlorine, copper, magnesium, manganese and potassium) when exposed to benzene was used as a measure of cell membrane disruption. Cells were exposed to various dosages of benzene in the light and the dark. Samples removed at pre-determined time intervals were analyzed for the above elements using neutron activation analysis. It was found that, (at dosages greater than ~24 umoles benzene per μl−1 cell volume), the rate of loss of potassium and manganese was proportional to both the benzene dosage and the time of exposure, but not affected by illumination. However, although loss of potassium and manganese from cells was complete after 24h exposure to the highest benzene dosage used (48 μmoles. μl−1) only a fraction of calcium, chlorine, copper and magnesium had been lost. This suggests a difference in the degree that these elements are bound or free in the cells, and that loss of potassium and manganese from cells is a sensitive indicator of cell membrane damage.
Mixing Efficiencies in Full-Scale Anaerobic Digesters by Tracer Methods
Authors: Monteith H.D. , Stephenson J.P.
Published: March 2019

Tracer analyses of the full-scale anaerobic digestion processes as two water pollution control plants revealed that nonideal mixing conditions existed. In both systems, 75% of the total volume of the gas-mixed primary digesters was inactive, significantly reducing the effective hydraulic retention time in one system to approximately 5 days compared to the theoretical mean of 22 days. In the other primary digester, short-circuiting around the actively mixed zone accounted for 61% of the input flow. The fundamental objectives of digestion cannot be realized under these operating conditions. The results prove that greater attention must be given to reactor mixing in the design and operation of anaerobic digesters.
Modeling Nitrate Transport in a Small Upland Stream
Authors: Stammers W.N. , Robinson J.B. , Whiteley H.R. , Kaushik N. K. , Sain P.
Published: March 2019

Swifts Brook, a small headwater stream within the Grand River Watershed in Southern Ontario, originates, during baseflow periods, in a spring with a high nitrate concentration. The spring, which is the principle source of summer streamflow for the brook, has peak flow rates of up to 5.5 l sec 1 in March and April and minimum flowrates as low as 2.8 l sec in August or September. The nitrate concentration in the spring is highest during periods of highest flowrate and lowest in October or November. The mean annual concentrations of NO3 ~*-N in the spring outflow, weighted by flowrate, were 4.3 mg SL * in 1975 and 4.1 mg l in 1976.

During dry summer conditions a two km reach of the main channel, beginning at the spring, receives no surface flow contributions from ephemeral tributaries. Stream processes in this portion of the stream channel were studied in detail (Robinson et al. 1977). The location of the spring and study reaches are shown in Fig. 1. For this reach, the stream water surface width varied from 0.7 to 3.8 meters and the water depth and average velocity vary from 0.08 to 0.23 meters and 0.004 to 0.05 m sec respectively.
Fecal Sterols: Their Distribution in Water and Resultant Significance
Authors: Switzer-Howse K.D. , Dutka B.J.
Published: March 2019

Samples of raw sewage and clarifier effluent were collected to study the effect of (!) centrifugation, (2) sonication, and (3) sonica-tion followed by centrifugation, on the distribution of fecal sterols within a sample, as compared to untreated samples. Samples were analyzed by GLC immediately after treatment. The procedure was repeated on samples which were stored for 1 week at 4°C. Bottles which had been used to store the samples were analyzed to determine whether adherence of fecal sterols to the glass storage container occurred.

Results Indicated that centrifugation of the raw sewage sample produced an average ten-fold concentration of fecal sterols in the sediment pellet as compared to the supernatant, while similar treatment of the clarifier effluent produced an average four-fold increase in fecal sterols in the sediment pellet. Sonication of samples prior to centrifuging did not affect these results significantly. Data obtained from the stored samples showed a similar distribution of fecal sterols upon centrifuging of sample prior to analysis. Analysis of the glass storage bottles (for fecal sterols) showed that the adherence of fecal sterols was not a problem.
Field Observations of Tracer Dispersion Under Natural Flow Conditions in an Unconfined Sandy Aquifer
Authors: Sudicky E.A. , Cherry J.A.
Published: March 2019

ABSTRACT An exceptionally detailed field determination of the solute transport parameters was performed in an unconfined sandy aquifer near an abandoned landfill at the Canadian Forces Base at Borden, Ontario. The test site is located above the contaminant plume originating from the landfill. The aquifer consists of slightly stratified sands with minor laminations. A chloride salt solution was injected into a two m3 volume of aquifer about one meter below the water-table and then migration of the tracer occurred under the natural hydraulic gradient. The migration of the chloride pulse was monitored in detail using a three-dimensional array of bundle-type multilevel samplers. Hydraulic head measurements in the zone of transport were obtained from a network of miniature piezometers. The test results demonstrated the influence of zones of local aquifer heterogeneity on solute migration rates and the ability of a porous medium to disperse solutes in these zones. Different rates of groundwater flow between a fast and slow transport zone caused the pulse to split into two halves. Each half was found to be Gaussian in shape in accord with the classical theory of solute transport. The measured chloride distributions closely fit an analytical solution of the advection-dispersion equation. Dispersivity values for chloride obtained from the analytical solution increased with mean travel distance in the groundwater flow domain, which suggests that calibration of a deterministic model at one spatial scale may lead to erroneous predictions when applied to a different scale. From this it is concluded that, if deterministic models are to yield useful predictions of contaminant migration, it will be necessary to establish scaling functions from studies of the variability of transport parameters in a wide range of hydrogeological settings.
Comparison of Methods and Concepts Used in Assessing the Extent of Water Pollution in a Canadian Shield Lake
Authors: Moore J.W. , Sutherland D.J. , Beaubien V.A.
Published: March 2019

The relative merits of several different methods and concepts used in the assessment of water pollution were determined during 1977 in Giauque Lake, situated in the Northwest Territories. The lake had become polluted through the operations of a gold mine, which discharged mercury-1aden tailings and other waste material directly into the water. The concentration of mercury in the sediments decreased as the distance from the mine increased. Concentrations of over 5000 µg/kg (dry weight) were found in the immediate vicinity of the tailings fan, whereas, at distances of 1.0 and 1.3 km from the fan, the level of mercury averaged 1000 and 100 µg/kg, respectively. Because an extensive series of bottom samples were collected, it was possible to designate a well-defined zone of chemical contamination in the sediments. There was a strong, negative correlation between the density of benthic invertebrates in the sediments and the level of mercury contamination. Consequently, a zone of influence paralleling that outlined for the chemical analysis could again be delineated. However, the diversity index and species composition of the benthic communities gave no indication of environmental impact. Since the waters of Giauque Lake contained extremely low levels of heavy metals, the diversity, species composition and density of zooplankton communities were not useful in assessing the zone of influence. It is concluded that direct determinations of the concentrations of heavy metals in the sediments and the density of benthic organisms were the only effective means of monitoring the extent of pollution in the lake. Other traditional methods, such as diversity indices and the species composition of the fauna and the measurements of water quality gave little if any indication of contamination.
Improvement of Clarifier Performance
Authors: Cordoba-Molina J.F. , Hudgins R.R. , Silveston P.L.
Published: March 2019

Clarifier operation is a fluid flow problem which, up to now, has been viewed in terms of homogeneous fluid concepts. However, flow in clarifiers is stratified since its density decreases with height. This stratification gives rise to phenomena that do not exist in homogeneous fluids. These appear to cause mixing which decreases removal efficiency. In this paper, we show how by using downstream contractions in the flow, it is possible to virtually double the capacity and increase the removal efficiency of clarifiers.
The Impact of Industrial Shock Loading on Selected Biocoenoses in the Lower Welland River, Ontario
Authors: Dickman M. , Smol J. , Steele P.
Published: March 2019

A baseline for biological and chemical water quality conditions was established for a section of the Welland River which daily receives large quantities of nitrogenous and carbonaceous inorganic compounds from Cyanamid of Canada Limited.

Specific conductivity transects across the river at various locations indicated that the effluents discharged clung to the north shore of the River. In addition, simultaneous continuous conductivity measurements from above and below the plant were made during five one-week long periods and the results temperature corrected. At the upstream site conductivity never exceeded 400 limhos/cm while below the plant it averaged 950 umhos/cm with sporadic peaks exceeding 1 0,000 umhos/cm.

Epiphytic diatoms scraped from typha stalks growing in the water at sites above the plant were dominated by Nitzschia dissipata, while the pollution tolerant diatom, Nitzschia palea, dominated at the majority of the downstream sites. In addition, blue green algae replaced filamentous green algae below the plant.

Higher aquatic plants reflected a very distinctive zonation pattern. No higher aquatics were found growing in the water in the impact zones immediately below the effluent outfalls. The first macrophytes to appear downstream of these sites were cattails, while further downstream the arrowheads (sagittaria) and later the submersed macrophytes, such as Elodea and Myriophyllum appeared.

No resident fish population occurred along the north shore downstream of the plant. Shiners and other small transient fish species which were observed entering the effluent plume near Thompson's Creek during periods of shock loading went "belly-up" within one minute indicating the extreme toxicity of these waters.
Variation in Sludge Settleability with Temperature
Authors: Henry J.G. , Salenieks E.E.
Published: March 2019

This study examined the effect of temperature on the settleabi1ity of activated sludge at various organic loading rates. Five completely mixed, bench-scale, activated sludge plants, operating under similar conditions at 5, 10 and 19°C, were continuously fed diluted, settled sewage supplemented with carbohydrate (sucrose). Hydraulic loading rates, MLSS and pH were maintained at constant levels during the experiments to eliminate these factors are variables. Dissolved oxygen was kept in excess of 3 mg/1 so that it would not be a limiting factor. Sludge Volume Indices (SVI ) and zone settling velocities were used to indicate changes in sludge settleability.

Microscopic examination of the activated sludge indicated significant differences in the morphological features of filamentous microorganisms present at the two temperature extremes. At 19°C, the predominant forms were characterized by long curving trichomes, occasionally falsely branching, containing short cylindrical cells. At 5 °C, much smaller straight filaments, composed of long, narrow, rod-shaped cells appeared to be the principal microorganisms responsible for bulking. Various other filamentous forms were always present at each of the temperatures studied.

Stirred sludge settling tests of moderately bulking sludges generally exhibited much higher settling velocities and lower SVI's than unstirred bulking samples. However, extremely filamentous bulking sludge exhibited comparable stirred and unstirred settling velocity and SVI values. The standard SVI test was found to be an inadequate indicator of the extent of bulking when trying to correlate the SVI failures from bench-scale performance with the results from continuous units. Lower temperature had no appreciable effect on COD removal efficiency as long as bulking did not cause a loss of solids in the effluent. However, results suggested that less than half the organic load could be accepted at 5°C, that could be handled at 19°C, before filamentous bulking occurred. A plot of loading versus temperature for various SVI's provided a visual indication of the safe loading limit below which bulking was unlikely to occur. The study clearly demonstrated that temperature can have a significant effect on sludge settleability.
Volatilization Rates of Organic Contaminants from Rivers
Authors: Mackay D. , Yuen T.K.
Published: March 2019

A review is first presented of the present state of knowledge concerning the volatilization of organic contaminants from rivers. A series resistance model is derived which enables the volatilization rate to be calculated from a knowledge of river bulk resistance and the air and water near-interface resistances. The importance of Henry's Constant in determining the prevailing volatilization regime is demonstrated. It is shown that the considerable body of information on reaeration rates and particularly the more recent development of the Rathbun hydrocarbon-dye tracer technique provide valuable data on liquid phase resistance. The flux equation is coupled to the river mass flow balance to give an expression for contaminant concentration decay as a function of time or distance of flow. The feasibility of artificially aerating a stream to enhance volatilization is discussed and feasibility shown to be restricted to compounds of high Henry's Constant, except possibly in the presence of ice when volatilization rates may be reduced to undesirably low levels. The rate of sorption in reducing volatilization rate is discussed and quantified. Comparison between the few available literature data and the derived equations shows satisfactory agreement.
Cost Optimization of Wastewater Treatment Plant Design Preliminary Design Including Sludge Disposal
Authors: Narbaitz R.M. , Adams B.J.
Published: March 2019

A computer based design methodology was developed to facilitate and improve the preliminary design of wastewater treatment plants. It aids design by choosing the least cost treatment system (including sludge treatment and disposal) which meets all the constraints of the particular application. This methodology not only chooses the best alternative treatment system among numerous alternatives but also finds the optimal values of the independent design variables of the processes forming the optimal treatment system. In addition, it has two advantages over currently available design methodologies in that it optimizes wastewater treatment design with respect to the removal of more than one water quality parameter and it considers that sludges produced by different processes have different qualities. This methodology is based on a nonlinear programming method termed optimization by random search and systematic reduction of the size of search region. The design procedure was used to analyze a particular example problem.
The Photochemical Treatment of Wastewater by Ultraviolet Irradiation of Semiconductors
Authors: Carey John H. , Oliver Barry G.
Published: March 2019

The primary photoefficiency of ten semiconductors to produce reactive oxidising species under ultraviolet (UV) illumination has been evaluated. TiO2 in the anatase phase was shown to be at least an order of magnitude more efficient than the other semiconductors so was chosen for further experimentation. While the anatase-UV treatment was shown not to be feasible for secondary effluent disinfection, the process did lead to substantial reduction in the toxicity to algae of PCB containing wastewater. Also, the process reduced the total organic chlorine content of a pulp and paper plant's chlorinated bleach-plant effluent and left lignin model compounds more amenable to biological degradation. In addition, the process destroyed cyanide in synthetic solutions and in gold and base metal mine effluents. Based on studies of model compounds, the reaction mechanisms for the process are discussed. Also, recommendations are made as to future research requirements for optimization of the process and for study of its economic viability.
Etude limnologique du bassin versant du Lac Saint-Jean (Quebec, Canada): considerations sur un systeme physique heterogene
Authors: Couture P. , Visser S.A.
Published: March 2019

La variabilité spatiale des eaux du lac Saint-Jean est suivie en situant, de façon relative, les valeurs mesurées à chacune des 50 stations réparties sur le lac par rapport à des seuils critiques définis pour les paramètres suivants: température, couleur apparente, carbone organique total, azote Kjeldahl, phosphore total, coliforms totaux, chlorophylle-a active et potentiel autotrophe. Deux régions sont ainsi identifiées; un ensemble de symptômes (impliquant la couleur, les concentrations en phosphore, en azote Kjeldahl, et les valeurs des potentiels autotrophes) observés dans ces régions met en évidence des conditions non conformes à celles rencontrées en milieu oligotrophe.
Role of Psychrotrophic Bacteria in the Degradation of Waste Activated Sludge
Authors: Henry J.G. , Prasad D.
Published: March 2019

A series of batch and semi-continuous laboratory scale aerobic reactors was evaluated, with emphasis on the microbiological aspects. Batch treatment of waste activated sludge (COD 10,000 mg/l) was carried out over a period of eight weeks in three separate reactors at 5, 10 and 20°C. A semi-continuous unit operating at 5°C was investigated at a loading rate of 0.64 kg VSS/m3/day. Analyses performed included pH, O2 uptake rate, total solids, suspended solids, volatile suspended solids and COD determinations. The microbiological tests included total plate counts (20°C) and psychrotrophic counts (l°C).

Results indicated that long (impractical) detention times were required to aerobically treat waste activated sludge at low temperatures. At temperatures supposedly favourable to psychrotrophic growth, it was found that the proportion of psychrotrophic bacteria could not develop to a significant level and remained at less that 1% of the total viable bacterial population, regardless of the mode of operation or the detention time. This is in contrast to the finding that approximately 54% of the viable bacteria in the aeration tank of a large conventional activated sludge plant, operating at a mixed liquor temperature of 13°C, were psychrotrophic. It is apparent that psychrotrophic bacteria played an insignificant role in the degradation of waste activated sludge at low temperatures, (5 and 10°C) and that biological oxidation was performed primarily be mesophilic bacteria. The study indicated that under the experimental conditions employed, the amount of available substrate present was one of the major regulating factors in the development or selection of psychrotrophic bacteria.
UV Disinfection of Tertiary and Secondary Effluents
Authors: Ho K.W.A. , Bohm P.
Published: March 2019

The practicality of disinfecting sewage effluents with ultraviolet light irradiation CUV) was investigated with a pilot scale proprietary unit. Field study results demonstrated that UV irradiation could consistently achieve a bacteriological quality of 2,500 total coliform counts/100 ml in tertiary and high quality secondary effluents. This bacteriological quality could be maintained in effluents simulating minor plant upset conditions.
An Experimental Investigation into the Induced Air Floatation of Fine Oil in Water Emulsions
Authors: Behie Leo A. , Van Ham Cornelius J.M. , Berk Dimitrios
Published: March 2019

The induced air flotation (IAF) of a highly stabilized oil in water (o/w) emulsion has been studied experimentally in a batch column 10 cm in diameter and 150 cm in height. The main variables investigated were initial oil concentration (50 - 600 mg/L), oil droplet size distribution of feed (1.0 - 30 um), type of surfactant, gas superficial velocity, volume of liquid feed, and type of air distributor. Results were successfully analyzed in terms of a first order kinetic rate model which yielded a removal rate constant (K1) that varied from 2.0 to 60.0 h-1. Corresponding total organic carbon (TOC) removal efficiencies went from 20 to 99.9 percent illustrating the wide performance range for the flotation cell. In addition, an important contribution of this work was the development and recommendation of a standard method to create and quantitatively characterize test emulsions for use in experimental flotation equipment. Emulsion stabilities were determined experimentally from a static test and quantified in terms of a stability rate constant. This constant was less than 0.001 h-1 for highly stable emulsions and greater than 0.20 h-1 for unstable emulsions. For the values of K1 between these two extremes, emulsions were only moderately stable.
Nitrogen Mineralization in Soils Treated with Sewage Sludge and Sawdust
Authors: Jones P.H. , Dalgity C
Published: March 2019

Municipal sewage sludges are frequently disposed of on agricultural land. The oxidation of nitrogen provides a source of NO3-, which may leach from the soil or enter runoff water causing a number of pollution problems in groundwater, lakes and streams. The addition of sawdust to the sludge was studied as an inhibitor of nitrification in this process. Various mixtures of sewage sludge and of sawdust were studied under laboratory conditions to determine the effect on nitrogen mineralization (ammonification and nitrification). The addition of an organic nitrogen source accelerated the rate of nitrification. The maximum observed rates were as follows: untreated soil 2.5 pg/gm3-N/day and sludge treated soil 3.9 ug/gm3-N/day. The addition of sawdust inhibited nitrogen mineralization. The maximum rate of nitrification for the 1:3 sludge/sawdust mixture in the laboratory was 2.4 ug/gm3-/nitrogen per day and the 1:14 sludge/sawdust mixture yielded 1.6 ug/gm3-/nitrogen per day. The tannins in the sawdust appeared to be the inhibitory factor in these experiments. The results of these experiments suggest that co-disposal of sewage sludge and sawdust on land will reduce the rate of production of nitrate with the resulting reduction of pollution of ground and surface waters.
Treatment of a Municipal Leachate Under Multi-Variable Conditions
Authors: Wong P.T. , Mavinic D.S.
Published: March 2019

The treatability of a municipal leachate (BOD5 = 8090 mg/L) was investigated, by aerobic biostabilization, at a nutrient loading of BOD5:N:P of 100:3.2:1.1. The first stage effluents were subsequently polished by lime-magnesium coagulation. The ranges of ambient air temperature and sludge age studied were 5° to 25°C and 5 to 20 days, respectively.

In the biostabilization phase, a BOD5:N:P loading of 100:3.2:1.1 was found to be “adequate” for treatment. Organic and metal removals in the first stage units were excellent. Under all conditions investigated, except for the two units close to washout conditions (5-day sludge age units at 5° and 10°C), BOD5 and COD removals of at least 99.4 and 96.4 percent, respectively, were achieved. Similarly, removal rates for most of the metals monitored were greater than 90 percent. In general, the removal of residual contaminants was not enhanced significantly by the addition of magnesium in the lime-magnesium polishing step.
Acute Toxicity, Kinetics and Metabolism of Aminocarb in the Brown Bullhead (Ictalurus nebulosus)
Authors: Richardson G. Mark , Qadri S.U.
Published: March 2019

Aminocarb was shown to have low acute toxicity to brown bullhead (Ictalurus nebulosus), when exposed via water, with rapid clearance and only low persistence of pesticide residues. Clearance of aminocarb residues was effectively described by a 2-compartment model and fractional clearance rates did not differ significantly over the range of exposure concentrations tested. It was calculated that fingerling brown bullhead would require about 25 days to eliminate residues of aminocarb from their tissues to less than 0.01 ug/g fish following an environmental exposure to 24 ppb for one day's duration. Residues present beyond the first day of the post-exposure period likely represent non-toxic metabolites and not aminocarb or toxic metabolites such as 4-methylamino-3-methylphenyl N-methylcarbamate.
Formation and Removal of Volatile Organics in Surface Water Treatment
Authors: Huck P.M. , Andrews R. , Gammie L.
Published: March 2019

A four month study was carried out at the Buffalo Pound Water Treatment Plant near Regina, Saskatchewan to examine the formation and removal of volatile organic compounds. Nine volatile organics were found to be consistently formed or added to the water during full scale conventional treatment. Only the chlorine-containing trihalomethanes were present at levels greater than 1 ug/L. Removal of these compounds was investigated in pilot scale granular activated carbon post contactors; the study examined both fresh carbon and carbon which had been used in a previous four month investigation. All compounds were removed to some degree on the carbon. The location of removal within the columns varied with the different compounds and the results suggested formation of some compounds within the columns. Post chlorination of column effluent resulted in at most a modest increase in the concentrations of the organic compounds.
Density Wave Measurements in a Rectangular Clarifier
Authors: Watson Mark K. , Hudgins R.R. , Silveston P.L.
Published: March 2019

Internal wave motion was studied in a laboratory rectangular, primary clarifier. A photo-extinction device was used as a turbidimeter to measure concentration fluctuations in a small volume within the clarifier as a function of time. The signal from this device was fed to a HP21MX minicomputer and the power spectrum plotted from data records lasting approximately 30 min. Results show large changes of wave amplitude as frequency increases. Two distinct regions occur: one with high amplitudes at frequencies below 0.03 Hz, the second with very small amplitudes appears for frequencies greater than 0.1 Hz. The former is associated with internal waves, the latter with flow-generated turbulence. Depth, velocity in the clarifier and inlet suspended solids influence wave amplitudes and the spectra. A variation with position or orientation of the probe was not detected. Contradictory results were found for the influence of flow contraction baffles on internal wave amplitude.
Bacterial Leaching of Heavy Metals From Anaerobically Digested Sewage Sludge
Authors: Wong L. , Henry J.G.
Published: March 2019

Spreading of sewage sludges on agricultural land is an attractive sludge management option because it combines beneficial reuse and disposal at the same time. However, it is important to reduce the metal content in the sludge in order to minimize the health hazard associated with metal uptake by plants and its subsequent accumulation in the food chain. Treatment of sludge with acid for metal removal is not practical because a large amount of acid is required. Typically 0.5 to 0.8 g of H2SO4/g dry weight of sludge will be required to achieve over 70% removal of cadmium (Cd), zinc (Zn) and nickel (Ni). Lead (Pb) and copper (Cu) are not significantly removed. A biological process called bacterial leaching, which has been used commercially for extracting copper and uranium from low grade ores, was reviewed and its potential for removing heavy metals from anaerobically digested sewage sludge was investigated. Leaching experiments were conducted and the results showed that about 80 to 90% removal of cadmium, zinc and nickel, and 60 to 70% removal of copper were possible. The acid requirement was significantly reduced because only 0.15 g of H2SO4/g dry weight of sludge was needed.
Particle Size Effects on Concentration of Metals in Lake Erie Bottom Sediments
Authors: Mudroch Alena
Published: March 2019

Surface sediment samples obtained at the offshore and nearshore area of Lake Erie were separated into eight different size fractions ranging from <2 µm to 250 µm. The concentration of major elements (Si, Al, Ca, Mg, K, Na, Fe, Mn and P), metals (Zn, Cu, Cr, Ni, V, Co and Pb) and organic matter was determined together with the mineralogical composition and morphology of the particles in each size fraction. The distribution of the metals in the offshore sediment was bimodal with the majority of the metals divided between the 63 to 250 um size fraction which also contained the highest concentration of organic matter (about 20%) and the <4 µm fraction containing up to 60% of clay minerals. However, the metals in the nearshore sediment were associated mainly with the clay minerals.
Distribution and Pathways of Some Chlorinated Benzenes in the Niagara River and Lake Ontario
Authors: Oliver Barry G.
Published: March 2019

Three major processes have been shown to be responsible for losses of chlorobenzenes, CB's, from water of the Niagara River and Lake Ontario -volatilization, sedimentation and discharge via the St. Lawrence River. The major losses (>80%) for all the CB's including hexachlorobenzene, HCB, were by volatilization. As would be predicted from chemical and physical properties, among all the CB's, HCB has the lowest tendency to volatilize and the highest tendency to become associated with suspended sediments. A compartmental analysis of CB's in Lake Ontario revealed that the bulk of the CB's in the lake is in the bottom sediments. The bottom sediments in the lake have been shown to be prone to resuspension and become redistributed to all the major sedimentation basins in the lake. At least a portion of CB's associated with bottom sediments appears to be available to lake biota.
Nitrogen Removal from Anaerobically-Treated Leachate
Authors: Prasad D. , Henry J.G. , Elefsiniotis P.
Published: March 2019

Laboratory studies were conducted to demonstrate the effectiveness of diffused aeration for the removal of ammonia from the effluent of an anaerobic filter treating leachate. The effects of pH, temperature and air flow on the process were studied. The coefficient of desorption of ammonia, KD for the anaerobic filter effluent (TKN 75 mg/L with NH3-N 88%) was determined at pH values of 9, 10 and 11, temperatures of 10, 15, 20, 30 and 35°C, and air flow rates of 50, 120, and 190 cm3/sec/L.

Results indicated that nitrogen removal from the effluent of anaerobic filters by ammonia desorption was feasible. Removals exceeding 90% were obtained with 8 hours aeration at pH of 10, a temperature of 20°C, and an air flow rate of 190 cm3/sec/L. Ammonia desorption coefficients, KD, determined at other temperatures and air flow rates can be used to predict ammonia removals under a wide range of operating conditions.
Evidence for Non-equilibrium Adsorption of 90Sr from Ground Water
Authors: Lyon K.E. , Patterson R.J.
Published: March 2019

In June 1960, twenty-five 14 cm diameter hemispheres of vitrified nuclear waste (glass blocks) were buried below the water table in the lower Perch Lake Basin, Chalk River Nuclear Laboratories, Chalk River, Ontario, Canada. Almost all leaching of the glass blocks occurred during the first several months of emplacement, and consequently the burial experiment approximated a single-injection source of 137Cs and 90Sr. After about 18 years, most of the 90Sr that was released had been transported away from the blocks.

Three piezometers were installed and five cores of sediment were collected at the glass block site in 1978. Mineralogically pure segregates of sand grains were prepared by hand and characterized using binocular, petrographic, and scanning electron microscopy, x-ray diffraction, and energy dispersive x-ray spectroscopy. A technique was developed to measure very low levels of 90Sr in small (10-100 mg) samples.

Results indicate that sand sized grains of biotite-vermiculite, biotite, and hematite-bearing feldspar (largely microcline) are able to retain low levels of 90Sr over a period of 18 years. The complete series of mineral segregates can be ranked on a weight basis according to the amount of retained 90Sr as follows:

biotite-vermiculite≥

biotite and translucent pink and opaque orange feldspar>

all other mineral segregates (quartz, white feldspar, hornblende and muscovite).

Ground-water quality data show that none of the retention 1s the result of the precipitation of strontium minerals. Results for the mineral segregates indicate, however, that oxides play a significant role in the retention of 90Sr. Calculations incorporating ground-water 90Sr concentration data and experimental Kdsr values indicate that a spectrum of adsorption sites, ranging from readily reversible to very slowly reversible, exist on the sediment for 90Sr.
The Port Grandby Radioactive Waste Management Site
Authors: Platford R.F. , Bobba A.G. , Joshi S.R.
Published: March 2019

About 2.5 x 105 m3 of ground water flows annually from the Port Granby site into Lake Ontario. This water carries with it about 2.5 x 10 Bq of Ra 226 and 25 kg of uranium into the lake. Both of these elements are diluted to within acceptable levels beyond a one metre distance from the shore.
Natural Radionuclides in the St. Lawrence River
Authors: Grondin D. , Lupien M.D.
Published: March 2019

The alum floc sampling method has proven to be a rapid and efficient means for studying radioactivity in freshwater, allowing the preconcentration of not only soluble nuclides but also those attached to the suspended material in rivers. This paper contains an assessment of the distribution of naturally occurring radionuclides between the liquid and solid phases present in the St. Lawrence River. It also describes the distribution of these natural radionuclides on the various fractions of the suspended material. A radioactivity profile observed at St. Foy, Québec, reveals the contribution of each tributary to the solid and liquid fluxes of the St. Lawrence River.
Spéciation de radionucléides dans les suspensoides du Fleuve St. Laurent
Authors: Turcotte J. , Grondin D. , Roy J.-C. , Côté J.-E.
Published: March 2019

About forty radionuclides, some naturally occurring, others artificially produced, have been detected in the St. Lawrence River at the heights of Québec City. Speciation studies of the radionuclides present in the suspended matter transported by the river were carried out from samples collected with a swimming pool type sand filter. Speciation was done with the reagents commonly used for similar studies for trace metals in sediments. Four fractions have been characterized; one associated with the carbonates, another with the iron and manganese oxides, the organics and the residue. The distribution of the radionuclides on these different fractions gives useful information on the type of interaction between the radioactive species and the solid phase. For instance, 7Be, 106Ru, 144Ce and 210Pb are weakly retained on the solid phase whereas naturally occurring radionuclides like 228Th, 238U, 226Ra, 40K and 137Cs are strongly retained on it. Airborne 210Pb following the decay of 222Ra in the air is the most likely source for this nuclide since most of it is not supported by 226Ra. In many respects, 210Pb seems to behave like the airborne 7Be.
Anaerobic Treatment of High Strength Acidic Organic Wastewaters Utilizing the Upflow Sludge Blanket Treatment Process
Authors: Trudell M. , van den Berg L. , Kosaric N.
Published: March 2019

A laboratory bench-scale study was undertaken in order to investigate the anaerobic biological treatment of high-strength acidic organic wastewaters utilizing the Upflow Sludge Blanket (USB) treatment process. A synthetic wastewater was utilized having a pH of 4.2 and consisting primarily of acetic and propionic acids.

While operating at substrate loading rates of 1.1 and 2.4 kg COD/kg VSS/d (i.e., 10 and 30 kg COD/m3/d, respectively), the USB treatment process removed in excess of 90 per cent of the total COD present in the raw wastewater, for waste strengths of 2 to 32g COD/L and hydraulic retention times varying between 3.2 and 76.8 hours. The process demonstrated the ability to polish the effluent waste stream to effluent COD concentrations of less than 300 mg/L. The process was able to tolerate hydraulic and waste strength shockloads. No observable deterioration in pH or effluent quality was identified following sudden increases in wastewater concentration (e.g., 4 to 32g COD/L) or decreases in hydraulic retention time (e.g., 25.6 to 3.2 hours). The use of effluent recirculation did not influence treatment efficiency but was necessary in order to partially neutralize the influent low pH wastewater.

The results of this research also demonstrate the feasibility of utilizing the USB reactor as the methane forming reactor in a two-stage anaerobic wastewater treatment system. Recommendations are provided concerning the design of such a system.
The Application of Sequencing Batch Treatment to an Industrial Wastewater
Authors: Décréon A. , Thérien N. , Jones J.P.
Published: March 2019

A laboratory-scale study has demonstrated the technical feasibility of using a sequencing batch reactor to treat the wastewater from the manufacture of shampoo and other personal care products. The results demonstrate that good treatment (90% removal efficiency for organic substrate as measured by TOD) is possible at an organic loading below 0.70 kg TOD/kgVSS/day. Higher ratios provide some treatment but there may some risk of washing out the biomass when the organic loading exceeds 1.4 kg TOD/kg VSS/day. The effluent produced was suitable for discharge to a municipal sewage system or to a polishing pond but not for direct discharge to receiving waters.

The treatment was totally adequate when nutrients were kept in the ratio B0D5/N/P of 100/5/1. Results were obtained for a ratio of 100/2.5/0.5 and the system did not adequately remove organic material. The response to an inadequate supply of nutrients was very rapid and the production of biomass was severely affected. The effect of various ways of filling the reactor were investigated but no significant effect was found. Lower temperatures reduced the efficiency of the system.