bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oxygen Transfer Efficiency in Counter-and Co-Current Air-Water Flow
Authors: Mavinic Donald S. , Bewtra Jatinder K. 
Published: March 2019

Abstract
This study was undertaken to determine the efficiency of oxygenation in different air-entrained water systems. Both co-current and counter-current air-water flow conditions were used in a closed-loop diffused aeration system, consisting of 4 in. diameter plexiglass U-Tube of variable height and a 4 1/2 × 2 × 1 1/2 ft water re-circulating reservoir at the top.
Four separate systems were investigated: System I was a simple water column; System II used only diffused air for water circulation and for creating an upward co-current air-water flow; System III employed pumping for water circulation, with a control on water velocity such that counter-current air-water flow was maintained; System IV used pumping to circulate water with the water velocity made large enough to create a downward co-current air-water flow. The aeration devices were located at the bottom of one side of the U-Tube in Systems I, II and III and near the top in System IV. The operating conditions were varied by changing airflow rates, water depth, water flow rates, and diffuser location.
The efficiency of different systems is compared in terms of the rate of oxygen transferred/unit power input, given in lb/KWhr. It is found that, within the limitations of this study. System III is the most efficient.
Frequency-Response Approach to Modelling Continuous Reactors
Authors: Melynk P.B. , Norman J.D. , Wilson A.W. 
Published: March 2019

Abstract
It is postulated that the mixing conditions in a flow-through reactor can be characterized as having either completely mixed, completely plug flow, or some network of completely mixed and plug flow component vessels. A frequency-response technique is used to obtain an experimental Bodé plot for arbitrarily mixed vessels. The interpretation of the Bodé plot is discussed, and , in light of this interpretation, a network of plug flow and completely mixed components is specified as a flow model. A Rosenbrock search routine is used to improve the parameter estimates of the model. To verify the model, a second order reaction was run through the vessel and the experimentally measured conversion was compared to that predicted by the model.
It is shown that the modeling technique, in addition to describing the mixing in the system, will indicate inactive volume, as well as measure the extent of any channeling or short circuiting in the reactor.
Water Supply and Waste Disposal for Arctic Communities - A Case Study of Frobisker Bay
Authors: Heinke G.W. , Deans B. 
Published: March 2019

Abstract
The special problems of providing adequate water supply and waste disposal systems for arctic settlements are examined on hand of the community of Frobisher Bay, N.W.T. The two existing methods, a trucked and a piped system, are compared for adequacy, reliability and cost. A series of alternative improvements to upgrade community services are proposed. It was concluded that any of the suggested alternatives up to the level of complete piped services are feasible from engineering and economic considerations.
The Phytotoxicity of Crude Oil Spills in Freshwater
Authors: Hutchinson T.C. , Kauss P. , Griffiths Marta 
Published: March 2019

Abstract
Field and laboratory experiments have been carried out to determine the toxicity to planktonic algae of crude oil, crude oil - water extracts and also selected oil components. Field experiments were performed in a half-acre pond. Localised spills of crude oil were confined within specially constructed floating cylinders with an attached collar. Three different effects of crude oil spills were noted - 1) certain species were inhibited in their growth 2) other species did not appear to be effected and 3) a number of species showed apparent stimulation following the spill. These results emphasize the great differences in response between species and suggest the actual planktonic composition of a water body of considerable importance in predicting the effects of an oil spill.
In laboratory studies the toxicity of the water soluble components of crude oil only were tested. These extracts had a significant effect in increasing acidity of the water, which by itself, reduced algal growth. However, it was found that toxic factors were present, in addition to pH effects. There toxic factors or components appeared to be volatile. Tests with benzene, toluene and xylene - three water soluble crude oil components - showes them all to be toxic, with toxicity increasing in the order indicated.
Anaerobic Digestion of Primary Sludge Containing Iron Phosphate
Authors: Jack M.E. , Farquhar G.J. , Cornwall G.M. 
Published: March 2019

Abstract
The importance of phosphorus as a nutrient in the eutrophication of lakes and rivers has been well established (Fruh 1967). It has been shown in addition that a significant amount of this phosphorus arises from the discharge of treated and untreated municipal wastewater (Task Group Report 1967). Consequently, measures are being taken, notably in the Province of Ontario, for removal of phosphorus from wastewater by means of chemical precipitation. Chemicals exhibiting satisfactory phosphorus removal include lime, iron compounds and aluminum compounds (Leckie and Stumm 1970; Schmid 1968; Wuhrman 1968).
Boundary Effects on Dilution of Buoyant Jets
Authors: Sharp James J. , Wang Chung-su 
Published: March 2019

Abstract
Most studies of buoyant jet phenomena have been conducted with the outfall pipe remote from the bed. This situation idealises the practical case because, over a period of time, it is likely that the diffuser pipeline will settle some way into the bed due to the scour action of prevailing currents. Thus, the dilution achieved in the rising jet may be affected to some extent by the proximity of the ocean bed.
This paper describes an experimental study conducted to determine the effect of a bed immediately below the outfall mozzle. The results indicated generally that the effect of the floor was to considerably increase the surface dilution above the value predicted by current theories and other experiments, in which the nozzle is remote from the floor. The magnitude of the increase varied but could be as high as 1000%.
Although no analytical studies were undertaken visual observations indicated some reasons for the increase of dilution. As the jet was discharged shear stresses between the floor and the jet caused the effluent to cling to the floor in a manner somewhat similar to that of a wall jet. This caused greater momentum exchange at the interface between the jet and receiving fluid and thereby increased dilution beyond that obtained with a free jet.
It has been known for some time that studies of buoyant jets undertaken in quiescent homogeneous receiving fluid considerably underestimate the dilution which will be achieved in practice because of prevailing currents at the outfall site and the possibility of stratification in the receiving fluid. This study indicates that existing theories for buoyant jet dilution may be even more conservative than was previously thought.
Heavy Metal Tolerance in Algae Isolation from Polluted Lakes Near the Sudbury, Ontario Smelters
Authors: Stokes P.M. , Hutchinson T.C. , Krauter K. 
Published: March 2019

Abstract
The phytoplankton flora of lakes close to the Sudbury smelters is poor both in species and in numbers. The lakes have abnormally high levels of several toxic heavy metals, including nickel and copper. Algal isolates were obtained from two lakes which contained up to 3 ppm of nickel and 0.7 ppm of copper in solution. These isolates were found to be tolerant to higher levels of nickel, copper and silver than were laboratory strains. Their growth response to metals in the medium is distinctive and different from that of the lab strains. Lab strains of Saenedesmus and Chlorella stop growing at 0.1 ppm Cu and 0.5 ppm Ni. “Adapted” lake strains of Saenedesmus, however, continue to grow up to 1.0 ppm Cu and 3.0 ppm Ni. “Adapted” strains of Chlorella stop growing at 0.4 ppm Cu. Both of the “adapted” lake isolates showed a gradually decreasing growth rate with increasing concentrations of metals, whereas the lab strains showed total inhibition at a low metal concentration. Lab and lake strains both take up copper. The uptake is linear with concentration in the media. The lake isolates continued growth until a Cu concentration of 2400+ ppm was reached (on dry t. basis). This suggests a mechanism of metal tolerance rather than one of exclusion as means of survival. The ecological implications of these adaptations to high levels of toxic metals are discussed, especially the finding that the tolerant algae are adapted to high silver levels, even though silver is not a pollutant in the lakes.
Phosphorus Leaching from Sewage Sludge Used as Landfill
Authors: Wadehra P.K. , Adelman M. 
Published: March 2019

Abstract
The present experimental investigation has been carried out to study the release of phosphorus in its various soluble forms to rain water or melting snow from sewage sludge used in the landfill type of sludge disposal. An attempt has been made to study methods for reducing the amount of phosphorus being leached out by water.
It has been found that if the sludge is digested anaerobically before disposal, the amount of phosphorus that would be released to water is reduced by 90-95 percent. The addition of ferric chloride or alum further improves the insolubilization of phosphorus, but the improvement is so small that it is not considered advisable to add these chemicals to the sludge for achieving this specific purpose alone. If ferric chloride or alum is added in the previous stages of wastewater treatment, viz., for coagulation, this will further improve the sludge for final disposal.
Some interesting observations were made while studying the fate of phosphorus in its soluble and insoluble forms, during anaerobic digestion of the raw sludge with and without the addition of chemicals.
Wet Air Oxidation of Low Molecular Weight Organic Acids
Authors: Williams P.E.L. , Day D.C. , Hudgins R.R. , Silveston P.L. 
Published: March 2019

Abstract
Wet air oxidation is a process for the oxidation of organic matter dissolved or suspended in water. It operates from 300 to 600 F, usually at pressures of 1000 to 1800 psia. The process is not well understood. This paper reports a kinetic study using propionic and butyric acids. Our research has been directed towards three objectives: identification of the kinetic-control regime; development of a rate equation model, and investigation of the oxidation mechanism. Most of the work was performed using propionic acid. Results with this compound appears to be confirmed by studies using butyric acid. With vigorous agitation, the reaction is kinetically controlled below 550°F and is homogeneous in the aqueous phase. Oxygen attack at the α carbon is suggested by the data. This would account for the high yields of acetic acid. This slowly oxidized acid forms via acetaldehyde. A power law rate expression was developed for the oxidation of propionic acid. Work with butyric acid supports the propionic acid results.
Water Quality Changes at Hydroelectric Dam
Authors: Nelson David A. , Landine Robert C. 
Published: March 2019

Abstract
There is a dearth of information in the literature concerning water quality changes between the headpond and the point where river water emerges from a hydroelectric station. This type of information is required in order to produce continuous water quality models in rivers where there are hydro developments.
This project concerns a study conducted to determine the nature of water quality changes as St. John River water passes through the Mactaquac Hydroelectric Dam.
Samples were collected from points immediately above and immediately below the Dam in each season thereby covering a range of temperature and flow. The samples were analyzed for temperature, biochemical oxygen demand, organic carbon, dissolved oxygen, pH, conductance, alkalinity, hardnesss, tannin and lignin, phosphate, total kjedlahl nitrogen, iron, manganese, copper and zinc.
An analysis of the results revealed that the water quality changes were erratic. On some occasions there were slight increases in parameter values between the upstream and downstream stations and sometimes there were slight decreases.
It is concluded that, for the measured parameters, there is a negligible change in the quality of the river water as it passes through Mactaquac Dam.
Infiltration in Sanitary Sewer Systems: An Overview of Problems in the Halifax-Dartmouth Area
Authors: Gangopadhyay P. 
Published: March 2019

Abstract
Abstract. The paper is composed of two parts. The first part reviews the problem of infiltration of extraneous water in the sanitary sewer systems - its sources, causes and effects are discussed in detail. A systematic approach to the investigation of the problem to pinpoint the sources in an existing system is suggested and outlined. Alternative methods of flow measurements including some recently developed techniques, corrections and remedies of the problem are presented and discussed in detail. The second part deals with the problem in Halifax-Dartmouth area. Results of a number of infiltration studies in this area (some of them were carried out under author's direction) are presented and conclusions drawn.
Distribution of Enteric Bacteria in the Quebec City Section of the St-Lawrence River
Authors: Simard Ronald E. , Zee John A. 
Published: March 2019

Abstract
During the summer of 1973, a survey was made in order to establish the level of enteric bacteria in the sediments and water of the St-Lawrence River. In the sediments, the number of total bacteria, yeast and mold fluctuates from station to station and with the tide. Higher counts of total and fecal coliform were encountered on the north shore than on the south shore resulting from Quebec City sewerage. The number of fecal bacteria decreased when approaching the Gulf and their number was higher at rising tide. The main species encountered were Klebsiella pneumonia, Salmonella enteridis and Escherichia spp.
Chlorophyll and Production in a Polytrophic Marsh
Authors: Harris G. P. , Bacchus H. M. 
Published: March 2019

Abstract
During the period 14 June to 4 October 1973, nitrogen, phosphorus and biomass determinations were carried out twice weekly in the waters of Cootes Paradise, Dundas, Ontario. In the western end of the marsh, biomass values (as chlorophyll a) were as high as 3900 mg/m3 with an average of 700 mg/m3. Total inorganic phosphorus was always in abundant supply ranging in concentrations of 1.2 ppm to 25.00 ppm. There was indication of mining of PO4, ‒P from the sediments of the Desjardins Canal under anoxic conditions. An inverse relationship was found between biomass and total inorganic phosphorus while there was no correlation between biomass and No3 ‒N overall. Average N:P ratios were low, generally less than 0.5. Nitrification of effluent ammonia was shown to be the major source of nitrogen. A periodicity in the effluent ammonia concentration preceeded increases in biomass. Biomass was dominated by Scenedesmus sp. Wind stress was found to have a significant influence on the changes in biomass. Average net production estimates were 1.65 gm O2/m2/hr with a maximum of 3.17 gm O2/m2/hr.
The Dundas sewage plant effluent is the prime source of nutrients, both from the current effluent and from previously settled solids. Biological activity in the marsh is directly related to these periodic nutrient inputs. The west end of the marsh removes 80% of the PO4 before the water reaches the main area and therefore has a vital role to play in controlling the overall water quality of the marsh.
Thermal Effects of Nuclear Power Stations
Authors: Bethlendy G. 
Published: March 2019

Abstract
Even with the latest technology, more than 60% of the heat produced by any thermal engine - whether the fuel is coal, oil, gas or uranium - must be taken back into the environment by cooling water or exhaust gas.
For economical reasons, the usual means of disposing of the “waste” heat from a thermal-power plant is to pump river, lake or sea water through the parts of the plant concerned. Nuclear power plants use their heat as efficiently as older thermal plants, 30–33%. Modern thermal plants, however work with as high as 40% efficiency, and release about 10–13% of their total fuel-heat into the air through the stack. As a result of the combination of all these factors, nuclear power plants release about 68–70% of total input heat into the cooling water.
In practice this means that the plant must be able to draw upon a source of cooling water which is large enough, which flows quickly or is cold enough not to be seriously effected by the return of warmed-up water from the power station. Where this is not possible, it may be necessary to build relatively expensive cooling ponds and/or towers so that the heat is also released to the air rather than only to a local body of water. The thermal effects could be detrimental or beneficial depending on the utilization of the water body.
At the present time the utilities are aware of these problems and very extensive aquatic studies are being made before and after the construction of the plants. Some beneficial uses of waste heat are being sought via research and demonstration projects (e.g. in agriculture, aquaculture, district heating, etc.).
Control Logic for Real Time Control of Flow in Combined Sewers
Authors: Bell W. , Johnson G. , Winn C. B. 
Published: March 2019

Abstract
This paper presents a method for determining an optimal control strategy for the real time control of flow in combined sewer systems. The objective of this control is to minimize weighted flow diversions from the sewer system to the receiving waters during storm periods.
The elements of a control system for combined sewers are described first. This is followed by a development of a reservoir model for combined sewer systems having weir and orifice controls at the regulator structures. An example, verified by the variational calculus, is given of an optimal control strategy that will minimize the weighted overflows from a system of three reservoirs. Examination of this optimal strategy and others presented in the literature shows that the optimal control strategy for this type of problem typically falls on constraint boundaries and includes jumps in the orifice controls from maximum to minimum positions. By formulating these common operating procedures into a set of rules it is shown that if the times at which the jumps in the orifice controls occur are known, then for a given set of inflow hydrographs the control strategy is completely defined. The determination of an optimal control is then reduced to finding the optimal times for the jumps in the orifice controls to occur. A procedure for this optimization is outlined and the results of its application to a system of ten reservoirs are presented.
It is concluded that the method presented for the determination of an optimal control logic would be suitable for a system containing up to twenty control points and would ensure maximum utilization of available system storage capacity.
Parameters for Measuring the Activity and Viability of Activated Sludge
Authors: Nutt S.G. , Murphy K.L. 
Published: March 2019

Abstract
Conventional wastewater parameters are accepted as inadequate estimates of the condition of activated sludge but numerous other indices have been suggested as specific measurements of the activity and viability of the biomass. Literature in the related fields of microbiology and biochemistry were reviewed in order to select the most appropriate activity parameters for application to a heterogeneous biological material. Modified analytical methods were applied to a well-controlled biological system containing a single predominant bacterial species to evaluate the relative merit of each as an indicator of viability and activity. The potential of each parameter in a complex heterogeneous system was determined by monitoring each index in a bench activated sludge system.
The predominant culture studies indicated that the ATP content of the biomass and the dehydrogenase activity were potential indicators of cell viability in a simple system. However, in the complex activated sludge system, only the ATP content showed significant correlation to the organic carbon removal rate.
Process Requirement for Phosphorus Removal at Activated Sludge Sewage Treatment Plants
Authors: Constantine T. A. , Yu K. , Shaffner W. J. 
Published: March 2019

Abstract
The results of bench-scale and full-scale studies for nutrient removal at four activated sludge plants in the City of London were reported. The objective of 1 mg/l of phosphorus in final effluent was met by the addition of ferric chloride or lime. The choice of chemical, the required chemical dosages and the efficiency of phosphorus removal were found to be dependent on the location of the chemical addition point, the hydraulic loading of clarifier and the conditions of the sludge. Pacing of chemical pump by the plant flow signal was found to be satisfactory. Good sedimentation of the phosphate floc was obtained with overflow rate of 600 IGPD/ft2 using lime and over 1000 IGPD/ft2 using ferric chloride. Lime increased the solid content but decreased the volume of the sludge. Ferric chloride did not significantly alter the characteristic of the sludge other than the colour.
Sewage Characterization in the Montreal Area
Authors: Cluis Daniel A. , Couillard Denis , Mascolo Dominique , Meybeck Michel 
Published: March 2019

Abstract
In 1971 a study was carried out in the Montreal area on 34 sewage effluents servicing a population of approximately one million inhabitants. These effluents (15 sanitary, of which 9 were treated; and 19 combined) drained into the rivers “Des Prairies” and “Mille-Isles”.
Each effluent was monitored continuously over a 36 hour period. Discharges were measured every 15 minutes and samples were taken every half-hour. Composite 6 hour samples were analyzed for B.O.D., C.O.D., D.O., Orthophosphates, total phosphates, nitrites, nitrates, chlorides, ABS, total solids and conductivity.
Typical daily per capita loadings were found to be 49 g B.O.D., 117 g C.O.D., and 5.3 g total phosphates. These loadings were based upon a daily sewage rejection of 119 U.S. gallons per capita.
Natural Freezing for Dewatering of Alum Sludge from the Elgin Area Water System
Authors: Todd G. W. , Kosaric N. 
Published: March 2019

Abstract
A review of the current literature indicates that freezing drastically alters the dewatering characteristics of alum sludges. However, the degree of alteration varies among different sludges and consequently laboratory experimentation is necessary to determine its effectiveness in dewatering a specific sludge.
The results of the analyses performed on samples collected from the water treatment plant serving the Elgin Area Water System confirm that natural freezing is a satisfactory method for dewatering the alum sludge produced at this plant.
It would appear that two lagoons, each having a surface area of one and a quarter acres could be constructed to treat the sludge. One lagoon will store the annual volume of sludge discharged from the sedimentation basins and the other will receive the sludge that will be transferred from the first lagoon during the winter months. The freezing and dewatering process would take place in this second lagoon. The clear water obtained after the frozen sludge has thawed would be recycled with the raw water for further treatment.