bluuebunny/crossref_metadata_2025 huggingface dataset:
Anaerobic Digestion of Primary Sludge Containing Iron Phosphate
Authors: Jack M.E. , Farquhar G.J. , Cornwall G.M.
Published: March 2019

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

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

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

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

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

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. 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

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

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

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

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

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

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

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

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.
Some Water Quality Studies in Petroleum Refineries
Authors: Tertipis G. G. , Pyburn C. M.
Published: March 2019

The general approach to water quality studies in Gulf Canada petroleum refineries is described and illustrated by typical results from one refinery. Some of the studies were carried out using a Mobile Water Conservation Laboratory on site whilst others involved grab sampling and transportation to a central laboratory. The studies were carried out with the objective of evaluating the efficiency of existing waste water treating systems to produce effluent of quality which will meet modern environmental requirements set by the Federal Government. These include oil, suspended solids, sulfide, ammonia, phenols, pH and a fish toxicity requirement. The quality of the effluents of several large and complex refineries was monitored, performance of waste water treating units was determined and pilot plant data of new packaged units was collected for future uses. Emphasis was placed on treating units which are used to treat waste streams and effluents for oil and suspended solids removal.
Residual Organics From Bio-Oxidation and Activated Carbon Adsorption of Domestic Wastewater
Authors: Bertrandy M-C. , Murphy K.L. , Benedek A.
Published: March 2019

Organic compounds present in wastewater can be removed by established biological processes or by the recently developed physicochemical process wherein organics in the sewage are adsorbed on activated carbon after coagulation and sand filtration.

In both adsorption and bio-oxidation, residuals have been observed. Theoretically, a combination of both processes should remove these residuals, but to date, evidence is lacking to support this hypothesis. This study evaluated biological and adsorption residuals singly and in combination.
Impact of Dursban and Abate on Microbial Numbers and Some Chemical Properties of Standing Ponds
Authors: Butcher J. , Boyer M. , Fowle CD.
Published: March 2019

Eleven small ponds, lined with polyethylene, were used to assess the consequences of applications of *DursbanR at 0.004, 0.030, 0.100 and 1.000 ppm and AbateR at 0.025 and 0.100 ppm active ingredient.

The treated ponds showed a more pronounced long-term increase in pH and dissolved oxygen and decreasing total and dissolved carbon dioxide in comparison with untreated ponds. Algal blooms were of longer duration in treated ponds than in controls. Total photosynthetic productivity was higher in treated ponds but bacterial numbers did not change significantly. Photosynthetic productivity was estimated by following the changes in total carbon dioxide.
Dewatering Base Metal Mine Drainage Sludge
Authors: Campbell H. , Le Clair B.P.
Published: March 2019

Sludge dewatering studies were carried out at the Brunswick Mining and Smelting Corporation’s No. 12 mill as part of a pilot plant program on the removal of heavy metals from base metal mining effluents. A mobile sludge dewatering trailer located on site was used to assess the feasibility of basket centrifugation, solid bowl centrifugation, vacuum filtration and pressure filtration as possible methods of dewatering. The effect of control variables on performance, and the applicability of existing bench-scale methods to design were studied for each process.

Cake solids of 25% and suspended solids recoveries of 95% were attainable on all four pilot-scale dewatering units. The use of a basket centrifuge may not be practical due to very short cycle times which result from the high sludge feed solids concentration (7%). The addition of cationic polyelectrolyte was necessary to achieve recoveries in excess of 75% with the centrifuges, but was not required with either the vacuum filter or the filter press. The filter press, which produced a filter cake of 38 to 45% and a filtrate quality of 0 to 10 mg/1 of suspended solids, produced the best cake solids and effluent quality. However, the vacuum filter would require the lowest operating cost of units tested.

Bench-scale work included penetration tests, Buchner funnel tests, capillary suction time, leaf filter tests and bench filter tests. Scale-up from bench to pilot plant was not possible for centrifugation with existing methodology. Filter yields and pressing time were predicted from bench tests for the vacuum filter and pressure filter respectively, and compared with the results obtained. Specific sludge characteristics such as zeta potential, particle size distribution and rheology were also determined and related to solids concentration and level of polymer addition.
A Comparison Between the Effects of Sporadic and Continuous Loading From Sulphite Paper Mills on Attached Algae in the Ottawa River Near Ottawa, Canada
Authors: Dickman Mike
Published: March 2019

Attached algal species composition and specific conductivity were monitored above and below two sulphite pulp and paper mills near Ottawa. Continuous monitoring of the river's specific conductivity below the upstream mill revealed sharp peaks at irregular intervals over the summer. These peaks were interpreted as indications of large scale effluent release by the company as they did not occur on the upstream conductivity monitors. Continuous monitoring of specific conductivity above and below a second (larger) sulphite mill revealed a steady release of effluent without large sporadic releases.

The reduction in the total number of periphyton species below each of these pulp mills was similar even though the upstream mill released nearly ten times less effluent than the downstream mill. Furthermore, periphyton species composition and density below the two mills was surprisingly similar even though the larger mill was continuously releasing its effluent. It was concluded that sporadic dumping of concentrated wastes is as harmful to most algal species as continuous release of these same wastes over an extended period of time. Environmental agencies invested with the responsibility of ensuring acceptable water quality conditions should therefore develop a comprehensive network of continuous monitors immediately below major industries which discharge into our lakes, rivers and oceans to discourage industries from shock loading.
Electrolysis of Wastewater - A Laboratory Study
Authors: Wei N.S. , Heinke G.W.
Published: March 2019

This paper presents bench scale experimental results on the electrolysis of raw domestic wastewater. Studies carried out with consumable electrodes are discussed. A mathematical model of a small electrolytic sewage treatment unit for individual household application is developed. The energy consumption and cost of such a device are discussed.

Electrolysis can be described as a process in which chemical reactions are induced at each electro-liquid interface by applying an external electrical energy source to a system of electrodes immersed in a liquid. This paper deals only with electrolysis where a direct current power supply is used as the energy source. The process is governed by Faraday' s two laws on electrochemistry. The fundamental process parameter is the electrical charge density, measured as coulombs per litre (c/1) of wastewater treated.

There are two basic types of electrolysis depending on the choice of anode material.

When the anode is made of dissolvable metallic material such as iron, stainless steel and aluminum, the metal dissolves and goes into the sewage as metallic ions and forms hydrated metallic oxides which act as flocculating agents. The amount of metal dissolved is proportional to the quantity of electrical charges supplied to the system.

Results from a series of batch experiments showed that electrolysis with consumable electrodes is capable of removing significant amounts of organic pollutants. Total organic carbon (TOC) removal was found to be a function of charge density. Phosphate removal efficiency of 90 percent or higher was achieved at a relatively low charge density of 240 coulombs per litre with either iron or stainless steel anodes.

A mathematical model was derived in the conceptual design of a household electrolytic treatment unit. The model incorporates variables such as decomposition voltage of the electrodes and electrical conductivity of the wastewater as well as the physical configuration of the electrolytic cell. The energy requirement of such a unit can be calculated from the model.

It is suggested in this paper that an electrolytic waste treatment unit could be an alternative to the septic tank and tile bed system in areas where the latter is not applicable due to poor soil and terrain conditions.
Dual-Media Filtration for Treatment of Refinery Waste Water
Authors: Michniewicz T.E. , Kempling J.C. , Eng J.
Published: March 2019

Waste water from refinery process units contains entrained oil and suspended solids which must be removed prior to discharge of the water. Primary gravity separation by an API separator reduces the oil and suspended solids concentrations. However, further treatment is usually required to make the water amenable to secondary treatment. Filtration is one of several processes which can be used in this service.

Pilot studies were made on site at an Imperial Oil refinery. The filter media consisted of a 2 ft. depth of anthracite on top of a 1 ft. depth of sand. The filtration rate was varied and the filter was operated downflow with gravity flow. The average oil and suspended solids reductions were 75% and 55%, respectively. Run lengths of 15 to 40 hours were observed (depending upon feed quality) before backwashing was required and the amount of backwash water was 1 to 2 vol % of the water filtered.

Based on these pilot data, a dual-media filter was constructed at an Imperial Oil refinery to treat 6,000 US gal/min. Data from the first year of operation show a very good agreement with the design values. The average percentage reductions of oil and suspended solids were 79% and 54%, respectively. The average effluent oil concentration is less than the design target. The filtration cycle length is 13 hours due to a slightly higher suspended solids in the feed than expected. No deterioration of the filter media has been observed with time. The backwash is treated by chemical flocculation to reduce its volume and the sludge is disposed of by incineration.
Application of Hyodrologic and Water Quality Models For Preliminary Screening of Urban Development Alternatives
Authors: Wisner P.E. , Jalal K.F. , Roake A.F. , Torrens L.
Published: March 2019

In this paper, several applications of STORM and SWMM are summarized in order to illustrate some of the potential uses of these models, and their role in a general planning study is discussed.
Relationships Between Soluble and Sediment Nutrient Losses, Land Use and Types of Soil in Agricultural Watersheds
Authors: Neilsen G.H. , Mackenzie A.F.
Published: March 2019

Seven agricultural watersheds in southwestern Quebec and southeastern Ontario, ranging in area from 2,000 to 20,000 hectares, were monitored systematically during 1973–75 for soluble inorganic nitrogen, total soluble phosphorus, calcium, magnesium, potassium, sulfate-sulfur, chemical oxidation demand, discharge, suspended sediment concentration, sediment Kjeldahl nitrogen, Bray extractable phosphorus, and ammonium acetate extractable calcium, magnesium and potassium.

For 1974–75, annual Kg/ha, loss rates were calculated for the soluble and sediment associated nutrients. Losses varied with nutrient and watershed, with volume of runoff being an important control of nutrient loss variation. Significant amounts of SO4−S in precipitation were suggested by an average watershed soluble N:P:S loss ratio of 10:1:92. Sediment nutrient losses were especially important for N and P, comprising over 40% of their total loss. The importance of spring snow-melt runoff was demonstrated by the high proportion of all nutrients lost at this time. Correlations of nutrient loss, land use and soils suggested that certain land uses resulted in increased stream nutrient losses while increased watershed area of soils with a high surface runoff potential was particularly conducive to increased soluble nutrient and sediment losses.
Chemical and Biological Changes in Nelson Lake, Ontario Following Experimental Elevation of Lake pH
Authors: Yan N.D. , Scheider W.A. , Dillon P.J.
Published: March 2019

Intensive studies of Nelson Lake, a Sudbury area lake of intermediate pH ~5.7), were begun in 1975. The chemistry of the lake was typical of that of most PreCambrian Shield lakes except that low alkalinities and high sulphate concentrations were observed along with elevated heavy metal levels.

After raising the pH of Nelson Lake to 6.4 by addition of Ca(OH)2 and CaCO3, the metals were reduced to background concentrations. Phytoplankton and Zooplankton communities, which at pH of 5.7 were typical of PreCambrian lakes, were not affected by the experimental elevation of lake pH.
Small-Scale Variations in Precipitation Loading Near Dorset, Ontario
Authors: Jeffries D.S. , Snyder W.R. , Scheider W.A. , Kirby M.
Published: March 2019

A five station network of on-lake precipitation collectors was established in 1976 on Red Chalk Lake, a small Precambrian shield lake near Dorset, Ontario. Collection of bulk precipitation (wet and dry fall) on an event basis was carried out during spring, summer, and fall of 1976 and 1977. Chemical analyses of pH, nutrients, and major ions were performed and loadings calculated. Two-way analysis of variance showed that significant variance in precipitation depth and chemical loading occurred between sample period but not between stations. The same result was obtained when the Red Chalk stations were compared to a similar station located on Harp Lake, 25 km. to the northwest. Comparison of the Red Chalk on-lake stations with 6 additional stations placed in the watershed showed significant variation between the on- and off-lake sets and between the individual off-lake stations themselves.
Removal of Trace Heavy Metals from Sewage Using the Lime-Magnesium Process
Authors: Oldham W.K. , MacLean B.H.
Published: March 2019

The research described in this paper is directed toward optimizing conventional lime precipitation of heavy metals by the addition of small quantities of magnesium. Specifically, jar tests were performed to evaluate the effectiveness of adding various concentrations of Mg2+ to both raw sewage and primary effluent to improve the precipitation of metal ions at various reaction pH values. The desired pH levels (10.0, 10.6 and 11.4) were obtained by the addition of lime.

General results of the study, using Cr3+, Cu2+, Pb2+, Ni2+ and Zn2+ in concentrations of 0.5, 2.5 and 5.0 mg/l, indicated the following:

1. as expected, the higher the reaction pH, the greater the removal efficiency;

2. for a given reaction pH, the presence of some added Mg++ increased the removal efficiency for all metals tested except Ni2+;

3. on the average, a lime dosage of 220 mg/l (reaction pH=10.6) coupled with an Mg2+ concentration of 30 mg/l, give equivalent removals to high lime treatment at 400 mg/l (reaction pH=11.4);

4. the removal efficiencies varied between 10% and 35% for Ni2+, while the other metals gave results of 35% to 95%, depending upon treatment conditions.

It can be concluded that the addition of Mg2+ does indeed enhance the removal of many heavy metals although more work is needed to optimize the combinations for a given type of sewage and to subsequently investigate relative economics.
Sewage Disposal and Viral Pollution of the Ottawa River
Authors: Sattar S.A. , Springthorpe V.S. , Ramia S.
Published: March 2019

The quality of water in the Ottawa River is being affected by the disposal of increased volumes of sewage into it. Some of the sewage disposal points are situated upstream of beaches and intake points for water purification plants. The aim of this study was to assess the impact of such waste disposal on the virological quality of recreational and drinking waters for the Ottawa area. A total of 132 weekly samples of raw sewage, chlorinated secondary effluents, raw and finished surface waters were examined for viruses from June to December 1977. In addition to these, ten samples of tap water, collected during the first two weeks of April 1978, were also included in this study. Virus concentration from these samples was carried out using the talc-Celite technique developed in the laboratory. Primary human embryonic kidney (HEK) cells and BS-C-1 cells were used for the detection and quantitation of viruses present in the sample concentrates. Virus isolates were identified by their cytopathology, examination under the electron microscope and serology.

When 6 1. volumes were processed, nearly all the samples of raw sewage and 54% chlorinated effluent samples were found to be positive for virus. Approximately 50% of the surface water samples were also shown to contain virus using 40 1. sample volumes. Concentrates of some of the potable water samples showed virus-like degeneration in cell cultures. Although this degeneration was found to be transmissible, at this stage it is not possible to say if this effect was in fact due to a viral agent.

The following major conclusions were drawn from this study:

(a) All three major enteric virus groups were represented in the virus isolates. However, inherent limitations of sample concentration and virus isolation techniques may have resulted in the detection of only a small fraction of the viruses present in the samples.

(b) There was no apparent correspondence between the numbers of indicator bacteria and the presence or absence of detectable virus in the samples.

(c) Viruses detected in the recreational and raw water samples may be due to the presence of point sources of raw sewage discharge upstream. This could result in the dissemination of human pathogenic viruses through recreational and potable waters.
Investigation of the Contribution of Natural Organic Runoff to Dissolved Oxygen Depletion in the Red Deer River
Authors: Penttinen S.E. , Bouthillier P.H. , Hrudey S.E.
Published: March 2019

Studies on the chronic low dissolved oxygen problems encountered under winter ice in the Red Deer River have generally been unable to account for dissolved oxygen depletion in terms of known manmade inputs. An experimental program was developed to assess the possible nature and approximate bounds of oxygen demand due to natural organic runoff carried to the Red Deer River by a small tributary stream, the Blindman River. The study employed an electrolytic respirometer on stream water samples subjected to prior concentration by vacuum evaporation.

Evaluation of carbon and nitrogen budgets in conjunction with the measured oxygen demand indicate that biochemical oxygen demand is originating with natural organic runoff in tributaries of the Red Deer River. The results provide a basis for estimation of the possible contribution to the observed oxygen demand in the Red Deer River originating from natural organic runoff.
Effets de sel sur l'extraction du phenol par solvants mixtes
Authors: Gravelle D.V. , Panayiotou C.
Published: March 2019

L'extraction du phénol de l'eau fut effectuée à l'aide des solvants mixtes n-octanol-acétate de butyle, n-octanol-éther isopropylique et benzène-éther isopropylique. Ces solvants semblent les plus prometteurs pour l'extraction du phénol à cause de leurs effets combinés de synergie et de relargage. Bien que les coefficients de partage du phénol soient plus élevés pour le solvant n-octonal-acétate de butyle, ce solvant se classe dernier en terme d'efficacité d'extraction sur une colonne à plateaux vibrants. Cependant, la présence d'un sel dans la phase aqueuse peut améliorer l'efficacité du solvant pour extraire le phénol.
La caracterisation de la performance du procede de boues activees par la variable carbone
Authors: Thérien N. , Perdrieux S.
Published: March 2019

L'analyse des différentes formes du carbone et en particulier la mesure de la concentration du carbone organique soluble et du carbone organique en suspension des divers écoulements d'une unité pilote de laboratoire pour le procédé des boues activées a été faite. Cette analyse, réalisée pour des conditions d'opération transitoire, a permis l'identification expérimentale de phénomènes établis dans la littérature courante mais rapportée en termes de mesures plus conventionnelles tels que la DBO5, la DCO et les SSV.

L'utilisation de la variable carbone pour un substrat synthétique puis pour une liqueur industrielle a montré que celle-ci est apte à décrire le comportement dynamique d'un tel procédé soumis à des perturbations réalistes à la fois dans la quantité et la qualité du substrat organique alimenté au procédé.
The Role of Protozoa in High Rate Wastewater Treatment Systems
Authors: Booth R. , Henry J.G. , Prasad D.
Published: March 2019

Three continuous, laboratory scale, high rate biological wastewater treatment systems operating in a similar mode were evaluated. The feed was a synthetic sewage with a COD and BOD of approximately 300 mg/l and 200 mg/l, respectively. The total hydraulic retention time in each system was 2-1/4 hours - 40 minutes aeration, 95 minutes sedimentation. The applied food to microorganism ratios (F/M) were equal to or greater than one. Systems I and II employed a single aerobic reactor whereas System III employed two aerobic reactors in series each with a hydraulic retention time of 20 minutes. Sludge was returned to the second reactor only, thus establishing dispersed growth in the first reactor and a mixed microbial population in the second. System I was strictly a bacterial system isolated from atmospheric contamination. System II employed a mixed population of ciliated protozoa and bacteria.

Tests performed included soluble COD reduction, effluent, mixed liquor and return sludge suspended solids, SVI, pH, polysacharides, bacteria count, and protozoan count. Comparison of System I (bacterial) and System II (mixed population) revealed an improvement in effluent quality (SS, Total COD) as a result of the presence of ciliated protozoa. The higher effluent SS in System I was a result of the poor settleability of dispersed growth.

Based on the knowledge of the effects of protozoa on dispersed growth, System III (bacterial reactor and mixed population reactor in series) was established to determine if such a series arrangement would further improve treatment efficiency. Several different two stage reactor system configurations were investigated including sedimentation after the first reactor with the effluent passing to the second reactor. Such an arrangement proved impractical due to the poor settleability of the dispersed growth associated with a predominantly bacterial system. System III resulted in a vast improvement in sludge settleability while maintaining an effluent quality equal to that of System II. This improvement in sludge settleability indicates improved system stability and reduced handling costs.
The Fugacity Approach for Calculating Near-Source Toxic Substance Concentrations and Partitioning in Lakes
Authors: Mackay Donald , Paterson Sally
Published: March 2019

There is an obvious incentive to develop the capability of calculating the concentration of toxic substances in the water column, sediments, and biota in lakes as a function of the emission rate, the substances' partitioning and reaction properties, and the lake hydrodynamics. The fugacity approach is reviewed briefly as a method of calculating (i) the mass balance, (ii) partitioning and rates of exchange with air, biota, and sediment, (iii) advective loss, and (iv) degradation processes for a specimen toxic substance. The further problem of calculating concentration distribution in the lake as a result of locally high emission rates is treated and it is suggested that the methodology may be used to calculate concentrations in such near-source zones which may be designated for limited use as a result of relatively high levels of contamination.
Deep Shaft High Rate Aerobic Digestion: Laboratory and Pilot Plant Performance
Authors: Tran F. , Gannon D.
Published: March 2019

The Deep Shaft process, originating from ICI Ltd. in the U.K., has been further developed by C-I-L Inc., Eco-Technology Division into an extremely energy efficient, high rate biological treatment process for industrial and municipal wastewaters. The Deep Shaft is essentially an air-lift reactor, sunk deep in the ground (100 - 160 m): the resulting high hydrostatic pressure together with very efficient mixing in the shaft provide extremely high oxygen transfer efficiencies (O.T.E.) of up to 90% vs 4 to 20% in other aerators. This high O.T.E. suggests real potential for Deep Shaft technology in the aerobic digestion of sludges and animal wastes: with conventional aerobic digesters an O.T.E. over 8% is extremely difficult to achieve. This paper describes laboratory and pilot plant Deep Shaft aerobic digester (DSAD) studies carried out at Eco-Research's Pointe Claire, Quebec laboratories, and at the Paris, Ontario pilot Deep Shaft digester.

An economic pre-evaluation indicated that DSAD had the greatest potential for treating high solids content primary or secondary sludge (3-7% total solids) in the high mesophilic and thermophilic temperature range (25-60°C) i.e. in cases where conventional digesters would experience severe limitations of oxygen transfer. Laboratory and pilot plant studies have accordingly concentrated on high solids content sludge digestion as a function of temperature.

Laboratory scale daily draw and fill DSAD runs with a 5% solids sludge at 33°C with a 3 day retention time have achieved 34% volatile solids reduction and a stabilized sludge exhibiting a specific oxygen uptake rate (S.O.U.R.) of less than 1 mgO2/gVSS/hour, measured at 20°C. This digestion rate is about four times faster than the best conventional digesters. Using Eco-Research's Paris, Ontario pilot scale DSAD (a 160 m deep 8 cm diameter u-tube), a 40% reduction in total volatile solids, (or 73% reduction of biodegradable VS) and a final SOUR of 1.2 mg02/gVSS/hour have been achieved for a 4.6% solids sludge in 4 days at 33°C, with loading rates of up to 7.9 kg VSS/m3-day.

Laboratory runs at thermophilic temperatures (up to 60°C) have demonstrated that a stabilized sludge (24-41% VSS reduction) can be produced in retention time of 2 days or less, with a resulting loading rate exceeding 10 kg VSS/m3-day.
Application of a Dispersion Model to Oil-Based Pollutants in the Strait of Canso, Nova Scotia
Authors: Aytimur T. , Chen B.H. , McMillan A.F.
Published: March 2019

A three-dimensional model of mass dispersion with advection was examined with regard to a potential discharge of a large amount of oil pollution in the Strait of Canso, Nova Scotia. A mathematical model of these calculations has been used (Cleary et al. 1973) to predict the temperature distribution in a river due to the heated effluent discharge from a power plant. With a source and an advective term, the three-dimensional diffusion equation for a rectangular channel has been employed with zero-gradient, i.e. impermeable, boundary conditions at the shores, bottom and the surface of the Strait. This system, which is suitable for treating heat and mass dispersion problems in a river, should give acceptable results for a closed channel such as the Canso Strait if we confined our attention to the region sufficiently far away from the Causeway, where the flow velocity is not affected by the Causeway boundary and hence remains constant with spatial variations, and where it is also most likely that an oil spill event may occur.
Treatment of Landfill Leachate by Anaerobic Filter: Part I: Laboratory Studies
Authors: Henry J.G. , Prasad D. , Sidhwa R. , Hilgerdenaar M.
Published: March 2019

Widespread use of sanitary landfills for the disposal of solid waste and recognition of the serious pollution potential of leachate emanating from these landfills have forced municipalities to consider the treatment and safe disposal of this liquid waste. Limited studies conducted at relatively high temperatures (25-35°C) have established that the anaerobic filter process is more economical and effective for the treatment of leachate than other biological systems. However, there seems to be no information on the efficiency of anaerobic filters at lower temperature for the treatment of leachate.

Laboratory studies were carried out over a period of 6 months to evaluate the anaerobic filter process for the treatment of leachate (COD 2,000 mg/L, BOD/COD ratio 0.5) at low temperature (10 and 25°C) . Studies on the digestion of leachate were conducted in two separate units (vol. 6.0 L) at 10 and 25°C. The hydraulic detention times were 6, 12, 24, 48 and 72 hr.

Results indicated that partially stabilized leachate (i.e. from old landfills) can be treated anaerobically at low temperatures (10°C). Up to 90% of the influent COD was removed at 10°C with a 72-hr detention time and at 25°C with a 12-hr detention time. The average total gas production was 400 and 425 L/kg COD destroyed at 10 and 25°C, respectively.