bluuebunny/crossref_metadata_2025_split huggingface dataset:
Disinfection of Drinking Water Rich in Bromide with Chlorine and Chlorine Dioxide, While Minimizing the Formation of Undesirable By-Products
Authors: Rav-Acha Ch. , Serri A. , (Goldstein) Choshen E. , Limoni B. 
Published: May 2018

Although chlorine dioxide does not form trihalomethanes (THM) and produces very few non-volatile haloorganic materials in drinking water, intensive investigations bearing on the formation of chlorite by ClO2 disinfection reveal that the rate of chlorite formation reflects the rate of ClO2 consumption and as long as the amount of ClO2 applied is behind its demand, about 60% of the chlorine dioxide consumed is converted into chlorite.
Mixtures of Cl2 and ClO2, which may successfully reduce the formation of haloorganic compounds, as well as of chlorite in the absence of bromide, fail to do this where water rich in bromide is concerned. As a result of bromide oxidation by chlorine, bromine is formed, which in turn reacts more intensively with organics than does chlorine and thus favours the formation of THM and other halogenated organic materials.
This problem can, however, be circumvented if ClO2 is allowed to react in water with the organic precursors before chlorine is introduced. A pre-treatment with 1 ppm of ClO2 two hours before the application of 2 ppm Cl2, was found to reduce the formation of THM by 60% relative to its formation by chlorine alone, and the chlorite is reduced in this case by up to 90% relative to its formation by chlorine dioxide alone.
This is of particular importance since it can solve some of the major problems bearing on the impact of disinfection upon the formation of undesirable by-products.
Continuous, Automatic Detection of Organophosphates and Carbamates in Water Utilizing Enzyme Microcalorimetry
Authors: Morgan W S. G. , Kühn P. C. , van Niekerk P. P. 
Published: May 2018

An enzyme calorimetric method, employing immobilized cholinesterase to detect harmful levels of organophosphorus and carbamate insecticides in water, is described.
Immobilized cholinesterase activity was assessed automatically in a microcalorimeter by analyzing its catalytic efficiency in hydrolyzing a substrate solution which was passed over the enzyme at regular time intervals. A microcomputer was used to automate the procedure and for data acquisition.
The inhibitory effects of three organophosphorus and two carbamate pesticides upon cholinesterase were studied in order to evaluate the efficacy of the technique.
Hexavalent Chromium Removal from Drinking Water
Authors: Philipot J. M. , Chaffange F. , Sibony J. 
Published: May 2018

A series of tests were performed with a view to solving the problem of chromium pollution in the Meulan district near Paris, due to the proximity of long-established metal-working plants. It was found that the accumulated pollution not only originated from the groundwater source but also from atmospheric contamination through fall-out from smoke and fumes issuing from local metal-works' stacks. Among the interesting features of this paper is the fact that, since the profound penetration by the pollutant affects potable feedstock, chromium removal studies have been made on potable water for the first time on record.
Several methods are reviewed, among which the only economically feasible one appears to be the reduction of hexavalent chromium by a sufficient quantity of iron sulphate, the problem attached to iron-sulphate overdose being solved by the application of high-rate filtration on very fine sand. This arrests the fine precipitates and reduces the residual ferrous-iron by catalysis. Reliability of the treatment is ensured by a system of continuous metering that automatically controls reagent dosing.
Polyphosphate Kinase Activity during Phosphate Uptake by Bacteria
Authors: T'Seyen J. , Malnou D. , Block J. C. , Faup G. 
Published: May 2018

Polyphosphate kinase, one of the key enzymes for polyphosphate accumulation in bacteria, has been investigated in pure culture and activated sludge samples. Three bacterial species (Acinetobacter lwoffi, A. phosphadevorus and Pseudomonas fluorescens) appeared to have a polyphosphate kinase activity (between 0.3 and 4.7 nM of P04 transferred per minute and per mg of proteins). However tests carried out on Aeromonas hydrophila, Bacillus subtilis, E. coli and Serratia sp. showed these species did not have any measurable polyphosphate kinase activity.
Enzyme activity in bacteria is dependent on environmental conditions and can be induced, in particular, by anaerobic stress, even without modification of extracellular phosphate concentrations. Most of the activated sludge samples taken from laboratory pilot plants achieving good phosphorus removal did not present any measurable polyphosphate kinase activity. Such poor results can be related to low numbers of phosphorus removing bacteria and inhibitory molecules in sludge extracts. The only observed activity was in pretreated sludges (washed sludges) and in sludges submitted in a batch reator to phosphate starvation. However, in these, enzyme activity was at least 20 times lower than those measured in pure culture of A. lwoffi.
Polyphosphate kinase induction is a complicated and time consuming method which has to be used only in the research field. At the present time our results show that sludge phosphate uptake potential cannot be predicted by the measure of induction of polyphosphate kinase activity.
Design Strategies for Nutrient Removal Plant
Authors: Barnard James L. , Stevens Gerry M. , Leslie Patrick J. 
Published: May 2018

The first full-scale Bardenpho plant in the colder regions of North America was constructed in Kelowna and operated for about two years. The design was based on criteria developed by Barnard (1974) and based on experience of the design of similar plants in South Africa. Maximum flexibility leaving the operator many options for optimization was allowed. Effluent ortho-phosphate, nitrate and ammonia concentration averaged 0.43, 2.05 and 0.78 mg/ℓ respectively over the first year of operation. Operating results are compared with design predictions. Some results are presented and the design was tested using theories developed by Ekama et al (1984) whose models predicted that no phosphate removal would be possible.
RESUME
La premierè installation de Bardenpho, à grande échelle dans les régions les plus froides de l'Amérique du Nord a été construite à Kelowna et utilisée pendant plus de deux ans. Le dessin était fondé sur les information de Barnard (1974) et basé sur l'expérience du dessin d'installation sembables en Afrique du Sud. L'installation était flexible et laissait à l'opérateur le choix de plusieurs options pour l'optimisation. La concentration de ortho-phosphate, nitrate et ammoniaque avait les valeurs moyennes de 0,43; 2,05 et 0,78 mg/ℓ respectivement pendant la premiére année de travail. Les resultats sont presentés et la dessin a été mis à l'épreuve en utilisant les théories développées par Ekama et al (1984) dont les modèles ont predit. qu' aucun élimination de phosphate serait possible vu le petit réduction de nitrate qui le modèle ont prédit aux températures plus froides.
Water Treatment by Means of Activated Carbon, Prepared from Locally Available Waste Materials (II)
Authors: Keirsse H. , Van Hoof F. , Janssens J. , Buekens A. 
Published: May 2018

Man's natural water supplies are threatened by a large number of nonbiodegradable and toxic organic compounds. Proper environmental standards often can only be attained using tertiary treatment processes, such as adsorption on activated carbon. The latter is an expensive process, owing to the initial cost of activated carbon and the losses occurring during regeneration. Methods are being investigated at the Free University of Brussels for producing and activating carbon, using various types of waste as a raw material.
Following materials have already been used : cacao hulls, sawdust, fruit stones, bark, and waste tyres. Both carbonization and activation have been conducted under the carefully controlled conditions of a fluidized bed reactor. The influence of the following process parameters has been investigated : pyrolysis temperature and time, activation temperature and time, and composition of the furnace atmosphere. The resulting activated carbons should exhibit the following qualities : high adsorption capacity and rate, good resistance to attrition, and possibility of regenerating the carbon. The properties of the carbon obtained have been evaluated by means of a number of standard tests (Iodine-index, BET-surface, Tannin-index, Methylene blue-index, and Phenol-index), and adsorption isotherms of phenol, pentachlorophenol, p. toluene sulphonate and dodecyl benzenesulphonate. In general the properties of the carbons obtained were comparable to those of commercial qualities.
Some of the activated carbons tested will soon be evaluated using synthetic and real phenolic industrial wastewaters (1.5 % of phenol).
The Self-Purification Capability of Karst Underground Watercourses with Respect to the Pollution of the Mediterranean Sea
Authors: Preka N. , Preka-Lipold N. , Avdagic I. , Kurpjel B. 
Published: May 2018

This paper has reviewed the results of the organic selfpurification process that occurs in karst underground watercourses. The investigations were carried out in two test reaches between 1974 and 1984.
The first reach comprised the underground section of a river in an area of shallow karst in Slovenia, while the second one was in the deep karst area of Eastern Herzegovina.
The fundamental studies of the change in the BOD loadings showed the value of the oxygen consumption rate coefficient in karst groundwaters, transferred to a temperature of 20° C, to be k1 (r) = 0.160 to 0.210. To determine the change in loadings, the Upstream - downstream method was applied, while the travel time was defined by using a tracer. An identical value of the deoxygenation coefficient was found when observing the changes in the daily loads at the exit profile only. This knowledge enables the practical application of coefficient k1 to estimate the input organic load in karst catchment areas, and also to define the required level of karst springs and coastal sea protection.
Effect of Sunlight on Coliphages in an Oxidation Pond
Authors: Ohgaki Shinichiro , Ketratanakul Awrapin , Prasertsom Uthaiphun 
Published: May 2018

Escherichia coli B were used as host cells for isolation and multiplication of coliphages. The coliphages were isolated from a small canal which receives the effluent from an oxidation pond in Bangkok, Thailand, and were used as a virological indicator. Coliphages were assayed by the plaque forming technique (PFU method). The coliphage which was used in this study had no resistance to acid (pH3) and weak resistance to alkali (pH 10).The fate of coliphages in the oxidation pond was investigated by field measurement and laboratory experiments.
Batch experiments showed the adsorption of coliphage to microbial particulates (mainly algae) occurred under aerobic conditions. The desorption of coliphage from the particulates was observed under anaerobic conditions. The adsorption-desorption process was reversible and was controlled by dissolved oxygen concentration. The same mechanism of adsorption-desorption was observed in the oxidation pond as well. During day-time, the concentration of coliphage decreased under high concentration of dissolved oxygen caused by photosynthesis. On the other hand, the concentration of coliphage increased after sunset because the dissolved oxygen concentration in the pond decreased to zero due to respiration of algae.
The degree of removal of coliphage in the oxidation pond (design retention time = 20 days) was 90% (1 log). Field measurement with submerged bottles in the oxidation pond and sunlight-exposure experiment using beakers showed that coliphage could be inactivated by sunlight only near the water surface (less than 10 cm depth, the highest estimate) in the oxidation pond.
Drinking Water Transmission of Giardiasis in the United States
Authors: Akin E. W. , Jakubowski W. 
Published: May 2018

For about a century after Giardia was named by Lambl in 1859, the occurrence of the organism in humans was not widely considered significant in explaining the etiology of disease. This organism is now recognized as a cause of disease that ranges from mild to severe and debilitating gastroenteritis. Beginning in 1965, drinking water became increasingly implicated as an important route of transmission. An outbreak occurred in a Colorado ski resort in that year. A survey of visitors to the resort revealed that 123 persons experienced acute enteritis, possibly giardiasis. Sewage contamination of the well water supply was thought to be the source of the organism.
Further evidence for waterborne transmission of Giardia came in 1975 with the first isolation of the organism from a water supply implicated in an outbreak. A cyst was isolated from the water supply during an extended outbreak that resulted in 359 confirmed cases over a 7 month period. Subsequent outbreaks have clearly established the role of water in Giardia transmission. From 1965 through 1984, 90 waterborne outbreaks with 23 776 cases of giardiasis were reported in the United States. This report discusses the etiologic agent and examines drinking water outbreak occurrence and control.
Mersey Estuary (U.K.) Bird Mortalities – Causes, Consequences and Correctives
Authors: Wilson K. W. , Head P. C. , Jones P. D. 
Published: May 2018

In late 1979 there was an extensive mortality amongst the newly arrived over-wintering populations of waders, wildfowl and gulls in the Mersey Estuary. Mortalities on this scale were unprecedented in the area and there was no obvious cause although circumstantial evidence collected during the months following the incident indicated the probability of acute poisoning by trialkyl lead compounds.
The principal source of trialkyl lead compounds was the discharge to the Manchester Ship Canal from a factory producing tetraalkyl lead petroleum additives. Under certain conditions of freshwater flow and tidal movements appreciable concentrations of trialkyl lead could occur in the adjacent waters of the Mersey Estuary. The persistence of trialkyl lead in the estuarine waters provided a suitable source for its up-take by benthic fauna and subsequently birds in amounts similar to those shown to be acutely toxic in laboratory experiments.
Simple empirical models were used to calculate an appropriate effluent quality standard to protect waders and wildfowl. Full co-operation was received from the factory concerned and the levels of trialkyl lead discharged have been reduced to the standard. Levels of alkyl lead in the water and in estuarine fauna have fallen in line with the reduced discharge. No bird mortalities attributable to alkyl lead have been observed since the lower discharge levels have been consistently achieved.
Transport and Water Quality Modelling in the Southern North Sea in Relation to Coastal Pollution Research and Control
Authors: van Pagee J. A. , Gerritsen H. , de Ruijter W P. M. 
Published: May 2018

Mathematical modelling techniques are used to quantify the transport in the southern part of the North Sea of pollutants originating from various inputs. Special attention was given to the anthropogenic increase in local concentrations of nutrients (N, P) and heavy metals (Cd, Hg, Cu, Pb, Zn, Cr) and their potential impact on marine organisms.
A depth-averaged hydrodynamic model is used to calculate tidal and wind driven velocities and water levels. By averaging, residual flows are calculated, forming the basis for advective transports in a water quality model. Dispersive transports are derived from a comparison of simulated and observed salinity distributions. Water mass distributions and age functions for various inflowing water types are determined with the model. Transports of nutrients and heavy metals in the southern part of the North Sea are calculated using annual pollution inputs for 1980. Although interactions with bottom sediments are not considered, the calculated and measured concentrations show good similarities.
The water quality in the Dutch coastal zone and German Bight area is shown to be highly determined by local pollution loads from the rivers Rhine, Weser and Elbe respectively. Comparison of simulated concentrations for 1980 with those resulting from simulations with estimated natural river inputs, shows that more than 50% of nutrients and heavy metal concentrations originate from human activities in large coastal zone areas. From toxicological information and standards, it is concluded that Cd, Hg and Cu are substances that need special attention in pollution research and control for the Dutch coastal waters.
Oxygen Depletion Modelling, Port Shelter, Hong Kong
Authors: Krogsgaard Jensen J. , Malmgren-Hansen A. , Mortensen P. 
Published: May 2018

In order to describe and evaluate the effect on the oxygen concentrations of a planned sewage outlet in the Port Shelter Bay in Hong Kong, a relatively simple BOD-DO-box model has been established. The model describes the oxygen concentration in 6 horizontal boxes in the central part of Port Shelter. Each box is vertically divided into 4 layers (sub-boxes). The oxygen concentration in each layer is described as a function of the vertical and the horizontal mixing, the oxygen demand of the sediment and the concentration of organic matter in the water. A finite difference transport dispersion model provided input data for the BOD-DO model.
Two main calculations have been made: one simulating the cold season (15°C) and one simulating the warm season (30°C). Furthermore sensitivity analyses have been carried out.
The calculations show an oxygen depletion of approximately 1 and 2 mg O2/l at 15° and 30°C respectively in the bottom layer over an area of approximately two sq. km. The highest oxygen depletion is calculated in the bottom layer. From the calculation it can further be concluded that the decay rate of organic matter in the water and the vertical mixing will influence the oxygen depletion considerably. In periods where either the decay rate is higher than 3 d−1, or the vertical mixing is considerably low an oxygen depletion higher than the calculated can be expected. The lowest measured oxygen concentration in Port Shelter during the period July-August 1982 was 1.7 mg O2/l. Therefore it can be expected that the planned outlet will cause oxygen-free or nearly oxygen-free conditions in the bottom layer in warm periods with low vertical mixing.
Simultaneous Nitrogen and Phosphate Removal by the Intermittent Cyclic Process
Authors: Hayakawa N. , Tsuji J. , Hamamoto Y. 
Published: May 2018

By using the Intermittent Cyclic (IC) process which repeats aerobic and anaerobic conditions in an 18-m3 pilot plant reactor, domestic sewage was treated at a rate of 18 m3 per day. Operating condition was 4 cycles per day, intermittent aeration--4 hours, settling--1 hour, drawing--1 hour.
Seven months of operation recorded high nitrogen removal rates: mean 86% and maximum 96%, phosphate removal rates: mean 83% and maximum 93%. Compared with conventional aerobic/anaerobic processes, the IC process, one of batch-type treatment processes, can advantageously and stably remove nitrogen and phosphate with repeated aeration and nonaeration under optimal control.
Legal Aspects of the Disposal of Industrial Wastes on Soil
Authors: Mendes J M. O. 
Published: May 2018

It is, clearly, a Government responsibility to enact laws and promulgate regulations for control of industrial pollution.
The main techniques for soil industrial wastes disposal, namely, landfarming and landfilling, profit from the extensive knowledge acquired, in past decades, in the field of water and air pollution control and must be analysed within a comprehensive system for hazardous waste management, with its legal and administrative aspects.
This paper presents some general principles of a Hazardous Waste Management System, which are broadly applicable, regardless differences between States or Countries. Finally, it discusses the specific case of Hazardous Wastes Management in the State of Bahia, Brazil and makes some suggestions for its improvement.
Comparison between a Perforated Pipe and a Fixed Sprinkler System for Land Disposal of Treated Petrochemical Effluent
Authors: Simon Zeno , Baldasso Mario L. , Gazen Adejalmo F. , Aguirre Juan C. 
Published: May 2018

At SITEL – the integrated effluent treatment system of Pólo Petroquímico do Sul (South Petrochemical Complex, Triunfo, Brazil) – the tertiary-treated effluent is disposed of on land at an average hydraulic application rate of 140 m3/ha.day. Two subsystems have been installed in order to minimize the devastation of indigenous vegetation during the construction phase, aiming also at investigating the cheaper processes to be adopted when expansions become necessary.
The first subsystem consists of a network of perforated PVC pipes which distribute the effluent over a forested area through an arrangement compatible with the local basin divides. It is fed by six submersible centrifugal pumps operating at moderate heads (ca. 30 m H2O). The second subsystem comprises high capacity rotating impact sprinklers fixed on hilltops covered predominantly by grasses. It is fed by two dry well centrifugal pumps operating at higher heads. The design criteria for both systems stem from a “zero runoff” legal requirement applicable within the limits of the 100 ha disposal site.
The two subsystems are compared as regards technical aspects and economics. Removal efficiencies are presented. Capital and running costs related to pumping stations, mains, distribution networks, ancillary equipment and appurtenances, power consumption, maintenance, operation, materials etc. are compared and discussed. Functions and indexes that may prove useful in feasibility studies for similar systems are presented.
The Upper James Estuary – A Study in Water Quality Management
Authors: Das K. C. 
Published: May 2018

The James River has its head waters in the Allegheny Mountains and flows generally southeasterly to Hampton Roads, Chesapeake Bay and thence to the Atlantic Ocean. Below Richmond, Virginia, the river is tidal with the channel meandering through the coastal plains. Below Hopewell it widens to a broad estuary, with a deep navigable channel bordered by tide marshes. The upper estuary, between Richmond and Hopewell, is heavily used for water supply, recreation, and industrial development.
The water entering the estuary a few miles upstream of Richmond is of good quality. However, as one reaches Richmond, the quality of the water deteriorates. There are eleven major discharging municipalities and industries within a stretch of twenty two river miles between Richmond and Hopewell. The major factors contributing to water quality problems below the City of Richmond stem from the intermittent discharge from combined sewer overflows (CSOs) coupled with the continuous discharge from the City's sewage treatment plant. The CSOs contribute a large quantity of soluble BOD, suspended solids, settleable solids, and fecal coliforms to the estuary. The City's sewage treatment plant continuously discharges large quantities of ammonia-nitrogen and phosphorus, in addition to BOD and suspended solids.
Rational Management and use of the waters of the upper James estuary appear to be critical. The objectives of this paper, therefore, are the discussion of the present water quality and the wastewater discharge reductions required in order to meet certain water quality and water use objectives.