bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wastewater treatment and reuse for aquaculture
Authors: El-Gohary F. , El-Hawarry S. , Badr S. , Rashed Y. 
Published: May 2018

A continuous laboratory scale model, simulating an oxidation pond system has been used to investigate the treatability of municipal wastewater and to evaluate the treated effluent for aquaculture. While the detention period was kept constant at 25 days, the organic loading rate fed to the system changed with changes in the BOD5 of the raw sewage and varied from 15.7 to 58.3 with an average value of 34.1 kg BOD5/ha/day.
Monitoring of the system indicated remarkable improvement in the water quality of the treated effluent. BOD5 was around 26 mg O2/l. Average residual values of COD, suspended solids and phosphorus were 154, 65 and 3.2 mg/l respectively. A reduction up to 99.99% in coliform bacteria population has been recorded. However, residual values were still high.
Tilapia fish grew healthily during the study period. Daily growth rate was 1.43% of the body mass. The productivity was 7.15 kg/ha/day. The corresponding extrapolated yield was 26.09 t/ha/yr which is considered to be a high yield as compared to published information.
Biological removal of algae in an integrated pond system
Authors: Meiring P. G. J. , Oellermann R. A. 
Published: May 2018

A system of oxidation ponds in series with a biological trickling filter is described. It was known that this arrangement was incapable of reducing effectively the levels of algae present in the pond liquid even though nitrification was effected because of autotrophic conditions prevailing in the trickling filters. This very low trophic level explained the lack of adsorptive capacity present.
By shortcircuiting less than 10 percent of the effluent from a fully loaded primary facultative oxidation pond to the trickling filter, the autotrophuc nature or the film in the trickling filter was sufficiently shifted towards a heterotrophic state that had sufficient adsorptive capacity to retain the majority of the algae.
It is concluded that the algae, although being absorbed, stay alive on the film and do not contribute significantly to the carbonaceous load on the trickling filter. Further more the algae, although secluded from all sunlight, actually partake in the purification process, producing an effluent which, unlike a normal humus tank effluent, is surprisingly sparkling clear. This significant observation appears to be in line with laboratory findings by others who, when they artificially immobilised certain species of algae and passed water over them, concluded that the algae retained the potential to remove certain compounds from the water. Conglomerates of biologically flocculated dark-green algae are scoured off the film (or sloughed off as part of the film) and, having been photosynthetically inactive for some days, tend not to float, but settle very rapidly.
A very significantly aspect of this development is the great potential it has for practical application in developing countries. The algae sloughed off the media are easily thickened and available for ultimate recovery from the water phase without the addition of chemicals.
Occurrence of Giardia sp. cysts during a wastewater treatment by a stabilization pond in the South of France
Authors: Wiandt S. , Baleux B. , Casellas C. , Bontoux J. 
Published: May 2018

This study was conducted to determine Giardia sp. cysts concentration in wastewater influents and effluents of a stabilization pond system located in Mèze (03°35′06″E, 43°25′10″N), South of France.
In raw sewage mean concentrations ranging from 0.23-25.103 cysts 1-1 were found from February 92 to July 93.
Prior to November 92, large volume filtration combined with brightfield microscopy served as the method for cyst recovery and detection in pond effluents. From November 92, the detection of Giardia sp. cysts was performed by an indirect immunofluorescent antibody test.
No cysts could be detected in the final effluents during summer 92 by brightfield microscopy, whereas cysts were recovered in effluents from the first basin. Cysts were detected in final effluents during wintertime by the fluorescent antibody-technique (0.1 to 2.5 cysts 1-1). However, no cysts were detected during spring/summer 93 in final effluents.
We conclude that alum coagulation in conjunction with immunofluorescent antibody techniques for the concentration and detection of Giardia sp. in stabilization pond effluents increases the recovery efficiency and identification of waterborne cysts.
The results of this study indicate a good removal efficiency of cysts in a stabilization pond during spring/summertime but a potential risk of cyst discharge during wintertime.
Quo vadis - sustainability?
Authors: Tyson J. M. 
Published: May 2018

There is a developing concern that the world water resource will prove to be inadequate to meet the ever-increasing demands by humankind. An integrated river basin management approach is essential for land and water use planning due to the complexity of land/water interactions.
This paper provides a selective overview of some of the issues affecting sustainability in river basin management. These include the need to: develop methodologies for integrated river basin management which include land-use management and planning; improve the volume and accuracy of national and global assessment of water resources; develop, promulgate and implement waste minimisation and recovery techniques, preferably pollution prevention; develop low-tech, low cost treatment options; increase application of use-related receiving water standards; develop and apply economic evaluation tools to both environmental costs and benefits; and inform, educate and train professionals and the public.
Any solution arrived at must be acceptable to the local community; two-way communication is vital to the success of a project, which may well require changes in the behaviour of the community served.
Integrated catchment management: is it wishful thinking or can it succeed?
Authors: van Zyl F. C. 
Published: May 2018

The need for better and improved water resources management has been echoed time and again worldwide. In South Africa, where water has been identified as a scarce resource and a limiting factor for development, the situation is even more critical. To address this problem, management of water on an integrated catchment basis has been applied to various catchments in the country. The development and implementation of this approach offered managers unique learning experiences. They had to content with complex water resource problems as well as with economic and political difficulties. On the one hand it was a very exciting and challenging experience, on the other hand success was limited and in many cases the results were disappointing.
In this paper, the approaches adopted and the experiences gained in the execution of more than twenty major catchment management projects, as well as various issues impacting on the outcome of the projects, are highlighted. It is important to realise that this approachs is in a development phase and still requires time and energy to become a meaningful management practice.
Management of microbial water quality: new perspectives for developing areas
Authors: Steynberg M. C. , Venter S. N. , de Wet C. M. E. , du Plessis G. , Holhs D. , Rodda N. , Kfir R. 
Published: May 2018

A case study indicated that the high number of pathogenic micro-organisms in the Rietspruit, South Africa, can impact water uses. Factors contributing to high microbial numbers are high density population with limited services provided per site, sabotage of the sewage reticulation system, lack of money and management skills to provide the essential services and limited integrated development planning for the catchment.
Due to non-steady state conditions in the catchment, the specific use and physical characteristics of the river and the difficulty in determining flow, the usefulness of a steady-state stream water quality model as a management tool is limited. Determining the decay rate of micro-organisms by means of chamber studies, may be a first step to predict microbial water quality. Involving the community in preventing microbial pollution may be a more appropriate tool for microbial water quality management in developing areas.
Effluent re-use in a tourist resort - larnaca sewage treatment and irrigation project - cyprus
Authors: Mill G. A. , Theophilou J. A. 
Published: May 2018

Designs for sewerage, sewage treatment and effluent disposal prepared in the 1980's, included for marine disposal of secondary treated and disinfected effluent via a 1.5 km long sea outfall. A reappraisal of the scheme in 1990 reviewed alternative options with a view to reducing costs and utilising effluent.
An economic comparison showed that effluent storage and irrigation was an attractive alternative to marine disposal.
A scheme was designed whereby all effluent will be given secondary treatment, stored in reservoirs until required for irrigation, withdrawn through sand filters, disinfected and pumped to an irrigation distribution system serving public amenity areas throughout Larnaca, including parks, gardens, road verges and hotel areas. A sea outfall will not be provided.
The advantages of the scheme are conservation of water, improvement to the environment and prevention of marine pollution at a reduction in cost compared to the originally proposed scheme.
Denitrification kinetics in an activated sludge system
Authors: Roš M. 
Published: May 2018

For all water bodies especially for sea, lakes, and ground waters it is very important that nutrient pollution is the least possible (minimal). From municipal and industrial waste waters where considerable amount of nutrients is expected it is possible to remove nutrients with biological treatment. The first step is usually aerobic activated sludge treatment and the second step is combined anaerobic-anoxic-aerobic step in different combinations. A very effective process for nitrogen removal is anoxic activated sludge system. It is very important that in the first aerobic step complete nitrification is achieved.
In our laboratory denitrification kinetics was studied. The objective of this study was determination of denitrification velocity and attendance of different parallel phenomena such as nitrite, disappearance of nitrate and nitrite, sulphide formation, etc.
Denitrification process was studied in two systems, in closed system (such as in closed reactors for denitrification) and in open systems (such as in open denitrification tanks). We found out that denitrification rate in closed systems was from about 8 to 52 mg/l.h and was dependent on activated sludge type, sludge concentration, and temperature of the system. In open system (such as in an anoxic aeration tank) the rate of denitrification was lower than in closed system; it was from 4 to 15 mg/l.h dependent on activated sludge type, sludge concentration, and temperature of the system. Experiments were carried out in the range of temperature from 20° to 30°C.
Achieving reliable and cost effective water treatment
Authors: Egerton Amanda-Jane 
Published: May 2018

There is increasing pressure from financial and quality regulators both to reduce costs and to improve levels of service within the water industry. It is possible to reduce costs to some extent without affecting levels of service unduly. However, there comes a time when further reductions have a major impact on the reliability of the treatment process and the reductions are no longer cost-effective.
On examination, it is typical to find that the overall risk of treatment failure is dominated by a small number of significant problem areas or pinch-points within a system. Removal of these pinch-points through design or operational changes will lead to improvements in levels of service. Alternatively, if the pinch-points dominate the risk and cannot be removed cost-effectively, there is little point in over-protecting other areas through the inclusion of standby equipment or with unjustified levels of maintenance. Thus costs in these areas can be cut back without unduly increasing the overall risk of failure.
This paper shows how risk analysis can be used to identify those areas of a system that dominate its risk of failure. This allows its design and operation to be optimised, thereby enabling levels of service to be met at minimum cost.
15 years of practical sewage treatment in Venezuela
Authors: Lansdell M. 
Published: May 2018

A summary of fifteen years of experience of the design, operation and performance several Venezuelan municipal wastewater treatment systems to serve a population of 5 million is presented.
Technical and institutional problems which occurred during construction and operation are described and some of the solutions are presented. It was found that the most simple systems were the most effective and that it was important to develop solutions appropriate to local needs and avoid the technological dependance on imported spare parts.
Domestic sewage treatment in an upflow anaerobic sludge blanket - sequencing batch reactor system
Authors: de Sousa J. T. , Foresti E. 
Published: May 2018

Domestic sewage treatment in up-flow anaerobic sludge blanket (UASB) reactors has presented significant results in tropical regions. This reactor configuration has proven to be efficient in removing organic matter and total suspended solids as well as in producing smaller amounts of excess sludge than conventional aerobic reactor. On the other hand, its effluent often requires to be post-treated in order to achieve the emission standards.
This paper is concerned with the alternative proposed here for treating domestic sewage in a combined anaerobic-aerobic system composed of an UASB reactor followed by sequencing batch aerobic reactors (SBR). In such a system, the UASB reactor removes considerable fraction of the influent organic matter, while the SBRs oxidize part of the remaining organic matter and ammonium nitrogen. A proper system operation would also permit the removal of nutrients (N and P).
In order to investigate on the performance of this system for sewage treatment, a bench scale installation fed with synthetic substrate simulating domestic sewage was operated continuously during 38 weeks. The results permit to confirm the hypothesis proposed, since the system has consistently produced high quality effluents (BOD5 and VSS lower than 10 mg.L-1).
The results also indicate that such combined anaerobic-aerobic system compete favorably with conventional aerobic systems in three essential cost features: energy consumption, excess sludge production and nutrient removal.
Policy options for environmentally sound technology in India
Authors: Khanna P. 
Published: May 2018

The emergence of the concept of sustainable development in recent years has brought in the general realisation that societal perceptions must shift towards ecological determinism so as to achieve qualitative growth within the limits of the ecosystem's carrying capacity. The carrying capacity based planning process, innovative technologies for enhanced material and energy effectivity of production and consumption, structural economic change towards less resource-intensive sectors, and preventive environmental management through increasingly interventionist policies are some of the strategies for reconciling developmental goals with ecological capabilities.
The paper analyzes existing and future environmental issues emanating from developmental objectives and policies in population, agriculture and forestry, energy, industry and human settlement sectors in India and suggests an agenda for action, with focus on environmentally sound technology, to ensure discernible positive movement towards the overall aspirational goal of sustainable development.
It argues for a dynamic policy framework for environmental management in which the time lag between problem awareness, technological solution and remedial action is minimized through anticipation and prevention of environmental problems that may arise as a consequence of decisions taken within various sectors of the economy; restoration of environmental quality wherever necessary; structural changes in the economy; and inter-policy coordination.
Finite element digital model for longitudinal dispersion of pollutant in porous media
Authors: Rao K. Srinivasa 
Published: May 2018

Surface and groundwater sources of water are being contaminated in the course of rapid urbanization and industrialization. The groundwater environment is being assaulted with an ever increasing number of soluble chemicals and human and industrial wastes which are let out on to the surface without treatment. Groundwater pollution often results in aquifers being damaged beyond repair. To prevent the pollution of groundwater resources, first we should identify the areas and mechanisms by which the pollutants enter the groundwater systems and the development of reliable predictions of the transport of the contaminant within the flow systems. These predictions will become the basis for minimizing the impact of existing or proposed industrial, agricultural and municipal activities which may affect the groundwater quality.
It is necessary to study the different engineering aspects of groundwater quality control. The different aspects include 1) anticipating the probable future solute concentration distribution in the groundwater aquifer at any time since the beginning of the contamination and 2) deciding whether the contamination of a particular groundwater zone has crossed the limits of tolerance. From the above points, it is strongly felt that there is need to study the phenomenon of dispersion of pollutant in the porous media flow.
The study necessitates the solution of a differential equation describing the solute transport process. In this study, a finite element digital model has been developed for longitudinal dispersion of the pollutant in the porous media. The results obtained from the above model are found to be in close agreement with those of the analytical solution given by earlier researchers.
Near bed solids transport in sewers
Authors: Arthur Scott , Ashley Richard M. , Nalluri Chandramouli 
Published: May 2018

This paper describes the results of three sewer sediment studies, carried out in Dundee, financed by the Engineering and Physical Sciences Research Council (EPSRC) and the Water Research centre (WRc). The work was carried out by the University of Abertay Dundee (Wastewater Technology Centre) as part of a collaborative research project undertaken with the University of Newcastle and the University of Sheffield.
In Dundee, through collaboration with the sewerage system operator (Tayside Regional Council Water Services Department), three field sites have been established in interceptor and trunk sewer sites, since 1992, to monitor, as closely as possible, sediment and other pollutant erosion, their transport and the effects of first flushes.
The physical and biochemical nature of the material being transported near the bed of real sewers has been measured. The importance of this mode of transport, in terms of mass transported and pollutant potential, is demonstrated based on data collected from the Dundee system sites. Comparisons are made between measured transport rates at the bed, at sites with and without deposited beds, with results obtained by applying empirical relationships developed to predict near bed transport in laboratory studies. A modified relationship is proposed which best fits the Dundee system data.
Suspended solids in combined sewer flows
Authors: Gupta Kapil , Saul Adrian J. 
Published: May 2018

Many studies have identified the first flush phenomenon as being the relatively high concentration of pollutants in the initial phases of combined sewer flow following a storm. One way of controlling the first flush is by the provision of a storage tank such that the effluent can be discharged in a controlled manner. To optimise the storage volume, both the total pollutant load discharged and the temporal variation in pollutant concentration within an event need to be predicted. Sophisticated models to predict the pollutant concentrations in urban sewer flows, for example QSIM and MOUSETRAP are already available. However, the data requirements for these models are extensive, which usually limit their application to major or environmentally sensitive schemes.
This paper describes attempts to relate the peak concentration of suspended solids in combined sewer flows to observed storm characteristics. In this study, it was hypothesised that the peak concentrations of suspended solids could be related to the hydrological parameters of maximum rainfall intensity, storm duration, and antecedent dry weather period prior to the storm which are commonly used as the basic parameters for urban sewer design. Data from two sites at Great Harwood and Clayton-le-Moors in the North-west of England has been used in the study and an attempt has been made to define an upper limit of the first flush concentration of suspended solids corresponding to storms which have been categorised into bands defined by their peak rainfall intensity.
Characterization of immobilized cells in biodegradation of ABS resin manufacturing waste-water
Authors: Wen-Chin Chen , Sheng-Shung Cheng 
Published: May 2018

Because of the presence of refractory and biologically inhibitory organic compounds in ABS resin wastewater, which would retard the bioactivity of the autotrophic nitrifier and make the efficiency of nitrification process unstable, the application of cell immobilization for ABS wastewater treatment has been investigated by immobilizing the enrichment culture of nitrifying bacteria with alginate. The characterization of the immobilized cells in various alignate concentrations was conducted by a series of biodegradability studies with electrolytic respirometry and compared with the differences from the dispersed cells.
Results clearly indicated that immobilized cells achieved higher efficiency of COD and TKN removal than that of the dispersed cells during the period of high initial concentration of wastewater. Meanwhile, high concentration of cells were growing near the gel surface and reduced the effects of diffusional restriction. No remarkable difference was found while the concentration of alginate ranged from 3% to 5%. According to mass balance of total nitrogen, more than 25% of total nitrogen was removed in the batch system of the immobilized cell. Simultaneous nitrification and denitrification could occur due to the oxygen gradient throughout the gel matrix. Compared with the complete mixing system of the dispersed cell, the approach for the immobilized-cell system provided a more effective method for treating the special wastewater with high strength of nitrogenous and inhibitory compounds.
Strategies and management models for metropolitan wastewater, implementation and evaluation in the East Rand, South Africa
Authors: Korf A. W. , Wilken J. W. , Nel N. J. 
Published: May 2018

South Africa is a country where first world wastewater treatment technology and management must take into account third world related problems. In the past, the diversity of a large number of local authorities within the PWV area of South Africa aggravated the problem of proper wastewater management.
On the East Rand in the Gauteng province of South Africa, the problem was attended to by means of a strategic analysis and strategic plan. In the evaluation of the options, the various wastewater management models in use in various regions of the world were evaluated. The investigation resulted in the formation of the ERWAT wastewater management model and implementation.
The paper also evaluates the success of the wastewater management model utilizing the tariff model and other qualitative parameters.