bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sludge and washwater management strategies for the Vaalkop water treatment plant
Authors: Haarhoff J. , van Heerden P. , van der Walt M. 
Published: May 2018

The Vaalkop plant, owned and operated by Magalies Water, provides a valuable South African case study of sludge and washwater management at a large water treatment plant. Starting out as a small plant of 18 Ml/day about thirty years ago, it has steadily grown to a plant with treatment capacity of 210 Ml/day; fairly large by South African standards. During the preceding years, it has not only been subject to a vastly larger scale of operation, but it also had to adapt to a tremendous increase in the cost of raw water, an increased environmental awareness amongst water treatment professionals and general public alike, and a much more sophisticated and complicated legislative framework. It is the objective of this paper to track the sludge and washwater management practices adopted over the years at Vaalkop, and to present the current strategies adopted for the medium to long term.
The paper will summarize the previous methods of sludge and washwater disposal, with reasons why they were adopted. The multitude of technical analyses and alternatives that were performed over the years will be summarized, and may provide valuable pointers for other applications in South Africa. The current system, which has just been commissioned, will be presented; its technical design parameters, the anticipated mode of operation, its costs and how the current environmental and legislative requirements are being met.
Establishing river basin organisations in Vietnam: Red River, Dong Nai River and Lower Mekong Delta
Authors: Taylor P. , Wright G. 
Published: May 2018

River basin management is receiving considerable attention at present. Part of the debate, now occurring worldwide, concerns the nature of the organisations that are required to manage river basins successfully, and whether special-purpose river basin organisations (RBOs) are always necessary and in what circumstance they are likely to (i) add to the management of the water resources and (ii) be successful. The development of river basin management requires a number of important elements to be developed to a point where the river basin can be managed successfully. These include the relevant laws, the public and non-government institutions, the technical capabilities of the people, the understanding and motivation of people, and the technical capacity and systems, including information.
A river basin organisation (or RBO) is taken to mean a special-purpose organisation charged with some part of the management of the water resources of a particular river basin. Generally speaking, such organisations are responsible for various functions related to the supply, distribution, protection and allocation of water, and their boundaries follow the watershed of the river in question. However, the same functions can be carried out by various organisations, which are not configured on the geographical boundaries of a river basin.
This paper outlines recent work on river basin organisation in Vietnam, and makes some comparisons with the situation in Australia.
UV disinfection for reuse applications in North America
Authors: Sakamoto G. , Schwartzel D. , Tomowich D. 
Published: May 2018

In an effort to conserve and protect limited water resources, the States of Florida and California have actively promoted wastewater reclamation and have implemented comprehensive regulations covering a range of reuse applications. Florida has a semi-tropical climate with heavy summer rains that are lost due to run off and evaporation. Much of California is arid and suffers periodic droughts, low annual rainfall and depleted ground water supplies. The high population density combined with heavy irrigation demands has depleted ground water supplies resulting in salt-water intrusion. During the past decade, Florida reuse sites have increased dramatically from 118 to 444 plants representing a total flow capacity of 826 MGD. California presently has over 250 plants producing 1 BGD with a projected increase of 160 sites over the next 20 years.
To prevent the transmission of waterborne diseases, disinfection of reclaimed water is controlled by stringent regulations. Many states regulate wastewater treatment processes, nutrient removal, final effluent quality and disinfection criteria based upon the specific reuse application. As a rule, the resulting effluents have low turbidity and suspended solids. For such effluents, UV technology can economically achieve the most stringent disinfection targets that are required by the States of California and Florida for restricted and unrestricted reuse.
This paper compares UV disinfection for wastewater reuse sites in California and Florida and discusses the effect of effluent quality on UV disinfection.
Planning of wastewater treatment and disposal systems of Istanbul metropolitan area
Authors: Eroglu V. , Sarikaya H. Z. , Aydin A. F. 
Published: May 2018

Current and future wastewater treatment and disposal strategies of Istanbul city are presented. Istanbul is the largest city of Turkey and has a population of 10 million that may reach about 20 million in 2032. The city is divided into Asian and European sides by the Bosphorus Strait. The Sea of Marmara is an enclosed sea, connected to the Black Sea and Aegean Sea by the straits of Bosphorus and Dardanelles. Therefore, there is very strong and permanent stratification in the Sea of Marmara throughout the year, lower layers carrying Mediterranean and the upper layers carrying Black Sea water. This unique coastal structure of Istanbul necessitated a detailed study to determine the level of wastewater treatment and the location and depth of marine outfalls.
A comprehensive three-dimensional water quality modelling study concluded that tertiary treatment including nitrogen and phosphorus removal is required for the effluent discharges into the Marmara Sea. However, enhanced primary or even primary treatment has been found satisfactory for discharges into the lower layers of the Bosphorus and into the Black Sea. Provisions for upgrading to secondary treatment were recommended. The status of existing and planned wastewater treatment plants and sea outfalls of Istanbul city are also presented. Although the amount of treated wastewater was only 63 percent in 1998, a target of 95 percent treatment level by the end of 2000 has been adopted in implementation plans. All treatment plants are located at or close to the coast except Pasakoy WWTP which is in the catchment area of Omerli Reservoir, the major source of drinking water for Istanbul city. The Pasakoy WWTP has been designed to treat wastewaters collected from the catchment area of Omerli Reservoir to tertiary level before ultimate disposal. The implementation programme together with the cost estimates are given. Total investment on water, wastewater and stormwater projects up to year 2032 is estimated at about 10 billion US Dollars. The share of the wastewater projects in this total is increasing with time. The financial analysis concluded that investments for a Higher Demand Scenario can be realised by raising the water tariffs to 1.0 $/m3 for Phase 1 and 0.9 $/m3 for Phase 2.
Evaluation of phosphorus retention in a South Florida treatment wetland
Authors: Nungesser M.K. , Chimney M.J. 
Published: May 2018

The Everglades Construction Project of the South Florida Water Management District (District) will employ large constructed wetlands known as Stormwater Treatment Areas (STAs) to reduce phosphorus concentrations in runoff entering the Everglades. The District built and operated a prototype STA, the 1,545 ha Everglades Nutrient Removal Project (ENRP), to determine the efficacy of subtropical wetlands for improving regional water quality with a focus on reducing total phosphorus (TP). In five years of operation, the ENRP has consistently exceeded its performance goals of TP outflow concentrations &lt;50 μg P/L and a 75% TP load reduction.
Since August 1994, the ENRP has retained 70.3 metric tons of TP that otherwise would have entered the Everglades. When corrected for surface area and inflow TP load, TP removal efficiency was highest in the inflow buffer cell and decreased generally in a downstream fashion through the wetland. High TP removal efficiency in treatment cell 4 was attributed to superior performance of its submerged aquatic vegetation community relative to the emergent and floating macrophyte community in the other cells. Controlled experiments in the District's STA Optimization Research Program will help clarify what effect vegetation and operational conditions may have on nutrient removal in the STAs.
High salinity wastewater treatment using yeast and bacterial membrane bioreactors
Authors: Dan N.P. , Visvanathan C. , Polprasert C. , Ben Aim R. 
Published: May 2018

Two laboratory-scale membrane bioreactor systems were investigated to treat high salinity wastewater containing high organic (5,000 mg/L COD) and salt content (32 g/L NaCl), namely: (1) the Yeast Membrane Bioreactor (YMBR) and; (2) Yeast pretreatment followed by Bacterial Membrane Bioreactor (BMBR). In the YMBR system, experimental runs were conducted with a mean biomass concentration of 12 g MLSS/L. Here the maximum COD removal rate of 0.93 g COD/g MLSS.day was obtained at F/M of 1.5 g COD /g MLSS.d. Whereas, the BMBR system was operated with a biomass concentration of up to 25 g MLSS/L, resulting in maximum COD removal rate of 0.32 kg COD /kg MLSS.day at F/M ratio of 0.4. In comparison to BMBR, YMBR could obtain higher COD removal rate at higher organic loading, indicating the potential of a yeast reactor system to treat high salinity wastewater containing high organic concentration.
Transmembrane pressure in BMBR was progressively increased from 2 to 60 kPa after 12 d, 6 d and 2 d at a hydraulic retention time (HRT) of 14 h, 9 h and 4 h, with average biomass concentration of 6.1, 15 and 20 g MLSS/L, respectively. Whereas the transmembrane pressure in YMBR has increased from 2 to 60 kPa only after 76 days of operation, with an average biomass concentration of 12 MLSS/L and an operating HRT range of 5-32 h.
Investing in river health
Authors: Bennett J. 
Published: May 2018

Rivers provide society with numerous returns. These relate to both the passive and extractive uses of the resources embodied in river environments. Some returns are manifest in the form of financial gains whilst others are non-monetary. For instance, rivers are a source of monetary income for those who harvest their fish. The water flowing in rivers is extracted for drinking and to water crops and livestock that in turn yield monetary profits. However, rivers are also the source of non-monetary values arising from biological diversity. People who use them for recreation (picnicking, swimming, boating) also receive non-monetary returns. The use of rivers to yield these returns has had negative consequences. With extraction for financial return has come diminished water quantity and quality. The result has been a diminished capacity of rivers to yield (non-extractive) environmental returns and to continue to provide extractive values.
A river is like any other asset. With use, the value of an asset depreciates because its productivity declines. In order to maintain the productive capacity of their assets, managers put aside from their profits depreciation reserves that can be invested in the repair or replacement of those assets. Society now faces a situation in which its river assets have depreciated in terms of their capacity to provide monetary and non-monetary returns. An investment in river “repair” is required. But, investment means that society gives up something now in order to achieve some benefit in the future. Society thus has to grapple with the choice between investing in river health and other investments - such as in hospitals, schools, defence etc. - as well as between investing in river health and current consumption - such as on clothes, food, cars etc. A commonly used aid for investment decision making in the public sector is benefit cost analysis. However, its usefulness in tackling the river investment problem is restricted because it requires all benefits and costs to be measured in dollar terms, and many of the benefits arising from investments in river health are non-monetary.
In this paper, techniques that enable non-monetary values to be estimated in dollar terms are described. Applications of the techniques to the estimation of the environmental values of rivers are demonstrated. The values estimated are used to demonstrate the extent of returns that are possible from investing in river health.
Community data - where does the value lie? Assessing confidence limits of community collected water quality data
Authors: Nicholson E. , Ryan J. , Hodgkins D. 
Published: May 2018

Waterwatch is a national community-based monitoring network that aims to involve community groups and individuals in the protection and management of waterways. Waterwatch Victoria has the dual objectives of catchment education and water quality monitoring. The educational outcomes are evident, with the Waterwatch programme facilitating over 9,000 students to monitor more than 2,000 sites in waterways in 2000. This paper aims to assess the scientific value of community-collected data, through examining differences between Waterwatch data and professionally collected data. The study looked at all aspects of volunteer data collection, including data confidence protocols, equipment, and data analysis. All professional data was collated by the Victorian Water Quality Monitoring Network (VWQMN). The parameters examined in this study were turbidity, electrical conductivity (EC), pH and total phosphorus.
The level of agreement between community-collected data and professional data varied temporally and spatially. Waterwatch data for EC and pH appeared to be very similar to professionally collected data. Equipment used by Waterwatch volunteers for turbidity and total phosphorus appeared to be limited in accuracy to moderate ranges. Overall the VWQMN professionally collected data showed less variance, suggesting greater variability, potentially due to inaccuracies, in volunteer collected data.
Early warning-system for operation-failures in biological stages of WWTPs by on-line image analysis
Authors: Heine W. , Sekoulov I. , Burkhardt H. , Bergen L. , Behrendt J. 
Published: May 2018

By the observation and evaluation of the microscopic picture of activated sludge samples it is possible to introduce another biological parameter additional to conventional physico-chemical parameters for the control of biological stages of waste water treatment plants. Considering the fact that parameters like floc size and floc size distribution, structure of the flocs (compact/open), shape of the flocs (round/irregular) allow perceptions of the adjusted operation conditions of the biological stages, evidence for changing operation conditions or threatening operation disturbances can be recognised. This recognition takes place at a very early phase, because the morphology of activated sludge flocs reacts very fast to changing conditions. An automatic image analysis of activated sludge floc pictures would enable the introduction of a new sum parameter to enhance operation control of aeration tanks. By a statistical evaluation of the processed sludge images several parameters can be used to describe the alteration of activated sludge flocs characteristics.
With these biological parameters it is possible to detect altered operation conditions or threatening or existing operation problems at an early phase. Thus it is possible to plan suitable countermeasures. Furthermore, the microscopic picture is the only parameter, that gives important information about the structure of the activated sludge flocs and the biozenosis. In comparison with the mainly used physico-chemical parameters, that just give information about the inlet and outlet of the wastewater treatment plants, the microscopic picture is the only parameter that gives information about the biology of the wastewater treatment process. By means of this biological parameter an improved control and regulation of the biological stages of wastewater treatment plants can be obtained.
Comparison of combined and separated biological aerated filter (BAF) performance for pre-denitrification/ nitrification of municipal wastewater
Authors: Rother E. , Cornel P. , Ante A. , Kleinert P. , Brambach R. 
Published: May 2018

The performance of two systems of semi-industrial up-flow biological aerated filters (BAF) with pre-denitrification followed by nitrification was studied and compared under various operating and loading conditions. The first system consisted of two separate reactors for the denitrification and the nitrification step, whereas in the second system the aerobic nitrification zone was packed on top of the anoxic denitrification zone in one reactor. The second system potentially offers substantial savings in investment costs and space requirements for a large scale treatment plant.
Regarding the elimination of carbonaceous pollution and denitrification the systems did not show significant differences. However, nitrification in the combined system suffered from the mixing of different biocenosis by daily backwashing and was reduced to 50-70% of the separated system's performance. Factors such as oxygen concentration, raw water composition and loading rates affected both systems' nitrification rates in similar ways. Since it is impossible to optimise the nitrification and denitrification processes separately, the combined system should only be considered for large scale applications if space is very scarce and if a stable raw water composition can be expected. If strict limit values for nitrate have to be met in the effluent, a combination of pre- and post-denitrification is advantageous and advisable.
Sensor system using polarization analysis method to monitor oil-on-water in water purification plants and rivers
Authors: Sanuki Y. , Hiraoka M. , Ohto T. , Kanai H. , Tada H. 
Published: May 2018

Some 80% of accidental pollution in river water is caused by oil spills. Oil spills can cause serious damage such as suspension of water intake at water purification plants and major harm to ecosystems in the lower reaches of rivers. This is because oil-on-water tends to spread easily, quickly exacerbating the damage. To address this problem, an automated, continuous sensor system with high sensitivity can be used for early detection of spill accidents.
We have developed a sensor system for detecting oil-on-water based on a polarization analysis method. Its advantages include: a) no direct contact with sample water; b) minimal maintenance; c) largely unaffected by foreign matter and waves on the water surface; and d) much higher sensitivity than simple visual observation.
This paper describes the measurement principle and configuration of the sensor system, and discusses the results of sensitivity tests and tests on the influence of water turbidity, foreign matter and waves. We will also consider some of the limitations of the new system.
Co-removal of hexavalent chromium during copper precipitation
Authors: Sun J. , Huang J.-C. 
Published: May 2018

In our recent study using the nucleated precipitation technology to treat plating wastewater, it was found that about one half of hexavalent chromium was co-removed with copper, nickel and zinc. Since hexavalent chromium could not react with either hydroxide or carbonate to from precipitates, this study was undertaken to evaluate the mechanism(s) involved in the chromium co-removal.
Batch tests were conducted with synthetic solutions containing either only copper or both copper and hexavalent chromium. Metal precipitation was induced by adding Na2CO3 to different pH, and the quantitative removal of copper and chromium was determined. Besides, the [Cr]/[Cu] molar ratio of produced precipitates were also assessed in conjunction with the EDAX analysis to determine their compositions. Experimental results indicate that for pure copper solution, precipitation begins at pH 6.0, and completes at pH 7.0. The chemical forms of the precipitates are copper carbonates [CuCO3.Cu(OH)2 and CuCO3.2Cu(OH)2]. On the other hand, in a bi-metal solution of copper plus chromium, precipitation of copper begins at about pH 5.0, and copper precipitation is always accompanied by some chromium removal. From the removal stoichiometry of the two metals, it is found that at low pH, the co-removal is a result of “co-precipitation” which results in the formation of CuCrO4 crystallites. Once such crystallites are formed, they provide a heterogeneous environment which enhances an early formation of copper carbonate at a lower pH (below 5.5). It is further found that once copper carbonate precipitates are produced, the remaining soluble will precipitate in such form, and at this stage further removal of copper is no longer accompanied by additional chromium removal. The test data also reflect that the produced copper carbonates are positively charged, as verified by zeta potential measurement, at pH below 7.5. Thus they are able to adsorb some anionic chromium (existing as chromate) through electrostatic attraction and/or inorganic ligand exchange. At pH of 6 to 10, the extent of adsorption decreases with increasing pH, and the adsorption capacity seems to coincide with the progressive reduction of positive zeta potentials of the precipitated particles.
Wastewater reclamation for use in snow-making within an alpine resort in Australia - resource rather than waste
Authors: Tonkovic Z. , Jeffcoat S. 
Published: May 2018

The Mt Buller Alpine Resort is located approximately 200 km north of Melbourne, in Victoria, Australia. A wastewater treatment plant services the resort and currently treats to advanced nutrient removal standards. The treated effluent is presently discharged into the Howqua River.
Most Australian ski resorts are not blessed with abundant snow cover on a regular basis. Artificial snow allows most of the popular ski runs to operate for the whole of the season. At the Mt Buller resort, snow-making is presently limited by lack of water supply in the catchment. The conditions at Mt Buller resort present a unique opportunity to utilise reclaimed wastewater to allow increased snow-making capacity. It is one of the unique opportunities where the wastewater is valued as a resource rather than merely viewed as a waste problem.
Wastewater reclamation for snow-making will require additional treatment for pathogen removal. It is proposed that following advanced nutrient removal, the effluent will require further treatment, including membrane ultrafiltration, so as to ensure a minimum of four barriers for pathogen removal.
Pilot plant operation of a membrane ultrafiltration system commenced in June 2000 and will continue until the end of 2001, to primarily demonstrate the extent of pathogen removal.