bluuebunny/crossref_metadata_2025_split huggingface dataset:
An attempt to understand dissolved air flotation using multivariate data analysis
Authors: Krofta Milos , Herath Banda , Burgess David , Lampman Larry 
Published: May 2018

In order to optimize the dissolved air flotation (DAF) process, a mathematical relationship should be established between the operating variables and the quality of the effluent water. In this study, operating parameters, including influent wastewater characteristics, were related to suspended solid (SS), COD, BOD5 and turbidity of the effluent via an empirical mathematical model.
The data presented in this study were obtained from a pilot plant DAF study carried out on municipal wastewater at Lee, Massachusetts to determine the operating conditions for the wastewater clarification. Response surface methodology was used to determine optimal conditions and to study the variations of flotation behaviour with varying operating conditions.
The multivariate technique used in this study is an extremely valuable tool to analyze data obtained from actual wastewater treatment processes where the characteristics of the wastewater are constantly changing. Without such a tool it may not be possible to draw valid conclusions. In addition, this technique requires comparatively fewer experiments when compared to traditional methods.
Addition of more flocculant and recycle water over what is required actually decreases the effluent water quality. Tests carried out with the same DAF unit at Little Rock, Arkansas and Birmingham, Alabama have confirmed the accuracy of the predictions from the model.
The relationship between health effects in triathletes and microbiological quality of freshwater
Authors: Medema G. J. , van Asperen I. A. , Klokman-Houweling J. M. , Nooitgedagt A. , van de Laar M. J. W. , Havelaar A. H. 
Published: May 2018

This pilot study was carried out to determine the relationship between microbiological water quality parameters and the occurrence of health complaints among triathletes. Data were collected at an Olympic distance triathlon (n=314) and a run-bike-run (n=81; controls for exposure to fresh water). At the time of the triathlon, the concentrations of Escherichia coli , thermotolerant coliforms, faecal streptococci, entero- and reoviruses, F-specific RNA phages, Salmonella, Campylobacter, Aeromonas, Plesiomonas shigelloides, Pseudomonas aeruginosa and Staphylococcus aureus were examined over the swimming course. Information on the occurrence of health complaints during the competition and in the week thereafter was collected through a written questionnaire.
The results show that triathletes and run-bike-runners are comparable with respect to factors other than water exposure (age, sex, training history, physical stress, lower intestinal health complaints during the competition) that may influence the occurrence of health complaints in the week after the competition.
Triathletes and run-bike-runners reported gastro-intestinal (7.7% vs 2.5%), respiratory (5.5% vs 3.7%), skin/mucosal (2.6% vs 1.2%), general (3.5% vs 1.2%) and total symptoms (14.8% vs 7.4%) in the week after the event. The health risks for triathletes for all symptom groups are not significantly higher than for run-bike-runners. The geometric mean concentration of faecal indicator bacteria is relatively low: E. coli 170/100 ml; faecal streptococci 13/100 ml, enteroviruses were present at concentrations of 0.1/l. The group of triathletes was homogeneusly and relatively intensely exposed to water; they all swam in the same body of water at the same time and 75% reported to have swallowed freshwater.
It was concluded that this study design is suitable to study the relationship between health complaints and microbiological water quality. In the summers of 1993 and 1994, a study will be carried out concerning several run-bike-runs and triathlons in freshwaters of different quality.
Designing a research programme to promote river basin management
Authors: Breen C. M. , Biggs H. , Dent M. C. , Görgens A. , O'Keeffe J. , Rogers K. H. 
Published: May 2018

Growing perceptions that ecological research is failing to meet the needs of resource managers has prompted a review of the structure and management of research programmes.
In this paper we identify principles, frameworks and approaches to guide the restructuring of research programmes. Their application is discussed in relation to the restructured research programme on the rivers flowing through the Kruger National Park. A preliminary evaluation after one year of operation of this programme indicated beneficial changes in research and in stakeholder and client attitudes to research.
Differential accumulation and depuration of human enteric viruses by mussels
Authors: Bosch A. , Pintó R. M. , Abad F. X. 
Published: May 2018

The tissue distribution of adenovirus 40 (ADV) and human rotavirus, serotype 3 (HRV) was determined after feeding the common mussel (Mytilus spp.) with high levels of clay-associated virus. At different time intervals, individual tissues were carefully dissected and assayed for infectivity. Viruses were detected in contaminated mussels after 1-hour contact, and maximum levels were observed after 6 hours. Most infectious viruses were located in the gills and in the digestive tract. Decreasing virus numbers were found in the mantle lobes.
Mussels contaminated with poliovirus 1 (PV), hepatitis A virus, strain HM-175 (HAV), ADV, HRV, and bacteriophages of Bacteroides fragilis (B40-8) were depurated in 50-1 tanks with a continuous flow of ozonated marine water. After 96 hours, HAV and HRV suffered less than 2 Log10 titre reduction (LTR), while ADV showed a 2.7 LTR. PV showed a 3 LTR after 48 hours and became undetectable thereafter. Bacteriophage B40-8 suffered less than 2 LTR after 96 hours, suggesting that it could be an appropriate indicator of the efficiency of virus elimination during shellfish depuration.
Effects of an anaerobic zone in a textile wastewater treatment plant
Authors: Bortone G. , Cech J. S. , Bianchi R. , Tilche A. 
Published: May 2018

High concentration of textile industries represents a serious environmental problem in the Como area in Northern Italy. The Seveso treatment plant was formerly performing biological removal of nitrogen by means of a modified Ludzack-Ettinger configuration. Being the plant overloaded, nitrification was not achieved. Therefore the plant flow sheet has been modified. The former predenitrification tank has been changed in an anaerobic compartment, since the internal recycle was stopped.
The efficiency of the anaerobic reactor for COD removal, the selective pressure on the microbial community and the enhanced biological phosphorus removal were evaluated.
In the anaerobic tank 40% of the influent COD was removed with a reaction time of only 45 minutes. The activated sludge showed a very high presence of Poly-P bacteria; anaerobic P release was noticed during the anaerobic phase. Sludge settleability was always good (contrary to a similar activated sludge treatment plant, also treating textile wastewater but without an anaerobic selector, that suffers heavy filamentous bulking and Nocardia foaming). The final effluent PO4-P concentration was always lower than 1 mg L−1.
Integrated waste disposal strategy for the Orkney Islands - a case study
Authors: Chambers B. , Chapman R. E. , Cross R. T. 
Published: May 2018

The Orkney Islands are situated several miles off the north east coast of Scotland and comprise about 40 separate islands, of which about 16 have a significant number of inhabitants. The total population is about 20,000 with 7,500 living in Kirkwall, the main town.
The EU Urban Waste Water Treatment Directive (UWWTD) has presented the Orkney Islands Council with an opportunity to develop an integrated waste disposal strategy for the entire group of islands. The problems which must be overcome are common to many island communities with limited land availability and seasonal industries based on agriculture and fishing.
The waste disposal strategy developed by Orkney Islands Council provides an integrated solution to a complex problem and takes into account the shortage of available land for sludge disposal and the effect of effluent treatment costs on the economics of interdependent island industries.
The strategy involves the construction of a new sewerage system to intercept the Kirkwall outfalls and deliver the sewage to a new treatment site prior to long sea outfall discharge. The most significant industrial discharges each contain a very high proportion of soluble BOD. As a result, primary treatment alone cannot achieve the reductions is SS and BOD required by the UWWTD. Some industrial effluents will therefore be pre-treated before discharge to sewers. The sludge disposal strategy has been developed to provide sustainability and outlet security. Accordingly two disposal routes have been proposed. These are land disposal or drying and co-incineration with domestic waste in a new incineration complex. Sludge from the outlying communities will be dewatered using a mobile centrifuge before being transported to Kirkwall for ultimate disposal.
Dynamic simulation of sludge blanket movements in a full-scale rectangular sedimentation basin
Authors: Göhle F. , Finnson A. , Hultman B. 
Published: May 2018

Bromma sewage treatment plant in Stockholm is the second largest plant in Stockholm and will in the near future have requirements for nitrogen removal. This means that a higher sludge age must be used in the aeration basin. This may be accomplished by an increase of the sludge concentration up to values until the limiting solids flux is exceeded. Measurement of the sludge blanket level is a possibility for better control of the sedimentation basin. Different measurements were performed to evaluate the main factors influencing the level.
Dynamic simulation studies were performed at Bromma sewage treatment plant in Stockholm of the sludge blanket level and the return sludge concentration in a full-scale sedimentation basin. The simulations were performed with the help of a Danish simulation package, EFOR (1992), in which both reactions in the aeration basin (mainly based on the IAWPRC model) and separation processes in the sedimentation basin (both clarification and thickening) can be studied. The thickening model is based on the solids flux theory and the Vesilind formula (1979). Different methods were compared for determination and use of characteristic parameters in the Vesilind formula.
Biological nutrient removal in a sequencing batch reactor treating domestic wastewater
Authors: Bernardes R. S. , Klapwijk A. 
Published: May 2018

This investigation aims to monitor a strategy for biological nutrient removal (nitrogen and phosphorus) in a Sequencing Batch Reactor (SBR) treating domestic wastewater. For this, the performance of an SBR with nitrification, denitrification, carbon oxidation and phosphorus removal is evaluated.
During this study the influent used was pre-settled domestic wastewater from Bennekom-Municipal Treatment Plant (The Netherlands). The average influent COD, TKN and phosphate were 443 mg COD/1, 71 mg N/1 and 7 mg P/1, respectively. Acetic acid was added to this influent from a feed solution, to increase the COD by an extra 100 mg COD/1.
In this study, a pilot plant SBR was operated during 5 months in order to have: i) a mixed culture able to perform carbon oxidation, nitrification, denitrification and biological phosphorus removal and ii) long term assessment of the biological nitrogen and phosphorus removal processes. Pilot plant SBR consists of two cylindric polystyrene vessels, the first with total volume of 0.35 m3 (Reactor 1) and the second with total volume of 1.3 m3 (Reactor 2).
The effluent had, in average, phosphate concentration lower than 1 mg P/1 and nitrogen concentration lower than 12 mg N/1.
Quality improvement of biosolids by ferrate(VI) oxidation of offensive odour compounds
Authors: Chao Allen C. , de Luca Sergio J. , Idle Carlos N. 
Published: May 2018

Studies concerning the treatment, stabilization and final disposal of biosolids, one of the by-products of wastewater treatment, in environmental recovery, have been intensified by the sanitary and environmental effects of land disposal. The careful assessment of biosolid quality shows that, when appropriately managed, the environmental risks of their uses can be minimized by chemical stabilization, and biosolids could even be used as fertilizer and soil conditioner.
A research study of biosolid stabilization was performed using lime as a standard process compared to potassium ferrate (VI). The chances of leaching and solubilization of metals were tested, simulating conditions for disposal in the environment. The sanitary effectiveness in terms of pathogens (bacteria, fungi and helminth eggs) were also evaluated.
Experiments were performed on the lime and ferrate(VI) treatment of compounds such as ammonia, nitrate, soluble sulphides, and total sulphates, indicators of odouriferous offensive compounds which might occasionally prevent some uses of the solids, and the results are presented in this paper.
Wastewater Treatment Plants emit offensive odours generated during the sewage treatment process, as well as during the treatment and the management of biosolids. This occurs in the drying beds and the spreading of biosolids on land, due to the high concentrations of sulphur compounds, nitrogen compounds, acids and organic compounds (aldehydes and ketones).
The potassium ferrate(VI) utilized in the research is a powerful oxidizing agent throughout the pH scale, with the advantage of not generating by-products which will cause toxicity or mutagenicity (DE LUCA, 1981). The ion ferrate(VI) has greater oxidizing power than permanganate, e.g., it oxidizes reduced sulfur forms to sulphate, ammonia to nitrate, hypochlorite to chlorite and chlorite to chlorate(DE LUCA et al., 1992; CHAO et al., 1992).
This paper shows that, as expected, the potassium ferrate (VI) treatment replaces several chemical products utilized for odour control of sludges, mainly aggressive odours caused by ammonia and sulphides, through the formation of precipitates with iron compounds. Ferrate (VI) has often been shown to destroy soluble sulphides, transforming them into sulphate. The generation of oxygen in the decomposition of ferrate(VI) increases its oxidizing power. Ferrate(VI) applied to sludges also has the double effect of transforming ammonia into nitrates, such that this product takes the place of sulphates, acting as an electron acceptor, thus preventing the development of further odours when biosolids are utilized.
Toxicity of phenolic wastewater to luminescent bacteria photobacterium phosphoreum and activated sludges
Authors: Kahru A. , Kurvet M. , Külm I. 
Published: May 2018

Ash-heap water (AHW - phenolic wastewater of local oil-shale industry) was analyzed for its phenolic composition using HPLC and for its relative toxicity using MicrotoxTM and BiotoxTM tests where inhibition of natural luminescence of photobacteria is used as toxicity endpoint. Most abundant components in AHW were phenol (84 mg/L) and p-cresol (70 mg/L). The 5-min EC50 values for AHW (the concentration of AHW, %, which reduces the light output of bacteria by 50% after being in contact with bacteria for 5 minutes) for BiotoxTM and MicrotoxTM tests were 1.5% and 0.6%, respectively.
Also, the toxicity of AHW towards two different activated sludges (acclimatized and not acclimatized to phenolic wastewater) was evaluated using decrease of adenosine triphosphate (ATP) content of the sludge as toxicity endpoint. AHW was relatively non-toxic to activated sludges, especially to the acclimatized sludge. The respective 60-min EC50 value for AHW (the concentration of AHW, %, which decreases the ATP level of activated sludge compared to the non-exposed control by 50% after being in contact with sludge for 60 minutes) was 20-30% for non acclimatized sludge and 50-60% for acclimatized sludge. Therefore, the biopurification of AHW using an adapted activated sludge process could be considered feasible.
Study of toxicity of pesticides using luminescent bacteria Photobacterium phosphoreum
Authors: Kahru A. , Tomson K. , Pall T. , Külm I. 
Published: May 2018

The relative toxicity (expressed as 5-min EC50 value - the concentration of chemical which reduces the light output of bacteria by 50% after contact for 5 minutes) of 13 pesticides (e.g., 2,4-dichlorophenoxyacetic acid, atrazine, coumarin, glyphosate, paraquat, pentachlorophenol, lindane, malathion) and 14 solvents was evaluated using BiotoxTM test that is based on reconstituted freeze-dried viable Photobacterium phosphoreum. The most toxic of the 13 pesticides analyzed using BiotoxTM was pentachlorophenol (5-min EC50=0.55 mg/L) and the less toxic was paraquat (5-min EC50=14800 mg/L). The 5-min EC50 data for BiotoxTM were compared to the respective data for MicrotoxTM test (also based on freeze-dried P. phosphoreum) and rodent oral LD50 values. For BiotoxTMvs MicrotoxTM the log-log correlation coefficients for the whole data set (pesticides+solvents, pesticides, solvents) were 078, 0.37 and 0.95, respectively. The less toxic solvents to BiotoxTM were ethylene glycol, DMSO, methanol, ethanol, acetone and acetonitrile and, therefore, these solvents could be used for increasing the solubility of lipophilic compounds, e.g., for testing the toxicity of pesticides.
In order to analyze toxic effects of pesticides in complex mixtures the EC50 values of pentachlorophenol, coumarin and glyphosate as pure substances and in their mixtures were compared: the toxic effects of the above-mentioned pesticides in their mixtures were not additive.
Advanced integrated wastewater pond systems for nitrogen removal
Authors: Green F. Bailey , Bernstone L. S. , Lundquist T. J. , Oswald W. J. 
Published: May 2018

Wastewater treatment lagoons are well known for their effectiveness in removing biochemical oxygen demand, suspended solids, and pathogens of sewage origin. Their performance in removing fixed nitrogen is somewhat less recognized and documented.
Advanced Integrated Wastewater Pond Systems (AIWPSs), developed at the University of California, Berkeley's Engineering Field Station and constructed at several locations in California and elsewhere, do permanently remove significant amounts of nitrogen from wastewater streams. A major part of this removal can be attributed to the unique design of AIWPSs. Because the unique characteristics of AIWPSs are not yet widely known and understood in the wastewater treatment field a somewhat detailed description of AIWPSs is in order.
First, the basis for the name Advanced Integrated Wastewater Pond Systems will be explained. The termadvanced is used because the design of AIWPSs represents an advancement over that of conventional waste stabilization ponds. The term integrated is used because these systems involve a number of well known and lesser known unit processes brought together in optimal sequence. The term pond is used because the individual bioreactors of an AIWPS are primarily constructed of earthwork. The term systems is used because the ponds are sequentially arranged and hydraulically controlled to optimize their multiple unit processes. The term wastewater is included to distinguish the function of these ponds from other types of water impoundments.
High rate algal oxidation ponding for the treatment of tannery effluents
Authors: Rose P. D. , Maart B. A. , Dunn K. M. , Rowswell R. A. , Britz P. 
Published: May 2018

The growth of Spirulina sp has been observed in tannery effluent stabilization ponds. The development of a Spirulina-based High Rate Oxidation Pond was undertaken and both substantial remediation and odour reduction were achieved. Accumulating alkalinity associated with algal growth in the pond cascade was successfully used to reduce the ammonia toxicity effects on Spirulina productivity.
Evaluation of the feed value of harvested biomass was undertaken in Artemia salina, chickens, abalone and rainbow trout. A Spirulina-based High Rate Algal Oxidation Ponding process has been shown to present a potential opportunity factor in the form of value-added biomass providing a novel dimension to the treatment of tannery effluents.
New method for studying the hydraulic behaviour of tanks in series -- application to aerated lagoons and waste stabilization ponds
Authors: Naméche T. , Vassel J. L. 
Published: May 2018

All attempts to modelize and wastewater treatment process must go through the imperative knowledge of its mixing characteristics. Such a knowledge calls for the realization of tracing experiments, classically one per basin; an operation that becomes rapidly tedious, especially when it has to be repeated for a series of reactors.
The transfer function theory would allow to avoid such a multiplication of tracing operations. The transfer function which characterizes every system is indeed equal, under well defined initial conditions, to the Laplace transform of the distribution of residence times (R.T.D.) in this same reactor. The R.T.D. can then be calculated from the transfer function by a deconvolution process.
The main interest of this method consists in the fact that, unlike the R.T.D. the transfer function can be evaluated from any input/output signals whatsoever. Thus, the hydraulic pattern of a series of reactors can be easily and, more important, individually studied by means of tracer concentrations measured during only one tracing experiment at the exit of each basin.
The only difficulty in applying this method lies in the choice of the deconvolution procedure used to estimate the R.T.D. Four different methods of calculation are proposed and compared:
* deconvolution by Fourier transforms.
* deconvolution by multilinear regression.
* deconvolution by the algebraic resolution of a set of n equations with n unknowns.
* adjustment by the least-square method to an n order ARX model.
The last mentioned gives the best results. This method provides, for each pond, different parameters like Peclet number, percentage of dead-space or short-circuits. From these results, correlations between dispersion numbers and other state variables can be evaluated. Finally several hydraulic models (completely-stirred, dispersive plug flow, completely mixed tanks in series) may be simulated and compared with observed R.T.D.s.
Modelling solid transport in building drainage systems
Authors: Swaffield John A. , McDougall John A. 
Published: May 2018

The transient flow conditions within a building drainage system may be simulated by the numerical solution of the defining equations of momentum and continuity, coupled to a knowledge of the boundary conditions representing either appliances discharging to the network or particular network terminations. While the fundamental mathematics has long been available, it is the availability of fast, affordable and accessible computing that has allowed the development of the simulations presented in this paper.
A drainage system model for unsteady partially filled pipeflow will be presented in this paper. The model is capable of predicting flow depth and rate, and solid velocity, throughout a complex network. The ability of such models to assist in the decision making and design processes will be shown, particularly in such areas as appliance design and water conservation.