bluuebunny/crossref_metadata_2025_split huggingface dataset:
A method for describing biofilm surface roughness using geostatistical techniques
Authors: Gibbs J. T. , Bishop P. L. 
Published: May 2018

Biofilm reactors, such as rotating biological contactors (RBCs) and trickling filters, have been used to treat both municipal and industrial waste streams. One fundamental property of biofilms which may affect their performance is surface roughness, or the magnitude of variability in height over the structure's profile. This property has an effect on the rate of diffusion of nutrients into the biofilm for degradation through its influence on the thickness of the concentration boundary layer.
The method presented here to quantify the surface characteristics of a biofilm involves the in situ analysis of biofilm surface profile data collected at discrete points. For each point, a microprobe is lowered from some datum above the surface, and the distance down to the biofilm surface is measured at that point. Statistical analysis performed on the data set produces the correlation coefficient between heights on the biofilm surface at various separation intervals. A graph relating the correlation coefficient to the separation interval between heights is constructed from many points to determine the length over which points with low correlation can be collected. A set of nearly independent height data collected at that length interval is then analyzed for mean and standard deviation. The resulting statistics are characteristic of the magnitude of the variability between independent heights on the surface profile, and can be used to compare and contrast the roughness of biofilm surfaces.
This method was used to define the roughness of artificial and real biofilm surfaces. Artificial biofilms, which were made from agar roughed with sand paper of varying grit size, were found to have distinct and consistent roughness, as determined by this method. It was useful to compare the standard deviation (roughness) of real biofilms to these values, because the roughness of sand paper is easily observable, and standardized.
Environmental impact of nutrients from nordic fish farming
Authors: Enell M. 
Published: May 2018

During the last 20 years there has been an interesting development of the Nordic fish farming, with regard to the feeding and farming technology and to the increase in production quantities. During the period 1974-1994 the production increased from 15,800 to about 250,000 tonnes/year. In 1974 the major part of the production was in Denmark, and in 1994 the major part was in Norway. The nutrient impact of fish farming on surrounding sea areas is mainly a function of the feed coefficient, the feed composition and metabolic processes in the fish. The comprehensive development of the feed composition and the feeding technology has resulted in reduced load of unmetabolized nutrients from fish farms, calculated per tonne fish produced. In 1974 the mean Nordic feed coefficient was 2.08 and in 1994 the coefficient was 1.25. Feed coefficients of 1.0-1.1 are now reported for Danish and Norwegian freshwater and marine fish farms. The nitrogen (N) and phosphorus (P) content of the feed has decreased, in addition the quality of the nutrient substances in the feed has changed, especially for N. The N content has decreased from 7.8 to 6.8% during the period 1974-1994 and the content of P has decreased from 1.7 to 0.7% during the same period. This development of the feed coefficient and the feed composition has resulted in a present load from a typical Nordic fish farm of 55 kg N and 4.8 kg P/t fish produced. The figures for 1974 were 132 kg N and 31 kg P/t fish produced.
The Nordic fish farming production in 1994 resulted in a load of about 13,750 t N and about 1,200 t P on the actual recipients. The load from the Swedish, Finnish and Danish fish farming operations, with the Baltic Sea and the Skagerrak as the recipients, is negligible in comparison with other pollution sources. The quantities of N and P from the fish farming are equal to 0.5% of the atmospheric deposition on the sea surface and 3% of the atmospheric P load. Norwegian, Icelandic and the Faroe Islands fish farming operations are using the North Sea and the Norwegian Sea as the recipients. However, the nutrient load from single fish farms in certain coastal and inland water bodies can be significant and must be considered in the impact assessment together with other sources.
Formulation of fish diets with reduced phosphorous content
Authors: Jacobsen C. , Børresen T. 
Published: May 2018

The reduction of phosphorous waste from farmed rainbow trout (Oncorhynchus mykiss) was attempted by feeding diets of reduced P content. The protein source was fishmeal in which the bone fraction had been removed. This was achieved either by solubilizing the fish material (press cake) by enzymatic treatment and subsequent filtering, or by removing the fish bones by a skin/bone separator. Two fish species were used, sand eel (Ammodytes marinus) and sprat (Sprattus sprattus). Due to the small size of the fish, only bones were retained in the skin/bone separator. Traditional fishmeal from the same species were used for control experiments. The fishmeal samples were used together with other ingredients in a traditional extruded dry feed formulation (Ecolife 19).
The diets were used in full scale experiments in a fresh water fish farm in Denmark, as well as in small scale experiments in aquaria. Direct calculations on the feed conversion ratio and the specific growth rate on both experiments showed that the enzyme treated codes performed less well than the other codes. However, when compensating for the different energy content of the diets, the enzymatic treatment did not give rise to a higher feed conversion ratio, nor did it give rise to a lower average growth rate than the other codes. It was not possible to make any final conclusions with respect to the effect of the enzymatic treated fishmeal on the pollution risk from P. This was due to large variation on the P determinations.
Effects of dietary protein/energy ratio, ration size, dietary energy source and water temperature on nitrogen excretion in rainbow trout
Authors: Médale F. , Brauge C. , Vallée F. , Kaushik S. J. 
Published: May 2018

Postprandial nitrogen excretion was measured on groups of rainbow trout of mean body weight (MBW) 35g, fed, from maintenance to near satiation, diets containing graded levels of digestible energy (14 to 20 kJ/g dry matter) with digestible protein (DP)/digestible energy (DE) ratios of 18 and 23 mg/kJ at each protein level (DP: 32.5 or 37% dry matter). Irrespective of the diet and the ration size, urea-N excretion amounted to 15-16% of ammonia-N excretion. The higher the dietary DP/DE ratio, the greater was the amount of ammonia excreted. At high ration levels (1.5% and 2% of MBW/d), N excretion was 39-40% of digestible N intake for diets with a DP/DE ratio of 18 mg/kJ and 44% of digestible N intake for diets with a DP/DE ratio of 23 mg/kJ irrespective of the dietary protein level. At lower ration levels, N excretion as percent of N intake was higher than at higher feeding levels.
Another experiment was performed to compare the effect of dietary lipid and digestible carbohydrate on ammonia excretion in rainbow trout reared at two water temperatures (8°C and 18°C). Neither water temperature nor dietary sources of non-protein energy had any significant effect on N excretion expressed as proportion of digestible N intake.
Seawater quality at industrial effluents discharge zone
Authors: Al-Muzaini S. , Beg M. U. , Al-Mutairi M. , Al-Mullalhah A. 
Published: May 2018

Shuaiba Industrial Area (SIA) accommodates 38 plants, of which 15 are located in the eastern sector and the other 23 in the western sector. The factories, being near the shore of the Arabian Gulf, discharge their wastewater directly into the Gulf after in-plant treatment.
How far industrial effluents influence the marine environment was assessed using Microtox toxicity assays of seawater samples collected twice a week for six months from two stations located upstream and downstream of SIA.
Out of 50 samples each collected from Station No 1 and Station No 2, only two samples from the former showed toxicity, whereas at the latter site ten samples showed medium to high levels of toxicity. The higher incidence of toxicity in the downstream area may be due to the mixing of effluent from individual discharges and indicate some inefficiency of the effluent treatment process. The study revealed that the biological assay provides effective assessment of water quality.
The influence of growth conditions on odor-compound production by two chrysophytes and two cyanobacteria
Authors: Rashash D. M. C. , Dietrich A. M. , Hoehn R. C. , Parker B. C. 
Published: May 2018

The influence of several environmental factors (e.g., light intensity, temperature, nitrogen, and phosphorus) on population density and odor-compound production of two chrysophytes, Synura petersenii and Dinobryon cylindricum; and two cyanobacteria, Anabaena laxa and Phormidium calcicola was investigated. The odors associated with each alga were evaluated by flavor profile analysis (FPA) at several intervals during their initial culturing in defined media. Algal cell and media extracts were analyzed individually by capillary gas chromatography-mass spectrometry (GC-MS). Both cyanobacteria produced geosmin (“earthy” and “corn” odors); however, the P. calcicola also produced relatively large amounts of MIB (“musty-earthy” odors). Both chrysophyte cultures contained 2t,4c,7c-decatrienal (“fishy” odor); and in addition, 2t,6c-nonadienal (“cucumber” odor) was isolated from the S. petersenii.
Young cultures of Anabaena laxa (e.g., &lt;20 days) retained most of the geosmin produced. Throughout its population growth, more than 80 percent of the MIB and geosmin produced by P. calcicola was detected in the media rather than in the cells. Synura petersenii,produced more 2t,4c,7c-decatrienal than 2t,6c-nonadienal and retained nearly 90 percent of both compounds throughout the algal population growth. Dinobryon cylindricum produced 2t,4c,7c-decatrienal, and, like the S. petersenii, retained most of the compound. Greater production of the compounds by the two chrysophytes was apparently associated with log-phase growth rather than specific environmental conditions; extended log-phase growth (and prolonged production of compounds) was observed in the S. petersenii culture during the low-temperature treatment.
Primary-secondary flotation of three municipal wastewaters: pilot-scale study
Authors: Krofta M. , Miskovic D. , Burgess D. 
Published: May 2018

A pilot system containing a particularly designed configuration of primary flotation unit and a combined flotation-filtration clarifier, was used for advanced municipal wastewater treatment.
The system which was investigated demonstrated the feasibility of municipal wastewater treatment by the flotation separation of fluid and coagulated-flocculated solids (Total suspended solids (TSS), organic load, Phosphorous (P), Total Kjeldahl Nitrogen (TKN)) without using microbiological oxidation.
The particular objective herein was to create a preliminary approach to theoretical evaluation of positive pilot-study results in the form of two kinetic models.
Based on positive pilot results, and kinetic analysis, the following conclusions were reached:A double-stage flotation/filtration system might be a viable alternative for municipal wastewater treatment.Empirical models and prediction developed here reflect the kinetics of the removal of coagulated and flocculated solids by flotation.
Strategic approaches to the development and implementation of water quality management plans
Authors: Brown S. A. P. , van Niekerk A. M. 
Published: May 2018

Catchment water quality management plans are central to the Department of Water Affairs and Forestry's (DWAF) water quality management strategy. Catchment plans provide a coherent framework to ensure that fitness for use is achieved at catchment level.
This paper describes DWAF's perspective on and approach to key aspects associated with the development and implementation of catchment water quality management plans. It expands on the role and composition of a catchment water quality management plan; the guiding principles inherent to the development of a management plan; the key success factors ensuring implementability; key aspects associated with the development of the plan, public participation, project structure, water users and setting water quality objectives and various aspects in DWAF's approach for future consideration.
Broadening participation in integrated catchment management for sustainable water resources development
Authors: Maaren H. , Dent M. 
Published: May 2018

The need to broaden participation and thereby democratise the process of integrated catchment management for sustainable water resources development is fundamental to peaceful, holistic and equitable progress in Southern Africa. This need is urgent in a region racked with conflict and riven by inequalities that exacerbate the already complex situation surrounding the sustainable development of scarce water resources.
The key questions, however, relate to the strategies which organisations can employ both internally and inter-organisationally to empower people to play a meaningful role in the processes that will lead to the attainment of these goals.
This paper explores the possibilities for such strategies and moves the discussion beyond purely scientific needs to examine the technological and human resources and cultural and organisational transformations which are taking place. It also suggests some transformations that are still required for such strategies to succeed.
Assessment of the success of the Peel-Harvey estuary system management strategy - a Western Australian attempt at integrated Catchment Management
Authors: Humphries Robert , Robinson Sally 
Published: May 2018

The Peel-Harvey estuary and its catchment have been the subject of intensive investigation and management since the late 1970s, because of concern about worsening algal blooms and their associated impacts. After diagnosis of the problem, possible management options were assessed in the light of the available technical information, and a management strategy developed and implemented.
Various Integrated Catchment Management (ICM) approaches have been used, including voluntary reduction of fertilizer use, and the construction of a new channel to the ocean to achieve an appropriate socio-environmental solution. Innovative approaches were also taken in developing statutory and non-statutory management targets and land-use controls and guidelines. To date these measures appear to have been successful, although some of them are vulnerable in the long term.
This is currently the best Australian example of an ICM approach to the management of a complex environmental problem which has actually been implemented. It is also a good example on a world scale of addressing an environmental problem using a systems approach with an appropriate socio-environmental solution.
Quality control in environmental microbiology compared with chemistry: what is homogeneous and what is random?
Authors: Tillett Hilary E. , Lightfoot Nigel F. 
Published: May 2018

Organism counts from environmental quality control (QC) samples, such as indicators in water, will show variation even if they come from a single well mixed batch. This is due to random variation and there may be additional effects from organism behaviour. Thus the samples are not homogeneous in their content. Samples for chemistry will also be variable in their content but this may be at a level below the limit of detection and thus the observed measurements will show apparent homogeneity.
Organism counts may take 24 hours to achieve and longer to confirm. A chemical result can often be obtained rapidly. Assessment of performance with microbiological counts usually requires the accumulation of evidence over several samples. A judgement can be attempted with each chemical QC result.
QC in environmental microbiology is an important and growing field. The apparent imprecision and slowness in assessing performance is unavoidable. Sound quality assurance programmes will accommodate these factors.
Waterborne disease incidences in the Mediterranean region as a function of microbial pollution and T90
Authors: Kocasoy G. 
Published: May 2018

Among the different impacts of coastal tourism on the environment, its effect on public health has a special significance. The large increase in population during the high season usually results to an increase in the amount of wastewater produced. If the necessary infrastructure - which most of the time the developing countries lack - for handling these wastes is not available, the sea is polluted causing serious problems. To investigate the effects of sea pollution onpublic health a survey has been conducted in Bodrum and Çeşme; the two most important touristic resorts in Turkey. A questionnaire about the health problems which tourists suffer as well as their culinary habits, swimming habits etc. was distributed. At the same time the pollution level in the sea was determined in the form of coliform concentration. As a result, it was proved that those swimming in polluted waters suffer from gastro-intestinal diseases more than others. Furthermore foreigners and children had been proved to be more susceptible to pollution due to the lack of immunity.
The purpose of the present study is to investigate the effect of the rate of pollution as well as of the microbial self purification capacity (T90) on public health.
Multivariate micropollutants analysis in marine waters
Authors: Librando V. , Magazzù G. , Puglisi A. 
Published: May 2018

The monitoring of water quality today provides a great quantity of data consisting of the values of the parameters measured as a function of time. In the marine environment, and especially in the suspended material, increasing importance is being given to the presence of organic micropollutants, particularly since some are known to be carcinogenic. As the number of measured parameters increases examining the data and their consequent interpretation becomes more difficult. To overcome such difficulties, numerous chemometric techniques have been introduced in environmental chemistry, such as Multivariate Data Analysis (MVDA), Principal Component Analysis (PCA) and Partial Least Squares Regression (PLSR).
The use of the first technique in this work has been applied to the interpretation of the quality of Augusta bay, by measuring the concentration of numerous organic micropollutants, together with the classical water pollution parameters, in different sites and at different times. The MVDA has highlighted the difference between various sampling sites whose data were initially thought to be similar. Furthermore, it has allowed a choice of more significant parameters for future monitoring and more suitable sampling site locations.
Using an array of ultrasonic velocity transducers to improve the accuracy of large sewer mean velocity measurements
Authors: Hughes A. W. , Longair I. M. , Ashley R. M. , Kirby K. 
Published: May 2018

Portable in-sewer Doppler velocity measuring equipment has been available for a number of years. However in large sewers (typically greater than one metre diameter) the accuracy of these devices for large flow depths can be very poor. This paper describes a system, developed by the authors, that enables the determination of a velocity profile across the section of the flow in a large sewer. The velocity profile information obtained can then be used to determine a more accurate estimation of the mean velocity of flow in the large sewer.
In the paper the hardware and software developed to form the Doppler Transducer Velocity Array System is discussed. Installation of the system in a large sewer and subsequent field testing of the system are also discussed, with results of the field testing included. The paper also shows how the results obtained were used to produce 3-dimensional surface plot graphs that show the variation of velocity against time across a section of the sewer flow.
Portable sewage flow sensors - their calibration and accuracy
Authors: Watt I. A. , Jefferies C. 
Published: May 2018

An accurate assessment of flows is essential for any study of the hydraulic performance of a sewer system or the pollutant removal efficiency of an effluent treatment plant. Flow measurement relies either on fixed flumes, usually at the inlet to treatment works, or on portable in-sewer depth and velocity sensing equipment which is periodically calibrated to check on its accuracy. It is becoming increasingly important to optimise the operation of sewage treatment works both to ensure consent standards are met, and to minimise the total pollution load reaching the environment. Consequently, accurate flow measurements at a number of locations are required to complement quality performance measurements.
The field equipment normally used for measuring flows in either full or part-full pipes employs the ultrasonic Doppler-shift principle for mean velocity, and some form of depth measurement, typically a pressure transducer. The quality and accuracy of the data obtained may be highly variable, and detailed quality assurance checks can be of great value. This paper presents the results of a number of studies in which the accuracy of velocity measurement using doppler-shift has been an important factor. Assessments of the overall accuracies and reliability of the flow measurement equipment are assessed by examining data from a number of studies. Factors such as the frequency of calibration, the range of flow states at which calibration has been carried out and the concentration of suspended solids were all found to be important. Ranges of accuracy of data gathered are presented.
Requirements with respect to on-line analyzers for N and P
Authors: Schlegel S. , Baumann P. 
Published: May 2018

For some years now, measuring instruments have been employed at wastewater treatment plants in Germany to continuously monitor ammonia (NH4), nitrate (NO3) and phosphate (PO4). Altogether, almost 3,000 monitoring units are currently in use at a total of approximately 600 treatment plants of all sizes. In addition to continuously monitoring the treatment plant effluent and individual treatment processes, these allow the adjustment and control of plant units and, thus, a saving in operating costs, particularly with respect to the consumption of energy and chemicals.
In addition to characteristic data on the instruments, investment and operating costs play a major role when deciding to purchase measuring instruments of this type.
Therefore, the German Technical Wastewater Association's (ATV) working group on the “Automation of Wastewater Treatment Plants” resolved to prepare, within the framework of the ATV rules, a code of practice on “Requirements with respect to On-line Analyzers for Nitrogen and Phosphorus Compounds” (M 269). The purpose of this is to provide planners, operators and public authorities with advice on the design and reliable operation of on-line analyzers and the appurtenant peripheral equipment. The present text describes the essential contents of M 269.
Experiences with on-line measurements at a wastewater treatment plant for extended nitrogen removal
Authors: Nyberg U. , Andersson B. , Aspegren H. 
Published: May 2018

On-line sensors have been used at the Klagshamn treatment plant to measure the concentration of suspended solids in the raw wastewater, in the primary effluent and in the secondary effluent. By means of the sensors the short-term performance of the primary and the secondary treatment have been evaluated. The sensors are important when the total discharges of pollutants from the plant are to be considered during storm water events.
Parallel on-line measurements and laboratory analyses of grab samples have shown that the used sensor type, based on NIR technique, reflects the concentrations rather well. The on-line measurement in the raw wastewater is rather unreliable due to clogging which means that using this application for control can be questioned.