bluuebunny/crossref_metadata_2025 huggingface dataset:
Aromatic VOC emissions from a municipal sewer interceptor
Authors: Corsi Richard L. , Quigley Christopher J. , Melcer Henryk , Bell John
Published: May 2018

Municipal and industrial sewers have come under increased regulatory scrutiny as sources of volatile organic compound (VOC) emissions to the ambient atmosphere. A well-ventilated municipal sewer interceptor that receives significant quantities of VOC-laden industrial wastewater was studied to quantify VOC emissions. Headspace outgassing rates across four manhole covers were as high as 2300 m3/h. Emissions were greatest for toluene, approaching 100 g/h from a single manhole cover at the mid-point of the 24-hour event. Significant diurnal and weekday/weekend trends were observed. Emissions from a single manhole cover rivaled or exceeded those summed over aerated grit chambers and aeration basins at four large municipal wastewater treatment facilities in Southern Ontario. The primary source of VOC stripping was observed to be a series of large drop structures, with aromatic VOC stripping efficiencies ranging from 25 to 38% across two drops. Finally, an existing model that predicts VOC emissions from sewers was observed to reasonably predict measured stripping efficiencies. An important conclusion of this study is that large fractions of VOCs may be removed from wastewater and emitted to the ambient atmosphere prior to entering a downstream treatment facility.
Multipurpose filters with ion-exchanger for the equalization of ammonia peaks
Authors: Oldenburg Martin , Sekoulov Ivan
Published: May 2018

In this study the use of zeolites as ion-exchangers for equalization of ammonia peak loadings in aerated biological activated filters was investigated. For this use zeolites were mixed with a filter medium and the nitrifying filter was loaded with ammonia peaks for two hours at different flow rates. It could be demonstrated that during the phase of higher inflow concentrations the zeolite was collecting ammonia. When the influent concentration decreased ammonia was desorbed from the zeolite and could be nitrified by the bacteria growing on the filter medium. It was shown that additional zeolites can equalize variations of ammonia, especially in filter units which are working at a high nitrification rate and which are very sensitive to varying influent conditions. During the operation time of the filter no separation of the zeolite by higher hydraulic loading or by backwashing could be recognized. So the upgrading of nitrifying filters with zeolite represents an additional security for effluents containing oscillating ammonia concentrations.
Experimental procedures characterizing transformations of wastewater organic matter in the Emscher river, Germany
Authors: Løkkegaard Bjerre H. , Hvitved-Jacobsen T. , Teichgräber B. , te Heesen D.
Published: May 2018

The Emscher river in the Ruhr district, Germany, is at present acting as a large wastewater collector receiving untreated and mechanically treated wastewater. Before the Emscher flows into the river Rhine, treatment takes place in a biological wastewater treatment plant. The transformations of the organic matter in the Emscher affect the river catchment, the subsequent treatment and the river quality. This paper focuses on evaluation of methods for quantification of the microbial transformations of wastewater in the Emscher with emphasis on characterization of wastewater quality changes in terms of biodegradability of organic matter and viable biomass. The characterization is based on methods taken from the activated sludge process in wastewater treatment. Methods were evaluated on the basis of laboratory investigations of water samples from the Emscher. Incubation in batch reactors under aerobic, anoxic and anaerobic conditions were made and a case study was performed. The methods described will be used in an intensive study of wastewater transformations in the Emscher river. This study will be a basis for future investigations of wastewater quality changes in the Emscher.
Contaminant migration from sanitary landfill leachate through soil monoliths
Authors: Radenkova-Yaneva Magdelinka , Kostakeva Emilia , Toshev Dimiter
Published: May 2018

It is well known that the leachates from solid domestic waste sanitary landfills are heavily polluted with organic and inorganic substances. As they are of a potential danger for the environment, their uncontrolled seepage is avoided in the modern sanitary landfills by means of suitable insulation. This is mostly made of natural materials with a low filtration coefficient.

The present paper considers the results of the filtration characteristics, studying natural clayey soil model liners. The leachate contaminants distribution from the sanitary landfill in Sofia (Suhodol) is traced out in different liner depths. The mechanism of pollutant attenuation in the liners is considered. It is found that a part of the leachate components (Fe, Mn, SO42−, PO43−) stays in clayey liners. Besides, as a result of pore colmatation the permeability of the liners is decreased. It is shown that soil monoliths with a proper thickness might serve as a sufficiently safe barrier against leachate filtration in adjacent aquifers. On the base of the results obtained the thickness of the clay liners in the solid domestic waste sanitary landfills could be optimized.
A newly isolated fungus participates in the corrosion of concrete sewer pipes
Authors: Kyeoung-Suk Cho , Mori Tadahiro
Published: May 2018

The final microflora in the corrosion process of concrete sewer pipes was investigated. When the corroded sample was examined using several media, bacterial colonies were found only on acid media (pH 2.5); fungi were detected on neutral solid media (pH 6.5) as well as on acid media (pH 2.5). The acidophilic bacterial colonies were identified as Thiobacillus thiooxidans using a specific identification method for species of acidophilic thiobacilli. The dark green fungi that appeared on the isolation media showed similar morphological characteristics, even though the media used for isolation varied in pH and nutrient. The fungi showed tolerance against acid, although the optimum pH for their growth was neutral. The results showed that the severely corroded sewer pipe was inhabited by two kinds of microorganisms, Thiobacillus thiooxidans and the fungi. An isolated fungus, strain OMSOfl, could oxidize sulfide to thiosulfate. Thiosulfate can be utilized by T. thiooxidans as an energy source, and is converted to corrosive sulfate. Continued vigorous growth of T. thiooxidans presumably depends on a mutualistic relationship with the fungus. It is proposed that a close association between the two microorganisms accelerates the corrosion of concrete sewer pipes.
Flow induced vibrations, drag force, and pressure drop in conduits covered with biofilm
Authors: Lewandowski Z. , Stoodley P.
Published: May 2018

Biofilm was grown in closed conduit reactors under turbulent flow conditions. Structural development of the biofilm suggests that individual microcolonies behave like blunt bodies shedding vortices. The microcolonies assumed elongated forms, termed “streamers”, possibly because of an exerted pressure drag force. The streamers when entrained in the water flow vibrated rapidly dissipating kinetic energy from the bulk liquid. The energy was transferred through the biofilm causing the underlying microcolonies to oscillate. The measured pressure drop was partially attributed to the loss of energy due to these flow induced vibrations and oscillations.
The Fraser River basin – towards sustainability
Authors: Pomeroy W. M.
Published: May 2018

The Fraser River Basin occupies approximately one quarter of the area of British Columbia ranging from undeveloped forests to heavily urbanized centres. Competing demands are continually being made on the system with respect to preservation of the natural environment and economic development. In response to increasing stresses, the six year Fraser River Action Plan was initiated in 1991 to reduce pollution, enhance environmental quality, and develop an integrated basin management program based on sustainability. Activities addressing the first two are under way in the areas of pollution abatement, environmental quality and research, enforcement and compliance, and habitat restoration and conservation. Partnerships are critical to implementing a successful integrated management program. The Fraser Basin Management Program balances current social and economic needs with environmental conservation to achieve sustainability. Smaller scale management programs exist within the basin to address the highly urbanized/industrialized Fraser estuary (Fraser River Estuary Management Program) and the Port of Vancouver/Burrard Inlet (Burrard Inlet Environmental Action Program). Environment Canada, in partnership with others, is cleaning up pollution and establishing effective sustainable management programs, before the conflicts between environment and economy reach a critical point. Results to date are encouraging.
From one-sided promotion of individual interests to integrated water management in the Rhine basin
Authors: Huisman Pieter
Published: May 2018

In autumn 1971, water pollution and poison incidents caused death in the Rhine. Aquatic life disappeared. The rulling opinion was: Clean up the waste water and life will return. It proved to be a half-truth. After treatment of waste water some organisms returned, others, particularly the migratory fish, did not. Barrages and weirs have decimated the migratory fish. Waste water gave only the final knock-out for these species. Slowly understanding arose for a harmonization between human interests and the ecosystem. In course of time the Rhine-states replaced the one-sided promotion of individual interests by the concept of integrated water management, a prerequisite for sustainable development. This contribution reflects the process of changing minds.
Evaluation of a coupled mass transport-biofilm process model using dissolved oxygen microsensors
Authors: Cunningham A. B. , Visser E. , Lewandowski Z. , Abrahamson M.
Published: May 2018

A 2-dimensional model has been developed which couples hydrodynamics, solute transport and reaction in a steady state biofilm system of irregular geometry under laminar flow. Biofilm thickness is initially specified over the domain and remains constant during the simulations. The Navier-Stokes equations are coupled with advection-diffusion-reaction equations describing oxygen transport and solved using finite differences. This model facilitates computational investigation of fluid velocity and solute concentration distributions in proximity to the fluid-biofilm interface. Model evaluation has been carried out using dissolved oxygen profiles measured by microsensors in a rectangular open channel with a 300 μm (approximate) artificial biofilm composed of alginate gel with an 8×1010 cells/ml concentration of Ps. aeruginosa cells. Significant variability in dissolved oxygen profile shape was observed at three locations on the artificial biofilm. Model simulations of these experiments facilitated a direct comparison between observed and computed values of dissolved oxygen concentration in the vicinity of the fluid-biofilm interface. Simulated profiles agreed closely with measured profiles at all three locations.
Agricultural best management practices and surface water improvement and management
Authors: Anderson D. L. , Flaig E. G.
Published: May 2018

Restoration and enhancement of Lake Okeechobee and the Florida Everglades requires a comprehensive approach to manage agricultural runoff. The Florida Surface Water Improvement and Management (SWIM) Act of 1987 was promulgated to develop and implement plans for protecting Florida waters. The South Florida Water Management District was directed by Florida legislature to develop management plans for Lake Okeechobee (SWIM) and the Everglades ecosystem (Marjory Stoneman Douglas Everglades Protection Act of 1991). These plans require agriculture to implement best management practices (BMPs) to reduce runoff phosphorus (P) loads. The Lake Okeechobee SWIM plan established a P load reduction target for Lake Okeechobee and set P concentration limitations for runoff from non-point source agricultural sources. Agricultural water users in the Everglades Agricultural Area (EAA) are required to develop farm management plans to reduce P loads from the basin by 25%. The Everglades Forever Act of 1994 additionally emphasized linkage of these landscapes and consequent protection and restoration of the Everglades. Agricultural BMPs are being developed and implemented to comply with water management, environmental, and regulatory standards. Although BMPs are improving runoff water quality, additional research is necessary to obtain the best combination of BMPs for individual farms. This paper summarizes the development of comprehensive water management in south Florida and the agricultural BMPs carried out to meet regulatory requirements for Lake Okeechobee and the Everglades.
Characterization of biofilms on corroded concrete surfaces in drinking water reservoirs
Authors: Herb Stefan , Stair Julia O. , Ringelberg David B. , White David C. , Flemming Hans-Curt
Published: May 2018

The surface of concrete in drinking water reservoirs is frequently covered with a mineral coating. Since the beginning of the 1980's, there has been an increasing number of reports of brown spots within which the coating matrix was weakened. The diameter of the spots ranged from a few millimetres up to 10-20 centimetres. Cleaning measures resulted in removal of the spot material revealing that shallow pits had formed in the coating. The deeper underlying concrete body was usually unaffected. Although the removed material was shown to contain a substantial microbial biomass, there was no indication of an elevated microbial contamination in the actual drinking water as detectable by the German standard drinking water testing method. The microbial biomass from the damaged sites of six reservoirs was quantified using ester-linked phospholipid fatty acids (PLFA). Population densities were shown to range between 5 × 107 and 5 × 108 cells g−1 in samples collected from non-chlorinated reservoirs and 106 cells g−1 in samples from a chlorinated one (assuming 0.5 fM PLFA equivalent per cell). The recovery of PLFA indicated that physiologically active populations were present in all of the spots sampled and an analysis of the PLFA proriles revealed that the microbial community contained a large percentage of gram negative aerobic heterotrophs. Differences were found between the PLFA patterns of samples from different reservoirs. The fact that a consistent PLFA profile was not recovered from each spot sampled indicates the absence of a single dominant organism. Methyl cellulose (MC) was identified as a possible nutrient source based on the successful growth of bacterial strains isolated from the damaged areas on hydrolyzed coating material. How MC may becomes bioavailable in the reservoirs remains still unclear.
Environmental aspects of the restoration of river ecosystems in The Netherlands
Authors: Denneman W. D. , de Pree A. , Reininga G. A. O. , van der Braak J.
Published: May 2018

In The Netherlands, an integrated policy concerning the restoration of river ecosystems has been developed by the National Government. For these rehabilitation projects, TNO was asked by the Dutch government to investigate the environmental problems these project will face during realization. To reach this goal, a PC meta-information system called MIMIKRI has been developed. An example for the nature rehabilitation project “Gelderse Poort”, one of the priority projects along the Dutch rivers Rhine and Waal (Walloon) will be given.
Prediction of effects of measures to reduce eutrophication in surface water in rural areas – a case study
Authors: van der Kolk J. W. H. , Hendriks R. F. A.
Published: May 2018

In the Bergambacht polder in The Netherlands, the surface water system is highly eutrophic. Owing to this high nutrient concentration, duckweed grows abundantly. To reduce the nutrient concentrations in the surface water, remedial measures are needed. To predict the effectiveness of three measures, a combination of a nutrient leaching model and a water quality model for nutrients in the surface water system was used. The scenarios formulated on the basis of these measures were simulated over a period of 35 years. Removing duckweed results in a substantial reduction of nitrogen and phosphorus. Improving the water purification plants results in a small reduction in the average nutrient concentrations. Dredging the total sediment layer results in a large reduction of phosphorus concentrations, but leads to an increase in nitrogen concentrations. The three measures combined will not improve the nitrogen concentration 30 years after implementation, but the phosphorus concentration will be reduced by 80% compared with 1990.
Relative importance of mean velocity and bed shear on biofilm accumulation in open-channel flows
Authors: Lau Y. L.
Published: May 2018

Experiments on biofilm growth were carried out to investigate whether bottom shear stress or average velocity is more appropriate as a parameter for investigating the effect of flow on biofilm formation in channel flows. The tests were conducted in two identical channels located side by side, using the same water supply. By having different bottom slopes or roughness elements, or both, tests were set up in which the flows in the two channels had equal velocities but different bottom shear stresses or equal bottom shear stresses but different velocities. Porcelain balls were used as bottom roughness elements and the accumulation of biofilm on the balls was monitored. Comparisons of the rates of biofilm accumulation indicate that the average velocity is the more important parameter.
The effect of changing inter process and final disinfection reagents on corrosion and biofilm growth in distribution pipes
Authors: Holden B. , Greetham M. , Croll B. T. , Scutt J.
Published: May 2018

Anglian Water are currently up-rating the treatment process on all their surface water sources to include ozone to aid clarification and additional GAC contact time for the removal of micropollutants such as pesticides and trihalomethanes in the water. The final disinfection for the high quality water is by either chloramination or chlorination and pumped into a distribution network containing pipes of various materials.

To investigate the effect on the distribution network of chanving from pre-chlorination to an advanced water treatment process, a pipe rig was constructed at Grafham Water Works which included sections of a 60 year old cast iron main and new plastic MDPE pipework. The work was carried out in conjunction with University College London and investigated parameters including assimilable organic carbon (AOC), total organic carbon (TOC) and temperature and monitored their effect on the biofilm growth and corrosion rates.

The biofilm growth and corrosion rates on the coupons inserted into the cast iron pipes of the rig were found to be related to their orientation on the main. Temperature had a significant effect and correlated to bacterial activity.

During the period of investigation Grafham main works also changed over from pre-chlorination to ozonation and samples were taken from the actual distribution system pre and post the process changes. The results from these findings agreed with the pipe rig model, with the overall conclusion that the change from pre-chlorination to ozonation would have little effect on the corrosion and biofilm growth in distribution.
Use of enzyme somase® in the measurement of biofilm using bioluminescence
Authors: Greetham M. , Holden B. , Scutt J.
Published: May 2018

Analysis of the biofilm on a distribution system model pipe rig gave high readings of extracellular adenosine-5′-triphosphate (ATP). The free ATP was assumed to come from dead cells at the base of the biofilm. The levels were large in proportion to the measured cellular ATP and were unstable. This resulted in errors in the calculation of cellular ATP. An enzyme Somase (0.5%) was employed to hydrolyse the free ATP. Increased accuracy of the measurement of cellular ATP was seen.
International watercourses: the World Bank looks toward a more comprehensive approach to management1
Authors: Olem Harvey , Duda Alfred M.
Published: May 2018

This paper examines transboundary water resources management challenges currently being faced across the globe. Lessons learned from Europe, Africa, Asia and North America are outlined on the need for more integrated, ecosystem-based management of these international watercourses and on institutional arrangements for improving management. The World Bank's new Water Resources Management Policy is presented with an emphasis on elements related to a more comprehensive approach that considers integrated land-water management, proper pricing for water service delivery, nonpoint pollution abatement, aquatic ecosystem restoration, and institution building. Also described is a key international funding mechanism for more comprehensively managing international watercourses known as the Global Environment Facility (GEF). Restructed and replenished in 1994, GEF can play a catalytic role in building institutions for better water resources management and in fostering cooperative actions among nations in a basin toward the ultimate goal of making development more environmentally sustainable.
Mathematical modelling of long-term runoff load from rural watersheds
Authors: Sung-Ryong Ha , Kwang-Ho Lee
Published: May 2018

This study aims to develop a quantitative model for calculating the long-term run off loads in reservoir watersheds. By employing geologically based information rather than administrative-district based information and integrating more diverse variables like socio-economic, technological, and natural ones, a more comprehensive model (BlongRM) is developed. The major structure of the model BlongRM consists of a pollutant load calculating stage for each administrative district in which original pollution is generated and washed off, a pollutants load calculation stage for each watershed, and a runoff load calculation stage based on the linear contribution rate matrix. The applicability of the model to practical problem-solving has improved and its usefulness is verified by empirical data. This model will hopely contribute to the development of a lake pollution prevention strategy.
Phosphorus movement through soils and groundwater: application of a time-dependent sorption model
Authors: Ho Goen E. , Notodarmojo Suprihanto
Published: May 2018

Pollution of groundwater, wetlands, rivers, estuaries and near shore waters by phosphorus is now fairly common due to run-off from agricultural areas and wastewater discharges. In the application of fertilisers in agriculture it has been observed that sandy soils result in high phosphorus concentrations in the run-off. On the other hand loamy soils result in less phosphorus run-off. Phosphate-phosphorus sorption by soils has been observed to be time dependent. A model has been developed to describe the movement of phosphorus through soils to take into account the processes of convection, dispersion and time-dependent sorption. The model enables prediction of phosphorus breakthrough in a soil column. A comparison is made of predicted breakthrough curves with results obtained using two types of soil: a sandy soil from Australia and a loamy soil from Indonesia. The model has direct application to field situations where phosphate-phosphorus moves vertically downward through the unsaturated zone to the water table, and horizontally through the groundwater aquifer. Parameters of the model can potentially be derived from simple batch sorption experiments.
Predicting the bed expansion of an anaerobic fluidised-bed bioreactor
Authors: Setiadi Tjandra
Published: May 2018

In this study, the bed expansion of an anaerobic fluidised-bed bioreactor was investigated. The experiments were conducted in a 4.4 cm diameter column with 0.152 mm sand as medium support of the biofilm. The temperature was maintained at 30°C and synthetic wastewater was used. The bed expansion data from the present study and literature data were used to evaluate the applicability of the correlations in predicting the bed expansion of the bioreactors. A correlation between bed expansion or voidage (ɛ) and the particle Reynold's (Re) and Gallileo's (Ga) numbers proposed by Setiadi (1989) ɛ = 1.72 Re0.203 Ga−0.179 was found to predict the bed expansion of anaerobic fluidised-bed bioreactors with better accuracy than any previously published correlations.
Nutrition, animal production and the environment
Authors: Rérat A. , Kaushik S. J.
Published: May 2018

With increasing demographic growth, there will be an ever increasing demand for greater food production over the turn of this century. Seen from today's productivist point of view, this is not too difficult a challenge to meet. Besides socio-economic and geopolitical considerations, it is now of the utmost importance to consider any such increase in food production from a global environmental perspective. Man-made changes to the environment are numerous, some perhaps irredeemable. The essential human activities of agriculture, animal production and fisheries also affect the environment and some quantitative data are available on such impacts.

Each progress in increasing agricultural resources (reclaiming new land areas for agriculture, increase in land productivity, intensification of animal production etc.,) is not without disadvantages (deforestation, pollution of underground water through different contaminants). Intensification of land animal production, facilitated also by progress in biotechnological methods leads to increased contamination of the natural food chain and to the concentration of effluents. Aquatic production, currently undergoing tremendous progress, is also facing several such dangers: over-exploitation of natural resources; slow disappearance of natural breeding grounds; increased pollution of water through industrial, agricultural and aquacultural activities. Every such menace to the future of food production has its solution. Even the application of already available knowledge can prevent further deterioration of our land, air and aquatic environment for sustained production. But, local socioeconomic pressures and lack of concern or education often prevent us from obtaining the ideal balance between food production and environment.
Effects of a microbial phytase on the utilization of native phosphorus by carp in a diet based on soybean meal
Authors: Schäfer A. , Koppe W. M. , Meyer-Burgdorff K.-H. , Günther K. D.
Published: May 2018

The effects of a microbial phytase derived from Aspergillus niger (Natuphos®, BASF AG Ludwigshafen, Germany) on growth, body mineralization, phosphorus retention and phosphorus excretion were investigated in common carp (Cyprinus carpio L.). The test diet used in this study was based on soybean meal, fishmeal and wheat starch resulting in a total P content of 7.3 g/kg dry matter (DM). This diet was supplemented with two levels of monocalciumphosphate (MCP) and additionally with phytase at levels of 500 and 1000 U/kg. Triplicate groups of fish (10 carp/tank) of mean initial weight of 40 g were fed at a level of 20 g/kg W0.8 d−1 for 9 wk at a water temperature of 23°C. There was enhanced weight gain, crude ash content and P content in whole body with increasing dietary P content and phytase supplementation, respectively. The P gain was about 4 g/kg gain when P supply was adequate. Supplementation with phytase improved utilization of native plant P and reduced the P excretion/kg gain significantly by 30% compared with MCP-supplemented diets. This effect of the phytase was confirmed by measurements of the total P digestibility.
Effect of dietary protein:energy ratio on weight gain, body composition, serum glucose and triglyceride levels, and liver function of striped bass
Authors: Woods L. Curry , Yust Doug , McLeod Charles , Subramanyam Mark
Published: May 2018

A 12 week feeding experiment was conducted with juvenile, full sibling striped bass (Morone saxatilis) to evaluate three practical diets with protein:energy ratios of 26.9 (diet 1), 31.1 (diet 2), 35.7 (diet 3) g protein/MJ energy. Survival was high in all three diets, however, growth in diet 1 and 2 was significantly less than in diet 3. Proximate composition of whole fish indicated that striped bass fed Diet 1, with the lowest level of metabolizable energy but the lowest protein:energy ratio, had significantly higher lipid content compared to the remaining diets. Conversely, diet 3, with the highest level of metabolizable energy and the highest protein:energy ratio, was the only diet with an increased whole body protein content. Serum levels of triglycerides increased significantly in all treatments when compared with pre-experimental levels, but were lowest in diet 3. Serum glucose levels dropped from pre-experimental levels in all treatments except diet 1. A linear increase in both lipids and carbohydrates stored in the cytoplasm of the liver hepatocytes was observed with increasing metabolizable energy content of the diets. Hepatocellular swelling was observed in fish fed all three diets. However, the two lower protein:energy ratio diets caused significantly greater swelling of hepatocytes than did the highest protein:energy ratio diet. These data indicate that similar practical diets with less than 34 g protein/MJ may be inappropriate for juvenile striped bass.
Fillet texture of rainbow trout as affected by feeding strategy, slaughtering procedure and storage post mortem
Authors: Færgemand Jacob , Rønsholdt Bent , Alsted Niels , Børresen Torger
Published: May 2018

Due to the enactment of environmental legislation in Denmark, feed expenditure by commercial aquaculture operations has been limited. This development has created a demand for high energy diets, which presently dominate the market place. Such diets limit waste load to the surrounding environment, but is the quality of the fish as end product affected?

It is well established that fillet quality varies according to several factors, including feed composition and feeding regime. An experiment was thus designed to evaluate the effect of differing: i) amount of protein fed, ii) amount of fat fed, iii) starvation period before harvesting, iv) method of slaughter and v) storage time post mortem on fillet quality of 600g trout. The fillet fat content was examined and related to each of the five factors investigated in order to determine which had the most pronounced effect on fillet texture post mortem.

Texture measurements were undertaken using an Instron Universal Testing Machine and sensory analysis. Results indicated that fillet fat content could be increased 20% without affecting texture. Storage time post mortem was found to be the single most important factor affecting fillet texture. Sensory analyses verified the results obtained by instrumental texture testing.
Off-flavor problem in drinking water of Tokyo arising from the occurrence of musty odor in a downstream tributary
Authors: Hosaka Mitsugu , Murata Kiyoko , Iikura Yutaka , Oshimi Akiko , Udagawa Tomio
Published: May 2018

The Misato Purification Plant, Waterworks Bureau of Tokyo Metropolitan Government, in 1992 encountered an off-flavor problem due to the formation of 2-methylisoborneol (MIB) in a small tributary. This tributary had become polluted by rapid urbanization of the basin. However, it is situated at a point lower than the Plant and does not discharge directly into the main river. MIB produced in the downstream tributary was transported by a back current and via a Conveyance Pipe to the main river. The causative blue-green algae in the tributary water was determined through chemical and biological analysis of field samples as well as cultured materials. MIB production by one species of Oscillatoria isolated from the field samples was demonstrated. The strong MIB production potential of this species was also shown by a comparison of MIB production per unit length of trichome (16 pg/500μm) between this and other species reported previously. It was found that the presence of only one filament of this species in 1 ml of water could result in MIB levels above the threshold concentration of MIB for Japanese people. Results of this study revealed the importance of monitoring causative organisms and hydraulic conditions in tributary rivers.
Taste and odor events in Barcelona's water supply
Authors: Ventura F. , Matia L. , Romero J. , Boleda MaR. , Martí I. , Martín J.
Published: May 2018

Two cases of taste and odor episodes in raw and groundwater in the Barcelona (NE Spain) metropolitan area are described. The first was caused by creosote, a distill of coal tar, dumped into river water by two wood-preserving factories. The second taste and odor episode was caused by the presence of a potent odorous compound, the 2-ethyl-5,5-dimethyl-1,3-dioxane, in different groundwater samples. This compound is a by-product present in wastes from resin manufacturing plants that use neopentyl glycol as a raw material for acid-catalysed condensations.
The determination of compounds causing fishy/swampy odors in drinking water supplies
Authors: Khiari D. , Suffet I. H. , Barrett S. E.
Published: May 2018

Two chemical isolation methods, closed-loop stripping analysis (CLSA) and simultaneous distillation/extraction (SDE) in combination with gas chromatography/mass spectroscopy (GC/MS) and two sensory methods, flavor profile analysis (FPA) and sensory GC analysis, were used to determine the compounds responsible for the fishy/swampy odors in potable water. Samples were collected during four different fishy/swampy odor episodes and analyzed. It was determined that the compounds should be extracted by the SDE method. The SDE method extracts more polar compounds than the CLSA method. The main compounds identified were two unsaturated aldehydes (trans,trans-2-4-heptadienal and trans,4-heptenal). A ketone (1-penten-3-one) was tentatively identified.
Monitoring of groundwater in Gabal el Asfar wastewater irrigated area (Greater Cairo)
Authors: Rashed M. , Awad S. R. , Salam M. A. , Smidt E.
Published: May 2018

In arid to semi-arid countries water scarcity on a national level is seemingly contradicted by the local occurrence of sometimes large amounts of domestic wastewater. Consequently, in many countries this wastewater is considered as an additional source of water, particularly for irrigation purposes. The government of Egypt is planning to use wastewater in land reclamation in many areas on the Eastern and Western fringes of the Nile Valley and Delta.

A preliminary survey on the effects of wastewater irrigation was carried out by the Research Institute for Groundwater (RIGW) in the Gabal el Asfar area (Greater Cairo) in 1990-1991. A general framework of reuse of sewage effluent for irrigation in Egypt was discussed. The hydrogeological setting of the Gabal el Asfar area, the groundwater flow system and the thickness of the unsaturated zone were described. The impact on groundwater quality from sewage effluent irrigation has been assessed and the migration of pollution was evaluated.

The main objective of the present study is to analyze and explain changes in groundwater quality between 1991 and 1994. The study is executed within the framework of the Environmental Management Groundwater Resources project.
Flavour and off-flavour in wild and farmed atlantic salmon from locations around northern ireland
Authors: Farmer L. J. , McConnell J. M. , Hagan T. D. J. , Harper D. B.
Published: May 2018

Sensory profiling techniques were used to investigate the odour and flavour of Atlantic salmon (Salmo salar) from six sources in order to determine (i) whether there was any scientific basis for reports of off-flavours in salmon from certain sources and (ii) whether farmed and wild salmon differed in terms of flavour attributes. There were no consistent differences in odour or flavour between sea-caught wild salmon and farmed salmon. However, river-caught wild salmon showed enhanced ‘earthy’ flavour and odour; GC-odour assessment studies have indicated that 2-methylisoborneol and geosmin contribute to these attributes. For a short period, wild river salmon from one source also suffered from a manure-like off-flavour which has been shown to be due to the presence of skatole. The source of this compound remains uncertain.
Enhanced nutrient removal in high-rate ponds
Authors: Nurdogan Yakup , Oswald William J.
Published: May 2018

High-rate ponding (HRP) processes have evolved from conventional oxidation ponds and could play an important role in the treatment of organic wastewaters in sunbelt communities requiring tertiary treatment. HRP systems are very efficient in removing biochemical oxygen demand, nitrogen, and phosphorus. Mineralized nitrogen is removed by algal uptake of ammonium ion (NH4+) and out-gassing of ammonia (NH3). High daytime pH generated in the pond due to algal uptake of bicarbonate shifts the equilibrium in favor of NH3. There are also two mechanisms for phosphorus removal in an HRP; algal uptake and chemical precipitation. Phosphorus uptake by algae is lower than nitrogen uptake because the nitrogen content of algae is approximately ten times more than the phosphorus content, which is approximately one percent of the 100 to 300 mg/l algal dry weights in an HRP. If sewage contains 10 mg/l of phosphorus, algal phosphorus uptake would be only 1 to 3 mg/l. Precipitation of phosphates with polyvalent cations such as calcium and magnesium also occurs in a HRP due to the high pH. This precipitation is sometimes called “autoflocculation”, which is often incomplete due to insufficient calcium and magnesium concentrations in the wastewater. In the case of Richmond, California, where the studies were conducted, the sewage has low magnesium and very low calcium concentrations. Enhancement of calcium and magnesium deficient autoflocculation was studied by adding 20 to 80 mg/l of freshly slaked lime to the pond during the continuous paddle wheel mixing. This simple procedure improved phosphorus, nitrogen and algae removal efficiencies to a level greater than 90%.
Modelling biological treatability for meat processing effluent
Authors: Görgün E. , Ubay Çokgör E. , Orhon D. , Germirli F. , Artan N.
Published: May 2018

Biological treatability of major agro-industries wastewaters, such as meat processing effluents can only be evaluated with specific emphasis on slowly biodegradable substrate and using a multi-component modelling approach. This paper reviews the framework of the endogenous decay model and summarizes the necessary COD fractionation and the kinetic information to be incorporated in this model as applied to a meat processing effluent. Model interpretations of the respirometric experiments are used to define the fate of slowly biodegradable COD. Behavior of this wastewater in continuous activated sludge systems is studied by model simulations based upon experimental results.
Wastewater treatment by stabilization pond: Marrakesh experiment
Authors: Ouazzani N. , Bouhoum K. , Mandi L. , Bouarab L. , Habbari Kh. , Rafiq F. , Picot B. , Bontoux J. , Schwartzbrod J.
Published: May 2018

This paper presents results of two years of investigations on three types of wastewater stabilization pond treatment systems, purifying a raw urban wastewater, in the arid climate of Marrakesh. The systems tested were: two lined water hyacinth ponds, two lined facultative ponds and one anaerobic pond. During the course of the experiment, organic load, nutrients and parasitical load were studied. Results show that the macrophytic ponds were more efficient to reduce organic load (90% of TSS and 78% of COD) that the microphtic ponds; these ones were more efficient to eliminate nutrients (NTK 71%, NH4 60%, Ptotal 80% and PO4 62%). The anaerobic pond presents a lower efficiency, less than 40% for organic and less than 20% for nutrients. About sanitary concerns, all of the year, the macrophytic and microphytic pond effluents correspond to B category (WHO, 1989). The anaerobic pond yields B category effluent except in autumn when it corresponds to C category.
Technical economic analysis of stabilization ponds
Authors: Li Xian-wen
Published: May 2018

Employing stabilization pond systems to treat wastewater has the advantages of being economical of energy, easy to operate, and low in operation costs. However, stabilization pond systems have the problem of occupying large areas of land. Therefore, only after an overall technical economic analysis is made can an assessment be made of whether it is feasible to employ a stabilization pond systems to treat wastewater. During the period of the Seventh Five-year Plan of China, the “Study on the Technology of Stabilization Ponds” was set as one of the national scientific and technological key items. Seven experimental bases were established ranging from the north down to the south of China. With the great numbers of operational data obtained from both these bases and the existing stabilization pond systems, an analysis of the composition of the capital outlay in the stabilization pond system construction was made. The analysis shows that the land purchase cost accounts for approximately 60% of the capital outlay in construction and is the most important influencing factor. A comparison between the various costs of stabilization pond systems and those of conventional sewage treatment plant was made. Thereupon two new parameters were put forward: “equal capital land cost” and “upper limit of feasible land cost”. At the same time, a nationwide isogram of these two parameters was plotted. This isogram may be useful for preliminary design and planning purposes, and may be helpful to the users to assess comparatively easily whether its feasible to employ stabilization pond system.
The influence of pond geometry and configuration on facultative and maturation waste stabilisation pond performance and efficiency
Authors: Pearson H. W. , Mara D. D. , Arridge H. A.
Published: May 2018

Differences in length:breadth ratios (in the range of 1:1 to 6:1) and depths (from 1 to 2 m) had little effect on the performance and effluent quality (i.e. BOD, SS and FC) of secondary facultative ponds. Shallow maturation ponds (0.4 m) were more efficient at microbiological disinfection than deeper ones and could actually reduce land area requirements. KT values for faecal coliforms, salmonellae and rotavirus differed from one another in the same ponds and for different pond types. The Marais design equation for predicting faecal coliform numbers in pond effluents, although not perfect, does provide a reasonable design approach for systems containing more than two ponds in series.
Anaerobic-aerobic treatment of cheese wastewater with national technology in Mexico: The case of “El Sauz”
Authors: Monroy O. H. , Vázquez F. M. , Derramadero J. C. , Guyot J. P.
Published: May 2018

A low cost treatment alternative for cheese wastewater is discussed. The problem was to redesign three ponds which were operating below the consents. Discharge rate is 500 m3/day with a high organic load (2,750 kg COD/day). The new system consisted of: a grease trap, an anaerobic UASB type pond, an aerated pond and an effluent polishing pond with water hyacinth. Local technology was used except for the aeration equipment. The project was done at a low capital investment (US$ 330,000) and operational costs (US$ 0.55/m3) which were competitive with current market prices but within the official environmental consents.
Wastewater nutrient removal by marine microalgae cultured under ambient conditions in mini-ponds
Authors: Craggs Rupert J. , Smith Valerie J. , McAuley Paul J.
Published: May 2018

Two endemic strains of the marine microalgal species Phaeodactylum tricornutum (designated B2 and B4), previously isolated from a sewage outfall site in St Andrews Bay, Scotland, were cultured in 20-litre mini-ponds to determine their ability to remove ammonium and orthophosphate from wastewater diluted with seawater. These strains had been selected from 102 species for optimal nutrient removal and culture dominance in both batch and continuous culture on wastewater under controlled environmental conditions. Wastewater (primary sewage effluent) was diluted 1:1 with sterile seawater and continuously added to algal cultures grown in an open greenhouse under ambient conditions. Nutrient concentrations in the diluted wastewater and in outflow from the cultures were measured daily. Both strains remained unialgal with little change in biomass during the 14-day culture period and continuously removed >80% of ammonium from the wastewater. However, while strain B2 removed >80% of orthophosphate, there was a gradual accumulation of orthophosphate in the culture of strain B4. Measurement of nutrient concentrations in diluted wastewater and outflow from the continuous culture of strain B2 over 24 hours showed that at night nutrient removal dropped to a minimum of >70% for both ammonium and orthophosphate. These results indicate the potential value of strain B2 for use in scaled-up treatment ponds.
The pollution profile of alcohol distilleries treating beet sugar molasses
Authors: Eremektar G. , Tünay O. , Orhon D. , Gönenç E.
Published: May 2018

Fermentation of molasses and refining the produced alcohol by distillation is a common agroindustrial activity. The wastewaters originating from the process, especially the spent mash, are highly concentrated and contain TDS of over 50,000 mg/l as well as organic matter. Character of wastewaters varies with production application which affects the treatability characteristics. In this study four alcohol distillery plants treating beet sugar molasses are investigated to assess production applications and wastewater characteristics. Process profiles for three major modes of operation are prepared. Use of open steam and recycle of spent mash was calculated to affect the wastewater volume up to 25%. COD load is found to be practically unchanged with recycle while TDS increased significantly. Nature of COD and treatability characteristics are also expected to vary with recycle.
Efficiency of removal in stabilization ponds II. Statistical analysis of K values
Authors: Mendes B. S. , do Nascimento M. J. , Pereira M. I. , Bailey G. , Lapa N. , Morais J. , Oliveira J. S.
Published: May 2018

The analytical values obtained from five WSP systems located in different ecoclimatic zones in the centre and South of Portugal, were subjected to a statistical analysis of K and K20 values (as used in the van Hoff-Arrhenius equation) utilizing an analysis of variance and a vectorial analysis of principal components. Significant differences between K and K20 values in facultative, maturation ponds and in the whole system were verified. The projection of the first principal components of eigenvectors made possible the classification of the stations, showing the existence of similarities and discrepancies in their removal BOD kinetics behaviour. The K20 value must be estimated and taken into account for the design of waste stabilization ponds.