bluuebunny/crossref_metadata_2025 huggingface dataset:
Interactions between Free-Living Amoebae and Legionella in the Environment
Authors: Harf C. , Monteil H.
Published: May 2018

While their presence is common in the environment, culture and isolation of Legionella from environmental waters are fastidious. Free-living amoebae have identical aquatic habitats and are probable natural hosts for Legionella. In the laboratory it was shown that amoebae can feed on Legionella on solid and in liquid medium; both survived after several subcultures of amoebae. Amoebae were isolated from river waters and sediments. Cysts or trophozoites were subcultured; the amoebae were washed and harvested, then lysed by thermal shock and ultrasonic treatment. The lysates were positive for Legionella by IFD with different pools of antisera (A, B and C from CDC, Atlanta). Intra-peritoneal injection of the lysates in guinea-pigs allowed the isolation of L.pneumophila 1 from blood and various organs.

Amoebae are likely to be natural hosts for Legionella and are convenient as an ecological model in the laboratory. Intra-cellular replication and inclusion in resistant cysts of amoebae give them a possibility of survival in unfavourable conditions.
Correlations of the Protozoa, Cryptosporidium and Giardia, with Water Quality Variables in a Watershed
Authors: Rose Joan B. , Darbin Hamid , Gerba Charles P.
Published: May 2018

A watershed in the western United States was surveyed biweekly for a year for the protozoa Cryptosporidium and Giardia. Parasite samples were collected using filtration of 200-1000 L of water, eluted by washing the filter, concentrated and clarified with density gradients. Oocyst and cysts were detected using monoclonal antibodies, in a direct or indirect immunofluorescent assay. The organisms were enumerated on membrane filters using epi-fluorescent microscopy. Number of organisms per liter of water were then calculated. Grab samples were analyzed for total and fecal coliform concentrations as well as turbidities. After log10(y+1.0) transformations, Pearson's correlation coefficients were derived for each variable against all others.

From 39 samples, Cryptosporidium and Giardia were detected in 20 and 12 of the samples, respectively, and oocyst concentrations were approximately 10 times higher than cyst levels. The river downstream from the lake ran through an area concentrated with cattle pasture and had the greater numbers of both parasites (1.09 oocysts and 0.22 cysts/L). The lake, although receiving sewage effluents, may have also had lower levels (0.58 oocysts and 0.08 cysts/L) because of dilution and sedimentation.

Coliform levels ranged from 0.12 to 75 CFU/l00ml while fecal coliform levels were slightly lower. Turbidity averaged 55 NTU at the river and 48 NTU at the lake. Correlation coefficients were derived for all variables. Giardia concentrations were significantly correlated to Cryptosporidium concentrations with an r value of 0.778, significant at the 99% confidence level. No other correlations were observed between Giardia and total or fecal coliforms or turbidities nor between Cryptosporidium levels and total or fecal coliforms or turbidities.

Neither bacterial indicator organisms nor turbidity are reliable predictors for the absence of enteric protozoa in the study watershed.
Nitrogen-Fixing Heterotrophic Bacteria in Coastal Waters: A Comparison of the Contribution Made by Sewage Effluent in a Temperate and a Tropical Environment
Authors: Jones K. , Betaieb M.
Published: May 2018

Using identical techniques a comparison has been made between the distribution and survival of heterotrophic nitrogen-fixing bacteria from sewage in cold seawater of Morecambe Pay, UK, and warm seawater of Oahu, Hawaii, USA. In the colder seawater the predominant nitrogen-fixing bacteria are salinity-tolerant strains of Enterobacteriaceae (mainly klebsiellas) which come from sewage effluent discharged into the rivers and estuaries flowing into the bay. In the inshore warmer waters of Oahu, similar numbers of heterotrophic nitrogen-fixing bacteria are found but, although most are salinity-tolerant, they are not predominantly Enterobacteriaceae. Sewage effluent from Honolulu discharged into the sea is rapidly dispersed and the bacteria quickly killed by UV light which penetrates into the clear water. In Morecambe Bay, bacteria are found much further out to sea and they survive for much longer periods because sunshine levels are relatively low and light penetration is inhibited by high turbidity from suspended solids. Salinity-tolerance does not appear to have a high survival value for the nitrogen-fixing klebsiellas.
Inactivation of Hepatitis a Virus and Model Viruses in Water by Free Chlorine and Monochloramine
Authors: Sobsey Mark D. , Fuji Takashi , Shields Patricia A.
Published: May 2018

The kinetics and extent of inactivation of hepatitis A virus (HAV) as well as three other viruses, coxsackievirus B5 (CB5) and coliphages MS2 and ϕX174, by 0.5 mg/l free chlorine, pH 6-10, and 10 mg/l monochloramine, pH 8, at 5°C in 0.01 M phosphate buffer were determined. HAV wae relatively sensitive to 0.5 mg/l free chlorine but relatively resistant to 10 mg/l monochloramine. Compared to HAV, CB5 was quite resistant to inactivation by free chlorine but similar in resistance to inactivation by monochloramine. Inactivation of ϕX174 by free chlorine was rapid at pH 6-9 and intermediate between that of HAV and CB5 at pH 10. ϕX174 was inactivated most rapidly of all viruses tested by 10 mg/l monochloramine. Inactivation of MS2 by free chlorine was somewhat more rapid than HAV at low pH but less rapid than HAV at high pH. MS2 inactivation by 10 mg/l monochloramine was slowset of all viruses tested. These reeslts indicate that HAV is inactivated relatively rapidly by free chlorine but relatively slowly by monochloramine. Coliphage MS2 is a reasonable model to predict inactivation of HAV by free chlorine and inactivation of HAV and CB5 by monochloramine. It is a poor model for predicting free chlorine inactivation of CB5 and perhaps some other human enteric viruses.
The Approach to Sewage Treatment for the Coastal Towns of the Isle of Thanet, England
Authors: Midmer F. N. , Brown M. J.
Published: May 2018

The Isle of Thanet in South East England is an important holiday area with a total summer population of 180,000 in the four seaside towns of Birchington, Margate, Broadstairs and Ramsgate. Sewage is discharged to sea through short sea outfalls causing pollution of local beaches. The feasibility study into possible solutions showed that marine treatment is generally the most cost effective solution for coastal towns and that local solutions were cheaper than area solutions due to the significant impact of transfer costs.

The marine treatment schemes now being built provide preliminary treatment of fine screening and grit removal in enclosed headworks with high velocity, plug flow, operation of the outfalls. Special structures have been provided to protect the tapering manifold multi-port diffusers and to provide access to the outfalls. Installation of the outfalls was successfully achieved from difficult clifftop sites.
Biological Regeneration of Activated Carbon
Authors: Dobrevski I. , Zvezdova L.
Published: May 2018

This paper reports the results of investigations into the effect of activated carbon pore structure on the process of carbon regeneration. The suitability of several different commercial activated carbons for biological regeneration was investigated. The pore volume, pore radii, and surface area of the carbons were determined by mercury intrusion and BET methods. The adsorption capacities of the carbons were measured in completely mixed batch reactor systems. Heterogeneous micro-organism cultures and crude cell extract were used for bioregeneration of the carbons. The comparative adsorption and bioregeneration studies showed that there was no correlation between the original adsorption capacity and the regenerated adsorption capacity of activated carbons under the range of conditions used. This is due to the pore structure characteristics of the carbons. It has been found that the regenerated adsorption capacity depends on the volume of the pores with radii, r, of 5 - 50 nm (50 - 500 Å).

On the basis of substrate bio-oxidation reactions and the results obtained from identification of some exo-enzymes involved in this bio-oxidation process, the probable mechanism of bioregeneration is discussed.
Catalysed Formation of Chlorinated Organic Materials in Waters
Authors: Barnes D. , FitzGerald P. A. , Swan H. B.
Published: May 2018

Chlorinated organics and in particular trihalomethanes are generally considered to be toxic if ingested. Several factors such as precursors, pH, temperature and chlorine dose are known to affect the final concentration of these products. There is evidence of significant levels of trihalomethanes in intensively used recreational waters when chlorinated. Ingestion of 50 mL of water is postulated for swimmers. Copper, which is frequently used as an algaeide catalyses trihalomethane formation. At a copper concentration of 1 mg/L, in the presence of 1:1 ratios of humic acid: chlorine, 74% as much chloroform was produced in 24 hours at 2 mg/L of humic acid and 3.7 times as much at 10 mg/L than in the absence of copper. In addition, water used for recreational purposes will have increased precursor concentrations. These factors in the formation of chlorinated organic materials could restrict the intensive use of some water bodies, especially where some or all of the water is destined for potable use.
Factors Influencing the Bacteriological Quality of Spa-Pool Waters in New South Wales (Australia)
Authors: Bernard A. G.
Published: May 2018

The increasing popularity in the use of spa pools during the 1970's and 1980's and the accompanying incidents of folliculitis and ear infections caused by Pseudomonas aeruginosa associated with spa-pool use has necessitated the development of bacteriological and chemical guidelines for spa-pool water quality. The New South Wales (N.S.W.) Department of Health introduced a bacteriological standard for swimming pools and spa-pools in 1981 based on the findings of a series of surveys aimed at identifying the principal factors influencing the bacteriological quality of spa waters. Four surveys are summarised in this paper. The major findings described are the tenfold higher recovery of P. aeruginosa from spa-pools than from outdoor pools; the need for at least 2.0 milligrams per litre (mg/L) free chlorine residual in order to achieve reliable satisfactory water quality in spas compared with a requirement of 1.0mg/L to achieve the same quality in outdoor pools; the need to maintain pH below 8.0 in order to ensure efficient chlorine disinfection; the apparent inability of bromochlorodimethylhydantoin to adequately disinfect spas during heavy bather load periods; and the success of the Health Department's spa-pool operator education program which resulted in a 30% reduction in the incidence of bacteriologically unsatisfactory spa-pool waters in N.S.W. between 1980 and 1986.
Indigenous Coliphages and RNA-F-Specific Coliphages Associated with Suspended Solids in the Activated Sludge Process
Authors: Ketratanakul Awrapin , Ohgaki Shinichiro
Published: May 2018

The occurrence of indigenous coliphages and RNA-F-specific coliphages associated with suspended solids in the activated sludge process was investigated using E. coli K-12,F+(A/λ) as the host strain. Indigenous coliphages and RNA-F-specific coliphages adsorbed to suspended solids were detected in significant numbers in raw sewage. The adsorbed phages ranged from 12% to 30% of the total Indigenous coliphages in the raw sewage. Of these adsorbed phages, 6% to 20% were RNA-F-specific coliphages. Over 97% of the coliphages in the aeration tank were associated with suspended solids and most of these were RNA-F-specific coliphages,
Removal Efficiencies of Indicator Micro-Organisms in Sewage Treatment Plants
Authors: Omura T. , Onuma M. , Aizawa J. , Umita T. , Yagi T.
Published: May 2018

The removal of coliform bacteria, enterococcus bacteria, and coliphages in two sewage treatment plants, one using the activated sludge process and the other using a high-rate trickling filter, was investigated over a period of one year. Coliform and enterococcus bacteria were removed with equal efficiency by the two plants, but coliphages were removed more efficiently by the activated sludge process. Experiments on the mechanism of removal revealed that it was mainly due to adsorption on the activated sludge and on the slime in the trickling filter. Die-off of the micro-organisms seemed to play a minor role in the reduction in counts. The treated sewage was disinfected by chlorination prior to discharge into the receiving water. No coliforms were detected in the chlorinated effluents when they had chlorine residuals in the range of 0 to 1.521 mg/l. However, enterococci were detected when chlorine residuals dropped below 0.598 mg/l. Coliphages proved to be the most resistant organisms and they were generally detected throughout the range of chlorine residuals encountered.
Application of Gene Probes to Virus Detection in Water
Authors: Gerba Charles P. , Margolin Aaron B. , Hewlett Martinez J.
Published: May 2018

Gene probes offer a rapid and sensitive method for the detection of viruses in water and other environmental samples. Gene probes are small strands of nucleic acid labeled with radioactive or nonradioactive compounds for their detection. The target organism is identified by the hybridization of the probe to the organism's nucleic acid. Nucleic acid probes are at least 1000-fold more sensitive than serological tests such as enzyme-linked-immunoassay and do not first require cultivation of the virus for detection. Gene probes have been developed for organisms that do not grow in cell culture, and probes have been constructed for most of the major groups of enteric viruses. Gene probes have been applied to the detection of enteric viruses in water, marine sediment and shellfish. Radioactively labeled probes can detect as little as 1-10 infectious units of virus within 48 hours. A current disadvantage of probes is that they cannot determine the infectivity of the viruses; however, they can be used to quickly determine the growth of viruses in cell culture. Further development of nonradioactive probes should place virus detection capabilities into the hands of most water quality laboratories.
Water Consumption Patterns among Individuals in Cape Town
Authors: Bourne D. E. , Bourne Lesley T.
Published: May 2018

Liquid consumption patterns among individuals in Cape Town, South Africa, were ascertained. Two dietary surveys, one in summer and the other in winter, (n=1445 and 1393 persons) were carried out using a 24-hour recall of all food and drink items consumed. Total water consumption was calculated by using food composition tables. Water consumption was categorised by source: domestic tap water, water added in commercial processing, and water naturally bound in food. Mean total consumption was 1770 ml/head.day. Only 52% of the water consumed came from the tap at home. Water consumption was also classified by source from solid and liquid foods. 20.5% of total liquid is derived from solid foods.
Direct Solid-Liquid Separation Using Hollow Fiber Membrane in an Activated Sludge Aeration Tank
Authors: Yamamoto Kazuo , Hiasa Masami , Mahmood Talat , Matsuo Tomonori
Published: May 2018

Direct membrane separation using hollow fibers was applied to wastewater treatment in an activated sludge process. A membrane module with a pore size of 0.1 micron was immersed in the aeration tank and treated water was filtered through the membrane by suction. Various operational modes were applied to investigate stable flux conditions as well as organic and nitrogen removal. The stable treatment with a detention time of 4 hours could be kept for about 120 days at a volumetric organic loading of 1.5 kg COD/(m3 day) using intermittent suction with a low pressure of 13 kPa (1.3 m as water head). The COD removal was higher than 95% and more than 90% of COD supplied was oxidized to keep MLSS almost constant in the reactor without sludge wastage, which suggests that total oxidation of influent biodegradable materials can be achieved in this system. Up to 60% of nitrogen could be denitrified by intermittent aeration. The critical organic loading was estimated as 3 to 4 kg COD/(m3 day) in order to keep both stable flux and aerobic condition. The clogging in the membrane was inevitable to some extent, however, the intermittent suction and low pressure operation without cleaning could prevent the unrecoverable clogging and dead end of operation.
Patterns of Hydrogen in Biogas from the Anaerobic Digestion of Milk-Sugars
Authors: Mosey F. E. , Fernandes X. A.
Published: May 2018

Concentrations of hydrogen (1-1000 vpm) in the biogas from a laboratory-scale anaerobic digester, fed with (70 g/l) reconstituted skimmed milk as substrate, were intensively monitored to determine whether hydrogen could provide a useful new alarm/loading indicator for the anaerobic digestion process. With fast-fermenting substrates such as milk-sugars it proved to be a very sensitive event-marker, producing small ripples in time with operation of the digester feed pump as well as larger pulses caused by chloroform toxicity. Scavenging of hydrogen by lithotropic methanogens appeared to promote the fermentation of sugars directly to acetate, bypassing both the formation and subsequent breakdown of higher acids, a feature that is likely to prove peculiar to methanogenic and sulphate-reducing fermentations.
Kraft Lignin Behaviour in Diffused Aeration of Kraft Effluents
Authors: Larrea L. , Forster C. F. , Melé D.
Published: May 2018

Diffused aeration experiments carried out using a Kraft black liquor in batch reactors at 21±1ΩC were performed in order to characterize the relative importance of the mechanisms of chemical oxidation and condensation of lignin structures upon COD, lignin and colour removal and also to evaluate the influence of agitation intensity on these mechanisms. It was found that total COD decreased with time. This behaviour was independent of the aeration intensity and the reduction reached a value of about 18% of the initial COD after approximately 15 days. This reduction was attributed to chemical oxidation of some functional groups of the Kraft lignin contained in the substrate. However, filterable lignin (as absorbance at 272 nm) and colour (as absorbance at 465 nm) were not affected by chemical oxidation. It was also observed that agitation produced the formation of suspended solids by condensation of lignin structures. This took place during the first 2 days and provoked a reduction of filterable COD, lignin and colour which was dependent on the aeration intensity.
Biological Removal of Sulphate from Industrial Effluents and Concomitant Production of Sulphur
Authors: Maree J. P. , Hill E.
Published: May 2018

Sulphate wastes, such as sulphate-rich industrial effluents or waste gypsum, present a serious environmental pollution problem. A biological sulphate removal process has been evaluated for the treatment of these wastes. In this process, sulphate is converted to H2S when a carbon source, such as molasses is added. A complete mix reactor was used for sulphate reduction to H2S, which was subsequently stripped off in a closed system with either CO2 or nitrogen as carrier gas. The H2S in turn is oxidized to elemental sulphur in the sulphur production stage when it is brought into contact with a ferric solution. In a subsequent aerobic stage, degradation of organic carbon residuals and calcium carbonate crystallization are achieved simultaneously. Strontium, which is present in waste gypsum, is removed partially in the anaerobic stage, and completely in the aerobic stage. It is shown that sulphate wastes can be treated by the biological sulphate process for the production of reusable water and/or the recovery of valuable by-products such as elemental sulphur, sodium bisulphide and heavy metals.
The Concept of Soluble Residual Product Formation in the Modelling of Activated Sludge
Authors: Orhon D. , Artan N. , Cimşit Y.
Published: May 2018

The soluble effluent COD of a well operated activated sludge plant is likely to be composed almost entirely of organic matter generated by microbial activity. There is evidence to show that a significant portion of this soluble organic matter is non-degradable and may be due to similar microbial mechanisms. A model for the formation of these soluble residual products, (SRP), is propose'd, relating the SRP formation to the hydrolysis of non-viable cellular materials in the reactor. The set of equations describing the model are successfully calibrated and verified for a set of representative experimental data derived from Sequencing Batch Reactors. The model is found to explain and predict COD accumulation at the end of each cycle of these activated sludge systems.
Attrition Propensity of Activated Carbon in Relation to Particle Shape and Surface Texture
Authors: van Vliet B. M. , Young B. D. , Vennekens M.
Published: May 2018

Abrasion studies on a granular water treatment activated carbon were performed in a Couette flow apparatus. The abrasion rate is shown to be rapid initially and then to taper off. The particle surface roughness and shape of the activated carbon at various stages of abrasion were investigated using fractal analysis and by determining the circular shape factor. This was done using a digital image analyser. The results quantified the extent to which the external particle surface became less rough at a micro scale, and its shape more rounded as abrasion progresses. The kinetics of adsorption onto abraded and unabraded carbon was also investigated using a mini-column adsorption technique. Abrasion was shown to have no discernible effect on the mass transfer coefficient within the range of attrition levels considered.
The Use of Anoxic Selectors for the Control of Low F/M Activated Sludge Bulking
Authors: Shao Y.-J. , Jenkins David
Published: May 2018

Laboratory and pilot plant experiments on anoxic selector activated sludge systems were conducted on two wastewaters in some cases supplemented with nitrate, acetate or glucose. To prevent bulking sufficient anoxic selector detention time and nitrate levels must be available to reduce selector effluent soluble COD to below 100 mg/l and to reduce readily metabolizable organic matter to virtually zero (< 1 mg/l).

Soluble COD/NO3-N removal stoichiometry is in the range 6.0-6.7. Selector systems have elevated soluble substrate removal and denitrification rates compared to CSTR systems. These rates are not affected greatly by temperature (20-25°C) for CSTR sludges but are for selector sludges. Upon exhaustion of nitrate in a selector soluble COD leaks out of the activated sludge in significant amounts.

Thiothrix sp. and type 021N denitrify only to NO2 and at much slower rates than Zoogloearamigera does to N2. A sequencing batch system provides an optimistic estimate of the SVI that can be obtained by an anoxic selector system.
Substrate Affinity of Oligotrophic Bacteria in Biofilm Reactors
Authors: Nakamura K. , Shibata M. , Miyaji Y.
Published: May 2018

Several biofilm reactors were operated to investigate the substrate affinity of oligotrophic bacteria in the biofilm reactor. The attached oligotrophs were removed from reactors, and substrate affinity was determined in dispersed form. The saturation constant (Ks) of attached oligotrophs for acetate was less than 10 µg-C/l. The apparent Ks (Ksa) values of reactors were also determined to evaluate the performance of reactors,and the effect of specific surface area of packed media on Ksa was investigated at a loading of 0.006 mg-C per cm3-apparent media volume per hour. Larger specific surface area led to smaller Ksa, and 6.9 µg-C/l of Ksa for acetate was obtained with the media having 340 cm2 -surface area per cm -apparent media volume of specific surface area. The bacterial flora in the oligotrophic biofilm was examined, and Pseudomonas was found to be dominant.
Modelling of the Simultaneous Removal of Organic Substances and Nitrogen in a Biofilm
Authors: Chen G. H. , Ozaki H. , Terashima Y.
Published: May 2018

A mathematical model of the simultaneous removal of organic substances and nitrogen compounds in a biofilm reactor was developed, taking account of the relationships between oxidation, nitrification, denitrification, and mass transport. The model consists of a set of simultaneous mass balance equations for organic substances, ammonium nitrogen, oxidized nitrogen, oxygen, and alkalinity within the biofilm, and another set of transport equations for these substances within diffusion layer of the biofilm. Synthetic dual and triple Monod-type kinetics describing, respectively, oxidation, and nitrification and denitrification were incorporated into the mass balance equations. The model was evaluated based on experimental data and the computer simulations. This model successfully explained the mechanism of simultaneous removal and the effects of bulk concentrations of organic substances, DO, ammonium nitrogen, and alkalinity on simultaneous removal in a submerged biofilm reactor.
River Quality Models for Consent Setting in England and Wales
Authors: Crockett C. P. , Crabtree R. W. , Cluckie I. D.
Published: May 2018

In England and Wales the placing of effluent discharge consents within a statistical framework has led to the development of a new hybrid type of river quality model. Such catchment scale consent models have a stochastic component for the generation of model inputs and a deterministic component to route them through the river system. This paper reviews and compares the existing approaches for consent modelling used by various Water Authorities. A number of possible future developments are suggested including the potential need for a national approach to the review and setting of long term consents.
Heuristic Algorithms for Waste Load Allocation in a River Basin
Authors: Joshi Vijay , Modak Prasad
Published: May 2018

Waste load allocation for rivers has been a topic of growing interest. Dynamic programming based algorithms are particularly attractive in this context and are widely reported in the literature. Codes developed for dynamic programming are however complex, require substantial computer resources and importantly do not allow interactions of the user. Further, there is always resistance to utilizing mathematical programming based algorithms for practical applications. There has been therefore always a gap between theory and practice in systems analysis in water quality management. This paper presents various heuristic algorithms to bridge this gap with supporting comparisons with dynamic programming based algorithms. These heuristics make a good use of the insight gained in the system's behaviour through experience, a process akin to the one adopted by field personnel and therefore can readily be understood by a user familiar with the system. Also they allow user preferences in decision making via on-line interaction. Experience has shown that these heuristics are indeed well founded and compare very favourably with the sophisticated dynamic programming algorithms. Two examples have been included which demonstrate such a success of the heuristic algorithms.
Water Quality Indices for the Management of Surface Water Quality
Authors: House M. A. , Newsome D. H.
Published: May 2018

The need for a simple, objective and reproducible numeric scale to represent water quality in terms that all types of user will accept has been apparent for the last twenty years. Subjective classifications of water quality have been made, but they are seldom reproducible and lack sensitivity.

Now, a new family of water quality indices has been developed that can be used either independently or in combination which promise to overcome previous criticisms. They are currently being used by a UK water authority to assess their utility to personnel responsible for both the planning and day-to-day management of surface water quality.
A Critical Look into the Deviation of Full Scale Performance from Design Expectations
Authors: Zaloum R.
Published: May 2018

Deviations from design expectations appear to stem from views which assume that a unique response should result from a given set of operating conditions. The results of this study showed that two systems operating at equal organic loads or F/M ratios and at the same SRT do not necessarily give equal responses. This deviation was linked to the manner in which the HRT and influent COD are manipulated to obtain a constant or uniform load, and to subtle interactions between influent COD, HRT and SRT on the biomass and effluent responses. Increases of up to 200% in influent COD from one steady level to the next did not significantly influence the effluent VSS concentration while an effect on filtered COD was observed for increases as low as 20%. Effluent TKN and filtered COD correlated strongly with the operating MLVSS while phosphorus residual depended on the operating SRT and the organic load removed. These results point to the inadequacy of traditional models to predict effluent quality and point to the need to consider these effects when developing simulation techniques or computer assisted expert systems for the control of waste treatment plants.
Marine Treatment
Authors: Paul P. N. , Midmer F. N.
Published: May 2018

The marine treatment of sewage has become a well established practice in the UK. The technique involves the discharge of sewage through a system of ports or diffusers at a carefully chosen location (often several, kilometers out to sea) which will ensure that the subsequent dilution and dispersion of the sewage will achieve the required water quality objectives. The paper describes the studies and investigations that are carried out to determine the most appropriate discharge location and discusses the design of the pipeline and diffuser systems. The various construction techniques used in the UK to date are described, as well as the pre-treatment equipment and the methods of monitoring outfall performance. Particular attention is drawn to the need to undertake marine biological base-line surveys prior to commissioning as well as regular surveys after commissioning, both to ensure the environmental objectives are being met and to monitor the effects of the discharge.
Water Resources of the Danube River Basin; Sources of Pollution and Control and Protection Measures
Authors: Miloradov Milorad
Published: May 2018

This paper discusses the basic characteristics of the water resources of the Danube River basin, including the contributions of the territories of the individual states to the discharge volume of the river. The paper further outlines the major sources of pollution and the trends of various water quality parameters (e.g., BOD5 and nitrates) at the profile of the Danube flowing into Yugoslavia. Finally, the main protection and control measures necessary to safeguard the waters of the Danube River basin from degradation are discussed.
The Long Term Investigation of the River Danube Water Quality in the Yugoslav Section According to Microbiological Parameters
Authors: Gajin S. , Gantar M. , Matavulj M. , Petrović O.
Published: May 2018

The results of investigations of Danube river water quality in the Yugoslav section in the period from 1975 to 1988 are presented. The estimation of water quality was based on the numbers of heterotrophs, T/H ratio, and enzymatic activity. In addition, the number of bacteria of some physiological groups was determined. The results indicate that there was a deterioration of water quality in the investigated period. The number of heterotrophs was observably lower in the period from 1975 to 1978 than it has been in recent years. The constant worsening of the water quality is also evident from the the T/H ratio and enzymatic activity measurements.
Long-Term and Seasonal Aspects of the Water Quality of the River Danube within the Region of Vienna (Austria)
Authors: Ludwig Ch , Ranner H. , Kavka G. , Kohi W. , Humpesch U.
Published: May 2018

Data on water quality variables from 1968 to 1987 are analyzed statistically. The long-terra changes of five selected variables for the section of the River Danube at Vienna are investigated at four different sampling sites, two upstream and two downstream from Vienna. The influence of the efforts made to reduce wastewater inputs within the catchment area at Vienna were examined. Another objective was to obtain information about seasonal fluctuations at one selected sampling site. The quality of the data set is discussed with regard to the practical applicability of the results and suggestions are given for data collection.
Qualitative and Quantitative Analyses of Heavy Metals in the Danube at the Profile Situated at the Village of Vinča, Yugoslavia
Authors: Marjanović A.
Published: May 2018

Qualitative analyses of water from the River Danube were conducted to determine changes in the concentrations of heavy metals during the period 1985 to 1987. The samples were collected from a locality situated on the right bank of the river at the village of Vinča. The heavy metals Pb, Cd, Zn, Cu, Fe, Mn, As, Ni, and Hg were found to be constantly present in the river water, whereas Cr3+ and Cr6+ were not detected. It was found that the tendency for levels of these heavy metals to increase had ceased. The number of samples containing major ecotoxic elements (Pb, Cd, and Hg) was reduced, and a slight improvement was also recorded with regard to the other heavy metals, with the exception of Zn.
Automatic Warning Stations, Recent Serious Industrial River Pollution Incidents, and Prediction Models of Pollutants Propagation–Some European Examples
Authors: Mousty Paul , Morvan Jean-Paul , Grimaud André
Published: May 2018

The automatic analysing station located just downstream of the Basel urban area at Huningue, consists of an alarm station linking the automatic detection of certain important pollution parameters (T.O.C., hydrocarbons, heavy metals, pesticides, etc.). and the resulting alarms, to a working mathematical model of pollutant plume propagation, operating on the river between Basel and Strasbourg. This model is keyed to the real flow conditions of the Rhine, determined by life-size tracing operations (using coloured Rhodamine marker). A decisive factor in speeding up the transmission of alarm signals, this system allows, among other things, optimum management of the valves and locks communicating with the Rhine, in order to avoid the penetration of the pollutants into the ramifications of the hydrographic network feeding the groundwater table in Alsace.

The alarm station put into service on the Rhine can look back on 10 years experience in the struggle against accidental pollutions which primarily occurred in the Paris area. There, an important alarm network consisting of eight automatic analysing stations was set up on the rivers Seine, Marne and Oise to protect the most important drinking water supply of France which provides water to more than 4 million inhabitants.
Urban Development in the Danubian Basin and Its Effects on Water Quality–Aspects and Trends
Authors: Vujnovič R.
Published: May 2018

The fate and future of urbanisation in the Danubian Basin is linked to the processes of urban agglomerations in Europe and it can be expected that increased urban concentrations will develop along the Danube and its main tributaries, just as other regional urban systems develop in Europe.

The natural potential of the Danubian Basin is limited from the point of view of future agglomerations. The main limitations come from the availability of natural water resources, and further, from the limited space for specific uses.

The deterioration of water quality by pollution may additionally restrict the limits of urbanisation; improvement or deterioration of the situation would depend on the location and character of the sources of pollution.

The idea that urban development in the Danubian Basin must be jointly planned by all Danubian countries (in the form of a water master plan or a physical plan of the Basin) becomes increasingly appreciated. The general objective of the plans would be to make the best use of the available space and natural resources of the Danube and tributaries, for the benefit of the people living in the Basin.
Biological Treatment of Soya Bean Waste
Authors: Tay Joo-Hwa
Published: May 2018

Soya bean beverages and “Tofu” are the major sources of protein in the Asian diet. Wastewater from soya bean food processing plant consisted of high concentration of BOD5, COD, nitrogen and phosphorus. The wastewater should be pre-treated before discharging into the sewer or watercourses. Activated sludge process was an effective biological treatment process for soya bean wastewater. Up to 95% of BOD5 can be removed by activated sludge orocess. The removal of nitrogen and phosphorus were 67% and 57% respectively. The treatment efficiency increased with higher mean cell residence time. The settleability of activated sludge was good, and suspended solids removal efficiency was well above 90%. The biological kinetic coefficients were also determined from the pilot study.
A Modified UASB Process Treating Winery Wastewater
Authors: Cheng S. S. , Lay J. J. , Wei Y. T. , Wu M. H. , Roam G. D. , Chang T. C.
Published: May 2018

During the last two years,twenty-seven bioreactors of upflow anaerobic sludge blanket(UASB) process were constructed and operated well to treat 3,300 m3/day of winery wastewater in six winery plants in Taiwan. Each UASB reactor was installed with an internal filter and a side-armed sludge settler to separate gas-liquid-solid effectively in 127 m3 of reactor volume.These six plants established good performance of UASB process with different organic loadings depending on different characteristics of the winery wastewater. Start-up performance of the modified UASB process in four winery plants was investigated.Bioactivity of anaerobic sludge in each UASB was evaluated by means of Biochemical Methane Potential (BMP)test. Biokinetics of Monod and Haldane models were employed to interpret the different sludge characteristics in terms of gas production rate. Scanning electronic microscopy also showed different morphology of sludge granules in three UASB systems.
Effect of Short-Term Temperature Increase on the Performance of a Mesophilic UASB Reactor
Authors: van Lier J. B. , Rintala J. , Sanz Martin J. L. , Lettinga G.
Published: May 2018

A study was carried out to assess the effects of short-term temperature increments on the treatment efficiency and methane production of UASB reactors at a working temperature of 37-39°C. Two different substrates were used to determine the effects on the several bacterial groups involved in the digestion process. One reactor was fed with defined synthetic acidified wastewater the other with unacidified wastewaler from a distillery process. Shocks of 5-24 hrs were applied at temperatures in the range of 45 to 61°C. Up to 45°C no detrimental effects were noticeable. Higher temperatures led to a sharp decrease of the activity of the different microbial populations as a result of elevated decay rates. Propionate oxidation turned out to be the most sensitive for temperature increments, whereas the acidogenic bacteria were least affected. Temperature shocks of 55 and 61°C led to a decrease of 50% of the overall efficiency after 10 and 3 hrs, respectively. By means of batch experiments decay rates of 0.44 and > 10 hr −1 of the methanogenic bacteria were estimated at 55 and 65°C respectively. As temporary inactivation of the mesophilic bacteria during a temperature shock was found to be unlikely, reactor recovery is dependent on the bacterial growth and the biomass retention capacity of the reactor. When unacidified wastewater is treated, a pH decrease has to be considered during a temperature shock.
Reduction in Environmental Pollution Caused by Waste Waters from Edible Oil Refineries, Concept and Investigations
Authors: Rohbrecht-Buck K. , Sekoulov I.
Published: May 2018

In the refining of edible oil highly concentrated flows of various waste waters, particularly acidic water, are produced. The mixing of these waste waters with other flows that are only slightly contaminated will be prohibited in West Germany in future. Moreover, the legislation will demand biological treatment of the waste waters extending beyond the chemicophysical wastewater purification hitherto employed. A concept is presented for a process for purifying the waste waters produced in the refining of edible oil whose essential innovative element is a two-stage aerobic biological treatment with a discontinuous activated sludge process in the first stage, and a submerged fixed bed reactor in the second stage. The combination of processes was tested in pilot trials, which show that maximum elimination of the relevant waste water constituents can be achieved in this way. COD inlet concentrations of around 3000 mg/l have been reduced to residual contents of approx. 200 mg/l, and fats and easily degradable carbon compounds (BOD5) have been almost completely removed from the waste water. The biological treatment requires prior neutralisation and cooling of the wastewaters to 20 to 30°C, the controlled addition of nitrogen, and careful monitoring and control of the operation of the plant.
Large-Scale Sewage Sludge Composting: A Case for Maintaining a Diversified Program
Authors: Toffey William E.
Published: May 2018

The Philadelphia Water Department operates the world's largest sewage sludge composting plant – the Sludge Processing and Distribution Center (SPDC). This $80 million plant handles anaerobically digested sewage sludge generated by three regional sewage treatment plants treating 530 million gallons (2,000 million liters) of wastewater daily. SPDC was designed to compost sludge solids in an aerated static pile system of composting. During 1989, the SPDC composted the full 60,000 dry tons (56,000 dry metric tons) of sludge solids it received for processing. The Department has chosen, however, to not compost all incoming sludge solids in the future, but instead to maintain a diversified sludge utilization program. Five reasons have contributed to this decision:SPDC's practicable composting capacity is about two-fifths of its designed capacity.Facility managers have been compelled to consider limiting compost production as a key odor control strategy.Commercial markets for sludge compost have not grown in a one-to-one proportion to the increased production capacity at SPDC.Programs to use or dispose of uncomposted sludge solids are implementable and cost effective.Reliance on any single technology or end use is unacceptably risky.

The planned distribution of sludge products for calendar year 1990, by proportion of total solids and by product weight, consists of: 1) marketing of screened compost (33%), 36,000 metric tons; 2) stripmine reclamation with a cake/compost mix (20%), 45,000 metric tons; 3) landfill disposal of sludge cake (17%), 64,000 metric tons; 4) agricultural use of compost (15%), 40,000 metric tons; 5) agricultural use of sludge cake (10%), 27,000 metric tons; 6) land reclamation use of compost (3%), 10,000 metric tons; and 7) local application of compost (2%), 5,000 metric tons.
Evaluation of Municipal Sludge Drying and Dewatering with Respect to Sludge Volume Reduction
Authors: Smollen Maryla
Published: May 2018

A number of parameters that influence sludge dewatering behaviour have been identified, but there is a lack of consensus which of these are of the greatest concern in sludge treatment strategies. Moisture retention characteristics were obtained from vacuum drying of centrifuged sludge samples to subdivide moisture into immobilised, physically and chemically bound fractions. Physically bound moisture is responsible for unsatisfactory dewatering by centrifugation. Polyelectrolyte releases some of the immobilised water, but simultaneously increases the physically bound moisture content which gives rise to large energy inputs during mechanical dewatering.

Commonly used dewaterability measurements do not appear to be linked to moisture retention characteristics.
Sustained Shockwave Plasma (SSP) Destruction of Sewage Sludge – A Rapid Oxidation Process
Authors: Mathiesen M. M.
Published: May 2018

Sewage sludge is destroyed and neutralized in an environmentally safe way by rapid, plasma-assisted oxidation. The material is rendered inert where it is being produced, leaving behind a benign and useful solid oxidation byproduct and producing a clean off-gas. The solid product can be used as a cement or aggregate. The process is based on oxidation enhancement by employment of sustained Shockwave plasma and controlled oxidation to provide an off-gas which can effectively be handled by gas cleaning systems to provide a degree of purity required by the most stringent air quality standards. The process is very compact, owing to very rapid throughput and near-stoichiometric air requirements. It is entirely enclosed.

The Neutrail SSP process comprises three main steps; drying, oxidation and gas cleaning. The oxidation step consists of three distinct sections. It is designed to completely destroy all organic structures, limit acid gas formation and to retain a maximum amount of all volatile heavy metals in the solid residue in a non-leachable form, thereby making it possible to devise a gas cleaning system which can deliver a clean off-gas economically.
Tentative Nitrogen Removal with Fixed Bed Processes in Malmö Sewage Treatment Plant
Authors: Andersson B.
Published: May 2018

A test program for the use of fixed bed processes in systems for nitrogen removal at an advanced sewage treatment plant is described. Results from studies on nitrification in a full scale trickling filter plant with different filter depths and at different wastewater temperatures are presented. Results from full scale experiments with denitrification/nitrification in a retrofitted activated sludge plant are also presented. The effect of an aerated submerged fixed bed in the aeration basin on nitrification was investigated. Observations of the biofilm formed on the fixed bed were made in microscope.
Scaling Prodedure for Biofilm Processes
Authors: Manem J. A. , Rittmann B. E.
Published: May 2018

This paper presents a scaling procedure for biofilm processes based on three critical parameters derived from mechanistic models and used as similitude criteria. The advantage of using similitude criteria is that the prototype and scaled processes can have the same performance (e.g., effluent concentration) when the similitude criteria are made equal, even though all the mechanistic parameters are not known and the full kinetic models have not been solved.

This scaling procedure, limited to situations for which the same microorganisms and process type can be assumed, is based on waking equal the three similitude criteria needed in biofilm kinetics: (1) blofilm surface concentration, ϕ1, (2) blofilm shear loss-rate, ϕ2, and (3)mass balance, ϕ3. The three similitude criteria are necessary to give, for the prototype and scaled processes, the same flux Into the blofilm (ϕ1), the same accumulation of blofilm (ϕ2), and the same mass balance on the substrate (ϕ3). When all three criteria are equal, both processes give the same effluent quality. One key finding of the similitude procedure is that the influent concentration, So, cannot remain constant if all three similitude criteria are to be equal simultaneously. The need to alter so is most important when external mass transport resistance and blofilm shear loss are significant. It is only when external mass transport resistance or biofilm shearing is unimportant that similitude can occur with the same so in both processes

This procedure was succesfully applied to scale-down of the nitrification filter of the Croissy water treatment plant (France) for laboratory studies.