bluuebunny/crossref_metadata_2025 huggingface dataset:
Feed management and reduction of aquaculture wastes
Authors: Kolsäter L.
Published: May 2018

Proper feed management is based on precise prediction of fish growth and good knowledge of the dynamics in the relationship between feeding (SFR), growth (SGR) and feed conversion (FCR). Recent research at Laxforsen indicates that there is a relationship between SFR, SGR and FCR at any water temperature, fish size and at any level of digestible energy in the feed. The investigation clearly shows that there is a target area rather than a point for optimum feeding. Optimized local feed management together with further development of fish feed in terms of increased digestibility of feed components will lead to greater profitability to the farmer and also minimize aquaculture wastes.
Seawater quality at industrial effluents discharge zone
Authors: Al-Muzaini S. , Beg M. U. , Al-Mutairi M. , Al-Mullalhah A.
Published: May 2018

Shuaiba Industrial Area (SIA) accommodates 38 plants, of which 15 are located in the eastern sector and the other 23 in the western sector. The factories, being near the shore of the Arabian Gulf, discharge their wastewater directly into the Gulf after in-plant treatment.

How far industrial effluents influence the marine environment was assessed using Microtox toxicity assays of seawater samples collected twice a week for six months from two stations located upstream and downstream of SIA.

Out of 50 samples each collected from Station No 1 and Station No 2, only two samples from the former showed toxicity, whereas at the latter site ten samples showed medium to high levels of toxicity. The higher incidence of toxicity in the downstream area may be due to the mixing of effluent from individual discharges and indicate some inefficiency of the effluent treatment process. The study revealed that the biological assay provides effective assessment of water quality.
Depuration of oil taint and muscle pigment from fish
Authors: Davis H. K.
Published: May 2018

Fish in the vicinity of large oil spills acquire characteristic flavour taints but little is known about their subsequent depuration. In this study, trout were exposed to 3 different tainting treatments with diesel fuel, then transferred to clean water, and samples assessed for taint at intervals for up to 15 weeks. The observed depuration periods were 2 to 17 times longer than others have reported but less than was needed for some of the farmed salmon affected by the Braer oil spill. Comparison of taint depuration times with changes in flesh pigmentation showed that flesh colour cannot be used to predict clearance of taint.
Characterization of odorous compounds from bleached kraft pulp mill effluent
Authors: Brownlee B. G. , Kenefick S. L. , MacInnis G. A. , Hrudey S. E.
Published: May 2018

Odour compounds in extracts of bleached kraft pulp mill effluent (BKME) have been characterized by olfactory gas chromatography (OGC) and gas chromatography-mass spectrometry. A variety of sulfury odours was detected by OGC in addition to woody and pulp mill-like odours. Three sulfur compounds were identified by comparison of retention times and partial mass spectra with authentic standards: dimethyl disulfide, 3-methylthiophene and thioanisole (methyl phenyl sulfide). Typical concentrations in BKME were 1, 0.05, and 0.5 μg/l, respectively. Their odour intensity is relatively low and they were not detected by OGC. Dimethyl trisulfide was tentatively identified by comparison of its partial mass spectrum with a literature (library) spectrum. Its concentration in BKME was estimated at 0.5-2 μg/l. It corresponded to a skunky odour in the OGC profiles. Efforts to identify another odour peak, eluting just after 3-methylthiophene, with a pronounced alkyl sulfide odour were unsuccessful.
Geosmin and 2-methylisoborneol production in a major aqueduct system
Authors: Izaguirre G. , Taylor W. D.
Published: May 2018

The California Aqueduct supplies water from Northern California to Southern California, dividing into the West and East branches above Pyramid Lake. In July and August 1990, elevated geosmin levels (10-48 ng/l) occurred in the East Branch of the aqueduct, which extends along the southern edge of the Mojave Desert. The geosmin episode was associated with attached algal growths on the sides of the aqueduct. A geosmin-producing cyanobacterium, possibly a Microcoleus sp., was isolated from both water and periphyton. In the summer of 1991, elevated levels of 2-methylisoborneol (MIB) occurred in the East Branch of the aqueduct (up to 78 ng/l), along with lower levels of geosmin. In July 1992, a recurrence of MIB production led to a severe off-flavor problem for a water agency that receives water directly from the aqueduct, resulting in numerous complaints from consumers. In both episodes, a Lyngbya sp. was isolated from periphyton and mud collected near the water's edge. These isolates were strong MIB producers in culture, yielding 240 and 260 μg/l, respectively. Beginning in 1992, a second, relatively weak MIB producer, a Hyella sp., was isolated from membrane-filter plates inoculated with aqueduct water. These off-flavor episodes - associated with low flows during a drought period - showed that previously untainted water sources can be affected by these problems when conditions change.
Drinking water off-flavour caused by the formation of short-chain fatty acids in slow sand filters
Authors: Karlsson S. , Grimvall A. , Borén H.
Published: May 2018

A case study carried out at a municipal drinking water treatment plant in southern Sweden showed that the formation of short-chain fatty acids in slow sand filters can result in severe off-flavour problems. When an extract of the headspace of the surface layer of a sand filter was subjected to gas chromatographic analysis with sensory detection (GC sniffing), several strong, rancid odours were detected. Mass spectrometric analysis of the same extract, before and after methylation, showed that substantial amounts of butyric acid, valeric acid and isovaleric acid were present in the analysed sample. The off-flavour caused by these compounds was removed by repeated shock chlorination of the malfunctioning slow sand filter. Analysis of fatty acid esters may provide an early warning of the described off-flavour problem.
Extraction and identification of chemicals causing grassy odors in flavor profile analysis (FPA) reference standards
Authors: Khiari D. , Suffet I. H. , Barrett S. E.
Published: May 2018

The extraction and identification of natural fresh grass odor standard was studied. Fresh grass was allowed to sit in water until it released its grassy components to the water. The resulting grassy samples were analyzed and the chemicals responsible for the characteristic odors identified by Flavor Profile Analysis and sensory GC analysis. Closed-Loop Stripping Analysis was used for the isolation of volatile non-polar compounds and Simultaneous Distillation Extraction was used for the isolation of more polar chemicals of moderate volatility. A primary grassy odor standard (cis-3-hexenyl acetate) and a secondary grassy odor standard (cis-3-hexen-1-ol) were identified by Mass Spectroscopy and Sensory GC. Dose-Response curves were plotted and corresponding odor threshold concentrations (OTC) were determined for the cis-3-hexen-1-ol the cis-3-hexenyl acetate. It was found that cis-3-hexenyl acetate was approximately 50 times more odorous than the cis-3-hexen-1-ol. The OTC of cis-3-hexenyl acetate was found to be between 1 and 2 μg/l.
The influence of growth conditions on odor-compound production by two chrysophytes and two cyanobacteria
Authors: Rashash D. M. C. , Dietrich A. M. , Hoehn R. C. , Parker B. C.
Published: May 2018

The influence of several environmental factors (e.g., light intensity, temperature, nitrogen, and phosphorus) on population density and odor-compound production of two chrysophytes, Synura petersenii and Dinobryon cylindricum; and two cyanobacteria, Anabaena laxa and Phormidium calcicola was investigated. The odors associated with each alga were evaluated by flavor profile analysis (FPA) at several intervals during their initial culturing in defined media. Algal cell and media extracts were analyzed individually by capillary gas chromatography-mass spectrometry (GC-MS). Both cyanobacteria produced geosmin (“earthy” and “corn” odors); however, the P. calcicola also produced relatively large amounts of MIB (“musty-earthy” odors). Both chrysophyte cultures contained 2t,4c,7c-decatrienal (“fishy” odor); and in addition, 2t,6c-nonadienal (“cucumber” odor) was isolated from the S. petersenii.

Young cultures of Anabaena laxa (e.g., <20 days) retained most of the geosmin produced. Throughout its population growth, more than 80 percent of the MIB and geosmin produced by P. calcicola was detected in the media rather than in the cells. Synura petersenii,produced more 2t,4c,7c-decatrienal than 2t,6c-nonadienal and retained nearly 90 percent of both compounds throughout the algal population growth. Dinobryon cylindricum produced 2t,4c,7c-decatrienal, and, like the S. petersenii, retained most of the compound. Greater production of the compounds by the two chrysophytes was apparently associated with log-phase growth rather than specific environmental conditions; extended log-phase growth (and prolonged production of compounds) was observed in the S. petersenii culture during the low-temperature treatment.
Release of geosmin by Anabaena circinalis following treatment with aluminium sulphate
Authors: Velzeboer R. , Drikas M. , Donati C. , Burch M. , Steffensen D.
Published: May 2018

Taste and odour due to algae are not generally removed during conventional water treatment and can sometimes be increased during the treatment process owing to cell lysis. Some reasons for this have been documented in the literature but there appears to be contradictory evidence regarding the effect of flocculation. In this study the effect of aluminium sulphate on cultured cells of Anabaena circinalis was evaluated at concentrations and conditions that would occur in a water treatment plant. Aluminium sulphate did not appear to cause lysis of cells of cultured Anabaena circinalis nor increase the amount of geosmin in the water. Flocculation under laboratory conditions, which simulated operating water treatment plants, resulted in removal of cells in a healthy state, with no additional release of geosmin.
Bench-scale determination of the removal of odour compounds with biological treatment
Authors: Huck P. M. , Kenefick S. L. , Hrudey S. E. , Zhang S.
Published: May 2018

A bench-scale bioreactor was designed to determine the parameters required for kinetic modelling of assimilable organic carbon (AOC) removal. This reactor was then used to attempt to determine the kinetic parameters in modelling the removal of two odorous compounds, (geosmin and 2,4,6-trichloroanisole) with biological treatment. The bench-scale bioreactor column had a volume of 56 ml, contained 2540 × 3 mm glass beads, and was operated at a feed rate (Q) of at least 2.0 ml/min with a recycle rate (Qr) of 50-70 ml/min. At these rates the bioreactor can be regarded as a continuous stirred tank reactor (CSTR). The biofilm was established using filtered river water blended with an acetate solution and was maintained with an inorganic nutrient and buffer solution. A synthetic water containing geosmin and 2,4,6-trichloroanisole (2,4,6-TCA) was fed to the column after the biofilm had reached steady state. Influent concentrations and effluent concentrations were monitored using extraction with a closed-loop stripping apparatus (CLSA) and analyses using gas chromatography-mass spectrometry (GC-MS). The bioreactor did not effectively remove the taste and odour compounds being studied and these poor removals prevented determination of kinetic parameters. A bioreactor which is not acclimated and which receives an organic and hydraulic loading in the range normally experienced by rapid filters and granular activated carbon (GAC) contactors could not be recommended as a primary treatment process for the removal of these taste and odour compounds.
Odour and flavour in waters: quantitative method for a new european standard
Authors: Rigal S.
Published: May 2018

In the majority of the European Community, the assessment of odours and flavours in water supplies are carried out only by sensory analysis. Consequently it is essential for institutes and water companies to use the most accurate method in evaluating odour and flavour in drinking water. Until recently, most of the European countries had their own method or national Standard. Due to the requirements for odour and flavour in EC Directive 80/778 on drinking water quality, applicable throughout Europe, there was a need to standardise their method of evaluation. At the time, no ISO Standard for flavour and odour existed. Moreover, since the materials intended for contact with drinking water must not induce organoleptic problems, manufacturers of pipes, fittings and coatings are also concerned in a standardization. This paper presents the state of the art for flavour and odour evaluation in European countries and the next European Standard for these parameters. The Standard will be based on the dilution method to obtain a threshold flavour number (TFN) and a threshold odour number (TON) of a water. The principle is to compare the successive dilutions of water samples with a reference water. Several methods can be used, for example paired and triangle test, forced and unforced choice. The Standard also includes the selection, training and calibration of panellists. This Standard was elaborated within the scope of CEN/TC 230 “Water Analysis”, and was achieved through the active participation of experts from water institutes, water companies and manufacturers of materials.
Development of a taste and odor expert system: present state, strengths, limitations and possible future evolution
Authors: Bruchet A. , Anselme C. , Jammes C. , Mallevialle J.
Published: May 2018

This paper summarizes the development of an expert system designed to help solve taste and odor problems in drinking waters which cannot be attributed to typical odorous compounds such as geosmin or 2-methylisoborneol (MIB), but rather to complex mixtures of volatiles usually detected below their individual odor thresholds. Long-term studies at four different sites were carried out to create a data base including flavor profile analysis (FPA) and closed-loop stripping-gas chromatography (CLSA-GC-FID) data. Examination of the data using factorial correspondence analysis allowed us to establish statistical links between odor descriptors and specific volatile organics. A stochastic regression model was also built which permits estimation of a sample flavor profile from its chromatographic content. The strengths, limitations and possible future developments of this method are discussed in detail.
A simple design and operation for the anaerobic treatment of highly concentrated swine waste in the tropics
Authors: Yang P. Y. , Kuroshima M.
Published: May 2018

In order to develop a simple operation for an anaerobic treatment process for highly concentrated pig wastewater for small producers, a three-stage anaerobic treatment process was investigated. The system provided a series of mixing, homogenization, biological reaction and final stabilization of concentrated pig waste (total solid content of 8–10%). The process provided a stable operational performance, simple operational procedure and well stabilized sludge effluent. It was also found that the system is economically feasible in Hawaii. Compared to the other treatment processes for highly concentrated pig waste, this process is considered as an appropriate alternative for the application of the small producers in land limited and tropical conditions. Also, the present treatment system can be easily developed into a prefabricated package plant which can minimize the on-site labor and building costs.
Efficiency of removal in stabilization ponds I. Influence of climate
Authors: Mendes Benilde S. , do Nascimento M. Jenny , Pereira M. Irene , Bailey Gerard , Lapa Nuno , Morais João , Oliveira J. Santos
Published: May 2018

Owing to the existing or predictable water deficiencies in the South of Portugal, it is necessary to carry out the appropriate management of water resources, by reducing and/or minimizing the negative impacts of untreated/treated domestic effluents in the aquatic environment. As Portugal has a great diversity of ecoclimatic areas, five different stabilization pond systems were chosen to carry out a control study during one year (from March 1991 to March 1992). According to Pina Manique & Albuquerque the ecological classification of these stations is different, varying from Ibero-mediterranean (continental) up to mediterranean (maritime). The physical and chemical parameters studied were: temperature, pH, dissolved oxygen, conductivity, BOD, COD, nitrates, nitrites, ammonia and total nitrogen, total suspended and volatile solids, total phosphorus and orthophosphates. The microbiological parameters studied were: total and faecal coliforms, faecal Streptococci, Clostridium perfringens and Pseudomonas aeruginosa. The correlations between climatic parameters and the efficiency of the removal of organic matter were analysed.
Rotavirus removal in experimental waste stabilization pond systems with different geometries and configurations
Authors: Oragui J. I. , Arridge H. , Mara D. D. , Pearson H. W. , Silva S. A.
Published: May 2018

Rotavirus removal in waste stabilization ponds is a relatively slow process: in a series of ten ponds (a 1-d anaerobic pond followed by nine 2-d ponds) its numbers were reduced from 1.4 × 105 per litre to zero, and in an “innovative” series (a 1-day anaerobic pond, 3-d facultative pond, 3.8-d, 3-d and 5-d maturation ponds) from 5.1 × 104 per litre to <5 per litre. Faecal coliforms were better indicators of rotaviruses than was Clostridium perfringens .
Optimization of flocculation/flotation in chemical wastewater treatment
Authors: Ødegaard Hallvard
Published: May 2018

An experimental investigation on flocculation/flotation for direct chemical treatment of municipal wastewater was carried out. It was demonstrated that flocculation units prior to flotation must be designed and operated differently to those used prior to sedimentation. Recommendations regarding design criteria both for the flocculation unit and the flotation unit are given.
DAF treatment of a reservoir water supply: comparison with in-line direct filtration and control of organic matter
Authors: Schmidt P. D. , Tobiason J. E. , Edzwald J. K. , Dunn H.
Published: May 2018

The goal of this paper is to compare the performance of an in-line direct filtration (no flocculation) process with a dissolved air flotation (DAF) and filtration process for drinking water treatment. Both processes were studied at the pilot scale and included biologically active dual media (GAC/sand) rapid filters. Specific attention is given to the fate of organic matter. Organic matter was analyzed by measurements of dissolved organic carbon (DOC), assimilable organic carbon (AOC), disinfection by-product formation potential (DBPFP) and ultraviolet absorbance at 254 nm (UV254). In general, flotation removed a large fraction of organic matter with additional removal provided by biologically active filters. Most of the work occurred with ozonation of the raw water (pre-ozone). Ozone increased the biologically assimilable fraction of the water; filtration decreased this fraction to acceptable levels. Overall, effects of ozone on other organics are relatively small.
Use of dissolved air flotation in potable water treatment in Finland
Authors: Heinänen J. , Jokela P. , Ala-Peijari T.
Published: May 2018

The basic concepts of treating humic waters with dissolved air flotation are discussed emphasizing the important role of zeta potential in the forming of floc-air-bubble-agglomerates. Then practical experiences from Finnish drinking water treatment plants are presented. When surface water is used as a raw water, it is more or less humic. Thirty-six such plants have dissolved air flotation as a clarification process, the oldest one dating from 1965. They serve about one million people. All of them are working well proving that dissolved air flotation is a suitable method in humic water treatment. Some special cases are discussed in detail. These are cases where sufficient data about design, operation and costs are available and which it is hoped can help other designers. The last plant referred to is an example of an advanced treatment process where dissolved air flotation is an integrated unit process.
Primary-secondary flotation of three municipal wastewaters: pilot-scale study
Authors: Krofta M. , Miskovic D. , Burgess D.
Published: May 2018

A pilot system containing a particularly designed configuration of primary flotation unit and a combined flotation-filtration clarifier, was used for advanced municipal wastewater treatment.

The system which was investigated demonstrated the feasibility of municipal wastewater treatment by the flotation separation of fluid and coagulated-flocculated solids (Total suspended solids (TSS), organic load, Phosphorous (P), Total Kjeldahl Nitrogen (TKN)) without using microbiological oxidation.

The particular objective herein was to create a preliminary approach to theoretical evaluation of positive pilot-study results in the form of two kinetic models.

Based on positive pilot results, and kinetic analysis, the following conclusions were reached:A double-stage flotation/filtration system might be a viable alternative for municipal wastewater treatment.Empirical models and prediction developed here reflect the kinetics of the removal of coagulated and flocculated solids by flotation.
Recent applications of dissolved air flotation pilot studies and full scale design
Authors: Arnold Steven R. , Grubb Thomas P. , Harvey Peter J.
Published: May 2018

The use of Dissolved Air Flotation (DAF) as a solids/liquid separation process in water treatment has been an effective alternative to sedimentation for 70 years. The process was initially applied for removal of materials which had a specific gravity less than water, such as fats, oils, fibers, and grease. DAF installations expanded in the late 1960s to wastewater and potable water treatment. Today, Dissolved Air Flotation is utilized for a wide variety of water and wastewater applications. DAF is applied extensively for wastewater sludge thickening and it is widely accepted in Scandinavia and the United Kingdom for potable water treatment. It has also gained a foothold in the United States with the start up of a 7.5 mgd (28.4 Ml/d) potable water flotation plant at New Castle, New York. The goal of this paper is to present recent applications of Dissolved Air Flotation technology on a variety of raw water sources. Descriptions and general design parameters of a typical flotation and a proprietary combined flotation and filtration process will be discussed.
Applicability of the recreational water quality standard guidelines
Authors: Mariño F. J. , Martinez-Manzanares E. , Moriñigo M. A. , Borrego J. J.
Published: May 2018

The applicability of WHO/UNEP criteria and the EC bathing water directive as microbial water quality guidelines were examined by means of an epidemiological-microbiological study of two Mediterranean bathing beaches. Neither set of guidelines proved particularly successful for protecting the public from health hazards related to faecal contamination of bathing waters.
Risk of bacillus cereus and pseudomonas aeruginosa nosocomial infections in a burns centre: the microbiological monitoring of water supplies for a preventive strategy
Authors: Valentino L. , Torregrossa M. V.
Published: May 2018

Opportunist bacteria are a potentially very serious problem in hospital burns units, particularly where the quantity and quality of water supplies may not be reliable, and patients are especially vulnerable. A programme of routine microbiological monitoring is described which minimises the risk to patients.
Removal and inactivation of viruses by drinking water treatment processes under full scale conditions
Authors: Havelaar A. H. , van Olphen M. , Schijven J. F.
Published: May 2018

Risk-based evaluations of the hygienic quality of drinking water require accurate data on removal and inactivation of pathogens by different steps of the treatment chain. The continuing trend to reduce chemical disinfection leads to an increased interest in the effect of other processes, based on physical removal or biological inactivation. This study reports data on the removal and inactivation of entero- and reoviruses by three such processes. For comparison, data on a variety of model organisms are also reported. All studies were carried out in the winter period because the concentration of viruses is then at its maximum, and the reducing capacities of the processes are at their minima. Storage in three reservoirs in series (average detention time 7 months) reduced the concentration of enteroviruses by a factor of 400-1,000, river bank filtration was highly effective, reducing enteroviruses by a factor of at least 10,000. The effect of coagulation/flocculation/sedimentation/filtration processes was highly variable, and was better when rapid sand filtration was included. The removal of F-specific RNA bacteriophages most closely followed that of viruses in these three processes.
Strategic approaches to the development and implementation of water quality management plans
Authors: Brown S. A. P. , van Niekerk A. M.
Published: May 2018

Catchment water quality management plans are central to the Department of Water Affairs and Forestry's (DWAF) water quality management strategy. Catchment plans provide a coherent framework to ensure that fitness for use is achieved at catchment level.

This paper describes DWAF's perspective on and approach to key aspects associated with the development and implementation of catchment water quality management plans. It expands on the role and composition of a catchment water quality management plan; the guiding principles inherent to the development of a management plan; the key success factors ensuring implementability; key aspects associated with the development of the plan, public participation, project structure, water users and setting water quality objectives and various aspects in DWAF's approach for future consideration.
What's a river worth, anyway? A resource valuation survey of the Ohio river
Authors: Vicory A. H. , Stevenson A. K.
Published: May 2018

The Ohio River Valley Water Sanitation Commission (ORSANCO) is a government agency established in 1948 to control and abate pollution of the interstate waters of the Ohio River Valley. ORSANCO, represented by eight states of the Ohio Valley and the federal government, carries out water quality monitoring and assessment programmes, co-ordinates spill response activities, promulgates pollution control standards for the Ohio River, and co-ordinates the individual programmes of state and federal agencies. ORSANCO recognizes that public and political support are as important to effective river basin management as technical knowledge and activities. Because such support is so closely related to economic interests, ORSANCO and the National Park Service commissioned a survey project in May 1993 to compile readily available data to estimate the “value” of the Ohio River from several key standpoints. This information is intended to draw attention to the national significance of the Ohio River in its economic, cultural and natural resource dimensions, and to illustrate the magnitude of positive economic impacts to be realized by achieving water quality improvements. This project brought together for the first time information that will serve to enhance public and political awareness of the Ohio River Valley, and thus enhance support for aggressive environmental management.
Pathogen die-off in stored wastewater sludge
Authors: Gibbs R. A. , Hu C. J. , Ho G. E. , Phillips P. A. , Unkovich I.
Published: May 2018

The storage of wastewater sludge as a possible low-cost means of pathogen reduction prior to its beneficial reuse was examined. However, after a 12 month storage period levels of Salmonella, faecal coliforms and streptococci, and Giardia cysts were too high for simple storage to be considered an adequate treatment option.
Disinfection of effluents by combinations of chlorine dioxide and chlorine
Authors: Narkis N. , Katz A. , Orshansky F. , Kott Y. , Friedland Y.
Published: May 2018

The behaviour of both chlorine dioxide and chlorine, either as an individual or as combined disinfectants were studied on effluents from activated sludge. The results of the disinfection efficiency, residual disinfectants and their by-products, obtained by treating the same effluents at the same day with identical dosing sequence of chlorine dioxide and chlorine, alone and in a combined dosing, were compared after periods of the same contact. In most cases, it seems that each disinfectant maintains its individual capabilities when used in a combined manner. The combination produced a relatively stable high residual of both disinfectants. The important finding is the fact that the combinations of chlorine dioxide and chlorine decreased the concentration of the undesirable chlorite ion and increased the concentration of the newly formed chlorine dioxide. A greater advantage is obtained by using chlorine dioxide prior to chlorine. Therefore, combined disinfection in this sequence is recommended.
Investigation of injury of coliforms after chlorination
Authors: du Preez M. , Kfir R. , Coubrough P.
Published: May 2018

The extent of coliform injury after chlorination and the relationship between regrowth of injured coliforms and assimilable organic carbon concentrations (AOC) were studied. Seeded (Escherichia coli E25), sterilized tap water (AOC concentration adjusted to 400mg C/l) was incubated for a period of 3 weeks (25-28°C) after chlorination (0.5 and 1mg/l). Bacteria were enumerated using m-Endo agar LES and m-T7 agar. Chlorination resulted in a 3 log reduction in coliform counts within one minute. No viable colonies were found for 27% of the water samples enumerated with m-Endo agar LES. Injured coliforms were enumerated from all the water samples except one and were present in higher numbers than non-injured coliforms in the majority of the water samples. During the second and third weeks of incubation, only injured bacteria were observed in chlorinated samples. Additional AOC contributed little to the survival and regrowth of chlorinated bacteria.
The study of the environmental impact assessment process for water resources development in Taiwan
Authors: Chang S. P. , Wen C. G.
Published: May 2018

Since 1983, The R.O.C. government in Taiwan has actively promoted the environmental impact assessment (EIA) system. More than 15 EIAs of water resource development projects have been conducted. Up to December 1994, seven pieces of relevant legislation for water resources projects, including two laws (amendments) and five regulations, were completed. The government is pushing forward the legislation of EIAs. Basically, the EIA review will include the following written statements: an initial environmental examination (IEE), the draft of an EIA report and the EIA final report.
The interaction of silver ions and hydrogen peroxide in the inactivation of E. coli: a preliminary evaluation of a new long acting residual drinking water disinfectant
Authors: Pedahzur Rami , Lev Ovadia , Fattal Badri , Shuval Hillel I.
Published: May 2018

The inactivation efficiencies of silver ions, hydrogen peroxide and their combination was studied as part of a performance evaluation of the combined disinfectant for drinking water applications. The major advantages of such combined disinfectant include, low toxicity of its components, long lasting residual effect and low disinfection by product formation. Specific strains of E. coli (E. coli-B (SR-9) and E. coli K-12) were used in this study as target microorganisms and the separate and combined inactivation efficiencies of silver and hydrogen peroxide were evaluated at different concentrations and exposure durations. Both, silver and hydrogen peroxide exhibited a significant inactivation performance even at concentrations that do not pose any health risk according to the EEC, WHO and the USEPA (the USEPA Maximum Contaminant Level (MCL) of silver is 90 ppb, and currently, there is no MCL for hydrogen peroxide but it is approved as a food additive in the USA). Combinations of 1:1000 silver:hydrogen peroxide (w) exhibited higher inactivation performance as compared with each of the disinfectants alone and in some cases a synergistic effect was observed, i.e., the combined disinfectant exhibited higher inactivation performance than the sum of the inactivation levels of the separate disinfectants. Thus, for example, one hour exposure to 30 ppb silver, 30 ppm hydrogen peroxide and their combination yielded 2.87, 0.65 and 5 logs of inactivation respectively. While the rate of inactivation shown by this combined disinfectant, now available commercially in a stabilized formulation is relatively slow, it may well hold promise as a secondary disinfectant providing long lasting residuals and biofilm control required for distribution systems. Its disinfection action may be similar to chloramines, the use of which has been recently outlawed in France and in Germany and which are now under careful scrutiny in other countries due to the formation of undesirable by-products.
Chloramine-induced injury of enterotoxigenic escherichia coli
Authors: Tosa K. , Hirata T. , Taguchi K.
Published: May 2018

In order to determine the level of injury caused by chloramination, samples of the enterotoxigenic E. coli (O168) were exposed to mixtures of sodium hypochlorite and ammonium sulfate solutions. Injury levels are shown to be proportional to chloramine concentration.
Virucidal effect of UV light on hepatitis a virus in sea water: evaluation with cell culture and RT-PCR
Authors: Lévêque F. , Crance J. M. , Beril C. , Schwartzbrod L.
Published: May 2018

Virucidal effect of UV light on hepatitis A virus was investigated in artificial sea water. Infectious virus was no longer detectable after 15 min irradiation of 3 liter experimentally contaminated water. Genomic amplification by polymerase chain reaction after reverse transcription allowed the detection of viral RNA in all samples even after 60 min irradiation.
Broadening participation in integrated catchment management for sustainable water resources development
Authors: Maaren H. , Dent M.
Published: May 2018

The need to broaden participation and thereby democratise the process of integrated catchment management for sustainable water resources development is fundamental to peaceful, holistic and equitable progress in Southern Africa. This need is urgent in a region racked with conflict and riven by inequalities that exacerbate the already complex situation surrounding the sustainable development of scarce water resources.

The key questions, however, relate to the strategies which organisations can employ both internally and inter-organisationally to empower people to play a meaningful role in the processes that will lead to the attainment of these goals.

This paper explores the possibilities for such strategies and moves the discussion beyond purely scientific needs to examine the technological and human resources and cultural and organisational transformations which are taking place. It also suggests some transformations that are still required for such strategies to succeed.
Bacteriophage persistence in the sea environment
Authors: Lucena F. , Lasobras J. , Muñoz R. , Araujo R. , Jofre J.
Published: May 2018

Somatic coliphages, F-specific phages and phages infecting Bacteriodes fragilis were determined in: sea water at variable distances from the freshwater polluting foci, in mussels collected at sites with different levels of faecal pollution of overlaying waters and in mussels purchased in markets. The relative proportions of the different bacteriophages are similar to those in polluting freshwater both in waters and mussels collected in areas near the sites where polluted freshwater reaches the sea. However, as we move further from the origin of pollution there is a very significant increase in the relative proportion of somatic coliphages and particularly of phages infecting B. fragilis.
Stability of plasmid-borne resistance of antibiotics during starvation of Escherichia coli in raw and treated waste water and brackish water
Authors: Arturo-Schaan M. , Tamanai-Shacoori Z. , Cormier M.
Published: May 2018

Cell survival and plasmid stability in Escherichia coli containing plasmids RP1, R388 and pUB824 were studied in raw waste water, treated waste water, and brackish water. The Escherichia coli strain survived well in raw and treated waste water. However, in brackish water E. coli HB101 remained culturable throughout the microcosm study, with an overall drop of 2 log units in culturability from the start to the end of the experiment. The maintenance of the three plasmids was plasmid-, and environment-dependent. Plasmid pUB824 (4 kb) was stably maintained under all conditions used in the study. Maintenance of RP1 (56 kb) and R388 (33 kb) was markedly influenced by nutritive conditions, which caused a segregation of the plasmids from cells. The results of the present study demonstrate the influence of plasmid size on plasmid stability in natural waters.
Detection of F+ bacteriophage in large volumes of water by a membrane filter method (MFM)
Authors: Erb P. , Nasser A. M. , Fattal B.
Published: May 2018

In recent years, F+ bacteriophages were proposed by several researchers as an alternative to fecal coliforms to signal the presence of fecal pollution in water sources. The sample volume which can be monitored for the presence of bacteriophages by the conventional methods is limited to 1-10 ml. This study was conducted to test the feasibility of detecting and enumerating F+bacteriophages in large volumes of water by an MFM. A recovery of up to 100% was observed for MS2 coliphage when the pH of the water samples was adjusted to 3.5. The presence of humic acid in the water interfered with the adsorption of phages to the membrane filter. F+bacteriophages were detected in 11 out of 50(22%) water samples collected from swimming pools in Jerusalem. Total coliform were detected in only 2 out of the 50 (4%) samples. Both indicator microorganisms were detected in only one sample, suggesting the lack of correlation between their presence. The results of this study demonstrated that the MFM is a sensitive assay for detecting low concentrations of F+bacteriophages in large volumes of water.
Assessment of the success of the Peel-Harvey estuary system management strategy - a Western Australian attempt at integrated Catchment Management
Authors: Humphries Robert , Robinson Sally
Published: May 2018

The Peel-Harvey estuary and its catchment have been the subject of intensive investigation and management since the late 1970s, because of concern about worsening algal blooms and their associated impacts. After diagnosis of the problem, possible management options were assessed in the light of the available technical information, and a management strategy developed and implemented.

Various Integrated Catchment Management (ICM) approaches have been used, including voluntary reduction of fertilizer use, and the construction of a new channel to the ocean to achieve an appropriate socio-environmental solution. Innovative approaches were also taken in developing statutory and non-statutory management targets and land-use controls and guidelines. To date these measures appear to have been successful, although some of them are vulnerable in the long term.

This is currently the best Australian example of an ICM approach to the management of a complex environmental problem which has actually been implemented. It is also a good example on a world scale of addressing an environmental problem using a systems approach with an appropriate socio-environmental solution.
Estimation of the fate of microbial water quality contaminants in a South African river
Authors: Hohls D. , du Plessis G. , Venter S. N. , Steynberg M. C. , De Wet C. M. E. , Rodda N. , Kfir R.
Published: May 2018

The aim of this study was to evaluate the validity of assumptions, regarding assimilative capacity for microbial contaminants, implicit in microbial water quality management in South Africa. A one dimensional steady state stream water quality model, assuming first order decay of microbial water quality variables, was employed in an attempt to describe and predict microbial water quality in the chosen catchment. Based on the faecal coliform counts the results indicated that the processes of decay and dilution were inadequate to yield water quality which complied with South African and international guidelines for the domestic and recreational use of water. It was also found that a first order decay model can, with fairly limited data, allow a manager to investigate different microbial water quality scenarios in a cost-effective manner.
Use of gene probes for the detection of quiescent enteric bacteria in marine and fresh waters
Authors: Anderson Sally A. , Lewis Gillian D. , Pearson Michael N.
Published: May 2018

Specific gene probe detection methods that utilise a non-selective culturing step were tested for the ability to recognise the presence of quiescent enteric bacteria (Escherichia coli and Enterococcus faecalis ) within illuminated freshwater and seawater microcosms. An E. coli specific uidA gene probe and a 23S rRNA oligonucleotide probe for Enterococci were compared with recoveries using membrane filtration and incubation on selective media (mTEC and mE respectively). From these microcosm experiments a greater initial detection (from 4 hours to 1 day) of E. coli and Ent. faecalis using gene probe methods was observed. Additionally, a comparison of E. coli direct viable counts (DVC) in sunlight exposed microcosms with recoveries by selective media and gene probe methods revealed a large number of viable non-culturable cells. This suggests that enumeration of E. coli by a gene probe method is limited by the replication of the bacteria during the initial non-selective enrichment step. The detection of stressed Ent. faecalis by the oligonucleotide gene probe method was significantly greater than recovery on selective mE agar, indicating an Enterococci non-growth phase.
Microbial quality of a marine tidal pool
Authors: Genthe B. , Kfir R. , Franck M.
Published: May 2018

The microbial quality of a marine tidal pool on South Africa's Atlantic coast was found to be inferior to that of the adjoining seawater (the latter complying with various water quality guidelines, the tidal pool failing). This seems to be due to pollution from the bathers using the pool.
Viruses in river waters and sediments in Austria
Authors: Walter R. , Baumgartiger C. , Schwabl M.
Published: May 2018

Cytopathogenic viruses have been found in two Austrian rivers, in which hydroelectric power stations are being built or are already in existence. Very rarely viruses have been found in the sediments of these rivers, though the applied method yielded a virus recovery rate of 58%. In the aquifers viruses could be found only in one well. These results suggest a rather efficient selfpurifying capacity in both highly oxygenated rivers.
Quality control in environmental microbiology compared with chemistry: what is homogeneous and what is random?
Authors: Tillett Hilary E. , Lightfoot Nigel F.
Published: May 2018

Organism counts from environmental quality control (QC) samples, such as indicators in water, will show variation even if they come from a single well mixed batch. This is due to random variation and there may be additional effects from organism behaviour. Thus the samples are not homogeneous in their content. Samples for chemistry will also be variable in their content but this may be at a level below the limit of detection and thus the observed measurements will show apparent homogeneity.

Organism counts may take 24 hours to achieve and longer to confirm. A chemical result can often be obtained rapidly. Assessment of performance with microbiological counts usually requires the accumulation of evidence over several samples. A judgement can be attempted with each chemical QC result.

QC in environmental microbiology is an important and growing field. The apparent imprecision and slowness in assessing performance is unavoidable. Sound quality assurance programmes will accommodate these factors.
Cadmium and lead uptake from food by the fish Dicentrarchus Labrax
Authors: Odžak N. , Zvonaric Tomislav
Published: May 2018

Cadmium and lead uptake from the fish food in liver and muscle tissue of sea bass Dicentrarchus labrax were investigated experimentally. The conditions as close as possible to those in natural environment were ensured by this experiment. The sea bass was exposed to elevated concentrations of Cd (5.36, 38.5 and 485 mg kg−1) and Pb (2.58, 25.1 and 238 mg kg−1) in fish food. In fish exposed to these concentrations, a linear metal concentration increase (in liver and muscle tissue) was established during the experiment. However, liver and muscle tissue respond differently during metal uptake. Although at the end of the experiment (62 days) Cd concentration was much higher in the liver of exposed fish, bioaccumulation in the muscle tissue was faster. Quite an opposite trend was recorded for lead bioaccumulation. Bioaccumulation of Pb in the liver was faster than in muscle tissue. The results of this experiment confirmed that the liver, as a central organ of metabolic processes, may be a measure of an actual Cd and Pb load of an organism.
Waterborne disease incidences in the Mediterranean region as a function of microbial pollution and T90
Authors: Kocasoy G.
Published: May 2018

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

The purpose of the present study is to investigate the effect of the rate of pollution as well as of the microbial self purification capacity (T90) on public health.
Achieving simultaneous nitrification and denitrification of wastewaters at reduced cost
Authors: O'Neill Mike , Horan Nigel J.
Published: May 2018

The Orbal process for the treatment of waste waters, claims simultaneous nitrification and denitrification in the outer lane in the presence of a dissolved oxygen concentration of 1.5 mg/l. The potential of this process is to offer both a reduced cost and simplified operation for nitrogen removal in the Mediterranean environment. The objective of this work was to investigate these claims and attempt to describe a mechanism for the experimental verifications. Using mixed cultures grown in chemostats, simultaneous nitrification and denitrification was observed under oxic/anoxic cycling. A reduced pathway, or ‘nitrite shunt’ could not be demonstrated but it was possible to explain the observations based on the lag time of the denitrifiers under oxic conditions. Denitrification continued for some time before oxygen replaced nitrate as the terminal electron acceptor and the length of the lagged response was a function of the duration of the anoxic conditions.