bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of ozonation and chlorination on viability and infectivity of Cryptosporidium parvum oocysts
Authors: Hirata T. , Chikuma D. , Shimura A. , Hashimoto A. , Motoyama N. , Takahashi K. , Moniwa T. , Kaneko M. , Saito S. , Maede S.
Published: May 2018

Experimental studies on ozonation and chlorination were conducted to determine capacity for inactivating Cryptosporidium parvum oocysts in batch modes at pH 7, 20°C. In both experiments, the log reduction of animal infectivity was linear and clearly decreased as disinfectant CT product increased. However, the curve of reduction in viability determined by both in vitro excystation assay and DAPI/PI permeability assay exhibited a shoulder. The CT products of ozone per 1 log reduction in infectivity were 3 mg middot min/L for 0.5 mg/L and 1.5 mg · min/L for 0.3 mg/L, while viability determined by in vitro excystation was reduced by only 0.2 logs for the CT product of 3 mg · min/L. In the chlorination experiment, thereduction of animal infectivity was up to 3 logs for the CT product of 2,700 mg middot; min/L, while reduction of viability was smaller at 0.16 logs in in vitro excystation and 0.04 logs in DAPI/PI permeability (in PI exclusion) for the same CT product. The CT product of free chlorine per 1 log reduction in infectivity was estimated to be in the range of 800 to 900 mg · min/L.
Removal of Cryptosporidium by high rate contact filtration: the performance of the prospect water filtration plant during the Sydney water crisis
Authors: Mazounie P. , Bernazeau F. , Alla P.
Published: May 2018

In Sydney, Australia, during July, August and September 1998, three comprehensive boil water notices were issued in response to the detection of elevated concentrations of Giardia and Cryptosporidium in the water system. While the incidence of illness did not increase above background levels, the political impact of these events was sufficient to initiate a full-scale judicial inquiry. The treatment plants came under intense scrutiny, particularly the Prospect Water Filtration Plant, which provides for approximately 85% of Sydney's drinking water demand. As part of the investigation, detailed audits of the Prospect Plant were carried out and Cryptosporidium parvum seeding experiments were undertaken in a prototype plant in order to assess the removal capability of the Prospect filtration process. The overview of the Plant performance and the results of the Cryptosporidium seeding runs presented in this paper confirm that the Prospect Water Filtration Plant was achieving at least 3 logs pathogen removal prior to and during the contamination events.
Inactivation of Cryptosporidium parvum oocysts and other microbes in water and wastewater by electrochemically generated mixed oxidants
Authors: Casteel M. J. , Sobsey M. D. , Arrowood M. J.
Published: May 2018

Alternative disinfectants of water and wastewater are needed because conventional chlorination is ineffective against C. parvum oocysts. Reliable indicators of disinfection efficacy against C. parvum also are needed. Mixedoxidants (MO) electrochemically generated from brine were evaluated in batch disinfection experiments for inactivation of C. parvum oocysts and Cl. perfringensspores in both oxidant demand-free (ODF) water and treated wastewater. Coliphage MS2 and Escherichia coli B were also tested under some conditions. C. parvum oocyst infectivity was quantified by cell culture assay, and the dyes DAPI (4′,6-diamidino-2-phenylindole) and propidium iodide (PI) were used to assess oocyst viability in wastewater experiments. In treated wastewater dosed with 10–13 mg/L MO, inactivation after 90 minutes was about 3 log10 for C. parvum and about 2.5 log10 for Cl. perfringens spores; MS2 and E. coli were rapidly inactivated by > 5 log10. In ODF water, a 4 mg/L dose of MO inactivated ∼3 log10 of C. parvum oocysts and ∼1.5 log10 of Cl. perfringens spores. Inactivation of C. parvum oocysts and Cl. perfringensspores was less extensive at a lower MO dose of 2 mg/L. The use of DAPI and PI to determine viability of oocysts treated with MO did not correlate with, and greatly overestimated, cell culture infectivity. At practical doses and contact times, MO disinfection of water and wastewater achieves appreciable inactivation of both C. parvum oocysts and Cl. perfringens spores. Cl. perfringens spores reliably indicated oocyst inactivation by MO, but E. coli and coliphage MS2 were inactivated much too rapidly to indicate C. parvum inactivation.
Occurrence and separation of Cryptosporidium oocysts in drinking water treatment
Authors: Dolejš P. , Ditrich O. , Machula T. , Kalousková N. , Puzová G.
Published: May 2018

The presence of Cryptosporidium sp. in Czech drinking water sources was monitored. High numbers of Cryptosporidium oocysts were found in the Slezska Harta reservoir after 1997 summer floods. The influence of iron (III) coagulant dose, mixing conditions and preozonation on the removal efficiency of Cryptosporidium oocysts was studied. Low mixing intensity produced flocs with poor settling features. The efficiency of sedimentation expressed as residual iron after sedimentation was proportional to removal efficiency of oocysts. Both underdosing or overdosing of iron (III) coagulant resulted in decrease of COD, turbidity and oocyst removal. Preozonation positively influenced removal efficiency of oocysts in the conventional drinking water treatment train studied.
Enumeration of Cryptosporidium oocysts from surface water concentrates by laser-scanning cytometry
Authors: Zanelli F. , Compagnon B. , Joret J. C. , de Roubin M. R.
Published: May 2018

The utilization of the ChemScan® RDI was tested for different types of water concentrates. Concentrates were prepared by cartridge filtration or flocculation, and analysed either without purification, or after Immunomagnetic separation (IMS) or flotation on percoll-sucrose gradients. Theenumeration of the oocysts was subsequently performed using the ChemScan® RDI Cryptosporidium application. Enumeration by direct microscopic observation of the entire surface of the membrane was carried out as a control, and recoveries were calculated as a ratio between the ChemScan® RDI result and the result obtained with direct microscopic enumeration.

The Chemscan enumeration technique proved reliable, with recoveries yielding close to 100% in most cases (average 125%, range from 86 to 467%) for all the concentration/purification techniques tested. The quality of the antibodies was shown to be critical, with antibodies from some suppliers yielding recoveries a low as 10% in some cases. This difficulty could, however, be overcome by the utilization of the antibody provided by Chemunex.

These data conclusively prove that laser scanning cytometry, which greatly facilitates the microscopic enumeration of Cryptosporidium oocysts from water samples and decreases the time of observation by four to six times, can be successfully applied to water concentrates prepared from a variety of concentration/purification techniques.
Sludge management – future issues and trends
Authors: Campbell H. W.
Published: May 2018

A review of the literature over the last thirty years shows that while the diversity of unit processes for sludge treatment has increased dramatically, there are still only three basic ultimate disposal routes for processed sludge; land application, landfill and incineration. None of these end-uses are fundamentally either good or bad; each one is simply more or less appropriate for a given situation. Selection of a sludge management option is not immune to popular trends and this may introduce artificial criteria as opposed to having the choice based on a critical evaluation of the needs of each specific project.We must ensure that efforts to promote one approach to sludge management does not inadvertently create new obstacles for alternative solutions. For example, landapplication of sludge is enjoying a well-deserved period of growth based on good science, cleaner sludges and proactive public education. However, we must not fall into the trap of assuming that this is the only “good” approach and discounting other potential solutions without a unbiased assessment. This paper summarizes the major trends in sludge management from the perspective of both the past and the present. Issuesrelated to current practice and future developments are discussed with reference as to how they may impact on future sludge management decisions. Sludge management alternatives should be selected based on consideration of the following elements: multiple use options provide the producer with flexibility to respond to changing priorities, the solution must reflect the unique needs of the individual community and the public must be incorporated into the decision making process from the very beginning.
Effect of surfactant on alum sludge conditioning and dewaterability
Authors: Ruhsing Pan J. , Huang C. , Gang Fu C.
Published: May 2018

Sludge disposal has become a new challenge for the Taiwan government due to the increasing demand for better quality and greater quantity of water. In some water treatment plants, surfactant has been applied in the flotation process to improve its performance, which suggests the use of surfactant in sludge conditioning. In this study, effects of surfactants on the conditioning of the alum sludge collected from Feng-Yuan Water Treatment Plant were investigated. Surfactants of various charges, namely CTAB and SDS, were added to sludge samples in various amounts, and their effects on sludge dewaterability were evaluated. Surfactants were also added with either cationic or anionic polymers to better understand their effects on the mechanism of sludge conditioning and the feasibility as coagulant aid.Experimental results indicate that applying surfactants alone in sludge system decrease the filterability of sludge, but increase the sludge dewatering rate at optimum dosage. Cationic surfactant was proven possible as conditioning aid for the cationic polymer. The order of surfactant and polymer addition is the key to additive function. On the other hand, when the polymer of opposite charge was added with the surfactant, co-precipitation occurred which resulted in decreased filterability and dewaterability.
The Noell Conversion Process – a gasification process for the pollutant-free disposal of sewage sludge and the recovery of energy and materials
Authors: Jaeger M. , Mayer M.
Published: May 2018

The Noell Conversion Process was developed to guarantee the safe disposal of sewage sludge and other waste materials by means of thermal treatment, evenwith very strict emission standards. The center piece of this process is a pressurized entrained flow gasifier. The reactin conditions in this gasifier does not only suppresses the formation of dioxins and furans, but also completely destroys any dioxins and furans contained in the waste materials. Another advantage of the Noell Conversion Process referring the thermal treatment of sewage sludge is the recovery of marketable substances such as synthesis gas, sulphur and vitrified slag. To demonstrate this advanced technology in the field of sewage sludge treatment, Noell-KRC has built a pilot plant in Freiberg/Germany. This plant was designed for a throughput of 0.5 Mg/h (dry base) of sewage sludge. During the operation of the plant from 1996 until 1998, it was possible to demonstrate that there are no problems with emissions of heavy metals like Mercury or organic components like Dioxins and Furans. The H2 rich gas produced in the process can be utilized as a power source. The vitrified slag produced in the process is of a quality suitable for use as a construction material with a wide range of applications.
Treatment of sewage sludge using hydrothermal oxidation – technology application challenges
Authors: Shanableh A. , Shimizu Y.
Published: May 2018

The objective of this paper is to examine the technical feasibility of hydrothermal oxidation as a sewage sludge treatment option. Hydrothermal oxidation involves treatment at temperatures and pressures below and above the critical point for water, 374.2°C and 22.1 MPa. Subcritical water oxidation (SubCWO) achieves incomplete sludge oxidation (<95% COD removal) and produces high-strength liquors containing significant quantities of volatile fatty acids (VFAs). Controlled liquor recycling into the treatment plant can provide a useful carbon source to support biological nutrient removal (BNR). SubCWO also achieves efficient destruction of the organic component of sludge solids, resulting in significant mass and volume reductions. Supercritical wateroxidation (SCWO) on the other hand can completely oxidize the organic component of sludge (>99.9% COD reduction), produce high quality effluents and disposable ashes and air emissions. The major engineering challenges associated with developing hydrothermal treatment systems, especiallySCWO systems, are solids management, corrosion and safety. Thesolids management challenge relates to scale formation, including deposition of inorganic salts and transport of suspended particles. The corrosion challenge relates to handling highly halogenated and extreme-pH waste streams. Nevertheless, the available body of technical knowledge supports the design of efficient SCWO sludge treatment systems.
Options for beneficial reuse of biosolids in Victoria
Authors: van Oorschot R. , de Waal D. , Semple L.
Published: May 2018

This paper presents a synopsis of current biosolids management in Victoria as well as an overview of some biosolids processing technologies. Indicative capital and annual costs to upgrade wastewater sludge management facilities at Victorian wastewater treatment plants to maximise safe beneficial reuse of biosolids and sludge products are provided.

The data will be particularly useful for preliminary assessment and planning purposes of biosolids management strategies for government, non-metropolitan urban water authorities and regional waste management groups.

Indicative cost curves are presented for various sludge treatment and biosolids reuse options applicable to treatment plant sizes between 2000 and 200,000 ep.
EU legislation concerning wastewater treatment _ tasks for wastewater treatment developments in Hungary
Authors: Fleit E. , Bagyinszki Gy. , Vimola D.
Published: May 2018

The primary aim of the paper is to assess and to compare the present Hungarian environmental legislation and that of the European Union in the field of wastewater collection and treatment. Outline of the necessary development and future priority tasks for the Hungarian wastewater industry are evaluated in detail.
Evolution of the Southpest Wastewater Treatment Plant
Authors: Jobbágy A. , Literáthy B. , Farkas F. , Garai Gy. , Kovács Gy.
Published: May 2018

The treated effluent of the Southpest Wastewater Treatment Plant is discharged into a small, low-flow branch of the Danube susceptible to eutrophication. The first, high-load activated sludge system with a hydraulic retention time of 2.5 hrs in the aerated basins, was installed here in 1966. The paper presents the evolution of the technology by illustrating the effects of the different changes carried out since 1991.

Reconfiguration of the existing activated sludge basins connected originally in parallel into an arrangement of tanks in series increased the settleability of the sludge as well as the efficiency of COD removal significantly. Introduction of an anaerobic zone preceding the aerated basins facilitated biological excess phosphorus removal with a consequent release in the thickener and digester. Introducing lime addition into the recycled sludge processing wastes significantly improved the performance of the system. However, since there had been no provision built for eliminating the nitrate content of the recycled sludge, efficiency of phosphorus removal proved to be dependent on the eventually occurring nitrification.

In order to achieve both an effective nitrogen and phosphorus removal the current technology established in 1999 applies a nitrification and a denitrification filter following the activated sludge unit and uses precipitation for phosphorus removal.
Critical factors for implementing sludge processing of the Rome Wastewater Treatment Plants
Authors: Mininni G. , Salera A. , Rolle E. , Carucci A.
Published: May 2018

The use of sludge thermal drying after mechanical dewatering implies a sharp increase in capital costs but can be effective in reducing both transport and disposal costs. In this paper the most critical factors affecting economics in implementing with sludge thermal drying the four wastewater treatment plants serving the city of Rome are discussed. As alternatives, replacement of belt presses with filter presses in the plant of Rome East, due to the low concentration of sludge cake (18%) presently produced, and centralised treatment in the plant of Rome South of the sludge produced in this plant and in the plant of Rome Ostia are also considered. Thermal drying appeared more convenient especially when dewatering operation is poorly performed (Rome East), but in the large plants (Rome South alone or with Ostia) the upgrading of the plant is always economical. Other contingent and local situations can also play an important role in this prospect (distance from the landfill site, transport and disposal unit costs), thus making not convenient the adoption of thermal drying for the plants of Rome North and Ostia. For disposal cost lower than 52 ECU/t replacement of the present belt presses with filter presses in Rome East plant is more advantageous than the construction of a drying plant.
WWTPs in rock – an economical and environmental alternative
Authors: Andersson C. , Hultgren J.
Published: May 2018

To meet increased load or requirements on effluent standards the upgrading of a WWTP may be carried out with a large biological stage meaning higher investment costs but lower operation and maintenance (O&M) costs, or with a compact biological stage meaning lower investment costs but higher O&M costs.

Henriksdal and Käppala WWTPs in Sweden, both built in rock with large biological reactors operated with pre-denitrification, show lower specific O&M costs than Himmerfjärden WWTP, operated with post-denitrification in a fluidised bed. It is the other way round for the specific capital costs. The total specific cost, which is the sum of the specific O&M and capital cost, is a useful tool when choosing an alternative for upgrading. The experiences from these three plants show that a “large volume alternative” is competitive with a “compact alternative” if the volumes can be available at a reasonable cost. With proper technology rock chamber plants may be comparatively cheap to build. The economical and environmental advantages are discussed in this paper.
Class B biosolids production from wastewater sludge with high pathogenic content generated in an advanced primary treatment
Authors: Jimenez B. , Barrios J. A. , Maya C.
Published: May 2018

Alkaline post-stabilization of wastewater sludge with high pathogenic content (up to 1010 NMP/g TS of Salmonella sp. and up to 89.8 helminth eggs/g TS) was studied to evaluate the feasibility of producing Class B biosolids. The sludge was produced in pilot systems using different advanced primary treatment processes treating wastewater generated in Mexico City. Samples were dewatered to different dryness ranging from 11.5 to 29.0% TS and stabilized using quicklime in doses ranging from 15 to 40% (w/w). The levels of pathogens found in dewatered sludge were up to 8 log and 1.95 log higher than those found in primary sludge generated in the United States for Salmonella sp. and helminth eggs respectively. Distribution of genera of helminths indicated that more than 90% of the eggs found were Ascaris, while the rest were Hymenolepis, Trichuris, Toxocara and Taenia. Minimum and maximum removals ranged between 3.6 to 9.5 log for fecal coliforms; 3.7 to 7.9 log for Salmonella sp.; and 0.1 to 1.3 log for helminths. The recommended quicklime dose was determined for different solids contents in order to achieve the pH-time criteria and the levels of microorganisms required by the US EPA. Metal concentrations were below the maximum levels established for land application of biosolids.
A modified capillary suction time apparatus for measuring the filterability of super-flocculated sludges
Authors: Vesilind P. A. , Örmeci B.
Published: May 2018

The capillary suction time (CST) test provides a quantitative measure of the rate of water release from a sludge and has the advantage of being simple to run. The test consists of allowing sludge water to filter into and penetrate a filter paper by capillary force. Although the CST works well for the majority of sludges, it is not a useful test for measuring the filterability of highly flocculated sludges or sludges conditioned by other methods such as freeze-thaw. The escape of water from the sludge in such cases is too fast and the rate-limiting step becomes the movement of water through the filter paper instead of the release of water from the sludge. There is a need to improve the CST apparatus so it can be used to measure the degree of filterability for super flocculated sludges as well. Such a device is described in this paper. It consists of first draining the free water from the well-flocculated sludge and only then allowing the flocculated sludge to come in contact with the filter paper.The results of our study show that the filterability of super-flocculated sludges can be measured with acceptable precision using the modified CST apparatus.
The good, the bad and the ugly: process modelling for design
Authors: Bingley M. , Upton J.
Published: May 2018

Severn Trent Water has considerable experience in process modelling of activated sludge systems. Using three case studies, this paper highlights some of the pitfalls as well as the successes encountered in Severn Trent's modelling history. The three case studies highlighted show when modelling has proven to be a great success; when modelling would have worked had all the relevant information been known and included; and when modelling simply does not appear to be the way forward. Reference is made to Minworth sewage treatment works serving Birmingham, the Milcote biological nutrient removal plant serving Stratford-upon-Avon, and Toton wastewater treatment works serving South West Nottingham. Alpha factors are shown as a key concern when providing suitable information for process design, and the use of pilot work as a means of verifying and backing up model results is also highlighted.
Design measures to increase the efficiency of secondary sedimentation tanks
Authors: Schlegel S. , Stein A.
Published: May 2018

Due to the fact that there is very little difference between the density of water and activated sludge, turbulences and energy inputs in secondary sedimentation tanks impair the sedimentation behaviour of the sludge particles. Consequently, all measures that reduce turbulence can be said to be positive and, thus, desirable. Bearing this in mind, a new type of secondary sedimentation tank has been developed. As hydraulic energy is predominantly introduced via the inflow, it is recommendable to feed the sludge/water mixture directly into the sludge layer on the bottom of the tank. In addition, sludge and water should, if possible, flow in the same direction. If these principles, which can be applied to both rectangular and circular secondary sedimentation tanks, are taken into account, the tanks can be designed more cost-effectively and efficiently.
Determination of the remaining stabilization potential of landfilled solid waste by sludge addition
Authors: Gülec S. B. , Onay T. T. , Erdincler A.
Published: May 2018

Ultimate disposal of wastewater sludges is one of the most concerning steps of sludge management. As an alternative disposal, reuse of sludge as a soil conditioner or fertilizer has had some success. Another alternative is the addition of sludge to the solid waste landfills. Many researchers have studied the effects of sludge addition to the solid waste stabilization in landfills. However, part of the researchers found positive effects, while others found either negative effects or no effects at all. This study investigates the remaining stabilization potential of the solid waste retrieved from an operating landfill by sludge addition. Determination of the remaining stabilization potential of landfilled solid waste is an important issue in solid waste management. In this study, the further stabilization of landfilled solid waste is achieved by the addition of anaerobically digested sludge to the solid waste with different sludge to waste ratios. Four 10-litre laboratory-scale batch digesters operated under constant temperature of 34°C are used in the experiments. One of the digesters was the control unit operated without any sludge addition. The other three digesters had different sludge to waste ratios; 1:9, 1:6, 1:4 (on wet basis) respectively, in order to find the optimum ratio for the solid waste stabilization. The comparison of gas production and quality and other indicator parameters provided an opportunity to determine the remaining stabilization potential and its significance. The results are translated in terms of conventional landfill practices, as well as emerging technologies for innovative sludge management.
Expenditure on the operation of municipal wastewater treatment plants for nutrient removal
Authors: Nowak O.
Published: May 2018

Operating costs of Austrian municipal treatment plants are evaluated for 1989/90 and for 1997, respectively. The results indicate that presently the expenses which can be directly connected to wastewater purification, i.e. energy and chemicals for P removal, comprise only about 20% of the total operating costs. Today, in Austria like in other EU countries, the predominating factor is “labour costs”, even at nutrient removal plants. A general scheme for estimating operating costs is presented that can be applied to WWTPs in other parts of the world. In this scheme the important factors relevant to the operating costs are integrated.
Synthesis of bioplastics from food industry wastes with activated sludge biomass
Authors: Wong A. L. , Chua H. , Lo W. H. , Yu P. H. F.
Published: May 2018

This paper describes the microbial production of polyhydroxyalkanoates (PHAs) from food industry wastes by a mixed culture of activated sludge microorganisms. The physical and chemical properties of the bioplastics produced by the microorganisms from malt and soy wastes were different. The melting points of the products were compared, and the co-polymer composition of the products was investigated by gas chromatography and nuclear magnetic resonance spectroscopy. In using activated sludge to convert the carbon source into PHAs, not only are environment-friendly bioplastics produced, but also the problem of disposing of municipal activated sludge is partly solved. The selection of food industry waste as the carbon source can also reduce the cost of producing PHAs.
Research needs for developing innovative water and wastewater treatment technologies
Authors: Bryan E.H.
Published: May 2018

Research aimed at solving important environmental problems at all scales ranging from global to individual will continue to be an essential part of the process by which sustainability of life on earth may be achieved. Solutions to environmental problems that relate to water are especially critical to this process and are likely to involve use of innovative technologies that emerge from research with sufficient promise to justify their development, a process that evaluates them at a scale that will yield engineering design parameters and confidence in their technical performance and economic value. Privatization of water and wastewater systems and mergers of equipment manufacturers may provide the economic bases needed for development of innovative water and wastewater treatment technologies in the 21st Century that have emerged from research in the 19th and 20th Centuries but have not as yet been fully developed or adopted.
An innovative approach to maximize primary treatment performance
Authors: Huang J.-C. , Li L.
Published: May 2018

This paper describes the development of a cost-effective modified primary treatment method which can significantly increase the removal of both soluble and colloidal COD without resorting to the use of any chemical coagulant. It involves recycling a small portion of the primary sludge and then activating it to enhance its biosorptive and flocculent properties through 30-min aeration. The aerated sludge is then brought into contact with raw sewage to induce rapid biosorption of soluble COD and flocculation of colloidal organic before the mixture is settled in a regular primary clarifier. In this treatment approach, the raw sewage is not subjected to aeration; thus the sludge aeration tank volume and the aeration energy requirements can be minimized. In fact, with 30-min sludge aeration, theyamount to only 1.25% and 8.5%, respectively, of those required in the conventional activated sludge system. Through this modified approach with a 15% sludge recycle rate and 30-min sludge aeration, the COD removal efficiency is 43.9% higher than that of the regular primary treatment. This would result in a significant improvement of the primary effluent quality, or achieve a substantial reduction of organic loading to the secondary biological system.
Groundwater quality monitoring
Authors: Belgiorno V. , Napoli R.M.A.
Published: May 2018

The paper describes results of monitoring activities of groundwater in a rural area carried out to verify the impact on water quality in an uncontaminated area resulting from the initiation of an atmospheric pollution source. Significant emissions of nitrogen oxides from the pollution source resulted in particular attention to verifying the increase of nitrate concentrations in monitored water. Over 10,000 analytical tests including several chemical parameters were conducted in the full monitoring period. In the paper, a first reading of data, graphical trends and non-parametric statistical analysis are presented. Measured values for nitrates, nitrites, hardness, alkalinity and pH showed poor variability during the entire period. Checked parameters were in the usual ranges of uncontaminated rural areas and comparisons between meaningful values of the periods ante operam and post operam do not show any degradation of water quality following the atmospheric pollution source activity. Nitrites are occasionally found in some spring water due to organic pollution, confirmed by the randomness with which their presence was detected.
The community structure of Lake Kinneret (Israel) microorganism populations: size distribution and succession
Authors: Bergstein Ben-Dan T. , Wynne D. , Shteinman B. , Hu Z. , Kamenir Y.
Published: May 2018

The abundance and succession of bacterial populations, and their biovolume has been studied in the deepest station of Lake Kinneret, Israel during spring–summer. These parameters were then related to the chemical, biological and physical/hydromechanical conditions in the lake. Medium sized cells (2–3 μm) dominated the bacterial population in the spring, then in mid-summer the smaller cell fraction (1 μm) took over. Relatively low numbers of large cells (10 μm) were counted, but the biovolume of this fraction was significant, especially in mid-summer. Both the abundance and biovolume of medium sized cells were positively correlated with NH4+ and O2 concentrations, but not with NO3–, inorganic orthophosphate (Pi) and Total-P. At water temperatures above 28°C, the biovolume of medium sized cells decreased, probably due to faster grazing of zooplankton. When water circulation in the vertical plane was dominant, large cells disappeared from the water column, due to sinking to the bottom. We conclude that chemical parameters, such as NH4+ and O2 concentrations, had a long-term effect on bacterial succession and size distribution, whereas hydromechanical mechanisms, such as turbulent mixing in the horizontal or vertical planes, had a short-term effect.
Phenol remediation by biofilm developed in sand soil media
Authors: Antizar-Ladislao B. , Katz S. , Galil N.I.
Published: May 2018

Laboratory scale sand columns were used in order to evaluate biodegradation of phenol, simulating the conditions which could be created in the non-saturated (vadose) zone by an accidental spill on the top of the soil, biologically remediated by a controlled recycled aqueous flow, enriched by the necessary nutrients. The parameters which have been studied as possible factors influencing the biodegradation process by fixed film biomass, included: (a) the effective size of the sand grain, coarse sand of 2.51 mm and medium sand of 0.81 mm operated in two different columns; (b) flow rate of the aqueous phase recycled through the columns, 0.090, 0.120 and 0.176 bed volumes/hr; (c) different initial loading of phenol applied on the top of the columns, 4, 5 and 6 grams. Daily monitoring of the experimental system included analyses of phenol, COD, turbidity, pH, ammonia, phosphate and suspended solids. Removal efficiencies of phenol were found to be high, close to 100%, within the first seven days following the exposure, indicating high rates of biodegradation. Measurements of volatile attached solids (VAS) connected to the sand, quantitatively indicating fixed film biomass, were higher at the top region and lower at the bottom, at a depth of about one metre: 44.5 and 28.1 mg VAS/gram of dry sand were obtained in the coarse sand column, 10.6 and 4.1 mg VAS/gram of dry sand in the medium sand column, respectively. The general yield coefficient was found to be 0.57 gram VAS/gram of phenol biodegraded. The results indicated that the medium sand size resulted in a slightly better performance, especially in cases of high flow rates, however, coarse sand showed quicker acclimation of microorganisms to biodegrade the phenol. Low rates of flow resulted in more effective biodegradation of phenol. High loading of phenol applied on the top of the columns inhibited, apparently, the microbial activity within the sand columns.
Soluble microbial product formation during biological treatment of fermentation industry effluent
Authors: Goorany O. , Oztürk I.
Published: May 2018

The most important factor that affects the quality of effluents and overall organic matter removal in biological treatment processes is the presence of soluble microbial products (SMP) that are produced during biological treatment and remain in effluent. High strength wastewater from fermentation industry (FIE) was used as a slowly degradable substrate to investigate SMP formation in aerobic and anaerobic treatment. For SMP determination which forms a major part of residual soluble COD of the wastewater, the initial inert soluble COD (SI) was determined. It was found that SI/So is 0.122 and 0.164 for aerobic and anaerobic processes, respectively. During aerobic treatment of FIE for initialCOD (So) values varying between 1540–6645 mg COD/L, SMP are expected to vary within the range of 12.5–8.6% of So, respectively. In anaerobic treatment of the FIE, for values of 2670–6585 mg COD/L, SMP are expected to vary within the range of 9.8–6.2% of So, respectively. Molecular weight distribution analyses of raw wastewater, aerobic and anaerobic treatment effluent indicate that in both systems the effluent of FIE presents similar molecular weight fractions and are very high compared to raw wastewater.
Distribution of fecal coliforms in the Jordan river mouth originating from anthropogenic activities in the watershed
Authors: Hadas O. , Shteinman B. , Pinkas R.
Published: May 2018

The main inflow to Lake Kinneret is the Jordan River. A spit and a bar characterize the area where it enters the lake. The main processes occurring at the entrance are mixing, sedimentation and dispersion of the sediments. In the present study an interdisciplinary biological, physical and chemical approach was applied in order to follow the distribution of bacteria and river alluvium at the mouth of the river and relate the observed distribution to attenuation in velocity along the jet stream. The results showed that the jet flow rapidly attenuates when the Jordan enters the lake. The strong gradient in salinity indicated rapid mixing near the inflow. The distribution of fecal coliforms and fluorescent tracers indicated that the maximal longitudinal gradient was at the bar. Thus, bacteria and fluorescent tracers can be used as indicators of the distribution of particles originating in the Jordan River and entering the lake. Most of the parameters studied were found to vary in accordance with attenuation of the flow velocity as the jet diverges and disintegrates. Sedimentation dominated from the entrance to the bar and beyond the bar mixing (dilution) processes dominated.
Rainwater catchment and the challenges of sustainable development
Authors: Heggen R.J.
Published: May 2018

Early mankind impounded rainfall in rock caverns for consumptive needs. The first farmers situated plots below slopes where runoff could be diverted. Rainwater catchment was an early step in pursuit of sustenance. What is ancient in one respect, however, remains new in another. Rainwater catchment is today employed worldwide for potable and agricultural water supply. Technology is advancing in roofing, guttering and storage, water quality protection and distribution. Catchments abound in both developing and economically advanced nations. Applications include both adaptations to traditional dwellings and modern architecture. Fundamentally more changed than new technology or applications, however, is the viewpoint from which rainwater catchment can be evaluated. Rainwater catchment is a systems problem, a collection of interactive components best understood not as parts, but in their interrelationship. So viewed, rainwater catchment merits consideration as a component of sustainable water resource development. This paper reviews the challenges of rainwater catchment in sustainable development.
Water quality control in open channels
Authors: Hof A. , Schuurmans W.
Published: May 2018

With the increasing degree of automation in Dutch water management the need for control systems and design procedures for control systems is also evolving. Traditionally these control systems were used for water level and discharge control only. With the measurement equipment that is currently available, improved water quality control also becomes possible. A PhD researcher is currently investigating the theoretical implications. The design of a reliable control system using control theory requires a linear description of the relevant processes. A possible linear description of the relevant processes is presented in this paper.
The rising water level in Lake Van: environmental features of the Van basin which increase the destructive effect of the disaster
Authors: Kılınçaslan T.
Published: May 2018

Lake Van, the largest in Turkey and fourth largest in the world is situated in a closed basin. The water level in Lake Van has increased by about four metres since the mid sixties causing serious environmental damage. It is known that this problem does not only pertain to Eastern Anatolia, but changes in water levels of lakes in Iran and Azerbaijan are also being observed. Thus, the problem seems to be regional rather than local. Research was conducted in order to evaluate the existing physical features of the Van Basin and to develop a proposal for allocation of the Van residents which are under flood threat. This paper presents the general features of the basin associated with water fluctuations and evaluates thesettlement condition relative to the change in the lake water level.
Sustainable management of water resources and international law
Authors: Marchiso S.
Published: May 2018

The need is being increasingly felt within the international community for more careful consideration of the legal and institutional aspects involved in the use and management of water resources. Existing legal regimes, both national and international, may have no provisions for regulating or controlling new needs for sustainable management of waters. Innovative legal frameworks for water must thus be designed to both facilitate and achieve efficient allocation or reallocation of resources for environmental protection and proceed towards the attainment of social, economic and more general sustainable development goals. The no-harm rule, the equitable apportionment principle and the duty of consultation and negotiation among riparian or sharing States are now integrated by rules and standards pertaining to the new branch of international law on sustainable development: the duty of co-operation, the precautionary principle, the prevention rule, the polluter-pays principle, the environmental impact assessment requirement, which are gaining relevance also in the context of international water resources law, as shown by the 1997 New York Convention on the Law of the Non-Navigational Uses of International Watercourses. Sustainable water management also implies widespread adoption of good governance principles that ensure broader participation in development decisions and an open decision-making process. In developing and using water resources, priority has to be given to the satisfaction of the basic right to water. This paper intends to identify an effective legal international regime for management of water resources, compliant with sustainable development principles solemnly asserted within international law.
Anaerobic treatability of leachate: a comparative evaluation for three different reactor systems
Authors: Timur H. , Ozturk I. , Altinbas M. , Arikan O. , Tuyluoglu B. S.
Published: May 2018

In this study landfill leachate from two young municipal landfill sites were treated in three bench-scale systems including anaerobic sequencing batch reactors (ASBR), anaerobic hybrid bed filter (AHBF) and upflow sludge blanket reactor (UASBR) at mesophilic conditions. The experimental studies have been conducted at variable influent leachate CODs of 1900–19000 mg.l–1 and hydraulic retention times (HRT) of 10 to 1.5 days and solid retention times (SRT) of 40 to 10 days in ASBRs. Influent leachate concentrations and HRT's of AHBF were varied in the range of 4000 to 15000 mg.l–1 and 5.1 to 0.9 days, respectively. Anaerobic treatability studies have been performed for about 20 months using 3.5 year old landfill leachate for ASBR and AHBF. The anaerobic treatability of the second leachate which was only two years old was investigated in the lab-scale UASBR for about 4 months. The influent CODs of the UASBR were varied from 9000 to 25000 mg.l–1. HRTs ranged from 1.7 to 2.35 days in the same period. COD removals were in the range of 92 to 94% at the related operating conditions. The steady-state performance data of anaerobic reactors fit quite well to the linearized second-order multicomponent substrate removal kinetic model with a correlation of more than 98%.
The influence of water column density shifts on vertical transport of dissolved chemicals: applications to problems of monitoring and predicting water resource quality
Authors: Kushnir V. , Shteinman B. , Kamenir Y.
Published: May 2018

A steep gradient density layer (density shift) in a water column often forms due to intense summer heating of the surface and wind mixing the upper layer. It influences the vertical transport of chemicals and pollutants, due to the significant power generated, overcoming Archimedes forces. The mechanism of vertical transport of dissolved chemicals through the density shift is connected with the stochastic formation of local turbulent structures – “turbulence flares”, which arise because of shifts of current speed in internal waves and eddy-wave formation of the “billows” type. Analyses of data from the Black Sea and Lake Kinneret indicate the universal character for conditions of the dimensionless dependence of logRi = f(Z/Zm) and logRi = f(2logN/Nm), where Ri = the Richardson number, Z = depth, Zm = the depth of the Brunt-Vaisala frequency N(Z) maximum (Nm). A high positive correlation (R = 0.75) between logRi and 2 logN/Nm values allows the use of vertical density profile data (water temperature) for estimating the vertical fluxes of chemical elements and pollutants. The simplicity of measurement and availability of data on density structure of water basins provide means for effective monitoring of vertical transport of chemical elements and pollutants under various conditions.
Pigment variation in the photosynthetic sulfur bacterium Chlorobium phaeobactereoides from Lake Kinneret
Authors: Yacobi Y.Z. , Ben-Bassat E. , Murad D. , Eckert W.
Published: May 2018

The photosynthetic sulfur bacterium Chlorobium phaeobactereoides found in Lake Kinneret harbors three homologues of bacteriochlorophyll e (Bchl e). The ratios between the Bchl e homologues found in samples from the metalimnion are approximately constant and perennially stable. The proportion of Bchl e homologues in a laboratory isolate of Ch. phaeobactereoides was different from that found in the lake population, but resistant to changes in light, even if cultures were exposed to light intensity 2-3 orders of magnitude higher than the intensity experienced by the bacterium under natural conditions. Exposure of cultures in the lake did not induce changes in the proportion of pigments, indicating that the isolate maintained in the culture collection is intrinsically different from the genotypes that build up most of Ch.phaeobactereoides in Lake Kinneret. We found a positive relationship between light intensity and carotenoid content in laboratory experiments implying the photoprotective role of those compounds. The laboratory isolate also showed two unknown carotenoids, never found before in lake samples. Those carotenoids are less polar than -carotene, and showed absorption peaks at 427 and 451 nm, and 429 and 451 nm, in methanol.
Calibration of kinetic parameters in the IAWQ Activated Sludge Model: a pilot scale experience
Authors: Satoh H. , Okuda E. , Mino T. , Matsuo T.
Published: May 2018

The parameters in the mathematical simulation model for the nutrient removal activated sludge process were calibrated by using operational performance data obtained on enhanced biological phosphorus removal activated sludge processes treating urban sewage. By changing five parameters, maximum specific growth rate of nitrifiers, saturation constant of ammonia for nitrifiers, maximum specific hydrolysis rate under anaerobic conditions, maximum specific fermentation rate, and maximum specific polyphosphate accumulation rate of polyphosphate accumulating organisms (PAOs), the process performance was well reproduced by simulation. For the improvement of simulation, inclusion of the formation or presence of soluble COD which is not utilized by PAOs either directly or via fermentation was proposed.
Nitrogen removal in a submerged filter with no effluent recirculation
Authors: Chui P.C. , Terashima Y. , Tay J.H. , Ozaki H. , Jeyaseelan S.
Published: May 2018

The performance of a partly aerated submerged filter in treating high nitrogenous wastewaters such as industrial effluents after anaerobic treatment was investigated in this study. The filter was operated without effluent recycling and its response to various test conditions of aeration rates, hydraulic loads, COD/N ratios and hydraulic retention times was evaluated. Results indicated that for an influent concentration of 250 mg N/L and for a loading rate of 0.7 kg N/m3.d, 60% of the nitrogen can be removed. For a reduced loading rate of 0.25 kg N/m3.d, nitrogen removal efficiency could reach 86%. Denitrification was hypothesized to have taken place inside the support media in the aerated zone of the filter where oxygen was lacking as well as at locations immediately below the air diffuser where an anoxic zone was formed with the back-flowing nitrified substrate.