bluuebunny/crossref_metadata_2025 huggingface dataset:
Behaviour of Coli Phages in Oxidation Ponds
Authors: Omura T. , Shin H. K. , Ketratanakul A.
Published: May 2018

Coliphages are among the most promising indicators of viral inactivation efficiency of wastewater treatment. Therefore, it is important to investigate the behaviour of coliphages in oxidation ponds from the viewpoint of predicting the inactivation of infectious viruses. In this study, numbers of coliphages were measured in oxidation ponds consisting of a series of facultative and maturation ponds. In parallel with this investigation, the effects of temperature and pH on the behaviour of coliphages were examined in the laboratory, employing three species of coliform bacteria as host cells.

The field investigation showed that there was positive correlation between counts of coliphages and those of coliform bacteria, and that more than 99% of coliphages were inactivated. The inactivation efficiency of coliphages in the facultative pond was much higher than in the maturation pond. The results of the laboratory experiments indicated that at 30°C more than 99% of the coliform group were destroyed in 7 days of incubation and that coliphages counts increased from 105/100 ml to 107/100 ml with a lag time of 3 days. Greater reduction of the coliform count was obtained at higher incubation temperatures. It was observed that the coliphages possessed greater ability to attack coliform bacteria at acidic rather than alkaline pH.
Location of Phosphorus in Activated Sludge and Function of Intracellular Polyphosphates in Biological Phosphorus Removal Process
Authors: Mino Takashi , Kawakami Tomonori , Matsuo Tomonori
Published: May 2018

The STS method, a method for the fractionation of intracellular phosphorus, was introduced into the examination of the phosphorus location of activated sludges, and some basic aspects involved in the biological phosphorus removal process were investigated from biological points of view. Although both lowmolecular and highmolecular polyphosphates appeared in the sludges produced in the biological phosphorus removal process, the high phosphorus content of the sludges was caused mainly by the accumulation of lowmolecular polyphosphates and lowmolecular polyphosphates were principally responsible for the release and uptake of phosphorus. The turnover of phosphorus in lowmolecular and highmolecular polyphosphates was investigated by using 32P-labelled orthophosphate as a tracer. The phosphorus turnover in lowmolecular polyphosphates was not observed under both anaerobic and aerobic conditions, while the phosphorus turnover in highmolecular polyphosphates occurred under the aerobic conditions. It was indicated that lowmolecular polyphosphates function as the energy pool under the anaerobic conditions and that highmolecular polyphosphates function as the phosphorus source for the microbial growth.
Oxidation of Sulfide and Thiosulfate and Storage of Sulfur Granules in Thiothrix from Activated Sludge
Authors: Nielsen P. H.
Published: May 2018

Thiothrix from activated sludge is, in the presence of oxygen, able to oxidize sulfide and thiosulfate and store many clear sulfur granules at sulfide concentrations less than about 1 mM and thiosulfate concentrations of 0.1-20 mM. On this basis, a sulfur storage test for the identification of Thiothrix in activated sludge was developed. It is shown that the filamentous bacteria, Type 021N (commonly causing bulking in sewage plants) , is able to store sulfur granules and thus is a Thiothrix. In enrichment cultures with thiosulfate typical Thiothrix rosettes and motile gonidia are developed, and the presence of a sheath is demonstrated. Filamental diameter varies between 0.8-2.4 µm, the youngest filaments being thinnest. Attempts to isolate Thiothrix have been unsuccesful, but Thiothrix filaments with only a few contaminants are able to grow on solid media with acetate as the only carbon and energy source, indicating the presence of heterotrophic strains. The filamentous organisms of 14 Danish sewage treatment plants are identified, Thiothrix being the most common in 8, and responsible for bulking in 4 plants.
An Equalization Control Strategy for Activated Sludge Process Control
Authors: Dold P. L. , Buhr H. O. , Marais G v. R.
Published: May 2018

Fluctuations in hydraulic and organic loads cause wastewater treatment plant operating problems, necessitating some form of process control to ensure attainment of design objectives. A comparison of in–plant control with equalization control indicates that the latter is more appropriate for the case of long sludge age nutrient removal activated sludge processes which include anaerobic, anoxic and aerobic zones. A microprocessor-based control strategy is presented for the operation of an equalization tank upstream of the process to reduce, optimally, diurnal fluctuations in both flow and organic load rates. Results from implementation on a 150 Mℓ.d−1 plant with an in-line equalization tank (4,5 hour mean retention time) demonstrate the successful performance of the control strategy.
The A–B Process: A Novel two Stage Wastewater Treatment System
Authors: Versprille A. I. , Zuurveen B. , Stein Th
Published: May 2018

New acts on wastewater disposal demand for higher process stability and effluent quality.

The A-B process, a novel two step treatment system, meets these requirements in a cost effective way.

Five full-scale plants have been put in operation over the last two years.

The objective of this paper is to give an outline of the features of the A-B system in the context of the results of these full-scale plants.

In spite of the extreme high load, the A-stage can be operated at a high reduction rate and is stable. Variations in the organic load and pH- and toxic shocks are leveled out and a constant, mainly soluble effluent is supplied. This implicates a low sludge production in the B-stage. As a consequence higher overall reduction rates are obtained as compared to conventional processes at the same sludge load. Very low and stable final effluent concentrations are observed in all full-scale plants.

Of special interest are the possibilities of upgrading existing conventional treatment facilities, at minor costs, by incorporating the A-B technology.

The A-B process therefore can be considered as a very promising, cost effective alternative for both existing and new wastewater treatment plants in responding to the increasing effluent demands.
The Application of Predenitrification Nitrification Technology for Trace Contaminant Control
Authors: Melcer H. , Nutt S. G.
Published: May 2018

Predenitrification nitrification (PDN) technology was applied in two stage anoxic-aerobic systems treating coke plant wastewaters and coal liquefaction process condensates. Both activated sludge and biological fluidized bed modes of operation were investigated for their potential to remove ammonia, phenol, thiocyanate, cyanide and a wide range of trace organic contaminants. It was demonstrated that during nitrification of these complex wastewaters, simultaneous removal of most of the conventional and trace organic contaminants was achieved. Specifically, of the base/neutral extractable organic compounds, only di-n-butyl phthalate was consistently found in treated effluent samples at greater than trace levels (0.01 mg/l). It appears that trace organic contaminant control in complex industrial wastewaters can be achieved by the application of PDN technology.
Single Sludge Anoxic–Aerobic Systems for Biological Treatment of Coke Plant Wastewaters
Authors: Beccari M. , Di Pinto A. C. , Passino R. , Ramadori R. , Tandoi V.
Published: May 2018

A study on the biological treatment of coke plant liquid wastes, with high concentration of ammonium nitrogen and phenols, is presented. The anoxic-aerobic single sludge process is used, with the phenols as electron donors in the denitrification process; the inhibiting effect of toxic substances present in the wastewater is prevented by means of dilution. Tests were conducted in a laboratory scale plant to determine the minimum dilution ratio necessary to avoid inhibition and the parameters required for the designing of a full scale plant. Finally the basic design considerations of a wastewater treatment plant for a 1000 t/d coke plant are reported and capital and running costs are evaluated.
Decontaminating Biological Sludge for Agricultural Use
Authors: Wong L. , Henry J. G.
Published: May 2018

A biological oxidation process called bacterial leaching was used to remove heavy metals from anaerobically digested sewage sludge. The purpose was to decontaminate the sludge so that it could be utilized on agricultural land. The leaching process was found to be affected by pH, aeration and temperature. At α pH of 4, an aeration rate of 100 cm3 of air per litre of sludge per minute and a temperature of 25°C, the following metal removal efficiencies were observed: cadmium, 80 - 85% ; copper, 66 - 80% ; nickel, 70 - 78% and zinc, 84 - 90%. No significant removal was observed for lead. In addition to removing heavy metals, bacterial leaching preserves the soil conditioning and fertilizing properties of the sludge. According to Ontario guidelines, the sludge used in this study was initially not acceptable for use on agricultural lands. However, after bacterial leaching, all criteria for the application of sludge to agricultural lands were easily met.
F Specific RNA Bacteriophages in Sewage: Methodology and Occurrence
Authors: Havelaar A. H. , Hogeboom W. M. , Pot R.
Published: May 2018

F specific RNA (FRNA) bacteriophages are attractive models for the study of the fate of animal viruses in water treatment processes and pure cultures (MS2, f2) have frequently been used in model experiments. The use of indigenous FRNA phages has been hampered by the lack of selective enumeration methods. Usually, bacteriophages in sewage are enumerated by counting the number of plaques produced in a lawn of an Escherichia coli host strain. Both somatic and F specific phages will contribute to the count. We report the development of a simple and highly selective method, based on a specially constructed host strain of Salmonella typhimurium (WG 49, phage type 3 Nalr (F'42 lac :: Tn5)). Counts on this host strain normally originate exclusively from F specific phages, because there are only few somatic Salmonella phages in most sewage samples. FRNA phage counts from natural sewage samples using this host strain are more reliable and higher than those obtained on E. coli hosts. F specific bacteriophages were detected in all sewage samples investigated in numbers ranging from 102 − 5 × 104 pfu/ml. Data are presented on the number and types of F specific phages in mixed domestic/industrial sewage; in poultry processing wastewater and in hospital wastewater. The potential of F specific phages as water quality indicators is discussed.
Occurrence of Viruses in Treated Drinking Water in the United States
Authors: Akin Elmer W.
Published: May 2018

Health concerns regarding waterborne transmission of enteric viruses began to develop around 1940 in the United States (U.S.) with the isolation of poliovirus from human feces and sewage. The implication of these isolations for the transmission of viral disease through contaminated drinking water stimulated research on methodology for virus detection, recovery and assessment from water. Although virus methods research is still an important area of study, relatively sensitive procedures became available during the past decade for recovering many enteric virus types from large-volume samples of drinking water. Controversy surrounded many of the early reported isolations of viruses from treated drinking water using these procedures due to the suspicion of laboratory contamination. The occurrence of viruses in drinking water treated by currently accepted procedures has still not been proven by the U.S. experience although the likelihood may be gaining support. However, a virus survey of 54 water supplies and extensive studies of two water systems by the U.S. Environmental Protection Agency did not demonstrate viral contamination of treated water derived from surface sources.
Waste Water Recycling by Duckweed for Protein Production and Effluent Renovation
Authors: Oron Gideon , Wildschut Louw R. , Porath Dan
Published: May 2018

Waste water treatment and recycling facilities are becoming increasingly necessary in arid zones, especially in the light of the shortage of conventional water sources. The simultaneous treatment of waste water and the production of duckweed in a pond system, as an alternative protein source, is an attractive proposition for solving the feed and water shortage problem.

Outdoor experiments conducted in mini-ponds showed that duckweed ponds may be highly competitive with existing secondary treatment methods. The duckweed biomass, with a crude protein content of above 30% (dry weight), may be used as an alternative source for animal feed. The ease of the duckweed harvesting makes the system even more economically attractive.

The work describes the basic outdoor biotechnology aimed at eliminating the superior organic loading in the pond as given by the ratio of COD and NH+4 in the raw domestic sewage. This ratio was examined in respect to the retention time of the wastes in the ponds and protein production by the floating vascular plant biomass.
Erosional Process of Cohesive Sediments
Authors: Kusuda T. , Umita T. , Koga K. , Futawatari T. , Awaya Y.
Published: May 2018

Tests on erosion of the cohesive sediments in the Chikugo estuary in Japan were conducted. The results indicate that the decrease in the rate of erosion at constant shear stresses is caused rapidly 20 to 30 minutes after the start of tests and that tue decrease is caused by the increase in the solid fraction and the yield value of the seaiment remaining uneroded due to shear stress. In order to simulate the erosion process of sediments, a model in which the increase in the yield value of sediment is assumed to be proportional to the integration value of the absolute value of the sediment velocity gradient with respect to time was developed. The simulation based on this model is shown to be available to estimate the amount of sediments eroded in the erosional process of cohesive sediments.
Stream Modeling of Non-Convetional Water Quality Parameters: Phenol, Cyanide, Ammonia, Oil and Grease
Authors: Shahalam Abul Basher M. , Burke Dennis A.
Published: May 2018

Due to complexities in the water uses of the modern time, the water quality management often needs much information in addition to the traditional DO and BOD data, to impose any kind of control on the industrial and municipal discharges into natural streams. The simplistic Monod type of substrate limiting kinetics are not sufficient to express the fate of complex chemicals such as phenol, cyanide, ammonia, oil and grease.

This paper presents the kinetics of physical and biological degradation and transformation of such chemicals in the natural waters. The kinetics were developed through the multiple regression analysis using the data monitored over a year from a river in Pennsylvania, USA. The conventional unidirectional hydraulic transport and mass balance equations were then combined with these kinetics to predict the steady state water qualities in various reaches of the river under a specific set of known external discharges. When compared to the monitored water quality data under that specific set of external discharges, the predictions were found to be satisfactory. Some disagreement was observed in cyanide concentrations in the most down stream section of the 25 mile stretch of river.
Modelling of Oxygen Depletion in Coastal Waters
Authors: Malmgren-Hansen A. , Mortensen P. , Møller Bo
Published: May 2018

The relative importance of nutrient loadings and hydrographical and meteorological conditions for oxygen conditions in the Thisted Bredning, Denmark were evaluated by intensive survey and model calculations. The influence of wind speed on the vertical mixing in the unstratified shallow waters was quantified and tested in an oxygen model. The significance of oxygen consuming biological processes on the oxygen conditions were tested. By the use of a eutrophication model, the influence of local discharges of sewage on the size of the oxygen producing and oxygen consuming processes in the Thisted Bredning was calculated. Calculations showed that only a minor increase in rates of the oxygen consuming processes result in a drastic rise in the probability of oxygen depletion.
Ozonation of Non-Ionic Surfactants in Aqueous Solutions
Authors: Narkis Nava , Ben-David Bella , Rotel Malka Schneider
Published: May 2018

The effect of ozone on dilute aqueous solutions of a series of non-ionic surfactants of nonyl phenol ethoxylates, with n=4 to 30 ethylene oxide groups, dinonyl phenol ethoxylate and a polyethylene glycol were investigated. Assuming ozone concentration in solution to remain constant throughout the ozonation, the experiments showed first-order reactions with respect to surfactant concentration, as measured by the Wickbold method, and also with respect to COD & TOC. A linear relationship was established between the first-order reaction rate constants, and between n, the average number of ethylene oxide groups in the ethoxylate chain of the nonyl phenol ethoxylate series.

The oxidation mechanism by ozone of non-ionic surfactant molecules is explained as mainly polyethoxylate chains' cleavage into shorter polyethylene glycols and to a smaller extent oxidation of the aromatic ring. High ozone doses do not convert the non-ionic surfactant completely to CO2 and H2O but smaller doses are sufficient to enhance biodegradation.
Chronic Pollution of Intercity Motorway Runoff Waters
Authors: Balades J. D. , Cathelain M. , Marchandise P. , Peybernard J. , Pilloy J. C.
Published: May 2018

From 1980 to 1982, two investigations of the chronic pollution of roadway runoff water were carried out in areas having different pluviometric characteristics. The runoff from two hundred pluviometric events was characterized using highly rigorous methodologies, with a view to estimating the annual pollution load.

The annual loads were determined; they show that the official instructions hither-to followed were rather pessimistic. On the other hand, greater vigilance is required as regards the loads that may be contributed by an isolated event, but it is not possible to characterize the parameters that will give rise to such an event. A few rain events can introduce into the environment, in a short time, as much as 30% of the annual pollution load of motorway runoff waters.
Kinetics of Biological Phosphorus Release
Authors: Wentzel M. C. , Dold P. L. , Ekama G. A. , Marais G v. R.
Published: May 2018

Experimental observations indicate that the magnitude of biological excess P uptake is linked strongly to the magnitude of P release in the anaerobic reactor. A theory describing the kinetics of P release is presented in terms of the readily biodegradable COD in the influent, the non-polyP heterotrophic mass, the anaerobic mass fraction and the reactor flow regime. Observed P release conforms well to that predicted over a wide range of wastewater characteristics and process conditions.
The Readily Biodegradable Fraction of Sewage: Its Influence on Phosphorus Removal and Measurement
Authors: Nicholls H. A. , Pitman A. R. , Osborn D. W.
Published: May 2018

Various full-scale studies on the 5-stage Bardenpho process for biological phosphorus removal are reported with special reference to the role of readily biodegradable substrate in phosphorus removal. Results indicated that efficient denitrification was always a prerequisite for good phosphorus removal. The availability of fermencation products could greatly assist both nitrogen and phosphorus removal. Various options for the generation of these products are presented. Methods for the estimation of readily biodegradable substrates, of which fermentation products can be a component, are evaluated.
Changes in Particle Size Distributions on a Fixed Bed of Granular Activated Carbon
Authors: Shpirt E. A. , Alben K. T.
Published: May 2018

The particle size distribution at different bed depths of a fixed bed of granular activated carbon (GAC) has been monitored during 50 weeks of a pilot column run at the Waterford, New York potable water treatment plant. Initial backwashing resulted in significant stratification of GAC in the column: larger particles (average diameter 1.18 mm) settled in the bottom of the column (105 cm), and smaller particles (average diameter 0.97 mm) were concentrated near the top (24 cm), compared to samples of unstratified virgin Calgon F400 (average diameter 1.09 mm). During column loading and initial backwashing, more fines were created than were present in the virgin GAC (average 6.5% of GAC fines in the > 40 mesh fraction, compared to only 0.3% in the > 40 mesh fraction for virgin Calgon F400). After 50 weeks of service there was an overall trend toward a smaller average particle size (0.9 mm) with development of a more regular pattern of bed stratification (1.08 mm at the bottom and 0.75 mm at the top). These changes are attributed to breaking of large particles (12-20 mesh) and creation of intermediate size particles (20-30 and 30-40 mesh).
Effects of Water Reuse, Recycling and Resource Recovery on Food Processing Waste Treatment in Thailand
Authors: Frankel R. J. , Phongsphetraratana A.
Published: May 2018

Two food processing industries in Thailand, namely pineapple canning and tuna/sardine canning, were studied over a 10 year period to document effects of water reuse, recycling and resource recovery (both energy and product) on waste treatment needs and actual operations. Changes in terms of water consumed, energy required, waste generated, and costs per ton of raw material processed were calculated. Lower overall annual costs resulted from all water conservation and energy recovery schemes even though stricter pollution control laws were the motivating factor behind the changes. Unit design parameters of water use, energy use and waste load generated per ton of raw material processed are included for both industries to permit extrapolations for future waste treatment plant designs.
The Implications of the IAWPRC Hydrolysis Hypothesis on Low F/M Bulking
Authors: Ekama G. A. , Marais G v. R.
Published: May 2018

The IAWPRC hypothesis, that particulate biodegradable COD hydrolyzes to a readily biodegradable (soluble) form, introduces an additional source of readily biodegradable COD for which the floc-formers and filaments compete. Acceptance of this hypothesis requires a re-evaluation of the selection criterion for the growth of filaments or floc-formers proposed by Chudoba et al. (1973). An alternative selection criterion, and some experimental observations supporting it, are presented.
Evaluation of the General Activated Sludge Model Proposed by the IAWPRC Task Group
Authors: Dold P. L. , Marais G v. R.
Published: May 2018

This paper reviews the antecedents to the general activated sludge model proposed by the IAWPRC Task Group on modelling of the activated sludge system. Modifications to the Group model are proposed and sets of experimental data from a wide range of single sludge systems are presented to validate the model.
Systems and Solutions for Wastewater Treatment in the Biggest Yugoslav Oil Refinery
Authors: Legović B. , Nikolić O.
Published: May 2018

This paper aims at presenting the technology of wastewater treatment at the INA Oil Refinery of Rijeka applied in the past,and in the early eighties, when much stricter standards for their discharge into the sea developed a new approach to wastewater management.

The refinery of Rijeka, built in the middle of the sixties, was not designed with water economy and water treatment in mind : its water consumption was very high and the polluted and clean water streams were intermixed in the combined sewer system. This resulted in high wastewater flows and in high pollutant loads per ton of crude oil. Nowadays, the wastewater treatment programme includes in-plant control measures and a modern wastewater treatment plant.

The in-plant control includes the pretreatment of sour condensates and of the recirculating water, cool ing and collecting each category of wastewater in a separate sewer system. This modern wastewater treatment plant includes primary treatment, the thorough removal of emulsified oil and colloidal solids in the flocculation and flotation unit and the removal of dissolved organic materials by biological oxidation. The sludges are incinerated in a fluidized - bed type of incinerator.
Treatment of Olive Oil Waste Waters
Authors: Mendia L. , Carbone P. , d'Antonio G. , Mendia M.
Published: May 2018

Olive oil production is well distributed among the Mediterranean countries. Different levels of processing technology and different industrial organizations co-exist. The production cycle is seasonal and usually concentrated in the fall-early winter period. The pollution characteristics of this industry are peculiar because the flow rates are relatively small while the pollutant load is extremely high and difficult to abate because of the inherent characteristics of low pH and high concentrations of suspended matter, organic matter and lack of nutrients. The free disposal of such waste waters into the environment, though fairly common practice, has disastrous effects on the soil, on aquatic bodies, sewers and on urban waste water treatment plants. Factory specific pre-treatment is too complex and expensive to be realistically adoptable. A territory integrated solution strategy is therefore preferable and a few treatment schemes have here been presented. The recovery and exploitation of the by-products can be justifiable while a realistic consideration of the local realities must be kept in mind. Research is still required to improve and optimize some phases of treatment.
State of the Art Review: An Epidemiological Approach to the Health Effects of Wastewater Reuse
Authors: Shuval H. I. , Fattal B. , Yekutiel P.
Published: May 2018

The reuse of wastewaters for agricultural irrigation can be a means of reducing the pollution of surface waters including those in coastal areas used for bathing. The wastewater stream of a community carries within it the complete spectrum of pathogenic bacteria, viruses, protozoa and helminths which are endemic in the community. These pathogens can survive sufficiently long in the soil or on crops to infect, at least in theory, persons coming in direct contact. Thus, it is important to establish a sound epidemiological basis for health regulations related to the reuse of wastewater in agriculture. This paper presents the theoretical epidemiological considerations that should serve as the basis for a predictive model of the potential risks associated with wastewater irrigation. Empirical data from credible, quantifiable epidemiological studies have here been reviewed to validate the theoretical model. For developing countries, the authors have concluded that the ranking of pathogens as to the degree of risk associated with wastewater irrigation is as follows: high risk - helminths, medium risk - bacteria and protozoa and low risk - viruses.In order to effectively reduce the concentration of these pathogens wastewater treatment is recommended as the most effective control strategy.
Problems Associated with Particulate Matter in Water Reuse for Agricultural Irrigation and Their Prevention
Authors: Adin A.
Published: May 2018

Methods of irrigation are reviewed, including surface irrigation, sprinkler irrigation and drip irrigation, and the problems of these systems with regard to the quality of the water used are described. Surface irrigation does not suffer much from water quality problems, but both sprinkler irrigation and drip irrigation systems are more affected, the main problem being clogging of pumps, pipes and orifices. Clogging is usually due to a combination of suspended matter, chemical precipitation and biological growth. Current solutions through water treatment, and associated problems with this, are described, with examples given of typical strainers and filters. The key to the solution of clogging problems is a proper match between water quality of the source and within the distribution system, and the type ot treatment to be used, therefore, proper water quality monitoring is recommended. Direct granular filtration is the most preferaDle treatment process for drip irrigation systems.
Objectives and Achievements of the Three Conferences on the Protection of the Adriatic Sea
Authors: Kalpié A.
Published: May 2018

SUMMARY

Three of the conferences held so far on the protection of the Adriatic Sea (Opatija 1974, Hvar 1979 and Budva 1984) each in their own way gave their scientific, professional and social contribution to determining the existing conditions and future activities that should be undertaken in order to protect the human environment in the area of the Adriatic Sea. The objectives and achievements of each of these conferences have in this paper been presented on the basis of actual documents as well as taking into account the existing problems, programme and planned development. The paper also states what has been done so far on organizing the IV. Conference (1989) as one aspect of the work done on preventing pollution and undertaking efficient measures that would lead to a greater success in protecting the human environment through development in the area of the Adriatic Sea.
Reduction of Microbial Indicators and Viruses in a Cypress Strand
Authors: Scheuerman P. R. , Farrah S. R. , Bitton G.
Published: May 2018

The fate of bacterial indicators, bacteriophages and enteroviruses was studied in a forested cypress strand treated with primary effluent from the town of Waldo, Florida. Experimental corridors (40m × 10m) were installed in a strand and were treated with pumped primary effluent. Bacterial indicators (total and fecal coliforms, fecal streptococci), bacteriophages and enteroviruses, were removed following 40m travel of sewage through the corridors. The results indicated that fecal streptococci accumulate in the sediments.

The levels of bacterial indicators, phages and enteroviruses were monitored in another strand that had been receiving sewage for 50 years. Microbial numbers were determined at stations situated at increasing distances from the sewage outfall (up to 230m). It was observed that the bacterial indicators were reduced approximately by 3 log10 units at the 230m-station. Fecal streptococci were shown to accumulate in the sediments. The reduction in the number of phages was less and was approximately one log10unit. Enteroviruses and Salmonella spp. were detected in the cypress strand water. They were often undetectable in the sediments.

The results demonstrate the potential use of wetlands for low-energy treatment of sewage effluents.
The Removal of Excreted Bacteria and Viruses in Deep Waste Stabilization Ponds in Northeast Brazil
Authors: Oragui J. I. , Curtis T. P. , Silva S. A. , Mara D. D.
Published: May 2018

The removal of excreted bacteria (faecal coliforms, faecal streptococci, Clostridium perfringens, total and sorbitol-fermenting bifidobacteria, salmonellae and thermophilic campylobacters) and viruses (enterovirus and rotavirus) in a series of deep anaerobic, facultative and maturation ponds (depth range: 2.8 - 3.4 m), with an overall retention time of 21 days and a mean mid-depth temperature of 27°C, was studied. Thermophilic campylobacters, bifidobacteria and salmonellae were not detected after 11, 16 and 21 days' retention respectively. Faecal coliforms, faecal streptcocci and Cl. perfringens were reduced by 4, 4 and 2 orders of magnitude respectively, and enteroviruses and rotaviruses both by 3 orders. The results indicate that pathogen removal in deep ponds is similar to that in ponds of normal depth.
Survival and Transport of Hepatitis a Virus in Soils, Groundwater and Wastewater
Authors: Sobsey M. D. , Shields P. A. , Hauchman F. H. , Hazard R. L. , Caton L. W.
Published: May 2018

Hepatitis A virus (HAV), poliovirus type 1 and echovirus type 1 were studied for their adsorption and survival in groundwater, wastewater and soils suspended in these media and for survival and transport through unsaturated miniature soil columns intermittently dosed with virus-laden groundwater or wastewater. There were differences among the viruses in adsorption to soils, with poliovirus adsorbed most extensively, echovirus the least and HAV intermediate between these two. All three viruses survived well (>90% inactivation) for at least 12 weeks in groundwater, wastewater and soil suspensions at 5°C. However, at 25 C, HAV survived generally longer than poliovirus and echovirus, with 90–99% inactivation of HAV and 99.9–99.99% inactivation of poliovirus and echovirus in 12 weeks. In miniature soil columns dosed with virus-laden groundwater or wastewater, virus reductions were generally least for echovirus and greatest for poliovirus. HAV reductions were intermediate between these two, but more like poliovirus. The ability of HAV to survive for long periods in soils, groundwater and wastewater and to migrate to some extent through unsaturated soils helps to explain why HAV can contaminate groundwater and cause outbreaks of groundwaterborne disease.
Virus Adsorption to Microporous Filters Modified by in situ Precipitation of Metallic Salts
Authors: Toranzos G. A. , Erdos G. W. , Farrah S. R.
Published: May 2018

Microporous and depth filters composed of fiberglass, cellulose, and nitrocellulose were placed in solutions of soluble metallic salts such as ferric chloride. Following adsorption of the soluble salt, the filters were allowed to dry and then placed in a solution of sodium or ammonium hydroxide. This resulted in the formation of stable precipitates in and around the fibers of the filters. Filters modified by this procedure of insitu precipitation adsorbed significantly more viruses than untreated filters. Filters modified by the insitu precipitation of combinations of salts such as ferric and aluminum or magnesium generally were better virus adsorbers than filters modified by the precipitation of a single salt.
Microbial Indicators for the Efficiency of Disinfection Processes
Authors: Kawamura Kiyoshi , Kaneko Mitsumi , Hirata Tsuyoshi , Taguchi Katsuhisa
Published: May 2018

Fundamental studies have been conducted to find new microbial indicators for the effective inactivation of micro-organisms resistant to disinfectants and UV irradiation. Escherichiacoli, Salmonella typhimurium, Staphylococcusaureus, Candidatropicalis and spore-forming bacteria (isolated from sewage) were exposed to free chlorine or free ozone at concentrations in the range 10−2 to 100 mg/l, and 253.7 nm UV at light intensity levels of 101 to 103µW/cm2. For all disinfectants examined, the relation cn·t = const., where c is the disinfectant concentration and t the contact time for 99% reduction of microorganisms, was found to be valid. The order of resistance was about the same in all cases and was as follows: spore-forming bacteria » C.tropicalis » Staph.aureus,E.coli,S.typhimurium. However, at the same disinfectant concentration, the contact time required to obtain the same inactivation efficiency was reduced effectively by ozone. UV light inactivates spore-forming bacteria and C.tropicalis more effectively than chlorine, although the intensity of UV light and the concentration of chlorine studied have similar effects on E.coli. These results are compared with results for viruses already obtained by other researchers. Spore-forming bacteria may be the ideal micro-organisms to evaluate the completeness of disinfection, but they require a long contact time to be inactivated by chlorination. However, when ozonation or UV irradiation is used as the method of disinfection, spore-forming bacteria can be used as an indicator, because they are then inactivated under usual field conditions in contact or irradiation time.
Prospective Epidemiological Study of Health Risks Associated with Wastewater Utilization in Agriculture
Authors: Fattal B. , Yekutiel P. , Wax Y. , Shuval H. I.
Published: May 2018

A prospective epidemiological morbidity and aerology study was carried out in Israel in 1980/82 on the association between enteric disease incidence and wastewater utilization in 29 kibbutzim - collective agricultural communities (population 15 605).

Analysis of morbidity data indicates that no significant excess of enteric disease episode rates was found in any age group, including the 0-5 year old age group, or in any occupational group, in kibbutzim exposed to wastewater aerosols versus kibbutzim using wastewater but not exposed to aerosols, or kibbutzim not exposed to wastewater in any form.

Results of viral antibodies in blood sera of a subsample of the population generally confirmed the findings of the morbidity study. Of 8 enteroviruses tested no excess in antibody level was found in the population, exposed to aerosolized wastewater versus the control kibbutzim. However, a consistent and significant excess of prevalence for ECHO 4 virus antibodies was found in the 0–5 year old age group in kibbutzim exposed to aerosolized wastewater from nearby towns as compared with all other populations (p<0.001). No excess of morbidity was detected, however, in this group.

A significant excess in the percentage of sera positives was found for Legionella pneumophila (serogroup 1–8) among all water contact workers versus nonwater contact control group workers (4.5% vs 1.5%). However, no differences were found between waste water-contact and clean water-contact workers.

In field studies, aerosolized enteric bacteria and viruses of wastewater origin were detected in air samples as far as 730 m downwind of wastewater sprinkler irrigated plots.
Microbiological Content and Health Effect of Fishponds Enriched with Wastewater Effluent
Authors: Guttman-Bass N. , Noe N. M. , Fattal B.
Published: May 2018

During July to December 1980, a study was carried out on kibbutzim (cooperative agricultural settlements) in Israel, to determine the microbiological quality and health effect of fishponds enriched with human wastewater. Ponds on seven kibbutzim were sampled, two of which were chosen for intensive study: one (B231) used domestic wastewater effluent as a fish pond supplement, while the other (C252) used only animal wastes as a supplement.

Thirty-eight (38) water samples were assayed for total and fecal coliform. The use of wastewater in the ponds did not consistently increase the levels of the indicator bacteria, in comparison with unenriched ponds. Fish were assayed for coliform and fecal coliform levels in their intestinal tracts and muscle tissue. No consistent difference was found as a result of wastewater enrichment.

Salmonella strains were isolated from ponds or fish not exposed to human wastewater, while enteroviruses (poliovirus) were isolated from water from a pond enriched with human wastewater.

Analysis of morbidity data showed no significant excess in enteric disease rates among the total population or among fishpond workers on kibbutzim using wastewater for fishpond enrichment, in comparison with kibbutzim not using human wastewater in their fishpond.
Detection of Cryptosporidium from Wastewater and Freshwater Environments
Authors: Rose J. B. , Cifrino A. , Madore M. S. , Gerba C. P. , Sterling C. R. , Arrowood M. J.
Published: May 2018

Cryptosporidium is a coccidian protozoan and has recently been recognized as a cause of human gastroenteritis. The illness may be severe in immunocom-promised individuals and can result in death. The organism is monoxenous, and infective oocysts are shed in the feces, which are transmitted via the fecal-oral route. Therefore, Cryptosporidium may be a possible candidate as an etiological agent of waterborne or foodborne disease. Previously, the lack of methods for detection of this organism in diarrheal samples as well as environmental samples, has made it difficult to substantiate this premise. Detection of Cryptosporidium oocysts in water has now been accomplished using a filtration-elution procedure. A fluorescently-labelled monoclonal antibody which has been used for the detection of Cryptospori di urn in feces was also used to detect the oocysts in environmental samples.

The method developed for detection of Cryptosporidium in water including: 1) filtration with polypropylene cartridge filters, 2) elution with Tween 80/detergent, 3) concentration with Sheather's flotation, and 4) detection on membrane filters, was evaluated and used to examine wastewater and fresh water for Cryptosporidiurn oocyst concentrations. Recovery from the sucrose gradient step averaged 72 – 82%. Overall recovery efficiencies ranged from 25 – 82% (average 50%), but were diminished with low seeds. Concentrations were found in ranges from 60 to 52,000 oocysts/gal in treated and raw sewage. In fresh water, oocysts numbered 8 to 22,000/gal and were concentrated in rapid sand filters averaging 59,000/gal in the backflush. Cryptosporidium may now be considered a potential waterborne parasite.
The Utilization of Plastic Pipe for Submarine Outfalls – State of the Art
Authors: Lars-Eric Takeshi
Published: May 2018

During the last 25 years, a great number of submarine pipelines have been built in Scandinavia. They are all a result of intensive activity in the field of environmental control, the consequence of which has often been that the last purification step in the wastewater treatment process has been considered to be the dilution of the residual waste into the ocean. Efforts have been made to develop a new piping technology which would allow great depths and points situated far off-shore to be reached, where the risk of problems due to floatable materials flowing back to the shore is insignificant. It has been regarded as especially essential to find a technique which would enable a cheap and rapid procedure for pipe submersion even far off-shore and in heavy sea conditions. The reason for this is that a major proportion of the cost of a submarine pipeline relates to submersion work. Additional requirements were that the pipe material should withstand sudden and even exceptional wave forces and also permit uneven settlements as well as movement of sediment on the sea bed. Thus, the aim has been to develop a highly flexible pipe.

The paper presents the state of the art by referring to a submarine outfall project implemented in Sweden 1985. Some need for further development is also discussed.
Criteria for the Utilization, Design and Operation of UASB Reactors
Authors: Souza M. E.
Published: May 2018

This paper describes and discusses the principal ideas and parameters related to the application, design and operation of wastewater treatment systems using the upflow anaerobic sludge blanket reactor (UASB). The differences in the process brought about by the high or low concentration of organic material in the wastewater to be treated are pointed out in each consideration.

The purpose of this paper is to make the development of simple, but safe and efficient UASB reactor treatment units, by technicians not necessarily highly specialized in the subject, possible. It also attempts to point out problems which are not yet completely solved in order to help in the preparation of future research and development plans.

A number of possible questions that deal with the following subjects are discussed:–types of waste which can be treated by the UASB reactor–concentrated wastes (for example, stillage from sugar-cane) and diluted wastes (for example, domestic sewage)–necessity of pre- and post-treatment–temperature–shape and dimensions of the reactor–criteria and details for design–start-up, operation and control of the unit–forecasts of efficiency, costs, etc.
Anaerobic Wastewater Treatment in the Food Processing Industry: Two Case Studies
Authors: Campos J. R. , Foresti E. , Camacho R D. P.
Published: May 2018

This article relates two experiments with wastewater treatment in the food processing industry. One of them refers to the use of an anaerobic filter (meat processing industry) and the other to the use of an upflow anaerobic sludge blanket reactor-UASB (vegetable and fruit processing industry). In the first case, the study describes the performance of an anaerobic filter which has been working for 6 years and provides COD removal efficiency (including primary treatment) equal or better than 80% with an organic loading of 1.4 kg of COD/m3 day. The reactor has a bed of broken stones with size of 0.75 m having a medium hydraulic detention time of 13 h. Discharges of accumulated sludge in a false bottom below the filter are made at intervals of 2 or 3 months.In the second case, the study describes the performance of an upflow anaerobic sludge blanket reactor (88 m3) during 255 days of operation including the adaptation phase or startup. This reactor receives wastewater from vegetable and fruit processing including tomato , corn, guava and peach. At the end of each operational phase studied, the COD removal efficiency was about 80%. In the last phase (7.5 h hydraulic detention time), the organic loading was 1.4 kg of COD/m3 day and the hydraulic loading was 3.2 m3/m3 day.
Advanced Reactor Design, Operation and Economy
Authors: Lettinga Gatze , Pol Look Hulshoff
Published: May 2018

Of the high rate anaerobic wastewater treatment systems the UASB (Upflow Anaerobic Sludge Blanket) reactor has found the widest application. Therefore the attention with respect to design, operation and economy will be focussed on this reactor type.

In designing a UASB reactor specific attention is needed for the GSS (Gas-Solids Separator) device and the feed inlet system.

For soluble wastewater generally no phase separation is required. Only for wastewaters high in suspended solids pre-acidification in a separate acidification reactor can be beneficial. Increasing attention is given to the development of modified UASB systems, such as a combination of a sludge bed reactor and an anaerobic filter.

Other possible modified UASB systems may be found in a FS (Floating Settling) UASB reactor, the EGSB (Expanded Granular Sludge Bed) reactor and the UASB IC (Internal Circulation) reactor. As many factors are involved in the costs of a UASB reactor, only some rough data on reactor costs are presented.
Anaerobic Digestion of Municipal Solid Wastes
Authors: Schmidell W. , Craveiro A. M. , Peres C. S. , Hirata Y. S. , Varella R. F.
Published: May 2018

This paper discusses the present state of municipal solid waste (MSW) disposal in Brazil , focusing on the particular situation in the City of Sao Paulo, and indicates the future trend of the anaerobic digestion approach for this residue. Also, some results, representative of several studies developed at IPT on anaerobic digestion of MSW mixed with primary sewage sludge, are presented. These studies were conducted using agitated reactors of 2 or 8 liters capacity, continuously operated at 35°C and in the pH range 6.8 to 7.2. The studies were on: start-up of reactors, MSW to sewage sludge ratio, organic loading rate and hydraulic retention time. The results presented in this paper indicate the great interest in achieving anaerobic digestion of MSW in presence of sewage sludge, utilizing reactors with high solids content, which is the approach already observed, and certainly will be developed in the future.