bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on the Seasonal Variation of Surface Sediment Composition in Estuaries
Authors: Kawara O.
Published: May 2018

The purpose of this study, as the first step toward clarifying the pollutant transport mechanism of sediments, is to clarify the characteristics of the seasonal changes of surface sediment composition in estuaries based on observation. Remarkable seasonal variations are found in the particle size distributions and the concentrations of the constituents of the surface sediments, though the patterns of the variations are different in each estuary observed. The seasonal variations of the concentrations show good correspondence to those of the particle size distributions. One cause of the seasonal variation is the variation of river discharges. When the sediment size in the Asahi River estuary, Okayama prefecture, became finer, the fresh water inflow to the estuary was about 2.5-3.5 times as much as ordinary water runoff (100-150m3/s) and the change was completed in about 10 days. On the other hand, the change to coarser sediment was completed in a day, by the inflow of over 400m3/s.
Resuspension of Sediments from Long Island Sound (U.S.A.)
Authors: Tsai Cheng-Han , Lick Wilbert
Published: May 2018

Resuspension experiments were conducted in sea water in an annular flume on fine-grained sediments from Long Island Sound. From these experiments, the resuspension rates and the sediment concentrations at steady-state were quantitatively determined as a function of shear stress and bed compaction. In addition, net resuspension experiments were conducted. From these, the total amount of sediment that could be resuspended at a particular shear stress was determined. In these tests, the resuspension rate decreased with time and the total amount of sediment that could be resuspended at a constant shear stress approached a constant value as time increased. This demonstrates a major difference between the resuspension characteristics of fine-grained sediments and those of uniform-size, coarse-grained, non-cohesive sediments. For the latter case, the resuspension rate ideally would be constant with time.

Resuspension experiments were also conducted with deposit-feeding Nucula clams seeded into the sediment bed. In all cases, the steady-state concentrations as a function of shear stress were significantly greater than those in tests without Nucula. The tests also suggest that after sediments are seeded with Nucula for approximately 7 days, the sediment resuspension does not change with time of consolidation.
Effect of Salinity on Nitrification in a Tidal River
Authors: Furumai Hiroaki , Kawasaki Takashi , Futawatari Tohru , Kusuda Tetsuya
Published: May 2018

Several field surveys were conducted to investigate changes of water quality with time in the tidal River Rokkaku, where a turbidity maximum exists. Suspended solids of the turbidity maximum reach more than 20 g/l in concentration. Based on the surveys, NH4-N, NO2-N, and NO3-N have peaks in concentration at certain salinities, located in order of NH4-N, NO2-N, and NO3-N toward the river mouth within 10 to 25 km from it. The salinities were 0.5, 1.7, and 3.0 %, respectively, and the maximum concentrations were about 3.0, 0.3, and 4.5 mg/l in winter time, respectively.

Laboratory batch experiments were conducted, using suspended solids and sediments taken from the river, to study the effect of salinity on nitrification and to estimate kinetics parameters of it in the river. Suspended solids and sediments were sampled at a point in the middle stream. The sediments were collected from the aerobic layer of mud, less than 1 cm thick from the surface. Experimental results indicated much more inhibition of NO2 oxidation by salinity than that of NH4 oxidation. Nitrifying bacteria in sediments were less sensitive to salinity than those in suspended solids. The change of nitrogen concentration with time was clearly explained with the Monod growth model and the two kinetics parameters were obtained by the curve fitting method. Maximum specific growth rates of NH, oxdizing bacteria ranged from 0.015 to 0.029 (hour−1), which decreased markedly with more than 15 %. salinity. Those of NO2 oxidizing bacteria ranged from 0.015 to 0.025 (hour). Saturation constants of NH4 and NO2 oxidation were also dependent on salinity. Changes in NH4-N and NO2-N concentrations in the River Rokkaku with time were simulated well using a newly developed river model and the parameter values obtained in the laboratory tests. The mechanism of nitrification by suspended solids and sediments in the river is shown to depend on tidal effects.
Strategies for Coastal Water Quality Management: A Case Study of Laem Chabang (Thailand) Deep-Sea Port Development
Authors: Muttamara Samorn , Baldisimo Julito M.
Published: May 2018

An environmental study was conducted as a part of coastal water quality management for Laem Chabang Deep-Sea Port. It was revealed that the existing seawater quality at Laem Chabang area is generally well within standards for unpolluted seawater, making it suitable for fishing and recreation.

Environmental impact assessment of the different activities to be carried out in relation to the Laem Chabang port development indicated that the following significant impacts on the marine environment can be anticipated: (1) direct damage to biological organisms by resuspension of organics due to disturbance of marine habitat during dredging/reclamation and breakwater/pier construction; (2) creation of high turbidity by disposal of dredge spoil which disturbs and/or smothers marine flora and fauna and, more importantly, poses the greatest threat to the tourism industry in Pattaya located about 12 km from the project site; (3) modification of the tidal current direction and velocity in the Laem Chabang bay as a result of dredging in the entrance channel, fairway and basin; (4) deterioration of seawater quality due to discharge of tapioca powder losses, domestic wastewater from port area and sewage from ships (5) destruction of the aesthetic aspects of the port waters and surrounding areas as a consequence of solid waste generation from cargo handling from ships.

A number of strategies/measures for coastal water quality management to prevent or minimize the adverse impacts have been recommended. The proposed environmental protection program is necessarily justified considering the economic benefits to be gained by the country from port operations.
Chemical Ecology and Off-Flavour Substances
Authors: Skulberg O. M.
Published: May 2018

Off-flavour substances may be regarded as a resource which can be used to study special ecological mechanisms. Relevant research on off-flavours is inextricably combined with the study of perception, ethology, genetic control etc. The chemicals concerned are commonly perceived by the senses of olfaction and gustation. Thus research on the chemical ecology of off-flavour substances in the aquatic environment involves the study of a variety of disciplines. For example the biochemistry of the relevant substances and appropriate metabolic pathways must be considered. Chemical properties are important for the behaviour of the substances. The production of off-flavours by organisms is related to phenological circumstances. The biotic effects of ecologically significant substances are dependent on several environmental factors. This paper draws attention to the possible application of fundamental research in this area to selected problems of ecological importance.
Occurrence of Musty Odor in the Yodo River
Authors: Hishida Y. , Ashitani K. , Fujiwara K.
Published: May 2018

Geosmin and 2-methylisoborneol (MIB) for the past seven years have been responsible for the occurrence of musty odors in Lake Biwa. These odorous compounds are present in the water either in solution or in a form attached to or sited in the body of the responsible cyanobacteria. The concentration of geosmin was found to decrease during its passage through the river. However, MIB was not affected. During the water shortage period of the summer of 1985, the concentration of geosmin was found to increase downstream of the Yodo river. This was attributed to a regrowth of Anabaenamacrospora caused by stagnation of the water in this region.
Formation and Removal of Off-Flavour Compounds during Ozonation and Filtration through Biologically Active Sand Filters
Authors: Lundgren B. V. , Grimvall A. , Sävenhed R.
Published: May 2018

Formation and removal of off-flavour compounds during ozonation and during filtration through biologically active sand filters have been evaluated by gas chromatography and column sniffing. A well aerated sand filter (0.5 m deep) with a water flow rate of 25 mm/h was able to produce an almost odourless water from a raw water with a strong muddy and earthy off-flavour. Frequently occurring off-flavour compounds, such as geosmin, 2-methylisobomeol, 2,4,6-trichloroanisole, 1-octen-3-one and dimethyl trisulphide, were all effectively removed, provided the oxygen supply was sufficiently high. The removal of colour, however, was not satisfactory. Treatment with ozone removed the colour of the water and caused a dramatic change in odour quality. Certain off-flavour compounds, such as geosmin and 2-methylisobomeol, decreased in concentration, while several other off-flavour compounds, such as octanal, increased in concentration. The ozonation by-products were only partly removed during sand filtration, and the filter effluent had a weak, but noticeable, off-flavour. Chromatographic sniffing indicated that some of the ozonation by-products were, in fact, less amenable to biodegradation than the off-flavour compounds that were removed by ozonation.
The Diversity of Activated Sludge Microbial Communities as Described by the Fundamental Niche Concept
Authors: Simpkin Thomas J.
Published: May 2018

The fundamental niche concept provides a means of describing the structure and diversity of an activated sludge microbial community. The concept explains community diversity by describing the many traits of each microorganism species and how these traits may or may not be involved in providing the mechanism for the specie to proliferate in a given environment. This paper develops the concept of the fundamental niche as it relates to activated sludge communities. The ability to denitrify is provided as an example of how the concept may be used to explain the proliferation of denitrifying microorganisms under non-denitrifying conditions.
Biodegradation of Carbamates
Authors: Rasul Chaudhry G. , Wheeler W. B.
Published: May 2018

A carbofuran-metabolizing Pseudomonas sp. was investigated for its capability to degrade some other toxic carbamates and its effectiveness as a decontaminant for carbamate-polluted water samples. The organisms degraded both aldicarb and carbaryl. It also decontaminated carbofuran-fortified water samples from various sources in the absence of additional nutrients under laboratory conditions. This microorganism harbored several plasmids which may be involved in the degradation of carbamates. Pseudomonas sp. may potentially be used for biological treatment of wastewater and groundwater.
Activated Sludge Treatment of Ethoxylate Surfactants at High Industrial Use Concentrations
Authors: Salanitro J. P. , Langston G. C. , Dorn P. B. , Kravetz L.
Published: May 2018

The primary degradation of a linear alcohol ethoxylate (AE) and a branched nonylphenol ethoxylate (NPE) was investigated in bench-scale activated sludge units treating a synthetic sewage feed. Biotreaters were gradually adapted to 10-100 mg/ℓ surfactant and effluents monitored for loss of nonionic ethoxylate, foaming, feed BOD removal, nitrification and biosolids growth. Both surfactants were degraded at influent doses of 10-40 mg/ℓ. Substantial BOD breakthrough, loss of nitrification, aerator foaming and incomplete removal of the NPE surfactant occurred when fed at 80 and 100 mg/ℓ while the unit treating AE was unaffected by high surfactant levels. Comparative aquatic toxicity of the biotreated waste at high surfactant levels indicated that the NPE effluent was acutely toxic (EC50, 7-15% effluent) to the fathead minnow and Daphnia while that of the AE unit was non-toxic (EC50, > 100% effluent) to these same species. These studies indicate that the treatment of wastes containing high levels of NPE ethoxylates may adversely impact an activated sludge process in incomplete degradation and foaming, impaired BOD removal, loss in nitrification and the formation of toxic effluents. AE surfactants, however, undergo extensive microbial degradation and cause little or no impact on the activated sludge treatment process.
Kinetics of Methane-Oxidizing Biofilms for Degradation of Toxic Organics
Authors: Strand S. E. , Seamons R. M. , Bjelland M. D. , Stensel H. D.
Published: May 2018

The kinetics of methane-oxidizing bioreactors for the degradation of toxic organics are modeled. Calculations of the fluxes of methane and toxic chlorinated hydrocarbons were made using a biofilm model. The model simulated the effects of competition by toxics and mediane on their enzymatic oxidation by the methane monooxygenase. Dual-competitive-substrate/diffusion kinetics were used to model biofilm co-metabolism, integrating equations of the following form:where S1 and S2 are the local concentrations of methane and toxic compound, respectively, and r and K are the maximum uptake rates and Monod coefficients, and x is the distance into the biofilm.
Protozoa and Metazoa as Indicators of Effluent Quality in Rotating Biological Contactors
Authors: Kinner N. E. , Curds C. R. , Meeker L. D.
Published: May 2018

In situ biofilm, incubation slide and freezing techniques were used to investigate the diversity of protozoan and metazoan populations inhabiting rotating biological contactor (RBC) biofilms in relationship to effluent quality during different seasons of the year at two treatment plants. The insitu biofilm techniques yielded the best results primarily because samples contained higher numbers of individuals per species and were easier to obtain. A protocol based on 2 microscopic scans (200x magnification) across a total width of a covership on each of 3 slides is proposed as a cost-effective procedure for discriminating among three classifications of effluent quality (Good: BOD5 ≤ 25 mg/l, Fair: BOD5 - 26 to 40 mg/l Poor: BOD5>40 mg/l) based on the populations of organisms inhabiting RBC biofilms.
Comparative Studies on the Survival of Indicator Organisms and Pathogens in Fresh and Sea Water
Authors: Evison L. M.
Published: May 2018

Results are reported from a comprehensive series of experiments in which the survival characteristics of a range of indicator bacteria, pathogenic bacteria and bacteriophages was compared in fresh and seawater in the light, and at a range of temperatures, nutrient concentrations and salinities in the dark. Survival of the following organisms was studied: E.coli, faecal streptococci, maroon faecal streptococci, Salmonellatyphimurium 12, 12a and 110, S. anatum, Shigellasonnei, Sh. flexneri, Yersinia enterocolitica, Campylobacter fetus, Coliphages MS 2 and f 2. The data shows that in the light the survival of E.coli was very poor compared to that of Salmonellae. In the light, survival was best in fresh water, but in the dark survival in seawater was usually better. A linear relationship was demonstrated for T,90 and light intensity, and log T90 and temperature, but non-linear responses occurred for a range of salinities and nutrient concentrations.
Disinfection, Recontamination and Regrowth of Indicator Bacteria in a Wastewater Sludge Heat Treatment System
Authors: Fujioka Roger S. , Hirano Wesley M. , Loh Philip C.
Published: May 2018

The largest sewage treatment plant in Hawaii produces 25,400 kg/day of primary sludge that is heat-treated (190°C) under 330 psig for 3 0 min. Although this treatment should result in a sterilized sludge product, the final sludge cake often contains high concentrations of fecal-borne indicator bacteria. The heat-treatment process was shown to disinfect the sludge of indicator bacteria. However, post contamination of the heat-treated sludge by raw sludge and by chlorinated primary effluent and the regrowth of indicator bacteria in the sludge storage tanks resulted in the presence of indicator bacteria in the sludge cake.
The Behaviour of Chlorinated Organics during Activated Sludge Treatment and Anaerobic Digestion
Authors: Kirk P. W. W. , Lester J. N.
Published: May 2018

An activated sludge pilot plant was operated at 4,6 and 9d sludge ages with influent settled sewage from a full scale treatment works. The behaviour of the chlorinated organic micropollutants was examined at their background levels in sewage and significant removal was seen for dieldrin, Y-HCH, DDE, PCB and 2,4-DCPol at all sludge ages. Dieldrin, Y-HCH, DDE PCB, 2,4,5-TCPol, 2,4,6-TCPol and 2,4-DCPol were found to associate with activated sludge solids. 2,4-DCPol and 4-C-2MPol were found to be biologically degraded. Mixed primary sludge from the same sewage treatment works was incubated anaerobically with and without azide addition to prevent biological activity. Rapid removal of Y-HCH was concluded to be due to chemical degradation, while biological activity was concluded to be the mechanism for the removals of 2,4-D, 2,4,5-T, 2,4,6-TCPol and 2,3,4,6-TeCPol. Statistically significant increases were observed for 2,3,4,6-TeCPol in azide treated incubations and for 2,4,5-TCPol and 2,4-DCPol in both treated and untreated anaerobic sludges.
Fixed Biomass Activity in Aerobic Biological Reactors Used for Wastewater Treatment
Authors: Block J. C. , Nouvion N. , Cahen J. M. , Lesty Y. , Faup G. M.
Published: May 2018

Experimental runs were carried out on an upflow fixed-bed reactor. The process cycle of 24 hours was determined by following head losses used as an indicator of the clogging of the filter and of the biomass growth. Thanks to a protocol of dispersion of the biomass present into the filter, two fractions defined as fixed and shared biomass were obtained. The specific dehydrogenase activities or the specific oxygen uptake rates of the dispersed biomass were always greater than those of the fixed biomass. The aggregation of the biomass into the reactor prevents its potential activity being used to the full.
Small Sewage Treatment Plants and Wastewater Reuse in Cyprus
Authors: Larcou A. , Hadjivassilis I.
Published: May 2018

Due to the lack of central sewerage systems small wastewater treatment plants have been installed, mainly in coastal tourist areas of the island. The plants consist of a secondary and tertiary treatment by double filtration. The treated water after the tertiary treatment is used for irrigation purposes.
Treatment of Wastewater Containing Oil
Authors: Mavrov V. , Dobrevski I. , Peneva V. , Rashkov S. , Stathopoulos N.
Published: May 2018

The possibilities for treatment of a wastewater containing 120 - 170 mg/l of oil, with a COD of 190 - 312 mg O2/l and a pH of 7 - 7.6, were studied. A treatment process consisting of coagulation and adsorption was investigated. The effectiveness of coagulation using aluminium sulphate, ferric chloride, and aluminium chloride, was examined, and for the adsorption process, three activated carbons (A, B, and C) were considered. Carbons A and B were new types of activated carbon based on different pyrolysed brown coals, and carbon C was a commercial activated carbon. It was established that the optimum results were achieved by coagulation with 140 mg/l aluminium chloride (Al2(OH)5Cl), which produced a treated effluent with an oil content of 11 - 12 mg/l, followed by adsorption using activated carbon A, which gave a treated effluent with an oil content below 2 mg/l. Carbon. A could treat up to 2200 bed volumes of water before regeneration of the activated carbon was necessary.
Analytical Chemistry of Organic Compounds Present in Water
Authors: Junk Gregor A.
Published: May 2018

This report is a general overview of trace organic analysis as it relates to the contamination of water. The overview includes discussions of the history of the determination of trace levels of organic compounds and the important instruments used currently to make these determinations. Data from three past studies of water pollution are used to provide a better perspective of the possible effects of water contamination. The present status and future directions for the determination of trace levels of organic compounds present in water are also proposed.
Mercury Fixation in Contaminated Sediments as a Management Option at Albany, Western Australia
Authors: Schulz R. S.
Published: May 2018

Water overlying mercury contaminated sediments in Princess Royal Harbour, Albany, was found to contain up to 0.8 µg/L of mercury. Using contaminated sediments and water from Princess Royal Harbour experiments were carried out to remove the mercury from the waterbody and fix it to the sediment. Treatment with metallic iron reduced the mercury concentration of the water to less than 0.1 µg/L within 2 minutes and any potential visual pollution from the oxidation of iron was prevented by a sand overlay. The sand did not interfere with the lasting effectiveness of the iron.

A field trial was conducted to test the system under wind and tidal conditions in shallow waters of Princess Royal Harbour. It was established that due to the sedimental rework, the overlay thickness would have to be increased for the shallow waters. For deeper waters (>2 m), the system is expected to give good results over sand bottoms. Seagrass covered areas are expected to yield staining problems due to ineffective sand overlay.
Management of Recreational Water Quality in Estuaries and Coastal Waters – An Integrated Strategy
Authors: Fiddes D. , Lack T. J.
Published: May 2018

Major programmes are being undertaken in UK coastal areas to reduce the environmental impact of sewage discharges to estuarial and coastal waters. A particular requirement is compliance with the European Communities Bathing Water Directive: experience has shown that cost-effective environmentally acceptable schemes can be designed incorporating long sea outfalls but only if all major sources of pollutant loading are considered concurrently and sewer, river and marine modelling techniques and standards harmonised. To develop this integrated approach, the UK Water Industry has mounted a major research programme. The resulting procedure is described and the concept of use areas and associated quality standards introduced. The need for regular performance monitoring of outfalls is stressed and appropriate equipment described.
Water and Wastewater Treatment for a Small Island Resort
Authors: Rigden B.
Published: May 2018

The design of a reverse osmosis desalination unit and a rotating biological contactor for water and wastewater treatment for a small island resort is described. Some operational data are presented and recommendations for design flows and loadings are made.
Impact of Catchment Urbanisation on Lake Macquarie (Australia)
Authors: Simmons B. L. , Trengove S. L.
Published: May 2018

Increasing urbanisation of coastal areas is leading to impacts on coastal lakes which decrease their amenity for recreation and tourism. Runoff and wastewater discharge cause siltation, impact seagrass beds and change the characteristics of open waters, affecting boating, swimming, fishing and the aesthetic quality of the locale. Management of urban development and wastewater disposal is required to minimise sedimentation and nutrient enrichment. This could include development restrictions, runoff controls and a strategy for wastewater treatment and discharge.

The catchment of Lake Macquarie, a marine coastal lake, has been progressively urbanised since 1945. Urbanisation, through increased stormwater runoff and point source discharges, has caused a major impact on the lake in terms of sedimentation and nutrient enrichment. Losses of lake area and navigable waters have occurred. Accompanying problems include changes in the distribution of seagrass beds and nuisance growths of benthic algae. Since the 1950's, dry weather nutrient concentrations have increased and mean water clarity has decreased.

Severe problems, as observed in other New South Wales coastal lakes, for example benthic algae in Lake Illawarra and Tuggerah Lakes, have not yet developed. Because of the lead time taken to implement policies and controls, trends should be identified and policies developed now so as to avoid nutrient buildup and development of sustained problems.
Wimmera River (Victoria, Australia) – Increasing Use of a Diminishing Resource
Authors: Campbell Lachlan
Published: May 2018

The Wimmera River is central western Victoria's most important river, rising in the Grampians National Park, filling storages that supply the major water supply to the vast Wimmera and Mallee regions. It passes through the Little Desert National Park, an area of significant scenic, recreation, historical and conservation value and terminates in Victoria's largest inland freshwater lakes (Lakes Hindmarsh and Albacutya). The brittleness of the whole closed Wimmera River system, and the over committal of the water resources was brought to the public's attention when appeals were lodged against the proposal to licence a discharge of high standard secondary effluent from an extended aeration oxidation ditch and lagoon treatment facility at Horsham. Residents, user and community groups, Municipal Councils and Government Departments, aware of the deterioration of the Wimmera River had somewhere to focus their attention. Victoria's and possibly Australia's longest environmental appeal, lasting twenty-five days, and a State Environment Protection Policy, determined that all major point sources of nutrients should be removed from the River. More resources for clearing of unwanted emergent weeds, more facilities for protection of Crown Land and catchments generally, and the implementation of environmental summer flows as piping of the Wimmera-Mallee Stock and Domestic System proceeds, are all required. A River Management Board with strength, wealth, good public relations and a dedication to the task could make the Wimmera River an example for all Australia and a tourist attraction of immense value to the region.
Viruses in River Water and Health Risk Assessment
Authors: Walter Renate , Kaupa H. , Johl Margrit , Dürkop Jutta , Krämer Ursula , Macht W.
Published: May 2018

The construction of the Marchfeldkanalsystem (Austria) creates irreversible environmental changes which could have an impact on environmental health. Virological investigations of the river Danube have been carried out as a part of the environmental impact assessment procedure. The repeated detection of viruses in 61% of all water samples with a mean level of 0.762 MPN/l suggests that a permanent viral contamination of Danube is occurring and that the self-purifying capacity of the river is relatively inefficient. Strains of some virus families not hitherto detected in water (toga-(bunya) viridae) could be found. Provided the proposed treatment facilities are as effective as to remove the virus load to an extent of 99.99% the Marchfeldkanalsystem project will not endanger public health.
Development of Filtration/Adsorption Media for Removal of Bacteria and Turbidity from Water
Authors: Prasad V. S. , Chaudhuri Malay
Published: May 2018

A downflow column test (5 cm bed depth and 5 min bed contact time), employing tap water spiked with Escherichia coli (ca. 50 CFU/mL) and with or without natural turbidity (50 NTU), was used to screen filtration/adsorption media, prepared from locally available materials (bituminous coal, lignite,manqanese ore and iron ore, both raw as well as pretreated/impregnated with alum,ferric hydroxide, lime or manganese dioxide), in terms of their capacity to remove bacteria and turbidity from water. Based on bacteria removal and turbidity data, ferric hydroxide impregnated lignite (Fe-1ignite) and alum pretreated or lime impregnated manganese ore (alum-Mn ore or lime-Mn ore) ranked top among the twenty media tested, showing 100% removal of Escherichia coli with effluent turbidity not exceeding 5 NTU. In terms of chemical characteristics that may affect the aesthetic quality of drinking water, both Fe-lignite and lime-Mn ore were acceptable; however, Fe-lignite showed the least change in the filtered water quality. Effects of pH (5 – 10), ionic strength (0.005–0.0125) and temperature (20 – 35°C) on Escherichia coli sorption by Fe-lignite were investigated in batch sorption tests. In column tests using canal water with 3 min contact time, Fe-lignite produced filtered water with 0–4 CFU/mL coliforms and turbidity not exceeding 5 NTU. Fe-lignite was found to be a potentially useful media for domestic water filters in rural areas of the developing countries.
Wastewater Treatment for Effluent Reuse: Lime-Induced Removal of Excreted Pathogens
Authors: Gambrill M. P. , Mara D. D. , Oragui J. I. , Silva S. A.
Published: May 2018

High quality effluents suitable for crop irrigation can be produced by lime and Clarifloc treatment of raw domestic wastewater: in laboratory jar-test experiments the average percentage removals were 99.999 for faecal coliforms, 99 – 99.9 for salmonellae, 99.9 – 100 for total parasites and 99 – 99.9 percent for rotavirus. The average removals of COD and suspended solids were 79 – 87 and 97 percent respectively. Clarifloc treatment was marginally better than that achieved by lime.
Inactivation of Health-Related Microorganisms in Water by Disinfection Processes
Authors: Sobsey Mark D.
Published: May 2018

The recent literature on disinfection of health-related microorganisms in water and wastewater is reviewed. There is now considerable evidence that traditional microbial indicators of water and wastewater quality, such as total and fecal coliform bacteria, are inadequate to predict the presence or disinfection responses of several important, newly recognized bacterial, viral and protozoan pathogens. This review emphasizes the response to disinfection of waterborne microbial pathogens and potential indicators of recent recognition and public health concern. These organisms include heterotrophic plate count (HPC) bacteria, frank and opportunistic bacterial pathogens, such as Campylobacter jejuni, Yersinia enterocolytica, non-tubercular mycobacteria, Legionella spp. and pseudomonads; coliphage indicators and enteric viral pathogens, such as hepatitis A virus, rotaviruses and Norwalk virus; and protozoan pathogens, such as Giardia lamblia, Cryptosporidium, and the free-living amoeba (e.g., Acanthamoeba spp. and Negleria spp.). The responses of these organisms to widely used, traditional disinfectants, such as free and combined chlorine, and to disinfectants of more recent interest, such as ozone, chlorine dioxide and ultraviolet light, are reviewed. This review also attempts to identify the variety of factors influencing disinfection efficiency, especially those that interfere with disinfection. It is apparent that traditional microbial indicators, such as total and fecal coliforms, are more sensitive to disinfection than such pathogens of recent concern as mycobacteria, enteric viruses and protozoan cysts. Therefore, efforts must be continued to find more reliable indicators of disinfection efficiency and microbial water quality and improved methods for water and wastewater disinfection.
Statistics of Microbial Disinfection
Authors: Haas Charles N. , Heller Barbara
Published: May 2018

Engineering adequate disinfection processes and assessing risks associated with various disinfection options requires knowledge of kinetics of microbial inactivation as a function of design variables (e.g., dose, contact time). Often such information is obtained in batch studies and extrapolated to design conditions. By Monte Carlo techniques, we have shown that the use of a direct maximum likelihood evaluation for two types of data normally encountered, counts (PFU or CFU) and dilution experiments (MPN), leads to estimates of microbial inactivation rate parameters having lower bias and variance than other data reduction normally employed. This paper reviews the methodology of this technique and provides the theory for the computation of confidence limits for parameter estimates, and discusses how the data may be checked for consistency (goodness of fit determination).
Comparative Resistance of Bacteriophages Active against Bacteroides fragilis to Inactivation by Chlorination or Ultraviolet Radiation
Authors: Bosch A. , Tartera C. , Gajardo R. , Diez J. M. , Jofre J.
Published: May 2018

In order to assess the potential usefullness of bacteriophages active against Bacteroides fragilis for the monitoring of viral disinfection in environmental samples, the sensitivity to chlorination and to UV irradiation of bacteriophage B40-8 was evaluated in comparison to that of poliovirus type 1 (LSc2ab), simian rotavirus SA11, coliphage f2, Escherichia coli and Streptococcus faecalis.

The inactivation of the different microorganisms by chlorine or UV treatment was monitored in tap water and sewage. The results indicated that viruses persisted significantly (p<0.05) longer than bacteria in the presence of both disinfectants. Phage B40-8 was the most resistant microorganism to chlorination (p<0.05) while coliphage f2 was the most resistant to UV irradiation. In the latter, phage B40-8 was nevertheless as resistant as poliovirus and rotavirus. As expected, all microorganisms were significantly (p<0.05) more resistant to both disinfection procedures in sewage than in tap water. These studies lead to the suggestion of the use of bacteriophage B40-8, instead of indicator bacteria, for the monitoring of viral disinfection in sewage-polluted water.
Generalised Model of the Effect of Different Control Measures in Reducing Health Risks from Waste Reuse†
Authors: Blumenthal U. J. , Strauss M. , Mara D. D. , Cairncross S.
Published: May 2018

Health risks from wastewater and excreta reuse are assessed using an epidemiological definition of attributable risk instead of the presence of a microbiological hazard. Measures for health protection need not rely on total pathogen removal by waste treatment processes but may include ways to prevent direct human exposure to the wastes. The range of possible options for health protection includes: waste treatment, crop restriction, localised application methods, control of human exposure, and combinations of the different methods. A generalised model is used to show the effectiveness of each option in reducing health risks to agricultural workers and consumers of the crops grown. Three different regimes are available for rendering waste reuse ‘safe' to both workers and consumers, and several regimes are capable of reducing but not eliminating health risks. Case studies are given of the application of the model to wastewater and excreta reuse in agriculture and aquaculture in 6 different countries. The model can be used to aid decisions by planners and engineers to ensure that health protection measures are targetted towards specific exposed groups in the population, within their local context.

† The full version of this article will appear in Water Science and Technology, 2l(6/7), 567-577 (1989).
The Relationship between Water-Related Disease and Water Quality with Particular Reference to Urban Water Supply in a Developing Country*
Authors: Lloyd B. J. , Wheeler D. C. , Pardon M.
Published: May 2018

The problems of urban water supply and water related disease in the Americas are examined in the context of population growth and geographical features. The debate concerning the transmission of potentially water-borne pathogens is discussed. The factors affecting the quality of water supply services in a large metropolitan area (Lima) are described and the epidemiological characteristics of water-related disease summarised and compared with data from Africa (Lesotho).

A water quality additive index is proposed in order to identify the level of risk for each metropolitan district. This incorporates the presence of faecal coliforms and the absence of chlorine residual. A water-related disease product index (DPI) is also proposed which incorporates the incidence of typhoid, hepatitis and diarrhoea. The indices were matched for all districts, where adequate data were available, and a strong correlation was noted. The water quality index was divided into categories (A,B,C) and it was observed that these were generally dependent upon the water supply service levels. It is concluded that disinfection control is grossly deficient in most developing countries but essential for the control of water-borne disease.

* The full version of this article will appear in Water Science and Technology, 21(6/7), 579-591 (1989).
Methanogenic Degradation of Phenol and Benzoate in Acclimated Sludges
Authors: Kobayashi T. , Hashinaga T. , Mikami E. , Suzuki T.
Published: May 2018

Anaerobic phenol and benzoate degrading consortia were cultivated by acclimation of methanogenic sludges to be capable of degrading completely to CO2 and CH4 1,000 mg/l of phenol within 5–7 days, and 3,000 mg/l of benzoate within 5–7 days, respectively. By using the acclimated sludges, the effect of gaseous atmospheres (H2:CO2/80:20 and N2:CO2/80:20) on the biodegradability and the degradation pathways of phenol and benzoate were examined. Although the anaerobic degradation of phenol was accelerated in the H2/CO2 atmosphere compared with the N2/CO2 atmosphere, benzoate was accumulated. Degradations of benzoate and butyrate were inhibited in the H2/CO2 atmosphere under stirred conditions, but not under static conditions. Through a series of biodegradation tests by using several intermediates in phenol degradation reported previously, the anaerobic degradation pathway of phenol in the N2/CO2 atmosphere was suggested to be phenol → benzoate → cyclohexane carboxylate (or 1-cyclohexene carboxylate) → fatty acids → CO2,CH4.
Cyanide Transformation in Anaerobic Phenol-Degrading Methanogenic Cultures
Authors: Fedorak Phillip M. , Hrudey Steve E.
Published: May 2018

Cyanide, which is inhibitory to methanogenesis, is a common toxic contaminant in a variety of industrial wastewaters. Among these are coal conversion and coking wastewaters which contain phenolics which are amenable to biodegradation by methanogenic consortia.

Semicontinuous anaerobic phenol-degrading cultures were exposed to a range of total cyanide concentrations from 5 to 30 mg/l (free cyanide from 0 to 18 mg/l) for a 140-day period. The higher cyanide concentrations gave longer lag periods before the onset of methane production. After methanogenesis became established, the rate of methane production in cyanide-fed cultures matched that of the cyanide-free controls. In batch cultures, free cyanide was substantially removed before the onset of methanogenesis.

Addition of 14CN− to a semicontinuous culture demonstrated that the majority of the label was transformed to a product that remained in the liguid phase. Although the product has not been identified, thin layer chromatography analysis has shown that it is not one of the following detoxification products reported for aerobic biological systems: thiocyanate, β-cyanoalanine, valine, alanine, aspartate or asparagine; nor is the product ferrocyanide or a cobalt complex.

These studies have shown that methanogenic consortia can detoxify cyanide while they continue to degrade phenol.
An Update on Wastewater Reclamation Research and Development in Los Angeles County
Authors: Carry Charles W. , Miele Robert P. , Horvath Robert W. , Nellor Margaret H.
Published: May 2018

The Sanitation Districts of Los Angeles County have actively conducted over 25 years of research associated with wastewater reclamation and reuse. Projects have included treatment process evaluations for removal of total dissolved solids, nitrogen, phosphate, heavy metals, organics, bacteria and viruses. Additional research has evaluated the health significance of using treated wastewater for replenishment of potable groundwater aquifers. Results of these various research projects are presented along with recommendations by the State of California Scientific Advisory Panel on Groundwater Recharge regarding research needs in the area of potable reuse.
Removal of Phenols from Water by a Photocatalytic Oxidation Process
Authors: Davis A. P. , Huang C. P.
Published: May 2018

Photocatalyst, CdS, upon irradiation by bandgap energy produces electrons and positive holes. The positive holes are strong oxidizing agents that can render organic compounds such as phenol oxidized. The rate of phenol oxidation depends upon factors such as pH, phenol concentration, photointensity, oxygen concentration and temperature. An increase in the degree of chlorination appears to render phenols more oxidizable. Among the chlorinated phenols studied, the ease in oxidation increases in the order: 2,4,6-trichlorophenol > 2,4-dichlorophenol > 2-chlorophenol > phenol.
Treatment of Toxic or Refractory Wastewaters with Hydrogen Peroxide
Authors: Bowers A. R. , Gaddipati P. , Eckenfelder W. W. , Monsen R. M.
Published: May 2018

The partial oxidation of a variety of “non-biocorapatible” organics using hydrogen peroxide was evaluated as a pretreatment step prior to biological oxidation of these organics. The compounds tested were 2,4-dichlorophenol, dinitro-ortho-cresol and two unknown phenolic waste-waters of industrial origin. Fenton's Reagent, FeSO4, was used as the catalyst for production of reactive free-radical species at pH 3.5. The residual by-products of hydrogen peroxide oxidation were evaluated based on toxicity (MicrotoxR), and biodegradability (fed-batch reactors) in relation to a typical municipal sludge and a “standard” acclimated laboratory sludge. In all cases, the by-products were about an order of magnitude less toxic than the initial compounds. For example, given 650 mg/l of 2,4 dichlorophenol, the initial EC50 was 0.32% and the uptake rate (based on total organic carbon) by municipal sludge was 0.0 versus an EC50 of 2.5% and an uptake rate of 3.47 mg TOC/g VSS-hr after reaction with hydrogen peroxide.
Intensive Primary Flocculation-Sedimentation of Urban Wastewater
Authors: Grasmick A. , Elmaleh S. , Coma J.
Published: May 2018

The objective of this work was to intensify liquid-solids separation in the primary treatment of urban wastewater. Basically, the process consists of fluidizing a sand bed using grit-removed urban wastewater; the mechanical energy transferred to the suspension enhances the formation of clusters which grow in a maturation zone above the fluidized bed. The unit is also provided with an inclined multitubular settler in which a sludge blanket contributes significantly to pollution removal. The total efficiency is such that the process can compare with classical primary sedimentation, i.e., 60% reduction of total solids, but the required mean residence time is only 10 minutes instead of 120 minutes in a classical device. The total volume required is therefore a tenth of that normally required. The waste sludge also compares with a classical primary sludge, but it has much better settleability.
Biokinetic Parameters of a Photosynthetic Waste Stabilization Process
Authors: Carberry J. B. , Henshaw F. F.
Published: May 2018

Biokinetic parameters, characteristic of an innovative/alternative wastewater treatment process, were determined in order to demonstrate economical wastewater stabilization and the simultaneous generation of useful biomass. The Algal Bacterial Clay Treatment (ABCT) reactor was designed to be coupled with a mollusc filter feeder clarifier. Michaelis-Menten and Monod models were characterized experimentally for the ABCT reactor under varying conditions of mixing rate, aeration rate, light intensity, temperature, presence or absence of clay particles, and initial substrate concentrations under batch conditions in order to simulate a plug flow reactor. A final two-week continuous flow “steady state,” complete mix experiment was also conducted. Under the latter condition, data acquired for pH, CO2, and O2 diurnal fluctuations, using a data acquisition system and PC attached to the biostat reactor, documented the periodic CO2 limitation and O2 limitation. The lack of severe effects due to the diurnal limitations indicated that the ABCT strategy is efficient and potentially productive of useful biomass.
Combined Artificial Wetland and High Rate Algal Pond for Wastewater Treatment and Protein Production
Authors: Wood A. , Scheepers J. , Hills M.
Published: May 2018

The potential to optimize wastewater utilization, whilst achieving satisfactory nutrient removal has been investigated through a simple system combining an Artificial Wetland with a High Rate Algal Pond (HRAP). Receiving septic sewage at a surface loading equivalent to 13.5 cm/day the Wetland achieved COD removals of 59.2%, NH4−N of 34,6%, PO4−P of 31.9% and SS of 78%. The HRAP selectively cultivated an easily harvestable filamentous green alga through a combination of short hydraulic residence times (< days), and microscreens as selectors over the effluent stream. Passage of the effluent through this stage permitted COD removal to increase to 79.4%, NH4−N to 82.8% and PO4−P to 54.1%, whilst generating a highly proteinaceous (42% by wt) biomass at a rate of approximately 50 tons/hectare/year. This paper discusses the performance of the pilot scale facility over a twelve month period, identifying biological and operational influences on the system, and the physiological mechanics by which the wastewater treatment is accomplished.
A Computerized Degree of Hazard Assessment for Evaluation of Wastes: An Innovative Aid to Management of Residuals
Authors: Plewa Michael J. , Minear Roger A. , Ades-McInerney Diane , Thomas David L. , Miller Gary D.
Published: May 2018

To determine if a degree of hazard analysis could be implemented, a statistically representative sample of the Resource Conservation Recovery Act (RCRA) Special Wastes and the non-RCRA Special Wastes manifested for disposal in 1984 in Illinois were analyzed. The term “Special Waste” includes all federally-regulated hazardous wastes as well as industrial process wastes and pollution control wastes as defined by the State of Illinois (non-RCRA wastes). A criticism of the present Illinois regulatory system is that all Special Wastes have similar requirements for applications that allow their transport and disposal. The current system does not address the different environmental and health risks posed by these waste streams. A degree of hazard evaluation of Illinois Special Waste streams was an appropriate method to determine the impact of these wastes upon the public health and environment.

To conduct a degree of hazard evaluation of Special Waste streams it is necessary to have quantitative data of high quality. The degree of hazard approach permits a distinction among Special Waste streams based on an estimate of hazard based on scientific evidence. For poorly defined mixtures a need for a set of toxicity assessment tests is clear. Such tests would need to be rapid and within reasonable economic costs. Such a hazard evaluation could be conducted in a consistently fair manner with a high degree of accuracy.

Although this study was not designed to determine how the degree of hazard analysis could be used in a regulatory sense, it does illustrate procedures that could be employed by regulators. The degree of hazard evaluation has the added benefit of being relatively rapid while reducing subjectivity in the decision-making process. Finally, the evaluation can be economically positive in that those industrial waste streams that demand more costly disposal techniques may be identified and separated from those waste streams that pose little hazard to human health and the environment.