bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on the Secondary Indicator for Drinking Water Guidelines - Lead Poisoning and Renal Function
Authors: Suketa Y. , Nakajima H. , Ueda M. , Sobukawa Y. , Suzuki C.
Published: May 2018

The following results were obtained in this experiment: 1) Non effective doses of lead (p.o.) on urinary sodium excretion and serum sodium level were deduced to be about 0.5 and 0.7 mg Pb/kg/day, respectively by either only single dose or more consecutive doses of lead acetate to young male rats. 2) Moreover, non effective doses of lead (p.o.) on renal Na+, K+-ATPase activity and plasma ANP (atrial natriuretic peptide) were 0.5 mg Pb/kg/day at 1, 2 and 4 weeks of consecutive lead administrations. 3) Urinary excretions of sodium, potassium and calcium in healthy rats (Whistar albino) were demonstrated to be on the decline with aging, whereas urinary magnesium excretion was not changed or was slightly increasing, 4) Urinary sodium excretions in young and old rats were greatly augmented by lead doses. 5) Urinary calcium excretion in old rats was more incremented than in young rats. 6) Urinary excretion of the above electrolytes in female rats showed some different patterns from male rats by lead administrations.
Changes in the Concentration of Heavy Metals in the Zala Minor Balaton-Zala System (Water, Sediment, Aquatic Life)
Authors: Salánki J. , Licskó I. , László F. , V.-Balogh K. , Varanka I. , Mastala Z.
Published: May 2018

The changes in the concentration of seven heavy metals (Hg, Cd, Pb, Cr, Ni, Cu, Zn) in the water, sediment and aquatic organisms were studied in the River Zala, the largest tributary to Lake Balaton, and in the retention pond (Balaton Minor) created on the tributary. The samples have been collected at four stations, in ice-free periods, at monthly intervals for four years. In the water the mean concentrations of the heavy metals studies are one order of magnitude below the levels mentioned as allowable limits in the WHO recommendations on drinking water. In the sediment the concentration measured for the heavy metals remain below the limit acceptable for plants in soils (except for lead in the samples retrieved from the mouth of the River Zala). The concentration of solid lead and chromium compounds has surpassed in all samples that of the dissolved ones. The concentration of lead and chromium, but also that of nickel and zinc decrease thus perceptibly from the upper reaches of the River Zala towards the outflow from Minor Balaton. The analyses on fish and snails demonstrated the retention of Cu and occasionally of Pb and Hg in the pond, but also that the metal pollution reaching the pond is subject to seasonal and yearly fluctuations.
Alternative Methodologies for Predicting Metal Transfer in Marine Food Webs including Filter-Feeders
Authors: Amiard-Triquet C. , Martoja R. , Marcaillou C.
Published: May 2018

A methodology was developed in order to evaluate the role of suspended matter as a vector of metals in food chains. An experimental model was tested for Ag and Cu accumulation in oysters. After short-term exposures (Ag : 2 weeks; Cu : 3 weeks), metal levels in the soft tissues of oysters showed a preponderance of the direct uptake from water over metal transfer through microalgae or sedimentary particles. However, oysters retained a significant percentage of metals from paniculate sources and these vectors could get significant in chronic exposures. The major difficulty to overcome in order to generalize this methodology of contamination is to determine the alimentary demands of filter-feeders since responses to a kind of particles may vary considerably from species to species. Another approach consists of determining metal speciation in the most representative organisms at each trophic level in an ecosystem. The limiting factor of metal absorption is often the diet not in terms of the total mineral but the presence of more or less bioavailable metallic compounds as hypothesized for Ag2S in oysters. The predictive value of this alternative method needs tobe evaluated by determining directly the metal transfer in an experimental food chain including a small mammal.
Studies on Methods for Long-Term Monitoring of Environmental Pollutants in a Remote Region - Lake Mashu, Japan
Authors: Kawai T. , Shiraishi H. , Nojiri Y. , Tanaka A. , Furuta N. , Horiuchi S. , Ambe Y. , Soma M. , Otsuki A.
Published: May 2018

Following the recommendations of SCOPE in 1978, a ten year study of the methodology for background level monitoring has been conducted using a lake remote from human activities as a sampling “vessel”. The whole study has consisted of: 1. Selection of suitable lakes, 2. Selection of indicator pollutants, 3. Methods for ultra-trace analysis, 4. Examination of the representativeness of lake water samples, 5. Reading the history of pollution contained in the sediments, and 6. Elucidation of changes in loading sources of pollutants. The last subject is not yet completed. This paper focuses mainly on results for subjects 4 and 5. The characteristics of the remote Lake Mashu are discussed from the viewpoint of the effective background monitoring systems with high reliability. The representativeness of the water samples is assured by the hydrological characteristics of the lake and the homogeneity of lake water (caused by mixing). The mechanisms and critical conditions for thorough mixing are estimated. Records of pollution contained in the bottom sediments have been analyzed in conjunction with age data for the sediment layers. Sufficient fundamental information has been accumulated with the results of this study to propose an effective monitoring program for Lake Mashu to be continued for more than 100 years. It was concluded that an international network for monitoring of lakes is advisable.
New Methods for the Identification of Surfactants and Their Acidic Metabolites in Raw and Drinking Water: FAB-MS and MS/MS
Authors: Ventura F. , Caixach J. , Romero J. , Espadaler I. , Rivera J.
Published: May 2018

The suitability of fast atom bombardment (FAB) for the characterization of all class of industrial surfactants and their identification in raw and drinking water extracts is demonstrated. The behaviour of anionic, nonionic, cationic, phosphates and amphoteric surfactants under FAB conditions is shown and can be predicted. Some examples of accurate mass measurement as well as the usefulness of tandem mass spectrometry (MS/MS) for the characterization of unidentified or difficult peak assignation from FAB spectra of real samples are presented. The univocal identification of acidic metabolites of surfactants is also examplarized.
Cytotoxicity and Mutagenicity of Micropollutants in Drinking Water
Authors: Utsumi H. , Hakoda M. , Kiyoshige K. , Manabe H. , Mitade C. , Murayama J. , Han S.-K. , Hamada A.
Published: May 2018

In order to examine whether cytotoxicity test is available as bioassay of water micropollutants, cytotoxicities of 40 chemicals, which have been reported to occur in drinking water, were investigated using 3 different types of cultured cells including HL-60 cells, mouse peritoneal macrophages and rat liver hepatocytes, and the results were compared with their mutagenicity and carcinogenicity. Cancer promotion activity was assayed by use of morphological change of HL-60 cells. Lethality of chemicals was measured with trypan-blue exclusion test of HL-60 cells or lactose dehydrogenase released from rat hepatocytes. Influence of chemicals on cell functions was examined with phagocytic activity of macrophages and glycogenolytic activity of hepatocytes. Some of the chemicals showed strong cytotoxicities which depended on the structure of chemicals and the nature of cells, while cancer promotion activity was not found in any sample. Among the 3 tests, viability test using HL-60 cells was the most susceptible to the chemicals. No correlation was observed between the results of cytotoxicities and their mutagenicity. The results indicate that the combination of some cytotoxicity tests should become effective both to estimate the safety of drinking water and to identify the hazardous micropollutants.
Effect of Preozonation on Mutagenic Activity Generated by Chlorination of Humic Acid Dissolved in Water
Authors: Aso S. , Hayashi J. , Kusakabe K. , Morooka S. , Sera N. , Horikawa K. , Tokiwa H.
Published: May 2018

Aqueous solution containing ahumic acid was treated by ozonation, which was followed by chlorination with HCIO. The TOC level in preozonated samples was varied by changing ozone dosage. When 50% of the TOC was removed, the THMFP and TOX were destructed to ca. 1/30 and 1/20 of the respective initial values. The effect of preozonation on the mutagenic activity of nonvolatile organic chlorides generated by the chlorination was evaluated by the Ames test after the solute was separated on the basis of affinity for hydrophobic XAD-2 adsorbent and fractionation with various solvents. The overall mutagenic activity, defined as the number of revertants per unit volume of the solution considered, was expressed by the product of the following factors: concentration of nonvolatile matter in solution, mass fraction of hydrophobic component in the nonvolatiles, and number of revertants per mg of dosed hydrophobic component. The contribution of each factor was evaluated experimentally. Preozonation was effective for the selective destruction of precursors of the hydrophobic component.
Development of a Kinetic Model for Prediction of Priority Pollutant Removal from an Industrial Treatment Plant
Authors: O'Brien G. J.
Published: May 2018

Federal guidelines have been issued which regulate the aqueous discharge concentrations of priority pollutants for the organic chemicals, plastics, and synthetic fibers (OCPSF) Industries. Insufficient data existed in the literature to allow estimations of the removal of priority pollutants by a wastewater treatment plant (WWTP). The removals of eighteen organic xenobiotics were measured in parallel, aerated, continuous, mixed reactors. The influent to the pilot plants was primary effluent from an industrial 30 million gal./day wastewater treatment facility. The kinetic coefficients which characterize removal by biodegradation, powdered activated carbon (PAC) adsorption and air-stripping were obtained, and the values were used to estimate WWTP performance. Agreement between the steady-state model predictions and the WWTP data was surprisingly good for most of the compounds in spite of unsteady-state operation and the six millionfold scaleup. For compounds where severe transients occurred, the steady state model was unsatisfactory. The model was used to design a second stage “PACT” unit and to determine source control requirements. The model also can be used to estimate the relative importance of the three removal mechanisms in order to adjust WWTP operating conditions to enhance the removal of specific compounds.
The Feasibility Studies and Design of a Public Sewage Collection, Treatment and Outfall Scheme for the South Coast of Barbados
Authors: Herbert J. C. , Fries M. K. , Archer A. B.
Published: May 2018

In 1988, as part of commitment to maintain and improve the quality of beaches and nearshore waters along Barbados' densely populated south and west coasts, the Government of Barbados commissioned Reid Crowther International to carry out feasibility studies and the detailed engineering design of a public sewage collection, treatment and outfall scheme for the south coast. The studies and designs were completed in 1990 and the Government is now negotiating with the Inter-American Development Bank for funding to pay for the construction of the project.

The paper describes project background, estimation of design flows and loads, and treatment plant/outfall design including the detailed marine studies undertaken for the project. Interesting aspects of the sewage collection system design, including the proposed use of “No-Dig” trenchless sewer technology and the project's environmental impact assessment are also described.
Water Quality Improvements for Estuaries and Coastal Waters, North Devon, England
Authors: Willis R. P. , Martin J. C. , Ridout K. J.
Published: May 2018

Environmental protection legislation and public expectation require increasingly higher quality standards for coastal recreational waters. The immediate objective is compliance with EC Directives and UK legislation but consideration has also to be given to the possibility of higher future standards. The paper describes the environmental and engineering investigations for a major improvement scheme in an area of high amenity value where tourism is a principal source of employment. Schemes must be based on comprehensive survey data and a thorough evaluation to satisfy the requirements of the National Rivers Authority which is the regulatory body for discharges to the aquatic environment. A wide range of improvement options has been considered and the reasons for selecting the preferred options are explained. The significance of disinfection techniques and marine treatment are discussed. Over recent years a considerable interest has developed in environmental issues and consultation with customers, elected representatives and organisations has been important throughout the development of this scheme.
Effluent Disposal in a Pristine Environment
Authors: Barnhart E. L.
Published: May 2018

Recreational facilities and seasonal residences create unusual wastewater treatment problems. In the barrier islands of South Carolina the problem is further complicated by very restrictive water quality discharge regulations. On Fripp Island an activated sludge system has been employed to produce an effluent suitable for land disposal on the golf course. Use of the water in this way is economically attractive and minimizes the costs associated with golf course maintenance. The process can be modified to provide substantial nitrogen for the golf course turf requirements. On Hunting Island a total oxidation system which operates poorly is being replaced with a combined trickling filter and aeration system which should allow maximum flexibility in dealing with highly variable effluent loadings. The effluents from this system will be discharged through a constructive wetland avoiding any surface water discharge. The combination of these facilities results in a highly environmentally satisfactory discharge program. Sludge from the biological treatment operations on both Fripp Island and Hunting Island can be combined to produce sod for use on the golf course. Composting offers an alternative method of sludge disposal which is also environmentally satisfactory.
Biological Aerated Filters: An Adapted Biological Process for Wastewater from Coastal Areas
Authors: Pujol R. , Canler J. P. , Vachon A. , Vidou P.
Published: May 2018

SUMMARY

compact facilities together with modular and environment-friendly appearance are arguments in favour of Biological Aerated Filters(B. A. F. ) in coastal areas where the amount of available land imposes strict limitations on technological choices.

The operation of B. A. F. in combination with a physico-chemical process was studied using the data obtained from two wastewater treatment plants located in coastal areas (Barcares and Saint Palais/Mer, France).

The main conclusions are the following.-Effluent quality in terms of COD, BOD5 S.S. proved satisfactory for organic load conditions higher than those applied when using conventional procedures.-Adaptation to organic load variations is not a basic problem for this type of coastal community,but hydraulic flow-rate control should be the main concern.-Restarting plant operation after a long shutdown only takes a few days.-Furthermore technical and economical optimisation required continuous monitoring, especially in the field of washing and aerating control. This type of management involves the use of reliable, high- performance control equipment.
Anaerobic-Aerobic Wastewater Treatment System Suitable for Variable Population in Coastal Areas: The Ananox® Process
Authors: Garuti G. , Dohanyos M. , Tilche A.
Published: May 2018

Results of a four year experience on a combined anaerobic-anoxic-oxic municipal wastewater treatment process - named ANANOX® - are presented.

This process demonstrated to be highly efficient, with 89.6% CODt, 89.2% TSS and 81.2% N removal, and a sludge production of only 0.2 kg TSS.kg COD removed−1, a value which is roughly 50% less if compared with traditional nitrification/denitrification processes.

Energy needs are reduced with respect to aerobic plants, because the anaerobic COD degradation plays a major role, particularly during the warm season.

Sulphates play a very significant role in the process because, after being reduced in the anaerobic step, where they give a contribution to the organic matter degradation, they are reoxidized in the anoxic step by nitrates, reducing the organic matter need for denitrification.

Due to the high dependence of efficiency on temperature, the system proposed has advantageous uses for sewage treatment particularly in warm climates and in tourist and recreational areas where the population increases during the warm season.
Water Quality in Swimming Areas and the Influence of the Environment: A Tool for the Developer
Authors: Aurousseau J. M. , Amezal A. , Calba F.
Published: May 2018

The water quality in swimming areas is monitored by the DDASS by means of analyses carried out on bacterial contamination. These analyses have been made for the last 20 years; the results, however, have rarely been the object of statistical studies beach by beach.

In addition, from 1988 to 1991, the Agence de l'Eau Seine-Normandie carried out a statistical study on 10 beaches situated in the department of Seine-Maritime: Fécamp, Criel, Mesnilval, Le Tréport, Yport, Veulettes, Quiberville, St-Aubin, Dieppe-Place, Dieppe-Puys.

The statistical study measures the relationship between the level of contamination observed and environmental parameters such as pluviometry, the cycles and coefficients of the tide, coastal currents, and local topography.

The statistical tool used, analysis in multiple components, allows us to find the origin of pollutants, to better understand the mechanism which transports them to beach areas, and enables us to make decisions about future development.
The Situation and the Problems of Hazardous Waste Treatment in Germany
Authors: Shin I. K. C.
Published: May 2018

Yearly 4 900 000 tons of hazardous waste are generated in West Germany. The Germany Waste Disposal Act regulates not only the import and the export, but also the transit of wastes. Also avoidance of waste generation and recycling of wastes are emphasized by the act. To reduce waste amounts the collected wastes are treated preliminarily by chemical, physical and biological methods. 740 000 tons of hazardous waste are combusted annually in 27 incineration plants. 18 additional incineration plants are planned. Disposal of diluted acids in the North Sea was completely stopped by the end of 1989. Chlorinated hydrocarbons were burned on a German incineration ship. This was stopped in 1989. The most usual disposal process is the sanitary landfill. Rainfall results in water and soil pollution caused by leachates. A roof above the landfill could eliminate the generation of leachates. The safest disposal is the deep underground deposition in salt domes.
Trends in Innovative Treatment Technologies at Contaminated Sites
Authors: Kovalick W. W.
Published: May 2018

Increasing the diversity of technologies used to remediate contaminated soils and groundwater is one of the goals of EPA's Office of Solid Waste and Emergency Response (OSWER). While conventional methods of waste remediation, such as stabilization, containment, and incineration, are certainly valid approaches to resolving waste problems, statutory and economic considerations are now, more than ever, encouraging the entire remediation community to consider change in thinking and practice.
Kinetics of the Heterogeneous Ozonation of Nitrated Phenols
Authors: Gould J. P. , Ulirsch G. V.
Published: May 2018

The kinetics of the heterogeneous ozonation of phenol and 27 nitrophenols representing a wide array of functional groups have been studied. In the systems examined, the process has been found to be zero order with respect to phenolic concentration which indicates mass transfer as the prime control on the process. Analysis of the first order rate constants has permitted computation of overall mass transfer coefficients for all compounds. The coefficients were sixty percent lower than the kLa values measured by others in water and showed very little variation regardless of chemical structure of the phenol. Efforts at development of a QSAR model for the kinetics were fruitless.
Natural and Artificial Mercury Decontamination - Ottawa River and Minamata Bay (Yatsushiro Sea)
Authors: Kudo A.
Published: May 2018

Everyday, man creates new processes and materials whose properties are not fully known and are sometimes toxic to him and the environment. One of the worst cases was in Minamata Bay, Japan where a fatal accident occurred due to mercury pollution. The accident was unique in many aspects thus forcing the establishment of a new decontamination process for polluted areas. Two mercury polluted sites, the Ottawa River, Canada and Minamata Bay (Yatsushiro Sea), Japan, have been investigated to establish a fundamental approach for decontamination with special emphasis on natural and artificial processes and their problems. Artificial decontamination on bottom sediments has primarily cleaned-up Minamata Bay and the near-by Yatsushiro Sea considerably, an acceleration of the natural processes by 31.5 years. The surrounding area will be fully cleaned-up by natural forces, following the artificial work, by 2011 AD (or 20 years from now). This means that the natural decontamination has a half-life of 9.5 years in Yatsushiro Sea. For the Ottawa River, only natural processes were applied to clean-up the river system. It took 5 years for physical components to be decontaminated (a half-life of 1.20 years) while it took a longer period for biological components. This last finding was also true for Minamata Bay. This delay may be due to the longer life span of the biota and their efficient processes of bioaccumulation from diluted surrounding water. Based on the findings herein, a combination of both artificial and natural decontamination methods is recommended in consideration with the given environmental conditions.
Nocardioforms, Not Nocardia Foams
Authors: Soddell J. , Knight G. , Strachan W. , Seviour R.
Published: May 2018

Micromanipulation of branching actinomycete filaments from activated sludge foams resulted in the isolation of pure cultures identified as belonging to the genera Nocardia, Rhodococcus and Mycobacterium. The adequacy of microscopic examination alone in determining the organism(s) responsible for foam formation is questioned.
Short and Long-Term Responses to Changes in Hydraulic Loading in a Fixed Denitrifying Biofilm
Authors: de Mendonca M. M. , Silverstein J. , Cook N. E.
Published: May 2018

The long- and short-term effects of hydraulic loading were investigated in a pilot packed tower bioreactor used for denitrifying a groundwater used for drinking water. Field experiments were conducted at hydraulic loading rates of 3.63 and 7.24 m3/hr/m2. The long-term (21 day average) performance of the denitrification reactor and the short-term response (48 hour) to regular air scour are reported here. In summary, an increase in hydraulic loading resulted in a long-term increase in the half-order denitrification rate constant, so that, on average, nitrate removal was maintained in the 5.2 m tower. At the lower hydraulic loading rate (3.63 m3/hr/m2) denitrification performance in the first 48 hours after air scour was maintained; however at twice the hydraulic loading, several days were required to restore the biofilm performance to long-term average levels.
Transformation of a Petroleum Mixture in Biofilms
Authors: Bouwer E. J. , Chen C. T. , Li Y.-H.
Published: May 2018

Petroleum hydrocarbons from a lagoon storing waste oil in New Jersey have contaminated underlying soil and groundwater. Biofilm column studies were performed to investigate biotransformation of the petroleum mixture under aerobic and anaerobic conditions. The waste oil at concentrations ranging between 10 and 100 mg/L was continuously applied to glass bead columns that resembled porous media. The majority of the alkylbenzenes and polynuclear aromatic compounds identified in the oil mixture were simultaneously biotransformed by aerobic biofilms within a 2-hour hydraulic residence time. In a methanogenic biofilm column with 2-day hydraulic residence time, the mixture of hydrocarbons was initially removed by sorption with complete breakthrough occurring after 300 days of operation. After 600 days, the methanogenic biofilm acclimated to several of the specific hydrocarbon components, and effluent concentrations decreased due to apparent biotransformation. Radiotracer studies with toluene, naphthalene, and 2-methyl-naphthalene indicated partial mineralization to CO2 under both aerobic and methanogenic conditions. Reaction rates observed in the laboratory biofilms indicate that biotransformation could be an effective process to control hydrocarbon contamination in the environment.
Formation of Biofilms in a Biofilm Air-Lift Suspension Reactor
Authors: Heijnen J. J. , van Loosdrecht M. C. M. , Mulder A. , Tijhuis L.
Published: May 2018

Biofilm Air-lift Suspension reactors can be used to treat waste water at a high volumetric loading rate combined with a low sludge loading. The biofilms are formed on small suspended particles (r = 0.1 mm). We have studied the effect of particle characteristics and hydraulic retention time on the biofilm formation. It is shown that small, rough particles show the best biofilm formation. Low hydraulic retention times benefit the formation of biofilms. This results from the fact that suspension growth is minimal under these conditions.

The effect of biofilm detachment became distinct from the observation that most of the bacterial growth in the biofilm is transferred to the liquid. The biofilm formation process is concluded to be a three stage process: (i) the outgrowth of single cells to micro-colonies, this process is positively influenced by the carrier surface roughness; (ii) the outgrowth of micro-colonies to small biofilms, this process is negatively influenced by the concentration of carrier material; (iii) the outgrowth of biofilms, this occurs when the majority of particles are covered with a biofilm. At that time the influence of shear due to particle-particle interactions diminishes.
The Effect of Residual COD on the Biological Treatability of Textile Wastewaters
Authors: Orhon D. , Artan N. , Büyükmurat S. , Görgün E.
Published: May 2018

Textile effluents often contain an array of chemicals with different biodegradation characteristics. Consequently, it is quite difficult to evaluate and interpret the degree of COD removal that can be attained by biological treatment without identifying COD portions that are resistant to biodegradation. This study evaluates the biological treatability of textile wastewaters generated by the knit and wowen fabric finishing category with specific emphasis on the assessment of different residual COD components. A new method is proposed to experimentally measure the initial particulate inert COD. The method is tested to yield a value of 73 mgl-1 for this COD component, corresponding to 16 % of the particulate COD in the textile sample. A previously developed procedure is used to quantify the initial soluble inert COD and the residual COD generated through microbial metabolism during the treatment process. The ratio of the inert fraction to the soluble COD of the textile effluents is found to vary between 0.076 and 0.22. A similar ratio in the range of 0.04 - 0.09 is calculated for the residual microbial products. The kinetic and stoichiometric constants associated with the biodegradable COD are also experimentally measured. The residual components, together with the kinetic information about biodegradable fractions, are used to simulate the performance of activated sludge systems by means of a relationship between the total effluent COD and the sludge age. The results indicate that the residual components practically dominate the effluent COD and seriously challenge related effluent standards.
Analysis of Substrates for Methanogenesis in Anaerobic Sludges Using Specific Inhibitors
Authors: In S. J. , Fukui M. , Suwa Y. , Yamagishi T. , Urushigawa Y. , Mori T.
Published: May 2018

We examined what kind and how much of the specific inhibitor is effective for the estimation availabilities of substrates for methanogens in anaerobic sludges. The chloroform (0.1%, v/v) inhibited 90% of the methanogenesis in an anaerobic sludge (LD), which was cultivated with glucose, and was more effective than 2-bromoethanesulfonic acid (BES, 0-200 mM). Hydrogen, acetate and propionate were linearly accumulated when the methanogenesis was inhibited by 0.1% of chloroform. The propionate accumulation rate in the presence of chloroform was identical with that in the presence of high partial pressure of hydrogen (H2:CO2 = 20:80) which inhibits syntrophic H2- producing fatty-acids-oxidizing bacteria. This shows that the methanogens utilized hydrogen and acetate converted by syntrophic hydrogen-producing propionate-oxidizing bacteria through interspecies hydrogen transfer. Using chloroform (0.1%) as the specific inhibitor, in the LD sludge 49% of methane was estimated to be derived from propionate. The H2 + CO2 and acetate from the other pathway (NS), contributed 2 and 34% of the methanogenesis, respectively. This method was also applied to a municipal sewage digester sludge (MD). In the MD sludge, methanogenesis from propionate, H2 + CO2 and acetate via the NS pathway were 16, 2 and 78%, respectively. Major substrates for methanogenesis, therefore, could be estimated in anaerobic sludges.
Anaerobic Treatment of Sewage Sludge Treated by Catalytic Wet Oxidation Process in Upflow Anaerobic Sludge Blanket Reactors
Authors: Song J. J. , Takeda N. , Hiraoka M.
Published: May 2018

To increase the efficiency of methane recovery in anaerobic treatment, sewage sludge was treated by catalytic wet oxidation process(CWOP).The CWOP is designed to treat sewage sludge with the aid of a newly developed catalyst. It is a treatment process, by which concentrated COD components and suspended solids in various kinds of sludge can be simultaneously oxidized and treated with great efficiency in a single step without dilution. After CWOP, this supernatant was treated by upflow anaerobic sludge blanket(UASB) for recovery of methane. This experiment was to evaluate the acclimation of UASB process to the supernatant of sewage sludge treated by CWOP. For the granule growth and accumulation, supernatant was introduced stepwise (25%, 33%, 50%, 100%). The supernatant was 7,200 mg-COD/L which contained 53% carbonic acids. The reactor was operated at a volumetric loading rate from 1.8 (kg·COD/m3·day) to 14.4 (kg·COD/m3·day) and overall HRT of less than 24 hrs throughout the experiment.

In the conventional anaerobic biochemical process of methane gas recovery was limited to 50% of COD recovery. As a result of this study, the COD recovery to about 93% was obtained by the coebination of CWOP and UASB process.

The following conditions were enough for pretreatment: temperature, 270°C; pressure, 86kg/m2; stoichiometric air ratio, 1.1; reaction time, 24 min.

These results indicate that the CWOP-UASB process may be attractive as an alternative sewage sludge treatment.
Advantages of Fluidization on Granule Size and Activity Development in Upflow Anaerobic Sludge Bed Reactors
Authors: Guiot S. R. , Arcand Y. , Chavarie C.
Published: May 2018

Wastewater treatment processes such as upflow anaerobic sludge bed (UASB)-like reactors are strongly dependent on the aggregation of biomass into macroscopic granules (1-3 mm) which settle well. The effect of the liquid upflow velocity (vUP) on the mean granule size and on the hydrogen, acetate, propionate and glucose specific activities was studied, at various specific loading rates, using sugar wastewater. Reactors operated at 0.9 m h-1 behaved as fixed beds while those run at 2.2,4.4 and 6.6 m h-1 were fluidized. The vUP had a significant effect on granule mean geometric diameter (Dm) and on the specific activities. The Dm increased with the vUP, as a direct function of the hydrodynamic regime, rather than as a result of a specific wash-out of smaller particles at higher vUP. Acidogenic (glucotrophic) activity decreased when vUP augmented. All other post-glucotrophic activities (propionate, acetate, H2) were positively influenced by the vUP. The positive effect of vup increased with the specific loading rate (SLR). Glucose activity gradient within the granule bed was highly and inversely correlated to that of the granule size, while for propionate and acetate activity gradients, the correlation was direct, although less strong. No gradient was observed for H2 activity. These observations are discussed in details with regard to an ordered distribution of the consortium populations within the granule spatial structure. They support the so-called multilayer arrangement of anaerobic granules. These results are encouraging for environmental industries which are promoting UASB-like designs handling anaerobic natural granules under fluidization.
Nutrient Removal in a 2-Stage Biological Sewage Treatment Plant
Authors: Sickert E.
Published: May 2018

The Dradenau sewage treatment plant consists basically of a large activated sludge plant which supplements the treatment stages of the Köhlbrandhöft plant. Although built to mainly oxidize ammonia and despite unfavourable operating conditions - the different locations of the Köhlbrandhöft and Dradenau plants - considerable amounts of nitrogen have successfully been eliminated. Denitrification takes place in the distribution channel of the Dradenau plant and in one of the biological stages of the Köhlbrandhöft plant. This stage takes over the excess sludge from the Dradenau plant resulting in nitrifying - and denitrifying - part of the nitrogen load already here. There is an average overall reduction of 70 %. Simultaneous precipitation at the Köhlbrandhöft treatment plant reduces the phosphorus concentration in the effluent of the combined treatment plants Köhlbrandhöft/Dradenau to values recently set by legal regulations (1 mgP/l).
Filamentous Bulking in Massachusetts: Extent of the Problem and Case Studies
Authors: Switzenbaum M. S. , Plante T. R. , Woodworth B. K.
Published: May 2018

A handbook has been written for control of activated sludge bulking for wastewater treatment plant operators in Massachusetts. In order to demonstrate the principles described in the handbook for filamentous organism identification and subsequent selective control, six Massachusetts activated sludge plants experiencing bulking problems were investigated. In addition, a survey was conducted to determine the extent of the filamentous bulking problem in Massachusetts. Dominant filamentous organisms in the aeration tank mixed liquor were identified to determine the probable cause of bulking problems. Plant data and operating conditions were also studied to verify the organism-cause relationship. Based on the sample and data analysis, selective control strategies were suggested to the plant operator to control or eliminate the bulking problem.
Development of the Membrane Filter Press for the Processing of Sewage Sludge
Authors: Lowe P. , Shaw D.
Published: May 2018

The dewatering of sewage sludges using filter presses has been in common use for the past 80 years. The technology was mainly used in the UK for large waste water treatment plants especially where woollen grease was extracted from the sludge. It was also associated with the predrying of sludge prior to incineration in Multi Hearth Furnaces. To meet the growing demand for drier cakes and better capital productivity the membrane filter press has been developed. With the introduction of improved polyelectrolytes, polymer dosing systems, insitu cloth washing and computerised control the average pressing cycle has been reduced from 4-6 hours to under two hours. At the same time the dry solids content of the cake has become more consistent and for most waste waters in excess of 30%. The use of on-site pilot plant trails to determine the design criteria is now the accepted approach enabling sensible scale up and the setting of performance guarantees.
Extending the Wupper River Association's Large Treatment Plant at Buchenhofen for State-of-the-Art Technology
Authors: Brechtel H.
Published: May 2018

The Buchenhofen treatment plant operated by the Wupper River Association treats wastewater from 700 000 PE, roughly half of which is from industrial sources, using a conventional activated sludge process without specific nutrient elimination.

There is a management plan for the receiving waters of the treatment plant, the Lower Wupper. The main classes of use for these waters are specified in the plan. Use for recreational angling imposes the strictest limits for these waters, entailing a demand for water quality class II and imposing correspondingly stringent requirements on the purification capacity of the Buchenhofen treatment plant.

The Institut für Siedlungswasserbau, Wassergütewirtschaft und Abfalltechnik of the University of Stuttgart has been commissioned to evaluate realistic treatment objectives in the treatment plant and to prepare concepts for extending the plant to provide advanced treatment.

The most effective form of nitrogen elimination for the advanced concept has proved to be a single-stage activated sludge process with nitrification and pre-denitrification, while the most effective method of eliminating phosphorus is simultaneous precipitation followed by flocculation filtration. Tests have shown that large activated sludge tanks are not in themselves sufficient to ensure advanced nitrification without occasional peaks. Good on-line process monitoring and control are also necessary, as is buffering of inflow peaks.

A filtration stage will be added to the plant, coming on line in 1992. Advanced biological treatment based on results from a commercial-scale pilot plant should be completed by 1996. Total costs for extending the whole plant are estimated at more than DM 130 million.
The Fate of Heavy Metals in Wastewater Treatment Plants
Authors: Ghirardini A. V. , Avezzù F. , Cescon P.
Published: May 2018

In a previous paper the A.A. used a mathematical model to describe the complex mechanisms affecting heavy metals distribution between liquid and solid phases in order to predict the quality of effluents of an activated sludge biological treatment system. In the present work the mathematical model is employed to depict the behaviour of particulate and soluble zinc in large municipal wastewater treatment plants for which operating data were available in the existing literature. The results obtained by this model, compared with experimental data, describe zinc behaviour in activated sludge systems satisfactorily. The behaviour of some other metals (zinc, nickel, copper, chromium), studied in solid and liquid3 flows of a municipal wastewater treatment plant in the north-east of Italy (5000 m3/day), is satisfactorily simulated.
Upscaling a Compact Nitrogen Removal Process
Authors: Rogalla F. , Badard M. , Hansen F. , Dansholm P.
Published: May 2018

The new European Guideline on municipal wastewater discharges will require nitrogen removal in all sensitive areas below 15 mg TN/l. To achieve this limit within reasonable time and budget, infrastructure cost has to be minimised. To construct new sewage treatment plants close to urban neighborhoods or to upgrade existing facilites within current plant boundaries, high-rate reactors for nitrogen were investigated. The retained option was an upflow aerated filter on a floating granular media.

The lightweight media facilitates backwashing, and an anoxic zone at the filter bottom achieves denitrification. After extensive pilot tests to quantify the performance of the reactor, a demonstration plant of one full-scale filter cell was constructed and operated for two years to verify technological as well as process options. The dynamic behaviour of the reactor could be assessed by continuous reading of ammonia and carbon pollution. This paper describes the results obtained and the observed system limits.

The reactor was fed with primary settled wastewater containing about 450 mg COD/l and 65 mg TKN/l. Filtration velocity was varied between 1 and 2 m/h, and 100 to 300 % of the feed flow was recirculated. The removal rates at different temperatures were measured, under an applied load of 5 kg COD/m3 d, nitrification and denitrification capacities in the respective zones were around 1 kg N/m3 d at 15 °C. Up to 50 mg TN/l could be removed and the required effluent quality of the EC guideline could thus be achieved with an empty bed contact time of 2 hours. An additional on-site pilot test showed that within this same detention time, total nitrogen residuals down to 5 mg/l could be achieved at 10 °C.
Model and Sensor Based Optimization of Nitrogen Removal at Klagshamn Wastewater Treatment Plant
Authors: Aspegren H. , Andersson B. , Nyberg U. , Jansen J. la C.
Published: May 2018

Optimization of wastewater treatment plants with extensive phosphorus and nitrogen removal is complicated. The Klagshamn wastewater treatment plant in Sweden is operated with pre-precipitation of phosphorus with ferric chloride and denitrification with methanol as carbon source. An activated sludge process, operated with pre-precipitation and denitrification with external carbon source in a compartmentalized plant, requires only small tank volumes but increases the need for proper operation and optimization.

On-line nitrogen, ammonia, and TOC sensors are used for a day-to-day control and optimization while mathematical modelling is used for long term strategic planning. The on-line measurements are further used as the basis for the modelling. TOC and ammonia sensors at the influent clearly identify typical and extreme loading variations and nitrate measurements in the activated sludge tanks and the effluent shows the dynamics of the processes. These measurements provide a basis for model calibration. In combination low residuals of nitrogen, phosphorus and organic matter can be achieved.
Accounting for Different Time Scales in Activated Sludge Process Control
Authors: Kabouris J. C. , Georgakakos A. P.
Published: May 2018

A multirate approach is presented for the integration and discrete linearization of the activated sludge dynamics, that can be readily incorporated in optimal control and uncertainty propagation algorithms. This procedure fully accounts for the existence of multiple time-scale clusters in the activated sludge process and lends itself to a computationally efficient implementation. The method is verified in a computational case study involving a reduced-order version of the IAWPRC model.
Prospects for Transport Modeling of Process Tanks
Authors: Samstag R. W. , McCorquodale J. A. , Zhou S. P.
Published: May 2018

Mathematical modeling of process tanks has been dominated by one-dimensional and empirically derived “black box” techniques. This approach has until recently been justified by the intractability of the full equations of motion in these domains. Modern methods of computational fluid mechanics, however, offer the promise of obtaining underlying velocity fields with accuracy sufficient for the purposes of multidimensional transport models. This opens the prospect for calculation of spatial variations of particles, reactants, and products within a process tank. This would permit a realistic prediction of the influence of tank geometry on process performance. Basic approaches to transport modeling of process tanks are reviewed and applications to modeling of the activated sludge process are presented. It is proposed that multi-dimensional transport modeling, when coupled with full-scale and physical test work, can be used to conclusively determine geometric factors which determine tank performance.
Experience of Non-Potable Reuse of Wastewaters
Authors: Chin K. K. , Ong S. L.
Published: May 2018

Land area in the City State of Singapore is highly urbanized. Although 48% of the total land area of 620 square kilometres is reserved for water catchment and parks, water collected is insufficient to meet its needs. It derives its water mainly from Johor, Malaysia. To conserve water, reuse and recycling of wastewaters is encouraged in both the residential and industrial sectors. The Jurong Industrial Water Work was designed to reclaim treated sewage from the Ulu Pandan Sewage Treatment Plant. It has a capacity of 45,000 cubic metres per day. Pilot scheme to use this water for toilet flushing in housing estate was tried out. The scheme although highly successful is being suspended. The demand for reclaimed water from sewage for industrial water, however, increases steadily. This paper summarises the experience gained on reclaiming sewage for industrial uses.
Potential and Present Wastewater Reuse in Jordan
Authors: Gur A. , Al Salem S. S.
Published: May 2018

Reclaimed wastewater must be considered as an important component of the water budget in Jordan where water resources are rather limited. It has been estimated that wastewater effluents will amount to about 50% of the water deficit that is anticipated by the year 2000. This constitutes about 23% of the total renewable groundwater resource capacity. Quality characteristics of wastewater effluents from different treatment plants and other sources are presented. Review of institutional and legal aspects of water reuse is recommended toward encouraging treated effluent reuse. Outlines for a new reuse strategy have been suggested to ensure that wastewater reuse projects are operationally sustainable and environmentally sound.
Modeling Plant Uptake and Biodegradation of Semi-Volatile Hydrocarbon Compounds
Authors: Corapcioglu M. Y.
Published: May 2018

In recent years, the possible use of plants for treatment of the large volumes of slightly contaminated soils offered a potential alternative for waste management. This study develops a methodology to simulate the transport of semi-volatile dissolved hydrocarbon compounds in soil water and their interaction with plant roots. Microbial activity on the root surface is incorporated into the simulation by a biofilm model. Furthermore, the model takes root growth into account. The numerical solution of this study can be employed to assess the efficiency of an in situ remediation technique using plants, possibly cash crops like cotton, to clean an area contaminated by semi-volatile organics.
System Optimization of Stabilization Ponds
Authors: Meisheng N. , Kezhao Z. , Lianquan L.
Published: May 2018

In order to study the system optimization of stabilization ponds, this paper has set up its mathematical model. A series of optimization systems of stabilization ponds are recommended through optimum method under different flow rate, land price and total BOD removal rate. The three parameters are discussed, and the optimum method is improved.
Efficiency of Faecal Bacterial Removal in Waste Stabilisation Ponds in Kenya
Authors: Mills S. W. , Alabaster G. P. , Mara D. D. , Pearson H. W. , Thitai W. N.
Published: May 2018

Results for faecal coliform die-off rates are presented for seven different waste stabilisation pond systems in Kenya, which were sampled as part of a national pond monitoring and evaluation study carried out during 1988-1989. The results showed that average die-off rates through each pond series were considerably lower than those predicted from traditional design equations which are based on temperature (Marais 1974). Die-off rates were surprisingly higher in the primary ponds, which are designed for BOD removal, than in the maturation ponds which are designed for pathogen removal. Good correlations were found between faecal coliform first order removal rate constants and (a) temperature for the pond series as a whole, and (b) influent faecal coliform concentration for individual ponds.