bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of Biotechnology to Municipal Wastewater Treatment
Authors: Matsui T. , Kyosai S. , Takahashi M.
Published: May 2018

Application of biotechnology to wastewater treatment for its improvement and greater understanding was investigated in the Japanese national project named Biofocus WT as to a microorganism bank, genetic engineering application, immobilization of microorganisms, bioreactors for wastewater treatment, bioreactors for sludge treatment, SS separators for raw wastewater, biosensors and new wastewater treatment systems.
The Revival of Incineration in the UK
Authors: Lowe Paul , Groeger Georg
Published: May 2018

Incineration of sewage sludge was regarded In the UK In the 1970s as a viable method for the disposal of sludge. Towards the end of the 70s the operating costs, compared with those of other routes, were very high and all but 4 plants were closed down. In 1986 a contract was let to Lurgi (UK) by Yorkshire Water to construct the first new incinerator in almost a decade. The integrated design approach has resulted in competitive operating costs. This, together with environmental pressures to control or reduce other disposal routes such as recycling to agricultural land, landfill, and sea, has led to a renewed interest in the incineration process. As a result one further plant will be commissioned in January 1990 and other plants are now under active consideration.
Wastewater Treatment by a Submerged Contact Media Process Using Net Plates
Authors: Nambu T. , Kawarura K. , Kaneko M.
Published: May 2018

Wastewater treatment by using a series of bioreactors with submerged net plates, on which microbial growths could be developed, was studied to evaluate its treatment performance and to find suitable operational conditions for sufficient BOD and nitrogen removal. A comprehensive experimental study was carried out by using a bench-scale plant which treated artificial wastewater and a pilot-scale plant which treated municipal wastewater.

This process treated well the wastewater with higher pollutant loads in comparison with the conventional activated sludge process. The wastewater containing 200 mg BOD/l was reduced to 20 mg BOD/l at the high BOD loading of 1,94 kg/m3 day and the retention time less than 5 hours. Nitrogen removal could be explained well by an index defined as the product of the water temperature and the retention time. When the ratio, in flow rate, of recycled water to influent was 4 and the index was more than 400, nitrogen removal more than 80 % was obtained.
Reagentless-Continuous Flow Method for Determination of Aqueous Ozone with Thin Film Semiconductor and Application to an Advanced Water Treatment Plant
Authors: Aoki T. , Oguro H. , Fujiyoshi K. , Yamamoto M.
Published: May 2018

A method without any reagent for the determination of ultra-trace aqueous ozone, utilizing a glass tube-separation process and a thin film semiconductor, is proposed. The glass tube was used as the separator to transfer ozone from water into a gas phase. Ozone was transferred into clean air flowing in the tube and then was continuously monitored at the thin film semiconductor. Signals were proportional to concentration of aqueous ozone more than 5 µ g/L. The relative standard deviation (n = 7) las 3.8 % at 7.6 µ g/L. The interference from hydrogen peroxide, mono-chloramine, and dichloramine, was completely eliminated. The present method was applied to an advanced water treatment pilot-plant incorporating two parallel treatment trains and was examined for its potential for monitoring aqueous ozone in treatment processes.
The Role of Wastewater Reuse in Water Resources Management in Israel
Authors: Shelef G.
Published: May 2018

Wastewater reuse is considered as a major vital water resource in Israel with an annual flow of 420 million m planned for the year 2010 constituting 19% of the total water supply and about one third of the overall water allocated to the agricultural sector. The trend is for less crop restriction and wider crop rotation and thus higher effluent quality requirements. The economical considerations are favourable even with the need for seasonal storage and extra treatment. A brief description of the major wastewater reuse schemes, i.e. the Dan Region (Greater Tel-Aviv) and Greater Haifa - Tishlovet Hakishon is also given.
Use of Reclaimed Wastewater for Ornamental and Recreational Purposes
Authors: Ohgaki S. , Sato K.
Published: May 2018

Although Japan is not arid area, water for a clean environment in the heavily urbanized area is a scarce and precious resource. Several projects involving ornamental and recreational reuse using reclaimed wastewater have been practiced in Japan. The wastewater reuse only for ornamental purpose holds a unique position in water reuse techniques in the world. A guideline manual for ornamental and recreational reuse which has been examined by Ministry of Construction, Japan, is described with the water quality criteria for two categories of reuse mode, recreational reuse with close contact and ornamental reuse for scenery. The facilities, the management and operation techniques, and the benefit to the public of ornamental reuse system are illustrated and discussed by reference to a project (design flowrate 43,200 m3/d) for restoring live streams in Tokyo Metropolitan area.
Pilot Plant Studies on the Anaerobic Treatment of Different Wastewaters from a Fish-Canning Factory
Authors: Méndez R. , Omil F. , Soto M. , Lema J. M.
Published: May 2018

Most of the fish-canning factories are characterized by the variety of products to be processed and therefore by the production of effluents with different characteristics. When sea products are manufactured, generated wastewaters are very saline (10-20 gCl−/l) and have a high content of organic matter (10-50 g COD/l).

Based on previous studies of the characteristics of different streams generated at a representative factory, which cans tuna, mussel, octopus, sardine and also produces fish meal, and once lab-scale studies showed the viability of the anaerobic treatment, a pilot plant was built in the factory. It consists of a predigester of 7 m3, a suspended sludge digester of 15 m3 and a clarifier of 3 m3.

The main results can be summarized in these points: a) It is possible to obtain efficient anaerobic treatment of wastewaters with a concentration of chloride of 15 g/l. b) These wastewaters do not need the addition of nutrients, c) It is possible to treat individually or jointly all the streams generated in the factory. d) The particular results obtained with tuna- and mussel-canning effluents show that it is possible to reach 75-80% of COD removal when organic loading rates of 4 kg COD/m3.d were applied.
Industrial Wastewater Management in Developing Countries
Authors: Pareek N. K.
Published: May 2018

Most developing countries around the globe are striving hard for a fast economic growth and associated industrialization. As a result, numerous industries are emerging mostly in the urban areas of developing countries. The wastewater, which is an obvious byproduct of all industries, receives lower priority in developing countries. The plant designer and supplier normally provide an in-built pollution control system for new industries. The peripheral facilities, like wastewater treatment, suffer due to limited financial resources. In addition, other factors such as lack of experience in operation, management and plant repairs, lack of spare parts, frequent shortage of power/fuel, lack of end products disposal facilities, social and political reasons contribute to inadequate wastewater management in developing countries. Absence of industrial effluent standards and corresponding legislation for enforcing them are common in developing countries. Environmental impact assessment studies for the industrial growth are commonly not carried out in developing countries. Public awareness against pollution is also at a low profile in developing countries. The industrial wastewater problems in developing countries are discussed in this paper with some typical examples. The critical appraisal of the industrial wastewater management situation in developing countries is concluded by recommendations for the course of action.
Joint Treatment of Industrial and Municipal Wastewater – Case Project: City of Kotka, Finland
Authors: Väänänen Pentti , Pouttu Pekka , Kulmala Timo
Published: May 2018

The National Board of Waters in Finland has proposed a study on the joint treatment of industrial and municipal wastewaters of the City of Kotka. This study is of great interest due to the large forest products industry and food industry in Kotka. All of the wastewaters from the forest products and the food industry and the municipal sewage have been found to be suitable for biological treatment, which makes the joint treatment applicable. An activated sludge process is selected because it takes advantage of the large amount of nutrients in the municipal sewage and it has proved to be the most efficient treatment method for forest industry wastewaters.

However, municipal wastewater contains more nutrients than needed for the biological process, which can cause eutrophication problems in the watercourse. To reduce the pollution caused by the nutrients, chemical treatment of the wastewater is also proposed in the joint treatment. It was concluded that the joint treatment of wastewater is economically, technically and environmentally the best way to arrange wastewater treatment for the industry and the city.
Influence of Hydraulic Retention Time on Start-Up and Process Stability of Polyurethane Carrier Reactions
Authors: Rubindamayugi M. S. T. , Op Den Camp H. J. M. , Lubberding H. J. , Gijzen H. J. , Vogels G. D.
Published: May 2018

Influence of hydraulic retention time (HRT) on start-up of Polyurethane Carrier Reactors treating Volatile Fatty Acids (VFA) based wastewater, at constant organic loading rate (OLR) was investigated. OLR was increased stepwise after start-up to evaluate the influence of HRT on process stability. Four parallel experiements were conducted at HRTs of 48, 24, 18 and 12 hours. Results indicate an influence of HRT on duration of start-up period, and process stability after start-up. The reactor operating at HRT of 24 hours required only a relatively stort start-up period and showed higher process stability under steady-state condition. Analysis of individual VFA degradation indicated that butyrate and propionate consuming acetogenic bacteria increased in sigmoid fashion during start-up. Changes in acetate degradation do not show the true increase of acetoclastic population. Instead they reflect concomitant activity of VFA catabolizing acetogens and aceloclastic methanogens . Immobilized biomass increased exponentially during the first three weeks of start-up. The differences in start-up periods between reactors was probably due to differences in quality and activity of biomass immobilized at different HRTs. The HRT of 24 hours was most optimal to obtain stable reactor performance within a short startup period.
Use of the Immediate Maximum Specific Oxygen Uptake Rate as an Activated Sludge Process Control Parameter
Authors: Shamas J. Y. , Englande A. J.
Published: May 2018

The immediate maximum specific oxygen uptake rate (SOURim) was investigated as a potential process control parameter for the activated sludge system. Variability in effluent quality in terms of chemical oxygen demand correlated very well with the levels of SOURim at cell residence times of 3, 5, and 10 days. Transient response studied under batch growth conditions indicated a strong correlation between the SOURim, chemical oxygen demand, and the ribonucleic acid rates of change. The SOURim can therefore be used to qualitatively and quantitatively describe a given biomass thus making it a better suited parameter for use in process control strategies.
Lead and Cadmium Removal by Ion Exchange
Authors: Maliou E. , Malamis M. , Sakellarides P. O.
Published: May 2018

The ion exchange properties of the zeolites can be used to remove certain ions from the effluents.

In this work a natural clinoptilolite has been examined systematically in order to evaluate whether this low cost mineral can be employed for the removal of the metals lead and cadmium which are very toxic, even at very low concentrations.

Studies were performed under various conditions such as presence of different cations (Pb, Cd, Na), zeolite grain size, solution temperature. The results obtained indicate that the size of the zeolite does not affect the actual metal uptake at the equilibrium point, but the metal removal is greatly affected when the contact of the solid/liquid phases is short, a very essential parameter for the waste water treatment. For a short contact time the metal quantities removed using small grain size is nearly doubled. The same pattern is followed at higher temperatures, though a slight increase is observed for both zeolite grain sizes and both metals, lead and cadmium. At equilibrium half of the theoretical exchange capacity of the zeolite is used, approximately 1.4 meq/g for lead and 1.1 meq/g for cadmium.

The kinetic curves show very clearly the selectivity of the zeolite for the Pb ions but also significant amounts of cadmium are removed as well.
The Fate and Transport of Hazardous Chemicals in the Subsurface Environment
Authors: Ganji Doust Hossein , Huang Ju-Chang
Published: May 2018

Some volatile organic compounds (VOC's) such as 1,1,1-trichloroethane (TCA), trichloroethylene (TCE), and tetrachloroethylene (PCE) have been found as major groundwater pollutants which originate from the previous dump of these chemicals into unsealed ponds of landfill sites. One of the methods which has been proposed for cleaning these types of contaminants is to pump the groundwater out to the surface and then use air stripping to remove the VOC's. Knowledge of the fate and transport of these chemicals in the subsurface environment is necessary in predicting the time required for cleaning the groundwater. One of the major factors governing the transport and cleanup of VOC's in groundwater is the adsorption and desorption reactions of these compounds in the saturated and unsaturated soils. Thus, the objective of this study was to determine the rate and extent of adsorption and desorption of TCA, TCE. and PCE on clay and organic containing soils. The effects of solid concentration and sorbent characteristics were also investigated. It has been found that sorption and desorption are both very fast and reversible. The reactions fit well into the reversible pseudo first-order kinetic. The half time for the reversible adsorption is about 4 to 5 hrs, while that for desorption is around 15 hrs. The equilibrium adsorption follows the Henry's form of isotherm, or a simple partition model. The partition coefficients vary from .35 to 10 L/Kg at a test solid concentration of 40 g/L. When it is increased to 2700 g/L, the observed coefficients are reduced to only 5 to 50 percent. It has also been shown that for a sorbent having an organic fraction (foc) of 0.005 or greater, the partition coefficient, K, can be predicted from the following two models developed from this study:where Kow is the octanol-water partition coefficient and S is the solubility of VOC in mg/L.
Chemical Etiologies of Off-Flavor in Channel Catfish Aquaculture
Authors: Martin J. F. , Suffet I. H.
Published: May 2018

Thirteen ponds used for commercial culture of channel catfish were analyzed bimonthly during the summer and episodes of off-flavor occurred in nine of these ponds. Several compounds were isolated from the water and catfish that correlated with the onset and severity of off-flavor. The compounds most frequently isolated from water, producing off-flavored fish, were β-cyclocitral and 2-methylisobornepl (MIB). A dehydration product of MIB, 2-methyl-2-bornene, was found in several fish samples and two water samples. Geosmin and 2-methylenebornane were rarely isolated, β-cyclocitral was rarely isolated from the fish although high concentrations were isolated from water samples collected from ponds containing off-flavored fish. These compounds were not found in ponds producing on-flavored catfish.
Organochlorines as Environmental Tainting Substances: Taste Panel Study and Chemical Analyses of Incubated Mussels
Authors: Paasivirta J. , Rantalainen A.-L. , Welling L. , Herve S. , Heinonen P.
Published: May 2018

Lake mussels (Anodonta piscinalis) incubated in freshwater stations upstream and downstream of a large pulp mill were studied for tainting by a panel of 18 persons. The tasted animal muscle and tissue water samples, and composites of other simultaneously incubated mussels were analyzed for organochlorine compounds. Bad taste scores were obtained for mussels from the nearest station downstream to the pulp mill and were significantly (p < 0.001 **) higher than those from other stations. A similar difference was observed for the measured chlorophenol, chloroanisole and chloroveratrole, chlorocymene and PCB contents. Chloroanisoles and chloroveratroles were indicated to form the main tainting load in the studied mussels.
Volatile Organic Sulfur Compounds Associated with Blue-Green Algae from Inland Waters of Japan
Authors: Tsuchiya Y. , Watanabe M. F. , Watanabe M.
Published: May 2018

Volatile organic sulfur compounds produced by Microcystis isolated from inland waters of Japan were identified. Compounds with an unpleasant smell have been detected from seven strains of Microcystis aeruginosa and three strains of M.wesenbergii. Isopropyl mercaptan was detected in all strains and isopropyl disulfide from five strains. Methyl isothiocyanate, isopropyl methyl sulfide, and isopropyl methyl disulfide were also found in some strains. Isopropyl mercaptan and isopropyl disulfide were decomposed by chlorination, with the formation of isopropyl sulfonyl chloride. A mutagenicity study of isopropyl sulfonyl chloride and the chlorinated culture media produced by Microcystis was carried out using the Ames Salmonella/microsome assay.

Isopropyl sulfonyl chloride exhibited mutagenic activity for strain TA 98 in the presence of S9 mix and for strain TA 100 with and without the S9 mix. Some chlorinated algal cultures showed mutageic activity with strains TA 98 and TA 100, with and without the S9 mix.
Odorous Substances and Cyanobacterial Toxins in Prairie Drinking Water Sources
Authors: Kenefick S. L. , Hrudey S. E. , Prepas E. E. , Motkosky N. , Peterson H. G.
Published: May 2018

Algal blooms in eutrophic lakes have been regarded by some as primarily an aesthetic nuisance for recreational and drinking water uses despite well documented incidents of livestock and wildlife poisoning attributed to cyanobacterial toxins. A survey was conducted of three eutrophic, water supply lakes and eight rural dugouts experiencing cyanobacterial blooms. Biomass was characterized for dominant cyanobacterial genera and analyses were conducted for the hepatotoxins, microcystin LR and RR and the neurotoxin, anatoxin-a.

Some water samples collected simultaneously were screened for geosmin, 2-methylisoborneol and β-cyclocitral. Results showed that microcystin LR (LD50 of 50 µg/kg in mice) was present in concentrations up to 500 µg/g of algal biomass and microcystin LR levels were generally related to the proportion of Microcystis in the collected algal biomass. There was no relationship between the presence of microcystin LR and the presence of any of the odour compounds. Consequently, cyanobacterial odour-causing compounds in water did not provide reliable warning of the presence of the microcystin LR in these cyanobacterial blooms.
Methods for the Identification of Tainting Terpenoids and other Compounds from Algae
Authors: Veijanen A. , Kolehmainen E. , Kauppinen R. , Lahtiperä M. , Paasivirta J.
Published: May 2018

Off-flavour compounds produced by algae in freshwater ecosystems were studied for their structure using integrated sensory and spectroscopic methods: mass spectrometry (MS), nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR). Both solvent extraction and thermal desorption were used to isolate and to introduce the compounds into gas chromatography/mass spectrometry (GC/MS) and gas chromatography/Fourier transform infrared (GC/FTIR) systems. Ten ng of a terpenoid compound gave a readable IR spectrum. For 1H NMR studies the compounds were collected directly into NMR solvent by preparative gas chromatography. About 5 µg of a monoterpenoid compound was needed for a reliable 1H NMR spectrum. The mass spectral data indicated that the series of odorous substances detected by GC were terpenoid hydrocarbons and a later eluting series of compounds were sesquiterpene alcohols. In addition, one compound with an intense off-odour (aromatic, nitrogen containing compound) and some tainting carboxylic acids (derived from a starch factory) were detected.
Incidence of Off-Flavors in South African Surface Waters
Authors: Wnorowski A. U. , Scott W. E.
Published: May 2018

Incidents of odor in selected South African subtropical water bodies, the majority of which are sources of potable water, are presented. The presumed origin, prevalence and frequency of earthy/muddy off-flavors are described. Investigation into odor cases included the following: sensory and instrumental (gas chromatography/mass spectrometry) analyses of odorous water samples, enumeration and identification of cyanobacteria, algae and actinomycetes present in the samples and attempts to establish cultures of responsible microorganisms for confirmation of odor production. The possibility of concomitant production of toxins by odor-forming cyanobacteria is also discussed.

Incidence of off-flavors of 30% was established. All affected reservoirs were dominated by cyanobacteria, mainly Microcystis aeruginosa. Odorous substances detected in water were geosmin and dimethyl trisulphide. Efforts to isolate odor-producing organisms in culture were unsuccessful.

From individual case histories studied it is clear that odor incidents in man-made lakes present a serious problem in South Africa. The warmer climatic conditions and seasonally fluctuating water level create additional factors for odor formation, which are different from those experienced in more temperate regions.
Production and Reduction of Geosmin and 2-Methylisoborneol During Storage of River Water in Deep Reservoirs
Authors: van Breemen L. W. C. A. , Dits J. S. , Ketelaars H. A. M.
Published: May 2018

The Water Storage Corporation Brabantse Biesbosch manages three interconnected deep reservoirs in the south western part of The Netherlands. These reservoirs, with a total retention period of five to six months, are employed for storage and upgrading of polluted and eutrophic water from the River Meuse. In the first two reservoirs, with a total retention period of 4-5 months, probably due to adsorption/settling and biodegradation there is a reduction of geosmin and 2-methylisoborneol (2-MIB) down to 1-2 ng/l, i.e. 60-70% of the concentration in the river water. In the last reservoir Petrusplaat a large benthic cyanobacterial population consisting of various Oscillatoriaceae produces geosmin from February till June. In 1984 this production resulted in an average concentration of 6 ng/l, i.e. 5-6 times the concentration of the inlet of this reservoir. Since 1985 cyanobacterial growth is controlled by rooting up the bottom with a harrow. This resulted in average concentrations of 1-3 ng/l, i.e. twice the average concentration of the inlet. No further reduction of 2-MIB has been observed in this reservoir. It is concluded that storage of eutrophic river water in deep reservoirs reduces the concentration of geosmin and 2-MIB. Autochthonous production however may interfere with this water quality improvement.
Biodegradation of 2-Methylisoborneol by Oligotrophic Bacterium Isolated from a Eutrophied Lake
Authors: Ishida H. , Miyaji Y.
Published: May 2018

2-Methylisoborneol (MIB) is one of several causative compounds responsible for musty odor problems of drinking water. The purpose of this study was to investigate the kinetics of MIB biodegradation and utilization of other organics by Bacillus sp. This bacterium was isolated from the backwash water of a rapid sand filter used to treat water from Lake Kasumigaura. The isolated organism was an oligotrophic bacterium that can grow on a medium containing 0.1 mg/l of MIB as a sole carbon source. A laboratory experiment showed that a biofilm reactor seeded with the cells of this bacterium continuously removed approximately 90 % of 600 ng/l MIB.
Control of 2-Methylisoborneol and Geosmin by Ozone and Peroxone: A Pilot Study
Authors: Koch B. , Gramith J. T. , Dale M. S. , Ferguson D. W.
Published: May 2018

A pilot-scale study of ozone and PEROXONE (ozone in combination with hydrogen peroxide) for the removal of the odorous compounds 2-methylisoborneol (MIB) and geosmin in drinking water has been conducted at the Metropolitan Water District of Southern California. The study investigated the effects of ozone dosage, ratio of hydrogen peroxide to ozone (H202/03), and contact time. It was found that MIB and geosmin removal increased with higher applied ozone doses, but longer contact times over the range of 6-12 min were not significant. It was determined that 80-90 percent removal could be achieved with an ozone dose of approximately 4.0 mg/l, as compared to an ozone dose of approximately 2.0 mg/l at a H202/03 ratio of 0.2. Also investigated were the effects of alternative contactor configurations, ferrous sulfate as an alternative coagulant, bromide and ammonia addition, and simulated turbidity on the removal efficiencies of the two odorous compounds.
The Application of Effluent Characterization Procedures in Toxicity Identification Evaluations
Authors: Mirenda R. J. , Hall W. S.
Published: May 2018

A toxicity characterization protocol has been developed which incorporates many of the effluent fractionation techniques described in other procedural manuals and papers. The objective of this protocol is not only to determine the categorical source of toxicity, but also to provide an insight as to the appropriate treatment(s) which will result in toxicity reduction. This protocol has been applied to a variety of freshwater and saltwater municipal and industrial effluents. These applications have tested both fish and invertebrates and have been used to assess acute as well as chronic toxicity. The results of several studies are provided and discussed as to their success in identifying the toxic component(s) and/or providing a treatment option to alleviate the toxicity problem. A review of the limitations and precautions associated with these procedures and with data interpretation is also presented.
Research Agenda for Waste Minimization*
Authors: Peterst R. W. , Daniels E. J. , Wolsky A. M.
Published: May 2018

Because of the large quantities of materials and energy used by the chemical industry, significant opportunities are available for waste reduction. Waste reduction techniques include improvements in process selectivity and/or conversion, the ability to operate at lower temperatures and/or pressures, processes requiring fewer steps, feedstocks with fewer inherent byproducts, more efficient equipment design, products and/or catalysts with longer lives, more efficient unit operations, innovative process integration, avoidance of heat degradation of reaction products, new uses for otherwise valueless by-products, and elimination of leaks and fugitive emissions. The implementation of waste minimization alternatives in the chemical industry were categorized in terms of near- (0-5 years implementation), mid- (5-10 years), and long-term impacts (10+ years).

*The viewpoints expressed here are not necessarily those of the Laboratory or its sponsors.
Maximal Biodegradation Rates of Chloroform and Trichloroethylene in Anaerobic Treatment
Authors: Rhee E. , Speece R. E.
Published: May 2018

Computer controlled reactors were used to determine the maximal rate of anaerobic biodegradation of chloroform and trichloroethylene using three important anaerobic intermediates (propionate, hydrogen, and acetate) as primary substrates. Maximal biodegradation rate was defined as that loading rate of chloroform and trichloroethylene which can be achieved while reducing process efficiency of the primary substrate to 50 %. The systems were controlled by a computer in response to the pH of the reactor in order to establish the unlimited equilibrium utilization levels of the three primary substrates and the chlorinated aliphatic compounds. From 89 to 99 % of chloroform and trichloroethylene was biodegraded at maximal loading rate of 15-109 mg/l of reactor-day in the primary substrate enrichment cultures. Biodegradation potentials, the affected class of microorganisms, and the fate and metabolic intermediates of chloroform and trichloroethylene also were examined.
Enzyme Catalyzed Polymerization and Precipitation of Aromatic Compounds from Wastewater
Authors: Nicell J. A. , Bewtra J. K. , Taylor K. E. , Biswas N. , St.Pierre C.
Published: May 2018

Horseradish peroxidase enzyme (HRP) catalyzes the oxidation of aromatic compounds by hydrogen peroxide. Reaction products undergo a non-enzymatic polymerization to form water insoluble aggregates which readily separate from solution. The capabilities of HRP in catalyzing the precipitation of phenols from synthetic wastewaters in batch and mixed-flow reactors are being explored. Clearance tests have shown that HRP is effective in polymerizing phenolic substrates in water. The effects of varying aromatic, enzyme and peroxide concentrations are investigated. Aromatics and peroxide react with a one-to-one stoichiometry. The catalytic lifetime of HRP improves when the reaction is conducted at the optimum pH, below 35°C, and at low enzyme concentration. The choice of a reactor configuration for a continuous-flow process is based on the results of the batch and semi-batch reactor studies. Treatment of wastewater in a continuous stirred tank reactor improves catalyst efficiency.
A Study of Microbial Problems and Their Control in the Oilfield Waters
Authors: Vossoughi M. , Alemzadeh I.
Published: May 2018

Microorganisms present in injection water or other oilfield water may cause corrosion or plugging of lines and reservoir formation rock.

It should be pointed out that the mere presence of bacteria or other microorganisms in water does not necessarily mean that they present a problem.

Elimination or reduction of bacteria is justified only if it represents an economical solution to a corrosion or plugging problem.

This paper is an attempt to report the most important bacteria which grow in oilfield of Ahwaz (Iran), in order to control the action and their growth.

Sulfate reducing bacteria (SRB) were the most important and damaging bacteria in this area. They cause corrosion, and the iron sulfide produced as a product of the corrosion reaction is an excellent,plugging material.

The bacteria have been isolated from black deep sediments of a river in the neighbourhood of Ahwaz in which the sulfate concentration is high enough to promote the activity of SRB. The strains were first cultivated in anaerobic shakeflasks and progressively adapted to the culture contained carbohydrate and yeast extract as a model for primary experiment. The effect of the pH and temperature on the growth of bacteria under continuous cultivation show that the SRB grow under rather extreme conditions e.g. under pH ranging from 4 to 10, and temperature from 20 to 50°c.
Temperature Effects on Wastewater Characterization and the Release of Soluble Inert Organic Material
Authors: Sollfrank U. , Kappeler J. , Gujer W.
Published: May 2018

Whereas biokinetic parameters are known to depend on temperature, it is usually assumed that stoichiometry and wastewater composition do not depend on process temperature. With the aid of laboratory experiments with a Swiss wastewater of predominantly domestic origin it is demonstrated that the amount of inert, non-biodegradable organic material increases with decreasing process temperature. Based on changes in the composition of activated sludge, it is concluded that the inert material must originally be associated with a chemically reduced, slowly biodegradable, lipophilic fraction of the activated sludge, which contains little nitrogen.
Characterization of Functional Microorganism Groups and Substrate in Activated Sludge and Wastewater by AUR, NUR and OUR
Authors: Holm Kristensen G. , Elberg Jørgensen P. , Henze M.
Published: May 2018

Activated sludge functional microorganism groups: nitrifiers, denitrifiers and heterotrophs, were characterized through determinations of maximum specific utilization rates of ammonia (AUR) nitrate (NUR) and oxygen (OUR). Characterizations of the functional groups were done on activated sludges from a pilot plant and from full-scale plants. Influent wastewater covered a wide spectrum, including raw wastewater, primary wastewater and chemically pretreated wastewater. AUR determinations showed significant variation with influent COD:N ratio, and good agreement was found with expected rates from mathematical simulations. For increased contents of particles in influent wastewaters a decreased maximum OUR was found, while maximum NUR was slightly increased or not affected. Based on NUR and OUR the fraction of denitrifiers to heterotrophs was estimated in the range of 41-73% in nitrogen removal sludges. The results indicated that influent biomass is of significance for the obtained fraction of denitrifiers to heterotrophs. For a separate nitrification stage activated sludge without denitrification a fraction of denitrifiers of 15-20% was found. The results of endogenous NUR and OUR determinations indicated that hydrolysis of activated sludge COD takes place with the same rate under anoxic and aerobic process conditions.
Interpretation of Experimental Data with Regard to the Activated Sludge Model No.1 and Calibration of the Model for Municipal Wastewater Treatment Plants
Authors: Siegrist H. , Tschui M.
Published: May 2018

The wastewater of the municipal treatment plants Zürich-Werdhölzli (350000 population equivalents), Zürich-Glatt (110000), and Wattwil (20000) have been characterized with regard to the activated sludge model Nr.1 of the IAWPRC task group. Zürich-Glatt and Wattwil are partly nitrifying treatment plants and Zürich-Werdhölzli is fully nitrifying. The mixing characteristics of the aeration tanks at Werdhölzli and Glatt were determined with sodium bromide as a tracer. The experimental data were used to calibrate hydrolysis, heterotrophic growth and nitrification. Problems arising by calibrating hydrolysis of the paniculate material and by measuring oxygen consumption of heterotrophic and nitrifying microorganisms are discussed. For hydrolysis the experimental data indicate first-order kinetics. For nitrification a maximum growth rate of 0.40±0.07 d−1, corresponding to an observed growth rate of 0.26±0.04 d−1 was calculated at 10°C. The half velocity constant found for 12 and 20°C was 2 mg NH4-N/l. The calibrated model was verified with experimental dam of me Zürich-Werdhölzli treatment plant during ammonia shock load.
Sewage Treatment by UASB-Reactor. Operation Results and Recommendations for Design and Utilization
Authors: Vieira S. M. M. , Garcia A. D.
Published: May 2018

A 120 m3 UASB reactor for domestic wastewater treatment was designed and built, based upon results obtained through the operation of a 106 L pilot unit. This system was operated for four years for demonstration and technology development purposes. The results obtained in the first year of operation were already previously presented.

After this period, some modifications were carried out aiming at design and operation and maintenance and facilities improvement. This was followed by a continuous 2-year operating period. In this work are presented some of the results obtained in this second phase of operation, with hydraulic retention times ranging from 5 to 15 h, resulting in an effluent with 50 to 150 mg COD.L−1 and 40 to 85 mg BOD.L−1. Some criteria are presented, together with the experience acquired in the development of this technology from the pilot reactor phase. During this period, several lectures and discussions about the system were held in relation to its use, operation and efficiency, leading to considerations about the advantages and convenience of this choice, by establishing a comparison between it and other wastewater treatment processes.
Anaerobic Treatment of Domestic Sewage under Moderate Climatic (Dutch) Conditions Using Upflow Reactors at Increased Superficial Velocities
Authors: van der Last A. R. M. , Lettinga G.
Published: May 2018

This paper describes experiments with domestic sewage using a 120 litre expanded granular sludge bed (EGSB) reactor and a 205 litre fluidised bed (FB) reactor. Presettled domestic sewage was used in the experiments, because these reactor systems are inadeguate in removing SS. Compared to conventional UASB reactors, the advantage of EGSB systems is the significantly better contact between sludge and wastewater.

A batch recirculation system was used to assess the maximum achievable removal of the different COD fractions under EGSB and UASB conditions. The results obtained with the EGSB reactor reveal a removal efficiency of 90% with respect to the maximum obtainable efficiency of the soluble COD fraction under dry weather conditions. This efficiency can be obtained at hydraulic retention times (HRT) exceeding 3 hours. Even at HRT's ranging from 2 - 1.5 hours, still 84% - 77% of the maximum possible removal efficiency as assessed in batch recirculation experiments can be achieved at temperatures exceeding 13°C.

The advantage of EGSB systems is the high volumetric loading rate that can be applied while maintaining a high removal of the dissolved COD fraction. Moreover, little if any accumulation of inert suspended solids occurs in the sludge bed.

On the other hand, the poor removal of suspended solids can be considered as a disadvantage of these systems in treating domestic sewage.

Conventional FB systems using sand as carrier material were shown to have little prospect for treating settled domestic sewage, because hardly any methanogenic activity will develop in such a system.

However, it was also found that a very satisfactory guality granular sludge developed on settled sewage when operating FB systems in a mode similar to EGSB systems. This granular sludge appeared to be of a guality egual or even better than that of granular seed sludge, cultivated in a UASB reactor treating papermill wastewater.
Anaerobic Biodegradability of the Organic Components of Municipal Solid Wastes (OFMSW)
Authors: Peres C. S. , Sanchez C. R. , Matumoto C. , Schmidell W.
Published: May 2018

The aim of this research was to study the anaerobic conversion efficiency of the organic fraction of municipal solid waste (OFMSW). In order to compare and appraise our techniques and respective conversion efficiencies, primary sewage sludge (PSS) assays were also performed. OFMSW has a high cellulose content (32.9% TS) followed by lignin (12.5% TS), protein (9.61% TS), lipids (5.94% TS) and hemicellulose (5.2% TS). PSS is equally rich in lipids (19.8% TS), protein (18.2% TS) and lignin (19.6% TS), followed by cellulose (13.4% TS) and hemicellulose (5.5% TS).

Assays were run in CSTRbiodigesters operated at 35°C and 20 days hydraulic retention time (HRT). Three organic loading rates - 1.0, 2.7 and 3.8 OFMSW g VS/Lr.d (gram of volatile solids per liter of reactor per day) - were studied. PSS was assayed only at 1.0 g VS/Lr.d.

Concerning the conversion efficiencies, the most important component for the OFMSW anaerobic digestion is cellulose (74.0 - 77.8% conversion), while lipids (70.0 - 80.6% conversion) are the most important for PSS. The biodegradability of the other organic components are also presented and discussed.

Some literature data about OFMSW anaerobic digestion processes are discussed in view of the results presented here.

The similarities between our results and those of the so-called dry fermentation processes are also discussed in order to evaluate efficiencies of biogas and CH4 production versus volatile solids removal.
Dry Anaerobic Digestion of Solid Organic Waste in a Biocel Reactor at Pilot-Plant Scale
Authors: Ten Brummeler E. , Aarnink M. M. J. , Koster I. W.
Published: May 2018

Dry anaerobic digestion of the source separated organic fraction of Municipal Solid Waste (Vegetable, Fruit Yard waste) was studied in pilot-plant-scale reactors (5 m3, 450 m3). The maximum loading rate that could be applied was 7 kg VS/(m3.day) which is similar to the loading rate reported for experiments on laboratory scale. Per ton organic waste 70 m3 (STP) biogas could be recovered. A reactor temperature at start-up of 20 °C which was gradually increased to 35 resulted in a prolonged digestion time, while a temperature of 43 °C at start-up with a gradual decrease to 30 °C gave a similar digestion time as start-up at 35 °C. Particle size reduction of the Vegetable, Fruit and Yard waste resulted in a longer solids retention time which was related to the reduced leachate recycle flow that could be applied. The optimum value for the inoculum factor I, i.e. the ratio of inoculum solids and the initial total solids at start-up, was 0.5 - 0.6. A solids retention time of 30 days was observed. At higher values of I longer retention times were observed due to a suboptimal leachate recycle flow rate. At lower values of the inoculum factor (0.40 or lower) the solids retention time was 50 days or longer due to the relatively long period of suboptimal conditions (low pH, high organic acid concentrations).
Sequential Batch Anaerobic Composting of the Organic Fraction of Municipal Solid Waste
Authors: Chynoweth D. P. , Owens J. , O'Keefe D. , Earle J. F. K. , Bosch G. , Legrand R.
Published: May 2018

When kept free of toxic components, the biodegradable fraction of municipal solid waste (MSW) may be decomposed by aerobic or anaerobic composting and the residues either disposed of by land application or marketed as compost. Anaerobic composting is more economic because it effects similar conversion, does not require mixing or aeration, and produces the valuable energy product methane. This paper describes technical performance and systems analysis of a novel sequential batch anaerobic composting (SEBAC) process for treatment of high solids wastes that employs leachate management to provide organisms, moisture, and nutrients required for rapid conversion of MSW and removal of inhibitory fermentation products during start-up. The results of 19 trials with this system operated at 55°C and total residence times of 21 or 42 days exhibited about 50% conversion of organic matter with a methane yield of 0.2 m3 kg−1 volatile solids. The process was reliable and stable. A systems analysis showed that tipping fees employing this process were in the $30 per ton range and that economics were highly sensitive to biodegradability of feedstock and residue use options; they were relatively insensitive to process kinetics and leachate recycle rate. This process can be applied to in-vessel or controlled landfill designs.
Design and Performance of Pulsed Anaerobic Digesters
Authors: Stadlbauer E. A. , Achenbach R. , Döll D. , Jehle B. , Küfner B. , Oey L. , Quurck J.
Published: May 2018

The development of a Pulse-Driven Loop Reactor (PDLR), a Pulsed Anaerobic Filter (PAF) and a Pulsed Anaerobic Baffled Reactor (PABR) is described. In a PDLR internal circulation is achieved by a specially designed pulse-nozzle together with a concentric draft tube. In a PAF and PABR an oscillation is superimposed onto the biosuspension by means of a pulsator unit. Pulsed digesters enhance mass transfer processes. Consequently they facilitate degassing and prevent a build-up of acid spots in sludge beds. Laboratory- and pilot-scale evaluation using highly polluted distillery slops (pear, cherry, raspberry) as industrial wastewater show a COD removal efficiency of 70 -80 % at loading rates of 10 - 5 kg/m3*d. Contamination, both by sulfate (2 g/L) and copper (0.2 g/L), has a most adverse effect on anaerobic treatment of cherry-mashes, giving rise to a build-up of volatile fatty acids. Consequences for distillery plant operation are discussed.
Location and General Characteristics of Sediment Deposits into Man-Entry Combined Sewers
Authors: Bachoc A.
Published: May 2018

This study has the following principle aims.

– Identifying the contextual elements of sediment deposits which appear as the most important, or, in a way, as required conditions for clogging. It emerges that a weak slope is not a sufficient condition. We show that the main vulnerable sections are:downstream abrupt changes of geometry (the upper ramifications of man-entry sewers, the slope breakdowns, …)downstream flow losses (diffluence, overflows)under downstream influences (confluence, pumping stations, …). – Clearing the general characteristics of these sediment deposits in French man-entry combined sewers. The mean D50 varies from 1mm (Paris) to more than 2mm. The finest deposits are rather specifically located (upstream of local obstacles, or under downstream influences during dry weather - for instance near a pumping station, in very flat sewers -, or downstream from overflows). – Evaluating the representativeness of the results from more accurate studies carried out in particular places, for instance the Marseille No 13 trunk. – Drawing inferences about knowledge improvements and technical means.
The Göttingen Boat
Authors: Lorenzen A. , Willms M. , Dinkelacker A.
Published: May 2018

The Göttingen Boat is a new tool to measure sediment height and water depth in urban sewers without impeding their normal operation. The boat permits measurements in sewers of cross-section ranging from 0.70 m to 2.00 m and of 5 km of sewer per working day. The data acquisition is computer controlled. The results give information about where and how much sediment is in the sewer. Thus cleaning campaigns can be confined to these regions, which can help to save cleaning costs. The water height data give information about the structural condition of the sewer, in particular where the sewer sags.
The Erosion and Movement of Sediments and Associated Pollutants in Combined Sewers
Authors: Ashley R. M. , Wotherspoon D. J. J. , Coghlan B. P. , McGregor I.
Published: May 2018

The complex and inhomogeneous nature of sediments in sewers, and the variability of the particles and dissolved substances flowing in dry and wet weather combined sewage, make the prediction of sediment erosion and pollutant release a difficult proposition. It is apparent that the erosion of sediments in sewers can release pollutants in concentrations which exceed by many times the levels found in the various contributing sources of the sediments and pollutants, and whilst this release is normally in the form of an initial highly polluting foul flush at the start of wet weather flow, the occurrence of foul flushes has not been found to be ubiquitous, even from event to event in the same sewer. The origins of foul flushes may be attributable to the speedy erosion of a weak layer of highly concentrated surficial sediments (or bed-load) at the start of wet weather flows. Various models have been proposed, and some successfully applied to field data, to simulate the erosion and movement of sediments and associated pollutants in combined sewer systems.
The Use of a Water Quality Model for the Evaluation of the Impact of Marine Sewage Disposal on the Evoikos Gulf, Greece
Authors: Andreadakis A. D.
Published: May 2018

A eutrophication-dissolved oxygen water quality model was developed and applied in order to predict the environmental impact from the discharge of the sewage of some 700,000 inhabitants of Attiki, Greece to the nearby Evoikos Gulf. Three alternative treatment and disposal schemes were examined, including primary treatment, biological treatment and biological treatment combined with seasonal nitrogen removal. The critical water quality parameters were found to be chlorophyll-a and transparency and it was concluded, on the basis of the model results, that, unless a stable and sufficiently long thermal stratification of the water body is sustained, biological treatment with seasonal nitrogen removal should be adopted as the minimum degree of treatment prior to discharge.