bluuebunny/crossref_metadata_2025 huggingface dataset:
Anaerobic Treatment of Bleached TMP and CTMP Effluent in the Biopaq UASB System
Authors: Habets L. H. A. , de Vegt A. L.
Published: May 2018

The effluents from CTMP mills are on the one hand too dilute for evaporation and recovery, and on the other hand too highly polluted for conventional aerobic secondary treatment. In summer 1986 we therefore started an extensive research program in cooperation with the Ahlström Engineering division in Savonlinna, Finland, and Paques-Lavalin in Toronto, Canada, in order to investigate the anaerobic treatability of CTMP effluent, using UASB technology. This research included fundamental work in the lab, as well as on-site pilot work in Finland and in Canada.

As a result, two full-scale plants are in operation. The first plant was started up in October 1988 at Quesnel River Pulp in B.C., Canada, and is treating up to 140 tons of COD per day in two reactors of 3500 m3 each. The second plant was ready for start-up in January 1990 at the Enso-Gutzeit Kotka mill in Finland.

The cautious approach for these types of effluents was necessary due to earlier reports on the toxicity of softwood extractives, bleaching agent hydrogen peroxide, complexing agent DTPA and high sulphur levels. Besides this, it was necessary to confirm that granular seed sludge would not deteriorate but would develop normally.

The behaviour of hydrogen peroxide was especially interesting and the high redox potential caused could be resolved in a very cost-efficient way without utilising chemicals, enzymes or activated sludge.

Resin acids were indentified to be responsible for reducing methanogenic activity considerably. They were eliminated during aerobic post-treatment to very low levels. Lab studies clearly demonstrated how methanogenic activity could be increased by adding dilution water or aerobically treated effluent.

The concentration of the resin acids appeared to be associated with raw material (spruce, fir or pine), the season (summer or winter) and with fine fibrous material in the effluent. Sulphur levels in the effluent were relatively high, but resulting sulphide levels were not toxic to methanogens and COD/sulphur ratios were high enough to achieve acceptable removal efficiencies.

The paper presents the results from research as well as flow diagrams of the full-scale plants, and results from more than one year full-scale operation at Quesnel River Pulp in B.C. Canada.
Thermocatalytic and Chemical Treatment of Lignin-Aluminium Sludge and Utilization of the Resulting Adsorbent-Coagulant
Authors: Wolf I. V. , Chernoberezhsky Yu M. , Jepifantseva E. I. , Simonov A. D.
Published: May 2018

Lignin compounds pass through conventional biological treatment. Purification effiency can be improved by chemical coagulation with e.g. aluminium sulphate. The generated aluminium sludge can be converted into adsorbent-coagulant by thermocatalytic and sequential chemical disposal. A thermocatalytic reactor with the temperature range from 400° to 700 °C and with copper-chromium catalyst was applied to treat aluminium sludge. The resulting adsorbent-coagulant removed colour up to 95 % and COD up to 75 % from diluted kraft black liquor.
Nitrogen Dynamics of Pulp and Paper Sludge Amendment to Forest Soils
Authors: Henry C. L.
Published: May 2018

The use of pulp and paper sludge as a forest soil amendment was investigated in these studies. The fate of nitrogen added from field applications of P&P sludge was determined. Primary sludge was found to immobilize small amounts of N, while secondary sludge mineralized over 70% of the N over a 21 month period. A large portion (39-82%) of the mineralized N was not accounted for by uptake, soil storage and nitrate leaching, and was assumed to be gaseous losses. Growth response from P&P sludge amendments was measured. Surface application of primary sludge apparently had a beneficial mulching effect, as growth was 52-131% greater than in control soils. Addition of N to primary sludge resulted in growth 151-223% greater than in controls. Secondary sludge surface-applied resulted in excellent growth compared to controls (112-319% greater).
The Effect of Organic Compounds on Biological Phosphorus Removal
Authors: Abu-ghararah Z. H. , Randall C. W.
Published: May 2018

The effect of influent organic compounds on the performance of a biological nutrient removal system was investigated using a pilot plant system operated as a UCT (University of Cape Town) process. The system was fed domestic sewage and operated at a sludge age of 13 days. The effects of separate addition of formic, acetic, propionic, butyric, isobutyric, valeric, and isovaleric acid on phosphorus release under anaerobic conditions, and phosphorus uptake under aerobic conditions, were studied. The effects of the organic acid additions on the removal of nitrogen and COD, and changes in SOUR and MLSS, were also studied. All added substrates, except formic acid, caused significant increases in phosphorus release in the anaerobic stage, and subsequent phosphorus uptake in the aerobic stage with an increase in phosphorus removal efficiency. It was also found that the branched organic acids, isobutyric and isovaleric, caused more phosphorus release in the anaerobic stage and better phosphorus removal efficiencies in the system, compared with the nonbranching forms of the same organic acids. The most recent biochemical model, proposed by Comeau et al. (1986) and Wentzel et al. (1986) was also tested using the data collected in this investigation. Both models, in most cases, overestimated the ratios of phosphorus release to volatile fatty acid utilized. All added substrates caused no change in either COD or TKN removals. For engineering applications, it is suggested by this research, that at least 20 mg COD equivalent of acetic acid is needed for the removal of 1 mg phosphorus.
Practical Performance of Nitrogen Removal in Small-Scale Sewage Treatment Plants Operated in Intermittent Aeration Mode
Authors: Nakajima Jun , Kaneko Mitsumi
Published: May 2018

Research was carried out to clarify the number and the scale of small-scale sewage treatment plants operated in intermittent aeration mode by asking questions to maintenance workers in Chiba Prefecture, Japan. The percentage of the number of plants operated in intermittent aeration mode was 26.5%. This percentage was high in the plants larger than 200 population equivalent (p.e.). The practical performance of nitrogen removal was evaluated in nine existing plants operated in intermittent aeration mode. A high performance of nitrogen removal was noticed in the plants us ing extended aeration process. The performances of nitrogen removal in two plants operated in intermittent aeration mode were compared with those operated in continuous aeration mode. The characteristics of denitrification taking place in the aeration tank in a plant operated in intermittent mode were investigated by measuring the change in nitrogen concentration in the tank during the intermittent period. The seasonal performanee of denitrification was studied by a long term practical experiment for 16 months. By operating the length of intermittent time according to the change of the water temperature in the aeration tank, a high performance of nitrogen removal was obtained throughout the year.
Nutrient Removal in a Reed Bed System
Authors: Haberl R. , Perfler R.
Published: May 2018

Since 1984 investigations concerning sewage technology, plant physiology and soil properties have been carried out on the reed bed system at Mannersdorf/Leithagebirge (local loamy soil, Phragmites, planted area 3×150 m2, influent 30 - 50 mm/d). The removal efficiency of COD and BOD5 amounts to 80-90 % and 90 - 98 %, respectively. Elimination of nutrients (NTOT and PTOT) varies from 3 0 to 60 %, in general. Total nitrification cannot be reported for any of the plots fed with different sewage qualities. Nutrient uptake of NTOT and PTOT by Phragmites a. reaches 30 or 15 % of influent sewage load during July and August but is of no importance with respect to the average of the year. The proportion of PTOT in the soil is still increasing every year and now amounts to about 450 mg/100g soil. The concentration of phosphorus essentially stagnates at the level of 50 mg/100g soil.
Full-Scale Experiences with Phosphate Crystallization in a Crystalactor®
Authors: Eggers E. , Dirkzwager A. H. , van der Honing H.
Published: May 2018

The first full-scale phosphate removal plant is nearly one year in operation. Values of 0.5 mg/l P or less are possible. No extra surplus sludge is produced, but a relatively small amount of waterfree pellets, which can be reused in the phosphate processing industry.
The Selector Effect on Filamentous Bulking in Long Sludge Age Activated Sludge Systems
Authors: Gabb D. M. D. , Still D. A. , Ekama G. A. , Jenkins D. , Marais G. v. R.
Published: May 2018

A survey of long sludge age activated sludge plants in South Africa showed that bulking was widespread in nitrogen and nitrogen and phosphorus removal plants with the dominant causative filamentous organisms being the low F/M types 0092, 0675, 0041, Microthrix parvicella, 0914 and 1851. The literature suggests that in aerobic systems proliferation of the low F/M filaments can be controlled by aerobic selector reactors. From an extensive investigation into the selector reactors, and the effect these stimulate, it was concluded that in long sludge age systems, irrespective of whether or not a selector effect is present in the sludge, (1) under completely aerobic conditions low F/M filaments do not proliferate, (2) sequential or alternating anoxic-aerobic periods like intermittent aeration are necessary, though not sufficient, conditions for the proliferation of low F/M filaments, and (3) an aerobic selector installed on an intermittent aeration system did not control low F/M filament proliferation.
Filamentous Bulking and Hindrance of Phosphate Removal Due to Sulfate Reduction in Activated Sludge
Authors: Yamamoto Ryoko Ikemoto , Komori Tomoaki , Matsui Saburo
Published: May 2018

Sulfate reduction in the activated sludge cultivated with glucose and peptone in the sequential batch reactor system and the continuous anaerobic-oxic system was examined. In both systems, sulfate reduction occurred. When the sulfate reduction ratio increased, Type 021N or Beggiatoa sp. grew in the sludge and settling characteristics became poor. These results suggested that sulfate reduction was a cause of growth of the filamentous bacteria which could utilize sulfide for the energy source. There was a tendency that the greater the sulfate reduction ratio was, the smaller the phosphate removal ratio was. As a result of batch experiments using the mixed liquor and the wall growing sludge, it was demonstrated that the sulfate reducing bacteria grown in the activated sludge mainly produced acetate from propionate and lactate. About 107~108 MPN of sulfate reducing bacteria grew in 1 g of the activated sludge and about 109 MPN grew in 1 g of the wall growing sludge.
Control of the Growth of Filamentous Microorganisms Using Predacious Ciliated Protozoa
Authors: Inamori Y. , Kuniyasu Y. , Sudo R. , Koga M.
Published: May 2018

We have examined the optimum conditions for the growth of ciliated protozoa that feed on filamentous microorganisms, and the development of a method of mass culture and the fixation of this type of ciliated protozoa in activated sludge, in this paper. At first we determined that the ingestion method of filamentous microorganisms by ciliated protozoa differs according to the type but that they have in common a special small oral organ called a cytopharyngeal basket. Then we succeeded in separating and subculturing Trithigmostomacucullulus and Trochililioidesrecta as protozoa that feed upon filamentous microorganisms such as Type 021N, Sphaerotilusnatans causing the bulking from biological sewage treatment plants. By using these predacious protozoa it was clarified that SE medium (activated sludge extract solution) was most effective as a growth factor of T.cucullulus, one of the successfully separated protozoa, and that the optimum growth temperature of T.cucullulus in the presence of SE medium is about 20°C, and that stigmasterol, Vitamin B12 and thiamine are very effective in increasing the predacious protozoa as another growth factor. Furthermore it was made clear that the T.cucullulus and T.recta differed in the rate of ingesting filamentous microorganisms, and the rates ranged from about 1 to 30 microns per second. From these results it can be understood that bulking might be eliminated in a very short period of time, if these protozoa exist in large quantities and ingest filamentous microorganisms at about the same rates.
Activated Sludge Modelling and Simulation
Authors: Gujer Willi , Henze Mogens
Published: May 2018

The matrix format for the presentation of biokinetic models is explained with a simple model and expanded for the ‘Activated Sludge Model No. 1' of the IAWPRC Task Group for Mathematical Modelling for Design and Operation of Biological Wastewater treatment. With the aid of a simulation program a complex activated sludge model which includes two organic substrates and nitrification is developed stepwise and compared to experimental results.
Assessment of the Initial Inert Soluble COD in Industrial Wastewaters
Authors: Germirli F. , Orhon D. , Artan N.
Published: May 2018

The commonly used COD parameter does not differentiate between inert and biodegradable organic matter in wastewaters. This differentiation is quite necessary and significant for industrial effluents with high organic content. In such strong wastes the soluble influent COD fraction may severely interfere with the treatability results or challenge the effluent limitation criteria adopted for different industrial categories. The methods suggested in the literature to identify this fraction are not designed to differentiate between soluble inert organic matter and soluble residual microbial products generated during the experiments. This paper proposes two different methods for the assessment of the initial soluble inert COD fraction and summarizes their comparative evaluation. The methods are tested for five different industrial wastes characterizing pulp and paper, meat processing, antibiotics, textile and dairy effluents with total soluble COD concentrations ranging from 1000 to 9300 mgl−1. The results indicate significant interference of soluble residual microbial products which may be identified and corrected for with the proposed methods.
Time Series Analysis Models of Activated Sludge Plants
Authors: Novotny V. , Jones H. , Feng X. , Capodaglio A.
Published: May 2018

Time series models of the activated sludge process are very useful in design and real time operation of wastewater treatment systems which deal with variable influent flows and pollution loads. In contrast to common deterministic dynamic mathematical models which require knowledge of a large number of coefficients, the time series models can be developed from input and output monitoring data series. In order to avoid “black box” approaches, time series models can be made compatible and identical in principle, with their dynamic mass balance model equivalents. In fact, these two types of models may differ only in nomenclature. ARMA-Transfer Function models can be used for systems which are linear or can be linearized such as typical BOD or suspended solids influent-effluent relationships for which the type of model is known. For systems which are highly nonlinear, and/or the input-output model is unknown, neural network models can be used. Both ARMA-TF models and neural network models can be made self-learning, that is, the performance of the model can be periodically improved manually or in an automated mode as new information is collected by monitoring. Application examples are included.
Comparison of One-Phase and Two-Phase Anaerobic Digestion Processes in Characteristics of Substrate Degradation and Bacterial Population Levels
Authors: Cheng Zhang Tian , Noike Tatsuya
Published: May 2018

The comparison of one-phase and two-phase anaerobic digestion processes in the characteristics of substrate degradation and the bacterial population levels was investigated by using the chemostat-type reactors to which starch was fed as substrate when both processes were operated under the same experimental conditions. By decreasing the SRTs of both systems from 10.2 d to 5 d, 2.5 d and 1.75 d. it was found that the two-phase system was more stable to the change in pH than one-phase system. The CH4 recovery rates and COD removal rates in the two-phase system increased by 4 to 9% and 3 to 10%. respectively, although the CH4 recovery rate and the COD removal rate in the one-phase system were slightly higher than those in the two-phase system at the SRT of 10.2 d. The concentration of propionate in the effluent of the one-phase system was 30 to 50% higher than that in the two-phase system; while the concentrations of acetate and butyrate in the one-phase system were slightly lower than those in the two-phase one. The enumeration of the bacteria was performed by the MPN method. The population levels of acidogenic bacteria in both systems were in the same order (108 to 1010 MPN/ml). the population levels of hydrogenotrophs were also in the same order as the acidogenic bacteria in the two-phase system, while the population levels of hydrogenotrophs were 10 to 100 fold less than that of acidogenic bacteria in the one-phase system. The number of HAc-utilizing methanogens in the methanogenesis of the two-phase system were 2 to 10 times higher than that in the one-phase system. Therefore, the one-phase system cannot be regarded simply as the sum of acidogenesis and methanogenesis.
Removal of Organic Constituents in Municipal Sewage Using Anaerobic Fluidized Sludge Blanket and Anaerobic Filter
Authors: Tanaka S. , Ichikawa T. , Matsuo T.
Published: May 2018

The removal of various organic constituents in municipal sewage was investigated using anaerobic fluidized sludge blanket. (AFSB) and anaerobic filter (AF). Experimental results revealed that the AFSB reactor could treat the sewage more efficiently than the AF reactor and the removal efficiency of organic latter greatly varied in constituents. At hydraulic retention lines in the range of 8 to 24 hours, 50% COD reduction and 59% TOC reduction can be achieved by the AFSB reactor at 37°C. Lipids, proteins and carbohydrates can be highly removed, but the removal efficiency of surfactants is very low under anaerobic conditions. Methane production was rather limied (0.12 m3/kg COD removed at STP) and the COD reioval by sulfate reduction seems not to be neglected. The sludge production during 272 day operation times was 0.272 gVSS/g COD removed in the AFSB reactor.
Study of Biofilm and Fluidization of Bioparticles in a Three-Phase Liquid-Fluidized-Bed Reactor
Authors: Trinet F. , Heim R. , Amar D. , Chang H. T. , Rittmann B. E.
Published: May 2018

A three-phase, liquid-fluidized-bed biofilm reactor was operated over wide ranges of liquid velocity, air velocity, medium concentration, and substrate surface loading. The biofilm characteristics (total colonization, polysaccharide content, density, and thickness) and the specific detachment coefficient (bs) were determined by a combination of experimental measurements and a hydrodynamic model. The results demonstrated that dense and thin biofilms were induced by the physical condition of high particle-to-particle contacts and high liquid turbulence. The biofilm's polysaccharide content was increased by increased air turbulence and a low substrate availability. The specific detachment coefficient, bs, was strongly correlated to the concentration of the medium (negatively) and the polysaccharide content (positively). Overall, the bs can be controlled significantly by the gas and liquid velocities; increasing either velocity tends to increase bs.
Significance of Spatial Distribution of Microbial Species in Mixed Culture Biofilms
Authors: Fruhen M. , Christan E. , Gujer W. , Wanner O.
Published: May 2018

Experimental data from a biofilm reactor, in which two groups of organisms (Nitrifiers and Heterotrophs) compete for dissolved oxygen, were analyzed by a Mixed Culture Biofilm Model. The objective was to investigate to what extent and how fast relative abundance and spatial distribution of microbial species in a mixed culture biofilm changed upon variations of the bulk fluid substrate composition, and what the consequences of these changes were for substrate removal. Experimental results showed that within nine days the nitrification rate in a biofilm of constant thickness could change by a factor of five. Model predictions indicated that these changes must be due to a significant shift of the biofilm population. The distribution of the autotrophic and heterotrophic species over the depth of the biofilm turned out to be an important aspect of mixed culture biofilm behavior. Since it is difficult to observe the microbial population and its spatial distribution experimentally, the Mixed Culture Biofilm Model has proved to be a valuable tool for the interpretation of the observed phenomena.
Denitrification of Landfill Leachate by the Modified Rotating Biological Contactor (RBC)
Authors: Hosomi Masaaki , Yuhei Inamori , Matsushige Kazuo , Sudo Ryuichi
Published: May 2018

In order to remove high-strength nitrogen and organics in landfill leachate simultaneously, the modified RBC which was combined with the standard RBC and the anaerobic biofilter was proposed. The treatability for actual landfill leachate of the standard RBC and the modified RBC was evaluated. The capability of COD removal in the modified RBC is much greater than that in the standard RBC, although both RBCs showed a BOD removal rate of more than 95%. This suggested that the combination method of aerobic and anaerobic treatment was effective in reducing refractory organic compounds. The nitrogen removal in the modified RBC was about 90% compared to 50% in Che standard RBC. The modified RBC had the advantage of nitrogen removal because nitrification and denitrification proceeded efficiently, even if a carbon source was not added. The performance of the modified RBC was superior to that of the standard RBC in both BOD surface loading and BOD volumetric loading.
Application of Three Step-Biological Pond with the Use of Aquatic Plant for Post Treatment of Petroleum Wastewater in Vietnam
Authors: Triet L. M. , Viet N. T. , Thinh T. V. , Cuong H. D. , van Buuren J. C. L.
Published: May 2018

The effluent from activated sludge treatment of petroleum wastewater was treated with the aid of a ponding system using aquatic plants (Water Hyacinth, Chlorella, Reed). A good result was obtained in this study. Pilot pond system shows that the purification efficiency depends on the residence time of about 14 days. The petroleum removal waa 97-98 %, the COD removal was from 88-93 %. The dissolved oxygen amount (with Chlorella) increased from 0.7 mg/l to 9.8 mg/l and the pH increased from 6.9 to 8-8.6.

The application of 3 step biological pond with the use of Water Hyacinth, Chlorella, Reeds for post treatment of petroleum wastewater is appropriate in Vietnam.
Nutrient Removal from Aerated Lagoons Using Alum and Ferric Chloride – A Case Study
Authors: Narasiah K. S. , Morasse C. , Lemay J.
Published: May 2018

Laboratory and on-site studies were conducted for over one year on an existing aerated lagoon treatment plant treating domestic wastes, the main objective being the removal of phosphorus. Two coagulants, namely alum and ferric chloride, were used throughout the study. It was confirmed during the study that alum reacts preferentially with polyphosphates and not with orthophosphates in the precipitation process. Seasonal temperature variations do not appear to affect the coagulation and flocculation process adversely. The molar capacity of alum for precipitating the orthophosphate fraction is greater at secondary level of treatment compared with that at primary level. The phosphorus removal efficiency varied between 90 and 95 percent in case of both coagulants.
Japan's Aqua Renaissance '90 Project
Authors: Kimura Shoji
Published: May 2018

Aqua Renaissance' 90 is a six year R & D project for water reuse and energy recovery supported by the Japanese Ministry of International Trade and Industry. The objective is to develop low cost treatment processes utilizing bioreactors coupled with membrane separation units to produce reusable water from industrial waste water and sewage. Polymeric and ceramic membranes in capillary, hollow fiber, tubular and plate and frame modules have been tested in conjunction with bioreactors on a number of actual waste water and sewage streams. This paper will focus on membrane performance and power consumption. Recent results from test plant operation indicate that treatment of concentrated waste water by membrane separation units uses less than a third of the conventional power requirement.
Effects of Activated Sludge Properties on Water Flux of Ultrafiltration Membrane Used for Human Excrement Treatment
Authors: Sato Takeshi , Ishii Yasuhiko
Published: May 2018

We studied the relationship between water flux of a UF membrane with MLSS, soluble COD, and the viscosity of activated sludge suspension in a human excrement treatment test plant utilizing UF membrane.

The bench-scale plate and frame UF membrane test unit was operated for activated sludge suspension of 20~29 kg/m3 MLSS, 500-730 g/m3 soluble COD and 0.38-1.3 Pa·s viscosity under the conditions of 0.2-0.24 MPa average pressure and 2 m/s recirculating velocity. As a result, stable-state water flux was 0.55-1.65 m/D at 25°C.

The relationship between filtration resistance R to transmembrane pressure drop ∆P, MLSS, COD, and viscosity η was expressed by the following equation:

From this equation, we were able to predict R with an accuracy of ±24%. Soluble COD had the largest effect on water flux followed by MLSS. The effect of viscosity was relatively small.
Application of Fiber Adsorbents in Water Treatment
Authors: Suzuki Motoyuki
Published: May 2018

Fibrous adsorbents have an advantage of fast adsorption rate and easiness of handling when compared with granular adsorbents and powdered adsorbents. Application of newly commercialized activated carbon fiber in the field of water treatment and development of fiber supported zirconium oxide adsorbent for phosphate removal are introduced. For designing fiber adsorbent beds, axial dispersion in the bed becomes an important factor in determining a breakthrough behavior of the bed. Estimation method for axial dispersion coefficient in fiber beds is given on the basis of isotherm relations and bed properties.
Operation of Centralized Sludge Treatment Facilities
Authors: Kaneko Senji , Shimomura Hachiro
Published: May 2018

Construction of sewerage systems in the city of Yokohama has proceeded at a rapid pace ever since the first wastewater treatment plant went into operation in 1962. By 1984, all eleven of the planned wastewater treatment plants were in operation. By March 1989, the sewerage service rate had reached 80 percent, representing over 2.56 million of the city's residents.

Naturally, the expansion of the sewerage system was reflected in a commensurate increase in the quantity of sludge for treatment and disposal. Recognizing the critical importance of keeping abreast of this increase, the city has promoted the development of technology for more efficient treatment and disposal of sludge throughout the intervening years.

In recent years, the city has also seen extensive urbanization and mounting concern among its citizenry for conserving the environment. In response, it was decided to shift from the former decentralized method of sludge treatment (i.e., treatment of sludge at the plant generating it) to a method of centralized treatment at two sludge treatment centers, each built within a different wastewater treatment plant located in the waterfront area. Yokohama was the first city in Japan to adopt this form of centralized sludge treatment.

The construction of the centralized sludge treatment facilities made extensive use of results from a program of technological development. The centers feature the first egg-shaped digestion tanks, a high-concentration mode of digestion made possible by the use of centrifugal thickeners, power generator fueled with digestion gas, effective use of the waste heat from these generators, and the saving of fuel by the use of incinerators equipped with dryers.

The record for the first year of full-scale operation clearly demonstrated the merits of centralized treatment. The quantity of digestion gas generated at the center was double that of the quantity generated under the former method for an equivalent quantity of sludge. Power generation fueled by digestion gas supplied 64 percent of the center's own power needs. While operating at only one-fifth of the planned sludge capacity, the center boasted a savings of about 200 million yen for the year, and the treatment costs were less than half of the treatment cost of the same quantity utilizing the former method.

This report presents an account of the operational record for the first year of this center (the Hokubu Sludge Treatment Center) and the system of effective energy use that took place in it.
Introduction of Deep Oxic/Anoxic Tanks at Hendriksdal Sewage Treatment Plant to Increase the Capacity
Authors: Hultgren J. , Möllersten I. , Reinius L.-G.
Published: May 2018

The requirements for purification of sewage will be more stringent in Sweden in the future. For Henriksdal sewage treatment plant situated in rock, the proposed limit concentrations for BOD7, total phosphorus and total nitrogen are 10, 0.3 and 14 mg/l respectively as an average over the year. For nitrogen removal in the plant, the volumes of the biological stage have to be increased from about 70 000 m3 today to about 200 000 m3 in the future. There is space available in the rock for only a few new aeration and sedimentation tanks. To achieve adequate volumes, the aeration tanks must be deepened from 5 to 12 m. This paper provides a brief information about the ideas for extension, the investigations on pilot plant scale with operation of deep aeration tanks and the design of the future plant.
Dissolved Oxygen in Small Wastewater Collection Systems
Authors: Saldanha Matos J. , Ribeiro de Sousa E.
Published: May 2018

This paper concerns the dissolved oxygen (DO) balance in sewers and describes the experimental work and results obtained under a research project undertaken on a small wastewater collection system. For prediction of oxygen balance in sewers, reaeration and DO consumption, both within the stream and within the biological slime layer on the pipe wall, must be computed. In this study special emphasis is given to DO uptake by the slime layer.

Comparison of experimental results concerning the activity of the slime layer with the results calculated by the Pomeroy and Parkhurst equation, the only one available in the literature applicable to sewers, did not lead to a good agreement.

Under low flow conditions and high DO concentrations, a significative correlation was found between velocity and DO consumption by the slime layer. No correlation was found between DO concentration within the stream and DO utilization by the slime layer.
Feasibility Evaluation of a Novel Method for Destruction of Organics
Authors: Mikhail Khudenko Boris
Published: May 2018

Based on previous theoretical studies performed by the author, a possibility of the cementation induced oxidation-reduction of organics has been postulated. Experiments with pure aqueous solutions of selected refractory and hazardous organics and industrial wastewater have confirmed such a possibility and demonstrated very high process rates and efficiencies.
Ferrite Process; Heavy Metal Ions Treatment System
Authors: Tamaura Y. , Katsura T. , Rojarayanont S. , Yoshida T. , Abe H.
Published: May 2018

The principle of the “Ferrite Process”, heavy metal ions treatment system, and the practically operated systems are presented. In the “Ferrite Process”, the heavy metal ions are incorporated into the lattice points of the ferrites in the course of the formation of the spinel structure by the oxidation of the Fe(II) ions. The ferrite formation reaction proceeds in two paths depending on the reaction pH; 1) the green rust path (pH 7-10), and 2) the γ-FeO(OH) path (pH 10.5-11). The mole ratio of the heavy metal ions incorporated into the lattice points to the Fetotal in the ferrites depends on the reaction pH and the mol ratio of the heavy metal ions in the reaction solution and to the Fe(II) ions added to the reaction solution. Ferrite Process is now practically adopted to the treatment of the laboratory waste waters at the universities and the institutes in Japan, to the treatment of the plating waste waters, and to the treatment of branching mine drainage waters. Since the ferrite sludge has a strong magnetic property, it is reused as a useful magnetic material.
Prediction of Oxygen Transfer Rates from Simple Measurements of Bubble Characteristics
Authors: Pöpel H. J. , Wagner M.
Published: May 2018

The oxygen transfer rate (OTR) in tap water is generally determined by the instationary absorption method, a precise but rather time consuming and tedious method. Moreover, large quantities of sodium sulfite and water are used in practice when testing aeration equipment in larger tanks.

Therefore, a model is proposed by which the oxygen transfer rate can be calculated on the basis of simple and rapid measurements of the air bubble size and its distribution and of the total air content in the water applying a recently developed technique. The accuracy of this method is checked by the absorption method and can be rated as reasonable (0 to 13 % deviation). Greater accuracy is obtained at smaller bubbles (<3 mm) and improvements in this respect are proposed.

The proposed method of calculating the OTR from air bubble measurements is considered as a potential improvement of the usual absorption method. Due to its still lower accuracy it can be used at present only in conjunction with the latter method, reducing its chemical and water consumption.
International Perspective on Water Resources Management and Wastewater Reuse – Appropriate Technologies
Authors: Bartone Carl R.
Published: May 2018

The unabated urbanization and industrialization process in many arid and semi-arid countries leads to increasing demand for municipal and industrial water supply, often in direct competition with irrigation demand. In such cases wastewater reclamation and reuse should be an integral component of water resources management strategies. National reuse policies should be developed and implemented taking into account local conditions and based on affordable approaches that ensure safe reuse practice. This paper describes research and development carried out in several developing countries on appropriate technologies for implementing reuse, as well as coordinated international efforts to provide recommended guidelines and policies for safe wastewater reuse in agriculture and aquaculture.
Ground Water Recharge with Sewage Effluent
Authors: Bouwer Herman
Published: May 2018

Sewage effluent is an excellent source of water for irrigation, especially in dry areas. Before it can be used for unrestricted irrigation, conventional treatment should be followed by treatment so that the water meets the agronomic, public health, and aesthetic requirements for unrestricted irrigation. This usually means reduction of nitrogen concentration to less than 10 mg/l, complete removal of pathogenic organisms, and essentially complete removal of suspended solids and biodegradable organic carbon. This can often be achieved with a groundwater recharge system, using the soil and aquifer materials as natural filters. Studies on two experimental projects in Phoenix showed that “soil-aquifer treatment” systems can reduce nitrogen concentrations from about 20 mg/l to about 7 mg/l, fecal coliform concentrations from about 3500 per 100 ml (chlorinated secondary effluent) to 0.3 per 100 ml, viruses from 21 plaque-forming units/l to 0, suspended solids from 15 mg/l to 1 mg/l, and total organic carbon from 20 mg/l to 3 mg/l. The latter represents mostly the nondegradable carbon. Hydraulic loading rates for sands to loamy sands were about 300 ft/yr. Thus, 1 acre of infiltration basin can renovate about 300 af/year of sewage effluent. The renovated water should be removed from the aquifer to avoid its spread into high-quality native groundwater.(Please note that af/year stands for acre feet/year.)
Wastewater Reuse for Irrigation in the Near East Region
Authors: Arar A.
Published: May 2018

Limited water supplies available in many countries of the Near East has led to a growing interest in the rational use of this increasingly important resource. Because wastewater irrigation ensures the reuse of resources and achieves better treatment of wastewater, plans have recently been formulated for large-scale use of this non-conventional source of water. Consequently, in several countries of the Near East Region, wastewater reuse in agriculture is an accomplished and accepted fact, with a high degree of social and political commitment. Intensive and direct reuse is being practised in Kuwait, Saudi Arabia, Libya, the United Arab Emirates and Tunisia. Direct, but unsupervised reuse is iking practised in Yemen Arab Republic, Morocco and Syria. All forms of wastewater reuse is practised in Egypt. Indirect and direct restricted reuse is practised in Jordan. However, given the health and environmental hazards associated with reuse of wastewater, the formalization of wastewater treatment and reuse in all countries is urgent. Furthermore, in most countries poor coordination amongst the different agencies concerned with water supply, wastewater treatment, irrigation, public health and the environment is a key constraint for further wastewater reuse.
Public Attitude towards Water and Water Reuse
Authors: Ahmad Shamim
Published: May 2018

This study presents the results of a survey regarding public perception and attitude towards water and water reuse in Doha located in the arabian gulf. The water supply is very generous but is corrosive due to which it often acquires a red colour. Invariably home filters are used in the kitchen and washer to get rid of the colour and taste in water. People are aware of the high cost of water production and supply in such an arid region but they did not respond positively towards sharing the cost of improvement in the water supply in spite of the fact that they pay very little for receiving more than adequate water supply.

The community in general is not well informed about the water conservation measures and the water reuse. People seemed to be prejudiced against water reuse. A large percentage of respondents did not favour water reuse in lawns and gardens, car washing, toilet flushing, industries and farming.

There is a need for better channel of communication between the water departments and the community for implementing water conservation measures and expanding the water use by organizing “water weeks” regularly, which should include exhibitions, lectures, film shows, distribution of relevant literature and poster displays, emphasizing the methods of conservation to be used and the action taken by the department in this regard, the treated water quality and the water reuse practices in Doha and elsewhere. For the present water reuse should be limited to landscaping along the roads and irrigation of farms for growing animal fodder.
Reuse of Treated Wastewater in an Artificial Stream (‘Seseragf') in Kawasaki City, Japan
Authors: Kuribayashi S.
Published: May 2018

Kawasaki City intends to reuse treated wastewater from a sewage treatment plant as the water source for an artificial stream (called a ‘seseragi') in the Kawasaki Aqua-promenade which is to be constructed on the riverbed of the dried-up River Egawa. This paper describes the results of a study on the acceptability as the stream source of four types of treated wastewater. Short streams built in the Kase Sewage Treatment Center were used for the experiments.

Stream water quality requirements include factors affecting appearance, public health, and existence of aquatic life. In other words, growth of attached algae should be inhibited, pathogenic organisms should be at an acceptable level (as indicated by number of coliform bacteria), and the stream should be a suitable habitat for fish. In this paper, the acceptability of the treated wastewater is discussed from these three points of view.

Four types of treated wastewater were investigated, i.e., effluents from a conventional activated sludge process, a biological phosphate removal process, a biological phosphate removal process with post chlorination (addition of sodium hypochlorite), and a biological phosphate removal process with post ozonation.

It was concluded that treated wastewater from the biological phosphate removal process with post ozonation was the most suitable as the water source of the artificial stream (‘seseragi'), when the three requirements mentioned above were considered in conjunction with the influence of the disinfection method on the aquatic environment.
Fish Processing Wastewater: Emission Factors and High Load Trickling Filters Evaluation
Authors: Battistoni P. , Fava G. , Gatto A.
Published: May 2018

An Italian seafood factory processing frozen fish and fresh clams was investigated. Specific water consumption (SC) and pollutant emission factors (EF) are evaluated. Results evidence high SC values, in the range 18-74 1/Kg, due to defrost and extensive washing and cleaning practised; EFs appear high although not directly comparable with data reported by other authors. Two high-rate trickling filters, cross flow (CF) and vertical flow (VF), are examined over a two years period. Results suggest a pseudo half-order kinetic reaction with a superior performance of CF plastic media. From the elaboration of the experimental data a semiempirical correlation between specific surface removal (SSR) and operative parameters is obtained.
Treatment of Wastewater from the Textile Industry
Authors: Nicolaou M. , Hadjivassilis I.
Published: May 2018

Textile wastewater (200 m3/d, 240 kg COD/d, 60 kg BOD5/d) is treated by chemical coagulation - precipitation, followed by activated sludge plant with an oxic selector and a high-rate multilayer coagulation - filtration and disinfection. Treated water is reused for irrigation.
The Use of Zeolite for Ammonium Uptake
Authors: Haralambous A. , Maliou E. , Malamis M.
Published: May 2018

In most countries today the removal of ammonium ions from effluents has become almost a necessity. In this work, studies are presented which demonstrate that natural zeolites and namely clinoptilolite may be effectively used for the removal of ammonium ions. The kinetic studies performed, the isotherms of the ion exchange equilibrium and the calculated separation factor show that clinoptilolite is very selective towards ammonium ions. Also, an attempt is made to study the effect of clinoptilolite pretreatment on its ion exchange capacity for the removal of ammonium ions. Experimental results show that repeated pre-treatments sufficiently improve the zeolite's properties, and the structure of clinoptilolite remains unchanged during the loading and the regeneration cycles. It is concluded that the use of zeolite is an attractive and promising method for ammonium removal.
Chlorophenol Degradation under Oxic and Anoxic Conditions
Authors: Puhakka Jaakko A. , Shieh Wen K. , Järvinen Kimmo , Melin Esa
Published: May 2018

The degradation of 2,4,6,-trichlorophenol (2,4,6-TCP), 2,3,4,6-tetra-chlorophenol (2,3,4,6-TeCP) and pentachlorophenol (PCP) was evaluated in oxic fluidized-bed reactors. The pseudo-steady-state reactor operation at a hydraulic retention time of 5 hours and feed concentrations of 54 mg/l of 2,4,6-TCP and 64 mg/l of 2,3,4,6-TeCP resulted in stable and effective removal performances on these compounds. GC/MS results indicated over 99 % removal of both 2,4,6-TCP and 2,3,4,6-TeCP. However, PCP degradation at 74 mg/l feed concentration was neglible under these conditions. Further, a denitrifying biofilm was developed which was able to use 4-chlorophenol (4-CP) as the sole electron donor in denitrification reactions. No anoxie biofilm able to degrade 2,4-dichlorophenol (2,4-DCP) or PCP degradation in the presence of potassium nitrate could be developed.
A Comparison of 1988-1990 Flavor Profile Analysis Results with Water Conditions in Two Northern California Reservoirs
Authors: Seligman K. , Enos A. K. , Lai H. H.
Published: May 2018

Flavor Profile Analysis (FPA) results were compared with water quality data for two storage reservoirs of the East Bay Municipal Utility District in Oakland, California to determine what conditions exist at the time of an earthy or musty taste and odor episode. Strong musty and earthy aromas coincided most frequently with fall Anabaena sp. blooms and summer Anacystis sp. blooms. Occasional Aphanizomenon sp. blooms were concurrent with Anabaena sp. blooms, so odor problems associated with Aphanizomenon sp. could not be distinguished. Geosmin concentrations of 30-140 ng/L were found in water containing 100,000-300,000 Anabaena sp. cells/100 mL, but 2-methylisoborneol concentrations never exceeded 25 ng/L. Both reservoirs experienced relatively odorless large spring diatom blooms resulting in high chlorophyll a concentrations, so chlorophyll a alone did not serve as a helpful indicator of imminent odor problems. Fall cyanobacteria blooms closely followed the onset of reservoir destratification, so weekly temperature and dissolved oxygen depth profiles successfully predicted the start of a cyanobacteria bloom. Musty and earthy odors in the filter plant effluent were lower than those in the influent, but effluent FPA numbers reached 4 during two large taste and odor episodes, suggesting that granular activated carbon installed 1-2 years earlier may not remove all odor-causing compounds of a large taste and odor episode.
Characterization of Drinking Water Odour Arising from Spring Thaw for an Ice-Covered Upland River Source
Authors: Hrudey S. E. , Rector D. , Motkosky N.
Published: May 2018

Recurring odour events during spring thaw in the North Saskatchewan River led to a program to characterize contributing odour agents. Raw and treated water samples were adsorbed on granular activated carbon which was then exhaustively solvent extracted. The solvent concentrates were subjected to a Chromatographie sniffing procedure combined with gas chromatographic-mass spectral analyses. Geosmin and 2-methylisoborneol were identified by sensory and analytical means as likely major contributors to the raw water odour. Benzaldehyde, camphor and dihydroactinidiolide were other relevant compounds identified. Given the near freezing water conditions at the time of the odour event, the biogenic source of the odour agents remains a subject for investigation.