bluuebunny/crossref_metadata_2025_split huggingface dataset:
ON-LINE FLUX-THEORY BASED CONTROL OF SECONDARY CLARIFIERS
Authors: Balslev Peter , Nickelsen Claus , Lynggaard-Jensen Anders 
Published: May 2018

A strategy for controlling secondary clarifiers during dry weather and rain is described. The strategy is now implemented and is being tested on a full-scale wastewater treatment plant. The plant - Aalborg West Wastewater Treatment Plant - is operated by using the patented Biodenipho process.
The flux theory as formulated by A. Vesilind, in combination with measurements of sludge level, suspended solids and flow at critical points, form the bases for a dynamic on-line control of the clarifiers. The settling velocity used in the flux theory is measured and calculated on the basis of the installed sensors. In the test period it is expected that the control strategy will show capability of several improvements compared to traditional control strategy. The dry weather strategy should result in a reduction of return sludge pumping and thereby save energy. Moreover, improvement of the sludge characteristics is expected because of less pumping of sludge.
The rain strategy should show possibility of significant reduction in storm overflows in the plant and in the sewer system upstream to the treatment plant. Thereby the capacity of the plant will be improved and the total effluent load to the recipient reduced.
MODELLING OF OXYGEN TRANSFER IN DEEP DIFFUSED-AERATION TANKS AND COMPARISON WITH FULL-SCALE PLANT DATA
Authors: Pöpel H. Johannes , Wagner Martin 
Published: May 2018

In upgrading or extending activated sludge treatment plants, there is a trend to apply deeper (8 to 12 m) aeration tanks than until now (4 to 6 m). Such tanks consume less area, need less air and produce less off-gas. Sometimes, a greater aeration efficiency (kg O2/kWh) and hence energy savings are expected. On the other hand, there is not sufficient experience to safely design air diffusion systems for deep tanks.
Based on the physics of gas transfer, a model for simulation of oxygen transfer in deep tanks is developed. The simulated data allow quantitative conclusions with respect to the potential advantages stated above. According to the model, a reduction of the required air flow is considerable up to depth of some 15 m but energy savings cannot be expected. The model is verified using 98 full-scale plant measurements at various tank depths. The comparison shows a good agreement between simulated and actual data. Further investigations are required to support the model at greater depth and to enable a safe design procedure for air diffusion systems in deep tanks.
Constructed “Source” Wetland Concepts Applied to Urban Landscapes
Authors: Hopkins Ben , Argue John R. 
Published: May 2018

A class of wetland is introduced which employs engineering practices and installations to collect, store, dispose of, retrieve and use stormwater, at source, in the urban landscape. Two Adelaide (South Australia) examples of “source wetlands” are described. At New Brompton Estate, roof runoff from (eventually) a cluster of 15 residences is diverted to a 106 m gravel-filled trench in a central reserve. The collected water sustains a row of deciduous trees bordering the reserve and provides frequent (winter) charges, via a bore, to a Quaternary aquifer at depth 30 m.
At Northfield a swale/trench system which handles all storm runoff from a residential street (including domestic contribution) will be trialled. Runoff seeping to the trench from the swale will be of high quality and will provide charges of water to a 5 m Quaternary aquifer. Some runoff of good quality will pass from the catchment in large storm events. In both cases, New Brompton and Northfield, water retrieved from the Quaternary aquifers in summer will be used for open space irrigation. Constructed source wetlands offer a valuable new option in urban stormwater quantity/quality management.
The Use of Constructed Wetlands for Treating Industrial Effluent (Textile Dyes)
Authors: Davies T. H. , Cottingham P. D. 
Published: May 2018

Constructed wetlands bave the capability to treat industrial wastewater containing a wide range of chemicals, including priority pollutants such as phenols and cresols, by processes such as absorption and bacterial breakdown, chemical oxidation, adsorption onto the bed matrix and sedimentation. A brief overview of this technique is presented along with details of preliminary trials carried out on textile dyeing and processing water.
The trials were conducted in a horizontal flow, gravel bed reed (30m × 5m), located in Melbourne, Australia. The textile dye wastewater was applied at an influent rate of 10 1/min., resulting in a retention time in the reed beds of 3–4 days, results indicated that breakdown of the visible dye occurred mainly in the first one third of the bed.
AUTOMATED RESPIRATION INHIBITION KINETICS ANALYSIS (ARIKA) WITH A RESPIROGRAPHIC BIOSENSOR
Authors: Kong Z. , Vanrolleghem P. , Verstraete W. 
Published: May 2018

Respirometric techniques have been used for the on-line and off-line assessment of toxic effects of substances. A model-hased method to describe toxic effects on the biodegradation kinetics based on a respirometric technique has been developed by Volskay and Grady, However. this so-called RIKA-procedure (Respiration Inhibition Kinetics Analysis) is rather laborious and time consuming.
In this paper, a fast and automated method will be presented which allows us to perform the RIKA test within 3 hours by using an activated sludge based respirographic biosensor (RODTOX, Rapid Oxygen Demand and TOXicity tester). These results could be achieved because a respirogram obtained from this biosensor gives rise to a degradation rate versus substrate concentration data-set that covers the whole substrate concentration range required by the RIKA test. Starting from an initial concentration of 20 mg COD/1 in the ARIKA procedure, the biogenic substrate is degraded completely in less than 30 minutes. Using a model-based approach coupled to a non-linear parameter estimation algorithm. the kinetic parameters of the biodegradation process can be obtained. Performing batch tests with different toxicant concentrations (usually 4) then allows us to deduce the dependence of the kinetic parameters on the toxicant concentrations. Since the method is automated, the procedure is fast and labour-saving.
MONITORING OF THE MAXIMUM RESPIRATION RATE
Authors: Spanjers Henri , Temmink Hardy , Klapwijk Abraham 
Published: May 2018

The maximum respiration rate is useful for estimating the active biomass concentration and detecting toxic effects on the activated sludge. In this paper we describe a method for continuously measuring the maximum respiration rate of sludge in an activated sludge plant. The method is based on the continuous addition of wastewater into sludge flowing through a respiration chamber. The measurement is verified, at regular intervals, by stepwise increasing the wastewater sample flow to the respiration chamber whilst recording the respiration rate.
The results of a measuring period at a pilot plant are presented. The influent flow to this plant was varied according to a square wave pattern with a period of 12 hours. The maximum respiration rate was monitored and during each period the measurement was verified.
The verifications show that the wastewater sample flow applied was sufficiently high to attain saturation with respect to the substrate concentration. It was concluded that in both periods the maximum respiration rate was really measured. The experiment was repeated several times during another measuring period. It was found that saturation was not always achieved at the wastewater sample flow applied and thus the maximum respiration rate was not measured in these cases. Explanations are given and suggestions for improvement of the measurement are provided.
Source reduction and recycling for pollution prevention in chemical plants
Authors: Ansari M. A. 
Published: May 2018

This paper reviews and describes the methods currently used to reduce water pollution from chemical plants using waste minimization at the source and recycling when necessary.
Techniques, including process changes, equipment modifications, changes in operational set points, improved process control and automation are discussed.
The discussion focuses on AlliedSignal's successful experience using techniques of total quality management in reducing pollution at the source and through recycling. Examples are presented as to how management's commitment to waste minimization concepts, operator training and involvement, and team work helped in reducing significant plant's effluent emissions.
Biological Foams: The Cause-Effect Relationship, Test Results and Combat Strategy
Authors: Duchene Ph. 
Published: May 2018

This paper presents the results obtained by “G.I.S. MOUSSES”, which comprises the CEMAGREF and the six main private companies operating wastewater treatment plants (WWTP) throughout FRANCE.
Over 75% of French activated sludge (AS) WWTP, 20% are reported to be affected by foaming. 60% of theseare linked with Microthrix and only 14 % with Nocardioforms. Few factors conducive to foaming were statistically proved. Experiments run on more than 40 AS WWTP helped us to identify cause-effect relationships and useful methods to reduce foaming, varying with the type of dominant hydrophobic filamentous microorganisms. The finer points related to design and operation are identified in order to be effective against foaming.
Depending on the type and degree of urgency of each case, different combat strategies are proposed.
Profitability Increase of Alcohol Distilleries by the Rational Use of Byproducts
Authors: van Haandel Adrianus C. , Cavalcanti Catunda Paula Frassinetti 
Published: May 2018

Industrial alcohol production in Brazil is based on fermentation of sugar cane juice. After centrifugation and distillation, azeotropic alcohol is obtained along with four side streams: (1) bagasse, the solid part of the cane plant, (2) yeast, grown during the fermentation, (3) carbon dioxide released during the fermentation and (4) waste water called vinasse composed of the bottom fraction of the distillation and wash waters. The profitability of alcohol distilleries can be improved by a more rational use of the side stream products. The solid products have a diversified application potential. By applying anaerobic digestion to vinasse, methane can be produced at a proportion of 100 kgCH4 per m3 of produced alcohol. Full scale application has shown anaerobic digestion to be technically and economically feasible and the digested waste water can be used for irrigation, whereas the produced solids can be applied as soil conditioners.
An alternative for improved energy production is to abandon alcohol fermentation and apply anaerobic digestion directly to the vegetal energy source. In that case the useful energy production is much higher and can be obtained using much simpler equipment. More importantly, the source for energy production would no longer be restricted to cane: Other crops, notably those produced in the drier hinterland of North East Brazil (cassava, sweet potatoes), could also be used for this purpose.
Neutralization of Acid Mine Water with Calcium Carbonate
Authors: Maree J. P. , du Plessis P. 
Published: May 2018

Traditionally, lime is used for the neutralization of acidic effluents. Calcium carbonate should be considered as an alternative because of considerations such as lower cost, low solubility at pH values greater than 7 and simple dosing system required. The paper describes a pilot scale study to determine the technical feasibility of neutralising sulphuric acid-rich water using fluidised bed technology.
Limestone was utilised completely when testing iron(III)-rich water, but with iron(II)-rich water, coated limestone particles accumulated in the fluidised-bed reactor. About 70% of the limestone was utilised in the case of water containing 600 mg/l iron(II).
A contact time of 4 min was sufficient for the neutralization of acid water containing 4 g/l free acid and 580 mg/l iron(III), compared to 40 min when iron(II) replaced iron(III).
Anaerobic Treatment of Industrial Wastewater Containing Organic Solvents
Authors: Terzis Evangelos 
Published: May 2018

Industrial water usage results in large volumes of liquid wastes rich in organic pollutants. Waste waters from certain industrial chemical operations (e.g. organic synthesis, perfume industry) will sometimes contain organic solvents at relatively high concentrations. The presence of organic solvents is undesirable in the sewerage system and so must be removed from the industrial effluent. Anaerobic treatment of many of these organic solvents is possible, in which the organic material is converted ~90% to volatile substances -carbon dioxide and methane gas- and ~10% to new bacterial cells (solids). Industry will be using less water in the future. Increased water charges will lead to more precise control and integrated processes will reduce wastage. The smaller volumes of more concentrated waste will be ideal for anaerobic digestion.
In order to evaluate the optimum conditions for the anaerobic digestion of propan-2-ol (iso-propanol) the kinetic parameters of the Monod rate model, namely, maximum growth rate (µm), yield (Y), half velocity constant (Ks) and endogenous decay coefficient (Kd), were determined at the temperature range 25°-40°C, inclusively. The regulatory role of molecular hydrogen was investigated and discussed, and also its possible use as a monitor feature in the anaerobic digestion.
A simplified procedure for setting effluent quality standards
Authors: Espino de la O Ernesto , Limón M. Gualberto , Escalante Ignacio Castillo 
Published: May 2018

The discharge of untreated effluents affects the quality of receiving water bodies and impairs their potential beneficial uses; to prevent this from happening, effluent quality standards (EQS) must be set. The conventional procedure for establishing EQS requires extensive knowledge of the receiving body characteristics. When there is an evident need for setting EQS, but all the information needed is not available (a situation probably common to many regions around the world), the need arises for a simplified procedure, such as the one herein proposed. The procedure is based on four tenets:
1) the classification of major water quality parameters into four classes: basic parameters, conservative contaminants, toxic contaminants and pathogens;
2) various sets of maximum permissible contaminant concentration (MPCC), for each class of contaminants;
3) two comprehensive classifications: one of effluent discharges according to their origin, and another of receiving waters based on their intended use and general characteristics; and
4) a two-dimensional matrix for different classes of effluent discharges and receiving bodies; four indices are proposed for each cell of the matrix, specifying MPCC for each class of parameters.
Process optimisation for simultaneous biological nitrification and chemical phosphorus removal
Authors: Bliss P. J. , Ostarcevic E. R. , Potter A. A. 
Published: May 2018

Environmental regulations require sewage treatment plants originally designed for BOD and suspended solids removal to meet increasingly stringent effluent ammonia and total phosphorus standards. Operating a biological nitrification process in parallel with chemical phosphorus removal to achieve consistent effluent concentrations less than 1mg/L was successfully achieved through process optimisation.
An optimisation program was developed and implemented which effectively allowed the combination of two essentially conflicting processes to produce high quality effluent. The process optimisation program utilised a structured approach to identify process deficiencies which reduced treatment capacity and reliability. Accurate identification of process deficiencies enabled appropriate solutions to be developed and implemented. Additional monitoring quantified improvements arising from process modifications or revised operating procedures.
The average effluent ammonia concentration between June and September 1990 was 23.8mg/L. This was reduced to 0.6mg/L after optimisation in October 1992. The standard deviation of 3.4mg/L during the baseline monitoring program between February and April 1992 was reduced to 0.4mg/L after optimisation, at much lower mixed liquor temperatures. Similarly, the average effluent phosphorus concentration was reduced from 1.1mg/L with a standard deviation of 0.8mg/L to an average value of 0.6mg/L with a standard deviation of 0.3mg/L.
Understanding process operations, combined with the ability to identify process deficiencies resulting from poor operating practices and environmental conditions, reduces the risk of generating poor effluent quality. The performance of any treatment process can derive significant benefits by implementing an effective process optimisation program. This work established that reliable process performance is possible, provided that process deficiencies are identified, and appropriate solutions are implemented and evaluated.
Upgrading of activated sludge systems for nitrogen removal by application of the LINPOR®-CN process
Authors: Morper M. R. 
Published: May 2018

LINPOR®-systems are modified activated sludge plants, where the aeration tanks contain a certain quantity of highly porous plastic foam particles, which serve as a carrier material for active biomass. Thus a substantial performance improvement is achieved as compared to conventional activated sludge systems without having to renounce the well proven elements of the activated sludge technology.
The LINPOR®-CN process for the simultaneous elimination of organic and nitrogen pollutants is particularly suitable for upgrading existing plants, because it can be made to fit into existing tanks with no or only little change of the once installed facilities.
Granule production from raw waste activated sludge
Authors: Noyola Adalberto , Moreno Gloria 
Published: May 2018

Granulation is an important characteristic of sludges used in upflow anaerobic sludge blanket (UASB) reactors. As the UASB technology is rapidly spreading, there is a need of granular sludge for inoculation of new reactors, particularly in those countries where anaerobic technologies have been just recently accepted.
Alternative sources of inocula are digested sludge, digested manure, septic tank sludges and pond sediments. Raw waste activated sludges have also been identified as a convenient material for reactor seeding, with previous treatment.
In this work, anaerobic flocculant sludge obtained from raw waste activated sludge has been granulated with hydraulic stress, in a lab-scale column under different upflow velocities (1 to 50 m h−1). A methodology is proposed for enhancing the quality of non granular anaerobic sludges in batch treatments of less than 8 hours. The granular sludge produced was used as inoculum for a UASB lab scale reactor. The seed sludge improved all its characteristics and maintained the granulation, in spite of the low velocity (0.08 m h−1) applied.
Experiences gained in the operation of anaerobic treatment plants in Germany
Authors: Austermann-Haun U. , Seyfried C.F. 
Published: May 2018

In the western part of Germany there are 77 full scale anaerobic treatment plants treating industrial wastewater. The ISAH (Institut für Siedlungswasserwirtschaft und Abfalltechnik at the University of Hannover) is or was involved in the investigations, the design and/or operation of 14 of these plants. Some industries (sugar beet, starch, pectin, brewery, vegetable) with their special problems with treating their wastewater anaerobically are described. Experiences of how to handle high nitrate concentrations, to treat a mixture of several industrial wastewaters, to prevent or handle lime, magnesium ammonium phosphate (MAP) or aluminium precipitations are reported.
The first municipal wastewater treatment plant combined with a separate anaerobic stage to treat a wastewater mixture of several small factories is described. Something very special about this plant is the construction of the acidification tank. Using the “teapot effect” to enrich the solid material in the centre of the bottom, the solids can be taken from the bottom of the tank and pumped to the municipal sludge digester.
Influence of Bleaching Conditions and Membrane Filtration on Pilot Scale Biological Treatment of Kraft Mill Bleach Plant Effluent
Authors: Frostell Björn , Boman Bengt , Ek Mats , Palvall Björn , Berglund Marie , Lindström Anders 
Published: May 2018

A kraft mill bleach plant effluent was treated in a pilot station with a common pretreatment stage and three parallel biological treatment plants. The possibility to membrane filter the E-stage effluent before biological treatment was provided. In the first pilot plant, three 0.7 m3 anaerobic fixed film reactors were followed by an activated sludge plant with two 0.7 m3 aerobic tanks in series. The second plant comprised a 10 m3 anaerobic hybrid reactor followed by a 2.5 m3 activated sludge plant. The third line was a 4.5 m3 activated sludge plant. All three plants were connected on-line to the bleach plant in a kraft mill. During the study, the bleaching conditions were changed from 75% substitution of chlorine for chlorine dioxide to 100% chlorine dioxide bleaching. In the comparisons, a total hydraulic retention time of 12 hours was used in all the three systems. The influent temperature was kept at 37-38°C. Biomass concentrations were 1.5-4 kg TSS/m3 in the aerobic parts. The concentration of fixed biomass was estimated to be 10-20 kg/m3 in the anaerobic reactors after the experiments.
The change in bleaching conditions decreased the discharge of AOX more than 50% and had a positive effect on the biological treatability of the bleach plant effluent. The transformation of organic and chloroorganic material increased, a more stable operation could be obtained and the quality of the sludge improved. Except for chlorate, there were no major differences in treatment efficiency between the three systems studied. Anaerobic pretreatment resulted in a somewhat higher AOX removal and a somewhat better tolerance to shock loads, especially with chlorine used in bleaching. Membrane filtration of the E-stage effluent gave a significant contribution to the overall treatment result with 75% chlorine dioxide (D) in the first bleaching stage, but contributed only marginally with 100% D.
Clarifier Performance in Activated Sludge Process Treating Pulp and Paper Mill Effluents
Authors: Halttunen Sakari 
Published: May 2018

High suspended solids concentrations are typical for pulp and paper industry treated effluents. A new clarifier model was developed to find the reasons for this problem. The model clarifier is divided into four different zones: inlet, settling, thickening and separation. In the inlet zone sludge is transported by water flow and neither thickening nor settling will happen. When water velocity decreases the main part of the sludge will settle until it reaches the thickening zone. Thickening will continue until the sludge is pumped away from the clarifier. Concentration increase depends on sludge concentration, time and specific thickening coefficient. The minor part, which is specific to the sludge, enters the separation zone and will either settle in the thickening zone or stay in the effluent.
In intensive field studies on 12 different activated sludge processes sludge volume in the clarifier, effluent suspended solids concentrations and sludge settling qualities were examined. Modelled sludge blanket volumes were verified with blanket measurements. Modelled effluent suspended solids were also verified by concentration measurements.
Sludge thickening characteristics can be estimated by DSVI. From the data collected two empirical relationships were noticed between sludge settling properties and process operation. Solids concentration in clarified water depends on settling number, which is the mean number of sludge settling during its residence time in the process (sludge age). Sludge settling properties seem to depend on collision load, which is defined as COD-load divided by return sludge biomass flow.