bluuebunny/crossref_metadata_2025_split huggingface dataset:
Model development and full scale validation for anaerobic treatment of protein and fat based wastewater
Authors: Batstone Damien , Keller Jürg , Newell Bob , Newland Mark 
Published: May 2018

Presented is a kinetic model simulating the biodegradation of pig abattoir (slaughterhouse) wastewater in a full scale anaerobic treatment plant. High rate anaerobic treatment of these wastes is often complicated by the presence of particulates and fats. The model developed by Costello et al. (1991) for the degradation of soluble carbohydrates and modified by Ramsay et al. (1994) for soluble proteins is further expanded to simulate the solublisation of particles and the biological degradation of fats. This approached proved well suited to describe the full breakdown of the complex component mixture found in such a wastewater.
The model is tuned using one dynamic experimental run and is validated against on two different experimental runs. Agreement between simulation and experimental results is very good on all sets of data. The importance of critical outputs such as gas production and agreement between experimental and simulation results are discussed. It is concluded that the model should be a useful tool for optimal reactor design and operation when encountering difficult wastewaters.
A cost effective approach to stormwater management? source control and distributed storage
Authors: Andoh R. Y. G. , Declerck C. 
Published: May 2018

Rapid urbanisation and its consequent increase in impermeable surface areas and changes in land use has generally resulted in problems of flooding and heavy pollution of urban streams and other receiving waters. This has often been coupled with ground water depletion and a threat to water resources.
The first part of this paper presents an alternative drainage philosophy and strategy which mimics nature's way by slowing down (attenuating) the movement of urban runoff. This approach results in cost-effective, affordable and sustainable drainage schemes. The alternative strategy can be described as one of prevention rather than cure by effecting controls closer to source rather than the traditional approach which results in the transfer of problems downstream, resulting in its cumulation and the need for large scale, centralised control.
The second part describes a research project which has been launched in order to quantify the cost and operational benefits of source control and distributed storage. Details of the methodology of the modelling and simulation processes which are being followed to achieve this target are presented.
Energetics of enhanced biological phosphorus and nitrogen removal processes
Authors: Tonkovic Zlatko 
Published: May 2018

Recent advances by researchers with in vivo NMR spectroscopy using labelled isotopes of carbon and phosphorus have elucidated some of the biochemical pathways involved in enhanced biological phosphorus and nitrogen removal processes. This has permitted a greater understanding of carbon and phosphorus cycling within cellular processes.
All microbiological processes associated with energy transformations are dependent on enzyme induction. The enhanced phosphorus removal apparatus in certain organisms is dependent on the environmental conditions in order to induce the necessary enzymes. Enzyme expression has been linked to redox potential, which itself is a function of the culture medium and the bioenergetic condition of the cells. Redox balance is coupled to several pathways in the metabolic network of microorganisms. Changes to the redox potential result in shifts in the metabolic pathway utilisation.
In the past, nitrification and denitrification have been thought to be strictly aerobic and anoxic processes respectively. Mounting evidence has demonstrated that this classical view of nitrification and denitrification is no longer valid and that other processes can occur such as simultaneous nitrification and denitrification and aerobic denitrification. Enzyme induction plays a very important role in these processes.
Attempts have been made in this paper to elucidate the energetics of anaerobic phosphorus release based on cellular composition and various other plant operating parameters. Energetics of the denitrification process including anoxic dephosphatation, aerobic denitrification, with potential reduction in aerobic treatment requirements, are also explored.
Application of constructed wetlands for domestic wastewater treatment in an arid climate
Authors: Mandi L. , Bouhoum K. , Ouazzani N. 
Published: May 2018

The present study consists in assessing the efficiency of a constructed reed bed for domestic wastewater purification under an arid climate. The experimental system is made up of four beds differing in length (20, 30, 40 and 50 m) and planted with Phragmites australis. Raw domestic wastewater inflow through these beds is horizontal with a flow of 10 litres per second. Hydraulic application rate varies between 0,86 to 2,16 m3.m−2.day−1. The frequency of irrigation is weekly. The studied parameters are: the organic load (COD and TSS), nutrients (total Kjeldhal nitrogen: TKN, NH4, total phosphorus: TP, PO4) and the parasitical load (helminth eggs).
Results shows that the constructed reed beds are efficient in reducing organic load (TSS: 58% to 67%; COD:48% to 62%) and parasitical load (Helminth eggs: 71% to 95%) in arid climates even with high hydraulic application rate. However, reduction of nutrient concentrations by the four beds is slight (TKN: 23 to 43%; NH4: 18 to 41%; TP: 5 to 17%; PO4: −9 to 13%). At the hot period (March to August), the reed beds seem to be more efficient in reducing organic load, nutrients and parasitical load. This period coincides with the reed's exponential growth phase. Moreover, the largest bed (50m in length) showed the best efficiency in the removal of nutrients (TKN: 53%; NH4: 61%; TP: 30%; PO4: 14%) and parasitical load (helminth eggs: 99%). This is due to its lowest application rate (0,86 m3.m−2.day−1).
Application of computational fluid dynamics technique to storage reservoir studies
Authors: Ta C. T. , Brignal W. J. 
Published: May 2018

The flow dynamics in Grimsbury reservoir is studied using Computational Fluid Dynamics (CFD). Under no wind condition, flows circulate in the horizontal plane. These circulations, in general, lead to short circuiting and zones of stagnation. Modifications to the inlet and the outlet are investigated to maximise the residence time. They include the manifold inlet arrangement, the submerged baffle inlet and the central outlet arrangement.
The results of the residence time simulation indicate that the manifold inlet option gives the best ‘plug-flow’ efficiency, next the submerged baffle option and finally the central outlet option. The submerged baffle inlet option, however, is considered to be the preferred option because of its low installation cost and because of the reasonable balance between the degree of mixing and the residence time.
Development of water quality management strategies for the proposed isikli reservoir
Authors: Gündüz Orhan , Soyupak Selçuk , Yurteri Coskun 
Published: May 2018

A two-dimensional laterally averaged hydrodynamic and water quality model (CE-QUAL-W2) is used to simulate the water quality behavior in the proposed Isikli Reservoir of the Ankara Water Supply System to determine appropriate strategies for the management of water quality.
Isikli application of the model is used to demonstrate the potential water quality degradation patterns in the reservoir under different pollution loads. The results of the modeling study are compared with the drinking water quality standards currently effective in Turkey to formulate various water quality management strategies for the reservoir and its catchment area. In addition, various treatment options are evaluated considering the existing treatment system of Ankara City.
Based on the findings of this study, treatment or interception of wastewaters originating from the existing pollution sources around the reservoir area are introduced as the major infrastructural control techniques. Further, establishment of protection zones around the reservoir and relocating the possible pollution sources to a point downstream of the dam axis are found to be the most applicable administrative control methods for water quality preservation in the proposed reservoir.
A generalized settling approach in the numerical modeling of sedimentation tanks
Authors: Mazzolani G. , Pirozzi F. , d'Antonoi G. 
Published: May 2018

Numerical models for the prediction of turbulent flow field and suspended solid distribution in sedimentation tanks are characterized by refined modeling of hydrodynamics, but apparently weak modeling of settling properties of suspensions. It is known that sedimentation tanks typically treat highly heterodisperse suspensions, whose concentrations range from relatively high to low values. However, settling is modeled either by considering one or more particle classes of different settling velocity, without accounting for hindered settling conditions, or by treating the suspension as monodisperse, even in regions of low concentration.
A new generalized settling model is proposed to account for both discrete settling conditions in low concentration regions of the tanks and hindered settling conditions in high concentration regions. Settling velocities of heterodisperse suspensions are then determined as a function of particle velocities in isolation and their total concentration. The settling model is used in the framework of a transport model for the simulation of hydrodynamics and solid distribution in a rectangular sedimentation tank. Results show that solid distribution is mainly affected by particle interactions in the inlet region and by settling properties of individual particles in the outlet region. Comparison of the proposed settling model with other settling models suggests that a generalized approach of the modeling of settling properties of suspensions is a primary concern to obtain reliable predictions of the removal rate.
Process audit and asset assessment using on-line instrumentation
Authors: Watts John B. , Cavenor-Shaw Andrew R. 
Published: May 2018

The traditional approach to assessing the performance of an Activated Sludge Plant (ASP) is to conduct an expensive and often labour intensive through-plant sampling survey. The results from this kind of survey do not give an accurate picture of the plant performance in real time, and often can be ruined by inaccurate or spoilt analytical results.
A new approach to Process Audits has been developed based on on-line instrumentation and remote monitoring. The key equipment required to dynamically monitor the ASP performance is the MSL Respirometer which is used to measure organic loading, required retention time and aeration system requirements.
Auto-cleaning, auto-calibrating Dissolved Oxygen sensors are used in conjunction with a Respirometer to assess the aeration system efficiency (actual Kla value) and the maximum oxygen demand (OUR) which can be sustained by the plant. Ultrasonic flow meters are used to determine flow splits and actual plant retention time which is compared to the required retention time measured by the Respirometer. Mixed Liquor Suspended Solids (MLSS) profiles are monitored continuously using a self-cleaning optical sensor, which is used along with Respirometric readings to measure the effect of poor wastage regimes and ingress of inert solids. On-line ammonia, phosphate and nitrate monitors can be used to give information on the diurnal variation of nutrients, related to the loading on the plant. As well as the normal plant operation, the effect of shock loads, storm conditions and sludge liquor returns can all be assessed.
All instruments are linked via a serial communications loop to a modern and telephone line. The plant is monitored remotely, making it an unobtrusive survey allowing operations to continue as normal and giving a true picture of the plant performance.
This approach has been used on several UK sewage treatment works and has proven to be a cost-effective method. In one case a proposed capital spend on final settlement tanks was shown to be unnecessary; in another case the plant was shown to be unable to support a nitrifying biomass.
On-line nitrification inhibition monitoring using immobilised bacteria
Authors: Hayes E. , Upton J. , Batts R. , Pickin S. 
Published: May 2018

As wastewater treatment plant managers are required to meet increasingly stringent standards the focus on processes has shifted more and more towards assessing the treatability of a waste. Many substances discharged to effluent treatment plants may inhibit the process of nitrification. Traditional testing methods are costly and cannot be used for real time control which has led to the development of the AmtoxTM system.
AmtoxTM uses a culture of immobilised nitrifying bacteria in a system maintained at 30°C. This enhances the rate of nitrification and gives an early warning of toxicity. This paper presents data comparing Amtox with the conventional nitrification inhibition test method and describes the instrument designed for laboratory use. Preliminary data for the on-line Amtox system are also included: these data provide the first, direct, continuous measure of nitrification inhibition on an effluent treatment plant.
Case history - two stage, low-rate anaerobic treatment facility for South American alcochemical/citric acid wastewater
Authors: Wilson D. R. , Page I. C. , Cocci A. A. , Landine R. C. 
Published: May 2018

This paper describes the case history of a two-stage, low-rate anaerobic treatment system at a South American alcochemical and citric acid plant. Environmental concerns associated with land irrigation of a high-strength industrial wastewater forced the plant to implement wastewater treatment. This paper will also outline results from an on-site pilot study which was conducted to develop the design criteria for the full-scale system.
The installed full-scale system will be described in detail, including the plant s physical layout, design parameters, system performance, biogas production and utilization, and some of its unique aspects. Among these is the use of a floating biofilter (bagasse) on the second stage to eliminate any nuisance odours from off gases.
All biogas generated in the first stage is collected, with a significant portion drawn off and burned in a retrofitted 8000 kW boiler to generate process steam. The excess biogas is flared. Effluent from the treatment system is combined with other low-strength process plant streams and discharged to a river.
During the first year of operation, performance has been very good, with chemical oxygen demand (COD), biochemical oxygen demand (BOD), and total suspended solids (TSS) removals averaging 74 percent, 93 percent, and 70 percent, respectively. The corresponding COD, BOD, and TSS results obtained in the pilot study were 74 percent, 96 percent, and 70 percent, respectively, and agree very well with those being obtained in full scale.
Application of tubular ceramic membranes for reuse of wastewater from buildings
Authors: Ahn Kyu-Hong , Song Ji-Hyeon , Cha Ho-Young 
Published: May 2018

This research investigated the possibility of applying ceramic membranes for simple and compact treatment to reuse wastewater generated from hotel buildings for secondary purposes such as toilet flushing water. The tested membranes were ultrafiltration (UF) and microfiltration (MF) membranes of 15 kDa, 300 kDa, and 0.1 mm. Parameters such as transmembrane pressure, crossflow velocity, MWCO/pore size were changed and the performance of the membranes and the quality of the permeate observed.
Since the average particle size of the influent wastewater was 2.18 μm, larger than the pore size of the membranes tested, the effect of MWCO/pore size on the filtration performance was marginal. When a pseudo-steady state was reached, permeate flux increased with increased crossflow velocity. Furthermore, it was better to adopt turbulent flow (Re&gt;20,000) rather than laminar flow in order to maintain constant transmembrane pressure and system stability.
The optimum transmembrane pressure was found to be 150 kPa; a higher pressure will densify the cake layer unnecessarily on the membrane surface which will induce quicker membrane fouling.
When energy consumption was compared, MF with 0.1 μm, which was capable of producing higher permeate flux in the initial phase of experimentation than other tested membranes, was found to be the least energy consuming; the effect of other parameters besides the pore size of the membrane was negligible on the energy efficiency.
The quality of permeates obtained from all the experiments investigated in this research satisfied the guidelines set by the Korea Ministry of Environment for the reuse of wastewater for secondary applications such as in toilet flushing water.
Immersed membranes activated sludge process applied to the treatment of municipal wastewater
Authors: Côté Pierre , Buisson Hervé , Praderie Matthieu 
Published: May 2018

An immersed membrane activated sludge process has been evaluated at pilot scale by Anjou Recherche. This process represents a new generation of hybrid techniques, which aims at coupling biological treatment and membrane filtration functions, in a configuration adapted to the treatment of municipal wastewater.
The process was evaluated under extended aeration conditions, but with concentrations of biomass of between 15 to 25 gMLSS/l, which corresponded to volumetric loadings of between 1.2 to 2.3 kg COD/m3/d. Under these conditions, COD and TKN removal were better than 96% and 95%, respectively. The membrane ensured total removal of suspended solids and produced treated water of excellent bacteriological quality. The sludge production stabilized at 0.20 gDS/kg COD removed. The membrane flux was stable for all conditions tested.
Bioleaching of heavy metals from contaminated aquatic sediments using indigenous sulfur-oxidizing bacteria: a feasibility study
Authors: Seidel H. , Ondruschka J. , Morgenstern P. , Stottmeister U. 
Published: May 2018

The removal of heavy metals from contaminated river sediments was studied using suspension leaching under laboratory conditions and percolation leaching in a pilot plant. The leaching potential of indigenous sulfur-oxidizing bacteria was compared with acid treatment. Bioleaching with elemental sulfur as substrate was found to be better than treatment with sulfuric acid for the solubilization of all metals tested. The physical and chemical properties of the sediments used in this study did not affect leaching capacity under optimum conditions in the laboratory.
Under the practical conditions in the pilot plant, the redox state of sludge had a considerable influence on leaching efficiency. In a deposited oxic sediment with good permeability, about 62% of the metals tested were removed by percolation leaching after 120 days. Zn, Cd, Ni, Co and Mn were sufficiently leached to enable treated sediments to be reused as soil. In a freshly dredged anoxic sediment, only a total of 9 % of metals were removed. The results indicate that freshly dredged sediments need to undergo pretreatment before percolation leaching to improve mass transfer and to activate the leaching active bacteria.
Feasibility of the UASB/AF system for domestic sewage treatment in developing countries
Authors: Chernicharo C. A. L. , Machado R. M. G. 
Published: May 2018

This paper presents the results of three pilot units comprising one UASB reactor followed by two anaerobic filters (AFs) operating in parallel (upflow and downflow modes). The UASB reactor had a volume of 416 litres, being operated at hydraulic retention times (HRT) of 6 and 4 hours. The anaerobic filters had total volumes of 102 litres (32 litres of packing material), being operated at HRT varying from 24 to 1.5 hours (upflow velocities varying from 0.06 to 1.44 m/h). These different operational conditions characterised seven phases of research. Both reactors were fed with domestic sewage pumped directly from the main interceptor of Belo Horizonte city – Brazil.
After almost one year of continuous monitoring, the UASB/AF system produced very good results in terms of COD and BOD removal, and also very low solids concentration in the final effluent. The average results of COD and BOD removal varied from 85 to 95%, sufficient to maintain the COD concentration in the final effluent in the range of 60 to 90 mg/l and the BOD values systematically below 40 mg/l. The overall averages of SS in the final effluent were kept below 25 mg/l.
The UASB/AF system could become a very promising alternative for the treatment of domestic sewage in developing countries, since the system can be designed at very short hydraulic retention times (6 hours for the UASB reactor and 3 to 4 hours for the AF), resulting in a very compact and low cost treatment unit. Besides, there is no energy consumption and the labour costs are minimum.
Biological phosphorus and nitrogen removal in a full scale sequencing batch reactor treating piggery wastewater
Authors: Tilche A. , Bacilieri E. , Bortone G. , Malaspina F. , Piccinini S. , Stante L. 
Published: May 2018

Research activities carried out at ENEA during the last few years allowed the development of a Sequencing Batch Reactor (SBR) that is able to remove biologically organic waste, nitrogen and phosphorus and that was shown to be particularly suited to obtaining low effluent nutrient concentrations even starting from concentrated wastes. Research on optimisation of time cycles and on process modelling, allowed an advanced comprehension of reactor behaviour and the development of a process able to obtain more than 98% removal of nitrogen, phosphorus and COD, and therefore almost capable of matching effluent standards with a sole biological process.
On the basis of laboratory results and process modelling, a full scale SBR plant has been designed and realised. This plant, in ten months of operation, is achieving even better results compared to the laboratory ones.
Design Recommendations for Subsurface Flow Constructed Wetlands for Nitrification and Denitrification
Authors: Platzer Christoph 
Published: May 2018

The paper presents a design for nitrogen removal in subsurface flow wetlands. The nitrification in the vertical-flow beds (VFBs) is clearly determined by the oxygen balance in the filter. Full nitrification can only be achieved when the oxygen balance is positive. For sizing purposes equations for the calculation of oxygen demand and oxygen input are given. Three possibilities to achieve sufficient soil aeration are presented and explained.
For the denitrification two possibilities are presented. From technical wastewater treatment plants predenitrification is well known. Return rates up to 200% can be used without hydraulic problems for the VFBs. In cases of low C/N ratios an additional application of HFBs has to be used. The design can be carried out using a design of 1 g NO3-N/m2,d achieving a 65% removal in more than 90% of the cases.
The paper discusses some of the equations presented internationally. The suitability of the use of k-values for the processes nitrification and denitrification is especially questioned.