0000000000021751

AUTHOR

J. Ribes

showing 40 related works from this author

Use of biological and sedimentation models for designing Peñíscola WWTP.

2004

This paper presents Peñíscola wastewater treatment plant design. Peñíscola is a tourist city in Castellón (Spain), whose population changes significantly between summer and the rest of the year. The design of the biological and settling treatment units has been confirmed by computer model simulations and provided for biological organic matter, nitrogen and phosphorus removal. Two different treatment schemes have been proposed in order to optimize the plant performance during both seasonal operations. During low-load season, the plant will be operated under extended aeration conditions, so further sludge stabilization will not be needed. During high-load season, the plant will be operated un…

chemistry.chemical_classificationeducation.field_of_studyGeologic SedimentsChemistrySedimentation (water treatment)PopulationWater PollutionEnvironmental engineeringWaterPhosphorusGeneral MedicineModels TheoreticalWaste Disposal FluidWaste treatmentSpainEnvironmental ChemistryAerobic digestionOrganic matterSewage treatmentExtended aerationSeasonsAerationeducationWaste Management and DisposalWater Science and TechnologyEnvironmental technology
researchProduct

Low cost-sensors as a real alternative to on-line nitrogen analysers in continuous systems.

2009

This paper is focused on the evaluation of the applicability of low-cost sensors (pH and ORP) versus nutrient analysers for controlling biological nitrogen removal in WWTPs. A nutrient removal pilot plant located in Carraixet WWTP (Valencia, Spain) that is equipped with a significant number of nutrient analysers and low-cost sensors was used. The relations between reliable, cheap on-line sensors such as pH and ORP (located in anaerobic, anoxic and aerobic zones) and the nitrification/denitrification processes are provided. The nitrification process can be evaluated by measuring the pH difference between the first and last aerobic zones. The denitrification process can be evaluated by measur…

Environmental EngineeringDenitrificationSewageChemistryNitrogenEnvironmental engineeringPilot ProjectsHydrogen-Ion ConcentrationAnoxic watersAerobiosisChemistry Techniques AnalyticalWater PurificationAnaerobic digestionPilot plantWastewaterFuzzy LogicSpainCosts and Cost AnalysisNitrificationSewage treatmentAnaerobiosisAerationWater Science and TechnologyWater science and technology : a journal of the International Association on Water Pollution Research
researchProduct

Resource recovery from sulphate-rich sewage through an innovative anaerobic-based water resource recovery facility (WRRF)

2018

[EN] This research work proposes an innovative water resource recovery facility (WRRF) for the recovery of energy, nutrients and reclaimed water from sewage, which represents a promising approach towards enhanced circular economy scenarios. To this aim, anaerobic technology, microalgae cultivation, and membrane technology were combined in a dedicated platform. The proposed platform produces a high-quality solid- and coliform-free effluent that can be directly discharged to receiving water bodies identified as sensitive areas. Specifically, the content of organic matter, nitrogen and phosphorus in the effluent was 45 mg COD.L-1 , 14.9 mg N.L-1 and 0.5 mg P.L-1 , respectively. Harvested solar…

INGENIERIA HIDRAULICAEnvironmental EngineeringBiosolidsNitrogen0208 environmental biotechnologyBiomassSewage02 engineering and technologyWastewater010501 environmental sciencesWaste Disposal Fluid01 natural sciencesWater PurificationBioreactorsEffluentTECNOLOGIA DEL MEDIO AMBIENTE0105 earth and related environmental sciencesWater Science and TechnologyResource recoveryConservation of Water ResourcesSewageAnaerobic membrane bioreactor (AnMBR)Sulfatesbusiness.industryMembrane photobioreactor (MPBR)Resource recoveryAnaerobic digestion (AD)Pulp and paper industryReclaimed water020801 environmental engineeringWastewaterWater resource recovery facility (WRRF)Water ResourcesEnvironmental sciencebusinessWaste disposalWater Science and Technology
researchProduct

Calibration of denitrifying activity of polyphosphate accumulating organisms in an extended ASM2d model

2010

Abstract This paper presents the results of an experimental study for the modelling and calibration of denitrifying activity of polyphosphate accumulating organisms (PAOs) in full-scale WWTPs that incorporate simultaneous nitrogen and phosphorus removal. The convenience of using different yields under aerobic and anoxic conditions for modelling biological phosphorus removal processes with the ASM2d has been demonstrated. Thus, parameter ηPAO in the model is given a physical meaning and represents the fraction of PAOs that are able to follow the DPAO metabolism. Using stoichiometric relationships, which are based on assumed biochemical pathways, the anoxic yields considered in the extended A…

Environmental EngineeringNitrogenElectronsPilot ProjectsModels BiologicalWaste Disposal FluidDenitrifying bacteriaPolyphosphatesCalibrationProcess optimizationAnaerobiosisWaste Management and DisposalAcetic AcidWater Science and TechnologyCivil and Structural EngineeringAutotrophic ProcessesNitratesBacteriaSewageChemistryEcological ModelingEnvironmental engineeringPhosphorusPollutionAnoxic watersOxygenPolyphosphate-accumulating organismsPilot plantActivated sludgeEnhanced biological phosphorus removalCalibrationBiological systemWater Research
researchProduct

A Semi-Industrial Anmbr Plant for Urban Wastewater Treatment at Ambient Temperature: Analysis of the Filtration Process, Energy Balance and Quantific…

2022

A semi-industrial scale AnMBR urban wastewater treatment plant was operated for 580 days at ambient temperature (ranging from 10-30 ○C) to assess its long-term filtration performance, energy balance and GHG emissions. The applied 20ºC-standardized transmembrane flux (J20) was varied between 15 and 25 LMH and the specific gas demand per m2 of membrane (SGDm) was modified between 0.10 to 0.40 Nm3·m-2·h-1 (corresponding to a specific gas demand per permeate volume (SGDP) between 10 to 20 Nm3·m-3). The filtration strategy allowed successful long-term operations without any chemical cleaning requirements and little fouling for 233 days. The plant operated as a net energy producer for more than 5…

HistoryPolymers and PlasticsEnergia EstalviProcess Chemistry and TechnologyAnaerobiosiChemical Engineering (miscellaneous)Aigües residuals Depuració Tractament biològicBusiness and International ManagementPollutionWaste Management and DisposalIndustrial and Manufacturing EngineeringSSRN Electronic Journal
researchProduct

New frontiers from removal to recycling of nitrogen and phosphorus from wastewater in the Circular Economy

2020

[EN] Nutrient recovery technologies are rapidly expanding due to the need for the appropriate recycling of key elements from waste resources in order to move towards a truly sustainable modern society based on the Circular Economy. Nutrient recycling is a promising strategy for reducing the depletion of non-renewable resources and the environmental impact linked to their extraction and manufacture. However, nutrient recovery technologies are not yet fully mature, as further research is needed to optimize process efficiency and enhance their commercial applicability. This paper reviews state-of-the-art of nutrient recovery, focusing on frontier technological advances and economic and environ…

0106 biological sciencesNutrient cycleEnvironmental EngineeringNitrogenchemistry.chemical_elementBioengineeringWastewater010501 environmental sciencesWaste Disposal Fluid01 natural sciencesNutrient010608 biotechnologyPhotosynthetic-based systemsRecyclingEnvironmental impact assessmentCircular EconomyWaste Management and DisposalTECNOLOGIA DEL MEDIO AMBIENTE0105 earth and related environmental sciencesMembranesWaste managementRenewable Energy Sustainability and the Environment06.- Garantizar la disponibilidad y la gestión sostenible del agua y el saneamiento para todosCircular economyPhosphorusPhosphorusGeneral MedicineIncinerationNutrient recoveryWastewaterchemistryProcess efficiencyEnvironmental scienceCrystallization
researchProduct

Experimental study of the anaerobic urban wastewater treatment in a submerged hollow-fibre membrane bioreactor at pilot scale

2011

The aim of this study was to assess the effect of several operational variables on both biological and separation process performance in a submerged anaerobic membrane bioreactor pilot plant that treats urban wastewater. The pilot plant is equipped with two industrial hollow-fibre ultrafiltration membrane modules (PURON¿ Koch Membrane Systems, 30m 2 of filtration surface each). It was operated under mesophilic conditions (at 33°C), 70days of SRT, and variable HRT ranging from 20 to 6h. The effects of the influent COD/SO 4-S ratio (ranging from 2 to 12) and the MLTS concentration (ranging from 6 to 22gL -1) were also analysed. The main performance results were about 87% of COD removal, efflu…

Hollow-fibre membraneINGENIERIA HIDRAULICABiogasUltrafiltrationEffluentsPilot ProjectsWastewater treatmentWastewaterWaste Disposal FluidIndustrial effluentPerformance assessmentBioreactorsAnaerobiosisWaste Management and DisposalHollow fiber membranePriority journalPilot plantsVolatile fatty acidWaste water managementChemistryChemical oxygen demandUrban wastewaterMethanationMembraneGeneral MedicinePulp and paper industryWaste treatmentHollow fiber reactorWastewaterIndustrial membranesSeparation techniqueMethaneBioconversionEnvironmental EngineeringUltrafiltrationBioreactorBioengineeringArticleWater PurificationBiogasBioreactorMicrofiltrationCitiesEffluentBiological water treatmentTECNOLOGIA DEL MEDIO AMBIENTESubmerged anaerobic membrane bioreactorBiological Oxygen Demand AnalysisMembranesExperimental studyRenewable Energy Sustainability and the EnvironmentEnvironmental engineeringUrban areaMembranes ArtificialBiogas productionNonhumanAnaerobic digestionPilot plantChemical oxygen demandAnoxic conditions
researchProduct

DESASS: A software tool for designing, simulating and optimising WWTPs

2008

This paper presents a very useful software tool to design, simulate and optimise wastewater treatment plants. The program is called DESASS (DEsign and Simulation of Activated Sludge Systems) and has been developed by CALAGUA research group. The mathematical model implemented is the Biological Nutrient Removal Model No.1 (BNRM1) which allows simulating the most important physical, chemical and biological processes taking place in treatment plants. DESASS calculates the performance under steady or transient state of whole treatment schemes including primary settlers, volatile fatty acid generation systems by primary sludge fermentation, activated sludge systems for biological organic matter a…

chemistry.chemical_classificationTransient stateEnvironmental EngineeringDenitrificationPrimary (chemistry)Waste managementEcological Modelingfood and beveragesNutrientActivated sludgechemistryWastewaterEnvironmental scienceOrganic matterSewage treatmentSoftwareEnvironmental Modelling & Software
researchProduct

Performance of industrial scale hollow-fibre membranes in a submerged anaerobic MBR (HF-SAnMBR) system at mesophilic and psychrophilic conditions

2013

The aim of this work was to evaluate the effect of temperature on the performance of industrial hollow-fibre (HF) membranes treating urban wastewater in a submerged anaerobic MBR system (SAnMBR). To this end, a demonstration plant with two commercial HF ultrafiltration membrane modules (PURON®, Koch Membrane Systems, PUR-PSH31) was operated at 20, 25 and 33 °C. The mixed liquor total solid (MLTS) level was a key factor affecting membrane permeability (K). K was higher under psychrophilic than mesophilic conditions when operating at similar transmembrane fluxes and MLTS, because the biomass activity of the psychrophilic mixed liquor was lower than the mesophilic mixed liquor. Thus, lower ext…

Mesophilic and psychrophilic anaerobic conditionsSoluble microbial products (SMPs)INGENIERIA HIDRAULICAMembrane permeabilityFoulingChemistryEnvironmental engineeringUltrafiltrationFiltration and SeparationPulp and paper industryAnalytical ChemistryMembraneExtracellular polymeric substanceMembrane permeabilityWastewaterExtracellular polymeric substances (EPSs)PsychrophileIndustrial hollow-fibre membranesTECNOLOGIA DEL MEDIO AMBIENTEMesophile
researchProduct

Reliable method for assessing the COD mass balance of a submerged anaerobic membrane bioreactor (SAMBR) treating sulphate-rich municipal wastewater

2012

The anaerobic treatment of sulphate-rich wastewater causes sulphate reducing bacteria (SRB) and methanogenic archaea (MA) to compete for the available substrate. The outcome is lower methane yield coefficient and, therefore, a reduction in the energy recovery potential of the anaerobic treatment. Moreover, in order to assess the overall chemical oxygen demand (COD) balance, it is necessary to determine how much dissolved CH4 is lost in the effluent. The aim of this study is to develop a detailed and reliable method for assessing the COD mass balance and, thereby, to establish a more precise methane yield coefficient for anaerobic systems treating sulphate-rich wastewaters. A submerged anaer…

Environmental EngineeringPilot ProjectsWaste Disposal FluidWater PurificationBioreactorsBiogasBioreactorAnaerobiosisCitiesSulfate-reducing bacteriaEffluentIn Situ Hybridization FluorescenceWater Science and TechnologyBiological Oxygen Demand AnalysisBacteriaSewageSulfatesChemistryChemical oxygen demandEnvironmental engineeringReproducibility of ResultsMembranes ArtificialPulp and paper industryAnaerobic digestionWaste treatmentWastewaterSpainBiofuelsMethaneOxidation-ReductionWater Science and Technology
researchProduct

Application of the General Model "Biological Nutrient Removal Model No.1" to upgrade two full-scale WWTPs

2012

In this paper, two practical case studies for upgrading two wastewater treatment plants (WWTPs) using the general model BNRM1 (Biological Nutrient Removal Model No. 1) are presented. In the first case study, the Tarragona WWTP was upgraded by reducing the phosphorus load to the anaerobic digester in order to minimize the precipitation problems. Phosphorus load reduction was accomplished by mixing the primary sludge and the secondary sludge and by elutriating the mixed sludge. In the second case study, the Alcantarilla WWTP, the nutrient removal was enhanced by maintaining a relatively low dissolved oxygen concentration in Stage A to maintain the acidogenic bacteria activity. The VFA produce…

AcidogenesisBiological nutrient removalWATER TREATMENT PLANTSAerobic bacteriachemistry.chemical_elementActivated sludge modelPhosphatesWater PurificationWASTE-WATERBNRM1Environmental ChemistryAnaerobiosisOrganic ChemicalsWaste Management and DisposalTECNOLOGIA DEL MEDIO AMBIENTEWater Science and TechnologyCALIBRATIONSewagePhosphorusEnvironmental engineeringGeneral MedicineModels TheoreticalASM2DAerobiosisACTIVATED-SLUDGE MODELActivated sludge modelsEnhanced biological phosphorus removalWastewaterchemistrySIMULATIONPlant-wide mathematical modellingEnvironmental scienceSewage treatmentWater treatmentSanitary EngineeringWWTP upgrading
researchProduct

Influence of total solids concentration on membrane permeability in a submerged hollow-fibre anaerobic membrane bioreactor.

2012

The main aim of this work was to study the influence of the mixed liquor total solids (MLTS) concentration on membrane permeability (K 20) in a submerged anaerobic membrane bioreactor (SAnMBR) pilot plant, which is equipped with industrial hollow-fibre membranes and treats urban wastewater. This pilot plant was operated at 33°C and 70 days of SRT. Two different transmembrane fluxes (13.3 and 10 LMH) were tested with a gas sparging intensity of 0.23 Nm 3 m -2 h -1 (measured as Specific Gas Demand referred to membrane area). A linear dependence of K 20 on MLTS concentration was observed within a range of MLTS concentration from 13 to 32 g L -1 and J 20 of 10 LMH. K 20 was maintained at sustai…

Submerged anaerobic membrane bioreactorINGENIERIA HIDRAULICAEnvironmental EngineeringChromatographyMembrane permeabilityChemistryFouling rateAnaerobic membrane bioreactorMembranes ArtificialTotal dissolved solidsWaste Disposal FluidPermeabilityMembranePilot plantBioreactorsWastewaterPermeability (electromagnetism)Industrial membranesAnaerobiosisSpargingTECNOLOGIA DEL MEDIO AMBIENTEWater Science and TechnologyMixed liquor total solids concentrationWater science and technology : a journal of the International Association on Water Pollution Research
researchProduct

A methodology for sequencing batch reactor identification with artificial neural networks: A case study

2009

This paper presents a systematic methodology based on the application of artificial neural networks for sequencing batch reactor (SBR) identification. The SBR is a fill-and-draw biological wastewater technology, which is specially suited for nutrient removal. The proposed approach makes optimal use of the available data during the training stage and it is aimed at achieving high generalization ability. For this purpose, a wide range of experimental conditions, including different solids retention times and influent characteristics, has been used. The methodology is successfully applied to develop a soft-sensor for monitoring a laboratory-scale SBR operated for enhanced biological phosphorus…

EngineeringArtificial neural networkbusiness.industryGeneral Chemical EngineeringLagEnvironmental engineeringQuality controlSequencing batch reactorSoft sensorComputer Science ApplicationsIdentification (information)Enhanced biological phosphorus removalRange (statistics)Process engineeringbusinessComputers & Chemical Engineering
researchProduct

Mathematical modelling of filtration in submerged anaerobic MBRs (SAnMBRs): long-term validation

2013

The aim of this study was the long-term validation of a model capable of reproducing the filtration process occurring in a submerged anaerobic membrane bioreactor (SAnMBR) system. The proposed model was validated using data obtained horn a SAnMBR demonstration plant fitted with industrial-scale hollow-fibre membranes. The validation was carried out using both lightly and heavily fouled membranes operating at different bulk concentrations, gas sparging intensities and transmembrane fluxes. Across a broad spectrum of operating conditions, the model correctly forecast the respective experimental data in the long term. The simulation results revealed the importance of controlling irreversible f…

EngineeringINGENIERIA HIDRAULICAFiltration and SeparationAnaerobic membrane bioreactorBiochemistryIndustrial-scale hollow fibre moduleslaw.inventionlawSubmergedGeneral Materials SciencePhysical and Theoretical ChemistrySpargingFiltrationTECNOLOGIA DEL MEDIO AMBIENTELong-term validationFiltration modelFoulingbusiness.industryEnvironmental engineeringTerm (time)MembraneResistance in seriesScientific methodbusinessAnaerobic exercise
researchProduct

Application of the Morris method for screening the influential parameters of fuzzy controllers applied to wastewater treatment plants

2011

In this paper,we evaluate the application of a sensitivity analysis to help fine-tuning a fuzzy controller for a biological nitrogen and phosphorus removal (BNPR) plant. TheMorris Screeningmethod is proposed and evaluated as a prior step to obtain the parameter significance ranking. First, an iterative procedure has been performed in order to find out the proper repetition number of the elementary effects (r) of the method. The optimal repetition number found in this study (r = 60) is in direct contrast to previous applications of the Morris method, which usually use low repetition number, e.g. r = 10 ~ 20. Working with a non-proper repetition number (r) could lead to Type I error (identify…

EngineeringParameterFuzzy controllersWastewater treatmentWastewaterScreening methodChemicals removal (water treatment)Parameter significance rankingWaste ManagementWastewater treatment plantsStatisticsWater treatmentFalse positiveControl systemWater Science and TechnologyControllersPhosphorusMorris methodFine-tuningError analysisPollutant removalFuzzy mathematicsCalibrationFalse negativesScreeningSensitivity analysisType I and type II errorsOptimizationWastewater treatment plant (WWTP)Environmental EngineeringWaste water treatment plantNitrogenIterative proceduresNumerical methodRepetition NumberFuzzy logicSewage pumping plantsArticleFalse positive resultFuzzy LogicControl theoryMorris methodSensitivity (control systems)Water treatment plantsBiological water treatmentFalse negative resultTECNOLOGIA DEL MEDIO AMBIENTEBiological nitrogen and phosphorus removalType II errorToxicitybusiness.industryNitrogen removalFuzzy mathematicsRankingFuzzy controllerType-I errorbusiness
researchProduct

DSC: software tool for simulation-based design of control strategies applied to wastewater treatment plants.

2011

This paper presents a computer tool called DSC (Simulation based Controllers Design) that enables an easy design of control systems and strategies applied to wastewater treatment plants. Although the control systems are developed and evaluated by simulation, this tool aims to facilitate the direct implementation of the designed control system to the PC of the full-scale WWTP (wastewater treatment plants). The designed control system can be programmed in a dedicated control application and can be connected to either the simulation software or the SCADA of the plant. To this end, the developed DSC incorporates an OPC server (OLE for process control) which facilitates an open-standard communic…

EngineeringCommunication protocolComputer controlProcess designIndustrial process applicationsWastewater treatmentWastewaterImplementation processcomputer.software_genreWaste Disposal FluidWWTPsAeration controlPerformance assessmentSoftwareControl theoryReclamationWastewater treatment plantsRatingAerationSimulation-based designsWater treatmentComputer softwareProcess engineeringControl systemDesign of control systemWater Science and TechnologyComputer control systemsCommunication protocolsComputer programControl strategiesCommunicationSimulation softwareOPC serverComputer simulationSimulation softwarePollutant removalFull-scale plantsWastewater treatment plant (WWTP)Environmental EngineeringDesignWaste water treatment plantControl performanceEquipmentSoftware toolComputer programMicrocomputerControl applicationsFull-scale applicationsNutrient cyclingSewage pumping plantsArticleNumerical modelSCADAControl theoryOle for process controlsControlProcess controlSimulation-basedComputer SimulationWater treatment plantsTECNOLOGIA DEL MEDIO AMBIENTESensorbusiness.industryControllers designSystems performanceControl engineeringControl parametersOPC communicationPotential capabilityControl systemProcess controlProcess designbusinesscomputerComputer toolsSoftwareNutrientWater science and technology : a journal of the International Association on Water Pollution Research
researchProduct

Modelling anaerobic biomass growth kinetics with a substrate threshold concentration.

2004

Abstract Many bacteria have been observed to stop growing below a certain substrate threshold concentration. In this study, a modification of the Monod kinetics expression has been proposed to take into account this substrate threshold concentration observed in bacterial growth. Besides the threshold concentration no additional parameters have been added to the kinetic expression and so, only the substrate threshold concentration and the half-saturation constant have to be estimated for model calibration purposes. Furthermore, for parameter estimation purposes, practical identifiability of this new function has been studied and the results have been satisfactory. The new model has been appl…

Periodicitywaste-waterHydrogenBacterial growthbatchactivated sludgeBiomassSulfate-reducing bacteriaWaste Management and DisposalWater Science and TechnologyafvalwaterbehandelingEcological ModelingPollutionSystems and Control Groupregel- en systeemtechniekCalibrationMilieutechnologieBiological systemLimiting factorEnvironmental EngineeringbiomassakineticaKineticschemistry.chemical_elementBiologysubstratenmodelsBioreactoractivated-sludgesubstratesmodellenmethanolCivil and Structural EngineeringWIMEKbiomassBacteriageactiveerd slibEnvironmental engineeringSubstrate (chemistry)Leerstoelgroep Meet- regel- en systeemtechniekModels TheoreticalKineticswaste water treatmentchemistrykineticsEnvironmental TechnologyIdentifiabilitycontinuous-cultureLeerstoelgroep Meet-HydrogenWater research
researchProduct

An advanced control strategy for biological nutrient removal in continuous systems based on pH and ORP sensors

2012

[EN] A fuzzy logic-based control system that uses low-cost sensors for controlling and optimizing the biological nitrogen removal in continuous systems has been developed. The novelty of this control system is the use of several pH, ORP, and dissolved oxygen (DO) sensors instead of on-line nitrogen sensors/analyzers. The nitrogen control system was developed and implemented in a UCT pilot plant fed with wastewater from a full-scale plant. The developed nitrification controller allows the effluent ammonium concentration to be maintained below the effluent criteria discharge with the minimum energy consumption. The denitrification process controller allows the energy consumption derived from …

DenitrificationChemistryGeneral Chemical EngineeringEnvironmental engineeringGeneral ChemistryEnergy consumptionNitrificationIndustrial and Manufacturing EngineeringFuzzy logicPilot plantWastewaterControl theoryControl systemControlDenitrificationEnvironmental ChemistryNitrificationBiological nitrogen removalLow-cost sensorsEffluentTECNOLOGIA DEL MEDIO AMBIENTE
researchProduct

Factors that affect the permeability of commercial hollow-fibre membranes in a submerged anaerobic MBR (HF-SAnMBR) system

2013

A demonstration plant with two commercial HF ultrafiltration membrane modules (PURON (R), Koch Membrane Systems, PUR-PSH31) was operated with urban wastewater. The effect of the main operating variables on membrane performance at sub-critical and supracritical filtration conditions was tested. The physical operating variables that affected membrane performance most were gas sparging intensity and back-flush (BF) frequency. Indeed, low gas sparging intensities (around 0.23 Nm(3) h(-1) m(-2)) and low BF frequencies (30s back-flush for every 10 basic filtration relaxation cycles) were enough to enable membranes to be operated sub-critically even when levels of mixed liquor total solids were hi…

INGENIERIA HIDRAULICAEnvironmental EngineeringMembrane permeabilityAnalytical chemistryUltrafiltrationBack-flush frequencyPermeabilityBioreactorsHollow-fibre membranesBioreactorAnaerobiosisBiogas spargingWaste Management and DisposalSpargingTECNOLOGIA DEL MEDIO AMBIENTEWater Science and TechnologyCivil and Structural EngineeringSubmerged anaerobic membrane bioreactorChromatographyFoulingChemistryEcological ModelingCommercialMembranes ArtificialPollutionAnaerobic digestionMembraneMembrane permeabilityWastewaterPermeability (electromagnetism)
researchProduct

Design methodology for submerged anaerobic membrane bioreactors (AnMBR): A case study

2015

[EN] The main objective of this study is to propose guidelines for designing submerged anaerobic MBR (AnMBR) technology for municipal wastewater treatment. The design methodology was devised on the basis of simulation and experimental results from an AnMBR plant featuring industrial-scale hollow-fibre membranes. The proposed methodology aims to minimise both capital expenditure and operating expenses, and the key parameters considered were: hydraulic retention time, solids retention time, mixed liquor suspended solids concentration in the membrane tank, 20 C-standardised critical flux, specificgas demand per square metre of membrane area, and flow of sludge being recycled from the membrane …

CAPEX/OPEXINGENIERIA HIDRAULICAEngineeringIndustrial-scale hollow-fibre membranesWaste managementHydraulic retention timebusiness.industrySubmerged anaerobic MBR (AnMBR)Environmental engineeringFiltration and SeparationAnalytical ChemistrySquare meterMixed liquor suspended solidsMembraneWastewaterMunicipal wastewater treatmentDesign methodologyBioreactorAnaerobic reactorbusinessAnaerobic exerciseTECNOLOGIA DEL MEDIO AMBIENTESeparation and Purification Technology
researchProduct

An improved sampling strategy based on trajectory design for application of the Morris method to systems with many input factors

2012

[EN] In this paper, a revised version of the Morris approach, which includes an improved sampling strategy based on trajectory design, has been adapted to the screening of the most influential parameters of a fuzzy controller applied to WWTPs. Due to the high number of parameters, a systematic approach has been proposed to apply this improved sampling strategy with low computational demand. In order to find out the proper repetition number of elementary effects of each input factor on model output (EEi) calculations, an iterative and automatic procedure has been applied. The results show that the sampling strategy has a significant effect on the parameter significance ranking and that rando…

Mathematical optimizationEnvironmental EngineeringComputer scienceEcological ModelingFuzzy controllersSampling (statistics)Parameter spaceRepetition NumberFuzzy logicSampling strategyRankingControl theoryTrajectoryMorris methodMorris screeningSensitivity analysisSoftwareTECNOLOGIA DEL MEDIO AMBIENTE
researchProduct

Electrical conductivity as a state indicator for the start-up period of anaerobic fixed-bed reactors.

2016

The aim of this work was to analyse the applicability of electrical conductivity sensors for on-line monitoring the start-up period of an anaerobic fixed-bed reactor. The evolution of bicarbonate concentration and methane production rate was analysed. Strong linear relationships between electrical conductivity and both bicarbonate concentration and methane production rate were observed. On-line estimations of the studied parameters were carried out in a new start-up period by applying simple linear regression models, which resulted in a good concordance between both observed and predicted values. Electrical conductivity sensors were therefore identified as an interesting method for monitori…

Work (thermodynamics)start-upEnvironmental EngineeringPeriod (periodic table)[SDV]Life Sciences [q-bio]BicarbonateNuclear engineering0208 environmental biotechnologyAnalytical chemistry02 engineering and technology010501 environmental sciencesbioréacteur à lit fixe7. Clean energy01 natural scienceson line measurementchemistry.chemical_compoundBacteria AnaerobicReliability (semiconductor)BioreactorsElectrical resistivity and conductivityconductivité électriqueBioreactorelectroconductivityAnaerobiosis0105 earth and related environmental sciencesWater Science and TechnologyElectric ConductivityReproducibility of ResultsStart up020801 environmental engineeringchemistrydémarragecapteurAnaerobic exerciseWater Pollutants Chemicalmesure en ligneWater science and technology : a journal of the International Association on Water Pollution Research
researchProduct

Global sensitivity analysis of a filtration model for submerged anaerobic membrane bioreactors (AnMBR)

2014

The results of a global sensitivity analysis of a filtration model for submerged anaerobic MBRs (AnMBRs) are assessed in this paper. This study aimed to (1) identify the less- (or non-) influential factors of the model in order to facilitate model calibration and (2) validate the modelling approach (i.e. to determine the need for each of the proposed factors to be included in the model). The sensitivity analysis was conducted using a revised version of the Morris screening method. The dynamic simulations were conducted using long-term data obtained from an AnMBR plant fitted with industrial-scale hollow-fibre membranes. Of the 14 factors in the model, six were identified as influential, i.e…

EngineeringINGENIERIA HIDRAULICAEnvironmental EngineeringCalibration (statistics)Bioengineeringlaw.inventionBioreactorsGlobal sensitivity analysislawBioreactorSensitivity (control systems)AnaerobiosisWaste Management and DisposalFiltrationTECNOLOGIA DEL MEDIO AMBIENTEFiltration modelRenewable Energy Sustainability and the Environmentbusiness.industryEnvironmental engineeringMembranes ArtificialGeneral MedicineModels TheoreticalMembraneGlobal sensitivity analysisCalibrationMorris screeningBiochemical engineeringbusinessAnaerobic exerciseSubmerged anaerobic membrane bioreactorsFiltration
researchProduct

Optimum design and operation of primary sludge fermentation schemes for volatile fatty acids production.

2003

This paper presents a model-knowledge based algorithm for optimising the primary sludge fermentation process design and operation. This is a recently used method to obtain the volatile fatty acids (VFA), needed to improve biological nutrient removal processes, directly from the raw wastewater. The proposed algorithm consists in a heuristic reasoning algorithm based on the expert knowledge of the process. Only effluent VFA and the sludge blanket height (SBH) have to be set as design criteria, and the optimisation algorithm obtains the minimum return sludge and waste sludge flow rates which fulfil those design criteria. A pilot plant fed with municipal raw wastewater was operated in order to …

Optimal designEngineeringEnvironmental EngineeringWaste managementSewagebusiness.industryEcological ModelingProcess designFatty Acids VolatilePollutionWaste Disposal FluidAnaerobic digestionPilot plantWastewaterFacility Design and ConstructionFermentationProduction (economics)FermentationbusinessProcess engineeringWaste Management and DisposalEffluentAlgorithmsWater Science and TechnologyCivil and Structural EngineeringWater research
researchProduct

Fermentation and elutriation of primary sludge: Effect of SRT on process performance

2007

Abstract A primary sludge fermentation–elutriation pilot plant was operated using in-line and side-stream schemes. The influence of solids retention time, recirculation sludge flow-rate and solids concentration on the fermentation–elutriation process performance has been assessed in this paper. The use of high elutriation flows (12% of influent flow) improved the volatile fatty acids (VFA) concentration in the effluent stream. Suspended solids removal efficiency decreased in the primary settler when the solids retention time (SRT) was increased from 4 to 8 days. Disintegration step during hydrolysis process was pointed out as the main reason for that decrease. Maximum VFA productions were a…

Time FactorsEnvironmental EngineeringNitrogenPilot ProjectsElutriationHydrolysisBioreactorsVolatile organic compoundWaste Management and DisposalEffluentWater Science and TechnologyCivil and Structural Engineeringchemistry.chemical_classificationSuspended solidsChromatographySewageHydrolysisEcological ModelingPhosphorusHydrogen-Ion ConcentrationFatty Acids VolatileTotal dissolved solidsPollutionPilot plantchemistryFermentationFermentationAigües residuals Plantes de tractament
researchProduct

Advanced control system for optimal filtration in submerged anaerobic MBRs (SAnMBRs)

2013

The main aim of this study was to develop an advanced controller to optimise filtration in submerged anaerobic MBRs (SAnMBRs). The proposed controller was developed, calibrated and validated in a SAnMBR demonstration plant fitted with industrial-scale hollow-fibre membranes with variable influent flow and load. This 2-layer control system is designed for membranes operating sub-critically and features a lower layer (on/off and PID controllers) and an upper layer (knowledge-based controller). The upper layer consists of a MIMO (multiple-input-multiple-output) control structure that regulates the gas sparging for membrane scouring and the frequency of physical cleaning (ventilation and back f…

INGENIERIA HIDRAULICAIndustrial-scale hollow-fibre membranesFoulingKnowledge-based controllerEnvironmental engineeringPID controllerFiltration and SeparationEnergy savingsBiochemistrylaw.inventionAdvanced control systemMembraneControl theorylawControl systemSubmerged anaerobic MBRVentilation (architecture)Environmental scienceGeneral Materials SciencePhysical and Theoretical ChemistrySpargingFiltrationTECNOLOGIA DEL MEDIO AMBIENTE
researchProduct

Anaerobic membrane bioreactors (AnMBR) treating urban wastewater in mild climates

2020

[EN] Feasibility of an AnMBR demonstration plant treating urban wastewater (UWW) at temperatures around 25-30 degrees C was assessed during a 350-day experimental period. The plant was fed with the effluent from the pretreatment of a full-scale municipal WWTP, characterized by high COD and sulfate concentrations. Biodegradability of the UWW reached values up to 87%, although a portion of the biodegradable COD was consumed by sulfate reducing organisms. Effluent COD remained below effluent discharge limits, achieving COD removals above 90%. System operation resulted in a reduction of sludge production of 36-58% compared to theoretical aerobic sludge productions. The membranes were operated a…

0106 biological sciencesEnvironmental EngineeringBioengineeringMild/warmer climateWastewater010501 environmental sciencesWaste Disposal Fluid01 natural scienceschemistry.chemical_compoundBioreactors010608 biotechnologyBioreactorUrban wastewater (UWW)AnaerobiosisSulfateWaste Management and DisposalEffluentTECNOLOGIA DEL MEDIO AMBIENTE0105 earth and related environmental sciencesRenewable Energy Sustainability and the EnvironmentAnaerobic membrane bioreactor (AnMBR)Membrane foulingMembranes ArtificialGeneral MedicineBiodegradationPulp and paper industryMethane productionIndustrial-scale membraneMembraneWastewaterchemistryEnvironmental scienceMethaneAnaerobic exerciseDemonstration plant
researchProduct

A supervisory control system for optimising nitrogen removal and aeration energy consumption in wastewater treatment plants

2002

A fuzzy logic supervisory control system for optimising nitrogen removal and aeration energy consumption has been developed. This control system allows optimising and controlling the dissolved oxygen (DO) concentration in the aerobic reactors, the blowers discharge pressure and the effluent ammonia and nitrate concentrations. DO is controlled by adjusting control valve opening and blower discharge pressure is controlled by modifying rotational speed of the blowers. Optimum nitrification/denitrification is achieved by modifying the DO set point in the last aerobic reactor and the internal recirculation. This system has been tested by simulation in a Bardenpho process using the Activated Slud…

Environmental EngineeringDenitrificationActivated sludgeEnvironmental engineeringEnvironmental scienceProcess controlNitrificationSewage treatmentActivated sludge modelAerationDischarge pressureWater Science and TechnologyWater Science and Technology
researchProduct

Biological Nutrient Removal Model No. 2 (BNRM2): a general model for wastewater treatment plants

2013

This paper presents the plant-wide model Biological Nutrient Removal Model No. 2 (BNRM2). Since nitrite was not considered in the BNRM1, and this previous model also failed to accurately simulate the anaerobic digestion because precipitation processes were not considered, an extension of BNRM1 has been developed. This extension comprises all the components and processes required to simulate nitrogen removal via nitrite and the formation of the solids most likely to precipitate in anaerobic digesters. The solids considered in BNRM2 are: struvite, amorphous calcium phosphate, hidroxyapatite, newberite, vivianite, strengite, variscite, and calcium carbonate. With regard to nitrogen removal via…

Simulación y diseño de estaciones de tratamiento de aguas residuales 32484 / W - Programa de doctorado en ingeniería del agua y medioambiental 2077Simulación y diseño de estaciones de tratamiento de aguas residuales 32484 / X - Máster universitario en ingeniería hidráulica y medio ambiente 2152Environmental EngineeringNitritePrecipitationWater PurificationStrengitechemistry.chemical_compoundBioreactorsBNRM1BioreactorChemical PrecipitationSimulación y diseño de estaciones de tratamiento de aguas residuales 32484 / W - Programa de doctorado en ingeniería del agua y medioambiental 2218Computer SimulationAmmoniumNitriteTECNOLOGIA DEL MEDIO AMBIENTENitritesWater Science and TechnologyChemistryEnvironmental engineeringModels TheoreticalPulp and paper industryActivated sludge modelsKineticsAnaerobic digestionActivated sludgeStruvitePlant-wide mathematical modellingSewage treatmentWater Science and Technology
researchProduct

A filtration model applied to submerged anaerobic MBRs (SAnMBRs)

2013

The aim of this study was to develop a model able to correctly reproduce the filtration process of submerged anaerobic MBRs (SAnMBRs). The proposed model was calibrated and validated in a SAnMBR demonstration plant fitted with industrial-scale hollow-fibre membranes. Three suspended components were contemplated in the model: total solids concentration; dry mass of cake on the membrane surface; and dry mass of irreversible fouling on the membrane surface. The model addressed the following physical processes: the build-up and compression of the cake layer during filtration; cake layer removal using biogas sparging to scour the membrane; cake layer removal during back-flushing; and the consoli…

INGENIERIA HIDRAULICAIndustrial-scale hollow-fibre membranesFiltration modelFoulingChemistryEnvironmental engineeringFiltration and SeparationTotal dissolved solidsPulp and paper industryBiochemistryResistance-in-series-basedMembraneBiogasSubmerged anaerobic MBRGeneral Materials ScienceLayer removalPhysical and Theoretical ChemistryMembrane surfaceAnaerobic exerciseSpargingTECNOLOGIA DEL MEDIO AMBIENTE
researchProduct

Modelling of an activated primary settling tank including the fermentation process and VFA elutriation

2002

A complete model of a primary settler including both sedimentation and biological processes is presented. It is a one-dimensional model based on the solids flux concept and the conservation of mass that uses the Takács model for the settling velocity, which is corrected by a compression function in the lower layers. The biological model is based on the ASM2 and enlarged with the fermentation model proposed by this research group. The settler was split in ten layers and the flux terms in the mass balance for each layer is obtained by means of the settling model. A pilot plant has been operated to study the primary sludge fermentation and volatile fatty acids (VFA) elutriation in a primary se…

Primary (chemistry)ChemistrySedimentation (water treatment)Environmental engineeringSedimentacióPhosphorusGeneral MedicineElutriationModels TheoreticalFatty Acids VolatileWaste Disposal FluidPilot plantBiodegradation EnvironmentalSettlingWastewaterFermentationEnvironmental ChemistryFermentationAigües residuals Plantes de tractamentWaste Management and DisposalConservation of massWater Science and Technology
researchProduct

Modeling the anaerobic treatment of sulfate rich urban wastewater. Application to AnMBR technology

2020

[EN] Although anaerobic membrane bioreactors (AnMBR) are a core technology in the transition of urban wastewater (UWW) treatment towards a circular economy, the transition is being held back by a number of bottlenecks. The dissolved methane released from the effluent, the need to remove nutrients (ideally by recovery), or the energy lost by the competition between methanogenic and sulfate-reducing bacteria (SRB) for the biodegradable COD have been identified as the main issues to be addressed before AnMBR becomes widespread. Mathematical modeling of this technology can be used to obtain further insights into these bottlenecks plus other valuable information for design, simulation and contro…

AcidogenesisAnaerobic membrane bioreactorEnvironmental EngineeringMethanogenesis0208 environmental biotechnology02 engineering and technology010501 environmental sciencesWastewater01 natural sciencesWaste Disposal FluidBioreactorsBNRM2BioreactorAnaerobiosisWaste Management and DisposalEffluentTECNOLOGIA DEL MEDIO AMBIENTE0105 earth and related environmental sciencesWater Science and TechnologyCivil and Structural EngineeringSulfate-rich urban wastewaterSulfatesEcological ModelingModelingPulp and paper industryPollution020801 environmental engineeringAnaerobic digestionPilot plantWastewaterAcetogenesisEnvironmental scienceMethane
researchProduct

Model-based automatic tuning of a filtration control system for submerged anaerobic membrane bioreactors (AnMBR)

2014

This paper describes a model-based method to optimise filtration in submerged AnMBRs. The method is applied to an advanced knowledge-based control system and considers three statistical methods: (1) sensitivity analysis (Morris screening method) to identify an input subset for the advanced controller; (2) Monte Carlo method (trajectory-based random sampling) to find suitable initial values for the control inputs; and (3) optimisation algorithm (performing as a supervisory controller) to re-calibrate these control inputs in order to minimise plant operating costs. The model-based supervisory controller proposed allowed filtration to be optimised with low computational demands (about 5min). E…

INGENIERIA HIDRAULICAEngineeringMonte Carlo methodFiltration and SeparationBiochemistrylaw.inventionControl theorylawGeneral Materials ScienceSensitivity (control systems)Physical and Theoretical ChemistryControl systemProcess engineeringTECNOLOGIA DEL MEDIO AMBIENTESpargingFiltrationOperating costDowntimebusiness.industryModel-based automatic tuningControl engineeringControl systembusinessSubmerged anaerobic membrane bioreactorsModel filtrationJournal of Membrane Science
researchProduct

Designing an AnMBR-based WWTP for energy recovery from urban wastewater: The role of primary settling and anaerobic digestion

2015

The main objective of this paper is to assess different treatment schemes for designing a submerged anaerobic membrane bioreactor (AnMBR) based WWTP. The economic impact of including a primary settling (PS) stage and further anaerobic digestion (AD) of the wasted sludge has been evaluated. The following operating scenarios were considered: sulphate-rich and low-sulphate urban wastewater (UWW) treatment at 15 and 30 ºC. To this aim, the optimum combination of design/operating parameters that resulted in minimum total cost (CAPEX plus OPEX) for the different schemes and scenarios was determined. The AnMBR design was based on both simulation and experimental results from an AnMBR plant featuri…

Energy recoveryEngineeringCAPEX/OPEXINGENIERIA HIDRAULICAIndustrial-scale hollow-fibre membranesbusiness.industryFull-scale designEnvironmental engineeringSubmerged anaerobic MBR (AnMBR)Filtration and SeparationAnaerobic membrane bioreactorAnalytical ChemistryAnaerobic digestionWastewaterSettlingUrban wastewater treatmentbusinessTECNOLOGIA DEL MEDIO AMBIENTE
researchProduct

Parameter subset selection for the dynamic calibration of activated sludge models (ASMs): experience versus systems analysis.

2007

In this work we address the issue of parameter subset selection within the scope of activated sludge model calibration. To this end, we evaluate two approaches: (i) systems analysis and (ii) experience-based approach. The evaluation has been carried out using a dynamic model (ASM2d) calibrated to describe nitrogen and phosphorus removal in the Haaren WWTP (The Netherlands). The parameter significance ranking shows that the temperature correction coefficients are among the most influential parameters on the model output. This outcome confronts the previous identifiability studies and the experience based approaches which excluded them from their analysis. Systems analysis reveals that parame…

EngineeringEnvironmental EngineeringSystems AnalysisSelection (relational algebra)Sewagebusiness.industryCalibration (statistics)Contrast (statistics)CollinearityActivated sludge modelModels Theoreticalcomputer.software_genreWaste Disposal FluidWater PurificationSystems analysisBioreactorsRankingCalibrationIdentifiabilityData miningbusinesscomputerWater Science and TechnologyWater science and technology : a journal of the International Association on Water Pollution Research
researchProduct

Biological nutrient removal model No.1 (BNRM1)

2004

This paper presents the results of the work carried out by the CALAGUA Group on Mathematical Modelling of Biological Treatment Processes: the Biological Nutrient Removal Model No.1. This model is based on a new concept for dynamic simulation of wastewater treatment plants: a unique model can be used to design, simulate and optimize the whole plant, as it includes most of the biological and physico-chemical processes taking place in all treatment operations. The physical processes included are: settling and clarification processes (flocculated settling, hindered settling and thickening), volatile fatty acids elutriation and gasÐliquid transfer. The chemical interactions included comprise aci…

chemistry.chemical_classificationAcidogenesisEnvironmental EngineeringMethanogenesisEnvironmental engineeringBiologyAnoxic watersWastewaterSettlingchemistryAcetogenesisSewage treatmentOrganic matterBiochemical engineeringWater Science and TechnologyWater Science and Technology
researchProduct

Sub-critical long-term operation of industrial scale hollow-fibre membranes in a submerged anaerobic MBR (HF-SAnMBR) system

2012

The aim of this study was to evaluate the long-term performance of hollow-fibre (HF) membranes used to treat urban wastewater in a submerged anaerobic MBR when operating sub-critically. To this end, a demonstration plant with two industrial scale HF ultrafiltration membrane modules was operated under different conditions. The main factor affecting membrane performance was the concentration of mixed liquor total solids (MLTS). The reversible fouling rate remained low even when MLTS levels (about 25 g L−1) in the membrane tank were high. No chemical cleaning was conducted whilst operating the plant for more than one year because no irreversible fouling problems were detected. The almost compl…

Industrial scale hollow-fibre membranesINGENIERIA HIDRAULICAFoulingChemistryMembrane foulingEnvironmental engineeringUltrafiltrationFiltering resistanceFiltration and SeparationAnalytical Chemistrylaw.inventionLong-term operationMembraneWastewaterBiogaslawSubmerged anaerobic MBRSub-critical filtrationTECNOLOGIA DEL MEDIO AMBIENTESpargingFiltrationSeparation and Purification Technology
researchProduct

Instrumentation, control, and automation for submerged anaerobic membrane bioreactors

2015

A submerged anaerobic membrane bioreactor (AnMBR) demonstration plant with two commercial hollow-fibre ultrafiltration systems (PURON® , Koch Membrane Systems, PUR-PSH31) was designed and operated for urban wastewater treatment. An instrumentation, control, and automation (ICA) system was designed and implemented for proper process performance. Several single-input-single-output (SISO) feedback control loops based on conventional on off and PID algorithms were implemented to control the following operating variables: flow-rates (influent, permeate, sludge recycling and wasting, and recycled biogas through both reactor and membrane tanks), sludge wasting volume, temperature, transmembrane pr…

EngineeringINGENIERIA HIDRAULICAAutomatic controlUltrafiltrationPID controllerUltrafiltrationIndustrial-scale membranesFeedbackWater PurificationBacteria AnaerobicBioreactorsBiogasBioreactorEnvironmental ChemistryAnaerobiosisSubmerged anaerobic membrane bioreactor (AnMBR)Waste Management and DisposalInstrumentationSpargingTECNOLOGIA DEL MEDIO AMBIENTEWater Science and TechnologyWaste managementSewagebusiness.industryMembranes ArtificialGeneral MedicineEquipment DesignRoboticsEquipment Failure AnalysisWastewaterUrban wastewater treatmentSewage treatmentbusinessControl and automation (ICA)Demonstration plant
researchProduct

Obtención de los principales parámetros del agua residual urbana empleados en los modelos matemáticos de fangos activados a partir de una caracteriza…

2017

El tratamiento de las aguas residuales se ha realizado en España mediante procesos biológicos como el comúnmente utilizado de fangos activados. Estos procesos han sido descritos mediante modelos matemáticos que describen la eliminación de los contaminantes presentes en el agua (materia orgánica, nitrógeno y fósforo). La utilización de estos modelos requiere de una caracterización detallada de los contaminantes presentes en el agua residual urbana (ARU). La caracterización de un ARU es clave para el uso de estos modelos de simulación, tanto en el diseño como en la simulación de las Estaciones Depuradoras de Aguas Residuales (EDAR). Este trabajo ha utilizado y considerado los parámetros propu…

Activated sludgeWastewaterAigües residualsSimulation modelingEnvironmental engineeringEnvironmental scienceSewage treatmentAigua Qualitat
researchProduct

A systematic approach for fine-tuning of fuzzy controllers applied to WWTPs

2010

A systematic approach for fine-tuning fuzzy controllers has been developed and evaluated for an aeration control system implemented in a WWTP. The challenge with the application of fuzzy controllers to WWTPs is simply that they contain many parameters, which need to be adjusted for different WWTP applications. To this end, a methodology based on model simulations is used that employs three statistical methods: (i) Monte-Carlo procedure: to find proper initial conditions, (ii) Identifiability analysis: to find an identifiable parameter subset of the fuzzy controller and (iii) minimization algorithm: to fine-tune the identifiable parameter subset of the controller. Indeed, the initial locatio…

EngineeringFine-tuningMathematical optimizationEnvironmental Engineeringbusiness.industryEcological ModelingControl variableTrial and errorFuzzy logicLatin hypercube samplingControl theoryControl systemIdentifiabilitybusinessSoftwareEnvironmental Modelling & Software
researchProduct