George Nakhla
Contact
Department of Civil and Environmental Engineering
Spencer Engineering Building,
Room SEB 3037
Western University
Tel: 519-661-2111 ext. 85470
Fax: 519-661-2921
gnakhla@uwo.ca
Projects
Ongoing Projects
Treatment of Oily Pet food Wastewater in a Hybrid UASB-FBR system with immobilized Lipase:
A laboratory scale fluidized bed reactor (FBR) hybrid with an upflow anaerobic sludge blanket (UASB) is used to investigate the possibility of anaerobically treating pet food rendering wastewater with an oil and grease concentration as high as 80g/L. The primary advantage of this approach over physio-chemical oil removal i.e, DAF is potential elimination of DAF, production of energy i.e., methane from dissolved oils and elimination of disposal requirements for odorous oily sludges.
Aerobic Thermophilic Membrane Bioreactor Treatment of Pet food Wastewater:
The objective is to investigate the applicability of aerobic thermophilic membrane bioreactor in treating high strength rendering wastewater. The study includes monitoring the effects of temperature (40˚C and 45˚C) in a continuous MBR at lab-scale and determining kinetic parameters through respirometric experiments. This treatment technology minimizes biological sludge productions which is critical for high strength wastewater.
Electrokinetic Treatment of Oily sludge:
The objective of this research is to investigate the effect of electrokinetic processes on the removal of water and oil from the sludge to achieve the goals of increasing solid content and recovery of oil. In this research work, experiments are conducted with two different configurations of electro-dewatering cells, i.e. vertical and horizontal positioned electrodes. This technology offer potential for enhanced oil recovery as well as reduction of water content of sludges by more than 50%.
Treatment of High Strength Pet food Wastewater Using Two Stage Membrane Bioreactors:
The objective of this work was to develop a novel process to treat DAF pretreated effluent to meet surface discharge criteria, accommodating high variations in the organics and nutrient loading. The advantages of this process include generation of recyclable effluent quality, far superior to surface water discharge criteria at relatively short contact time.
Treatment of high strength tomato processing wastewater by Upflow Anaerobic Sludge Blanket (UASB) reactor followed by anoxic-oxic stage:
A UASB reactor followed by anoxic-oxic process was used to study the treatablility of tomato processing wastewater. The advantages of this system are lower sludge yield, methane gas generation which is potential source of energy and achievability of stringent effluent discharge criteria.
Biological Nutrient Removal using Circulating Fluidized Bed Reactor (CFBBR):
The objective of this research work is to develop the biological nutrient removal (carbon, nitrogen and phosphorous) process using circulating fluidized bed bioreactor (CFBBR). This process has certain unique advantages over conventional processes, such as lower HRT, reduced sludge generation, small foot print, and tertiary effluent quality.
Past Projects
Design of an Integrated Hazardous Waste Treatment Center, Qatar (2001). This project involves a survey of industrial and hazardous wastes for the entire state of Qatar, feasibility study of the HWTC, conceptual and detailed design of the material handling and processing facilities incorporating liquid hazardous waste treatment, stabilization/solidification, landfilling, landfarming, and incineration facilities.
ESR for Upgrade of the Town of Hawkesbury Water Pollution Control Plant, Hawkesbury, Ontario (2001). Alternatives for management and treatment of high sewage flows, particularly wet weather flows, including sewer rehabilitation, water conservation, separation of combined sewers, and WPCP upgrade are evaluated as part of the Class Environmental Assessment.
Optimization of Seaway WPCP, Region of Niagara, Ontario (2001). This project involves performance assessment of the existing activated sludge system, with emphasis on the impact of high industrial wastewater contribution, particularly from CASCO. The optimization study will identify corrective measures to the operational problems of poor sludge settleability, foaming, and high loadings from internal recirculation streams, as well as determine any pretreatment requirements for the industrial wastes.
Optimization of Chemical Wastewater Treatment at Stepan Canada, Ontario(2000). The on-site industrial wastewater treatment plant, utilising an extended aeration plant for the treatment of a variety of phenolic-type wastes, experienced several exceedances of effluent DOC, TSS, O&G, and TP criteria. This project involved process assessment, respirometry and biodegradation kinetics studies, as well as process modelling to delineate process limitations and evaluate optimization measures.
Expert Witness Testimony at Ontario Municipal Board, Goulbourn Township, Region of Ottawa-Carelton,Ontario (2000). This project involves testifying as an Expert Witness in Wastewater Treatment at an OMB hearing for the Village of Munster Hamlet Wastewater Treatment Alternatives Evaluation, and supporting litigation in cross-examining appelants’ witnesses.
Mobile Pilot Plant Testing of the Pseudoliquified Activated Sludge Technology at Kiev Wastewater Treatment Plant (2001). This one year Technology Demonstration Project is funded by the Federal International Development and Research Council (IDRC), and aims at constructing a mobile unit of an innovative tertiary wastewater treatment technology and testing it at the 32 mgd Kiev sewage treatment plant.
Treatability Studies, Pilot Testing, and Process Design of Leachate Treatment Facility at Imola Landfill, Bologna, Italy (2000). This project scope includes design of bench and pilot-scale treatability studies, determination of design parameters, and development of conceptual design for the leachate treatment facility.
Upgrade of the Ingersoll Water Pollution Control Plant, Ingersoll, Ontario (2000). This project scope involves the conceptual and detaileddesign of a new aeration system, a new secondary clarifier, replacement of headworks, modification of disinfection from chlorination to UV, and conversion of anaerobic sludge digesters to aerobic for a 10,200 m3/d facility.
Conceptual and Process Design of Leachate Treatment Facility at Green Lane Landfill, London, Ontario (2000). This project scope includes design of a 130 m3/d leachate treatment system incorporating primary, biological, and tertiary treatment systems, including wetlands, as well as procurement of C of A, and system startup.
Design of Neutralization Facilities, Horizon Poultry, Ayr, Ontario (1999). Flow and pH studies were conducted to establish design basis for neutralization facilities. A conceptual design for the neutralization tank prior to the existing BNR treatment facilities was developed with implementation being underway.
Design of Odour Control Facilities, Horizon Poultry, Ayr, Ontario (1999). Technologies for treatment of 2,500 cfm of malodorous air from the wastewater treatment facilities were evaluated. A two‑stage scrubbing system is currently being designed.
Feasibility Study of Biological Phosphorous at Packard, Pollution Control Plant, Ottawa, Ontario (1999). A computer model of this 520,000 m3/d was developed and calibrated. Process modelling was used to determine the feasibility and potential savings resulting from conversion to a biological‑phosphorous removal system.
Treatment of Chemical Wastewater at Naugatuck POTW, Naugatuck, Connecticut (1999). Conceptual design for the treatment of process wastewater from Uniroyal at the local POTW utilizing separate liquid and sludge processing facilities was developed. The fate of various VOCs and SVOCs during biological treatment was evaluated using computer modeling.
DAF Sludge Dewaterability, GM Powertrain Division, Bay City, Michigan (1999). The poor dewaterability of high oil content DAF sludges was significantly enhanced by modification of the chemical treatment of process wastewater, and chemical conditioning of sludges to eliminate oil cooking operations. Laboratory-scale filter press and full-scale frame-press trials were not only successful in achieving stable sludge cakes but also demonstrated a significant reduction in operating costs.
Design of a Groundwater Treatment System, Guelph, Ontario (1999). Process Design of treatment system for groundwater characterized by high hardness, alkalinity, iron and VOCs concentrations as part of a site remediation program. Various VOCs as well as pretreatment technologies were evaluated to select optimum process configurations.
Design of Pretreatment Facilities, Armstrong Cheese, Oakville, Ontario (1999). The project involved investigation of the under performance of existing process wastewater pretreatment facilities consisting of equalization and neutralization as well as expansion of the pretreatment facilities by 200 percent to treat all process wastewater. Process modifications allowed expansion of the treatment capacity within the existing tankage and at minimum capital expenditure.
Process Design, Startup, and Commissioning of Communal Wastewater Treatment System, Heidelberg, Ontario (1998-1999). This project involved the design of a 131 m3/d BNR system to treat municipal wastewater from a new development to meet stringent effluent quality criteria. The treatment system was commissioned to treat flows of <10 percent="" of="" the="" system="" design="" capacity="" and="" continues="" successfully="" to="" operate="" at="" about="" 7="" flow="" p="">
Modification of Secondary Clarifier at Ingersoll Water Pollution Control Plant, Ingersoll, Ontario (1998). The project involved modification of headworks, replacement of sludge collection mechanism and effluent launders, installation of automatic scum control mechanisms, and modification of scum pumping system.
Cost Estimation of Overall Plant Upgrade, Ingersoll Water Pollution Control Plant, Ingersoll Ontario (1998). Detailed cost estimates for modification of conventional activation sludge system to BNR, replacement of surface aeration system with high‑efficiency diffused aeration, conversion from anaerobic sludge digestion to aerobic, were developed. Alternative implementation scenarios and project staging were evaluated.
Conceptual Design of a BNR System for Rendering Wastewater, Moorefield, Ontario (1998). Process design for the retrofit of the existing underperforming conventional activated sludge system to a BNR utilizing sludge prefermentation was undertaken and a Certificate of Approval was procured.
Investigation of Discharge Contributions of Various Operations for Site Contamination at Liberty Industrial Facility, Farmingdale, New York (1998). The project involved tracking of the chromium and heavy metal contamination contributed to various operators throughout the Site history and assessment of cleanup costs to be incurred by the potential responsible parties (PRP).
Treatment of Quench Wastes at the Sanitary Wastewater Treatment Plant at GM, Bay City, Michigan (1998). This project involved conducting bench-scale and full-scale testing of the biological treatability of quench wastes, design of oil/water separator, and modifications to the SWWTP to accommodate a 10‑fold increase in organic loadings within the existing processes.
Retrofit Design of Wastewater Treatment Facilities at Strathroy Foods, Strathroy, Ontario (1998). Process design for the retrofit of the existing under performing system to improve effluent quality and achieve compliance, also reducing sludge management costs by incorporation of sludge digestion within the existing process tanks.
Treatment of Cyanides Wastes at BYG Gold Mine, Yellowknife (1998). This project involved troubleshooting of the existing Inco treatment process to improve effluent quality and reduce effluent toxicity to fish. Pilot scale tests were conducted and corrective measures were delineated.
Performance Assessment of Biological Treatment System at Maple Leaf Poultry, Canard, Nova Scotia (1998). The project evaluated the under-performance of the 2,100 m3/d extended aeration system with integrated aeration tank/clarifiers at one‑third of the design flows. Corrective measures including conversion to BNR system and incorporation of sludge management were identified.
Remedial Alternatives for Irrigation Sprayfield, Williamstown, Ontario (1998). The environmental impact of spraying dairy wastewater onto summer and winter sprayfield was assessed. Both groundwater and surface water quality monitoring data were analyzed and remedial alternatives were identified and evaluated.
Evaluation of Upgrade for the Munster Hamlet Wastewater Treatment System, Ottawa, Ontario (1998). The project involved evaluation of technologies for upgrade of the existing 600 m3/d wastewater spray irrigation field capacity to meet a effluent total nitrogen of 3.0 mg/L and total phosphorous of 0.03 mg/L. Technologies evaluated included spray irrigation and a combination of Snowfluent and Intermittent Sand Filtration, RBCs, and BNR plants.
Stabilization of Dresden Water Pollution Control Plant, Dresden, Ontario (1998). Process instabilities and filamentous bulking problems experienced at this 4,500 m3/d integrated aeration tank/clarifier plant as a result of occasional organic and suspended solids overloading were examined. Full-scale stabilization measures tested at the site included intermittent aeration, anoxic selector technology, and control of sludge SRT.