Brine generated at offshore and onshore oil recovery facilities is generally treated for removal of oil and suspended solids to meet process and regulatory requirements. Microfiltration (MF) and Ultrafiltration (UF) have been proposed as effective and cost-competitive alternatives to conventional oil removal technology. Recent studies in this field were reviewed to identify current trends and technical obstacles to the implementation of MF/UF technology for oilfield brine treatment. The most extensively demonstrated membrane technology for oilfield brine treatment in North America is a tubular ceramic microfiltration system which employs backflushing and chemical pretreatment. Two commercial installations of this technology are now in place, however, long term viability is uncertain. Lack of an adequate database on both membrane/brine interaction and long term system operations have mitigated against the development of predictive models and correlations necessary to design membrane processes for removal of oil from oilfield brine. The key technical obstacles to cost effective application of membranes include low average flux rates, flux degradation and uncertain membrane life. Concerns regarding integration of membrane processes at oilfield brine treatment facilities include sensitivity to variations in flow and oilfield brine characteristics, handling of waste streams generated using chemical pretreatment and requirements for extensive prefiltration.

No abstract

Since 1990, Canada’s Great Lakes 2000 Cleanup Fund, which is administered by Environment Canada, has been supporting the development and implementation of cleanup technologies to control municipal pollution sources, to clean up contaminated sediments, and to rehabilitate fish and wildlife habitats. These efforts are focused on Canada’s 16 Great Lakes Areas of Concern (AOCs) identified by the International Joint Commission for priority cleanup action and restoration of beneficial uses. Remedial Action Plans (RAPs) developed by federal/provincial teams and the public provide the strategy for restoring the beneficial uses of the AOCs. Impairments in beneficial uses in the AOCs have been, in part, caused by discharges from combined sewer overflows (CSOs), Stormwater and sewage treatment plants (STPs). To assist municipalities in addressing the problems posed by urban drainage (CSOs and Stormwater), the Cleanup Fund’s Urban Drainage Program has been supporting the development and demonstration of innovative, cost-effective technologies and approaches. These projects include high-rate treatment of CSOs, real-time control of CSOs, performance assessment of Stormwater treatment technologies, pollution prevention and control plans, and development of Stormwater management planning tools for urban areas. These projects are carried out in collaboration with the Ontario Ministry of the Environment, municipalities, professional groups, universities and conservation authorities and other Environment Canada’s facilities (National Water Research Institute and Wastewater Technology Centre). The Urban Drainage Program has been instrumental in advancing the state of the art in CSO and Stormwater management in Ontario. Projects supported under the program have quantified pollutant loadings from municipal wastewater sources in several Ontario Areas of Concern, provided hard data on the performance of best management practices for Stormwater treatment, identified and evaluated new cost-effective technologies for CSO reduction and Stormwater treatment, and developed strategies and decision-making tools for Stormwater management The work done through the Urban Drainage Program is making it possible for Great Lakes communities to achieve important environmental objectives at significantly lower cost As a result, the communities should be able to achieve many of these objectives much earlier than they would have if their choices had been limited to more conventional and capital-intensive solutions. Although the program has focused on the needs of Areas of Concern in the Great Lakes basin, the lessons learned there can easily be applied to communities in other parts of the country and around the world.

No abstract

Based on a preliminary economic and technical comparison, evaporation, membrane processes and freeze desalination were identified as the most attractive technologies for removing total dissolved solids (TDS) from produced water. Vapour compression evaporation appeared to be the most cost-competitive. Subsequently, laboratory-scale experiments on the evaporation of produced waters were conducted on four produced water samples from various locations in Alberta and Saskatchewan he evaporator consisted of a 4.6 m long titanium tube; 50.8 mm o.d. by 6.3 mm wall thickness, heated by steam to effect evaporation. Feed flow rate was 19 L/h and each run lasted 1.5 days. Feed TDS levels ranged from 12 000 to 64 000 mg/L. Oil and grease concentrations ranged from 10 to 310 mg/L. Depending on the level of scaling components in the produced water, the evaporator was run in a seeded or unseeded mode of operation. Produced water recoveries ranged from 67% to 93%. Heat transfer coefficients observed ranged from 3650 to 4050Im2.K. No operational problems with respect to foaming and fouling were observed. A preliminary cost estimate, based on heat transfer design parameters obtained, indicated that the capital cost would be approximately $8.9 million (1986 Canadian dollars) for a plant treating 3800 m31d 0/ produced water. Estimated annual operating costs ranged from $1.2 to $1.9 million and were dependent on the produced water characteristics and the mode of operation of the evaporator. Introduction The production of heavy oil and bitumen by in situ methods using steam flooding Or steam stimulation generates large volumes of water called "produced water". The most attractive strategy from an environmental viewpoint to handle this water is to reuse it as feed water for steam generation. However, at some locations in Alberta and Saskatchewan, produced water contains very high levels of total dissolved solids (TDS), with concentrations > > 8000 mg/L(1). This water is unsuitable for reuse in oilfield steam generators unless it can be treated to reduce the TDS concentrations to approximately 8000 mg/L or less(2). As part of an ongoing program dealing with the characterization and treatment of produced water, Environment Canada's Wastewater Technology Centre (WTC) is currently evaluating the technologies available for removing TDS from produced water. This paper presents the results of the first two phases of this evaluation:a literature review which identified the most promising processes, based on technical and economic factors, anda laboratory-scale experimental evaluation of vapour compression evaporation-one of the most promising processes. Status of Produced Water Recycling In situ recovery of heavy oil-bitumen by steam stimulation (or steam flooding) can generate 2 to 20 times as much water as oil, although in most cases, this ratio is approximately four(3, 4). Hence, the volume of produced water generated at some of these sites can be substantial. Water requirements for steam generation at these facilities can also be considerable. The water required for this purpose is approximately 5 to 6 times the volume of oil produced(5).