كليدواژه :
غشاي مايكروفيلتراسيون , غشاي اولترافيلتراسيون , غشاي الياف توخالي , پساب نمك زدايي , تزريق به چاه دفع
چكيده لاتين :
The rapid boost of wastewater volumes produced in the world is opening a new market for membranes, which have a significant potential to take the role as the main technology for these applications. today, an increasing number of wastewater treatment facilities are using membrane technologies, and this number is growing year by year. Membranes processes have high selectivity values required to achieve high water and wastewater quality standards, are more cost-effective than other conventional processes, require less area, and can replace several unit treatment processes with a single one.
In the past years, microfiltration (MF), ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) membranes, as well as membrane bioreactors (MBRs), have been increasingly implemented in water and wastewater treatment processes such as groundwater, desalination of brackish water and seawater, and decontamination of wastewater of diverse nature and sources, e.g., including urban wastewater, coking, carwash, nuclear power, power engineering, steel industry, textile and tannery, pulp and paper, pharmaceutical, and agro-food industries, such as dairy, beverage, winery, tomato and olive oil, among others. Other membrane processes, such as electrodialysis (ED), membrane distillation (MD) and forward osmosis (FO) are also being explored.
Produced water is the largest waste stream generated in oil and gas industries. It is a mixture of many organic and inorganic compounds. Because of the increasing volume of waste all over the world in the recent decade, the outcome and effect of discharging produced water on the environment has lately become a significant issue of environmental concern. Produced water is conventionally treated through different physical, chemical, and biological methods. In offshore platforms because of space constraints, compact physical and chemical systems are used. However, current technologies cannot remove small-suspended oil particles and dissolved elements. Besides, many chemical treatments, whose initial and/or running costs are high produce hazardous sludge. As high salt concentration and variations of effective characteristics have direct influence on the turbidity of the effluent, it is appropriate to incorporate a physical treatment, e.g., membrane to refine the final effluent. For these reasons, major research efforts in the future could focus on the optimization of current technologies and use of combined physico-chemical and/or biological treatment of produced water in order to comply with reuse and discharge limits.
The objective of this study was to evaluate the feasibility of treating desalting plant produced water to meet the applicable flow rate limits and injection to well standard consistently using single and hybrid membrane processes to reduce the risk of clogging of the injection well. The treated effluents of two sand filtration units from Aghajari maroon were used as feed. A Pilot scale hybrid membrane unit with a spun polypropylene of 0.45 μ pore size microfilter and a hollow fiber polypropylene of 0.1 to 0.01 μ pore size ultrafilter membrane were used in this study. Trials on different membrane fluxes were conducted for two processes: microfiltration, and hybrid micro and ultrafiltration processes. Results show that flow rate of 32 LPM was more applicable. The optimal flux was 120 LMH. The average removal percentages of Turbidity, Oil and grease, TSS and particle size were 98.53, 98.81, 98.23 and 99.93, respectively. The results showed that the quality of the product consistently met the requirements for well injection. It is concluded that it is feasible to treat the produced water using micro and ultra filters.
