جستجوی مقالات مرتبط با کلیدواژه "پساب نفتی" در نشریات گروه "مهندسی شیمی، نفت و پلیمر"

While the petroleum industry plays a significant role in the global economy, it also produces a considerable amount of oily wastewater, posing environmental challenges. Petroleum wastewater contains diverse pollutants, including phenol, sulfide, ammonia, petroleum hydrocarbons, mercaptans, oil, and grease. Therefore, petroleum wastewater and oil-water emulsions are considered two of the main environmental pollutants. Various methods like gravity separation, sand filtration, chemical treatment, membrane filtration, biological treatment, advanced oxidation processes, and electrochemical treatment are employed to treat petroleum wastewater. Among the methods used to treat these contaminants, the use of polymeric ultrafiltration membranes has attracted significant attention due to reasons such as high separation efficiency, cost-effectiveness, and process simplicity. This research presents the results of experimental studies on the treatment of petroleum wastewater using the ultrafiltration process. For the experiments, a handmade modified polysulfone membrane was used as the ultrafiltration membrane, and a sample of sour water produced from Mozdouran layer wells was used as the feed. The effect of operational conditions, including the applied pressure difference across the membrane and the feed temperature, on the permeate flux and pollutant removal efficiency, was investigated. The results indicate that increasing the effective pressure difference and temperature increases the permeate flux. At a constant temperature of 25 °C, increasing the pressure from 3 to 5 bar results in an increase in COD and turbidity removal by 29% to 40% and 55.31% to 74.41%, respectively, while the removal efficiency of electrical conductivity and TDS decreases from 29.45% to 21.3% and from 28.2% to 22.3%, respectively. Additionally, the removal efficiency of H2S decreases from 86% to 55%.

In this study four types of ceramic microfiltration membranes were fabricated by extrusion and sintering method; Mullite, mullite-alumina, mullite-alumina-zeolite and mullite-zeolite membranes. In order to ensure the correct fabrication of membranes, fabricated membranes were subjected to characterization tests such as scanning electron microscopy (SEM), X-ray diffraction (XRD), porosimetery, mechanical strength and mean pore size calculation. Synthetic oily wastewater were treated by these membranes in microfiltration-adsorption hybrid process. Effect of Powdered Activated Carbon (PAC) concentration on the membrane permeation flux, oil removal efficiency, turbidity and COD removal were investigated. Results showed that in mullite, mullite-alumina and mullite-alumina-zeolite membranes, highest permeate flux obtained in 800 mg L-1 of PAC concentration. For mullite-zeolite membranes addition of 200 mg L-1 PAC concentration lead to highest permeate flux. Addition of PAC with any concentration in all membranes increased oil removal, turbidity and COD removal percent significantly.

This study deals with modelling of aerating - permeation process for removal of VOCs from wastewater. The hybrid process allows desorbed VOCs from aerating process to be subsequently recovered using a membrane based vapour permeation process. A mathematical model has been developed to describe the mass transfer in both processes based on the resistance in series model. The separate evaluation of feed phase and membrane phase resistances has been carried out at different feed hydrodynamic conditions in a constant membrane thickness. A sensitivity analysis has been carried out using the developed model to investigate the effects of operational factors such as temperature, pressure, feed concentration, gas and liquid flow rate on separation performance of the process. As typical cases, removal of four VOCs, i.e. 1,2-dichloroethane (DCE), 1,1,2-Trichloroethane (TCE), Chloroform and Dichloromethane from water was investigated in a hybrid process consist of a stripping column of 90 cm height and vapour permeation unit employing PDMS membrane with an effective area of 14.7 cm2. The results indicated that while the gas phase resistance was negligible in air stripping process, it played a significant role in vapour permeation process, especially in feed side. The modelling results demonstrated that the air/water ratio has a great impact on the removal efficiency of air stripping process, but it should be limited to prevent flooding. The examination of the hybrid model has shown that the hybrid process has high efficiency for high concentrations, high gas flow rates and optimal temperature.

The lack of Pressurized Sand Filters in waste water treatment of desalting plants causes some problems like plugging of injection wells, scaling in the pumping system of transfer pipe lines and waste water injection in the disposal wells. In addition to the operational and economic difficulties, waste water disposal to the environment has produced a lot of acute banal environmental impact problems. Because of the impossibility of supplying the material garnet which constituted bed of the filters these apparatuses had been out of the waste water treatment services. To rehabilitate the filters, sand particles and activated carbons were supplied from Iran's market and loaded in the filters. Then efficiency of these filters was determined for oil and suspended solids removal from wastewater. This report reflects the result. The results indicated that the performance of the new media in decreasing pollutant load were well and acceptable. The new media is capable to remove 55 percent oil and 65-70 percent solids from desalting plant waste water.