Biodegradation of oil wastewater by free and immobilized Yarrowia lipolytica W29

The ability of Yarrowia lipolytica W29 immobilized by calcium alginate to degrade oil and chemical oxygen demand （COD） was examined. The degradation rules of oil and COD by immobilized cells with the cell density of 6.65 × 10^6 CFU/mL degraded 2000 mg/L oil and 2000 mg/L COD within 50 h at 30℃ （pH 7.0, 150 r/min）, similarly to those of free cells, and the degradation efficiencies of oil and COD by immobilized cells were above 80%, respectively. The factors affecting oil and COD degradation by immobilized cells were investigated, the results showed that immobilized cells had high thermostability compared to that of free cells, and substrate concentration significantly affected degrading ability of immobilized cells. Storage stability and reusability tests revealed that the oil degradation ability of immobilized cells was stable after storing at 4~C for 30 d and reuse for 12 times, respectively, the COD degradation rate of immobilized cells was also maintained 82% at the sixth cycle. These results suggested that immobilized Y lipolytica might be applicable to a wastewater treatment system for the removal of oil and COD.

Treating oil wastewater with pulse electro-coagulation flotation technology

Pulse electro-coagulation flotation was used to treat oil wastewater of high oil content.Different operational conditions were examined,including current density,reactive time,electrode distance,pH and pole switching time.Orthogonal tests were carried out to identify the optimal operational conditions for this technique.Considering the treatment cost and efficiency together,the optimal operational conditions were an electrode distance of 3.3 cm,pH of 4,current density of 49.38 mA/cm2,reaction time of 15 min and pole switching time of 10 s.The removal efficiency of oil wastewater under normal conditions reached up to 96.21%.The influences of different factors on removal efficiency were in the following decreasing sequence:pH> current density > pole switching time > reactive time > board distance.

Advanced treatment of oil recovery wastewater from polymer flooding by UV/H_2O_2/O_3 and fine filtration

In order to purify oil recovery wastewater from polymer flooding （ORWPF） in tertiary oil recovery in oil fields, advanced treatment of UV/H2O2/O3 and fine filtration were investigated. The experimental results showed that polyacrylamide and oil remaining in ORWPF after the conventional treatment process could be effectively removed by UV/H2O2/O3 process. Fine filtration gave a high performance in eliminating suspended solids. The treated ORWPF can meet the quality requirement of the wastewater-bearing polymer injection in oilfield and be safely re-injected into oil reservoirs for oil recovery.

Fenton treatment of olive oil mill wastewater—applicability of the method and parameters effects on the degradation process

The low biodegradability of polyphenolic compounds typically found in olive processing indicated that biological treatment is not always successful in the treatment of olive oil mill wastewater in term of COD removal. In this study the results of investigations on the applicability of Fenton's reagent in the treatment of this effluent were discussed. The efficiency of this method was determined. 86 % of removal COD was obtained using 5 mol H 2O 2 and 0.4 mol Fe 2+ per liter of crude OMW. The main parameters that govern the complex reactive system, i.e., time, pH, [H 2O 2] and [Fe(II)] were studied.

Performance and Modeling of an Up-flow Anaerobic Sludge Blanket(UASB) Reactor for Treating High Salinity Wastewater from Heavy Oil Production

In this study,an up-flow anaerobic sludge blanket(UASB) reactor was applied to treat the high salinity wastewater from heavy oil production process.At a HRT of ≥24 h,the COD removal reached as high as 65.08% at an influent COD ranging from 350mg/L to 640mg/L.An average of 74.33% oil reduction was also achieved in the UASB reactor at an initial oil concentration between 112mg/L and 205mg/L.These results indicated that this heavy oil production related wastewater could be degraded efficiently in the UASB reactor.Granular sludge was formed in this reactor.In addition,two models,built on the back propagation neural network(BPNN) theory and linear regression techniques were developed for the simulation of the UASB system performance in the oily wastewater biodegradation.The average error of COD and oil removal was-0.65% and 0.84%,respectively.The results indicated that the models built on the BPNN theory were wellfitted to the detected data,and were able to simulate and predict the removal of COD and oil by the UASB reactor.

Experimental Research on the Reusing & Recycling Technology of Oil Extraction Wastewater Treatment in Oil Field

How to use water resource effectively is an important problem in developing industry. Three combined processes which are composed of oil separator＋de-emulsification flocculation＋sand filtration （SDF）, oil separator q-hydrolytic acidification＋SBR （SAS） and oil separator＋de emulsification flocculation ＋SBR （SDS） are conducted in laboratory-scale experiment to treat oil extraction wastewater for an oil field. The experimental results show that the removal rate of COD（chemistry oxygen demand） and oil treated by SDF process are 85 % and 95 % respectively, the residual oil in effluent can meet the discharge standard, but the residual COD can not. The removal rate of COD and BOD （biological oxygen demand） of the SAS effluent are 85% and 90% respectively, the BOD can meet but the COD can not meet discharge standard. So the further treatment is required in the process. The SDS effluent with removal rate of 95% and 90% are obtained for COD and BOD respectively, which can completely meet the national standards of oil wastewater discharge and refilling （China）. The experimental result shows that oil extraction wastewater has turned into water resource after being, treated by SDS.

Removal of Heavy Metals （Copper, Manganese and Zinc） from Industrial Wastewater of Baiji Refinery by Granular Activated Carbon

The aim of the present work is to remove heavy metals （copper, manganese, and zinc） from industrial wastewater of Baiji refinery using GAC （granular activated carbon）. The most important factors affecting adsorption process have been studied, which are granular activated carbon thickness, H, inlet pollutant concentration, Cv, and liquid hourly space velocity, LHSV. All experiments were performed under constant temperature at 25℃ and pH = 7. The experimental apparatus was designed and constructed to enable controlling of the operating conditions. Employing five levels for each of H and LHSV and three levels for Co required 75 runs for each metal. Box-Wilson method was used to reduce the number of experiments to 15 for each metal. The results indicated that copper, manganese, and zinc can be completely removed from wastewater using activated carbon. However, breakthrough time for zinc is low. It is also shown that breakthrough time （TB） and exhaustion time （TE） are inversely proportional with pollutant concentration and LHSV （liquid hour space velocity） while it is directly proportional with the thickness of activated carbon column.

Preparation of Porous Ceramisite for Waste Water Treatment Made from Red Mud

The porous ceramisites for wastewater treatment were made from red mud, which is the industrial waste discharged from the production of Al2O3. The sintering process and the degreasing experiments with porous ceramisites have been finished. The results show that the sintering temperature control is dominant for the preparation of the porous ceramisites. The optimal sintering temperature is between 1 110-1120℃, a narrow range. The surface of ceramists is distributed with a lot of coarse holes with diameters of about 1-10μm. Moreover, the sintering temperatures have a great influence on the efficiency of degreasing, and the curve between the sintering temperature and the efficiency ofdegreasing is like a parabola.