Preparation Of Bioflocculant By Remaining Sludge And Their Application In Oilfield Produced Water Treatment

China's management rate of polluted water has reached over 85% after the Twelfth Five Year Plan. However, the output of remaining sludge, the accessory substance of sewage disposal system, is now growing year by year and traditional dewatering technology could only reduce the rate of water content in muds to 80%. The main components of the microorganism in the sludge are the organic components of polysaccharides or proteins, which is valuable in certain recycling. Some intracellular substances are also active in a certain flocculation. At present, chemical coagulation is a common method in the oil field wastewater treatment system. The use of inorganic flocculants will produce a lot of chemical sludge. It will produce more pollution if dealt with improperly. It will not only achieve the sludge reduction, harmless, resources, environmental protection but also reduce sludge output of oil system of chemical production, if the residual sludge of city sewage are utilized properly and the effective flocculation substance can be extracted and applied to oilfield wastewater treatment.The essay will finally summarize the preparation method of flocculants by comparing the flocculation activity in ultrasonic method, alkali hydrolysis method and influencing factors of the sludge hydrolysate and by comparing the flocculation rate and the CODcr dissolution under the unit energy consumption, using the the bio-chemi-sludge from the first sewage treatment plant in Panjin City as raw materials. The results show that ultrasonic method, alkali hydrolysis method and freezing-thawing method can all extract bio flocculants from remaining sludge. The bio flocculants are the most active if it is made when the power density is 1.5 W/m L and the ultrasonic time is 20 min. Its flocculation rate is 97.25%. The main influencing factors are the concentration of sludge solution, the times of freezing and thawing cycles when bio flocculants are made through freezing and thawing method. The influence of different freezing and thawing cycles on the preparation of biological flocculants is limited. The flocculation rate of suspended matter in oil field wastewater was 97.89% when it is made through alkali method. It can be concluded that the bio flocculants are the most active the amount of flocculants are the most in the condition of unit energy consumption when it is made through the alkaline hydrolysis method by comparing the energy consumption ratio of the flocculants and.A group of the flocculants' indexes in the application of water treatment parameters can be concluded by making biological flocculants BF-1according to the experimentally determined parameters, using the oil settling tank effluence in Teyi Combined Station of Liaohe Oil Field the as an example. The suspended solids and silicon dioxide can be researched by analyzing the factors influencing flocculation effect through single-factor method and multi-factor orthogonal experiment method. The results show that BF-1 has a good flocculation effect on the oil settling tank effluence in Teyi Combined Station of Liaohe Oil Field. The removal rate of suspended matter and silicon dioxide in water was higher than that of 90%, among which p H value was the main influencing factor for the removal of suspended solids. The strength of influence effect is as follow: p H value > hydraulic conditions > temperature > coagulant dosage > flocculants dosage PAM. It can be concluded through the experimental analysis that the optimum indexes for bio flocculants BF-1 in the settlement of tank effluence in Teyi Combined Station of Liaohe Oil Field are as follow : Hydraulic condition: the first stage: the stirring speed of 150 r/min, stirring time of 30s; the second stage: the stirring speed of 30 r/min, stirring time 300s; p H 12; the temperature should be the field temperature. The dosage of flocculants was 1m L/L; coagulant dosage of PAM is 2 ppm.