The Research About Chitosan-Based Flocculants Use For Waste Drilling Mud In Oil Field

Waste drilling mud is one of the major Pollutants Produce in petroleum field. If disposed with improperly, it would certainly enter the environment and Pollute local environment that results in inestimable loss. There were many methods to dispose the waste drilling mud and drilling wastewater, such as, Gravity Separation, Impact, solid-liquid, Baffle, or Spray Separation, Parallel Plate and Thin Film Separation and Vacuum Separation. The solid-liquid separation by flocculation was considered as the most important and widely application method. An inherent problem is relatively high moisture content of the de-watered product. So, an effective flocculant which can reduce the water content of the dewatered product.Cationic-based flocculants are suit for the petroleum field because Waste drilling mud in petroleum field takes negative change. It is one of the functions of the flocculants, which could neutralize the opposite charges in waste drilling mud. Another mechanism is bridge forming, where the big polymer molecule binds particles to itself by its functional groups. Bridging occurs when the adsorbed flocculant on one particle adsorbs onto a second one giving a doublet.Unfortunately, commercial available flocculants were not fit for petroleum system, not only because the unfit structure, the difficulty in water soluble, the low molecular weight, but the low charge density and high concentration. Furthermore, the majority of synthetic flocculants are obtained from petroleum-based row materials by processing chemistry, which is not always environmentally friendly.Cationic-based flocculants, as a natural polycations, has attracted numerous scientists because of its outstanding biological properties like biodegradability, biocompatibility and antibacterial activity. It has been extensively used in pharmaceutical systems, medicine, cosmetics, food, and agriculture and wastewater treatment. So, an easy soluble flocculant with high molecular weight, high cation degree and can deal with high density waste drilling mud is needed urgently.In this article, we prepared four new flocculants, which were Chitosan(CS)-grafted-acrylamide(AM), Chitosan acrylamide ethacryloyloxyethyl trimethyl ammonium chloride (DMC), Chitosan-grafted-acrylamide-ethacryloyloxyethyl trimethyl ammonium chloride (DMC)-SiO2 and Chitosan-grafted-acrylamide-ethacryloyloxyethyl trimethyl ammonium chloride (DMC)-TiO2.The optimum preparation conditions were determined by orthogonal test of four factors and three levels. The prepared four copolymers were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM) and Gel Permeation Chromatography (GPC). The solid-liquid separation properties were also investigated and the prepared flocculant showed great advantages than commercial products for high density waste drilling mud use.