Synthesis and Mechanism of Flocculating-Decolorizing Agent PAD used for Polymer-Sulphonated Drilling Wastewater

Cationic polyacrylamide (PAD) is synthesized and used as decolorizingagent for polymer-sulphonated drilling wastewater. Compared with other widely useddecolorizing agents the wastewater processed by PAD results in a higher decolorizationspeed, lower chromaticity, and less flocs. It also adapts to polymer-sulphonateddrilling wastewater with different salinity. Used for on-site wastewater, it is both efficientand pleietrepie. It reduced the chromaticity to lower than 50 times while the COD isreduced to 100 mg/L and even much lower than 100 mg/L. Meanwhile, the suspendedsolids content is lower than 40 mg/L and the flocs content is very low. Therefore, theprocessing results may greatly help the following treatment. Fourier transform infraredspectroscopy (FTIR) and a scanning electron microscope (SEM) are used to analyzeinteraction between functional groups of PAD with the polymer-sulfonated drilling wastewaterand decolorizing mechanism. The decolorizing mechanism is mainly a union ofionic bonds, charge neutralization, and adsorption bridging between PAD and polymersulphonatedadditives.