Online detection device for concentration of polyacrylamide in oilfield wastewater

The invention relates to an online detection device for the concentration of polyacrylamide in oilfield wastewater. The online detection device comprises a sampling part, a measurement part and a numerical control part, wherein the sampling part comprises a conveying pipeline, a liquid taking device, four valves, two pipe sections and an emptying valve; the measurement part comprises three mixing devices, three detection sections, three quartz windows and a diffusion pipe; and the numerical control part comprises three light sources, three monochrometers, three data acquisition units and a PLC (Programmable Logic Controller); the special liquid taking device is arranged on a polyacrylamide-containing oilfield wastewater conveying pipeline to enable the polyacrylamide-containing oilfield wastewater to enter the detection sections for optical detection, thereby obtaining three groups of measured multi-wavelength multi-absorbing-light-distance absorbance data, the absorbance data is transmitted to the data acquisition unit by a photoelectric sensor and then is received by the PLC, and the absorbance values of the oilfield wastewater with different polyacrylamide concentrations, stored in a database, can be compared automatically.