A Study On Sewage Concentration Detecting Device Based On Ultrasonic Attenuation

One of the main ways to prevent and control water pollution is sewage treatment. A large portion of sewage belongs to suspension, one important indicator to indicate its character is mass concentration, so detect the sewage’s mass concentration in water treatment is an important means of evaluating the water quality. Nowadays there are many different methods to detect concentration. These methods have both advantages and disadvantages, but because of the limitation of use conditions, they are not applicable for sewage. Compared with these methods, ultrasonic concentration measurement with accurate detection, convenient application and harmless to humans. The main content of this thesis is about the study on ultrasonic concentration measurement.Based on a summary of domestic and international research about ultrasonic concentration detection,this paper focus on the measure method with ultrasonic attenuation.On the basis of theory, we designed an equipment to do experiment.The experiment verifies the correct theory analysis.Chapter 1 is the introduction of this paper,this part points out the meaning of the study, compares several methods and declares the advantage of ultrasonic method. Then it summarizes detection principle, and introduces the research results at home and abroad briefly.Chapter 2 is the theoretical basis of ultrasonic detect method. We analyze the chemical composition in sewage, study the ultrasonic propagation characteristics and its attenuation characteristic in sewage.Chapter 3 explores several classical model for ultrasonic attenuation proposed by scholars at home and abroad on the basis of Chapter 2. We compared Lamb-Urick model, Epstein model and TangYingwu model and simplified the models to analysis ultrasonic attenuation regularities.Chapter 4 is the part to set up the experiment hardware facilities, choose the applicable ultrasonic transducers and debug all the functional module.Chapter 5 is the experiment verification part of this paper, We compound several groups turbid liquid of different mass concentration and detect them with the experiment hardware facilities we build in Chapter 4, record and analyze all the test data. Relation curve is fitted at last.Chapter 6 is the full text summary and work outlook. Sum up the essay and point out their merits and defects of this study, then prospect about the future research work.