The Study Of On-line Measurement And Information Acquisition On Biomass Concentration

With the high-speed development of Chinese industry, the volatile organic compounds (VOCs) into the atmosphere of are increasing. This organic waste gas deteriorates the nature environment, interferes human's daily life, causes serious harm.In the biological filter treat organic waste gas process, there are many factors impact the efficiency of biochemical reactions in the filter tower, such as nutrient composition of the biochemical solution, pH value, circulation flow rate, in tower temperature, biomass concentration, microbial activity .etc. In these factors, the biomass concentration is a significant parameter, carry out it on-line measurement is very important for people to supervision and control the biochemical reaction. The research shows that the on-line measurement of biomass concentration technology is immature, so it need design a new method of on-line measurement biomass concentration.The main research content as follows:(1) Puts forward a testing method for biomass concentration based on fiber reflecting energy attenuation technology. Seen from the Lambert-Beer law, the optical absorption coefficient is related to the medium consistence, optical path and incidence energy, this paper research just based on the physics phenomena and theory, related the receiving optical energy to the biomass concentration.(2) Based on the built measuring method, the author designed the on-line biomass concentration measuring sensor, researched on the sensor constitute theory, optical path and realization technology, carried out related experiment research. The result shows that the new method used on testing the biomass concentration is feasible.(3) Aiming at the solution temperature influencing the measuring result, put forward and designed the sensor with temperature unit. Improved the former ingle probe structure and introduced the double probe structure. This way make the sensor added measuring functions, which is biomass concentration measure and liquid temperature measure. The improved sensor has two channels, one is used to measure solution consistency and the other is used to measure reference liquid temperature change under the same measuring condition, which is established the base for eliminating temperature factor for measuring result.(4) Because biological filter process organic waste gas is very complicated, in order to enhance the on-line biomass concentration applicability, the author put forward soft measurement method which based on BP Neural Network to eliminate other nonlinear factors effect. In the experiment, used the measurement data to be the BP Neural Network training prepare data, built forecast model. The result shows that forecast value matched the experiment data, the error is under 0.005mv, soft measurement is feasible.This paper just researches on measurement one type bacterium solution, only studied the impact by temperature. In the part of intelligent information obtain, just work on soft measurement prediction estimate based on BP artificial neural network. In the biochemical reaction process for the multi-bacterium type, multi-reactant and multi-parameter crisis testing and other intelligent information obtain need more study.