Study On On-line Water Toxicity Biomonitor Instrument

With the great increase of human industrial production and argricultural activity, the variety and toxic effect of pollution source of water bodies are becoming more complicated, especially, owing to the imperfect of detection standard and lack of ecotoxicological data, the analysis of water comprehensive toxicity is necessary. The ecology risk assessment and the important component of environment risk assessment, is the quantitative estimation method for evaluating the negative effect probability and intensity of the environment does to the human kind. Ecology risk assessment for toxic chemicals refers to the forecast of the harmful effect the environment pollutant might does to the ecosystem. The on-line monitoring technology was gradually developed to conform to the need of water quality evaluation, and the traditional online detection technologies were main aimed at regular water indices, such as Dissolved Oxygen(DO), Chemical Oxygen Demand(COD), conductivity. These indices are able to reflect water quality, but they cannot accurately reveal the harm to human health that caused by pollutants. Currently, the mainstream research area is online biomonitoring technology of water quality, which takes advantage of live aquatic organisms. When the water quality having been changed or polluted, the ecological behavior of aquatic organisms can response in-phase, and the test data are automatically recorded. Namely, biomonitoring technology analyzes characteristics of water quality from the view that biology, Using the ecology, the biology and chemistry analysis means to forecast the injury probability that the appraisal toxic substance to the ecosystem. Thus, it can meet the management needs of water resources.This reseach subject developed an on-line water toxicity biomonitoring instrument, which based on the bioluminescent bacteria assay method. The instrument with optoelectronic detection technique and virtual instrument technique were designed. Finally, this apparatus was integrated as a high-automatical, powerful environmental adaptation, sensitive system, which usually was used on source water protection, municipal sewage supervision and waterworks management. The on-line water toxicity biomonitoring instrument hardware mainly includes the following parts: pretreatment devices, weak light detection module, signal acquisition and control, flow analysis, bioreactor, constant temperature fittings, and personal computer(PC). Based on the design of hardware , the on-line water toxicity monitoring instrument's software system is designed in virtual instrument's configurable software platform LabVIEW. The function module included device's drive, signal acquisition and processing, realtime monitoring, data management, remote warning ,and so on.On the basis of fundamental machine, a series of experiments has been executed and developed, from which many operational parameters of the advanced model machine were obtained. As follows, bioluminescent bacteria deepfreeze-revived method was researched for keeping bacterial activity by static culture and growth kinetics; Designing some different specifications pretreatment devices toward simulation test of distinctive water bodies, then many relevant pretreatment schemes were established; Rapid testing af Zn2+, Cu2+, nitrobenzene and phenol has been conducted and has been set up a reasonable operating mode for the on-line water toxicity biomonitoring instrument; The advanced model machine was set beside water body, such as lake, reservior, river, sewage plant, for testing its continuous running, its performance and availability being conformed.This reseach reveals that the advanced model biomonitor system is able to realize bioluminescent bacteria activity maintenance by way of optimizing control parameters and the program assure that the machine can run continuously with precise and reliable results. In particular, the design ideas which integrate reactor, detector, coiled pipe, plunger pump and temperature controller as a group achieve multi-channel monitoring, which greatly increased the machine's application value.