tailieunhanh - Advances in Measurement Systems Part 8

Tham khảo tài liệu 'advances in measurement systems part 8', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 276 Advances in Measurement Systems 2. Objective of the study The inhibition of microalgal photosynthetic activity induced by different contaminants has been extensively investigated in the literature. Chen Lin 2006 reported the investigation on hazardous impact of volatile organic compounds VOCs using an air-tight algal toxicity assay. Nonetheless there has been no discussion on the effect of irradiance although the tested BOD bottles could be influenced by shading effect at high algal densities. Also the duration of the bioassay was not very short . 48 h in their study. With regard to algal biosensor a device for the monitoring of water toxicity in estuarine environments was reported in the work of Campanella et al. 2000 . The developed biosensor provides a new approach to the research on harmful effects of heavy metals herbicides and insecticides however no information on toxicity of volatile organic solvents was addressed using this system. Additionally a biosensor with an oxygen electrode containing Chlorella cells immobilized on the membrane was well established to detect VOCs in the form of aerosols Naessens Tran-Minh 1999 . Nevertheless one major drawback is that a controlled atmosphere chamber is required for the operation of this biosensor. Podola et al. 2004 described a non-selective sensor chips for the detection and identification of VOCs using different algal strains. Perhaps the disadvantage of the proposed multiple-strain biochip system is related to the complicate and expensive equipment which might be regarded as limitations for practical utilization. Consequently there is a need to design a simple and cost-effective indicator system that supports rapid toxicity detection of volatile and or hazardous substances. The aim of the present study is to design construct and validate a new algal biosensor-based measurement system that provides a rapid toxicity determination of pollutants. The apparatus allows the monitoring of photosynthetic efficiency