ساخت و ارتقاء حسگر زيستي بر پايه ي سلول ميكروبي به منظور اندازه گيري BOD محلول

چكيده انگليسي :

78 Construction and Development of Cell Based Biosensor to Measure Soluble BOD Behnam Mahdavi b mahdavi@ce iut ac ir Date of Submission Department of Chemical Engineering Isfahan University of Technology Isfahan P7 S P Iran Degree M Sc Language FarsiSupervisor Hamid Zilouei hzilouei@cc iut ac irAbstractWastewater production and its subsequent treatment is a major problem for every industry and for the societyas well Monitoring the wastewater characteristics is necessary in order to evaluate the performance oftreatment processes as well as to permit their discharge into the local water resources Biochemical oxygendemand BOD is one of the most important and frequently used parameters for monitoring water andwastewater which is estimated by determining the amount of oxygen required by aerobic microorganismsdegrading organic matters The BOD value represents the amount of biodegradable organic compounds Thestandard method to measure biodegradable organic levels in wastewater is day biochemical oxygendemand assay BOD The conventional BOD test has certain benefits such as being a universal method ofmeasuring most wastewater samples and furthermore no expensive equipment is needed It has however the limitations of being time consuming and consequently it is not a suitable method for on line processmonitoring The control of wastewater treatment plants is very difficult or even impossible using the classicaldetermination method for BOD because of its long measurement time days The need for fast portableand cost e ective methods for environmental monitoring has stimulated the development of biosensors Biosensors have several unique features such as compact size simple to use one step analysis no need toreagent low cost and quick real time results The conventional BOD measurement requires days while amicrobial BOD biosensor senses within minutes In this project a microbial based biosensor for BODdetermination was designed and developed A Clark cell as the transducer and activated sludge collectedfrom Water and wastewater treatment plant of Shahinshahr was used as the biological receptor Inthe construction of Clark cell Ag Pt and KCl were used as anode and cathode electrodes andelectrolyte respectively The effects of the volume of sludge immobilized on the Nylon membrane pH of carrier fluid carrier fluid flow rate and sample injection volume on the biosensor performancewere studied The optimum values for volume of sludge immobilized on the Nylon membrane pHof Carrier fluid Carrier fluid flow rate and sample injection volume were obtained equal to l T ml min and ml respectively According to the results obtained from the biosensorcalibration a linear relationship between the current change and a glucose glutamic acid GAA concentration up to 7P mg L was observed The BOD values of wastewater inlet and outlet of treatmentplant of Ardine company wastewater inlet and outlet of wastewater treatment plant of Shahinshahrand wastewater outlet of treatment plant of Pegah company were measured using current developedbiosensor Comparison of the results of the biosensor with the results of the conventional BODmeasurement BOD shows that the mean percentage error measured by the sensor is S 7 Theresults concerning the stability of the designed biosensor showed that stability time of the sensorresponse was days which after that the activated sludge immobilized on the sensor must bereplaced Keywords Cell based biosensor wastewater BOD activated sludge flow injectionanalysis

مهدوي، بهنام

ساخت و ارتقاء حسگر زيستي بر پايه ي سلول ميكروبي به منظور اندازه گيري BOD محلول

پساب , اكسيژن خواهي بيو شيميايي , لجن فعال , آناليز تزريق جريان