Immobilized multi-species based biosensor for rapid biochemical oxygen demand measurement

To improve the practicability of rapid biochemical oxygen demand (BOD) method, we proposed a stable BUD sensor based on immobilizing multi-species BODseed for wastewater monitoring in the flow system. The activation time of the biofilm was greatly shortened for the biofilm prepared by BODseed in the organic-inorganic hybrid material. Some influence factors such as temperature, pH, and concentration of phosphate buffer solution (PBS) were investigated in detail in which high tolerance to environment was validated for the BOD sensor permitted a wide pH and PBS concentration ranges. The minimum detectable BOD was around 0.5 mg/l BOD under the optimized 1.0 mg/ml BODseed immobilized concentration. The as-prepared BOD sensor exhibited excellent stability and reproducibility for different samples. Furthermore, the as-prepared BOO biosensor displayed a notable advantage in indiscriminate biodegradation to different organic compounds and their mixture, similar to the character of conventional BOD5 results. The results of the BUD sensor method are well agreed with those obtained from conventional BOD5 method for wastewater samples. The proposed rapid BUD sensor method should be promising in practical application of wastewater monitoring. (C) 2010 Elsevier B.V. All rights reserved.