INSTRUMENT FOR MEASURING RESPIRATION RATE

摘要

PURPOSE:To simplify construction by constituting a detecting part by a single measuring cell, providing a water sampling port which opens in treated water via a pinch valve to this measuring cell and providing an injection hole for adding allyl thiourea to a water drain pipe. CONSTITUTION:The water sampling port 13 is provided in the treated water via the pinch valve 11 to the lower side of the measuring cell 7 in the detecting part 2. The injection hole 13 for adding the allyl thiourea is opened to the top end of the water drain pipe 10. The pinch valves 11, 12 are then opened and the water W to be tested is passed into the cell 7 under the air lift by the aeration from a vent hole 21. The valve 11 is then closed to sample the water W into the cell 7. The valve 12 is closed while a stirrer 19 is kept operating. The time when the concn. of the dissolved oxygen in the cell 7 decreases to a prescribed value is measured. The respiration rate T of activated sludge is calculated from the concn. of the remaining dissolved oxygen decreasing per unit time. The allyl thiourea is added from the hole 15 into the water to be tested and the respiration rate A in the state of removing a carbon substrate from the water is measured. The respiration rate by the nitrogen substrate is calculated from the measured value T-A.