公开(公告)号：JPH03111759A

公开(公告)日：1991-05-13

申请号：JP25090989

申请日：1989-09-27

Applicant: AGENCY IND SCIENCE TECHN

Inventor： ISHIHARA YUTAKA ,  MOCHIZUKI MIYUKI ,  KAMATA EIJIRO

IPC: G01N33/18

Abstract: PURPOSE:To make quick speed and accuray compatible and to make it possible to measure BOD by a simple method by adding sulfite into suspension in activated sludge, and quickly decreasing the concentration of dissolved oxygen in the suspension. CONSTITUTION:The suspension of activated sludge which is well accelimatized to organic material in test water is agitated at a constant speed in a measuring container. The concentration of the dissolved oxygen in the suspension is continuously measured. In order to accelerate the decrease in concentration of the dissolved oxygen to the vicinity of 0 ppm by internal breathing, a solution of a specified amount of cobalt salt and a specified amount of sulfite is added, and the dissolved oxygen is quickly (within 10 minutes) consumed. The concentration of the dissolved oxygen is brought to the vicinity of 0 ppm under the state wherein the excessive sulfite is not present. Then the specified amount of the test water is added, and the solution undergoes aeration under the constant conditions. The required time for biochemical oxidation from the starting time of aeration to the rapid increasing point of the concentration of the dissolved oxygen is automatically measured. Then the BOD concentration can be obtained based on the relationship between the preset BOD quantity and the required time for the biochemical oxidation.

公开(公告)号：JPH06180312A

公开(公告)日：1994-06-28

申请号：JP10898491

申请日：1991-02-15

Applicant: AGENCY IND SCIENCE TECHN

Inventor： MIYAWAKI MIYUKI ,  KAMATA EIJIRO

IPC: G01N33/18

Abstract: PURPOSE:To measure a biological oxygen demand (BOD) of waste water simply, rapidly, and accurately by utilizing the phenomenon that a dissolved oxygen amount consumed by an added substrate is regularly proportional to an added substrate amount. CONSTITUTION:A suspension of active sludge well mixed with a substrate (organic compound) in a water specimen is aerated while mixing and stirring uniformly and saturated by dissolved oxygen; then in the state that the surface of the suspension contacts the outer air, a decrease in the concentration of dissolved oxygen in the suspension is continuously measured without aeration while an added substrate amount is varied. When a fixed amount of water specimen is added at point A after the elapse of a predetermined time to make a gradient in decrease of the concentration of dissolved oxygen equal to a gradient as preceding, BOD concentration can be measured from a difference DELTAQ1-DELTAQ3 of the concentration of dissolved oxygen between parallel lines of decrease in the concentration of dissolved oxygen. This enables unstable factors inherit to a prior art BOD measurement method to be overcome, thereby making rapidity and accurateness compatible overcome.