バクテリアの種類と量：バクテリアが合わなかったり不足していると、有機物の分解が進まず測定値が低くなるため、植種が必要
採水により水とともに当然採取されるその水域の微生物の活動による酸素消費を計測することで、一定時間外部から酸素供給がなされない場合に、その河川水の溶存酸素がどこまで減少するかを指標化した。
Superior BOD stages are a result of large usage of dissolved oxygen by microorganisms. It signifies that the water is extremely polluted with natural matter.
The COD test needs to be deemed an unbiased measure in the organic matter in a wastewater sample instead of a substitute for that BOD test.
Continue to titrate right until the sample is clear. Report the number of digits demanded. (The colour may possibly reappear right after standing a couple of minutes, but this isn't a bring about for problem. The "to start with" disappearance with the blue coloration is considered the endpoint.)
In water samples exactly where more than 70% in the First oxygen is eaten, it can be crucial to aerate or oxygenate and dilute the sample with BOD-totally free water (de ionised glass distilled water) so as to stay clear of O2 pressure.
Việc thử nghiệm chỉ số BOD là phép đo tốc độ hấp thụ hết oxy của vi sinh vật có trong mẫu nước thử ở nhiệt độ cố định (twenty °C - mẫu thử nghiệm được đặt trong tủ ủ giống như tủ lạnh) và trong một khoảng thời gian chọn trước (thường là five ngày) trong bóng tối. Để đảm bảo mọi điều kiện là tương đương, một lượng rất website nhỏ vi sinh vật mầm mống được thêm vào trong mỗi mẫu cần thử nghiệm cũng như trong một mẫu đối chứng chỉ chứa nước cất.
The procedures for gathering and analyzing samples for dissolved oxygen consist of the next tasks:
The level of oxygen, taken up from the microorganisms that decompose the organic and natural waste make a difference in wastewater is recognized as biological oxygen demand or biochemical oxygen demand.
Organic and natural subject concentrations are growing as a result of a range of factors, the most of which are of human origin, like pollution.
The likelihood biological oxygen demand analysis method of Winter season fish kills improves if the fish inhabit a method which is contaminated or overgrown (overproductive).
A COD reactor/heating (one hundred fifty°C) block along with a colorimeter are turned on so that both of those instruments are permitted to stabilize.
Consequently, anaerobic micro organism (People that do not involve oxygen) begin to degrade the organic squander and produce chemical compounds using a foul odour which might be harmful to human overall health.
Major Effluent – Effluent from the key clarifier is yet another Excellent supply for seed. It's a benefit around influent in that it is "settled" seed, so most particulates will not be current from the seed. This eradicates the settling move.