The Greatest Guide To biological oxygen demand test procedure
The Greatest Guide To biological oxygen demand test procedure
Blog Article
BOD measurement involves using two samples at Each individual web-site. A person is tested straight away for dissolved oxygen, and the next is incubated at midnight at 20 C for 5 times and afterwards tested for the level of dissolved oxygen remaining. The difference in oxygen amounts among the primary test and the 2nd test, in milligrams per liter (mg/L), is the amount of BOD.
有機物の量：バクテリアが分解を終えた時、容器内の酸素が半分程度残されている必要があり、推測により希釈する
This might be preferable Should you be sampling underneath adverse problems or if you wish to reduce the time invested accumulating samples. It is additionally somewhat simpler to titrate samples while in the lab, plus much more good quality Management is feasible because the exact man or woman can perform many of the titrations.
Chloride in almost any focus interferes Together with the spectrophotometric analysis of COD. To compensate for this, most test kits demand a pretreatment phase of adding mercury sulfate to precipitate out the chloride.
DO is calculated both in milligrams per liter (mg/L) or "p.c saturation." Milligrams per liter is the quantity of oxygen in a very liter of water. % saturation is the level of oxygen in a liter of water relative to the full volume of oxygen that the water can maintain at that temperature.
Hold the titrator While using the cartridge tip up. Flip the delivery knob to eject air and a few drops of titrant. Reset the counter to 0 and wipe the idea.
Wastewater generated by industrial, industrial and institutional services is often often called "superior-power" when compared to usual website home wastewater.
Measurements which include nitrogenous demand typically will not be practical for examining the oxygen demand linked to natural materials. Nitrogenous demand could be believed straight from ammonia nitrogen, and carbonaceous demand is often estimated by subtracting the theoretical equal in the nitrite and nitrate made in uninhibited test results.
A few samples are employed for this example, but three samples are much too several to work out an exact ratio. It is suggested that at least ten samples be accustomed to produce an Preliminary ratio and which the ratio is continuously up to date based on extra periodic sample results.
試料の溶存酸素量や微生物の種類などによって測定値は影響を受けるため注意が必要である。
Particularly cold water is made up of additional oxygen than particularly heat water. This may lead us to think that winter water includes a substantial amount of oxygen, but this is simply not the case.
具体的な測定器具・手順は規格によって様々だが、時間の掛かる公定法と短時間で結果が出せる簡易法がある。
Water also absorbs oxygen launched by aquatic crops through photosynthesis. Enough DO is crucial to advancement and reproduction of aerobic aquatic get more info lifestyle (e.
Water at decrease temperatures should have a higher focus of dissolved oxygen and an increased %DO, but warmer, more polluted water should have a reduce concentration and %DO.