The biological oxygen demand test procedure Diaries
The biological oxygen demand test procedure Diaries
Blog Article
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
Color: The color of water that is definitely lower in oxygen may well alter from mild inexperienced to pea-soup inexperienced, brown, grey or black. Darkish sediments due to metallic sulfides point out anoxic conditions.
This implies considerably less oxygen is obtainable to better varieties of aquatic lifetime. The results of high BOD are similar to Individuals for very low dissolved oxygen: aquatic organisms turn into stressed, suffocate, and die.
Distilled and deionized water are generally Utilized in BOD testing. Having said that, one of the most sensible method to constantly generate water of minimal organic content material is by distillation with alkaline permanganate.
Nutrients: Significant nutrients may result in too much plant growth, resulting in DO declines resulting from respiration and decomposition.
The wastewater/extraction chemical levels are permitted to independent in the funnel (the lighter water layer will be on the very best and heavier extraction chemical layer will be on the bottom). The bottom layer of extraction chemical is drained to the flask organized get more info in Step 1.
An extended UBOD (supreme BOD) test that steps oxygen consumption right after 60 times or even more is sometimes necessary in wastewater permits.
Resources of biochemical oxygen demand incorporate topsoil, leaves and woody particles; animal manure; effluents from pulp and paper mills, wastewater cure plants, feedlots, and food stuff-processing vegetation; failing septic systems; and urban stormwater runoff.
The usage of soda lime as opposed to calcium hydroxide is suggested mainly because soda lime presents better absorption potential in this more info software and in addition helps prevent condensing water vapors from dripping back again into the solution. This seemingly small characteristic was observed to boost measurement accuracy.
Use the meter to measure the water temperature and file it in the water temperature column on the field data sheet.
BOD is calculated in sewage therapy or wastewater therapy to discover the destruction of natural and organic wastes by aerobic microbes
阻害物質：バクテリアの活動や増殖を妨げる酸やアルカリ、重金属や殺菌剤など毒性のある物質が含まれている場合、前処理や耐性のあるバクテリアの馴養が必要
Documentation of DO concentrations in excess of a 24-hour period of time might be handy for identifying diurnal designs and could expose information regarding DO depletion.
This happens usually in lakes which were stocked with fish and lakes that obtain sewage inputs.