Sewage water quality

SS: solid suspended solids, the general unit mg / L. Generally refers to: filter paper should be filtered water sample, the filtrate after the retentate at 105 ℃ temperature constant weight after drying the solid mass.
COD: chemical oxygen demand, the general unit mg / L. COD determination principle is: With strong oxidant (China's legal use of potassium dichromate), under acidic conditions, the oxidation of organic matter into CO2 and H2O consumed oxygen, known as the chemical oxygen demand. With CODCr, generally expressed as COD. COD Advantages: can more accurately represent the organic content of sewage, measurement time only a few hours, and not affected by water quality. The larger the chemical oxygen demand, the more serious water pollution by organic matter.
BOD: Biochemical oxygen demand, general unit mg / L. Organic pollutants dissolved by microbial decomposition of the amount of dissolved oxygen.
NH3-N: ammonia nitrogen, the general unit mg / L. Ammonia Nitrogen refers to the nitrogen present in the water as free ammonia (NH3) and ammonium ions (NH4 +).
TP: total phosphorus, the general unit mg / L. Sewage phosphorus compounds can be divided into two types of organic phosphorus and inorganic phosphorus.
Coliform bacteria: is the number of coliform bacteria contained in each liter of water samples, to count / L.
The total number of bacteria: is the total number of coliform bacteria, pathogens, viruses and other bacteria in total, expressed as the total number of bacterial colonies per milliliter of water samples.