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The units MLSS is primarily measured in milligram per litre (mg/L), but for activated sludge its mostly measured in gram per litre [g/L] which is equal to kilogram per cubic metre [kg/m3]. Mixed liquor is a combination of raw or unsettled wastewater or pre-settled wastewater and activated sludge within an aeration tank.
Cancer slope factors (CSF) are used to estimate the risk of cancer associated with exposure to a carcinogenic or potentially carcinogenic substance. A slope factor is an upper bound, approximating a 95% confidence limit, on the increased cancer risk from a lifetime exposure to an agent by ingestion or inhalation.
Cholinesterase inhibition was observed at all dose levels tested, and a NOAEL of 0.03 mg/kg/day estimated by dividing a LOAEL of 0.3 mg/kg/day by an uncertainty factor of 10. As with the acute RfD, the chronic RfD of 3×10 −4 mg/kg/day was determined by dividing this NOAEL by the inter- and intraspecies uncertainty factors.
Total suspended solids (TSS) is the dry-weight of suspended particles, that are not dissolved, in a sample of water that can be trapped by a filter that is analyzed using a filtration apparatus known as sintered glass crucible.
Densities using the following metric units all have exactly the same numerical value, one thousandth of the value in (kg/m 3). Liquid water has a density of about 1 kg/dm 3, making any of these SI units numerically convenient to use as most solids and liquids have densities between 0.1 and 20 kg/dm 3. kilogram per cubic decimetre (kg/dm 3)
Parts-per notations may be expressed in terms of any unit of the same measure. For instance, the expansion coefficient of some brass alloy, α = 18.7 ppm/°C, may be expressed as 18.7 (μm/m)/°C, or as 18.7 (μ in/in)/°C; the numeric value representing a relative proportion does not change with the adoption of a different unit of length.
The botulinum toxin as the most toxic substance known has an LD 50 value of 1 ng/kg, while the most non-toxic substance water has an LD 50 value of more than 90 g/kg; a difference of about 1 in 100 billion, or 11 orders of magnitude. As with all measured values that differ by many orders of magnitude, a logarithmic view is advisable.
The activated sludge process is a type of biological wastewater treatment process for treating sewage or industrial wastewaters using aeration and a biological floc composed of bacteria and protozoa. It is one of several biological wastewater treatment alternatives in secondary treatment , which deals with the removal of biodegradable organic ...