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For example, such a regulation might limit the concentration of NOx to 55 ppmv in a dry combustion exhaust gas corrected to 3 volume percent O 2. As another example, a regulation might limit the concentration of particulate matter to 0.1 grain per standard cubic foot (i.e., scf) of dry exhaust gas corrected to 12 volume percent CO 2.
As another example, a regulation might limit the concentration of total particulate matter to 200 mg/m 3 of an emitted gas (at a specified reference temperature and pressure) corrected to a dry basis and further corrected to 12 volume percent CO 2 in the dry gas.
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.
For methylmercury, the US Environmental Protection Agency (US EPA) has estimated a safe daily intake level of 0.1 μg/kg body weight per day. [ 19 ] The National Institute for Occupational Safety and Health (NIOSH) recommends that exposures to mercury metal be limited to an average of 0.05 mg/m 3 over a 10-hour workday in addition to a ceiling ...
cubic foot per day: cubic feet per day: m3/d: Cubic foot per second: cuft/h: cu ft/h: 28316846592e-12/3600: cubic foot per hour: cubic feet per hour: m3/h: Cubic foot per second: cuft/min: cu ft/min: 28316846592e-12/60: cubic foot per minute: cubic feet per minute: m3/min: Cubic foot per minute: cuft/s: cu ft/s: 28316846592e-12: cubic foot per ...
Subsequently, the National Academy of Sciences (NAS) reviewed the health implications of perchlorate, and in 2005 proposed a much higher alternative reference dose of 0.0007 mg/kg/day based primarily on a 2002 study by Greer et al. [6] During that study, 37 adult human subjects were split into four exposure groups exposed to 0.007 (7 subjects ...
The U.S. Public Health Service published a non-enforceable standard for lead in 1925, consisting of a tolerance limit of 0.1 mg/L. [6] [7] Partially because of the continued use of lead pipes, some states regulated the corrosivity of treated water put into the distribution system. Waters which would deposit a protective coating on the pipes ...
For example, the conversion factor between a mass fraction of 1 ppb and a mole fraction of 1 ppb is about 4.7 for the greenhouse gas CFC-11 in air (Molar mass of CFC-11 / Mean molar mass of air = 137.368 / 28.97 = 4.74). For volume fraction, the suffix "V" or "v" is sometimes appended to the parts-per notation (e.g. ppmV, ppbv, pptv).