Question

What is the maximum amount (mg) of hydrogen cyanide gas (HCN), in mg, that can be released instantaneously on the ground to result in a concentration in the adjacent residential area 50 m directly downwind equal to the AEGL-1 30 minutes of 2.5 ppm? Assume rural conditions and worst case conditions. The temperature is 25°C and the barometric pressure is 1 atm pressure. 2.0 mg 5.0 mg 7.7 mg 12.2 mg

Answer 1

Find in' max amt HCN 다. (mg) that on ground is Instant aneously released concentration in residential to result 2.5ppm od som directly downwind arda worst case scenario conditions Anume rural D= latm T= 25°c, instantaneous have with puff Am) Now me level release at ground point source 15 given by (along -axis) 2-a. The i concentration 2 Qm* I L exp (x-ut) C 312 T oxoyoz

ini mg/m3 C- concentration of pollutant released Qmt amount dispersion co-efficients. rary.oz wind (2m/s) velocity of distance Х from reach to taken ti time Origin distance case conditions Now for worst Qm* {c Ta rithe axry og] exp l (a-ut)] اد worst case Qm under For max ntability class. F choose conditions, we

where for Puff dispension model. 0.891 0.61 o x=ry: 0.022 0.050 2 = 50m. y = 0.650m :ox-0.650m mm and o2= 0.5436 m anume u= amis. Now ta som 2 22 => in- الداع .:t=25s to mg/m² c from ppm to convert Now os (T) * C (mg / m²) C(ppm) = 0.08205 ( суу м)

T= temp Piprenure in atm .. 2.58pm -0.08205 (25+273) + C M = mol.wt ing 기 mu I atmx 27.07 g mole m & ul bu ate ca 2.5 * 1 * 22.07 0.08205 (298) * :. Art (2.76*57 76*12* (T)*(0.650)*4(0.5431')] * exp [ 50- 2*25 1 ] ) 6.581 ~ 5 mg Qm 4.99 mg r