Atmospheric Dispersion Study of TRS Compounds Emitted from a Pulp Mill Plant in Coastal Regions of the Uruguay River, South America

ORCELLET EMILIANA; BERRI GUILLERMO J.; AGUIRRE CÉSAR; MÜLLER GABRIELA V.

AEROSOL AND AIR QUALITY RESEARCH

TAIWAN ASSOC AEROSOL RES-TAAR

Año: 2015

1680-8584

The atmospheric dispersion of total reduced sulfur (TRS) emissions from the pulp mill plant of Fray Bentos, Uruguay is simulated. The local authorities of the Environmental Monitoring Program (EMP) of Gualeguaychú, Argentina, received social  complaints  of  malodor  presence  in  different  places  of  the  region.  An  atmospheric  dispersion  model  coupled  to  a boundary  layer  forecast  model  is  used  to  simulate  11  events  in  which  the  EMP  officials  attended  the  scene  in  order  to verify  the  situation.  The  validation  of  modeled  winds  with  the  observations  from  a  meteorological  tower  indicates reasonably  accurate  wind  forecasts.  The  spatial  layout  of  the  modeled  TRS  plumes  is  compared  with  the  geographical distribution of points in the area where the social complaints were recorded. Nine of the 11 studied events are successful modeling cases since a positive (negative) in situ verification matches with a plume position over (far from) the site. In one of the two unsuccessful modeling cases, although the plume is marginally distant from the site, the average wind direction error is the largest one of all the events. In the other case the modeled plume is in fact over the site, but the situation was negatively verified. The reason for the disagreement could be the wind direction changes during the event. This was the longest modeled case that  lasted for 7 hours and the plume was meandering during that time; first from SSW to the S, then back  the  SSW,  and  finally  to  the  S  and  SSE.  The  conclusion  of  the  study  is  that,  despite  the  inherent  uncertainty  of numerical  simulations,  the  implemented  modeling  system  shows  versatility  and  proves  to  be  a  useful  tool  not  only  for diagnostic studies but also for preventing conflictive situations since it can produce reasonably accurate forecast of plume position and its potential impact.