| In recent years,the demand for chemical fiber products such as viscose fiber is increasing,bringing huge economic benefits and facing severe odor pollution problems.The regional atmospheric environment is deteriorating,causing serious threats and damage to human health and ecological environment.In this study,a cotton-fiber industry in Manas was taken as the research object,and surrounding 5 km rectangular area was selected as the research area.Through routine data collection,H2S,CS2 sample collection and meteorological data observation,H2S,CS2 pollution sources and emission characteristics were discussed,and correlation between H2S,CS2 concentration in surrounding area and those in pollution sources,meteorological factors,topographical factors were revealed.Based on AERMOD model,the distribution characteristics of H2S,CS2 were predicted,and the fit was tested.These provide a theoretical basis for cause and prevention of odor pollution in cotton-fiber industry.The main findings are as follows:(1)In cotton-fiber industry,organized point source H2S,CS2 emission concentration are significantly higher than that of unorganized surface sources.In the organized point source,the maximum emission rates of H2S,CS2 are 0.76 kg·h-1 and 84.54 kg·h-1,all of which do not exceeded.In the unorganized surface sources,H2S,CS2 emission concentration of sewage station(U5)are the highest,being 1.69 mg·m-3 and 5.91 mg·m-3,respectively.In the industry boundary,the maximum hourly concentration of H2S,CS2 are 0.11 mg·m-3 and 0.32 mg·m-3,appearing on the north side of industry boundary(B4).Among them,H2S exceeds 4%;CS2 does not exceed.In the sensitive area,the maximum concentration of H2S is 7 ?g·m-3,not exceed;the maximum concentration of CS2 is 45 ?g·m-3,appearing in the Xia Gobi village(S3),and exceeding 1%.(2)H2S,CS2 emission concentration have no obvious seasonal variation characteristics in the organized point source,but their concentrations in the unorganized surface sources show high in summer and low in winter.The seasonal variation of H2S,CS2 pollution in the industry boundary are characterized by severe odor pollution in winter,followed by spring and autumn,and low pollution in summer.(3)The diurnal variation characteristics of organized point source H2S,CS2 emissions are relatively stable.But unorganized surfaces H2S,CS2 emissions are fluctuating,related to equipment containment,intermittent reaction and other phenomena of running,rushing,dripping and leaking.In the industry boundary,H2S,CS2 concentration are U-shaped and M-shaped,characterized by diurnal variation of "two peaks and one valley".The high incidence of odor pollution in the daytime is mostly from 10:00 to 12:00 am and 20:00 in the evening,but the second peak in winter is slightly ahead of 18:00 in the afternoon.Therefore,odor pollution has obvious time-course characteristics.(4)The prediction results of AERMOD model show that H2S,CS2 concentration are mostly concentrated on the north side of industry boundary(B4).Pollutants in cotton-fiber industry are distributed in a strip shape due to interference of unorganized source emissions.CS2 concentration in surrounding area is mostly concentrated on Xia Gobi village(S3)in the downwind,and fan-shaped distribution is affected by the dominant wind direction(SW)in spring,summer and autumn.Through the verification of predicted and measured concentration,the model fit is poor,predicted concentration is more conservative,and there is a big difference between them.The major reasons are no superimposed environmental background concentration,pollution sources interference of other industries,sampling operation error.and many more.(5)The emission intensity,meteorological factors,and topographic factors are main factors affecting regional atmospheric environment.Based on correlation between H2S,CS2 concentration in surrounding area and pollution sources,unorganized source emission is the main source of odor pollution in industry boundary and near cotton-fiber industry,and organized source emission is the main source affecting surrounding area odor pollution.Based on correlation and relative contribution rate between H2S,CS2 concentration in surrounding area and meteorological factors,temperature,pressure,relative humidity and wind speed are the main reasons affecting odor pollution. |
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