From July to August 2022,the temperature in the Sichuan Basin was 3.63℃higher than that of last year,and the number of ozone pollution days increased significantly compared to previous years.To understand the effects of high temperature on biogenic emissions and O3 generation contribution in the Sichuan Basin,the Model of Emissions of Gases and Aerosols from Nature(MEGAN)was used to estimate the emissions of biogenic volatile organic compounds(BVOCs)in the Sichuan Basin from July to August 2022 based on the meteorological data obtained by Weather Research and Forecasting(WRF)simulations.The spatiotemporal distribution characteristics of BVOCs and chemical species were analyzed.The impact of BVOCs emissions on O3 generation in high temperature weather was quantitatively evaluated by a Community Multi-Scale Air Quality(CMAQ)model.The results showed that:(1)From July to August 2022,BVOCs emissions in the Sichuan Basin were 86.30×104 t,and the emissions of isoprene,methanol and monoterpenes were 42.16×104,17.32×104 and 9.92×104 t,respectively.The BVOCs emission intensities of Chengdu Plain urban agglomeration,South Sichuan urban agglomeration,and Northeast Sichuan urban agglomeration were 3.61,6.55 and 5.00 t/km2,respectively.(2)The high emission areas of BVOCs were mainly concentrated in the central parts of Yibin City and Luzhou City in the South Sichuan urban agglomeration,the northeastern part of Leshan City in the Chengdu Plain urban agglomeration,and the northern parts of Bazhong City and Dazhou City in the Northeastern Sichuan urban agglomeration.The spatial distribution characteristics of isoprene and monoterpene emissions were basically consistent with those of BVOCs emissions,while the spatial distribution characteristics of methanol showed significant differences.(3)BVOCs emissions had an obvious diurnal characteristic and the highest emission occurred at 14:00.(4)The CMAQ simulation results showed that the cities with large contributions of BVOCs emissions to O3 generation were Leshan,Meishan,Ya'an,and Neijiang,with contribution rate of over 30%.In terms of spatial distribution,BVOCs emissions in the northern part of Leshan and the central-western parts of Meishan in Chengdu Plain urban agglomeration had the most significant contribution to O3 generation.From July to August 2022,the contribution of BVOCs emissions to O3 generation in high temperature weather was 4.99%higher than that of last year.Based on the above research results,BVOCs emissions in Sichuan Basin has an significant impact on O3 pollution,and the contribution rate to O3 generation further increases in high temperature weather,which is the focus for O3 pollution prevention and control.

为了研究广元市房建施工扬尘排放特征,通过调研获取了广元市2010 ～2019年间的房建工地施工面积、抑尘措施及控制效率,按照自下而上的方法建立了房建施工扬尘排放清单,分析了2019年广元市房建施工扬尘的时空分布特征,并采用CALPUFF对广元市利州区某房建工地的排放进行了模拟.结果 表明:(1) 2010 ～2019年广元市房建施工扬尘排放量逐步增加,PM10和PM2.5的排放量分别从2010年的830.25t和192.99t增加到2019年的2027.26t和471.24t,年均增长率达到10.43％;(2)广元市房建施工扬尘在春季排放最高,其次为冬季和秋季,夏季排放量最小,全市房建扬尘的高排放区为利州区、剑阁县、苍溪县等区域;(3)通过CALPUFF模拟发现,广元市施工扬尘主要向东南方向扩散,对施工区周边600m范围内的区域影响较大.研究认为,广元市房建施工扬尘排污呈现逐年增加趋势,应当进一步加强管控以降低排污.

为了促进四川省钢铁行业产业升级,减少污染物排放量,提高环境空气质量,通过横向和纵向对比分析2015年、2016年四川省环境统计中钢铁行业数据,评估四川省钢铁行业万元产值污染物排放量和单位产品污染物排放量绩效,得到如下结果:2016年四川省钢铁行业(炼铁工段和炼钢工段)二氧化硫、氮氧化物、烟粉尘排放量较2015年排放量分别减少了33.19％、3.15％和37.34％.2016年四川省吨钢二氧化硫排放量、吨钢氮氧化物排放量、吨钢烟粉尘排放量较2015年分别下降27.2％、9.76％、41.61％.整体上看,四川省钢铁行业污染防治水平有所提升,但排放绩效欲达到全国平均水平,仍需分别减排二氧化硫、氮氧化物、烟尘78470.69t、6361.62t、32886.87t."十四五"期间,四川省钢铁行业将面临巨大压力,有组织污染物减排在现有基础上再下降80.0％ ～83.3％.根据四川省钢铁行业污染防治现状,建议优化脱硫除尘设施,提高末端治理效率,提升二氧化硫和颗粒物污染防治绩效水平,普及脱硝设施,加强无组织管控.

采用DustTRAK TM气溶胶(粉尘)监测仪对成都市112个不同类别的房建、市政工地施工扬尘进行测试,研究了不同类别施工扬尘的排放特征,分析了下风向扬尘浓度的变化趋势,并采用CALPUFF对成都市新都区某建筑工地的排放进行了模拟.结果表明:(1)成都市施工扬尘排放浓度约为0.13～2.91mg/m3,其中房建类施工平均浓度约为0.94mg/m3,高于市政施工;大型工地扬尘平均浓度约为0.61mg/m3,低于中型和小型工地;土方施工阶段平均浓度约为1.21mg/m3,远高于地基建设、主体建设、装饰阶段.(2)成都市施工扬尘呈现出高低浓度交替的周期性变化,其中房建工程土方施工阶段的高低浓度差值可达到0.6mg/m3以上.(3)施工扬尘在场界外下风向5～15m范围内会出现浓度增加的趋势,随后逐渐下降,在50m附近逐渐趋于稳定,稳定浓度介于0.1～0.2mg/m3.(4)CALPUFF模型能较好地从宏观角度来模拟成都地区施工扬尘的扩散趋势,但难以捕捉施工扬尘在下风向近距离的扩散特征.