Singh R K, Agrawal M
Department of Botany, Banaras Hindu University, Varanasi, India.
ScientificWorldJournal. 2001 Dec 19;1 Suppl 2:266-74. doi: 10.1100/tsw.2001.388.
An atmospheric deposition study was conducted in the downwind of Shaktinagar Thermal Power Plant (STPP), Renusagar Thermal Power Plant (RTPP), and Anpara Thermal Power Plant (ATPP), at Singrauli region, Uttar Pradesh (UP), India to characterize dry and wet deposition in relation to different pollution loading. During the study period, dry and wet depositions and levels of gaseous pollutants (SO2 and NO2) were estimated across the sites. Dry deposition was collected on a monthly basis and wet deposition on an event basis. Depositions were analyzed for pH, nitrate (NO3-), ammonium (NH4+), and sulphate (SO4(2-)) contents. Dry deposition rate both collected as clearfall and throughfall varied between 0.15 to 2.28 and 0.33 to 3.48 g m(-2) day(-1), respectively, at control and maximally polluted sites. The pH of dry deposition varied from 5.81 to 6.89 during winter and 6.09 to 7.02 during summer across the sites. During the rainy season, the mean pH of clear wet deposition varied from 6.56 to 7.04 and throughfall varied from 6.81 to 7.22. The concentrations of NO2 and SO2 pollutants were highest during the winter season. Mean SO2 concentrations varied from 18 to 75 g m(-3) at control and differently polluted sites during the winter season. The variation in NO2 concentrations did not show a pattern similar to that of SO2. The highest NO2 concentration during the winter season was 50 g m(-3), observed near RTPP. NO2 concentration did not show much variation among different sites, suggesting that the sources of NO2 emission are evenly distributed along the sites. The concentrations of NH4+, NO3-, and SO4(2-) ions in dry deposition were found to be higher in summer as compared to the winter season. In dry deposition (clearfall) the concentrations of NH4+, NO3-, and SO4(2-) varied from 0.13 to 1.0, 0.81 to 1.95, and 0.82 to 3.27 mg l(-1), respectively, during winter. In wet deposition (clearfall), the above varied from 0.14 to 0.74, 0.81 to 1.82, and 0.67 to 2.70 mg l(-1), respectively. The study clearly showed that both dry and wet depositions varied between the sites and season, suggesting significant impact of industrial activities in modifying the atmospheric input. The nonacidic deposition suggests that there is no threat of acidification of the receiving ecosystem at present.
在印度北方邦辛格拉uli地区的沙克蒂纳加尔热电厂（STPP）、雷努萨加尔热电厂（RTPP）和安帕拉热电厂（ATPP）的下风向进行了一项大气沉降研究，以表征与不同污染负荷相关的干沉降和湿沉降。在研究期间，对各站点的干沉降、湿沉降和气态污染物（SO₂和NO₂）水平进行了估算。干沉降每月收集一次，湿沉降按事件收集。对沉降物的pH值、硝酸盐（NO₃⁻）、铵（NH₄⁺）和硫酸盐（SO₄²⁻）含量进行了分析。在对照站点和污染最严重的站点，以林冠截留和穿透雨形式收集的干沉降速率分别在0.15至2.28和0.33至3.48 g m⁻²天⁻¹之间。各站点冬季干沉降的pH值在5.81至6.89之间，夏季在6.09至7.02之间。雨季期间，林冠截留湿沉降的平均pH值在6.56至7.04之间，穿透雨的pH值在6.81至7.22之间。冬季气态污染物NO₂和SO₂的浓度最高。冬季对照站点和不同污染程度站点的SO₂平均浓度在18至75 g m⁻³之间。NO₂浓度的变化模式与SO₂不同。冬季在RTPP附近观测到的NO₂最高浓度为50 g m⁻³。不同站点之间NO₂浓度变化不大，表明NO₂排放源在各站点分布均匀。发现夏季干沉降中NH₄⁺、NO₃⁻和SO₄²⁻离子的浓度高于冬季。冬季干沉降（林冠截留）中NH₄⁺、NO₃⁻和SO₄²⁻的浓度分别在0.13至1.0、0.81至1.95和0.82至3.27 mg l⁻¹之间。湿沉降（林冠截留）中上述离子的浓度分别在0.14至0.74、0.81至1.82和0.67至2.70 mg l⁻¹之间。该研究清楚地表明，干沉降和湿沉降在不同站点和季节之间存在差异，表明工业活动对改变大气输入有重大影响。非酸性沉降表明目前接收生态系统不存在酸化威胁。
