应用ARPS-CMAQ模拟研究石景山污染对北京的影响

建立了中尺度气象模型ARPS与区域多尺度空气质量模型CMAQ的耦合模型系统,应用该模型系统模拟研究了2002年1月份和8月份石景山区污染物排放对北京市空气质量的影响.模拟结果显示,1、8两个月份石景山区污染对北京市PM10的月均贡献浓度分别为29.68μg·m-3和32.09μg·m-3,其中污染较重日的日均贡献浓度在50μg·m-3左右,说明石景山污染对北京市空气质量影响较大.同时,进一步对两月典型污染过程进行深入分析,研究发现,在所选两个污染过程中,石景山对北京PM10的贡献浓度与监测浓度同步升高或降低.首先,在污染过程的前期,石景山贡献浓度较低且变化不大,之后贡献浓度与监测浓度同步快速上升,该阶段贡献浓度增量对监测浓度增量的贡献较大,分别占到了同期各自监测浓度增量的52.89%和44.78%,最后,贡献浓度与监测浓度同步降低,说明,在所选污染过程中贡献浓度短时间内的迅速增加是导致北京市监测浓度骤然升高的一个重要原因.     

Characterizing ozone pollution in a petrochemical industrial area in Beijing,China: a case study using a chemical reaction model

This study selected a petrochemical industrial complex in Beijing, China, to understand the characteristics of surface ozone (O₃) in this industrial area through the on-site measurement campaign during the July–August of 2010 and 2011, and to reveal the response of local O₃ to its precursors’ emissions through the NCAR-Master Mechanism model (NCAR-MM) simulation. Measurement results showed that the O₃ concentration in this industrial area was significantly higher, with the mean daily average of 124.6 μg/m³ and mean daily maximum of 236.8 μg/m³, which are, respectively, 90.9 and 50.6 % higher than those in Beijing urban area. Moreover, the diurnal O₃ peak generally started up early in 11:00–12:00 and usually remained for 5–6 h, greatly different with the normal diurnal pattern of urban O₃. Then, we used NCAR-MM to simulate the average diurnal variation of photochemical O₃ in sunny days of August 2010 in both industrial and urban areas. A good agreement in O₃ diurnal variation pattern and in O₃ relative level was obtained for both areas. For example of O₃ daily maximum, the calculated value in the industrial area was about 51 % higher than in the urban area, while measured value in the industrial area was approximately 60 % higher than in the urban area. Finally, the sensitivity analysis of photochemical O₃ to its precursors was conducted based on a set of VOCs/NOx emissions cases. Simulation results implied that in the industrial area, the response of O₃ to VOCs was negative and to NOx was positive under the current conditions, with the sensitivity coefficients of ?0.16~?0.43 and +0.04~+0.06, respectively. By contrast, the urban area was within the VOCs-limitation regime, where ozone enhancement in response to increasing VOCs emissions and to decreasing NOx emission. So, we think that the VOCs emissions control for this petrochemical industrial complex will increase the potential risk of local ozone pollution aggravation, but will be helpful to inhibit the ozone formation in Beijing urban area through reducing the VOCs transport from the industrial area to the urban area.     

Use of a MM5–CAMx–PSAT Modeling System to Study SO2 Source Apportionment in the Beijing Metropolitan Region

A coupled MM5–CAMx air quality modeling system was used to simulate SO₂ concentrations in Beijing, China during the heating season. Particulate matter source apportionment technology was employed to investigate the apportionment of SO₂ sources in the study area. Comprehensive analysis of the industry and region revealed that the most important SO₂ contributors were publicly and privately supplied heating emission sources and other industry emission sources from the urban areas of Beijing, with 66.1?% of the emission source contribution ratio. Four SO₂ emission reduction scenarios based on our SO₂ source apportionment research were established to assess the potential for improving the SO₂ air quality in Beijing during the heating season. By weighing the desired SO₂ improvement, the availability of technology, and economic considerations, a suitable SO₂ reduction plan was able to be recommended for Beijing city.     

铁屑过滤+H2O2预处理难降解染料废水的研究

介绍了铁屑过滤+H2O2预处理难降解染料废水实验研究结果.采用铁屑过滤微电解法预处理难降解染料废水,当进水pH为4,停留时间为8 min时,出水BOD5/COD较原水提高0.2-0.3;若在铁屑过滤进水中加入H2O2(30%)8‰投加量,可使废水可生化性得到显著改善,有利于后续采用生化法处理.     

生物反应器填埋场产甲烷规律的模拟研究

生物反应器填埋场是一种新型的垃圾卫生填埋场，可以加速填埋场的稳定及甲烷的产生。通过模拟试验探讨了生物反应器填埋场在不同操作条件下的产甲烷情况及COD、pH值的变化趋势。试验证明较高的回灌频率有助于垃圾降解、产甲烷速率的升高及渗滤液中COD浓度的降低；污泥接种起缓冲作用，使垃圾的降解及产气速率更趋向平稳；甲烷的产生与COD的降低是同步进行的，因此可以通过COD的变化趋势来判断产甲烷情况。研究建立了反映垃圾含水率影响填埋场产甲烷的数学模型，该模型具有简便、直观、准确等优点。     

北京、石家庄2017—2018年PM2.5与SNA组分特征及典型重污染分析

基于北京、石家庄2017、2018年的1月和7月PM_2.5样品采集,研究两地采暖期、非采暖期及典型重污染过程的PM_2.5、SNA污染特征及二次转化特征.应用TrajStat模型,结合浓度权重轨迹分析法（CWT）,分析两地PM_2.5气流输送路径以及潜在源区.利用WRF-CAMx模式定量分析两地重污染月份（2017年1月）PM_2.5、硫酸盐及硝酸盐的区域传输贡献.结果表明, 2017年1月北京和石家庄均存在重污染过程,两年1月石家庄市PM_2.5浓度均高于北京; SNA占PM_2.5所有组分的34.11%~51.68%,对PM_2.5浓度有重要贡献,其中北京NO₃^-浓度最高,石家庄SO₄^2-浓度最高, SO₄^2-/NO₃^-夏季高于冬季;北京SOR高于石家庄,石家庄NOR高于北京,重污染期间两城市硫酸盐、硝酸盐、铵盐质量浓度、SOR与NOR明显升高;两地冬季气流主要受俄罗斯、蒙古、内蒙戈壁等地区的西北方向远距离输送影响,另外北京两年冬季均存在西南传输通道,石家庄重污染期间受冀南和鲁西北重工业城市群潜在贡献较高,两市夏季受东南季风影响,污染轨迹多来自渤海湾和山东等地区; 2017年1月,北京、石家庄PM_2.5受周边区域传输贡献分别为33.80%、22.54%,其中河北南部分别贡献14.86%, 17.21%,二次离子中NO₃^-的传输作用比SO₄^2-更加突出.从PM_2.5本地源来看,北京主要来源为移动源和扬尘源,分别占比43.30%、20.10%,石家庄为工业、燃煤和扬尘,分别占比26.40%、24.82%、22.50%.     

A framework for investigating the air quality variation characteristics based on the monitoring data: Case study for Beijing during 2013–2016

In this study, an analysis framework based on the regular monitoring data was proposed for investigating the annual/inter-annual air quality variation and the contributions from different factors(i.e., seasons, pollution periods and airflow directions), through a case study in Beijing from 2013 to 2016. The results showed that the annual mean concentrations(MC) of PM_(2.5), SO_2, NO_2 and CO had decreased with annual mean ratios of 7.5%, 28.6%, 4.6%and 15.5% from 2013 to 2016, respectively. Among seasons, the MC in winter contributed the largest fractions(25.8%～46.4%) to the annual MC, and the change of MC in summer contributed most to the inter-annual MC variation(IMCV) of PM_(2.5) and NO2. For different pollution periods, gradually increase of frequency of S-1(PM_(2.5), 0～ 75 μg/m~3) made S-1 become the largest contributor(28.8%) to the MC of PM_(2.5) in 2016, it had a negative contribution(-13.1%) to the IMCV of PM_(2.5); obvious decreases of frequencies of heavily polluted and severely polluted dominated(44.7% and 39.5%) the IMCV of PM_(2.5). For different airflow directions, the MC of pollutants under the south airflow had the most significant decrease(22.5%～62.5%), and those decrease contributed most to the IMCV of PM_(2.5)(143.3%),SO2(72.0%), NO_2(55.5%) and CO(190.3%); the west airflow had negative influences to the IMCV of PM_(2.5), NO_2 and CO. The framework is helpful for further analysis and utilization of the large amounts of monitoring data; and the analysis results can provide scientific supports for the formulation or adjustment of further air pollution mitigation policy.     

纤维与石英砂过滤技术的比较研究

提出了无需额外反冲洗装置与动力消耗的水力自清洗纤维过滤技术,与石英砂过滤进行了比较研究,探索该技术应用的可行性。结果表明,10 m/h滤速下纤维过滤与石英砂过滤相比,出水浊度、SS分别降低59%和86%,COD、TOC、TP和TN降低5%～20%,水头损失大幅降低,两者初始水头损失分别为0.12 kPa和3.97 kPa,5 h后分别达到1.58kPa和5.98 kPa。纤维滤柱反冲洗历时40 s,而石英砂滤柱为15 min,反洗耗水率分别为2.9%和6.9%。反洗后纤维滤柱出水浊度和SS分别为4.08 NTU、6 mg/L,低于石英砂滤柱的5.81 NTU、28 mg/L。水力自清洗纤维过滤技术可节省动力装置和动力消耗,反冲洗历时短、耗水率低,具有较好的应用前景。     

SBR法处理印染废水的研究

应用ＳＢＲ法、ＰＡＣ－ＳＢＲ法，微电解－ＳＢＲ法对印染废水进行了对比处理试验研究。试验结果表明：微电解－ＳＢＲ法处理效果优于其它两种方法，当进水ＣＯＤ＝１０００～１６００ｍｇ／Ｌ，色度＝２００～８００倍，ＢＯＤ５＝２５０～４００ｍｇ／Ｌ时．ＣＯＤ去除率在８５％左右，ＢＯＤ５去除率和脱色率均在９０％以上，出水达到排放标准。