垃圾渗滤液的臭氧处理

由于垃圾渗滤液具有复杂的水质特征,所以垃圾渗滤液的臭氧处理是十分必要的。本文介绍了基于臭氧的垃圾渗滤液处理技术的研究和应用现状,以及臭氧处理单元的发展和先进的臭氧化反应系统。总结了垃圾渗滤液臭氧处理的优缺点,预测了这一技术的发展趋势。     

Control Strategy Optimization for Attainment and Exposure Mitigation: Case Study for Ozone in Macon, Georgia

Implementation of more stringent 8-hour ozone standards has led the U.S. Environmental Protection Agency to designate nonattainment status to 474 counties nationwide, many of which had never previously violated air quality standards. As states select emission control measures to achieve attainment in these regions, their choices pose significant implications to local economies and the health of their citizens. Considering a case study of one such nonattainment region, Macon, Georgia, we develop a menu of potential controls that could be implemented locally or in neighboring parts of the state. The control menu offers the potential to control about 20–35% of ozone precursor emissions in most Georgia regions, but marginal costs increase rapidly beyond 15–20%. We link high-order ozone sensitivities with the control menu to identify cost-optimized strategies for achieving attainment and for alternative goals such as reducing spatially averaged or population-weighted ozone concentrations. Strategies targeted toward attainment of Macon ozone would prioritize local reductions of nitrogen oxides, whereas controls in the more densely populated Atlanta region are shown to be more effective for reducing statewide potential population exposure to ozone. A U.S. EPA-sanctioned approach for demonstrating ozone attainment with photochemical models is shown to be highly dependent on the choice of a baseline period and may not foster optimal strategies for assuring attainment and protecting human health.     

Modeling of spatial and temporal variations of ozone-NOx-VOC sensitivity based on photochemical indicators in China

Comprehensive air quality model with extensions (CAMx)-decoupled direct method (DDM) was used to simulate ozone-NO_x-VOCs sensitivity of for May–November in 2016–2018 in China. Based on the relationship between the simulated ozone (O₃) sensitivity values and the ratio of formaldehyde (HCHO) to NO₂ (FNR) and the ratio of production rate of hydrogen peroxide (H₂O₂) to production rate of nitric acid (HNO₃) ($P_{{\mathrm{H}}_2{\mathrm{O}}_2}/P_{\text{HN}{\mathrm{O}}_3}$), the localized range of FNR and $P_{{\mathrm{H}}_2{\mathrm{O}}_2}/P_{\text{HN}{\mathrm{O}}_3}$ thresholds in different regions in China were obtained. The overall simulated FNR values are about 1.640–2.520, and $P_{{\mathrm{H}}_2{\mathrm{O}}_2}/P_{\text{HN}{\mathrm{O}}_3}$ values are about 0.540–0.830 for the transition regime. Model simulated O₃ sensitivities or region specific FNR or $P_{{\mathrm{H}}_2{\mathrm{O}}_2}/P_{\text{HN}{\mathrm{O}}_3}$ thresholds should be applied to ensure the accurate local O₃ sensitivity regimes. Using the tropospheric column FNR values from ozone monitoring instrument (OMI) satellite data as an indicator with the simulated threshold values, the spatial distributions of O₃ formation regimes in China are determined. The O₃ sensitivity regimes from eastern to central China are gradually from VOC-limited, transition to NO_x-limited spatially, and moving toward to transition or NO_x-limited regime from 2005 to 2019 temporally.     

中山市臭氧污染来源解析与敏感性分析

利用数值天气预报模式和嵌套网格空气质量预报系统的来源解析模块（WRF NAQPMS/OSAM）对中山市2019年9月1次臭氧（O₃）污染过程进行了模拟分析，并对O₃来源进行了解析。结果表明，WRF-NAQPMS/OSAM模型能较好地模拟出该时段的O₃浓度。此次污染过程区域传输对中山市O₃浓度贡献显著，平均贡献比例为82.9%，本地平均贡献比例为17.1%，对中山市O₃贡献最大的2个来源分别是溶剂源和交通源，平均贡献占比分别为43.0%和42.7%。另外，工业源的贡献也不可忽略，平均贡献占比为11.0%。中山市O₃总体上处于挥发性有机物（VOCs）控制区，结合臭氧生成潜势（OFP）分析和源解析结果，溶剂源、交通源和工业源排放的甲苯、间/对二甲苯、邻二甲苯、1，2，3-三甲苯、正丁烷和异戊烷对O₃形成贡献显著，是中山市O₃污染治理应注意的重要前体物。建议中山市建立以VOCs控制为主导，VOCs和氮氧化物（NO_X）协同控制的长期O₃防控策略。     

三维空气质量模型初始场VOCs同化对臭氧预报的影响

于2023年2月15日—3月8日，采用中尺度数值预报模式/嵌套网格空气质量模式系统（WRF/NAQPMS），分析了初始场同化6项常规大气污染物及挥发性有机物（VOCs）对广东省臭氧（O₃）预报的改进效果。 结果表明，同化6项常规污染物可显著降低O₃预报的标准化平均偏差（NMB）和均方根误差（RMSE），NMB从-26%改善为-8%，RMSE从50.6μg/m³下降到35.0μg/m³。但对相关系数（r）的改善效果不佳，从0.51下降到0.49。相比于只同化常规6项污染物，同时同化VOCs对O₃的预报效果改善较为明显，r从0.49提高到0.63。此外，对NMB和RMSE的改善效果也较好，NMB从-8%改善为-3%，RMSE从35.0μg/m³下降到30.1μg/m³。相比于不同化，同化6项常规污染物的改善效果显著，空气质量指数（AQI）等级预报准确率可提升10%以上，AQI范围预报准确率可提升40%以上。相比于仅同化6项常规污染物，再增加同化VOCs，AQI等级预报准确率和范围预报准确率均提升5%左右，改善程度不高。     

济南市夏季甲醛时空分布特征及对臭氧污染的影响

基于Sentinel-5P卫星遥感数据,分析济南市2019—2021年夏季甲醛浓度的时空分布特征及对臭氧污染的影响。结果表明：研究期间夏季甲醛平均柱浓度呈逐年下降趋势,2020年同比降幅最大为24%;甲醛浓度高值区域主要分布在人口密集的市区及工业聚集的章丘区、济阳区和商河县,呈现由城市中心向外扩散的趋势;甲醛浓度受周边城市的影响,形成一条东西向的区域化污染带;甲醛对臭氧的影响主要表现在臭氧污染轻度或污染初期,而氮氧化物的排放进一步加重臭氧污染。     

佛山市近地面臭氧污染特征及相关气象因子分析

利用2014年佛山市8个国控大气自动监测点位的O_3监测数据,分析了佛山市的O_3污染特征,结果表明,2014年O_3日最大8 h平均值的第90百分位数为167μg/m~3,O_3为首要污染物的超标天数为43d,占比46.7%;ρ(O_3)区域变化不大;ρ(O_3)月变化呈现"三峰型",全年高ρ(O_3)集中在6—10月份,其中7月份出现全年最高峰值;ρ(O_3)日变化呈单峰型分布,夜间浓度较低且变化平缓,14:00—16:00左右达到峰值,并存在一定的"周末效应",但并不明显;ρ(O_3)与气温呈显著正相关,与湿度、气压、雨量呈显著负相关,与风向、风速的相关性相对较弱;总体上看,高温、低湿、微风、偏南风、低压、无雨的天气条件下高ρ(O_3)更容易出现。