Response of organic aerosol characteristics to emission reduction in Yangtze River Delta region

● The emission reduction causes significant change in organic aerosol composition. ● The atmospheric oxidizing capacity improved during emission reduction. ● The mixed oxygenated organic aerosol contributed higher during emission reduction. Organic aerosol (OA) is a major component of atmospheric particulate matter (PM) with complex composition and formation processes influenced by various factors. Emission reduction can alter both precursors and oxidants which further affects secondary OA formation. Here we provide an observational analysis of secondary OA (SOA) variation properties in Yangtze River Delta (YRD) of eastern China in response to large scale of emission reduction during Chinese New Year (CNY) holidays from 2015 to 2020, and the COVID-19 pandemic period from January to March, 2020. We found a 17% increase of SOA proportion during the COVID lockdown. The relative enrichment of SOA is also found during multi-year CNY holidays with dramatic reduction of anthropogenic emissions. Two types of oxygenated OA (OOA) influenced by mixed emissions and SOA formation were found to be the dominant components during the lockdown in YRD region. Our results highlight that these emission-reduction-induced changes in organic aerosol need to be considered in the future to optimize air pollution control measures.     

微波/活性炭/双氧水协同降解甲基红废水的研究

对微波/活性炭/双氧水联合降解甲基红染料废水进行了研究。考察了活性炭量、双氧水量、甲基红初始浓度、微波功率、pH以及处理时间等因素对甲基红降解效果的影响。结果表明,对于100 mL 100 mg/L甲基红溶液,当加入0.5 g活性炭,1 mL 30%H₂O₂,调节微波功率至680 W,反应25 min后,甲基红降解率达到81.87%。通过对比试验,发现微波、活性炭及双氧水对甲基红的降解起协同作用。     

评定环境工程中标方案的AHP模型及应用

建立了评定环境工程中标方案的层次分析模型（以下简称ＡＨＰ）。对定性因素按１￣９标度构造判断矩阵；对定量因素则采用一定的数学变换，将量化值转化为判断矩阵。ＡＨＰ方法已成功地应用于某废水治理工程项目的评标工作。     

Effect of liming on sulfate transformation and sulfur gas emissions in degraded vegetable soil treated by reductive soil disinfestation

Reductive soil disinfestation (RSD), namely amending organic materials and mulching or flooding to create strong reductive status, has been widely applied to improve degraded soils. However, there is little information available about sulfate (SO₄^2 −) transformation and sulfur (S) gas emissions during RSD treatment to degraded vegetable soils, in which S is generally accumulated. To investigate the effects of liming on SO₄^2 − transformation and S gas emissions, two SO₄^2 −-accumulated vegetable soils (denoted as S1 and S2) were treated by RSD, and RSD plus lime, denoted as RSD₀ and RSD₁, respectively. The results showed that RSD₀ treatment reduced soil SO₄^2 − by 51% and 61% in S1 and S2, respectively. The disappeared SO₄^2 − was mainly transformed into the undissolved form. During RSD treatment, hydrogen sulfide (H₂S), carbonyl sulfide (COS), and dimethyl sulfide (DMS) were detected, but the total S gas emission accounted for < 0.006% of total S in both soils. Compared to RSD₀, lime addition stimulated the conversion of SO₄^2 − into undissolved form, reduced soil SO₄^2 − by 81% in S1 and 84% in S2 and reduced total S gas emissions by 32% in S1 and 57% in S2, respectively. In addition to H₂S, COS and DMS, the emissions of carbon disulfide, methyl mercaptan, and dimethyl disulfide were also detected in RSD₁ treatment. The results indicated that RSD was an effective method to remove SO₄^2 −, liming stimulates the conversion of dissolved SO₄^2 − into undissolved form, probably due to the precipitation with calcium.     

管内普速旅客列车餐车食品经营现状与对策

对管内56个餐车班组2018-2019年食品安全状况进行调查与分析,结果显示贮存运输、设施设备、后厨卫生3个方面的问题较为突出,提示卫生监督部门应重点加强普速列车餐车的专业指导及监督检查.从规范餐车食品经营、强化岗前食品安全知识培训、严格餐车外包经营资格准入及加强餐车食品安全日常管理等方面提出加强普速旅客列车餐车食品经...     

碳源及水力负荷对渗滤系统污水处理效果影响

农村污水能否有效处理是影响农村经济生态发展的关键问题,地下渗滤系统能有效处理农村污水并在实际中得到广泛运用,但其存在可承受的水力负荷较低、脱氮效果不理想的问题。为提高系统的抗冲击负荷性能及脱氮效果,文章选用不同物化性质的填料对地下渗滤系统进行改良,对改良地下渗滤系统中COD、TP、NH_4~+-N、TN的去除效果进行分析,研究不同补充碳源、不同水力负荷、不同改良填料对系统脱氮效果的影响。结果表明:葡萄糖为碳源时对COD、TP、TN平均去除率更高;在系统可抗冲击负荷范围内,提高水力负荷能增强系统的脱氮效果;在改良系统中添加生物基质能在不影响其他污染物去除的情况下,同时增强系统的抗冲击负荷能力和脱氮效果。     

山东枣庄熊耳山崩塌遗迹成因初探

通过实地考察和分析,结合历史地震记载资料,对熊耳山地貌、裂谷以及崩塌遗迹的形成原因进行了初步探讨。初步认为,熊耳山裂谷及崩塌是1668年郯城81/2级地震的产物,属典型的地震灾害遗迹。     

宁波农村地区典型村镇河流污染现状及控制策略

根据2008年10月-2009年9月宁波农村地区典型村镇河流的现场水质指标、各态氮磷和有机物浓度的周年监测结果,对村镇河流的水体污染现状进行全面分析。结果表明：（1）从现场水质指标看,村镇河流的水温和pH指标相对正常,溶解氧浓度受河流有机污染和水体富营养化影响,伴随日照强度呈现大小畀端的现象,河流水质浊度总体较高且与地表径流存在较高相关性;（2）村镇河流呈现NO3^--N低NH4^＋—N高的氮污染特征,可溶态氮磷占TN、TP比例较高。分另4为80．4％和59．1％;（3）村镇河流氮磷和有机物污豢均较严重,NH4^＋-N、TP、CODMa指标已有92．7％、65．6％和32．3％的时间断面属劣V类水质,枯水期是村镇河流污染最严重的时期。     

太湖典型入湖河道中氨氮去除研究

入湖河流是湖泊营养物质的一个重要来源,因此入湖河道水质的改善是控制湖泊富营养化的关键。文章采用自行研制的新型仿生填料直接布设在河道内的生物接触氧化法,在不影响河流生态结构和原有使用功能的前提下,对河流微污染水体进行氨氮的去除研究。研究结果显示,氨氮的净去除率在5.35%~39.91%,其中最高为7月的39.91%,最低月为12月的5.35%。试验期间生物膜的平均厚度为0.8~1.1mm(雨后略厚),生物膜内的微生物主要是一些贫营养微生物,数量少,因此形成的生物膜较薄,生物膜由表及里几乎全是好气层。同时,根据氨氮去除率与硝化菌的数量关系也可以看出试验河段内氨氮的去除主要是靠硝化菌的硝化作用来完成的。