天津市基于新标准的空气质量预报模型效果评估

利用2015年环境空气质量监测数据,对天津市OPAQ空气质量统计预报模型预测效果进行验证评估。结果表明,模型对天津市AQI和PM_(2.5)、PM_(10)、O_3、NO——2的预测结果与实测结果具有较好的趋势一致性,且预测时间越临近,拟合度越好,24 h预报的相关系数r全部达到0.8以上。对PM_(2.5)的预报性能明显优于PM_(10)、O_3和NO_2,PM_(2.5)平均值预测略呈正偏差,但重污染预测值偏低约15%;O_3和NO_2预测值呈明显负偏差,O_3峰值预测不足,NO_2预测值整体偏低,均以24 h预报趋势性最好,但负偏差最为突出。     

中国大气超级站发展与展望：基于问卷调研的统计研究

大气环境综合观测研究站(简称大气超级站)是开展大气环境污染综合立体观测、进行大气重污染过程污染特征动态表征、深入分析大气污染成因的重要平台。了解中国当前不同地区大气超级站的建设和应用现状、存在的问题及发展需求,有利于科学指导和规范中国大气超级站的设计、建设、运维和应用,提高其在大气重污染过程应急管控和空气质量改善中的技术支撑能力。研究通过对国内60余个大气超级站进行问卷调研,综述了中国目前大气超级站的现状,并基于统计分析结果,对中国大气超级站发展提出建议。     

环境中苯并(a)芘监测技术及建议

环境中BaP是引起人们各类癌症的主要诱发物.叙述了环境中BaP的来源及其浓度状况,列举了国家制定的各项标准中的BaP含量的浓度限值,论述了环境水中和空气中BaP的样品采集、保存、前处理、分析测定及定量监测中应注意的几个问题,提出了监测BaP的4点建议.     

Seasonal variation of polycyclic aromatic hydrocarbons in soil and air of Dalian areas, China: an assessment of soil-air exchange

The seasonal variations of concentrations of PAHs in the soil and the air were measured in urban and rural region of Dalian, China in 2007. In soil, mean concentrations of all PAHs in summer were larger than those in winter, whereas the concentrations of heavier weight PAHs in winter were larger than those in summer. Winter/summer concentration ratios for individual PAHs (R(W/S)) increased with the increase of molecular weight of PAHs in soil, indicating that PAHs with high molecular weight were more easily deposited to soil in winter than summer. In air, mean concentrations of all PAHs in winter were larger than those in summer. In comparison with the R(W/S) in soil, all the values of R(W/S) in air were larger than one indicating that the entire individual PAH concentrations in winter were larger than those in summer. The average concentration composition for each PAH compound in soil and air samples was determined and the seasonal change of PAH profile was very small. It was suggested that PAHs in soils and air had the same or similar sources both in winter and summer. The approach to the soil-air equilibrium was assessed by calculating fugacity quotients between soil and air using the soil and air concentrations. The calculated soil-air fugacity quotients indicated that soil acted as a secondary source to the atmosphere for all lighter weight PAHs (two-three rings) and it will continue to be a sink for heavier weight PAHs (five-six rings) in the Dalian environment, both in winter and summer. Medium weight PAHs (four-five rings) were close to the soil-air equilibrium and the tendency shifted between soil and air when season or function region changed. The fugacity quotients of PAHs in summer (mean temperature 298 K) were larger than those in winter (mean temperature 273 K), indicating a higher tendency in summer than winter for PAHs to move from soil to air. The variation of ambient conditions such as temperature, rainfall, etc. can influence the movement of PAHs between soil and air. Most of the fugacity quotients of PAHs for the urban sites were larger than that for the rural site both in winter and summer. This phenomenon may be related with that the temperatures in urban sites were higher than those in the rural site because of the urban heat island effect.     

重金属光谱分析仪与原子吸收光谱测定土壤中的重金属

采用重金属光谱分析仪与原子吸收光谱测定土壤中的Cr、Cu、Ni、Pb、Zn和As六种金属,结果发现,重金属光谱分析仪对Cu、Pb、Zn和As四种金属的检测结果较为理想,与原子吸收光谱的检测数据接近,误差可满足现场检测的要求.重金属光谱分析仪测定方法简便,操作简单,省时省力,可满足大部分重金属检测的要求.     

Effects of pig manure containing copper and zinc on microbial community assessed via phospholipids in soils

Pig manure (PM) is widely used as an organic fertilizer to increase yields of crops. Excessive application of compost containing relatively great concentrations of copper (Cu) and zinc (Zn) can change soil quality. To clarify the effects of different rates of application and to determine the optimal rate of fertilization, PM containing 1,115 mg Cu kg^?1, dry mass (dm) and 1,497 mg Zn kg^?1, dm was applied to alkaline soil at rates of 0, 11, 22, 44, 88, and 222 g PM kg^?1, dm. Phospholipid fatty acids (PLFAs) were used to assess soil microbial community composition. Application of PM resulted in greater concentrations of total nitrogen (TN), NH₄ ⁺-N, NO₃ ^?-N, total carbon (TC), soil organic matter (SOM) but lesser pH values. Soils with application rates of 88–222 g PM kg^?1, dm had concentrations of total and EDTA-extractable Cu and Zn significantly greater than those in soil without PM, and concentrations of T-Cu and T-Zn in these amended soils exceeded maximum limits set by standards in china. Except in the soil with a rate of 11 g PM kg^?1, dm, total bacterial and fungal PLFAs were directly proportional to rate of application of PM. Biomasses of bacteria and fungi were significantly greater in soils with application rates of 44–222 g PM kg^?1, dm than in the soil without PM. SOM, TC and EDTA-Zn had the most direct influence on soil microbial communities. To improve fertility of soils and maintain quality of soil, rate of application should be 22–44 g PM kg^?1 dm, soil containing Cu and Zn.     

基于3种时间序列模型的九龙江河流库区藻华预测

湖库富营养化和有害藻华是全球性生态环境问题,藻华预测与早期预警是保障湖库水源地供水安全的关键技术.如何基于高频水生态在线监测数据进行藻华的实时动态预测成为水生态管理领域的重大需求.本研究以福建省九龙江江东库区(水源地)为例,利用3年连续观测的逐时平均总叶绿素a浓度数据,对比研究了SARIMA、Prophet和LSTM(长短期记忆神经网络)3种时间序列模型在藻华(日平均叶绿素a大于15μg·L^-1)预测方面的效果.结果表明：(1)时间序列模型要求参数少,灵活性强,能清晰反映水质特征和未来变化趋势,可弥补传统藻类监测预警方法的局限性;(2)基于深度学习框架的LSTM模型,具有独特的迭代优化算法,对藻类非线性变化特征的识别和预测能力较强,其总叶绿素a逐日预测和7日预测效果均显著优于SARIMA模型和Prophet模型;(3)输入数据长度会在一定程度上影响模型预测效果,最优的输入数据时间长度为7 d;输入数据频率对预测效果也有影响,在预测非藻华日时,小时数据的预测效果优于日频率数据;在预测藻华日时,两种频率数据无显著差异,但日频率数据能更准确识别藻华日特征.总结起来,基于...     

富氧空位/梯次结构CeO2的制备及光催化CO2还原

采用Ce-BTC(均苯三甲酸)为模板,通过尿素溶液浸渍合成了具有富氧空位/梯次结构的CeO₂催化剂,并用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、拉曼光谱(Raman)和紫外可见漫反射(DRS)等手段对其进行了表征.结果表明,与金属有机框架(MOFs)浸渍尿素高温煅烧可以获得金属氧化物/g-C₃N₄复合材料不同,Ce-BTC/尿素体系煅烧后产品中未检测到g-C₃N₄,这可能与CeO₂的存在抑制了尿素分解产物的热缩聚过程,影响了g-C₃N₄的生成有关,但尿素的引入改变了Ce-BTC煅烧产物CeO₂的氧空位浓度,且获得梯次结构.将具有富氧空位/梯次结构的CeO₂-5用于光催化CO₂还原,催化结果表明:反应4h的CO产率可达2.06μmol/g,CH₄产率可达1.42μmol/g,性能是Ce-BTC未...     

郯城地区地下水化学特征及针对硝酸盐的健康风险评价

利用郯城地区100个地下水的水样监测数据,总结水化学特征,分析成因,并针对氮污染问题开展了硝酸盐健康风险评价.结果表明:区内地下水呈弱碱性,矿化度较低,总硬度为中等,水化学类型以HCO3-Ca型为主,但是氮污染严重.分析认为,地下水化学组成主要受岩石风化与人工施肥控制,碳酸盐岩和硅酸盐岩的风化溶解与氮肥施用是水化学现状...     

蚯蚓粪复配硼钼调理剂对土壤改良和茄子生长的影响作用

土壤质量决定着农产品的质量和农业生产的可持续发展,然而土壤退化成为农业生产的重要限制因素之一,施用土壤调理剂有利于减缓土壤退化的速度.该研究配制土壤调理剂,即蚯蚓粪?草菇渣?蛭石=6?3?1、钼酸钠50 g·kg?1、硼酸13.3 g·kg?1,并设5个不同的处理CK、QY-T1、QY-T2、QY-T3、QY-T4,研...