达州市城区环境空气质量变化趋势及CMAQ模型预报分析

利用Spearman秩相关系数法、污染日历图、浓度分析法和CMAQ预测模型研究了达州市城区2015—2019年空气质量状况。结果表明:2015—2019年,达州市城区O_3浓度变化趋势为显著上升(P0.05),季度变化明显,8月易发生因O_3超标导致的轻度污染状况;CO年均值变化趋势为显著降低(P0.05);NO_2年均值呈上升趋势,但尚未达到显著水平(P0.05);SO_2、PM_(10)和PM_(2.5)年均值呈下降趋势,但变化趋势不明显(P0.05)。2019年,1月和12月污染最重,PM_(2.5)超标是主因,PM_(10)和PM_(2.5)年均值达标形势严峻,全年一半以上天数的PM_(2.5)浓度超过年均值二级标准限值,PM_(10)也近半;NO_2年均值达标形势严峻,全年212 d超过年均值二级标准限值。CMAQ模型对不同污染指标的预测准确率不同,预测PM_(2.5)浓度、首要污染物和空气质量等级时的准确率不及人工预测,预测AQI时的准确率高于人工预测,更多污染指标的预测比较还有待进一步研究。     

衡阳市区和衡山背景站臭氧浓度变化规律的对比分析

选取衡阳市区和衡山背景站臭氧自动监测数据,分析两地的臭氧污染特征。对空气质量的优良率情况、臭氧作为首要污染物的变化情况、臭氧浓度的日变化特征、典型时段的浓度变化特征、臭氧浓度的月际变化特征和臭氧与PM_(2.5)的关联情况等进行了分析。结果表明,多云及阴雨天气时,衡阳市区的臭氧浓度日变化幅度大于衡山背景站。夏季,衡阳市区和衡山背景站的臭氧浓度的日变化特征规律差异较大,臭氧浓度分布比较分散,前者为典型的单峰形,后者则波动平缓。冬季,日变化幅度不大,但衡阳市区的臭氧浓度明显低于衡山背景站。衡山背景站和衡阳市区的臭氧基本同步变化,但日均值高于衡阳市区。     

地表水环境遥感监测关键技术与系统

介绍了地表水环境遥感监测的关键技术与系统及其典型应用,其代表性机理模型和应用示范成果主要来自于中国科学院遥感与数字地球研究所的高光谱遥感团队在最近几年中取得的一些研究进展,主要包括建立了基于改进双峰法的水体分布自动化遥感提取方法,实现了简单、高效和高精度的水体提取；提出了大型湖泊长时序水量估算方法,并以青藏高原湖区为例,重建了典型湖泊面积、水位和水量序列；发展了基于“软分类”的典型内陆水体叶绿素a浓度反演方法,构建了基于生物光学模型的高度浑浊水体悬浮物浓度遥感反演半解析方法,提高了反演方法的区域和季节适用性；构建了基于水色指数的大范围湖库营养状态和透明度遥感监测方法,实现了全球大型湖库营养状态遥感监测,以及全国大型湖库透明度遥感监测；在此基础上,开发了地表水环境遥感监测系统,提高了水环境遥感监测效率,促进了卫星遥感在水环境监测中的高精度业务化应用。     

混合酸消解变化对土壤和沉积物中痕量硒分析影响

基于各3种采集环境样本、国家标准物质的土壤和沉积物,以当前环境监测行业常用的3种消解方法,探讨20种混合酸系统条件在消解条件变化中对复杂样本硒元素测定的影响。确定了最佳土壤和沉积物消解的组合为王水系统(盐酸∶硝酸∶氢氟酸∶过氧化氢∶高氯酸=3∶1∶1∶1∶1),各消解法的处理结果部分(n=5)∶水浴法消解时间仅需0.5h,总处理时间2h,准确度回收率达101%~104%,精密度RSD为1.95%~2.20%;电热板法总处理时间较长(7.5h),回收率106%,RSD偏高为8.46%,不推荐使用;微波法处理的总时间亦长达7.0h,回收率93.8%,但精密度亦偏高为8.24%,因此采用水浴法应用于环境样本的测定。该优化消解方法已直接应用于环境中农业、建筑用土和管道淤泥沉积物的3种样品类型前处理,利用同一优化条件即可快速对应土壤和沉积物性质样品,单次可批量处理72~84个样本,解决高通量样品痕量硒测定需求,提供环境污染监测和检测行业一参考依据。     

A remote sensing tool for near real-time monitoring of harmful algal blooms and turbidity in reservoirs

Harmful algal blooms (HABs) diminish the utility of reservoirs for drinking water supply, irrigation, recreation, and ecosystem service provision. HABs decrease water quality and are a significant health concern in surface water bodies. Near real-time monitoring of HABs in reservoirs and small water bodies is essential to understand the dynamics of turbidity and HAB formation. This study uses satellite imagery to remotely sense chlorophyll-a concentrations (chl-a), phycocyanin concentrations, and turbidity in two reservoirs, the Grand Lake O′ the Cherokees and Hudson Reservoir, OK, USA, to develop a tool for near real-time monitoring of HABs. Landsat-8 and Sentinel-2 imagery from 2013 to 2017 and from 2015 to 2020 were used to train and test three different models that include multiple regression, support vector regression (SVR), and random forest regression (RFR). Performance was assessed by comparing the three models to estimate chl-a, phycocyanin, and turbidity. The results showed that RFR achieved the best performance, with R² values of 0.75, 0.82, and 0.79 for chl-a, turbidity, and phycocyanin, while multiple regression had R² values of 0.29, 0.51, and 0.46 and SVR had R² values of 0.58, 0.62, and 0.61 on the testing datasets, respectively. This paper examines the potential of the developed open-source satellite remote sensing tool for monitoring reservoirs in Oklahoma to assess spatial and temporal variations in surface water quality.     

乙酰丙酮荧光法在线监测环境空气中的甲醛

我国现行环境空气中甲醛的标准测定方法普遍难以满足当前大气监测中对痕量浓度水平甲醛的监测需要。在乙酰丙酮分光光度法的基础上改进得到的乙酰丙酮荧光法具有更低的检出限和更高的灵敏度，适用于大气中痕量浓度水平甲醛的监测。基于乙酰丙酮荧光法设计了甲醛在线监测系统，并对其主要性能指标进行了评估测试。测试结果显示，该系统的吸收效率为98.9%~100.1%，检出限为0.045 4×10^-9，精密度为0.44%，线性误差为-0.55%，线性范围为0.0~80.0×10^-9，响应时间为282 s，单日零点漂移为-0.04×10^-9~1.33×10^-9，单日跨度漂移为-0.90×10^-9~3.45×10^-9。测试结果表明，其各项性能指标均能满足当前对大气环境中痕量浓度水平甲醛的监测需求。     

A new prediction method of industrial atmospheric pollutant emission intensity based on pollutant emission standard quantification

● Established a quantification method of pollutant emission standard. ● Predicted the SO₂ emission intensity of single coking enterprises in China. ● Evaluated the influence of pollutant discharge standard on prediction accuracy. ● Analyzed the SO₂ emissions of Chinese provincial and municipal coking enterprises. Industrial emissions are the main source of atmospheric pollutants in China. Accurate and reasonable prediction of the emission of atmospheric pollutants from single enterprise can determine the exact source of atmospheric pollutants and control atmospheric pollution precisely. Based on China’s coking enterprises in 2020, we proposed a quantitative method for pollutant emission standards and introduced the quantification results of pollutant emission standards (QRPES) into the construction of support vector regression (SVR) and random forest regression (RFR) prediction methods for SO₂ emission of coking enterprises in China. The results show that, affected by the types of coke ovens and regions, China’s current coking enterprises have implemented a total of 21 emission standards, with marked differences. After adding QRPES, it was found that the root mean squared error (RMSE) of SVR and RFR decreased from 0.055 kt/a and 0.059 kt/a to 0.045 kt/a and 0.039 kt/a, and theR² increased from 0.890 and 0.881 to 0.926 and 0.945, respectively. This shows that the QRPES can greatly improve the prediction accuracy, and the SO₂ emissions of each enterprise are highly correlated with the strictness of standards. The predicted result shows that 45% of SO₂ emissions from Chinese coking enterprises are concentrated in Shanxi, Shaanxi and Hebei provinces in central China. The method created in this paper fills in the blank of forecasting method of air pollutant emission intensity of single enterprise and is of great help to the accurate control of air pollutants.     

固定源排污许可证监测管理制度研究

依靠排污许可证管理,固定源执行由行业排放标准为主正逐步过渡到"国家行业排放标准——单一源排放标准"双层排放标准,并以执行更全面和精准的单一源排放标准为主,对应的监测要求及考核方式更加多样化。对监测管理制度进行设计,明确固定源制定自行监测方案和守法监测的主体责任,厘清许可证核发部门、属地监测、执法部门的监管职责。系统设计"固定源制定并提交自行监测方案-核发部门审核-方案纳入排污许可证中成为规定-依规定自行监测和记录-固定源提交执行报告-监管部门审计式审核-执法监测和执法检查"的全过程管理机制,设计标准化的监管计划程序落实证后监管与执法监测,明晰监管部门的有限责任。     

天水市紫外吸收性气溶胶时空动态的遥感监测

采用OMI传感器的气溶胶产品,分析了2006—2015年中国西部城市天水市对流层紫外吸收性气溶胶的时空分布特征。结果表明:空间上,十年间天水市的吸收性气溶胶表现出从中部向周围依次减弱的南北向带状分布规律;季节变化呈现出秋冬季高于春夏季的规律;时间上,吸收性气溶胶指数(AI)从2006年的0.075增至2015年的0.506,年均值为0.28,年均增长率为57.5%;十年间出现2次阶段性增长和2次阶段性减小;AI年际变化与天水市地方总产值相关性为0.902,第一产业对其影响最大,第三产业影响最小。     

浅谈县级环境监测质量管理工作现状及对策

当前环保系统垂直改革稳步推进,县级环境监测质量管理工作也迎来新的机遇与挑战。从县级环境监测站质量管理工作现状着手,分析新形势下存在质量管理体系有效性缺乏、现场监测过程质量管理薄弱、质量管理意识尚待提高等问题。提出,应从加强体系建设、提高现场监测水平、强化考核培训力度等方面改进县级环境监测质量管理工作水平。