气象因素对泉州臭氧的影响

利用泉州城区2017年全年连续观测的O_3和气象要素资料,统计了臭氧浓度的分布特征,分析了气象要素对O_3质量浓度的影响,对比了O_3超标日和非超标日的气象要素特征。结果表明:(1)泉州市O_3质量浓度月变化呈双峰形,春季最高,夏季最低;日变化呈单峰形,最大值出现在13:00—14:00,最小值出现在06:00—07:00,上下游站O_3浓度存在明显传输效应。(2)泉州O_3质量浓度与相对湿度呈负相关,其相关性最高;与风速呈正相关,其相关系数最低,且存在明显区位性差异;与气温的相关性比较复杂,既有正相关,也有负相关。(3)各站点O_3小时质量浓度超标时,均对应2个气象要素区间值。(4)对比污染日非污染日发现,污染日相对湿度较低(50%～60%),非污染日较高(70%～80%);污染日温度略低于非污染日;污染日风向总体为西南偏南,非污染日风向为西南-东南。     

Crosslinking acrylamide with EDTA-intercalated layered double hydroxide for enhanced recovery of Cr(VI) and Congo red: Adsorptive and mechanistic study

• Functional groups of AM and EDTA in composite increased removal of Cr(VI) and CR. • Removal process reached equilibrium within 30 min and was minimally affected by pH. • Elimination of Cr(VI) was promoted by coexisting CR. • Adsorption process of CR was less influenced by the presence of Cr(VI). • Mechanisms were electrostatic attraction, surface complexation and anion exchange. We prepared ethylenediaminetetraacetic acid (EDTA)-intercalated MgAl-layered double hydroxide (LDH-EDTA), then grafted acrylamide (AM) to the LDH-EDTA by a cross-linking method to yield a LDH-EDTA-AM composite; we then evaluated its adsorptive ability for Congo red (CR) and hexavalent chromium (Cr(VI)) in single and binary adsorption systems. The adsorption process on LDH-EDTA-AM for CR and Cr(VI) achieved equilibrium quickly, and the removal efficiencies were minimally affected by initial pH. The maximum uptake quantities of CR and Cr(VI) on LDH-EDTA-AM were 632.9 and 48.47 mg/g, respectively. In mixed systems, chromate removal was stimulated by the presence of CR, while the adsorption efficiency of CR was almost not influenced by coexisting Cr(VI). The mechanisms involved electrostatic attraction, surface complexation, and anion exchange for the adsorption of both hazardous pollutants. In the Cr(VI) adsorption process, reduction also took place. The removal efficiencies in real contaminated water were all higher than those in the laboratory solutions.     

贵州丹寨废弃矿区典型农作物中汞、砷含量的分布特征及差异分析

为摸清废弃矿区重金属汞(Hg)、砷(As)在典型农作物中的含量和空间分布特征,于丹寨金汞矿废弃矿区选取当地主要种植作物-玉米和水稻,采用冷原子荧光光谱法和电感耦合等离子体质谱法分别对农作物Hg、As进行定量分析。结果表明:玉米植株中,茎叶Hg、As出现部分超标点,点位超标率分别为42.11%和5.26%,玉米果实中Hg、As均未超标;玉米Hg、As的空间分布特征表现为距离污染源越远浓度越低。而水稻植株中,茎叶及籽实Hg、As点位超标率和超标倍数均高于玉米,其中水稻茎叶Hg、As点位超标率分别为73.33%和26.67%;水稻中Hg含量随污染源距离的增加而降低,As随污染源距离的增加而增加。相关性研究表明,茎叶Hg和果实Hg不存在显著相关关系,而茎叶As和果实As存在较好的相关性,表明Hg在作物器官中的分布不均匀,而As的分布相对较均匀。玉米和水稻地上部分对Hg、As的生物富集系数均小于0.05,表明玉米和水稻从土壤吸收、并向地上部分转移Hg、As的能力较弱。金属Hg在农作物中的含量及富集系数均低于As,这可能与土壤重金属含量、矿区污染物的释放以及作物本身的耐受性和吸收机制不同有关。     

Fenton氧化法处理石化含油废水生化出水

采用Fenton氧化法处理石化含油废水生化出水,通过正交实验和单因素实验优化了反应工艺条件。正交实验得到各因素对COD去除率的影响大小顺序为:溶液初始pHH_2O_2投加量n(H_2O_2)∶n(Fe~(2+))反应温度。实验最佳工艺条件为:初始溶液pH 4.0,H_2O_2投加量3.00 mL/L,n(H_2O_2)∶n(Fe~(2+))=10,反应温度35℃,反应时间60 min。在此最佳工艺条件下COD可降至60.33 mg/L,COD去除率达61.33%。在最佳工艺条件下,分别采用超声(US)-Fenton氧化和紫外光(UV)-Fenton氧化技术处理含油废水生化出水,COD去除率分别达76.77%和80.23%。但单一Fenton氧化、US-Fenton氧化和UV-Fenton氧化工艺对NH_3-N的去除效果均并不明显。     

基于熵权的综合指数法在海水水质评价中的应用

将海水水质监测值和标准值相结合,建立水质评价矩阵,通过熵权法确定各评价指标权重,应用综合指数法对泉州湾水质进行评价。结果表明,2000年之前,泉州湾水质虽有所波动,但均明显优于三类水质标准。2001年泉州湾水质出现恶化,但仍优于四类水质标准。该研究改进了传统的海水水质评价方法,计算更为简便,评价结果更合理。     

Prevalence of coal worker’s pneumoconiosis: a systematic review and meta-analysis

Environmental Science and Pollution Research - Global prevalence trend and regional differences of coal worker’s pneumoconiosis (CWP) remain unclear. This study aimed to provide systematic...