臭氧-活性污泥法深度处理己内酰胺生产废水

采用臭氧-活性污泥法深度处理己内酰胺生产废水。实验结果表明,当臭氧加入量60 mg/L、HRT=24 h时,出水COD=54.7 mg/L、出水ρ（NH₃-N）=2.0 mg/L,出水达到GB 8978—1996《污水综合排放标准》中的一级排放标准。比较了臭氧氧化法、臭氧-H₂O₂高级氧化法和臭氧-活性污泥法3种深度处理方法的运行成本,其中臭氧-活性污泥法运行成本最低,为1.650 元/t,且该方法运行稳定性高、操作简单,是3种深度处理方法中的最优方法。     

地表臭氧浓度升高对冬小麦和大豆生长和产量的影响

我国近地层臭氧污染日趋严重,其不断增加的浓度对农作物的生长造成了严重威胁。以冬小麦和大豆为研究对象,基于大田开顶式气室(OTC)试验,分别设置对照(CK)、100 n L·L~(-1)和150 n L·L~(-1)这3个O3浓度处理组,对2种作物生长指标和产量等参数连续观测,结果表明:O3浓度增加对冬小麦和大豆的株高、叶面积和生物量产生影响,并且对大豆的影响更为明显。与此同时,O3浓度增加使得冬小麦的穗重、穗粒数以及大豆的单株荚数、单株粒数、单株粒重都呈现大幅度下降状态,进而导致其产量降低。在100 n L·L~(-1)臭氧处理下,冬小麦产量较CK降低了12.89%,而大豆产量下降了23.76%。在150 n L·L~(-1)的臭氧处理下,冬小麦产量较对照组降低了29.23%,大豆则比对照组下降了41.57%,与CK相比,大豆产量下降更为明显。上述研究表明,臭氧污染对农作物的生长具有显著影响,且大豆对O3的反应比冬小麦敏感。     

陆地生态系统臭氧干沉降的观测和模拟研究进展

近地层臭氧(O_3)会对植物的生长和产量均产生一定的负效应。由于人类活动引起的不断升高的近地层O_3浓度已经威胁到世界粮食安全。O_3主要以干沉降的方式沉降到陆地生态系统,所以需要定量确定陆地生态系统中O_3通量、干沉降速率和不同沉降通道的沉降过程,预测其对植物的潜在影响。介绍了目前O_3干沉降的主要观测方法及其模拟模型,从4个方面(O_3通量和干沉降速率的季节变化、日变化、气象因子等对O_3干沉降的影响、不同O_3沉降通道的沉降过程)重点评述了不同陆地生态系统O_3干沉降观测和模拟的研究进展现状,并对未来的研究工作进行了展望,以期为我国未来开展相关研究工作提供借鉴。     

臭氧氧化—钙法吸收工艺对烟气的同步脱硫脱硝

针对中国石化镇海炼化乙烯动力锅炉烟气的特点,进行烟气模拟,采用臭氧氧化—钙法吸收同时脱硫脱硝工艺处理模拟烟气。实验对比了单独脱硫和脱硝过程与同时脱硫脱硝工艺的脱硫、脱硝效果,探究了烟气在反应器中的停留时间、臭氧投加量和烟气含氧量对SO₂去除率和NO_x去除率的影响。实验结果表明：SO₂和NO的共存可促进污染物的去除;烟气停留时间延长,SO₂去除率提高,NO_x去除率先升高后降低;臭氧与NO摩尔比增加,NO_x去除率提高,SO₂去除率略有降低。综合考虑选择烟气停留时间3.4 s,烟气含氧量12%（φ）,臭氧与NO摩尔比0.7,在此工艺条件下反应70 min,NO_x去除率为73.8%,SO₂去除率为74.1%。     

高级氧化法处理光引发剂生产废水

分别采用臭氧氧化、微电解—Fenton氧化和电化学降解的方法处理COD为6 000~8 000 mg/L、BOD₅/ COD为 0.12~0.17的光引发剂生产废水,比较了3种方法对废水中COD的去除效果。实验结果表明：臭氧氧化反应2 h时废水COD去除率达35.9%,BOD₅/COD 为0.20;微电解反应4 h再Fenton氧化4 h后,废水COD去除率为38.2%,BOD₅/COD 为0.28;电化学降解2 h后废水COD去除率达83.9%,BOD₅/COD 为0.46,降解反应遵循零级反应动力学,反应速率常数为2.6 kg/（m³·h）。3种方法对光引发剂生产废水的处理效果顺序为：电化学降解>微电解—Fenton氧化>臭氧氧化。     

Ozonation of whole wheat flour and wet milling effluent: Degradation of deoxynivalenol (DON) and rheological properties

The objective of this study was to evaluate the reduction on the levels of the mycotoxin deoxynivalenol (DON) in whole wheat flour (WWF) with different moisture levels, on the wet milling effluent through ozone (O₃) processing, as well as the impact of ozonation on the rheological properties of flour. The results have shown that the reduction of DON was improved with increasing moisture and exposure time of WWF and wet milling effluent to ozone. The maximum reduction was about 80%, proving that ozonation is an effective and promising technology in reducing mycotoxins in different products. However, the process altered the rheological profile of WWF. Therefore, further studies are needed to better understand the process.     

Meta-analysis of the Chinese studies of the association between ambient ozone and mortality

To investigate short-term effects of ambient ozone exposure on mortality in Chinese cities, we conducted a meta-analysis of 10 effect estimates of 5 short-term studies, which reported associations between ambient ozone and mortality in Chinese mainland cities. And we estimated pooled effects by non-accidental mortality, cardiovascular mortality, and respiratory mortality. Combined estimates and their 95%CI were tested by RevMan 5, and Funnel plots were used for the bias analysis. For a 10 μg m⁻³ increase of maximum 8-h average concentration of ozone, the percent change for non-accidental mortality, cardiovascular mortality, and respiratory mortality were 0.42 (95%CI, 0.32–0.52%), 0.44% (95%CI, 0.17–0.70%) and 0.50% (95%CI, 0.22–0.77%), respectively. Compared with pooled estimates from other meta-analyses on ambient ozone-associated mortality, our pooled estimate for non-accidental mortality was slightly higher than previous ones and pooled estimate for cardiovascular mortality was consistent with others. However, we observed significantly positive association between ambient ozone and respiratory mortality, which were generally nonsignificant in earlier studies. By combining estimates from published evidence, a small but substantial association between ambient ozone level and mortality was observed in Mainland China.     

臭氧氧化法处理反渗透浓缩垃圾渗滤液

采用臭氧氧化法处理经反渗透膜处理后的浓缩垃圾渗滤液,考察了反应时间、臭氧投量、pH和温度对COD,色度以及浓缩液中腐殖酸的去除影响,通过BOD₅/COD变化分析了臭氧氧化对浓缩液生化性的提高作用。结果表明：在pH 8.0,温度30℃,臭氧投量5 g/h,反应时间90 min的条件下,浓缩液的COD、色度以及浓缩液中腐殖酸的去除率分别达到67.6%、98.0%和86.1%, BOD₅/COD从0.008提升到0.26,生化性有很大提高。     

TS-1分子筛催化O_3/H_2O_2氧化乙酸

研究了酸性条件下TS-1分子筛催化O3/H2O2体系（O3/H2O2/TS-1）对降解水中乙酸效率的影响,优化了相关工艺参数,并对其作用机理进行了分析。结果表明,在pH为2.8时,TS-1的加入能显著提高臭氧化的降解效率。优化工艺参数表明,当过氧化氢投加量为3 g/L,TS-1投加量为5 g/L时,O3/H2O2/TS-1体系对乙酸具有较高的降解率,60 min后O3/H2 O2/TS-1体系对乙酸（初始浓度为100 mg/L）的去除率达到了58.7%。当pH为0.8时,O3/H2 O2/TS-1体系对乙酸的去除率仅为19.8%,降解效果较差。定量化计算表明,O3/H2O2和O3/H2O2/TS-1的Rct分别为1.62×10-8和8.67×10-7。通过测定乙酸降解过程水样中过氧化氢和液相臭氧的浓度变化,推测了具体反应机理。由于此体系在酸性条件下对乙酸有较好的降解效果,拓宽了现有O3/H2O2体系的应用范围。     

TS-1分子筛催化O3/H2O2氧化乙酸

研究了酸性条件下TS-1分子筛催化O3/H2O2体系(O3/H2O2/TS-1)对降解水中乙酸效率的影响,优化了相关工艺参数,并对其作用机理进行了分析。结果表明,在pH为2.8时,TS-1的加入能显著提高臭氧化的降解效率。优化工艺参数表明,当过氧化氢投加量为3 g/L,TS-1投加量为5 g/L时,O3/H2O2/TS-1体系对乙酸具有较高的降解率,60 min后O3/H2 O2/TS-1体系对乙酸(初始浓度为100 mg/L)的去除率达到了58.7%。当pH为0.8时,O3/H2 O2/TS-1体系对乙酸的去除率仅为19.8%,降解效果较差。定量化计算表明,O3/H2O2和O3/H2O2/TS-1的Rct分别为1.62×10-8和8.67×10-7。通过测定乙酸降解过程水样中过氧化氢和液相臭氧的浓度变化,推测了具体反应机理。由于此体系在酸性条件下对乙酸有较好的降解效果,拓宽了现有O3/H2O2体系的应用范围。