O3-H2O2氧化法处理印染废水

采用O₃-H₂O₂氧化法对印染废水进行氧化处理，比较了O₃氧化法和O₃-H₂O₂氧化法对印染废水的处理效果，考察了初始废水pH、H₂O₂加入量、O₃流量和反应时间对废水的色度去除率和COD去除率的影响。实验结果表明：O₃-H₂O₂氧化法对废水的COD和色度的去除效果比O₃氧化法更好；在初始废水pH为11、H₂O₂加入量为13mmol/L、O₃流量为6g/h、反应时间为60min的最佳工艺条件下，处理后废水COD为61.50mg/L，COD去除率为95.73%，废水色度为5倍，色度去除率为99.75%，TOC为37.84mg/L，TOC去除率为85.10%，BOD₅为22.76mg/L，BOD₅去除率为90.20%，BOD₅/COD为0.37。     

Effect of ozonization in degradation of trifluralin residues in aqueous and food matrices

Abstract

This study investigates the oxidation of trifluralin residues during ozonation in aqueous and food matrices (tomato). Domestic ozonation equipment with average production of 23.9?mg O₃ L^?1 h^?1 was used in the tests. Modern chromatographic systems (SPME-GC-IT/MS/MS and QuEChERS-GC-IT/MS/MS) were applied for extraction and detection of trifluralin residue in fortified samples of ultrapure water, tap water, superficial water and tomato fruit. The samples were submitted to the ozonation process during 0, 5, 10 and 20?min. Treatment at 5?min was able to degrade 71.5% of herbicide trifluralin in surface water. The removal (%) in ultrapure water reached 83.4% after 20?min of ozonation. The degradation of trifluralin in fortified tomato samples (0.025–0.1?mg kg^?1) were conducted with ozonation at 20?min, and it ranged from 84.4 to 92.7%. After treatment, levels of trifluralin in tomato remained within the established MRLs to EU, USEPA and ANVISA (Brazil). The data provided evidence that ozone is effective for removing trace trifluralin from water and foods.     

Ti（Ⅳ）催化臭氧／过氧化氢预处理酸性难降解废水

在Ti（Ⅳ）和过氧化氢存在条件下，考察了臭氧化酸性苯乙酮溶液、硝基苯溶液和垃圾渗滤液（浙江衢州某垃圾填埋场）的预处理效能。结果表明，在pH2．86条件下，单独臭氧化处理对苯乙酮、硝基苯和垃圾渗滤液的COD去除率分别为10．1％、44％和28．6％。BOD，／COD值分别从原来的0．039、0．060和0．085提高到了0．130、0．158和0．174，仍属生化难降解废水。当体系加入Ti（Ⅳ）后，臭氧化苯乙酮和硝基苯的COD去除率分别达到了75．5％和65％，BOD；／COD则提高到了0．679和0．314，可生化性提升明显。对于垃圾渗滤液，只有当体系加入Ti（Ⅳ）和H22后，臭氧化COD的去除率达到66．6％，BOD、／COD提高至0．425。上述结果对酸性难降解废水的处理实际意义非常突出。     

沿面放电氧化液相亚硫酸铵

为了解决湿式氨法烟气脱硫生成不稳定亚硫酸铵（（NH4）2SO3）副产物的问题,设计了以不锈钢弹簧和溶液分别作为高压和低压电极的沿面放电系统,对液相（NH4）2SO3的氧化进行了研究。空气从反应器上方进入后经放电区域形成活性物质,再由底部的曝气头鼓入溶液并与（NH4）2SO3发生反应。比较了沿面放电处理与传统曝气处理的氧化效率,考察了放电电压、载气气量和初始浓度等因素对（NH4）2SO3氧化的影响。结果表明,沿面放电对（NH4）2SO3有显著的氧化效果;优化条件下的（NH4）2SO3氧化率接近100%;溶液中（NH4）2SO4与（NH4）2SO3的浓度比小于1时有利于（NH4）2SO3的氧化。     

臭氧-BAF组合工艺对石化行业废水深度处理的中试研究

采用臭氧-曝气生物滤池（BAF）组合工艺对中石化九江分公司二级生化出水进行深度处理中试实验。探讨了臭氧投加量、进水水质冲击负荷等因素对该组合工艺出水COD、NH₄⁺-N的影响。中试结果表明，在该水质条件下，臭氧最佳投加量为20~25 mg/L；组合工艺处理后出水COD低于40 mg/L，NH₄⁺-N低于5 mg/L，达到中水回用设计标准；该组合工艺能够经受一定冲击负荷。     

城市污水厂二级处理出水深度处理组合工艺研究

为了研究臭氧-曝气生物滤池二级处理出水深度处理组合工艺的处理效果，采用臭氧-曝气生物滤池(biological aerated filter， BAF)组合工艺对城市污水处理厂二级生化处理出水进行深度处理。结果表明，组合工艺对造成水中色度的主要物质腐植酸和富里酸类有机物和嗅味物质中的二甲基三硫和二甲基异莰醇(MIB)能够进行有效去除。臭氧氧化能够显著提高后续BAF单元对COD_Mn的去除。在进水COD_Mn6~8 mg/L、色度为25~30度、浊度约为8 NTU的条件下，当臭氧投加量为5~6 mg/L、BAF的水力停留时间为1~1.5 h时，出水COD_Mn< 5 mg/L、色度<5度、浊度<1 NTU，出水水质可满足生产工艺对回用水的水质要求。     

Species-specific effects of elevated ozone on wetland plants and decomposition processes

Seven species from two contrasting wetlands, an upland bog and a lowland rich fen in North Wales, UK, were exposed to elevated ozone (150 ppb for 5 days and 20 ppb for 2 days per week) or low ozone (20 ppb) for four weeks in solardomes. The rich fen species were: Molinia caerulea, Juncus subnodulosus, Potentilla erecta and Hydrocotyle vulgaris and the bog species were: Carex echinata, Potentilla erecta and Festuca rubra. Senescence significantly increased under elevated ozone in all seven species but only Molinia caerulea showed a reduction in biomass under elevated ozone. Decomposition rates of plants exposed to elevated ozone, as measured by carbon dioxide efflux from dried plant material inoculated with peat slurry, increased for Potentilla erecta with higher hydrolytic enzyme activities. In contrast, a decrease in enzyme activities and a non-significant decrease in carbon dioxide efflux occurred in the grasses, sedge and rush species.     

Calculating losses of crops in Denmark caused by high ozone levels

In order to help guide air pollution legislation at the European level, harmful air pollution effects on agriculture crops and the consequent economic implications for policy have been studied for more than a decade. Ozone has been labeled as the most serious of the damaging air pollutants to agriculture, where growth rates and consequently yields are dramatically reduced. Quantifying the effects has formed a key factor in policymaking. Based on the widely held view that AOT40 (Accumulated exposure Over Threshold of 40 ppb) is a good indicator of ozone-induced damage, the Danish Eulerian Model (DEM) was used to compute reduced agriculture yields on a 50 km×50 km grid over Europe. In one set of scenarios, a ten year meteorological time series was combined with realistic emission inventories. In another, various idealized emission reduction scenarios are applied to the same meteorological time series. The results show substantial inter-annual variability in economic losses, due in most part to meteorological conditions which varied much more substantially than the emissions during the same period. It is further shown that, taking all uncertainties into account, estimates of ozone-induced economic losses require that a long meteorological record is included in the analysis, for statistical significance to be improved to acceptable levels for use in policy analysis. In this study, calculations were made for Europe as a whole, though this paper presents results relevant for Denmark.     

The impact of ambient ozone on mountain spruce forests in the Czech Republic as indicated by malondialdehyde

Malondialdehyde (MDA), a product of lipid peroxidation and biomarker of oxidative stress, is measured over the long term in spruce Picea abies needles under real conditions in three Czech mountain border areas. The trends presented collate the MDA content in spruce needles with ambient ozone, temperature and precipitation as casual, and defoliation as a subsequent factor for the period 1994-2006. We have found the overall decreasing trends in MDA and defoliation. The highest MDA and defoliation are recorded in the Jizerske, the lowest in the Krusne hory Mts. Out of the examined variables the MDA is predicted best by mean temperature in vegetation season, median of O₃ concentrations and AOT40; these three variables account for 34% of MDA1 and 36% of MDA2 variability. Our hypothesis that higher ambient O₃ exposure results in higher MDA contents in P. abies needles under real conditions has not been approved.     

Protection of palak (Beta vulgaris L. var Allgreen) plants from ozone injury by ethylenediurea (EDU): Roles of biochemical and physiological variations in alleviating the adverse impacts

Ameliorative effects of ethylenediurea (N-[2-(2-oxo-1-imidazolinidyl) ethyl]-N′ phenylurea, abbreviated as EDU) against ozone stress were studied on selected growth, biochemical, physiological and yield characteristics of palak (Beta vulgaris L. var Allgreen) plants grown in field at a suburban site of Varanasi, India. Mean eight hourly ozone concentration varied from 52 to 73 ppb which was found to produce adverse impacts on plant functioning and growth characteristics. The palak plants were treated with 300 ppm EDU at 10 days after germination at 10 days interval up to the plant maturity. Lipid peroxidation in EDU treated plants declined significantly as compared to non-EDU treated ones. Significant increment in F_v/F_m ratio in EDU treated plants as compared to non-EDU treated ones was recorded. EDU treated plants showed significant increment in ascorbic acid contents and reduction in peroxidase activity as compared to non-EDU treated ones. As a result of the protection provided by EDU against ozone induced stress on biochemical and physiological characteristics of palak, the morphological parameters also responded positively. Significant increments were recorded in shoot length, number of leaves plant⁻¹, leaf area and root and shoot biomass of EDU treated plants as compared to non-EDU treated ones. Contents of Na, K, Ca, Mg and Fe were higher in EDU treated plants as compared to non-EDU treated ones. The present investigation proves the usefulness of EDU in partially ameliorating ozone injury in ambient conditions.