焦化废水后物化处理的臭氧-混凝-吸附原理选择与协同机制

以焦化废水生物出水为研究对象,对比了活性炭吸附、混凝沉淀、臭氧氧化原理及其协同的工艺技术处理效果,考察处理前后废水的分子量分布、紫外可见光谱、三维荧光光谱（EEM）和GC/MS等表征的溶液性质变化.结果表明,废水生物工艺出水的后物化深度处理的最佳组合原理序列为臭氧-混凝-吸附,响应曲面模型预测的最优反应条件为：臭氧反应时间62.56 min,聚合硫酸铁（PFS）投加量为0.87 g·L^-1,以及活性炭投加量为1.10 g·L^-1.实验过程的总有机碳（TOC）去除率达到98.29%,与模拟值98.74%相对偏差为0.45%.活性炭吸附、混凝沉淀和臭氧氧化3种技术原理对焦化废水生物出水中污染物具有选择性分离与转化的作用,组合工艺能够实现废水中残余组分有机物、UV₂₅₄吸光物质、荧光物质等的有效去除,存在废水溶液性质与工艺技术原理有效性协同增强的操作空间.     

Correction Factors for Covariance between Concentration and Deposition Velocity on CASTNes HNO3 Deposition Estimates

The covariance between hourly concentration (C) and depositionvelocity (V) for various atmospheric species may act to bias the dry deposition (D) computed from the product of the weeklyaverage C and V. This is a potential problem for the CASTNet filter pack (FP) species, nitric acid (HNO₃). Using ozone (O₃) behavior as a surrogate for HNO₃, correctionfactors (CF) are developed to estimate this bias. Weekly CF for O₃ depend on both site and season, and seasonal average weekly CF for O₃ at a given site may be as high as 1.25.The seasonal magnitude of this CF is generally largest in summerand is ordered: summer fall spring > winter. The CF is drivento a large extent by the diurnal correlation between C andV (i.e., both are generally higher during the day and lower at night). However, since the diurnal C profile at elevated sites is relatively constant, the resulting correlation between C and V is small, and the CF at montane sites is generally negligiblysmall. The sampling protocol using daytime integrated sampling for a week and nighttime integrated sampling for a week capturesthe diurnal correlation between C and V adequately and may be used to aggregate relatively unbiased weekly D estimates. Day-night CF for O₃ are close to unity, and limited results suggest similar behavior for HNO₃. Using these limited FP results, the site- and seasonally-specific weekly CF forO₃are refined to estimate the corresponding CF for HNO₃. Worst-case adjustments for HNO₃ as high as 30% are indicated for summer periods at a given site.     

Ozone Episode in the Milan Metropolitan Area A Comparative Evaluation of UAM-V and CALGRID Models

Data from an ozone episode (2–5 June, 1998) in the Milan metropolitan area were used for an application of two photochemical grid models: UAM-V and CALGRID. To assure a fair comparison, the models were run on the same domain and grid size, with same source emission inputs, CALMET diagnostic meteorology, and initial and boundary conditions taken from air quality data and literature values. Hourly emissions were derived from the AutoOil-II programme inventory except for on-road mobile source emissions; a new traffic emission inventory, based on both COPERT II methodology and road classification has been developed. NO_x and O₃ concentration results were compared to local network monitoring data. Results indicate that both models predict the highest ozone values along the north-east direction and are able to reproduce the ozone daytime trend though differences can be found between the two models on ozone spatial distribution. Average normalised bias for both models is about 50%, peak daily ozone concentrations are underestimated, with simulated peak shapes broader than the observed ones and a temporal shift between the two models. Night-time concentration levels of pollutants were not successfully reproduced due to an incorrect parameterisation of vertical turbulence calling for further work.     

The effect of elevated UV-B (280–320 nm) radiation levels on Silene vulgaris: A comparison between a highland and a lowland population

Highland (altitude 1600 m above sea level) and lowland (altitude −2 m below sea level) populations of the perennial herb Silene vulgaris (Moench) Garcke, were tested on their response to elevated levels of UV-B radiation. Highland populations typically receive high natural UV-B fluxes, whereas lowland populations receive a lower natural UV-B dose. Adaptation to high UV-B levels of the highland population is to be expected. Experimental comparison of growth rates, gas exchange rates, transpiration and biochemical parameters using adult plants as well as seedlings did not show a difference in the response to elevated UV-B levels between the two populations. Individuals of both populations were relatively insensitive to elevated UV-B radiation. The response of alpine and lowland populations of Silene vulgaris is discussed in relation to the dispersal of this species after the last ice age.     

Foliar Phenolics in Sugar Maple (Acer Saccharum) as a Potential Indicator of Tropospheric Ozone Pollution

Tropospheric O₃ has been implicated in the declining health of forest ecosystems in Europe and North America and has been shown to have negative consequences on human health. We have measured tropospheric ozone (O₃) in the lower canopy through the use of passive monitors located in five woodlots along a 150 km urban–rural transect, originating in the large urban complex of Toronto, Canada. We also sampled foliage from 10 mature sugar maple trees in each woodlot and measured the concentration of a number of phenolic compounds and macronutrients. O₃ concentrations were highest in the two rural woodlots, located approximately 150 km downwind of Toronto, when compared to the woodlots found within the Greater Toronto Area. Foliar concentrations of three flavonoids, avicularin, isoquercitrin, and quercitrin, were significantly greater and nitrogen concentrations significantly lower at these same rural woodlots, suggesting some physiological disruption is occurring in those sites where exposure to tropospheric O₃ is greater. We suggest that foliar phenolics of sugar maple may be a biochemical indicator of tropospheric ozone exposure.     

Ozone Deposition to a Coniferous and Deciduous Forest in the Czech Republic

Estimates of ozone concentration and deposition flux to coniferous and deciduous forest in the Czech Republic on a 1 × 1 km grid during growing season (April–September) of the year 2001 are presented. Ozone deposition flux was derived from ozone concentrations in the atmosphere and from its deposition velocities. To quantify the spatial pattern in surface concentrations at 1 km resolution incorporating topography, empirical methods are used. The procedure maps ozone concentrations from the period of the day when measurements are representative for the forest areas of countryside. The effects of boundary layer stability are quantified using the observed relationship between the diurnal variability of surface ozone concentration and altitude. Ozone deposition velocities were calculated according to a multiple resistance model incorporating aerodynamic resistance (R _a ), laminar layer resistance (R _b ) and surface resistance (R _c ). Surface resistance (R _c ) comprises stomatal resistance (R _sto ). R _sto was calculated with respect to global radiation, surface air temperature and land cover. Modelled total and stomatal ozone fluxes are compared with the maps describing equivalent values of AOT40 (accumulated exposure over threshold of 40 ppb). For forests, the critical level (9,000 ppbh May–July daylight hours) is exceeded over 50% of forested territory. This indicates the potential for effects on large areas of forest. There is significiant correspondence between the exposure index AOT40 and the total ozone flux, but the relation between the total ozone flux and AOT40 exposure index is not clear in all parts of the forest territory.     

高压窄脉冲臭氧发生器电源的研究

臭氧作为一种广谱灭菌和强氧化剂的应用越来越广，然而在实际应用中由于臭氧发生器所使用是高压脉冲电源，易受环境因素的影响，性能不稳定，可行性差，能耗高，影响了臭氧技术的应用，本文介绍了一种新型臭氧发生器的电源电路，它采用绝缘栅双极性IGBT作为功率开关管，并采PPWM脉宽调节方式稳定电压，具有较高的频率和较窄的脉冲上升沿，能满足臭氧发生器电源大功率，高性能稳定性，高效率的要求。     

O3/H2O2氧化工艺去除水中硝基苯的研究

以硝基苯为代表性有机污染物 ,对比了臭氧化和O3/H2 O2 高级氧化工艺对水中硝基苯的去除效果 .发现与臭氧化相比 ,O3/H2 O2 高级氧化工艺可以显著地提高水中硝基苯的去除效率 .无论在臭氧化还是在O3/H2 O2 高级氧化工艺中 ,水中硝基苯的降解都主要是由OH·完成的 .通过考察O3/H2 O2 高级氧化工艺去除水中硝基苯的影响因素发现 ,在O3和过H2 O2 投量相同的条件下 ,多次投加O3和催化剂H2 O2 对水中硝基苯的处理效果明显优于一次性投加 ;在本次试验条件下 ,O3/H2 O2 高级氧化工艺降解蒸馏水和自来水中硝基苯的最优H2 O2 与O3摩尔比均为 0 5 ,HCO- 3碱度水平 (以CaCO3计 )在低于 1 0 0mg/L范围内对去除硝基苯无显著影响     

关于京津地区臭氧（O3）污染问题

1983—1986年测量了京津地区的臭氧浓度。发现其浓度的全年季节和日变化一般与日照强度变化一致。并且浓度有逐年增加的趋势,还发现下风方向浓度高于上风方向及夜间多次出现峰值的现象。     

Impacts of ozone on the biomass and yield of rice in open-top chambers

ＩｎｔｒｏｄｕｃｔｉｏｎＯｚｏｎｅ(Ｏ3)ｆｏｒｍｅｄａｓｐｈｏｔｏｃｈｅｍｉｃａｌｓｍｏｇｉｓｔｈｅｍｏｓｔｄａｎｇｅｒａｎｄｗｉｄｅｓｐｒｅａｄｃｏｍｐｏｎｅｎｔｉｎｔｈｅａｉｒｐｏｌｌｕｔｉｏｎ.Ｎｏｗａｄａｙｓ,ｔｈｅｔｙｐｉｃａｌｄａｉｌｙｍａｘｉｍｕｍＯ3ｃｏｎｃｅｎｔｒａｔｉｏｎｓｉｎｕｒｂａｎｓｕｂｕｒｂａｎａｎｄａｒｅａｓｈａｖｅｒｅａｃｈｅｄ100～400ｎｌ/Ｌａｎｄ50～120ｎｌ/Ｌ,ｒｅｓｐｅｃｔｉｖｅｌｙ.Ｕｎｄｅｒｃｅｒｔａｉｎｍｅｔｅｏｒｏｌｏｇｉｃａｌｃｏｎｄｉｔｉｏｎｒｕｒａｌ…