强电离放电产生臭氧等离子体过程及其应用研究

电子从强电场（＞300Td)放电过程中取得的平均能量大于8.4eV；促使氧分子分解，分解电离成高浓度的氧原子，氧原子离子，从而产生高浓度（＞200g/Nm^3）臭氧，实现了用电离放电场的物理量控制臭氧产生浓度，产生效率及臭氧分解速率，并实现臭氧产生装置小型化，极大地拓宽了臭氧在环境工程领域上的应用。     

制取高浓度臭氧水的实验研究

采用介质阻挡强电离放电技术制取高浓度臭氧 ,使用射流器和气液溶解分离器溶解臭氧制取高浓度臭氧水。讨论了应用臭氧量、气液比、系统压力和气液溶解方式对臭氧水浓度和臭氧有效溶解效率的影响     

SO2、NO对汞在湿法电除尘器中脱除的影响

湿法电除尘器(WESP)作为一种控制烟气中超细颗粒物的有效手段被应用于燃煤电厂的超低排放改造中,然而烟气中的Hg~0受电场、水膜、烟气组分等因素的影响在WESP中的协同脱除机理尚不明确。为了深入了解该机理,探讨了WESP电场和水膜对Hg~0的控制机理,并进一步研究了烟气中SO_2、NO对Hg~0在WESP中脱除的影响。结果表明:电场静电作用对烟气中Hg~0脱除贡献较小,O_2电离产物?O对Hg~0的氧化作用是O_2促进Hg~0脱除的主要途径,水蒸气通过电离产生?OH促进Hg~0氧化以及通过黏附作用促进Hg~0脱除;水膜的裹挟作用对WESP系统Hg~0的脱除贡献较小,溶于水中的汞不稳定且容易再释放;SO_2、NO均通过在电场中电离产生?O促进Hg~0氧化脱除,其中,SO_2及其电离产物溶于水膜后可以与Hg~(2+)形成稳定配合物抑制汞的再释放,而NO的电离产物在水膜中对汞再释放的抑制作用较小。     

制取高浓度臭氧水的实验研究

采用介质阻挡强电离放电技术制取高浓度臭氧，使用射流器和气液溶解分离器溶解臭氧制取高浓度臭氧水，讨论了应用臭氧量，气液比，系统压力和气液溶解方式对臭氧水浓度和臭氧有效溶解效率的影响。     

应用臭氧氧化技术深度处理油船含油压载水的实验研究

油船含油压载水大量排放入海会对海洋生态环境产生较大的危害。在研究中,通过强电离放电技术制取高浓度臭氧,应用臭氧氧化方法来深度处理含油压载水,模拟实验表明在臭氧投加浓度达到120mg/L,在较短的接触时间(2min)内,臭氧对不同浓度的含油压载水中的油去除率可达到50%以上,同时使芳香族类物质显著减少,降低含油污水的生物毒性,处理方法具有可观的应用前景。     

应用臭氧氧化技术深度处理油船含油压载水的实验研究

油船含油压载水大量排放入海会对海洋生态环境产生较大的危害。在研究中，通过强电离放电技术制取高浓度臭氧，应用臭氧氧化方法来深度处理含油压载水，模拟实验表明在臭氧投加浓度达到120mg／L，在较短的接触时问(2min)内，臭氧对不同浓度的含油压载水中的油去除率可达到50％以上，同时使芳香族类物质显著减少，降低含油污水的生物毒性，处理方法具有可观的应用前景。     

紫外光助臭氧化处理活性艳红K-2BP废水研究

以 30 0W高压汞灯为光源 ,研究了紫外光联合臭氧化、单纯臭氧氧化及单纯紫外光照处理 4 0 0mg/L的活性艳红K 2BP废水的可行性。结果表明 :光催化臭氧化可加速有机物的矿化。在同样时间条件下 ,三者氧化能力由大至小为 :UV/O3 >单独O3 >单独UV。运用TOC、紫外 可见光谱 (UV Vis)、毛细管电泳 (CE)等分析技术初步探讨了紫外光催化臭氧化活性艳红K 2BP溶液的降解效果及降解机理。     

臭氧氧化降解含染料废水的研究

探讨了臭氧氧化技术处理染料 (酸性、直接、活性、分散和还原颜料 )模拟废水的影响因素———pH值、初始浓度和臭氧含量等对其的影响 ;臭氧氧化能提高染料废水的可生化性 ,可用来作为高浓度染料废水的预处理手段     

臭氧氧化污泥的试验研究

采用接触反应柱对污泥臭氧氧化过程中污泥性质的变化进行了研究。结果表明,在相同臭氧投量下,低浓度臭氧分解污泥的效率较高;在臭氧投量为0．1gO3／gss、臭氧浓度为16．8mg／L时,臭氧化使污泥溶液中的溶解性TOC从114．9mg／L增加到803．7mg／L;臭氧氧化后溶解性IC(无机碳)从2．63mg／L减少到1．02mg／L;臭氧氧化显著提高了污泥沉淀性能,氧化后污泥的SV和SVI相当于氧化前28．9％和58％。臭氧氧化使污泥的pH从初始的7．13降低到投量增加到0．44gO3／gss时的4．40。污泥臭氧化的最佳投量点为0．1gO3／gSS。     

本期推荐

<正>本期"水污染防治"栏目刊发了《林可霉素制药废水的臭氧氧化处理》(谷永,田哲,唐妹,苑宏英,杨敏,张昱)一文。在抗生素发酵过程中产生的废母液通常含有高浓度的抗生素,如果采用常规的生物工艺进行处理,抗生素残留效价会影响生物处理系统的功能,并可能导致生物处理细菌抗药基因产生和排放。前期工作表明,很多发酵类抗生素可以通过强化水解预处理进行去除,并成功在制药行业进行了工程应用。     

Responses of spring wheat (Triticum aestivum L.) to ozone produced by either electric discharge and dry air or by UV-lamps and ambient air

The aim of the present study was to examine if ozone produced similar effects on spring wheat growth with and without small amounts of nitrogen oxides. Two methods were used to produce ozone: the first method consisted of dry pressurized air fed to an electric discharge generator generating the byproducts, N2O5 and N2O, the second method consisted of ambient air fed to UV-lamps. Two spring wheat cultivars (Triticum aestivum L. cvs Minaret and Eridano) were exposed in small open-top chambers to charcoal-filtered air, non-filtered ambient air, and non-filtered ambient air with the addition of ozone for 8 h (0900 to 1700 h) daily, for five weeks. Plants were harvested every week. The growth of Minaret was shown to be more sensitive to O3 than that of Eridano. Leaf senescence increased with increasing ozone level in both cultivars. The total above-ground biomass dry weight decreased with increasing ozone concentration in Minaret, but not in Eridano. The Minaret plants reacted with more damaged leaf dry weight and inhibition of growth when O3 was produced by UV-lamps than when O3 was produced by air fed to an electric discharge generator. This could be explained by more nitrogen content per plant but not by increased nitrogen concentration in plant tissue in plants exposed to increased O3 and small amounts of incidental nitrogen oxides.     

臭氧洗消化学战剂模拟剂DPCP试验研究

用臭氧对神经性化学战剂的模拟剂氯磷酸二苯酯（DPCP）进行洗消,试验考察了初始酸度、O₂流量、放电功率、放电室压力、反应温度、初始浓度和O₃流量等因素对DPCP降解率的影响。碱性条件下DPCP降解率高于酸性条件下的降解率;反应温度、O₃流量、放电功率的增加,DPCP降解率上升;初始浓度增加,DPCP降解率下降;氧气流量和放电室压力增加,DPCP降解率先上升,后下降。在最佳反应条件下,50 mg/L的DPCP处理16 min降解率达到98%,矿化率40.1%。     

Decomposition of gas phase 1,3-butadiene by ultraviolet/ozone process

A pilot-scale plug-flow reactor was built to investigate its performance in treating airborne 1,3-butadiene (BD) via ozonation (O3) and ultraviolet (UV)/O3 technologies. Governing factors, such as the initial molar ratio of ozone to BD, UV volumetric electric input power, and moisture content in the influent airstream, were investigated. Experiments were conducted at an influent BD concentration of approximately 50 ppm, an ambient temperature of 26 degrees C, and a gas retention time of 85 sec. Results show that an initial molar ratio of ozone to BD of 3.5 and 2 sufficed to obtain BD decompositions of >90% for ozonation and UV/O3, respectively. The UV irradiance did not directly promote the decomposition of BD, rather, it played a role in promoting the production of secondary oxidants, such as hydroxyl radicals. Kinetic analyses indicate that both types of BD decomposition are peudo-first-order with respect to BD concentrations. Moisture content (relative humidity = 40-99%) and UV volumetric electric input power (0.147 and 0.294 W/L) are both factors that weakly affect the rate of BD decomposition. Economic evaluation factors, including both energy of ozone production and UV electric input power, were also estimated.     

气相沿面放电—活性炭纤维吸附联合降解双酚A废水研究

利用气相沿面放电—活性炭纤维(ACF)吸附(简称放电—吸附)联合处理含双酚A(BPA)废水,探讨了联合处理对BPA的降解效果,并通过处理过程中O3利用率变化以及处理前后ACF的表观状态变化分析了反应的作用机制。结果表明,放电—吸附联合处理相比单独放电和单独ACF吸附能显著提高BPA的降解率;在一定范围内,加大放电电压能提高放电—吸附联合处理的BPA降解效果,但放电电压超过一定值后,放电产生的O3量进一步增多,对ACF表面的结构破坏作用增加,反而导致BPA的降解效果降低,本研究较佳的放电电压为8.5kV;扫描电镜分析结果表明,经放电—吸附联合处理后,ACF表面出现大量的孔道,提高了表面的BPA富集浓度,同时也增加反应的活性位点;傅里叶变换红外光谱分析结果表明,联合处理后ACF表面的C—O、C=C、O—H等官能团都有所减少,可能是联合处理过程中O3等活性物质与ACF表面的这些还原性官能团发生了反应,诱导O3分解出了更多的自由基,从而促进了BPA的降解。     

Efficacy of in-situ for the remediation of PAH contaminated soils

Polycyclic aromatic hydrocarbons (PAHs) are of environmental concern because many PAHs are either carcinogens or potential carcinogens. Petroleum products are a major source of PAHs. The occurrence of PAH contamination is widespread and novel treatment technologies for the remediation of contaminated soils are necessary.Ozone has been found to be extremely useful for the degradation of PAHs in soils. For these compounds, the reaction with molecular ozone appears to be the more important degradation pathway. Greater than 95% removal of phenanthrene was achieved with an ozonation time of 2.3 h at an ozone flux of 250 mg h⁻¹. After 4.0 h of treatment at an ozone flux of 600 mg h⁻¹, 91 % of the pyrene was removed. We have also found that the more hydrophobic PAHs (e.g. chrysene) react more slowly than would be expected on the basis of their reactivity with ozone, suggesting that partitioning of the contaminant into soil organic matter may reduce the reactivity of the compound. Even so, after 4 h of exposure to ozone, the chrysene concentration in a contaminated Metea soil was reduced from 100 to 50 mg kg⁻¹ .Ozone has been found to be readily transported through columns packed with a number of geological materials, including Ottawa sand, Metea soil, Borden aquifer material and Wurtsmith aquifer material. All of these geological materials exerted a limited (finite) ozone demand, i.e. the rate of ozone degradation in soil columns is very slow after the ozone demand is met. Moisture content was found to increase the ozone demand, most likely owing to the dissolution of gaseous ozone into the pore water. As once the initial ozone demand is met, little degradation of ozone is observed, it should be possible to achieve ozone penetration to a considerable distance away from the injection well, suggesting that in-situ ozonation is a feasible means of treating uncontaminated unsaturated soils. This is substantiated by two field studies where in-situ ozonation was apparently successful at remediating the sites.     

A simple semi-empirical photochemical model for the simulation of ozone concentration in the Seoul metropolitan area in Korea

O₃ concentrations were simulated over the Seoul metropolitan area in Korea using a simple semi-empirical reaction (SEGRS) model which consists of generic reaction set (GRS), photochemical reaction set, and the diagnostic wind field generation model. The aggregated VOC emission strength was empirically scaled by the comparison of the simulated slope of (O₃–2NO–NO₂) concentration as a function of cumulative actinic light flux against measurements on high surface ozone concentration days with the relatively weak easterly geostrophic winds at the 850 hPa level in summer when the effect of horizontal advection was fairly small. The results indicated that the spatial distribution patterns and temporal variations of spatially averaged ground-level ozone concentrations were quite well simulated compared with those of observations with the modified volatile organic compound (VOC) emission strength. The diurnal trend of the surface ozone concentration and the maximum concentration compared observations were also quite reasonably simulated. However, the maximum ozone concentration occurring time at Seoul lagged about 2 h and the ozone concentration in the suburban area was slightly overestimated in the afternoon due to the influx of high ozone concentration from the urban area. It was found that the SEGRS model could be effectively used to simulate or predict the ground-level ozone concentration reasonably well without heavy computational cost provided the emission of ozone precursors are given.     

Photochemical oxidant pollution and vegetation: effects of mixtures of gases, fog and particles

Photochemical 'smog' contains mixtures of gases (e.g. ozone, nitrogen dioxide), and dry particles (e.g. nitrates). Intermittent fog in the same geographical area can be acidic with high concentrations of nitric acid. Results from recent field studies in the Los Angeles Basin have emphasized the relative toxicity of these components of photochemical air pollution. Studies have focused on gaseous+fog or gaseous+dry particulate effects on conifers, gaseous+fog effects on crops, and the effects of trace pollutants produced during generation of ozone on crops. Data from these studies indicate that direct alterations in growth and physiological responses were observed only with gaseous pollutants (primarily ozone), or repeated applications of highly acidic fogs (pH < 2.7). Direct particle dry deposition effects are unclear. Few interactions have been found between gaseous pollutants and acidic fog. Charcoal-filtered open-top chambers are highly effective in removing pollutants in the following order: fog (100%) > peroxyacetyl nitrate > ozone > nitrogen dioxide > sulfur dioxide > nitrate ion > ammonium ion > sulfate ion. However, nitric oxide concentrations are higher in charcoal-filtered chambers than in ambient air. The studies point out the importance of considering other components of photochemical pollution in addition to ozone, especially when investigating subtle, long-term effects on vegetation.     

Sub-canopy deposition of ozone in a stand of cutleaf coneflower

Although there has been a great deal of research on ozone, interest in exposure of native, herbaceous species is relatively recent and it is still not clear what role the pollutant has in their ecological fitness. The ozone exposure of a plant is usually expressed in terms of the concentration above the canopy or as a time-weighted index. However, to understand the physiological effects of ozone it is necessary to quantify the ozone flux to individual leaves as they develop, which requires knowing the deposition velocity and concentration of the pollutant as a function of height throughout the plant canopy. We used a high-order closure model of sub-canopy turbulence to estimate ozone profiles in stands of cutleaf coneflower (Rudbeckia laciniata L.) located in the Great Smoky Mountains National Park, USA. The model was run for periods coinciding with a short field study, during which we measured vertical concentration profiles of ozone along with measurements of atmospheric turbulence and other meteorological and plant variables. Predictions of ozone profiles by the model are compared with observations throughout the canopy.