Gradients of ozone at a forest site and over a field cropconsequences for the AOT40 concept of critical level

Ozone concentrations were measured at a wind-exposed edge of a 60 year-old 15–20 m tall Norway spruce forest in south-west Sweden and simultaneously over a barley field 5 km away for 27 days, At the forest site, measurements were performed at 3 and 13 m height 15 m in front of the forest edge, at 3 m height 15 m into the forest, and at 3 and 13 m height 45 m into the forest. Measurements at 3 m were made with three replicate tubes separated by 10 m. Differences between replicates were small. At 13 m height, the concentration (24-hr-average) 45 m into the forest was 95% of that in front of the forest edge. The average concentration at 3 m height did not vary strongly with the distance into the forest, but was 86% of that at 13 m in front of the forest edge. For AOT40 (Accumulated Exposure Over Threshold 40 ppb ozone), the differences between different positions were larger. At the 13 m level the AOT40 (day and night) was 88% of that in front of the forest 45 m into the forest. The AOT40 at 3 m was 71% of that at 13 m outside the forest. At the crop site, the ozone concentration at 1.1 m (0.1 m above the canopy), was 78% of that at 9 m (06.00–22.00). The AOT40 at 1.1 m above the ground, however, was only 50% of that at 9 m, indicating that serious errors can arise if ozone monitoring data are used uncorrnected in dose-response relationships based on measurements performed at plant height. The ozone concentration for the whole period differed very little between 9 m height at the crop site and 13 m height at the forest site outside the forest during daytime conditions (06.00–22.00). Night-time (22.00–06.00) values were only 21% at the crop site of those at the forest site due to the stronger night inversion development in the agricultural environment compared to the wind exposed forest edge. The results suggest that variations in topography and vegetation are important to consider when combining ozone monitoring data with dose-response functions.     

葡萄在散放条件下低浓度臭氧保鲜效果的研究

通过对散放条件下的葡萄进行低深度的臭氧保鲜实验，以期发现1种安全、无污染、低耗高效、易操作的新的葡萄保鲜方法。     

低温等离子体发生器工作参数优化

低温等离子体（non-thermal plasma,NTP）发生器放电产生的活性物质可有效去除柴油机颗粒捕集器（diesel particular filter,DPF）中沉积的颗粒物（particulate matter,PM）,而发生器的工作参数直接影响活性物质的浓度,选取合适的工作参数有利于活性物质的产生。该文以空气为气源,考察了放电区表面温度、放电电压、放电频率、空气流量4个因素对NTP发生器产生活性物质浓度的影响。以O3质量浓度作为试验指标,进行了正交试验设计,并对试验结果进行单因素影响规律的分析、极差分析以及方差分析。研究表明：较低的放电区表面温度和放电频率有利于O3的生成,O3质量浓度随着空气流量的增大先升高后降低,随放电电压的变化没有明显的增减趋势;放电区表面温度、空气流量为显著因素,放电电压和放电频率为不显著因素;各因素对试验结果影响的大小顺序为：空气流量＞放电区表面温度＞放电频率＞放电电压;NTP反应器产生活性物质的较优组合是：放电区表面温度40℃、放电电压19 kV、放电频率7 kHz、空气流量5 L/min。研究结果对开发用于分解柴油机PM的NTP系统、优化NTP技术再生DPF的研究有重要的指导意义。     

Impact of Elevated Ozone on Nutrient Uptake and Utilization of Chinese Hybrid Indica Rice (Oryza Sativa) Cultivars under Free-Air Ozone Enrichment

To assess the effects of ozone (O₃) on uptake and utilization of nitrogen, phosphorus, and potassium nutrients in rice for planning rational fertilization under projected O₃ elevation. Two hybrid indica cultivars were exposed to ambient and elevated O₃ (E-O₃) under a free-air O₃ enrichment system. E-O₃ differently affected the accumulation and distribution of biomass, and the absorption and distribution of nutrients between cultivars. These effects were related to rice cultivar and nutrient type. E-O₃ led to significantly decreased partial factor productivity and grain production efficiency (GPE) of nitrogen in both cultivars; however, the effects of E-O₃ on GPEs of phosphorus and potassium varied with cultivar. Responses of nutrients harvest indices between cultivars to E-O₃ were adverse. Differences between cultivars and elements should be considered when examining E-O₃ potentially affecting the nutrient dynamics for the purpose of reducing the amount of fertilizer applied in paddy systems to decrease potential environmental pollution.     

Fe2O3-TiO2/UV/O3+PSAF协同处理猪场废水效果及其除碳脱氮机制

为实现低碳高氨氮猪场废水深度除碳脱氮,该研究提出了 Fe_2O_3-TiO_2/UV/O_3+PSAF组合处理工艺技术。应用响应面法确立了组合工艺的最优工况条件,采用三维荧光和紫外-可见吸收光谱分析了有机物的荧光和分子结构变化特征,并结合碳、氮形态变化探明了其协同处理特性及除碳脱氮机制。结果表明,Fe_2O_3-TiO_2投加量为1.06 g/L、O_3流量为3.02 g/h、曝气时间为90.75 min、聚硅酸铝铁(PSAF)用量为833.29 mg/L,COD及NH_(3-)N去除效果最好,试验值与预测值偏差0.75%和0.56%,拟合性良好;组合工艺对猪场废水中的溶解性微生物代谢产物和类腐殖质处理效果显著,溶解性有机碳和总溶解性氮去除率分别达77.7%和82.6%,协同因子分别为1.11和1.50。其中,Fe_2O_(3-)TiO_2/UV/O_3对类腐殖质削减效果显著,O_3和·OH协同氧化类腐殖质、NH_3-N为小分子物质、NO_3~--N和N_2 (N_2转化率达39.71%),提高了富氧官能团的数量,促进了氮素的转化和矿化,利于PSAF对小分子物质和NO_3~--N等污染物的去除,组合工艺协同互补作用明显。研究结果为深度处理低碳高氨氮有机废水提供一种新思路。     

鸡舍中臭氧消毒和除臭效果研究

试验选用200只爱拔益加肉鸡,随机分为A、B两组,分别饲养于A、B两间大小相同的动物房中,A组给予臭氧消毒,B组常规饲养,测定两个鸡舍内空气中细菌总数、鸡粪中大肠杆菌数和鸡舍氨气浓度。试验期38 d。结果表明,空气中细菌总数杀灭率、粪便大肠杆菌杀灭率、氨气降低率随日龄的增长均出现下降趋势,但与B组相比,35日龄时,A组的空气细菌总数、粪便大肠杆菌数和氨气浓度显著降低,分别为30.45%(P<0.05)、23.52%(P<0.05)和28.20%(P<0.01)。     

潮汕地区地面臭氧浓度的变化特征

对潮汕地区汕头、揭阳和潮州市3个代表性的监测点7月份的地面臭氧（O3）浓度进行了监测与评价,并对该地区3市O3的污染状况和O3与NOx、气温和相对湿度的相关性,以及O3浓度变化的特征进行了分析.结果表明,该地区受O3污染程度较轻,3个城市中又以汕头市的受污染程度最轻,其次是潮州市.O3与NOx浓度及其与空气湿度的变化呈负相关,与气温变化呈正相关.高温、低湿的气象条件更利于O3的产生和累积.     

臭氧处理对切分青椒贮藏品质的影响

为了探讨臭氧气体对切分蔬菜贮藏品质的影响,该文以青椒为材料,分别研究了2.14、4.28、6.42和8.56mg/cm3质量浓度臭氧气体处理下切分青椒在5～8℃贮藏条件下的硬度、叶绿素含量、Vc的含量、菌落总数和感官品质的变化。试验结果表明:适当浓度的臭氧处理可显著抑制切分青椒叶绿素含量、Vc含量、感官品质和硬度的下降,并对微生物有明显的杀灭作用;以6.42mg/cm3臭氧质量浓度下处理15min,切分青椒5～8℃下贮藏6d感观评价得分为32分,基本保持了新鲜青椒色、味、香品质;2.14mg/cm3的处理组臭氧浓度过低保鲜效果不明显,8.56mg/cm3的处理组因臭氧浓度过高,贮藏效果低于未处理组。研究结果可为切分蔬菜的保鲜贮藏提供参考。     

臭氧水减菌化处理在炝蟹生产中的应用（简报）

为了达到产品质量控制的目的,通过臭氧水的减菌化处理来减少原料蟹的初始菌.以此提高炝蟹的微生物控制效果.同时运用栅栏技术,阻止微生物的生长发育.原料蟹经自来水清洗后,再用0.7 mg/kg臭氧水喷淋3 mill,用饱和盐水24"C腌制5 h后,进行气调包装(气体配比:CO260%,N240%).试验结果表明:臭氧水能减少原料蟹的初始菌,经臭氧水处理过的蟹,微生物得到了有效的控制;同时,常见致病菌也得到了较好的控制;炝蟹产品符合最新国家卫生标准,且口感舒爽.在-20℃贮藏其保质期达到7个月.     

苹果汁中棒曲霉素臭氧脱毒设备的设计与应用

为了高效降解苹果汁中棒曲霉素,研制了一套利用臭氧技术降解棒曲霉素的设备。该设备利用臭氧的强氧化性,使其与苹果汁充分接触,从而使苹果汁中的棒曲霉素发生氧化分解。以人工污染的苹果汁为试验材料,研究了该设备的脱毒效果及对果汁主要品质指标的影响。研究结果表明:该臭氧脱毒设备能够有效降解苹果汁中的棒曲霉素,且臭氧浓度和臭氧处理时间均显著影响棒曲霉素的降解效果(P0.05)。在果汁棒曲霉素起始浓度约为201.60μg/L,pH值3.5和可溶性固形物质量分数为15%时,用12 mg/L的臭氧在3 L/min流速下处理15 min,可将棒曲霉素减少到约49.24μg/L,降解率达75.58%,达到世界卫生组织(WHO)和英国软饮料协会(British soft drinks association,BSDA)设定的最大允许限量50μg/L的要求。臭氧处理对果汁可溶性固形物含量、pH值和总酸度无显著影响(P0.05),但对果汁透光率、色值、苹果酸和总酚含量影响较大(P0.05)。该设备具有投资小、脱毒效率高、脱毒成本低、环保无污染、结构简单、易操作、适合各种规模的果汁企业等优势,具有良好的经济效益和社会效益。