投加ABS颗粒对MBR膜过滤特性的影响

向膜生物反应器(MBR)中投加ABS颗粒,以干扰膜表面泥饼层的形成和减轻膜污染的发生。结果表明,向MBR中投加粒径为1 mm的ABS颗粒,发现颗粒的最佳投加量为1.5 kg/m3,投加颗粒的膜运行时间是对照实验运行时间的3倍。颗粒对膜表面泥饼沉积层抑制明显,与对照实验泥饼层重量最大相差290 g,颗粒使膜上泥饼层的分布也不同。颗粒的投加也改变了污泥EPS含量,相比对照实验,多糖、蛋白质含量分别提高了17.2%和8%,污泥粘度提高了17.6%。细格栅与颗粒使MBR对TN、TP去除效果分别提高了8.5%和9.7%,对COD的影响不大。     

多相光催化反应器辐射能模型的建立与验证

采用双通量模型模拟了管式三相流化床光催化反应器中辐射能分布和局部体积能量吸收速率,并采用负载型TiO2/SiO2光催化剂进行了实验验证,考察了液相介质、通气量及催化剂浓度对光辐射强度和体积能量吸收速率的影响.实验结果表明,实验数据和模型计算值能够较好吻合,蒸馏水做液相介质时,可将气液鼓泡流看成单一的连续相,催化剂浓度越...     

Removal efficiencies of PCDDs/PCDFs by air pollution control devices in municipal solid waste incinerators

Removal efficiencies of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDDs/PCDFs) by air pollution control devices (APCDs) in the commercial-scale municipal solid waste (MSW) incinerators with a capacity of above 200 ton/day were evaluated. The removal efficiencies of PCDDs/PCDFs were up to 95% when the activated carbon (AC) was injected in front of electrostatic precipitator (EP). Spray dryer absorber/bag filter (SDA/BF) had high removal efficiency (99%)) of PCDDs/PCDFs when a mixture of lime and AC was sprayed into the SDA. When the AC was not added in scrubbing solution, the whole congeners of PCDDs/PCDFs were enriched in the wet scrubber (WS) with negative removal efficiencies of -25% to -5731%. Discharge of PCDDs/PCDFs was decreased with increasing the proportions of AC added in scrubbing solution. Selective catalytic reduction (SCR) system had the removal efficiencies of up to 93% during the test operation.     

西安大气气相中的多环芳烃

利用PUF被动采样器于2008年8月—2009年7月采集了西安大气样品,研究了大气气相中多环芳烃（PAHs）的含量和季节分布特征。结果表明,西安大气气相中16种美国EPA优控的PAHs（Σ16PAHs）质量浓度为10.9-489.6 ng/m3（平均为143.4 ng/m3）,四季具有明显的季节差异,依次为夏季（62.5 ng/m3）〈春季（80.1 ng/m3）〈秋季（175.8 ng/m3）〈冬季（255.2 ng/m3）。气相中PAHs主要以3-4环为主,占总量的86.5%-94.1%。利用主成分分析法判断四季气相中PAHs的污染来源类型,主要为燃煤和机动车尾气及生物质燃烧的复合源。     

GIS支持下的土壤侵蚀量估算——以江西省泰和县灌溪乡为例

在地理信息技术（ＧＩＳ）的支持下,应用通用土壤侵蚀方程（ＵｎｉｖｅｒｓａｌＳｏｉｌＬｏｓｓＥｑｕａｔｉｏｎ,简称ＵＳＬＥ）估算了江西省泰和县灌溪乡的土壤侵蚀量。研究结果表明,当地表覆盖率大于１５％时,计算的结果与实测的数据有良好的相关性（０８７）。     

流域累积效应及其评估中存在问题的探讨

阐述了累积效应、流域累积效应和累积效应评估的概念，并从技术、哲学和社会价值体系3方面着重论述了螺积效应评估存在的问题。通过对流域累积效应评估的研究及未来展望，提出了更加完善合理的流域生态管理思路。     

7种海洋微藻对UV-B辐射的敏感性差异分析

在实验室条件下研究了UV B辐射对 7种海洋微藻生长的影响 .结果表明 :7种微藻的相对增长率随着UV B辐射剂量的增强呈明显的下降趋势 (P <0 0 5 ) .实验微藻对UV B辐射的敏感性符合绿藻 >硅藻 >金藻的分类学规律 ,其中金藻 870 1是最敏感的一种 .叶绿素a和类胡萝卜素的 48h半数有效抑制浓度EC50 远远大于相对增长率的EC50 .分光光度法测定微藻在UV波段的吸收峰集中在UV C波段 .在UV B波段 ,每 10 4 个细胞的最大吸收度的顺序为 :绿藻 >硅藻 >金藻 .微藻对UV B辐射的敏感性可能与其在该波段的吸收度之间存在一致性关系     

遥感技术与陆地生态系统碳循环研究

在人类社会日益关注全球环境问题的今天,大气中CO2和CH4等温室气体浓度升高诱发的全球气候变化已成为可持续发展的最严峻挑战。因此,针对各个陆地生态系统的碳循环研究成为气候变化和区域发展研究的重点和关键。陆地生态系统中土地利用方式、植被种类等的变化,通过时间和空间的尺度来影响着全球碳循环,而遥感技术具有宏观、速度快、周期短、信息量大、多时相等特点,因此在植被覆盖和土地利用分类、碳循环遥感模型等方面都有着重要的应用。     

磁性吸附剂CeO2/MZFS去除水中盐酸四环素

利用废碱性电池制备得到尖晶石结构的锰锌铁氧体Mn_0.6Zn_0.4Fe₂O₄（MZF）,利用原位聚合制备得到硅包覆的磁性纳米复合物MZF@SiO₂（MZFS）,采用浸渍法制备得到集磁分离、吸附与类Fenton催化活性于一体的CeO₂/MZFS磁性吸附剂,并对其形貌和磁性能等进行了表征.结果表明,CeO₂/MZFS对水中盐酸四环素（TH）表现出良好的吸附性能,160 min吸附过程可达平衡,TH的去除率达到95%.吸附过程可用准二级动力学方程描述,化学吸附为速控步骤;Freundlich等温吸附模型能较好地描述该吸附过程,热力学计算结果表明,CeO₂/MZFS对TH的吸附是以物理吸附为主的自发吸热过程;利用红外光谱初步揭示了吸附机制.吸附TH后的CeO₂/MZFS可利用其非均相类Fenton催化活性以H₂O₂作为再生剂进行原位再生,6次循环使用后,CeO₂/MZFS对TH仍能保持较高的平衡吸附量.研究结果可为抗生素废水的治理提供理论指导和技术支持.     

Advanced treatment of dyeing wastewater towards reuse by the combined Fenton oxidation and membrane bioreactor process

The performance of combined Fenton oxidation and membrane bioreactor (MBR) process for the advanced treatment of an effluent from an integrated dyeing wastewater treatment plant was evaluated. The experimental results revealed that under the optimum Fenton oxidation conditions (initial pH 5, H 2 O 2 dosage 17 mmol/L, and Fe 2+ 1.7 mmol/L) the average total organic carbon (TOC) and color removal ratios were 39.3% and 69.5% after 35 min of reaction, respectively. Results from Zahn-Wallens Test also represented that Fenton process was effective to enhance the biodegradability of the test wastewater. As for the further purification of MBR process, TOC removal capacity was examined at different hydraulic retention times (HRT) of 10, 18 and 25 hr. Under the optimum HRT of 18 hr, the average TOC concentration and color of the final MBR effluent were 16.8 mg/L and 2 dilution time, respectively. The sludge yield coefficient was 0.13 g MLSS/g TOC and TOC degradation rate was 0.078 kg TOC/(m 3 ·day). The final effluent of MBR can meet the reuse criteria of urban recycling water-water quality standard for miscellaneous water consumption GBT18920-2002.