低温等离子体-生物法处理硫化氢气体研究

采用低温等离子体-生物法处理硫化氢恶臭气体,硫化氢的去除效率比单独等离子体提高83.4%~90.1%,而且可消除等离子体氧化硫化氢产生的二氧化硫等二次污染物,将其转化为硫酸根和水.采用PCR-DGGE技术研究低温等离子体臭氧对处理硫化氢恶臭气体的生物滴滤塔内微生物群落结构变化规律.结果表明,低温等离子体臭氧影响生物滴滤塔内微生物群落结构,会导致一部分菌群消失,同时产生一些新的菌群;塔内微生物由8个菌种变为9个菌种,3个脱硫作用的硫杆菌菌群消失,出现4个分别具有脱硫作用和嗜酸性的新菌种,5个分别具有脱硫和硫酸盐还原菌种不变.低温等离子体-生物法系统生物滴滤塔内主要有硫杆菌属(Uncultured Thiobacillus sp.,Acidithiobacillus thiooxidans strain dfI,Uncultured Thiobacillus sp.,Uncultured Acidiphilium sp.),黄单胞菌属(Uncultured Xanthomonadaceae bacterium clone SBLE6C12),δ-变形菌(Unculturedδ-Proteobacterium)及副球菌属(Paracraurococcus sp.1PNM-27).     

Ultrasound enhanced heterogeneous activation of peroxydisulfate by bimetallic Fe-Co/GAC catalyst for the degradation of Acid Orange 7 in water

Bimetallic Fe-Co/GAC （granular activated carbon） was prepared and used as heterogeneous catalyst in the ultrasound enhanced heterogeneous activation of peroxydisulfate （PS, S2O8 2-） process. The effect of initial pH, PS concentration, catalyst addition and stirring rate on the decolorization of Acid Orange 7 （AO7） was investigated. The results showed that the decolorization efficiency increased with an increase in PS concentration from 0.3 to 0.5 g/L and an increase in catalyst amount from 0.5 to 0.8 g/L. But further increase in PS concentration and catalyst addition would result in an unpronounced increase in decolorization efficiency. In the range of 300 to 900 r/min, stirring rate had little effect on AO7 decolorization. The catalyst stability was evaluated by measuring decolorization efficiency for four successive cycles.     

宏量和微量元素在炉内喷钙脱硫过程中的作用

研究添加粉煤灰对脱硫过程的作用,实验在滴管炉上进行,温度为１２００℃,结果表明,一些宏量元素的金属氧化物对脱硫过程具有催化作用,但这种催化作用随Ｆｅ２Ｏ３掺加量的改变而变化,先升高后降低,有一个最佳值;一些微量元素的金属氧化物对脱硫过程更强的催化氧化作用,当ＭｎＯ２的掺加量为３％时,充效率提高近１倍。     

改性TiO2对废水处理光催化效率的影响研究进展

TiO2材料在紫外光照射下对废水中的有机物具有光催化降解作用,在环境保护污染治理方面有着广阔的应用前景,但其催化效率并不理想。本文介绍了材料TiO2光催化在废水处理中的研究现状,指出了限制TiO2光催化效率的影响因素,并综述了如何提高其光催化效率的几种途径。     

Ceo2/ACFP催化剂低温选择性催化还原NO

采用介质阻挡放电低温氧等离子体技术进行表面改性的活性碳纤维（ACFP）为载体,进行CeO2／ACFP催化剂低温选择性催化还原（SCR）NO的研究。实验结果表明,ACF先经过低温氧等离子体技术进行表面改性后再负载CeO2,能明显提高对NO的去除率。在NO体积分数为1×10^-3、NH3体积分数为2×10^-3、O2体积分数为5％、Ar作为平衡气、反应温度为120—240℃的条件下,较理想的CeO2负载量（质量分数）为9％;在180℃用9％CeO2／ACFP为催化剂时,NO去除率为86．01％。     

Comparative study of degradation of toluene and methyl isobutyl ketone (MIBK) in aqueous solution by pulsed corona discharge plasma

Effectiveness of pulsed power plasma for the degradation of two toxic volatile organic compounds (VOCs), toluene and methyl isobutyl ketone (MIBK), in aqueous solution was evaluated. The plasma degradation of MIBK has been studied for the first time. The influence of initial concentration of target compound, solution pH and scavengers on percentage degradation was evaluated. 100% removal of 200 mg/L of toluene and MIBK was achieved both in liquid and gaseous phases after 12 and 16 min of plasma treatment, respectively. The first order rate constant of toluene and MIBK degradation (for 200 mg/L each) was 0.421 and 0.319 min^?1 respectively when they were treated individually, and these values decreased slightly during degradation of their mixture. MIBK degradation was slower than toluene and it might be due to semi volatile and hydrophilic nature of MIBK. The effect of initial concentration of toluene and MIBK showed different degradation patterns. Highest degradation of both the compounds was obtained in neutral pH and in absence of scavengers. ?OH radical was the major reactive species involved in their degradation. Their degradation in real environmental matrices showed that removal reduced significantly in secondary effluent due to scavenging of reactive species by various ions and organic matter. The total number of degradation intermediates identified in case of toluene and MIBK was 11 and 14 respectively and formate was the one recalcitrant byproduct generated. The degradation pathway of toluene and MIBK involving reactions of reactive oxygen and nitrogen species and reductive species is proposed.     

非平衡等离子体联合技术降解甲苯气体

采用了自制的纳米钛酸钡基介电材料作为催化剂,以电工陶瓷拉西环作为载体,利用介质阻挡放电产生的非平衡态等离子体对常压下流动态含甲苯的空气进行处理,研究了电场强度、流速、初始浓度及不同填料情况下甲苯的降解及臭氧产生情况,初步探讨了等离子体催化降解甲苯的机理,并进行了产物分析.实验结果表明,电场强度小于13kV·cm-1时,甲苯降解率和臭氧产生浓度随电场强度的提高而上升,随气速和初始浓度的增加而降低;不同填料下降解率及臭氧浓度由大到小排序为有催化剂填料、普通填料、无填料,有催化剂存在时(电场强度为14kV·cm-1,流速为0.3 m3·h-1,甲苯浓度为600 mg·L-1),甲苯降解率最高可达95%.当电场强度>13kV·cm-1时,臭氧浓度因受到过量的高能电子攻击而发生分解.表现为臭氧浓度随电场强度的继续增加而降低.因此,电场强度为13kV·cm-1时,产生的臭氧浓度最高.     

填充床放电等离子体反应器对铜绿微囊藻的生长抑制

研究了放电等离子体反应器中气量和填加固体玻璃球介质对铜绿微囊藻生长抑制和过氧化氢产量、能量与pH对藻生长抑制,以及填充床反应器对藻叶绿素a和细胞数的影响.结果表明,气量的增加和玻璃球介质的填加虽然提高了放电等离子体反应器处理当天对藻生长抑制的效果,但作用不明显;而随着处理后放置培养时间的增加,藻的光密度先略微增加后显著下降,在气量为0.75 m3/h的填充床放电等离子体反应器中,处理40 min后的样品在放置培养到第5 d时,藻的光密度去除率达到了87.3%;过氧化氢产量也随气量的增加和玻璃球介质的填加而得到提高,尤其是固体玻璃球介质的填加使得放电40 min时(气量为0.75 m3/h),过氧化氢的浓度即从无添加玻璃球介质时的4.6μmol/L提高到了38.3μmol/L,进而提高系统在处理后放置培养过程中过氧化氢对藻的破坏作用;向填充床放电等离子体反应器注入的能量越大,藻生长抑制的效果越明显;弱碱性处理条件对藻生长抑制的作用比弱酸性明显,且酸性溶液在处理当天pH升高,碱性溶液降低,但在放置培养期间均趋于中性;该填充床反应器对藻叶绿素a浓度和细胞数的去除效果显著,在处理40 min后放置培养的第5 d,叶绿素a浓度和细胞数去除率全部达到100%.     

微波消解电感耦合等离子体质谱法测定土壤中稀土金属元素

建立了一种电感耦合等离子体质谱测定土壤中微量稀土金属的方法.分析了土壤标准样品中的微量稀土元素,结果与标准值一致.土壤实际样品分析也得到可靠结果.该方法样品采用微波溶样,灵敏度高,是一种比较可靠的微量稀土元素分析新方法.     

大气压降膜DBD等离子体去除废水中四环素

水体中抗生素类药物污染主要来源于人体和动物的大量使用,为改善水环境,降低和去除水中抗生素类药物,设计了可进行较大体积水中四环素的有效去除大气压降膜介质阻挡放电(dielectric barrier discharge)装置,研究了等离子体对四环素模拟液的降解特性,并分析了其降解机理。结果表明,当初始浓度为100 mg·L⁻¹,等离子体处理四环素溶液10 min,去除率为90%,化学需氧量去除率为45%,能量效率达到3.16 g·(kWh)⁻¹。较高的能量效率源自放电产生大量的活性物种(高能电子、离子、自由基等)。采用紫外可见分光光度法和液相色谱-质谱等检测方法对水样进行了分析,当等离子体放电处理2 min后,四环素溶液中开始生成新的物质,随着放电时间的延长,新物质种类和产量也随之逐渐增加,直至水中四环素接近完全降解。研究结果为实现大面积、工业级的有机抗生素废水的处理,保护水生生态环境提供了参考。