远程氮等离子体改性活性炭纤维及其吸附性能研究

采用远程等离子体方法对活性炭纤维(ACF)进行表面功能化改性。研究了放电参数(放电时间、氮气压力、放电功率)与远程位置对ACF减重率及吸附性能的影响。结果表明,远程氮等离子体中的电子、离子对试样的刻蚀作用被抑制,远程等离子体改性后的ACF比未改性的ACF以及放电区的吸附剂对结晶紫的去除效果要好。ACF经过远程氮等离子体改性后,表面出现羧基,增加了其表面酸性含氧官能团,从而增强了对碱性染料结晶紫的吸附能力。当氮气压力10Pa、放电功率60W、放电时间100s时,在远程区80cm处经改性后的ACF的吸附性能最佳。     

在烷基聚葡糖苷W/O微乳液中Novozym 435脂肪酶催化酯合成反应动力学的研究

研究了Novozym435脂肪酶在烷基聚葡糖苷形成的W／O微乳液体系中,催化正丁醇与正己酸合成酯的反应动力学．反应初始速率V0与正丁醇（ROH）和正己酸（HA）摩尔浓度的比值（CROH^0／CHA^0）有关,在CROH^0／CHA^0=0．2-17范围内,随CROH^0／CHA^0比值减小,初始速率V0增大,尤其是当CROH^0／CHA^0〈3时,V0迅速增大．其原因可能是醇浓度较高时,醇与酶结合形成的死端复合物在较高浓度酸的作用下分解,重新析出游离态酶所致．脂肪酶加入量、水相介质组成和醇的种类等对反应速率有重要影响．     

低温等离子体法处理甲醛气体

报道用低温等离子体的方法去除甲醛气体,主要考察了电场强度、进口浓度及填料对于甲醛气体去除效率的影响。实验研究结果表明,随着电场强度的增加,进口浓度的降低和在反应器中加有填料都会提高甲醛气体的去除效率。低温等离子体方法去除甲醛气体的机理可分为2部分:电子与污染物分子的直接碰撞和电场产生的活性粒子与污染物分子之间发生的一系列化学反应。     

低温等离子体法去除苯和甲苯废气性能研究

对低温等离子体法去除苯和甲苯废气的性能进行了探讨,在理论分析的基础上进行实验研究。低温等离子体法去除苯和甲苯的机理是放电反应产生的高能电子与苯和甲苯分子发生非弹性碰撞并将能量全部或部分传递给目标分子,使其裂解、激化。被裂解、激化的分子与臭氧、活性基团发生一系列物理、化学反应后生成二氧化碳、一氧化碳和水。实验结果表明,苯和甲苯的去除率随着电场强度的增强而增大,随着气体流速的增大而减小。在较高电场强度下,有钛酸钡填料的反应器比无填料的反应器对苯和甲苯的去除率高得多,苯最高去除率可达92 6%,甲苯可达到96 8%。相同条件下甲苯比苯更容易去除。     

Pulsed corona discharge for improving treatability of coking wastewater

Coking wastewater(CW) contains toxic and macromolecular substances that inhibit biological treatment. The refractory compounds remaining in biologically treated coking wastewater(BTCW) provide chemical oxygen demand(COD) and color levels that make it unacceptable for reuse or disposal. Gas-phase pulsed corona discharge(PCD) utilizing mostly hydroxyl radicals and ozone as oxidants was applied to both raw coking wastewater(RCW) and BTCW wastewater as a supplemental treatment. The energy efficiency of COD,phenol, thiocyanate and cyanide degradation by PCD was the subject of the research. The cost-effective removal of intermediate oxidation products with addition of lime was also studied. The energy efficiency of oxidation was inversely proportional to the pulse repetition frequency: lower frequency allows more effective utilization of ozone at longer treatment times. Oxidative treatment of RCW showed the removal of phenol and thiocyanate at 800 pulses per second from 611 to 227 mg/L and from 348 to 86 mg/L, respectively, at 42 k Wh/m~3 delivered energy, with substantial improvement in the BOD5/COD ratio(from 0.14 to 0.43).The COD and color of BTCW were removed by 30% and 93%, respectively, at 20 k Wh/m~3,showing energy efficiency for the PCD treatment exceeding that of conventional ozonation by a factor of 3–4. Application of lime appeared to be an effective supplement to the PCD treatment of RCW, degrading COD by about 28% at an energy input of 28 k Wh/m3 and the lime dose of 3.0 kg/m~3. The improvement of RCW treatability is attributed to the degradation of toxic substances and fragmentation of macromolecular compounds.     

锰钴水滑石/石墨烯电极的制备及催化性能

采用水热法制备了以氧化还原石墨烯（rGO）为载体的锰钴水滑石（LDH）,即MnCo-LDH/rGO复合材料并研究其氧还原性能.在Mn/Co物质的量比为1：3的条件下,MnCo-LDH和MnCo-LDH/rGO的形貌和催化性能最为突出.与MnCo-LDH相比,MnCo-LDH/rGO在Na₂SO₄溶液中的氧化还原峰更加明显（-0.425V）,且峰电流更大,达到0.749mA/cm².将MnCo-LDH/rGO作为阴极,在120min内持续提供30mA/cm²的电流可使浓度为20mg/L的罗丹明B染料（RhB）降解98.6%,具备良好的降解性能.旋转圆盘（RDE）及自由基淬灭实验结果显示,反应中转移电子数为2,且主要自由基为·OH.     

Water chemistry influences on long-term dissolution kinetics of CdSe/ZnS quantum dots

Widespread usage of engineered metallic quantum dots(QDs) within consumer products has evoked a need to assess their fate within environmental systems.QDs are mixed-metal nanocrystals that often include Cd~(2+)which poses a health risk as a nanocrystal or when leached into water.The goal of this work is to study the long-term metal cation leaching behavior and the factors affecting the dissolution processes of mercaptopropionic acid(MPA) capped CdSe/ZnS QDs in aphotic conditions.QD suspensions were prepared in different water conditions,and release of Zn2+and Cd~(2+) cations were monitored over time by size exclusion chromatography-inductively coupled plasm a-mass spectrometry.In most conditions with dissolved 02 present,the ZnS shell degraded fairly rapidly over～1 week,while some of the CdSe core remained up to 80 days.Additional MPA,Zn~(2+),and Cd2+temporarily delayed dissolution,indicating a moderate role for capping agent detachment and mineral solubility.The presence of H_2 O_2 and the ligand ethylenediaminetetraacetate accelerated dissolution,while NOM had no kinetic effect.No dissolution of CdSe core was observed when 02 was absent or when QDs formed aggregates at higher concentrations with 02 present.The shrinking particle model with product layer diffusion control best describes Zn2+and Cd~(2+) dissolution kinetics.The longevity of QDs in their nanocrystal form appears to be partly controlled by environmental conditions,with anoxic,aphotic environments preserving the core mineral phase,and oxidants or complexing ligands promoting shell and core mineral dissolution.     

混合单体对等离子体法改性PTFE膜微生物亲和性能的影响

膜材料氧传质性能和微生物亲和性对MABR（膜曝气生物膜反应器）的稳定运行及处理效果有重要影响,为探究混合单体对等离子体法改性PTFE（聚四氟乙烯）膜微生物亲和性能的影响,采用两步等离子体法分别在PTFE膜表面接枝聚合DOPA（左旋多巴）/GMA（甲基丙烯酸缩水甘油酯）、Lys（赖氨酸）/GMA、BA（苯胺）/GMA和DEA（乙二胺）/GMA四种混合单体,测定改性前、后PTFE膜的微生物亲和性,并进一步确定最佳混合单体改性PTFE膜的氧传质性能.结果表明:与未改性PTFE膜和仅接枝聚合GMA单体改性复合膜相比,DOPA/GMA、Lys/GMA、BA/GMA和DEA/GMA混合单体改性复合膜表面的微生物亲和性均有提高;Lys/GMA混合单体改性复合膜表面的微生物亲和性最佳,显著高于未改性PTFE膜,膜表面的生物量用ρ（DNA）和ρ（TOC）表示,分别为9.67 ng/μL和103.44 mg/L,比未改性PTFE膜高出34.7%和286.0%,同时其膜表面的生物量增加速度最快;DOPA/GMA和DEA/GMA混合单体改性膜表面的微生物亲和性相近,且高于BA/GMA混合单体改性膜;Lys/GMA混合单体改性复合膜的最大氧传质系数为1.17 m/d（操作压力为35 kPa）,显著高于未改性PTFE膜的0.48 m/d（操作压力为11 kPa）.研究显示,两步等离子体法接枝聚合的混合单体改性能够同时改善PTFE膜的微生物亲和性和氧传质性能,更适合于制备MABR复合膜,可为开发MABR专用膜材料提供理论基础和技术支持.      

蜂窝状活性炭研究

蜂窝状活性炭是一种新型的活性炭。简要介绍了蜂窝状活性炭的结构特性和吸附性能，重点总结了蜂窝状活性炭基催化剂的制备方法及其在催化方面的应用。