膨润土的羟基铝改性及对染料工业废水的处理研究

通过对膨润土的羟基铝改性实验大大提高了膨润土对染料废水的处理效率。实验结果表明:改性膨润土对变色酸有很好的去除效果,对H酸有较好的去除效果,对T酸处理效果一般,对吐氏酸几乎没有效果。     

汶川地震极重灾区地形起伏度特征及其与生态环境受损关联分析

采用DEM数据对汶川地震极重灾区地形起伏度特征分析,海拔高度和地形起伏度总体上是南西高,北东低。5km×5km单元地形起伏度〉1000m的区域面积占27．98％。0．5km×0．5km单元〉100m的区域面积占50．63％。在8．0级主震和6．4级余震震中之间典型区段剖面0．5km间隔分析中,南西段起伏度大于北东段,南西段起伏度〉200m区段占全段14．84％,北东段仅占6．64％。地震导致生态环境受损程度的差异与地形起伏度的差异在空间分布上有一定的重合,具有高起伏度的南西段生态系统破坏面积占总破坏面积的88．55％,新增水土流失面积占新增总面积的70．99％。地震灾区地形起伏度是生态环境遭受严重破坏致灾关联因素之一。     

德阳市旅游特色及其开发对策

以德阳市旅游资源为研究对象,进行了旅游资源评价,并剖析了旅游产业发展过程中出现的问题,提出了具体对策。     

Atrazine sorption-desorption hysteresis by sugarcane mulch residue

Sorption and desorption kinetics are essential components for modeling the movement and retention of applied agricultural chemicals in soils and the fraction of chemicals susceptible to runoff. In this study, we investigated the retention characteristics of sugarcane (Saccharum spp. hybrid) mulch residue for atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine) based on studies of sorption-desorption kinetics. A sorption kinetic batch method was used to quantify retention of the mulch residue for a wide range of atrazine concentrations and reaction times. Desorption was performed following 504 h of sorption using successive dilutions, followed by methanol extraction. Atrazine retention by the mulch residue was well described using a linear model where the partitioning coefficient (K(d)) increased with reaction time from 10.40 to 23.4 cm3 g(-1) after 2 and 504 h, respectively. Values for mulch residue K(d) were an order of magnitude higher than those found for Commerce silt loam (fine-silty, mixed, superactive, nonacid, thermic Fluvaquentic Endoaquepts) where the sugarcane crop was grown. A kinetic multireaction model was successful in describing sorption behavior with reaction time. The model was equally successful in describing observed hysteretic atrazine behavior during desorption for all input concentrations. The model was concentration independent where one set of model parameters, which was derived from all batch results, was valid for the entire atrazine concentration range. Average atrazine recovery following six successive desorption steps were 63.67 +/- 4.38% of the amount adsorbed. Moreover, a hysteresis coefficient based on the difference in the area between sorption and desorption isotherms was capable of quantifying hysteresis of desorption isotherms.     

Performance and microbial community of a membrane bioreactor system——Treating wastewater from ethanol fermentation of food waste

In this study, a lab-scale biological anaerobic/anaerobic/anoxic/membrane bioreactor(A_-~3MBR) was designed to treat wastewater from the ethanol fermentation of food waste,a promising way for the disposal of food waste and reclamation of resources. The 454 pyrosequencing technique was used to investigate the composition of the microbial community in the treatment system. The system yielded a stable effluent concentration of chemical oxygen demand(202 ± 23 mg/L), total nitrogen(62.1 ± 7.1 mg/L), ammonia(0.3 ±0.13 mg/L) and total phosphorus(8.3 ± 0.9 mg/L), and the reactors played different roles in specific pollutant removal. The exploration of the microbial community in the system revealed that:(1) the microbial diversity of anaerobic reactors A_1 and A_2, in which organic pollutants were massively degraded, was much higher than that in anoxic A_3 and aerobic MBR;(2) although the community composition in each reactor was quite different, bacteria assigned to the classes Clostridia, Bacteroidia, and Synergistia were important and common microorganisms for organic pollutant degradation in the anaerobic units, and bacteria from Alphaproteobacteria and Betaproteobacteria were the dominant microbial population in A_3 and MBR;(3) the taxon identification indicated that Arcobacter in the anaerobic reactors and Thauera in the anoxic reactor were two representative genera in the biological process. Our results proved that the biological A_-~3MBR process is an alternative technique for treating wastewater from food waste.     

有机膨润土吸附苯酚的性能及其在水处理中的应用初探

分别用氯化十六烷基吡啶（CPC）和溴化十六烷基三甲铵（CTMAB）改性膨润土,试验了制备有机膨润土的适宜条件及其对吸附苯酚性能的影响。上述两种有机膨润土吸附水中苯酚很快能达到平衡。pH值为3─9时,有机膨润土处理苯酚的效果基本一致;pH>11时,有较高的去除率。CPC－膨润土或CTMAB－膨润土对苯酚的饱和吸附容量分别为103.5mg/g和75.0mg/g。有机膨润土处理苯酚的效果比原土提高8倍以上。     

新型低温Fe/AC脱硫剂的研究

将活性焦担载氧化铁制得Fe/AC脱硫剂用于烟气脱硫,在最经济的烟气脱硫温度窗口(120℃～250℃)显示出高的脱硫活性.考察操作条件对其脱硫活性的影响,并借助EXAFS和TPD表征技术对其内在原因进行探讨.Fe/AC脱硫剂在排烟温度下用于脱硫,其活性明显优于活性焦和纯Fe₂O₃,且载体炭无氧化烧损.Fe/AC吸硫后形成2种含硫物质:H₂SO₄和Fe₂(SO₄)₃,H₂O和O₂的存在可增加Fe/AC对SO₂的吸附硫容.由高比表面活性焦制得的Fe/AC有更高的脱硫活性,这源于活性组分Fe₂O₃在其上良好的分散性.Fe/AC用于脱硫应在适宜空速[(800L/(kg·h)]下操作.     

UASB反应器厌氧氨氧化菌的脱氮特性研究

研究UASB厌氧氨氧化（ANAMMOX）反应器运行情况,采用普通城市污水厂活性污泥接种,人工合成废水,pH值在7.4～7.8之间,温度控制在(32±1)℃。在反应器稳定运行270～450 d之间的180 d中,对NH⁺₄-N和NO^-₂-N去除率均达到99.9％以上,总氮去除率保持在90％以上,NO^-₃-N产生量在20～30 mg/L之间波动。研究表明,UASB厌氧氨氧化反应器处理废水效果明显,对NH⁺₄-N、NO^-₂-N和TN去除率高,NO^-₂-N和NH⁺₄-N比值可以指示厌氧氨氧化反应器性能的演变。UASB反应器稳定运行阶段容积负荷的影响较小,ANAMMOX菌对合成废水适应性强,反应器抗冲击能力较强,受冲击后恢复迅速。出水pH值稳定在8.5附近,pH值变化情况可作为反应器运行状况的指示。关键词硝化厌氧氨氧化上流式厌氧污泥床生物脱氮     

Cadmium uptake by different rice genotypes that produce white or dark grains

IntroductionCadmium(Cd)isanon essentialtracemetalthathasadverseeffectsonplants,animalsandhumans.EnvironmentalcontaminationwithCdduetoanthropogenicactivities,suchasmining,industry,agricultureandwastedisposalhasbeenincreasingsincethebeginningofthe 2 0thcentury (Alloway,1995) .ResearchoncontrollingCdpollutionassociatedwithassessingandmanagingacuteinjurytohumanhealththroughoccupationalexposureanddisposalofCdfromindustrialpointsourcestolocalpopulationsthroughseveralpathwayshasmadeconsiderableadva…     

丰沛铜地氟病区大气环境中氟的分布

利用石灰滤纸法和滤膜电极法测试了徐州丰沛铜地区大气环境中的氟含量,结果表明：由城区至城效到农村,大气环境中的氟含量趋向下降,采煤、煤的燃烧和铝厂等企业是大气中氟的主要污染源,该区地氟病与大气环境中的氟含量未见明显联系,不属燃煤污染型