改性活性炭对废水中甲醛的吸附研究

通过浸渍-焙烧的方法制得铁改性活性炭,并将之应用于废水中甲醛的吸附.分别考察了吸附时间、初始溶液质量浓度、吸附剂投加量对改性活性炭吸附甲醛效果的影响,并研究了铁改性活性炭对甲醛水溶液的等温吸附及动力学.结果表明:在25℃、活性炭投加量为10 g/L、吸附时间为360 min时,铁改性活性炭对甲醛的去除率为91.8％;用准一级、准二级及内扩散动力学模型拟合吸附过程,准二级动力学模型符合该吸附过程;用Langmuir和Freundlich模型描述等温吸附过程,该吸附过程服从Langmuir模型,饱和吸附量为3.396 7mg/g.     

新型风幕控尘除尘机除尘系统数值模拟

针对以往风幕存在不能全断面封闭掘进工作面的问题,设计了一种240°弧形风幕控尘除尘机除尘系统,利用流体力学计算软件Fluent对此系统的风幕宽度、除尘机压力、风幕与吸尘口距离和除尘效果进行了模拟.结果表明:当局扇提供的风量为280 m3/min,风幕宽度为50mm时,抗扩散能力较弱,风幕宽度为100 mm时,风幕风速分布较均匀,抗扩散能力较强,风幕宽度选取150 mm时,末速度达不到阻尘的作用;在风幕宽度为100 mm、风幕距除尘机吸尘口2.4 m的条件下,除尘机压力为-400 Pa和-500 Pa时,不利于粉尘的排出,除尘机压力为-250 Pa和-350 Pa时除尘效果较好;在风幕宽度为100nn、除尘机压力为-350 Pa的条件下,风幕距除尘机吸尘口距离小于2.0m时,不利于粉尘的排出,间距大于2.4m时除尘效果良好;当风幕宽度为100 mm、风幕与吸尘口间距2.4m时,除尘机压力-350 Pa比-250 Pa更有利于粉尘的排出.研究表明,240°弧形风幕控尘除尘机除尘系统在合理的工况参数下除尘效果更好.     

高效降解青霉素菌的筛选鉴定及降解效果研究

从哈尔滨制药总厂的青霉素发酵药渣中富集筛选出6株青霉素耐受菌株,经驯化后,采用高效液相色谱法检验其对青霉素的降解效率,经比较得到一株青霉素高效降解菌株,编号为JZ6。青霉素浓度300 mg/L,30℃,p H6.7,121 r/min条件下恒温震荡培养24 h后,在青霉素做唯一碳源情况下,青霉素几乎不被降解,外加碳氮源后降解率可达到99.98%。对其进行电镜扫描和16SrDNA序列分析,鉴定其属于洋葱伯克霍尔德菌属(Burkholderia cenocepacia),16SrDNA序列长度为1451bp,在Gen Bank登录号为KF826288。     

Cobalt and sulfur co-doped nano-size TiO2 for photodegradation of various dyes and phenol

Various compositions of cobalt and sulfur co-doped titania nano-photocatalyst are synthesized via sol–gel method. A number of techniques including X-ray diffraction(XRD), ultraviolet–visible(UV–Vis), Rutherford backscattering spectrometry(RBS), thermal gravimetric analysis(TGA)Raman, N2 sorption, electron microscopy are used to examine composition, crystalline phase, morphology, distribution of dopants, surface area and optical properties o synthesized materials. The synthesized materials consisted of quasispherical nanoparticles of anatase phase exhibiting a high surface area and homogeneous distribution o dopants. Cobalt and sulfur co-doped titania demonstrated remarkable structural and optical properties leading to an efficient photocatalytic activity for degradation of dyes and phenol under visible light irradiations. Moreover, the effect of dye concentration catalyst dose and p H on photodegradation behavior of environmental pollutants and recyclability of the catalyst is also examined to optimize the activity of nano-photocatalys and gain a better understanding of the process.     

Preparation and evaluation of aminopropyl-functionalized manganese-loaded SBA-15 for copper removal from aqueous solution

A novel material, aminopropyl-functionalized manganese-loaded SBA-15 (NH₂-Mn-SBA-15), was synthesized by bonding 3-aminopropyl trimethoxysilane (APTMS) onto manganese-loaded SBA-15 (Mn-SBA-15) and used as a Cu^2 + adsorbent in aqueous solution. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction spectra (XRD), N₂ adsorption/desorption isotherms, high resolution field emission scanning electron microscopy (FESEM) and X-ray photoelectron spectroscopy (XPS) were used to characterize the NH₂-Mn-SBA-15. The ordered mesoporous structure of SBA-15 was remained after modification. The manganese oxides were mainly loaded on the internal surface of the pore channels while the aminopropyl groups were mainly anchored on the external surface of SBA-15. The adsorption of Cu^2 + on NH₂-Mn-SBA-15 was fitted well by the Langmuir equation and the maximum adsorption capacity of NH₂-Mn-SBA-15 for Cu^2 + was over two times higher than that of Mn-SBA-15 under the same conditions. The Elovich equation gave a good fit for the adsorption process of Cu^2 + by NH₂-Mn-SBA-15 and Mn-SBA-15. Both the loaded manganese oxides and the anchored aminopropyl groups were found to contribute to the uptake of Cu^2 +. The NH₂-Mn-SBA-15 showed high selectivity for copper ions. Consecutive adsorption–desorption experiments showed that the NH₂-Mn-SBA-15 could be regenerated by acid treatment without altering its properties.     

镜泊湖流域浮游植物群落及其功能类群的时空演替特征研究

为了解镜泊湖流域浮游植物群落的时空变化特征,于2013年对镜泊湖流域进行了采样调查.共检测出浮游植物7门81种(属),以硅藻和绿藻为主,分属17个功能类群.时间上,春季浮游植物丰度、叶绿素含量和功能类群丰度均高于秋季.空间上,春季镜泊湖流域浮游植物丰度和叶绿素含量湖泊区＞汇水区＞出水区,秋季汇水区＞湖泊区＞出水区.多维尺度分析表明,镜泊湖流域不同区域之间浮游植物群落组成存在显著的空间差异.     

双甘膦废水处理技术研究

双甘膦废水中含有高浓度总磷、有机磷、甲醛、氰化物、氨氮、COD,运用三效蒸发＋强氧化＋两级化学除磷＋UASB＋兼氧＋好氧组合处理双甘膦废水。研究结果表明双甘膦废水排放满足《污水综合排放标准》（G88978—1996）二级排放标准。     

熏蒸废水一体化处理工艺分析研究——以四川某生物防治公司为例

四川某生物防治公司在利用磷化氢与二氧化碳混合气体熏蒸处理烟草和粮食杀菌生产过程中产生少量废水。废水主要含氢氧化铝等固体废物,具有产生量小、SS浓度大、颗粒物粒径极小、色度大、溢出气含腐蚀性等特点,对客户感官产生不适。结合该公司实例介绍了以"沉淀+一体化负压两级过滤"为主体的处理工艺的熏蒸废水处理过程。经过处理,该公司生产废水中SS和色度去除率可达到99.3%与98.1%,出水可满足相关标准与相应感官要求。     

Intermittently aerated EMMC-Biobarrel (entrapped mixed microbial cell with Bio-barrel) process for concurrent organic and nitrogen removal

The PEMMC-Biobarrel (packed-bed of entrapped mixed microbial cells with Bio-barrel) process and MEMMC-Biobarrel (moving EMMC-Biobarrel) process were investigated for enhancing concurrent organic and nitrogen removal with applied intermittent aeration. For the PEMMC-Biobarrel process, the EMMC-Biobarrel carriers were employed at a packing ratio of 20%. In the MEMMC-Biobarrel process, the EMMC-Biobarrel carriers with a packing ratio of 10% were added along with the activated sludge (AS) in the bioreactor. Three different hydraulic retention times (HRTs) of 9, 6 and 4 h were applied. Aeration was provided intermittently at time schedules of 1 h air on/1 h air off, 1 h on/1.5 h off and 1 h on/2 h off. Nitrogen removal in the PEMMC-Biobarrel system was not improved by increasing the intermittent non-aeration time period. On the other hand, the MEMMC-Biobarrel process enhanced nitrogen removal with increasing non-aeration time even though the SCOD/N(TIN) ratio decreased from 6 to 4. Significant denitrification during the aeration cycle was observed in the MEMMC-Biobarrel process. The MEMMC-Biobarrel process demonstrated the most efficient organic and nitrogen removal at an HRT of 6 h with an intermittent aeration time schedule of 1 h on/2 h off. Nitrogen removal of 80% was achieved, which was about 15% higher compared to the AS system. TCOD and SCOD removal efficiencies were 80% and 75%, respectively.     

Alcohol-impaired driving and its consequences in the United States: the past 25 years

INTRODUCTION: Progress in dealing with the alcohol-impaired driving problem in the United States during the past 25 years is addressed. METHODS: Trends in various measures of the problem were tracked and a thorough review of the relevant literature conducted. RESULTS: In the 1980s and continuing into the early 1990s, major decreases occurred in alcohol-impaired driving and its consequences. The contribution of alcohol to fatal crashes dropped by 35-40% during this period. Two primary reasons for the decline appear to be the emergence of citizen activist groups that mobilized public support and attention to the problem, and the proliferation of effective laws. Since about 1995 the alcohol-impaired driving problem has stabilized at a reduced but still quite high level. CONCLUSIONS: Highway safety organizations and citizen activist groups have continued to highlight the problem, but its status as a social issue has diminished. We basically know what the primary target groups are, and we know measures that would work to reduce the problem if implemented more fully. We know that political leadership, state task forces, and media advocacy are important ingredients in addressing the problem. It is likely that a resurgence in citizen activism will be necessary to foster these elements and refocus the nation on the unfinished battle against alcohol-impaired driving. IMPACT ON INDUSTRY: Alcohol-impaired driving is still a major problem that needs continuing attention.