植酸掺杂聚苯胺对水中Cr(Ⅵ)的去除研究

为实现对废水中Cr（Ⅵ）的高效去除,利用PA（植酸）掺杂PANI（聚苯胺）制备了一种新型三维多孔吸附剂PANI/PA,探究PA的掺杂浓度、pH、反应时间、反应温度、共存金属离子和无机阴离子对Cr（Ⅵ）去除率的影响.首先,采用SEM、FTIR、XPS等表征手段证实PA成功掺杂到PANI上形成三维多孔结构,并进一步利用吸附动力学、吸附等温线、吸附热力学模型分析PANI/PA对Cr（Ⅵ）的吸附特性.结果表明:①0.05 mol/L PA掺杂的吸附材料具有最优吸附效果.当pH为4.0时,吸附剂可以实现对Cr（Ⅵ）最有效的去除.②吸附动力学符合准二级动力学模型,表明化学吸附是控制反应速率的主要因素.Langmuir等温吸附模型对等温吸附过程实现较准确拟合,在318 K时达最大吸附容量（99.0 mg/g）,优于普通PANI吸附剂.③吸附机理主要是表面静电吸附、络合作用和还原作用.④在其他金属离子和无机阴离子共存下,PANI/PA对Cr（Ⅵ）具有较强的选择吸附性.研究显示,PANI/PA吸附材料成功制备并具有稳定结构,能够对水中Cr（Ⅵ）实现有效去除,并具有较强的选择吸附性,因此对废水中Cr（Ⅵ）的去除具有潜在的应用价值.      

我国腾冲大气PAHs的可能来源分析

2005年10月22日至2006年10月21日,在云南腾冲一典型背景点进行了每周一次的大气采样,以监测季风期东南亚地区生物质燃烧导致的多环芳烃(PAHs)的输入状况.结果表明,监测期内总PAHs含量为43.1~156ng/m3 (平均值为87.9ng/m3).其中气相PAHs均值为85.8ng/m3,无明显的季节变化;颗粒相PAHs均值为2.35ng/m3,在春季出现显著高值,可能与东南亚生物质燃烧释放的PAHs在南亚季风作用下向腾冲的跨境迁移有关.颗粒相PAHs以毒害性较大的高环PAHs化合物为主,其在偏远地区生态系统中的累积可能带来一定的生态风险.     

原水碳源分子量分布及DPB效能对酸化时间的响应

采用超滤-纳滤膜法对污水中碳源分子量(MW)进行切割试验,并测定各区间总有机碳(TOC)浓度以了解污水碳源组成特性;同时采用污水酸化技术,研究在不同酸化时间,碳源分子量分布的变化及对厌氧-膜好氧-反硝化(A2N)工艺中反硝化聚磷菌(DPB)用碳和净污效能的影响.结果表明,试验原水TOC为(58.3±2.83) mg /L,其中颗粒有机碳(POC)为(38.05±1.65)mg /L,占65.27%,剩余溶解有机碳(DOC)在分子量0.5kDa以上区间呈现“W”型分布,其中 MW>100kDa、10k~5kDa、1k~0.5kDa、MW<0.5kDa区间碳源分别占36.20%、12.05%、13.68%和29.83%.在不同酸化时间下,POC含量与DOC分布存在显著差异,在12h内酸化,可以有效将POC转化为DOC,且在14mg/L左右趋于平衡;DOC在大于0.5kDa区间上的分布呈现随时间而整体后移的趋势,在8h时碳源质量最优,其中MW<1kDa的小分子有机物高达17.30mg/L;此时,DPB污泥在厌氧池与缺氧池中的碳源利用率分别为 83.48%、79.59%,比0h时分别提高了23.56%、18.03%;TN、TP去除率分别提高了14.63%、16.98%.     

地表夯击载荷作用下埋地管道力学分析

为研究地基强夯作业中夯击载荷对埋地管道力学性能的影响,基于有限元原理建立了夯锤-管道-围土耦合三维模型,分析了夯击过程中管道截面变形及所受冲击力变化规律,研究了管道壁厚、夯击速度、夯锤体积对管道应力、应变及变形的影响规律。结果表明:夯击载荷下的管道所受冲击力为脉冲型,且随时间推移逐渐降低为0,最大冲击力随管道壁厚、夯击速度、夯锤体积增大而增大;管道最大等效应力、高应力范围及最大等效塑性应变随壁厚增加而减小,但随夯击速度或夯锤体积增大而增大;随着夯击速度、夯锤体积增大,管道截面变形率（椭圆度或凹陷率）逐渐增大,但其随壁厚增加而减小。     

复合式渗流试验装置对微污染河道水的脱氮除磷研究

针对微污染河道水体的水质特点,考察了复合式渗流试验装置对此类河道水的处理效能。试验结果表明:在10 cm/d和20 cm/d水力负荷条件下,两个阶段TN的平均去除率分别为36.34%、28.53%;TN平均出水浓度分别为6.15,12.45 mg/L;TP的平均去除率分别为90.86%、64.15%;TP平均出水浓度分别为0.05,0.42 mg/L。氮的去除主要发生在前两个格室,前两个格室填充的腐木作为补充碳源,有利于微生物的反硝化脱氮作用;磷的去除主要发生在后两个格室,原因是后两个格室填充了水泥砖块,水泥砖块对磷具有较好的吸附性能,但随着时间的推移,系统的除磷能力会因填料对磷的吸附饱和而逐渐下降,故需要及时更换填料。     

厌氧折流内循环反应器(ABIC)处理木薯淀粉废水试验

对自主研发的厌氧折流内循环反应器(anaerobic baffled internal circulation,ABIC)处理木薯淀粉废水的运行特性进行研究,结果表明:ABIC在水力停留时间为20~24 h、进水ρ(COD)为3 000~15 000 mg/L、有机负荷为3.0~20.0kg/(m3·d)时COD去除率均高于80.0%,最高可达91.2%。ABIC对进水负荷的冲击具有良好耐受能力,最大可承受的容积负荷VLR为26.0 kg/(m3·d),运行稳定。反应器重新启动耗时较短,对处理木薯淀粉季节性生产废水有利。     

Effects of humic acid and surfactants on the aggregation kinetics of manganese dioxide colloids

The aggregation of common manganese dioxide (MnO₂) colloids has great impact on their surface reactivity and therefore on their fates as well as associated natural and synthetic contaminants in engineered (e.g. water treatment) and natural aquatic environments. Nevertheless, little is known about the aggregation kinetics of MnO₂ colloids and the effect of humic acid (HA) and surfactants on these. In this study, the early stage aggregation kinetics of MnO₂ nanoparticles in NaNO₃ and Ca(NO₃)₂ solutions in the presence of HA and surfactants (i.e., sodium dodecyl sulfate (SDS), and polyvinylpyrrolidone (PVP)) were modeled through time-resolved dynamic light scattering. In the presence of HA, MnO₂ colloids were significantly stabilized with a critical coagulation concentration (CCC) of ~300 mmol·L^-1 NaNO₃ and 4 mmol·L^-1 Ca(NO₃)₂. Electrophoretic mobility (EPM) measurements confirmed that steric hindrance may be primarily responsible for increasing colloidal stability in the presence of HA. Moreover, the molecular and/or chemical properties of HA might impact its stabilizing efficiency. In the case of PVP, only a slight increase of aggregation kinetics was observed, due to steric reactions originating from adsorbed layers of PVP on the MnO₂ surface. Consequently, higher CCC values were obtained in the presence of PVP. However, there was a negligible reduction in MnO₂ colloidal stability in the presence of 20 mg·L^-1SDS.     

沉管隧道对接端深基坑止水墙水下爆破对周围环境的影响研究

基于爆破动态效应的现场监测数据,研究了襄阳汉江鱼梁州沉管隧道对接端深基坑止水墙水下爆破对邻近建(构)筑物和周围水域的不利影响.结果 表明:爆源附近方圆50 rn范围内属于爆破振动近场区、方圆50～150 m范围内属于爆破振动过渡区、方圆150 m范围外属于爆破振动远场区;爆破振动近场区内薄壁支护结构爆破振动速度呈现高峰...     

Cathode ray tube (CRT) recycling: current capabilities in China and research progress

It is estimated that approximately 6,000,000 scrap TVs and 10,000,000 personal computers are generated each year in China. Cathode ray tubes (CRTs) from these machines consist of 85% glass (65% panel, 30% funnel and 5% neck glass). The leaded glass (funnel-24%, neck-30%) may seriously pollute the environment if it is not properly disposed of. In this paper, the past, current and future status of CRT dismantling technologies as well as the CRT glass recycling situation in China are presented and discussed. Recycling technology for waste CRTs in China is still immature. While the conventional CRT dismantling technologies have disadvantages from both economic and environmental viewpoints, some of the new and emerging treatments such as automatic optical sorting facilities that have been applied in developed countries offer advantages, and therefore should be transferred to China in the next few years to solve the CRT pre-processing problem. Meanwhile, because the demand for CRT glass closed-loop recycling is extremely limited, the authorities should take effective measures to improve CRT glass recycling rates and to facilitate a match to local conditions. Moreover, we also provide a broad review of the research developments in recycling techniques for CRT cullet. The challenge for the future is to transfer these environmentally friendly and energy-saving technologies into practice.     

铁炭微电解法降解1-丁基-3-甲基咪唑六氟磷酸盐

使用铁炭微电解法降解1-丁基-3-甲基咪唑六氟磷酸盐([BMIM]PF6),并探讨了铁炭微电解法降解[BMIM]PF6的影响因素、工艺条件及其反应动力学.结果表明,影响铁炭微电解降解[BMIM]PF6的因素按从大到小的顺序为:炭铁比、pH、反应时间;铁炭微电解降解[BMIM]PF6的最佳工艺条件是:铁粉用量3g.l-1、水样pH2.5、炭铁比2、反应时间为60—90min;在此条件下,[BMIM]PF6的去除效率可以达到90%以上且该降解反应为三级反应.