Cu~(2+)助芬顿法处理高浓度邻苯二甲酸二甲酯废水

Cu2+可以与H2O2发生类Fenton反应,用Fenton法处理同时含有难降解有机物和Cu2+的工业废水时,Cu2+对于Fenton氧化难降解有机物的反应具有促进作用。本实验在高浓度邻苯二甲酸二甲酯(DMP)和Cu2+组成的模拟工业废水中投加Fenton试剂(Fe2++H2O2),利用Cu2+辅助Fe2+催化Fenton反应氧化难降解有机物。通过正交实验,优选反应条件,并进行单因素实验,分析不同Cu2+浓度、初始H2O2浓度、H2O2∶Fe2+(摩尔比)、pH及温度对DMP去除率的影响,以确定最佳的反应条件,并对反应机理进行了初步探讨。当Cu2+浓度为10 mg/L、DMP浓度为250 mg/L、初始H2O2的浓度为499.5 mg/L、H2O2∶Fe2+的摩尔比为4∶1、温度为20℃时,DMP的去除率最高可达到98.67%。本研究为类芬顿法处理难降解有机物和重金属离子共存的复杂工业废水奠定了基础。     

城市生活垃圾中纤维素含量测定方法优化

对传统硫酸法进行改进,建立适用于城市生活垃圾纤维素含量的测定方法。以脂肪抽提时间、硫酸浓度、水解反应温度、水解反应时间、稀释硫酸浓度、回流时间为考察因素进行6因素5水平正交实验。结果表明,测定纤维素含量的最佳条件为：脂肪抽提时间4h、硫酸浓度70％、水解反应温度30℃、水解反应时间5h、稀释硫酸浓度5％、回流时间3h。优化后纤维素测定条件RSD均小于1．69％,平均回收率98．76％,表明该方法的精度高,可靠行强。     

论公共文化环境建设的资源管理机制

通过对相关文献资料的梳理和分析,以安徽省财政支持公共文化服务体系建设为例,运用定量和定性研究相结合的方法,在充分的问卷调查及实地调研的基础上,总结了我国公共文化建设资源投入机制的实践与制度经验,指出了公共文化建设在资源投入及管理方面所存在的主要问题:财政投入的实际效益低下、资源保障机制不科学、公共文化服务软件投入不足、公共文化服务资源管理体制的结构性矛盾等.有鉴于此,文章分别从宏观与微观层面探讨了如何构建公共文化服务良性运行的资源管理机制,基于宏观政策与制度设计层面提出:创新公共文化建设资源管理的政策支持方式,建立基层公共文化服务的长效机制,构筑公共文化环境建设的资源分级保障机制,完善公共文化建设的人才环境,创设公共文化环境建设的资源整合机制,实施公共文化服务的运行评估与绩效评价机制.基于微观对策与措施层面提出:科学地确定现阶段公共文化建设的资源保障重点并明确各级财政的投入范围和基本保障的支出责任,转变公共文化财政资金的投入方式,改变公共文化环境建设的资源投入结构,完善公共文化建设的资金管理方式,等等.     

Qualitative analysis of volatile organic compounds on biochar

Qualitative identification of sorbed volatile organic compounds (VOCs) on biochar was conducted by headspace thermal desorption coupled to capillary gas chromatographic-mass spectrometry. VOCs may have a mechanistic role influencing plant and microbial responses to biochar amendments, since VOCs can directly inhibit/stimulate microbial and plant processes. Over 70 biochars encompassing a variety of parent feedstocks and manufacturing processes were evaluated and were observed to possess diverse sorbed VOC composition. There were over 140 individual chemical compounds thermally desorbed from some biochars, with hydrothermal carbonization (HTC) and fast pyrolysis biochars typically possessing the greatest number of sorbed volatiles. In contrast, gasification, thermal or chemical processed biochars, soil kiln mound, and open pit biochars possessed low to non-detectable levels of VOCs. Slow pyrolysis biochars were highly variable in terms of their sorbed VOC content. There were no clear feedstock dependencies to the sorbed VOC composition, suggesting a stronger linkage with biochar production conditions coupled to post-production handling and processing. Lower pyrolytic temperatures (?350 °C) produced biochars with sorbed VOCs consisting of short carbon chain aldehydes, furans and ketones; elevated temperature biochars (>350 °C) typically were dominated by sorbed aromatic compounds and longer carbon chain hydrocarbons. The presence of oxygen during pyrolysis also reduced sorbed VOCs. These compositional results suggest that sorbed VOCs are highly variable and that their chemical dissimilarity could play a role in the wide variety of plant and soil microbial responses to biochar soil amendment noted in the literature. This variability in VOC composition may argue for VOC characterization before land application to predict possible agroecosystem effects.     

用铝灰生产聚合氯化铝的工艺研究

以铝灰、废盐酸为原料,用酸溶法(一步法)生产液体聚合氯化铝,对投料比、反应温度、反应时间、搅拌速度、熟化温度、熟化时间等参数对产品性能的影响进行了试验,得到了最佳生产工艺条件,并对产品的净水效果进行了模拟试验,净水效果明显。     

Sentiment analysis of the Twitter response to Netflix's Our Planet documentary

The role of nature documentaries in shaping public attitudes and behavior toward conservation and wildlife issues is unclear. We analyzed the emotional content of over 2 million tweets related to Our Planet, a major nature documentary released on Netflix, with dictionary and rule-based automatic sentiment analysis. We also compared the sentiment associated with species mentioned in Our Planet and a set of control species with similar features but not mentioned in the documentary. Tweets were largely negative in sentiment at the time of release of the series. This effect was primarily linked to the highly skewed distributions of retweets and, in particular, to a single negatively valenced and massively retweeted tweet (>150,000 retweets). Species mentioned in Our Planet were associated with more negative sentiment than the control species, and this effect coincided with a short period following the airing of the series. Our results are consistent with a general negativity bias in cultural transmission and document the difficulty of evoking positive sentiment, on social media and elsewhere, in response to environmental problems.     

Chemical composition and quantitative relationship between meteorological condition and fine particles in Beijing

The recent year‘s monitor results of Beijing indicated that the pollution level of fine particles PM2.5 showed an increasing trend. To understand pollution characteristics of PM2.5 and its relationship with the meteorological conditions in Beijing, a one-year monitoring of PM2.5 mass concentration and correspondent meteorological parameters was performed in Beijing in 2001. The PM2.5 levels in Beijing were very high, the annual average PM2.5 concentration in 2001 was 7 times of the National Ambient Air Quality Standards proposed by US EPA. The major chemical compositions were organics, sulfate, crustals and nitrate. It was found that the mass concentrations of PM2.5 were influenced by meteorological conditions. The correlation between the mass concentrations of PM2.5 and the relative humidity was found. And the correlation became closer at higher relative humidity. And the mass concentrations of PM2.5 were negtive-correlated to wind speeds, but the correlation between the mass concentration of PM2.5 and wind speed was not good at stronger wind.     

2005年夏季环渤海16条主要入海河流的污染状况

2005-07-01～2005-07-05对环渤海的黄河等16条主要河流的入海污染同步调查显示,13条河流断面的水质属于Ⅳ类以上,其中子牙新河等8条河流水质属于劣Ⅴ类,通过污染分担率分析,环渤海河流的首要污染物为石油类（11条河流）,其次为营养盐,高锰酸盐指数仅位居第3.采用综合营养状态指数法评价,大辽河、黄河等7条河流处于富营养状态,而小清河、蓟运河等7条河流处于重度富营养状态,可见环渤海河流的富营养化现象非常严重.有机污染物的调查显示,16条河流断面采样点TOC的平均值为16 .41 mg/L,高锰酸盐指数的平均值为6 .04 mg/L,其中易降解有机物所占比例平均为15 .61%,表明虽然环渤海16条河流中的化学需氧有机物质的污染严重,但总有机物的入海通量更大,这一点必须引起足够的重视.     

对环境空气质量预测中不利气象条件的研究

评价区域内的气象条件是影响大气环境影响预测结果的重要因子.为寻找可能的最大影响,须设置可能发生的不利于污染物传输与扩散的气象条件.分别以城市和郊区的高、中和低架源为例,计算其在各种风速和稳定度组合情况下的最大地面浓度,利用Screen3模式,寻找各类污染源对环境影响最大时的不利气象条件,以及需关注的环境空气敏感点(区).结果表明:小风速和强不稳定度是城市和郊区2类源的不利气象条件;而城市源的不利气象条件还可能出现在小风速和稳定类的情况下. 由于城市高架源影响范围广,评价时更应关注整个评价区域的环境空气敏感点;虽然城市高架源的影响程度比郊区高架源小,但城市低架源的影响程度却大于郊区低架源.      

pH对过一硫酸氢盐湿法氧化去除甲硫醇恶臭气体的影响

以过一硫酸氢盐(PMS)作为氧化剂,利用化学吸收氧化法去除甲硫醇(CH3SH)恶臭气体.研究了p H(2~13)对CH3SH吸收过程、PMS氧化降解CH3SH过程的影响.结果表明,PMS不同于H2O2,在p H小于CH3SH p Ka(10.3)的弱碱性条件(p H=8~10)下,也可以有效去除CH3SH,而此时H2O2对CH3SH没有去除效果.可能的原因是,在弱碱性条件(p H=8~10)下PMS或可能产生的活性物种在气液相界面直接快速氧化CH3SH分子.