Fenton法降解垃圾渗滤液中的溶解性有机质

垃圾渗滤液是一种高浓度难降解废水,含有大量有毒物质和溶解性有机质（dissolved organic matter, DOM）,可生化性差。Fenton试剂（Fe2++H2O2）能产生活性极强的羟基自由基（·OH）,能快速氧化渗滤液中DOM和微量有机物质。本研究采用Fenton法处理垃圾渗滤液,结果表明,在优化的处理条件下,渗滤液COD和TOC去除率分别为65%和42%,其中混凝作用去除的COD和TOC分别为20%和21%。进一步通过紫外可见光谱扫描、SUVA254、E3/E4等指标评价,发现Fenton法可以有效降低渗滤液中的DOM含量,大分子有机物的含量明显减少,而分子量小的有机物含量相对增加,反应体系中溶解性有机物分子量随着反应的进行而降低,腐殖化程度降低。利用GC-MS定性出渗滤液原液中47种有机物,该类有机物在Fenton反应后上清液中未再检出,但5种物质（邻苯二甲酸二（2-乙基己）酯、植酮、角鲨烯、麥角甾烷醇和二氢胆固醇）在沉淀的铁泥中检出。研究发现不同pH值、H2O2和Fe2+浓度条件下,残留的COD与DOM、TOC和UV254存在显著的相关关系（R2> 0.9）。本研究结果为改进垃圾渗滤液处理工艺和探索DOM在Fenton过程中的降解行为提供科学依据。     

生物质型煤成型技术开发实验研究

通过原有成型方式的工业成型观察和模压成型实验，提出并验证了完全利用生物质纤维的交联作用实现成型的新机制。其于中高压下物料的不可再压缩性和单向挤压也会导致更高的成型压力的新认识，设计和研制成按新机制成型的型轮。经此改进的工业成型试验达到了比模压成型更好的效果：不用预实送料，且成型性能；成型压力降至120MPa以下，成型许可水分成倍提高，适合的生物质配比范围15％－60％；仅利用送料螺旋的预实功能，即可实现纯生物质型块的成型。     

The organic precursors affecting the formation of disinfection by-products with chlorine dioxide

The object of this research was to study the formation of disinfection by-products by using chlorine dioxide (ClO2) as a disinfectant reacting with different properties of organic substance in natural aquatic environment. The adsorbent resin (XAD-4, XAD-7) was used to divide the organic matters in raw water into three groups. The influence of the function groups on structure, reaction tendency, and formation of disinfection by-products generated by the reaction of these organic substances with chlorine dioxide was explored. The experimental results show that the three different organic groups formed using adsorbent resin were hydrophobic substance, hydrophilic acid, and non-acid hydrophilics in proportions of 43%, 41%, and 16%, respectively. Within the raw water in our study, the hydrophilic substance had a higher distribution proportion than that described in general articles and journals, which indicates that this water was contaminated with pollution from human beings. The exploration of the reactivity of the three different organic substances with chlorine dioxide shows that the unit consumption of disinfection agent per unit organic matters (represented by ClO2/DOC) is in the following sequence hydrophobic substance > hydrophilic substance > non-acid hydrophilics. It indicated that larger molecular organic precursors had larger consumption of disinfectant. We also discovered that after the reaction of the three different organic substances with chlorine dioxide, the largest amount of disinfection by-products were generated by the non-acid hydrophilics.     

Characteristics of organic precursors and their relationship with disinfection by-products

The molecular weight distribution and chemical composition of precursors and their relationship with disinfection by-products (DBPs) were investigated. Most of the organic matter responsible for the major DBP precursors in the Pan-Hsin water are small compounds with a molecular weight less than 1 kDa. The hydrophobic acids display the greatest ability to produce DBP. Therefore, effective removal of small molecules or hydrophobic acidic organics prior to disinfection process will significantly reduce the DBP concentration in the finished water. Although the coagulation process is effective in removing large organic precursors and the removal efficiencies of CHCl3 formation potential and organic carbon increase proportionally to the molecular weight of the precursors, the conventional treatment methods have limited efficiency in eliminating small precursors, which have high DBP formation potential.     

Interactive analysis of waste recycling and energy recovery program in a small-scale incinerator

Conflicting goals affecting solid waste management are explored in this paper to find the best implementation of resource recovery with a small-scale waste-to-energy process. Recycling paper and plastic material often leaves a shortage of thermal energy to support incineration that forces operators to supplement the process with auxiliary fuels. Although there are considerable profits to be made from material recovery, the increase of fuel usage causes conflict given that it is cost prohibitive. A series of trials performed on a small-scale 1.5-t/day incineration plant with a cyclone heat recovery system found that material recycling can impede performance. Experimental results are expressed as empirical regression formulas with regard to combustion temperature, energy transfer, and heat recovery. Process optimization is possible if the waste moisture content remains <30%. To test the robustness of the optimization analysis, a series of sensitivity analyses clarify the extent of material recycling needed with regard to plastic, paper, and metal. The experiments also test whether the moisture in the waste would decrease when recycling paper because of its exceptional capacity to absorb moisture. Results show that recycling paper is strongly recommended when the moisture content is >20%, whereas plastic recycling is not necessary at that moisture condition. Notably, plastic recovery reduces the heat needed to vaporize the water content of the solid waste, thus it is recommended only when the moisture content is <10%. For above-normal incineration temperatures, plastic recycling is encouraged, because it removes excess energy. Metal is confirmed as an overall priority in material recycling regardless of the moisture content of the incoming waste.     

Anaerobic degradation of diethyl phthalate, di-n-butyl phthalate, and di-(2-ethylhexyl) phthalate from river sediment in Taiwan

We investigated anaerobic degradation rates for three phthalate esters (PAEs), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), and di-(2-ethylhexyl) phthalate (DEHP), from river sediment in Taiwan. The respective anaerobic degradation rate constants for DEP, DBP, and DEHP were observed as 0.045, 0.074, and 0.027 1/day, with respective half-lives of 15.4, 9.4, and 25.7 days under optimal conditions of 30 °C and pH 7.0. Anaerobic degradation rates were enhanced by the addition of the surfactants brij 35 and triton N101 at a concentration of 1 critical micelle concentration (CMC), and by the addition of yeast extract. Degradation rates were inhibited by the addition of acetate, pyruvate, lactate, FeCl₃, MnO₂, NaCl, heavy metals, and nonylphenol. Our results indicate that methanogen, sulfate-reducing bacteria, and eubacteria are involved in the degradation of PAEs.     

Local circulation and aerosol water-soluble ions--a case study in Taiwan during Mei-yu season

The Mei-yu (plum rain) season is a short but important period when the weather changes from spring to summer in Taiwan. In this study, size-segregated aerosols were collected alternately at 5 sampling sites in northwestern Taiwan from June 16 to 24, 1994. For the first time in Taiwan, this study revealed the aerosol mass spectra and water-soluble ions in the Mei-yu season. For all samples, a bi-modal aerosol mass spectra was found with modal diameters at 3.2 and 0.32 microm, respectively. The aerosol samples were able to be divided into different groups to show their mass and ion spectra according to the calculated 5-hr backward air trajectory. The utilization of enrichment factors showed that aerosol Cl-, Na+, and Mg2+ for all sizes, and super-micron SO4(2-) were related to the sea. Both the scheme of "chlorine loss" (Ohta and Okita, 1990) and a multivariate analysis (Thurston and Spengler, 1985) for categorizing water-soluble ions showed that sea-salts were major contributors in the prevalence of a sea breeze. In contrast, the secondary salts were significant for land breeze and a mix of land-sea breeze. In conclusion, the influence of local circulation on the distribution of aerosol mass and ionic species was found to be prominent.     

Effect of adsorbents coated with titanium dioxide on the photocatalytic degradation of propoxur

Photocatalytic oxidation of pesticides in aqueous media irradiated by UV light is a rapidly growing field of research. Therefore, the treatment technology for degradation of propoxur (an insecticide) using titanium dioxide coated on the supports such as activated carbon, zeolite, brick, quartz and glass beads, was performed in this research. Results show that GAC/TiO2 is the best complexing agent for oxidizing propoxur because of its adsorption properities. The others follow the sequence: plain TiO2 > glass beads > zeolite > brick > quartz. The degradation rate of propoxur with plain TiO2 is higher than that with TiO2/GAC complexing agent. But the mineralization rate of propoxur with plain TiO2 is lower than that with TiO2/GAC complexing agent. However, it can be concluded that using GAC as the support can improve the photocatalytic efficiency.     

三峡二期工程与湖北的机遇和挑战

１９９７年１１月１８日,三峡工程大江截流成功,标志着第一期工程结束、进入第二期工程实施阶段。长江三峡水利枢纽具有防洪、发电、航运和供水等巨大综合效益,是跨世纪特大型水利工程。它的建设,不仅对我国能源秘至整个经济布局产生极大的影响,而且对湖北长江经济带的形成与发展具有决定性的意义。     

TRMM和GPM卫星降水数据在中国三大流域的降尺度对比研究

以中国三大流域为研究区域,分别针对TRMM 3B43和GPM IMERG降水数据,构建基于归一化植被指数(NDVI)和数字高程模型(DEM)数据的地理加权回归(GWR)模型,以2014年夏季(6～8月)数据为例,得到了三大流域1 km分辨率的降尺度降水数据,并进一步通过气象站点数据对降尺度结果进行验证.研究表明:(1) GPM原始数据整体精度优于TRMM数据,两种数据在黄河流域的精度评价指标优于长江流域与珠江流域;(2)经降尺度计算,两种数据空间分辨率得到了显著提高,且表现出更多降水变化的细节与趋势,但精度指标对原始数据依赖性大,导致提升并不显著;(3)当联合使用NDVI及DEM作为GWR降尺度模型的辅助变量时,两种降尺度结果的差异值在长江流域与珠江流域的高海拔地区中更为显著;(4)黄河流域中,使用不同辅助变量下的降尺度结果在空间分布上总体相似.TRMM数据使用地形作为单独辅助变量的降尺度结果最佳,而GPM数据不同辅助变量下降尺度结果差异并不明显.