黄腐酸的萃取和性质研究

黄腐酸是腐植酸中最具活力的组成部分,蕴藏量丰富,萃取方法简便。研究了从红原1#泥炭中萃取黄腐酸和降解物。它的分子量较小,易溶于水,抗絮凝性能好,分子内含有较多的活性官能团,具有很高的化学活性和生物活性,用途广泛。     

Effects of Acid Rain on Competitive Releases of Cd, Cu, and Zn from Two Natural Soils and Two Contaminated Soils in Hunan, China

Leaching experiments of rebuilt soil columns with two simulated acid rain solutions (pH 4.6–3.8) were conducted for two natural soils and two artificial contaminated soils from Hunan, south-central China, to study effects of acid rain on competitive releases of soil Cd, Cu, and Zn. Distilled water was used in comparison. The results showed that the total releases were Zn>Cu>Cd for the natural soils and Cd>Zn≫Cu for the contaminated soils, which reflected sensitivity of these metals to acid rain. Leached with different acid rain, about 26–76% of external Cd and 11–68% external Zn were released, but more than 99% of external Cu was adsorbed by the soils, and therefore Cu had a different sorption and desorption pattern from Cd and Zn. Metal releases were obviously correlated with releases of TOC in the leachates, which could be described as an exponential equation. Compared with the natural soils, acid rain not only led to changes in total metal contents, but also in metal fraction distributions in the contaminated soils. More acidified soils had a lower sorption capacity to metals, mostly related to soil properties such as pH, organic matter, soil particles, adsorbed SO₄ ²⁻, exchangeable Al³⁺ and H⁺, and contents of Fe₂O₃ and Al₂O₃.     

盐效萃取法从电子产品清洗废液中回收异丙醇

用盐效萃取法从电子产品清洗废液中回收片丙醇，考察了碳酸钾水溶液与该清洗废液的质量比对脱水率的影响，测定了异丙醇-水-碳酸钾体系存40℃时的液液相平衡数据，用Pitzer理论和NRTL方程对液液相平衡数据进行了理论计算。结果表明：当质量分数为60．00％的碳酸钾水溶液与该废液的质晕比为2．00时，脱水率高达90．00％；将有机相进行精馏可得到质量分数为99．50％的异丙醇；计算值与实测值接近，水相和有机相的绝对平均偏差分别为0．62％和0．46％。     

用烧结法从沸腾炉渣中提取铝和铁的研究

把沸腾炉渣和石灰及精煤混合制成小球,然后在大约1 000 ℃下烧结.取不同烧结时间的样品用硫酸浸取,得到含有铝离子和铁离子的溶液.试验表明,采用浓度为4 mol/l的硫酸,在80 ℃下浸取烧结球样品(50%沸腾炉渣∶40%精煤∶10%石灰)24 h,可以得到铝和铁的最大提取率,分别为86.50%和94.60%.滤渣可以作为固化材料用于高速公路的路基建设或水泥生产中的添加剂.     

响应面法优化养殖水体中炔雌醇的固相萃取条件

在单因素试验、Plackett-Burman设计试验基础上,采用Box-Behnken响应面法对养殖水体中炔雌醇(EE2)的固相萃取条件进行优化。结果表明,洗脱液体积、洗脱液组成和淋洗液体积是影响EE2固相萃取回收率的3个主要因素;EE2的最佳固相萃取条件为:水样pH值为3,进样流量为3.0 mL/min,淋洗液为体积分数为10%的甲醇水溶液,淋洗液体积7.0 mL,洗脱液为乙酸乙酯-正己烷混合溶液(体积比为9∶1),洗脱液体积12.0 mL。该条件下养殖水样中EE2固相萃取回收率为81.6%～86.7%。     

Direct supercritical fluid extraction from water

Abstract

This paper describes the development of apparatus suitable for direct supercritical fluid extraction of organics from water. Results are presented for the extraction of pentachlorophenol present in water at concentrations of the order of 0.1 ppm. The effect of changes in apparatus design and supercritical fluid flow rate on recovery are discussed.     

乳状液膜法处理煤制兰炭废水

以磷酸三丁酯(TBP)为载体、煤油为膜溶剂、NaOH水溶液为内水相，采用乳状液膜法处理兰炭废水。实验结果表明:当TBP体积分数为4%、表面活性剂质量分数为4%、内水相NaOH质量分数为12%、油内比(乳状液的油相与内水相的体积比)为3∶2、乳水比为1∶5、萃取时间为15min时，废水中的酚类(以苯酚计)去除率达到85%以上，COD去除率达83%以上。     

Effect of biosolid incorporation to mollisol soils on Cr, Cu, Ni, Pb, and Zn fractionation, and relationship with their bioavailability

Biosolid application to soil may be a supply of nutrients and micronutrients but it may also accumulate toxic compounds which would be absorbed by crops and through them be incorporated to the trophic chain.

The present study deals with the effect of biosolid application on Cr, Cu, Pb, Ni, and Zn in agricultural soils. The procedure used is sequential extraction so that the availability of those metals may be estimated and related to their bioavailability as determined through two indicator plants grown in greenhouse: ryegrass (Lolium perenne L.) and red clover (Trifolium pratense). Results showed that biosolid application to soil increased total Cu and Zn content. Sequential extraction showed that the more labile Zn fractions increased after biosolid application to soil. This was confirmed when assessing the total content of this metal in shoot and root of the plants under study, since a higher content was found in plant tissues, while no significant differences were found for Cu, Cr, Ni, and Pb.     

从顽拗植物荔枝中提取基因组DNA技术的研究

针对荔枝体内含有大量影响ＤＮＡ提取质量的多酚等次生代谢物质的特点，在常规ＳＤＳ和ＣＴＡＢ提取方法的基础上做了技术改进，即在核裂解之间先破碎细胞，将存在于细胞质中次生物质除去后再裂解细胞核，同时加入活性炭以吸咐杂质反复清洗几次后加入核型解液释放基因组ＤＮＡ，纯化之后经外观和电泳检测，以及Ｄ２６０ｎｍ和Ｄ２８０ｎｍ比值的测定，限制性内切酶反应，ＰＣＲ扩增的结果表明，用改进方法提取的ＤＮＡ无论在纯度上还     

底泥中多环芳烃(PAHs)提取方法评析

总结了底泥中多环芳烃(PAHs)提取的处理流程和国内外多种提取方法,比较了几种在我国较为常用的提取方法的效率.同时还提出了PAHs分离纯化的方法和步骤,并指出了提取过程中影响实验回收率的几个因素.