树脂及活性碳吸附技术回收大豆乳清中的异黄酮和低聚糖

对用树脂及活性碳吸附方法回收大豆乳清废水中的大豆异黄酮和低聚糖进行了研究。测定了树脂及活性碳吸附饱和曲线，研究了异黄酮和低聚糖的洗脱条件，建立了该法处理大豆乳清废水回收大豆异黄酮和精制大豆低聚糖的工艺。结果表明：处理1t废水，约可回收40%的大豆异黄酮130g，精制大豆低聚糖浆9kg，并将乳清废水的COD和BOD分别由13600和7800降至960和340。本法处理乳清废水可创造良好的经济效益。     

沙粒中添加Ca2+、粘土以及富粘土对水溶性有机碳呼吸作用及其吸附的影响研究

Clay addition to light-textured soils is used to ameliorate water repellency and to increase nutrient retention. However, clay addition may also increase the potential to bind organic matter and thus C sequestration. Divalent calcium ions （Ca2＋） play an important role in binding of organic matter to clay because they provide the bridge between the clay particles and organic matter which are both negatively charged. In the first experiment, quartz sand was mixed with clay isolated from a Vertosol at rates of 0, 50 and 300 g kg-1, finely ground mature wheat residues （20 g kg-1） and powdered CaSO4 at 0, 5 and 10 g kg-1. Soil respiration was measured over 28 d. Compared to the sand alone, addition of isolated clay at 300 g kg-1 increased cumulative respiration with a stronger increase than that at 50 g kg-1. Addition of CaSO4 increased electrical conductivity, decreased sodium adsorption ratio and reduced cumulative respiration. The latter can be explained by enhanced sorption of organic matter to clay via Ca2＋ bridges. In a second experiment, isolated clay or subsoil of the Vertosol without or with powdered CaSO4 at 10 g kg-1 were used for a batch sorption with water-extractable organic C （WEOC） from wheat straw followed by desorption with water. Addition of 10 g kg-1 CaSO4 increased sorption and decreased desorption of WEOC in both subsoil and isolated clay. In the third experiment, subsoil of the Vertosol was used for a batch sorption in which WEOC was added repeatedly. Repeated addition of WEOC increased the concentration of sorbed C but decreased the sorbed proportion of the added WEOC. This indicates that sorption of WEOC may be underestimated if it is added only once in batch sorption experaments.     

Phosphorus accumulation and leaching risk of greenhouse vegetable soils in Southeast China

Over-fertilization has caused significant phosphorus(P) accumulation in Chinese greenhouse vegetable production(GVP) soils. This study, for the first time, quantified profile P accumulation directly from soil P measurements, as well as subsoil P immobilization, in three alkaline coarse-textured GVP soil profiles with 5(S5), 15(S15), and 30(S30) years of cultivation in Tongshan, Southeast China. For each profile, soil samples were collected at depths of 0–10(topsoil), 10–20, 20–40, 40–60, 60–80, and 80–100 cm. Phosphorus accumulation was estimated from the difference in P contents between topsoil and parent material(60–100 cm subsoil). Phosphorus mobility was assessed from measurements of water-soluble P concentration(PSol). Finally, P sorption isotherms were produced using a batch sorption experiment and fitted using a modified Langmuir model. High total P contents of 1 980(S5), 3 190(S15), and 2 330(S30) mg kg~(-1) were measured in the topsoils versus lower total P content of approximately 600 mg kg~(-1) in the 80–100 cm subsoils. Likewise, topsoil PSol values were very high, varying from 6.4 to 17.0 mg L~(-1). The estimated annual P accumulations in the topsoils were 397(S5), 212(S15), and 78(S30) kg ha~(-1) year~(-1). Sorption isotherms demonstrated the dominance of P desorption in highly P-saturated topsoils, whereas the amount of adsorbed P increased in the 80–100 cm subsoils with slightly larger P adsorption capacity. The total P adsorption capacity of the 80–100 cm subsoils at a solution P concentration of0.5 mg L~(-1) was 15.7(S5), 8.7(S15), and 6.5(S30) kg ha~(-1), demonstrating that subsoils were unable to secure P concentrations in leaching water below 0.5 mg L~(-1) because of their insufficient P-binding capacity.     

表面解吸常压化学电离质谱结合人工神经网络鉴别新陈莲子

为实现对新陈莲子的快速鉴别,该文采用自行研制的表面解吸常压化学电离质谱（DAPCI-MS）,在无需样品预处理的前提下,直接对新鲜和陈年莲子切面进行质谱检测,获得其化学指纹图谱,并通过主成分分析（PCA）和反向传输人工神经网络技术（BP-ANN）对所获指纹谱图信息进行分析,获得新鲜和陈年莲子的质谱信息特征。结果表明,在负离子模式下,DAPCI-MS结合化学计量学方法,实现了新鲜和陈年莲子的快速鉴别,其测试样本准确率分别为95.0%和91.7%;对不同年份莲子也能够有效地分类判别,2012、2011、2010和2009年莲子测试样本准确率分别为90%,85%,85%和90%。该方法具有分析速度快,信息提取准确,识别精度高等优点,为其他粮食谷物品质的鉴定提供参考。     

Adsorption,desorption and dissipation of metolachlor in surface and subsurface soils

BACKGROUND: Variations in soil properties with depth influence retention and degradation of pesticides. Understanding how soil properties within a profile affect pesticide retention and degradation will result in more accurate prediction by simulation models of pesticide fate and potential groundwater contamination. Metolachlor is more persistent than other acetanilide herbicides in the soil environment and has the potential to leach into groundwater. Reasonably, information is needed about the dissipation and eventual fate of metolachlor in subsoils. The objectives were to evaluate the adsorption and desorption characteristics and to determine the dissipation rates of metolachlor in both surface and subsurface soil samples. RESULTS: Adsorption of metolachlor was greater in the high‐organic‐matter surface soil than in subsoils. Lower adsorption distribution coefficient (K_ads) values with increasing depth indicated less adsorption at lower depths and greater leaching potential of metolachlor after passage through the surface horizon. Desorption of metolachlor showed hysteresis, indicated by the higher adsorption slope (1/n_ads) compared with the desorption slope (1/n_des). Soils that adsorbed more metolachlor also desorbed less metolachlor. Metolachlor dissipation rates generally decreased with increasing soil depth. The first‐order dissipation rate was highest at the 0–50 cm depth (0.140 week^?1) and lowest at the 350–425 cm depth (0.005 week^?1). Degradation of the herbicide was significantly correlated with microbial activity in soils. CONCLUSION: Metolachlor that has escaped degradation or binding to organic matter at the soil surface might leach into the subsurface soil where it will dissipate slowly and be subject to transport to groundwater. Copyright © 2009 Society of Chemical Industry     

不同添加剂对土壤中乙草胺吸附/解吸的影响

采用批处理恒温振荡法,利用气相色谱-质谱联用仪研究了人工添加不同吸附物质对土壤中乙草胺的吸附/解吸作用.结果表明,人工添加不同吸附物质对土壤中乙草胺的吸附强度和吸附容量不同,不同的添加剂对土壤中乙草胺的吸附懈吸作用均呈现明显的非线性关系,可用Freundlich模型描述.并且随着土壤中添加剂量的增大,吸附强度增大、吸附容量增大、所得吸附等温线的非线性也逐步增大;另外,添加剂对乙草胺的解吸迟滞作用也随添加剂含量的增高而更加明显.但是不同添加剂对土壤中乙草胺的吸附能力有明显差异,其中煤粉的吸附能力最大,其次是壳聚糖,沸石最小.     

枸杞吸附与解吸等温线修正GAB模型计算模拟

本文阐述了枸杞吸附与解吸等温线修正CAB模型计算和模拟算法的原理及算法流程,实现了枸杞吸附与解吸等温线修正GAB模型的模拟分析,为分析与模拟其他农产品吸附与解吸等温线提供参考.     

不同磷含量对石灰性潮土吸附、解吸有效性锌的影响

以不同磷含量的石灰性潮土为材料,通过对锌的吸附、解吸试验,研究了磷对石灰性土壤中锌有效性的影响,结果表明,随着石灰性土壤中磷含量的提高,土壤对锌的吸附量和吸附能力显著降低,而KCl对锌的解吸量却明显增加,从而得出石灰性土壤中施磷促进了土壤中锌的有效性是施磷促进作物对锌吸收的一个原因.     

我国某些土壤中硫素的氧化

The status and activities of boron in soils were studied by the approach of electro-ultrafiltration(EUF).The samples of soils,including brown-red soil and calcareous alluvial soil,were collected from Hubei Province of China.The soil samples were incubated in saturated water and then their nutrients were ultrafiltrated with EUF equipment.Filtration and extraction were conducted in accordance with routine process,but fractions in anode and cathode were all collected.Analyses of B,K^ ,Mg^2 ,Ca^2 ,Cl^- and pH in fractions supposed that boron existed not only in a simple form of borate but also in ion -pair with cations partly in acidic soil,and borate was the primary form existing in the calcareous soil.In studying desorption kinetics with EUF,the boron content of Fractions 2-6 was accumulated.and the accumlative quantities were fit to time factors in three kinetic equations:the zero-order,first-order,and parabolic diffusion equations,Fit degree of the parabolic diffusion equation was the best,followed by the zero-order equation,and the first-order equation was the worst。