Functionalized Dipicolinic Acid Derivatives as TALSPEAK-MME Stripping Agents

ABSTRACT

This work describes the results of an assessment of two derivatives of dipicolinic acid (DPA) as the actinide-selective stripping reagents in the combined HEH[EHP]/Cyanex-923 system, TALSPEAK-MME (mixed monofunctional extractants). One purpose of this investigation is to demonstrate probable advantages derived in phase-transfer kinetics by deploying dipicolinates as preorganized aminopolycarboxylate complexants in TALSPEAK-derived separation systems. The investigation is focused on the behavior of the lanthanides, Am, and selected transition metals (Zr, Mo, Pd, Ru, and Rh) in the extraction, solvent conditioning, and stripping steps. Solvent conditioning with glycine buffer solutions is shown to be effective for the removal of entrained HNO₃ while also managing Pd concentration prior to actinide stripping. The efficacy of the DPA derivative during the actinide-selective strip was assessed, focusing explicitly on the effects of pH and ligand concentration and evaluating the stripping kinetics. These ligands were shown to be highly selective for americium, producing in the TALSPEAK-MME platform separation factors comparable to commonly used actinide selective stripping agents for radiotracer Eu, Am, a trans-lanthanide series and selected transition metals. The stripping kinetics study revealed very rapid phase-transfer reactions, reaching equilibrium in less than 10 s on vigorous agitation. Further work will be required to address the possible contamination of the product by selected transition metals (such as Zr) during the stripping step.     

The alginate fermentation strain Pantoea sp. F16-PCAi-T3P21 and ethanol production

Bio-ethanol production from algae is a promising way to help solve the energy problem. Alginate is a major component of algae, but it cannot be utilized by existing ethanol fermentation microorganisms. In order to improve the utilization rate of brown algae, high alginate fermentation strains should be obtained. In this research, strains for algae fermentation were got from several experiments. The ethanol yield of strain A was the highest, which was 0.095 g/g (ethanol to alginate). The identification of strain A was carried out and it was 99% identical to Pantoea sp. F16-PCAi-T3P21. Fermentation experiments with different substrates were carried out, such as laminaran, mannitol, L. japonica and acid hydrolysate of L. japonica, and the ethanol yield rate of L. japonica acid hydrolysate was the highest, which reached 0.17 g/g ethanol to L. japonica. It showed that strain A can converse alginate to ethanol in a relatively high yield rate, and might be a promising strain with L. japonica as the substrate, we believe more research should be carried out on this strain.     

Intrinsic affinity of acid-activated bentonite towards hydrogen and carbon dioxide

The effect of acid activation on bentonite affinity toward carbon dioxide (CO₂) and hydrogen (H₂) was investigated at ambient conditions. Characterization through X-ray diffraction and fluorescence, thermal gravimetric analysis, nitrogen adsorption-desorption isotherms, Fourier Transform Infrared spectroscopy and differential scanning calorimetry allowed correlating newly induced textural and structural features with adsorptive properties. Optimum acid treatment improved the specific surface area and porosity. The resulting decrease in dehydration temperature indicates decay in hydrophilic character. The affinity improvement towards hydrogen was due to Brønsted acidity suppression and surface basicity attenuation, which are essential requirements for adsorption on aluminosilicates (AS) via weak Lewis Acid-Base interactions, but excessive acid attack was detrimental. Low Si/Al surfaces should be suitable for CO₂ capture, while moderately acid-treated clays should be interesting candidates as hydrogen adsorbents. This allows envisaging promising prospects for low-cost AS-based materials intended for selective CO₂-free capture and storage of hydrogen without energy and safety constraints.     

Effect of different fibres on texture,rheological and sensory properties of acid casein processed cheese sauces

The objective of this study was the evaluation of different fibres (bamboo, acacia, potato or citrus) addition on texture, rheological and sensory properties of acid casein processed cheese sauces. Fibres used in production of sauces had an impact on the texture, viscosity, viscoelastic and sensory properties. The largest increase in viscosity was observed in products with addition of potato fibre, which have good water holding and adsorption capacity. Processed cheese sauce with the addition of citrus fibre was characterised by the highest values in general, and the increase of this feature in the tested samples was regular. Adhesiveness was the highest in products with 1% addition of every fibre. The lowest values of viscosity single shear, G′ and G″ moduli, among all tested, had sauces with acacia fibre. Moreover, they had the most thin liquid consistency, which was different from preferred one.     

江西赣州矿山废石酸化潜力

为了准确评价赣州矿山废石的产酸潜力，进行了净产酸试验、最大净产酸潜力试验和淋滤试验研究。研究结果表明：约一半矿山的废石样品具有酸化潜力，但净产酸量比较小，最大产酸量(H₂SO₄)仅为10 kg/t；赣州矿山废石含硫低，在酸雨作用下短期内不会全部酸化，但废石中的重金属元素均能溶出，其中Cd、Pb、Zn、Hg等重金属元素溶出量超标，污染周边环境。     

胶凝酸与交联酸一体化耐高温缓速酸研究

胶凝酸和交联酸是高温碳酸盐岩酸压常用的缓速酸体系，该体系存在耐温能力不足、配伍差等问题，同时现场交联酸和胶凝酸为不同酸液体系，存在配制使用流程繁琐的问题。为解决上述问题，优化形成了一体化酸液体系，交联酸基液可作为胶凝酸使用，加入交联剂作为交联酸使用。交联酸配方为:20%盐酸+1%稠化剂SRAP-2+2.5%高温缓蚀剂主剂SRAI-1+0.5%增效剂+1%酸压用铁离子稳定剂SRAF-1+1%酸压用破乳剂SRAD-1+1%交联剂SRAC-2A和延迟交联剂SRAC-2B（2:12）。胶凝酸在160℃、170 s-1下，恒温剪切120 min后黏度为20 mPa·s。交联酸体系交联时间为93 s，具有良好的延迟交联特性；在160℃、170 s-1下恒温剪切90 min后黏度为55 mPa·s，一体化酸液体系室温可放置10 d以上，在140℃动态腐蚀速率为46.1021 g/（m2·h）。研究结果表明，该体系可满足高温储层对缓速酸的要求，实现酸液体系一体化，方便现场施工，具有较好的发展前景。      

3种油脂酸价测定方法的比较

目的研究现行国标中3种油脂酸价测定方法对不同类别植物食用油的检测效果。方法选取花生油、大豆油、玉米油、葵花籽油、菜籽油、橄榄油共6种油样采用这3方法进行酸价测定,通过分析测试结果和存在问题,提出不同测定方法的较佳适用对象和选择依据。结果6种油脂都是冷溶剂自动电位滴定法的平行测定标准差最小,热乙醇指示剂滴定法次之,冷溶剂指示剂滴定法的方差都较大。结论冷溶剂自动电位滴定法通用性最好;冷溶剂自动电位滴定法稳定性最好,热乙醇指示剂滴定法次之,冷溶剂指示剂滴定法的稳定性相对较差。     

Preconcentration of yoghurt base by ultrafiltration for reduction in acid whey generation during Greek yoghurt manufacturing

The feasibility of applying ultrafiltration (UF) to concentrate a yoghurt base prior to fermentation during Greek yoghurt manufacturing was studied as a way of minimising acid whey (AW) generation. Two Greek yoghurts were prepared by concentrating a milk base through UF to 13.8% and 17.5% (w/w) (GY‐2, GY‐3). Production of GY‐3 resulted in zero AW discharge, while the GY‐2 production discharged 78% lower AW compared to the control (GY‐1). GY‐2 exhibited a hard gel structure, low syneresis, maximum viscosity properties and a high protein and fat content. Applying both, UF and straining, resulted yoghurts with required structural attributes while substantially reducing the generation of AW.     

Synergistic effect on hydrolytic sodium borohydride adding waste Al for hydrogen generation

Synergistic effect of sodium borohydride (NaBH₄) mixed with waste aluminum in hydrolytic system were investigated to improve the hydrogen generation (HG) efficiency. The alkaline aqueous originated from NaBH₄ hydrolysis impels the passive aluminum hydroxide film of Al surface to be dissolved, thus, mutual effect of HG amount increasing by 88% and 50% for Al powder and waste Al can, respectively. To add acid catalyst in the mutual mixture system prompts to significantly accelerate HG rate from 100 ml/min˙g to 400 ml/min˙g but raising temperature is not obviously found. It is speculated that exothermic effect dominates the NaBH₄ hydrolytic reaction and eliminates the temperature effect. In this study, the mutual hydrolyzed reaction of NaBH₄ and waste Al provides ecofriendly environment, low cost and enables to achieve higher HG rate and further uses for portable/mobile fields.