Assessment of ponds surrounding Imphal Valley on the basis of various biological and physicochemical parameters

The water quality is one of the major criteria for the environmental evaluation based on the parametric changes in the physicochemical and biological properties of water. The distribution patterns of physicochemical and biological characteristics of the various rivers in the Imphal Valley have been studied in this work. The objective of the work is to determine the surface water quality of Imphal Valley to assess its suitability for domestic purposes. The physicochemical parameters of water such as water temperature, pH, hardness, alkalinity, EC, TDS, chloride, calcium, magnesium, sodium, potassium and nitrate were analysed for the experimentation. The biological characteristics were estimated from the Total coliform and Escherichia coli content of water. The physicochemical parameters were within the acceptable limits on the other hand Total coliform, and E. coli values were exceeding from the acceptable and permissible limits as prescribed by Bureau of Indian Standards (BIS). The study suggests untreated domestic disposal from market and household to the water body causes heavy pollution in rivers of Imphal Valley.     

Non-cyanide Leaching Processes in Gold Hydrometallurgy and Iodine-Iodide Applications: A Review

Gold is one of the most important sources of currency entry in the economics of any state. Besides mining raw materials, fit for effective gold extraction, residues of gold extraction factories are the source of this precious metal. Moreover, the role of industrial wastes, which has a rich source of nonferrous and noble metals, increases. Processing expediency of complicated wastes is determined by their harmful ecological influence on the environment. Involving to processing of gold, the enumerated sources demands the use of high leading technologies, taking into account the variety of their composition. One of the ways of increasing effectiveness of processing the gold-containing materials may be introduction of direct hydrometallurgy processes. Hydrometallurgical methods of processing differ in low power capacity, simplicity of implement process, decreasing pollution of the environment. It is necessary for this not only to sort out selective solvents, but also to elaborate methods of regeneration and recycling of the used solutions and solvents. At present leaching of gold-containing raw materials by cyanide is the main hydrometallurgical process and the main advantage of cyanide is high selectivity with regard to gold. However, leaching by cyanide solutions has a set of substantial drawbacks: process duration, high cost of the reagent, nonadaptability of “stubborn” ores and concentrates, absence of possible regeneration of cyanide solutions and the main thing is high toxicity of cyanide compounds. Therefore elaboration of new hydrometallurgical methods of extracting gold using selective nontoxic reagents, in particular, iodine solutions is important scientific and practical task.     

响应面优化浓香菜籽油超声辅助酶法脱胶工艺研究

为了优化浓香菜籽油超声辅助酶法脱胶工艺,以浓香菜籽原油为原料,以磷脂含量为考察指标,通过单因素试验探究酶添加量、反应时间、反应温度、pH、水添加量以及超声功率对浓香菜籽油脱胶效果的影响。在此基础上,利用响应面法优化浓香菜籽油超声辅助酶法脱胶工艺。同时,对传统酶法脱胶与超声辅助酶法脱胶的脱胶效果进行了对比。结果表明：浓香菜籽油超声辅助酶法脱胶最优工艺条件为酶添加量45 mg/kg、反应时间3 h、反应温度55℃、pH 5.0、水添加量2.5%、超声功率490 W,在此条件下浓香菜籽油的磷脂含量为0.05 mg/g,脱胶率可达99.4%;超声辅助酶法脱胶效果优于传统酶法脱胶。可见,超声辅助酶法脱胶是一种较为高效的油脂脱胶方法。     

哈萨克斯坦油脂油料生产、加工和贸易情况分析

中国是一个油脂油料资源严重短缺的国家,一直以来60%以上食用油依赖进口,且食用油缺口是未来很长一段时间需要面对的问题。受贸易摩擦和新冠肺炎疫情叠加影响,中国急需寻找新的油脂油料合作伙伴,拓宽进口渠道。哈萨克斯坦是“一带一路”经济带上油脂油料生产大国,与中国贸易基础深厚。通过对哈萨克斯坦2014—2018年油料作物种植面积和油脂油料产量、进出口情况的分析,认为哈萨克斯坦油脂油料产业发展迅速,油料种植面积和生产能力持续增加,油脂加工潜力巨大。这为中国与哈萨克斯坦油脂油料贸易合作奠定了良好基础。     

Features of Electrochemical and Conformational Behavior of Intergel System Based on Polyacrylic Acid and Poly-4-Vinylpyridine Hydrogels in an Aqueous Medium

The goal of work is study of polyacrylic acid hydrogel （gPAA） and poly-4-vinylpyridine hydrogel （gP4VP） remote interaction influence on their electrochemical and conformational properties. The dependences of the swelling coefficient, conductivity and pH of intergel systems aqueous solutions with different ratios polyacid：polybasis from times are considered. It is established that maximum conductivity is observed at ratios of gPAA：gP4VP 5：1, 3：3 and 1：5, while minimum conductivity is observed at ratios 4：2 and 2：4. Increasing ofmedium＇s pH is observed at ratio 1：5. Swelling coefficient ofpolyacrylic acid hydrogel increases monotonically with increase of poly-4-vinylpyridine share in an aqueous medium. In dependence of swelling coefficient from ratios polyacid：polybasis conformational transition region of poly-4-vinylpyridine is detected in area 3：3-1：5. The obtained results can be explained by remote interaction of polyacrylic acid hydrogel with poly-4-vinylpyridine hydrogel, during which mutual activation of hydrogels occurs due to proton transfer from polyacid to polybasis.