淀粉黄原酸酯在水处理中的应用

淀粉黄原酸酯是一种金属络合剂,广泛应用于去除水环境体系中的重金属,主要分为水不溶性淀粉黄原酸酯（ISX）和水溶性淀粉黄原酸酯（SSX）两大类,本文着重综述了淀粉黄原酸酯的研究进展及其在水处理中的应用,介绍了国内外应用SSX和ISX处理污水中重金属的现状。     

交联淀粉黄原酸酯

一、概述交联淀粉黄原酸酯,即不溶性淀粉黄原酸酯(ISX),这里定义为经用交联试剂交联后再黄原酸酯化的淀粉。黄原酸酯化是在强碱(通常是氢氧化钠)存在下进行的,黄原酸基团具有一元酸的性质,因制备时在强碱性介质中,产品呈现以盐的形式,可以用下列通式来表示。     

利用蔗渣或稻草制备重金属废水处理剂—纤维素黄原酸酯的试验

本文研究了甘蔗渣和稻草制备黄原酸酯的合成工艺,并应用合成的纤维素黄原酸酯进行重金属废水处理,结果表明实验合成的黄原酸酯是一种优良的重金属废水处理剂。     

除去水中有害金属离子的简单方法

最近发现不溶于水的玉蜀黍淀粉的黄原酸酯,能从废水中除去有害的金属离子,如铜、镍、镉、铅、锌、汞(以上两价离子)及铬(三价离子),效果很好,金属离子的残留量能达到美国国家排放标准以下,方法简单可行。 用玉蜀黍淀粉黄原酸酯处理含铜离子废水的结果:铜离子浓度31.77毫克/升废水中加     

不溶性淀粉黄原酸酯的制备

本文以玉米淀粉为原料,环氧氯丙烷为交联剂,二硫化碳为酯化剂,制备了不溶性淀粉黄原酸酯。研究了氢氧化钠用量、二硫化碳用量、硫酸镁用量、反应温度和反应时间对不溶性淀粉黄原酸酯硫含量的影响,通过正交试验得出不溶性淀粉黄原酸酯最佳制备条件为：二硫化碳用量31．5％,NaOH用量20％,反应时间2．5h,反应温度35℃,硫酸镁用量20％,在此条件下,不溶性淀粉黄原酸酯硫含量为6．34％。     

木薯淀粉黄原酸酯制备

以木薯淀粉为原料,研究环氧氯丙烷用量、二硫化碳用量、反应时间、硫酸镁用量等因素对淀粉黄原酸酯吸附银离子能力影响。通过正交试验,确定对木薯淀粉黄原酸酯吸附性能影响能力大小依次为:环氧氯丙烷>反应时间>二硫化碳>硫酸镁;且最优制备工艺制得木薯淀粉黄原酸酯对银离子吸附率可达97.9%。     

交联淀粉黄原酸酯的制备及其处理废水的研究

以淀粉为原料,环氧氯丙烷为交联剂,二硫化碳为酯化剂,制备不溶性交联淀粉黄原酸酯。结果表明交联淀粉的最佳操作工艺条件为:玉米淀粉20 g、0.2 g/m L Na OH溶液5.0 m L、环氧氯丙烷4.0 m L、反应温度30℃、反应时间2.5 h。交联淀粉黄原酸酯的最佳合成工艺条件为:交联淀粉10 g,0.2 g/m L的Na OH溶液20 m L,5 m L CS2,温度50℃,反应时间1.0 h。交联淀粉黄原酸酯净化生活废水试验结果表明:在10 m L生活废水中,投加0.7 g淀粉黄原酸酯时,废水吸光度达到最小;当其他条件一定时,生活废水p H约为7、反应时间为40 min时,吸附效果较佳。     

变性淀粉的种类及其应用研究(续)

2.4淀粉酯 淀粉分子中含有丰富的羟基,羟基的存在就可以和酸发生酯化,生成淀粉酯.在淀粉分子中有三个游离的羟基,因此可以形成单酯、双酯和三酯化合物.淀粉酯分为无机酸酯和有机酸酯两类.其中用途最大的淀粉无机酸酯是淀粉磷酸酯和淀粉黄原酸酯;淀粉有机酸酯最主要的是淀粉醋酸酯.     

阳离子交联淀粉黄原酸酯的制备研究

以天然淀粉为原料,以环氧氯丙烷为交联剂,制备交联淀粉,在此基础上,以GTA为醚化剂、二硫化碳为酯化剂,制备了阳离子交联淀粉黄原酸酯。实验结果表明:交联淀粉的操作工艺条件影响因素顺序为:氢氧化钠用量环氧氯丙烷用量反应时间反应温度;阳离子交联淀粉黄原酸酯的操作工艺条件影响因素顺序为:二硫化碳用量反应时间反应温度氢氧化钠用量,其最佳工艺条件为氢氧化钠加入量20 m L,反应温度40℃,二硫化碳加入量5 m L,反应时间2h。含6.0μg/m L Cr6+的模拟废水经阳离子交联淀粉黄原酸酯处理后,其最小吸光度为0.1892,此时Cr6+最大清除率可达62%以上。     

变性淀粉的种类及其应用研究(续)

2.4淀粉酯淀粉分子中含有丰富的羟基,羟基的存在就可以和酸发生酯化,生成淀粉酯。在淀粉分子中有三个游离的羟基,因此可以形成单酯、双酯和三酯化合物。淀粉酯分为无机酸酯和有机酸酯两类。其中用途最大的淀粉无机酸酯是淀粉磷酸酯和淀粉黄原酸酯;淀粉有机酸酯最主要的是淀粉醋酸酯。淀粉醋酸酯又称乙酰化淀粉或乙酸淀粉。早在1900年前后淀粉醋酸酯就开始进行实用化尝试,当时是为了替代乙酸纤维素,人们感兴趣的是取代度为2～3的淀粉醋酸酯,因为它们具有溶剂溶解性(如丙酮、氯仿中)及热塑性。目前,在欧美、日本等国,工业产品是取代度从0.01～…     

Synergetically Acting new Flocculants on the Basis of Starch‐graft‐Poly(acrylamide)‐co‐Sodium Xanthate

A synergetically acting new flocculant on the basis of starch‐graft‐poly(acrylamide)‐co‐sodium xanthate (CSAX) was synthesized by grafting copolymerization of crosslinked corn starch, acrylamide (AM), and sodium xanthate, using epichlorohydrin (EPI) as cross‐linking agent and ceric ammonium nitrate (CAN) as polymerization initiator in aqueous solution. The effects of some factors, such as crosslinker, initiator, AM, NaOH, on the %Tr (turbidity removal rate), %Trd (turbidity removal rate of a water sample which has both turbidity and heavy metal ions %Hr (heavy metal ion removal rate) and %Hrd (heavy metal ions removal rate of water which has both heavy metal ions and turbidity), are investigated. As proven by FTIR and elemental analysis, the CSAX can be successfully synthesized and can remove both turbidity‐causing substances and heavy metal ions from aqueous solutions. Under optimum synthesis conditions CSAX exhibits excellent performance, i.e. %Tr = 98%, %Trd = 98.4%, %Hrd = 99% and %Hr = 91.6%, respectively.     

Oxidation of Insoluble Starch Xanthate: Stabilization and Metal Ion Removal

Insoluble starch xanthate was oxidized with hydrogen peroxide or other oxidants to give insoluble starch xanthide. The effect of temperature, pH and quantity of hydrogen peroxide for product formation was determined. Insoluble starch xanthide was found to be more stable at room temperature than the xanthate; however, it was still effective in removing heavy metal ions from water.     

Preparation and Properties of Oxidatively and Zinc Coupled Starch Xanthates

Conditions for the precipitation of sodium starch xanthate as the zinc salt were determined to be: xanthate degree of substitution greater than 0.02 and zinc ion concentration of 0.005–0.015-M. As xanthate ion concentration is increased, less zinc is required for complete precipitation of the starch xanthate. Oxidatively crosslinked starch xanthates (starch xanthides) were more stable when washed with dilute acid before drying. Shelf-life was greatly improved when the moisture content of the samples was less than 5%. Starch xanthides rapidly decompose in water. Pyrolysis of starch xanthides at temperatures of 145 to 215°C liberates carbon disulfide and carbonyl sulfide.     

Derivatives of High-Amylose Starch Xanthate in Rubber. Influence of Amylose Content of Starch Upon the Water Resistance of Starch-Reinforced Styrene-Butadiene Rubbers

Crosslinked low-amylose (0 or 28%) starch xanthates used as reinforcing materials in styrenebutadiene elastomer imparted better dry tensile properties than their high-amylose (55, 68 or 82%) analogues. After immersion in water for 70h the tensile strength of low-amylose starch reinforced vulcanizates deteriorated considerably while high-amylose starch reinforced vulcanizates changed little or not at all. Such variables as xanthate degree of substitution and starch loading influenced curing time and properties. Mode of crosslinking the xanthate significantly affected retention of starch in the coprecipitate, and produced significant variations in curing characteristics, and in such properties as compression set, set at break before immersion in water and tensile strength after water immersion. The method of drying affected compressions set and modulus.     

海产品中重金属脱除的研究进展

近年来由于土壤、河流、海洋中重金属污染日益严重,我国海产品普遍出现有害重金属超标的问题,严重影响我国海产品的食用和药用安全。因此,脱除海产品中有害重金属的研究受到广泛关注。本文着重综述了两种海产品中有害重金属脱除的方法：活体重金属净化法和蛋白酶解液重金属脱除法,同时提出了海产品中有害重金属脱除方法研究的新趋势。     

Synthesis and Physicochemical Studies of Starch-Sulphonated Phenol Formaldehyde Cationic Exchangers

A new cationic exchanger was synthesized through a complex system involving reactions of starch or modified starches, phenol and formaldehyde in presence of HCl, followed by sulphonation using sulphuric acid. Major properties of these resins including exchange capacity, swellability, solubility, ability to remove heavy metals were studied and compared with those of sulphonated phenol formaldehyde resin. This was done to signify the importance of the presence of the starch or the modified starches in the backbone of the resin. Tentative mechanisms for the reactions involved in the synthesis of such cation exchangers is also reported.     

水产品中三种常见重金属污染物的毒性及风险评估进展

我国是水产品养殖和消费大国,重金属污染是水产品安全面临的主要问题之一。含重金属的工业废水经河流排放到水域水体中,并且在水底的沉积物中沉积,造成养殖环境污染。而后经过食物链富集到生物体内,对水生生物本体和食用受污染水产品的人类都会引起健康问题。本文综述了近几年水域水体和沉积物中的重金属污染研究现状,并对污染严重的Cd、As、Pb三种重金属的毒性进行了概括,最后总结了现今对水产品风险评估的主要方法和研究现状。通过本文所引用文献分析,对比水体中的重金属污染,沉积物中的污染程度较大,多具有中等生态风险,故对水产品重金属污染影响较大。重金属对人体和水产品均有很强的毒性作用,根据众多风险评估研究结果表明,水产品重金属超标的情况仍较普遍,单因子污染指数和风险熵指数绝大多数小于1,无潜在健康风险,但依然存在高复合性污染的情况。     

改性淀粉絮凝剂研究进展

改性淀粉絮凝剂因具有无毒、选择性大、原料来源丰富、价格低和易于生物降解等优点而越来越受到人们关注。该文介绍阳离子淀粉、不溶性交联淀粉黄原酸酯、接枝淀粉、羧甲基淀粉和复合改性淀粉等改性淀粉絮凝剂的制备、功能和絮凝剂研究情况,重点论述接枝淀粉和阳离子淀粉两类改性淀粉絮凝剂,为今后改性淀粉絮凝剂开发指明方向。     

Insoluble Starch Xanthate: Preparation,Stabilization, Scaleup and Use

The addition of magnesium sulfate to xanthation mixtures of crosslinked starch aided isolation, scaleup and room-temperature product stability on storage. Pilot-plant scaleup of laboratory-developed procedures also yielded water-insoluble products effective in removing heavy metals from water. Several different processing methods are presented to show the ease of preparation and use of the products.     

Crosslinking of Starch Xanthate IV. Epoxy Resin and Diepoxide Thickeners for Xanthate and Starch

Aqueous solutions of starch xanthate (of varying degree of substitution), butanediol dixanthate or alkali-gelatinized starch were reacted with a diepoxide, such as butanediol diglycidyl ether to get viscous gels. Epoxy resins were likewise reacted with xanthate to form viscous media. Alkaligelatinized starch of varying alkali ratio content similarly produced gels with diepoxides. Solids were precipitated from the gels and their compositions were deduced from their elemental contents and infrared spectra.