木薯羧甲基淀粉对铜离子的吸附性能

采用搅拌球磨机对木薯淀粉进行机械活化,以活化60 min的木薯淀粉为原料,干法合成羧甲基淀粉吸附剂。考察羧甲基淀粉的取代度、溶液的pH值、Cu2+的初始浓度、吸附时间、羧甲基淀粉的投加量等因素对羧甲基淀粉吸附Cu2+性能的影响。结果表明,该羧甲基淀粉对Cu2+有很好的吸附作用;用取代度为0.841的羧甲基淀粉处理含Cu2+的废水,在pH=7.0、羧甲基淀粉的投加量50.00 mg/L、吸附时间15 min时,羧甲基淀粉对废水中Cu2+的吸附率高达98.80%,处理后的水质达到国家污水综合排放标准(GB8978-1996)中一级标准要求。     

交联羧甲基壳聚糖对铅离子的吸附研究

以壳聚糖为原料,先在氨基上引入羧甲基制备出N-羧甲基壳聚糖,再和环氧氯丙烷发生交联反应,合成出新型交联羧甲基壳聚糖,FTIR表征其结构。研究了交联羧甲基壳聚糖对Pb2+的吸附性能,探讨了交联剂用量、铅离子溶液的pH值、温度、吸附时间等因素对其吸附性能的影响,并考察了交联羧甲基壳聚糖对铅离子吸附动力学和热力学实验。实验结果表明,交联羧甲基壳聚糖对铅离子的吸附量优于壳聚糖,平衡吸附量可达297.6 mg/g。交联羧甲基壳聚糖对铅离子的吸附符合准二级动力学模型和Langmuier等温吸附,吸附主要依靠结构中的羧基和氨基基团。     

新型交联羧甲基葡甘聚糖凝胶球对尿素的吸附性能

本文用CuSO4溶液处理羧甲基葡甘聚糖制得了一种新型吸附材料—羧甲基葡甘聚糖铜凝胶球,研究了该凝胶球对尿素的吸附性能。分别考察了吸附时间、羧甲基葡甘聚糖浓度、CuSO4浓度、pH值、温度和尿素浓度对吸附的影响,同时用红外光谱初步表征了Cu2+交联羧甲基葡甘聚糖凝胶球-尿素复合物的结构。结果表明:310K时,凝胶球对尿素的吸附反应在9h时达平衡。当羧甲基葡甘聚糖浓度为2%,Cu2+质量分数为2%,尿素浓度为800mg.L-1时,pH值为6.5,吸附量为101.85mg.g-1。根据不同温度下凝胶球吸附尿素的等温线,计算了吸附过程的热力学参数,同时用Freundlich方程对实验数据进行了拟合,发现该方程适用于所研究的吸附体系。该体系为自发放热过程,体系熵减少,降温有利于吸附。     

交联羧甲基壳聚糖微球的制备及其对Pb2+的吸附性能

交联羧甲基壳聚糖微球的制备及其对Pb2+的吸附性能     

交联羧甲基魔芋葡甘聚糖空心微球制备及应用

以魔芋葡甘聚糖(KGM)为壁材,通过羧甲基化并经乳状液化学交联制备球体较为完好的羧甲基魔芋葡甘聚糖(CMKGM)空心微球.通过扫描电镜(SEM)和透射电镜(TEM)对CMKGM空心微球的形貌和粒径进行了表征.结果表明,KGM溶胶浓度为0.5%-1%、乳化剪切速率为8000r/min、环氧氯丙烷(ECH)为5ml时,可以得到粒径均匀、形貌规整、溶胀性能良好的CMKGM空心微球.增大溶液的pH和羧甲基试剂的用量均有利于CMKGM空心微球对水中Cu2+的吸附.     

交联羧甲基罗望子胶对Pb~(2+)的吸附研究

以罗望子胶原粉(TKP)为基料,氯乙酸钠(SMCA)为羧甲基醚化剂,环氧氯丙烷(ECH)为交联剂制备了取代度(DS)分别为0.42,0.64和0.88的3种交联羧甲基罗望子胶(CCMTKP),探究其对水溶液中Pb2+的吸附行为。结果表明,适宜吸附的pH值范围为2~6;吸附剂较佳用量为0.5%;3种CCMTKP对Pb2+的吸附在15min内达到平衡,遵从二级动力学方程;吸附符合Langmuir等温吸附模型,CCMTKP对Pb2+的最大吸附量为131.58mg/g;再生后的CCMTKP吸附性能良好,脱附百分率高,有望作为Pb2+的吸附剂使用。     

交联淀粉微球对Co~(2+)吸附行为的研究

以可溶性淀粉为原料,采用反相悬浮聚合得到交联淀粉微球(Cross-linked starch microspheres CSMs),考察其在不同介质中对Co2+的静态吸附行为及其对不同金属离子的吸附选择性,测定了淀粉微球对Co2+的吸附等温线,分析了其吸附的动力学特征。用红外光谱仪和X射线衍射仪对CSMs及其吸附产物的结构特征进行了对照分析,探讨了吸附机理。在实验条件下,CSMs对Co2+的吸附模式同时符合Langmuir和Freundlich等温方程,表观吸附速率常数k308K为0.0686min-1。CSMs对Co2+的吸附作用破坏了CSMs的结晶结构。交联淀粉微球对Co2+具有较好的选择吸附性,吸附量受介质种类、浓度的影响。这些结果为含钴废水的处理及金属离子吸附分离提供了有益的帮助。     

不同Ca/P摩尔比碳羟基磷灰石对Cu2+的吸附特性

利用废弃蛋壳为原料、尿素为添加剂,合成不同Ca/P摩尔比的碳羟基磷灰石(CHAP)用于吸附水中Cu2+,利用红外光谱、扫描电子显微镜、X射线能谱测试技术对CHAP样品表面化学进行了表征,考察了环境因子pH值、温度对CHAP吸附Cu2+的影响. 结果表明,通过改变尿素用量可以增加CHAP的Ca/P,提高其比表面积,Ca/P越高的CHAP,吸附能力越强. Ca/P为1.80的CHAP,在pH=7、温度40 ℃、反应时间为60 min时,其对Cu2+吸附量高达37.66 mg/g. 随着CHAP的Ca/P比增大,CHAP对Cu2+吸附的固相-水相分配系数也增大,对吸附量增大很有利.     

交联羧甲基壳聚糖吸附痕量汞研究

研究了交联羧甲基壳聚糖对Hg2 的吸附作用,探讨了溶液的pH值、反应时间、温度、样品体积、共存组分等因素对其吸附性能的影响.实验表明,在pH=5时,羧甲基壳聚糖对Hg2 的吸附性能很好,吸附率可迭95%以上,并且具有良好的重复使用性能,其吸附行为满足Langmuir等温式,饱和吸附容量为125.1mg/g,方法的相对标准偏差为7.8%.用于分析实际水样时,回收率达96～以上.     

一种羧甲基葡甘聚糖钛凝胶球的吸附性能

用钛交联羧甲基葡甘聚糖制得羧甲基葡甘聚糖钛凝胶球,研究该凝胶球对十二烷基苯磺酸钠(SDBS)的吸附性能。分别探究了吸附时间、p H值、Ti(SO_4)_2浓度、羧甲基葡甘聚糖(CMKGK)浓度、SDBS浓度及温度对吸附的影响。结果表明:Ti(SO_4)_2浓度为2%、CMKGM浓度为2%时制得的凝胶球吸附效果最佳,吸附反应在8h达到平衡,当SDBS溶液的pH值为4、初始浓度为2 000 mg·L~(-1),温度为298K时,凝胶球对SDBS的吸附量达到493 mg·g~(-1),而且吸附量随着SDBS溶液初始浓度的增大而增大。钛交联羧甲基葡甘聚糖凝胶球对SDBS的吸附符合Freundlich等温方程,升高温度不利于吸附。动力学研究表明此吸附遵从准二级动力学方程。     

Exposure of granular starches to low-pressure glow ethylene plasma

Polymerization of ethylene was initiated by low-pressure glow plasma generated in this gas. Depending on starch present in this plasma polymerization could be considered either as graft-polymerization of ethylene onto starch or homopolymerization. Result of the treatment of cassava, corn, potato, rice Indica, sweet potato, and waxy corn starches with ethylene plasma was analyzed by means of high-performance size exclusion chromatography, X-ray powder diffraction, thermogravimetry, digestion with β-amylase, and scanning electron microscopy. Analyses suggested that graft-polymerization occurred on sweet potato and rice starch. With other starches homopolymerization of ethylene on granules took place.     

A potential bacterial carrier for bioremediation

One of the limiting factors to the effectiveness of biostimulation and bioremediation is the loss of inoculated material from the site. This can occur by a number of pathways, but is particularly problematic in open water systems where the inoculated material is simply lost in the water. It is desirable to develop new material, a matrix, within which bacteria and/or biostimulants can be incorporated. We have investigated the basic physical properties of insoluble potato starch to eventually evaluate its use as such a matrix. Insoluble starch fibers were prepared from white potato (Solanum tuberosum) and sweet potato (Ipomoea batatas) and were compared for their melting temperature by DSC and their ability to bind/aggregate bacteria. The DSC curves for white and sweet potato showed that the melting temperature is 127.34 and 133.05°C for white and sweet potato fibers, respectively. The TG curves for white and sweet potato starches exhibited one main mass loss step corresponding to the DTG peak temperature at 323.39 and 346.93°C, respectively. The two types of fibers, however, showed different binding/aggregation capacities for bacteria, with white potato approximately twice as many cells of Burkholderia cepacia (22.6 billion/g) as cells of Pseudomonas putida. The reverse was true for fibers from sweet potato, binding twice as many cells of Pseudomonas putida (23 billion/g) as cells of Burkholderia cepacia.     

Gelatinization properties of native starches and their Näegeli dextrins

Cassava, potato, sweet potato, and Peruvian carrot starches were hydrolyzed with 15% v/v sulfuric acid solution for up to 30 days. Näegeli dextrins obtained from 1, 3, 6, 12, and 30 days were evaluated using differential scanning calorimeter (DSC) and scanning electron microscopy (SEM). Two phases of hydrolysis were found. The first phase was attributed to faster degradation of amorphous areas of granules, whereas the second phase corresponded to slower degradation of crystalline regions. Peruvian carrot starch was the most susceptible to acid, whereas potato and sweet potato starches were the most resistant. From DSC, it was observed a progressive reduction in peak height and a broadening of peaks with increasing hydrolysis time. The peaks shifted to higher temperatures. Onset temperature decreased on first day of hydrolysis for cassava and Peruvian carrot starches, and on third day for potato and sweet potato. Enthalpy decreased during first stage of hydrolysis in cassava and Peruvian carrot starches, and during second phase, it reduced in all starches. SEM showed that the granule surfaces were degraded by erosion on the first day of treatment, followed by degradation of amorphous areas. On third day, potato and sweet potato starches still displayed some granules almost intact, whereas cassava and Peruvian carrot starch granules were totally degraded, confirming their high susceptibility to acid attack. On sixth day of hydrolysis, starch granules had faceted structures, characteristic of crystalline material. The effect that acid hydrolysis had on thermal properties of starches depended on both hydrolysis stage and starch source.     

Heat-moisture treatment (HMT) on blends from potato starch (PS) and sweet potato starch (SPS)

Journal of Thermal Analysis and Calorimetry - Samples of potato starch (PS), sweet potato starch (SPS) and their binary mixtures, with moisture levels of 10, 15 and 20% (db), were submitted to...     

A comparative study of structure,thermal degradation,and combustion behavior of starch from different plant sources

The present study investigated the structure, degradation properties, and combustion behavior of starch from maize, sweet potato, lotus root, and tobacco. Compared with other plant starches, tobacco starch had the smallest size, the highest amylose content and the least crystallinity. Microscale combustion calorimetry (MCC) experiment demonstrated that sweet potato starch showed the maximum peak heat release rate value (888.0 W g^?1) while tobacco starch showed the minimum value (316.0 W g^?1) and thermogravimetric analysis coupled with Fourier transform infrared spectrometer (TG-FTIR) results showed tobacco starch had good char formability (residue mass: 15.6%) and released more incombustible gaseous products, such as H₂O and CO₂. These results suggest that the thermal properties of plant starches were mainly influenced by the structural features and amylose content, especially the amylose ratio, and tobacco starch was very promising for application in green flame-retardant material.     

用酶分解法研究淀粉糊化

本文用酶分解法对土豆、甘薯和玉米三种淀粉,在不同条件下的糊化作了研究。得出了三种淀粉开始和完全糊化的温度和时间;测定了糊化反应的动力学,并从糊化温度与反应速度常数的关系,计算了各种淀粉糊化的活化能,还根据Vant Hoff公式计算了三种淀粉糊化的有效热焓变化。     

交联阳离子淀粉(DS=0.95)的干法制备及其脱色性能

在碱催化剂BZ－1存在下，以N－（2，3－环氧丙基）三甲基氯化铵（GAT）为阳离子化试剂，干法制备了交联高取代度季铵型阳离子淀粉。对制得阳离子淀粉的脱色性能研究结果表明，交联高取代率阳离子淀粉对活性染料具有优异的脱色效果。     

海藻酸钠/羧甲基淀粉共混膜

用溶液共混法成功制备出海藻酸钠／羧甲基淀粉共混膜，IR、XRD、SEM结构表征以及力学性能、吸水性和水蒸汽透过率测定结果表明：共混膜中海藻酸钠和羧甲基淀粉间存在强烈的分子间氢键等相互作用及良好的相容性；随羧甲基淀粉含量的增加，共混膜的吸水率显著降低；当羧甲基淀粉含量(wCMS)=0．20时，共混膜的抗张强度和断裂伸长率分别为53．1MPa和5．3％，比海藻酸钠膜分别提高了97．4％和60．6％，水蒸汽透过率达最小值，是一种具有潜在应用前景的可食性包装膜材料。     

Production of single-cell protein with two-step fermentation for treatment of potato starch processing waste

Potato starch processing waste is causing serious environmental problems. This study aimed to convert potato starch processing waste into single-cell protein as high-quality feed using a two-step fermentation process. The mutant strain Aspergillus niger H3 was selected after UV irradiation and ethyl methyl sulfone mutagenesis for more cellulase production. The activities of sodium carboxymethyl cellulase and filter paperase of strain H3 were 8.86 and 4.79 U, respectively, which were much higher than the parent strain (1.18 and 0.62 U). After treatment with strain H3, the cellulose degradation rate of potato residue was 80.54 %. A liquid fermentation using Bacillus licheniformis was performed as the second step. The optimized fermentation conditions were temperature of 32.8 °C, pH 6.67, and inoculum concentration of 1.78 % using the response surface method. Results of this study showed a potential application in large-scale industrial conversion.