阳离子型聚丙烯酰胺絮凝剂的开发与煤气化黑水处理

煤气化过程产生的黑水通常采用絮凝处理去除悬浮物及部分有机物后循环使用。以丙烯酰氧乙基三甲基氯化铵为阳离子单体,以氧化还原类和偶氮类引发剂为复合引发剂,采用水溶液自由基共聚法制备了一种适用于黑水絮凝处理的阳离子型聚丙烯酰胺。实验结果表明：引发温度为15~20 ℃时,聚合反应较为平稳,1 h后聚合反应结束,于60~80 ℃干燥,得到产品相对分子质量较高,达（734~1 086）×10⁴;采用该絮凝剂絮凝处理黑水时,絮体大、沉降速率快,絮凝沉降效果佳;在煤气化装置黑水工况温度下,絮凝剂投加量为3 mg/L时,黑水中悬浮物质量浓度可从114 mg/L降至30 mg/L以下,满足现场使用要求。     

聚丙烯工业废水排放的治理措施

在利用间歇式液相本体法工艺生产聚丙烯时,易产生大量废水,包括闪蒸水环真空泵排放水、聚合釜轴封冷却水排放水、聚合升温用热水罐溢流水等。应最大限度地减少废水的排放量。已经采取的废水减排措施包括:对于真空泵逐渐调小供水量(即减少了排放量);将轴封冷却水收回重复利用;维持热水罐的水位稳定,避免产生溢流。采取上述措施在满足生产要求的同时,最大限度地减少了废水排放量。     

Changes in Physical and Biological Soil Quality Indicators in a Tropical Crop System (Havana,Cuba) in Response to Different Agroecological Management Practices

The objective of our study was to assess the response of physical (aggregate stability and bulk density) and biological (enzyme activities and microbial biomass) soil quality indicators to the adoption of agroecological management practices, such as the planting of forage species (forage area) and the rotation of local crops (polycrop area), carried out in a representative tropical pasture on an integrated livestock–crop farm. The pasture system was used as control (pasture area). In all three areas, the values of water-soluble C were higher in the rainy season compared to the dry season. Pasture and forage areas had the highest percentage of stable aggregates in the rainy season, while polycrops developed soils with less stable aggregates. Soil bulk density was lower in the pasture and forage areas than in the polycrop area. In the pasture area, the microbial biomass C values, dehydrogenase, urease, protease-BAA, acid phosphatase, and -glucosidase activities were higher than in the forage and polycrop areas, particularly in the dry season. The highest increase in the microbial biomass C in the rainy season, with respect to the dry season, was recorded in the pasture area (about 1.2-fold). In conclusion, the planting of forage species can be considered an effective practice for carrying out sustainable, integrated livestock–crop systems, due to its general maintenance of soil quality, while the adoption of polycrop rotations appears to be less favorable because it decreases soil quality.     

Biosynthesis of poly-(R)-3-hydroxyalkanoate: An emulsion polymerization

Poly-(R)-3-hydroxyalkanoates (PHAs) are bacterial storage polyesters, which are accumulated by a wide variety of microorganisms as a reserve of carbon and energy. Currently, these biopolymers are receiving much attention because of their potential application as biodegradable and biocompatible plastics. The polymer appears as submicron intracellular granules. The biosynthesis of these granules has been studied extensively but many observations remain inexplicable. This paper draws an analogy between the process of emulsion polymerization and that of granule formation. This analogy may explain many of the unknown features of granule formation and may also lead to useful applications of granules as latex products.     

白腐菌漆酶催化聚合造纸废水中木素的研究

为了证实漆酶对从造纸厂二沉池出水提取出的木素的催化聚合作用,研究了白腐菌采绒革盖菌Coriolus versicolor漆酶对木素聚合的影响。在有氧条件下,通过添加漆酶和少量ABTS介体到水样中,用紫外分光光度计测定了其中木素浓度变化,利用凝胶色谱法分析了酶催化聚合木素前后的分子量的变化。结果表明:酶处理6h以后,废水中木素浓度从93.1mg/L下降到17.2mg/L。酶处理2h以后,从造纸厂污水分离的木素的分子量从31251上升到58610。造纸废水中木素及其衍生物被聚合后通过絮凝沉淀除去,从而实现废水色度与COD降低,进而为造纸废水回用提供可能。     

一种船舶自修复防腐涂料的制备与表征

以脲醛树脂为囊壁、复合环氧树脂为囊芯,采用原位聚合法成功合成了脲醛树脂包覆环氧树脂体系微胶囊。采用扫描电子显微镜观察微胶囊的表面形貌,测量微胶囊的壁厚;利用红外光谱分析判定微胶囊壁材是否形成,芯材是否被完整包覆。结果表明,应用一步原位聚合法可以制备包覆完整、均匀分散、含有特殊芯材的微胶囊。合成的微胶囊形状基本呈球形,粒径分布均匀,平均粒径约为100μm;胶囊表面粗糙致密,粗糙表面主要是由纳米微胶囊沉积而成。微胶囊表面粗糙度的增加有利于增加微胶囊与基体的接触面积,改善微胶囊与基体的界面粘结力,从而提高自修复材料的修复效率。     

Insights into the changes of amino acids,microbial community,and enzymatic activities related with the nutrient quality of product during the composting of food waste

● The highest seed germination index was achieved at 0.3 g/g total solids of food waste. ● Proline was identified as the key amino acid related with the composting process. ● Amino acid metabolism sequences predominated during the whole composting process. This study systematically investigated the changes of amino acids as the composting process of food waste proceeded. It is found that the addition of 0.3 g/g total solids of food waste achieved the highest seed germination index of the product (268 %). The microbial community results indicated that the abundance of amino acid metabolism sequences remained at high levels during the whole composting process. Proline was identified as the key amino acid related with the nutrient quality of product during the composting of food waste. Further plant germination and hydroponic experiments found, that compared with those without the addition of proline, the addition of 50 mg/L proline increased seed germination rate by 20 %, increased shoot length by 3 %, increased root biomass of seedlings by 82 %, and increased leaf biomass of seedlings by 76 %, respectively. Firmicutes, γ-Pseudomonadota, Chloroflexi and Planctomycetes were the key identified bacteria related with the increase of proline during the composting of food waste. Meanwhile, the enzymatic tests of the activities of superoxide dismutase, peroxidase and malondialdehyde indicated that proline did not cause oxidative damage on the growth of plants. This study provided novel insights into the changes of amino acids, microbial community, and enzymatic activities related with the nutrient quality of product during the composting of food waste.     

水溶液中4-氯酚在光照下的矿化和聚合化

在光照条件下,４－氯酚溶液浓度随着光照时间的延长而降低,ＣＯ２的释放表明在４－氯酚光化学反应过程中存在矿化作用,通过光子相关光谱表征,确定反应体系存在聚合作用,聚合物具有荧光性。对反应体系进行ＵＶ、ＩＲ光谱表征,表明这一过程中存在腐殖化作用,有类腐殖质生成,聚合化与矿化相比较,前者是主要过程。     

纳米金修饰分子印迹聚合膜电极检测双酚A

以纳米金修饰玻碳电极为基础电极,以双酚A为模板分子,以邻氨基苯硫酚为聚合单体,采用循环伏安法电聚合制备分子印迹聚合膜,利用循环伏安和交流阻抗法研究电极的电化学特性。结果表明,双酚A在修饰电极表面的反应是一个受吸附控制的等电子、质子转移的不可逆反应。采用差分脉冲伏安法检测双酚A,线性范围为5. 0×10~(-6)mol/L～4. 0×10~(-4)mol/L,检出限为2. 3×10~(-7)mol/L。将该电极用于自来水和牛奶样品的测定,结果均为未检出,加标回收率分别为93. 5%和95. 4%,3次测定结果的RSD分别为4. 0%和5. 7%。     

Enzymatic Degradation of Poly(l-Lactic Acid): Effects of UV Irradiation

Amorphous and crystallized poly(l-lactic acid) (PLLA-A and PLLA-C, respectively) films were prepared, and the proteinase K-catalyzed enzymatic degradation of UV-irradiated and non-irradiated PLLA-A and PLLA-C films was investigated for periods up to 10 h (PLLA-A) and 60 h (PLLA-C). The molecular weights of both the PLLA-A and PLLA-C films can be manipulated by altering the UV irradiation time. The enzymatic weight loss values of the UV-irradiated PLLA films were higher than or similar to those of the non-irradiated PLLA film, when compared with the specimens of same crystallinities. UV irradiation is expected to cause the PLLA films to undergo chain cleavage (a decrease in molecular weight) and the formation of C=C double bonds. It seems that the acceleration effects from decreased molecular weight on enzymatic degradation were higher than or balanced with the disturbance effects caused by the formation of C=C double bonds. After enzymatic degradation, a fibrous structure appeared on the spherulites of the UV-irradiated PLLA-C film. This structure may have arisen from chains containing or neighboring on the C=C double bonds, which were enzymatically undegraded and assembled on the film surface during enzymatic degradation. The results of this study strongly suggest that UV irradiation will significantly affect the biodegradation behavior of PLLA materials in the environment.