沙雷氏菌发酵蓝藻生产蛋白酶

以富含蛋白质的蓝藻作有机氮源进行微生物发酵生产蛋白酶,为蓝藻的资源化利用提供一条新途径。采用单因素实验,研究了影响沙雷氏菌发酵蓝藻生产蛋白酶的培养基主要成分。结果发现,在实验范围内,沙雷氏菌发酵蓝藻生产蛋白酶的最佳碳源是蔗糖,最佳速效氮源是尿素,最佳金属离子(盐)是ZnSO4,最佳产酶促进剂是吐温80。在单因素实验中,发酵上清液的蛋白酶活最高可达到941 U/mL,而且发酵周期短,发酵培养18 h即可达到最高酶(活)值。     

PVDF/PMMA与PVDF/TPU共混膜抗污染性能研究及应用

观察新型五孔PVDF共混改性纤维膜SEM形貌特征,采用逐级通量法测定PVDF/PMMA和PVDF/TPU共混改性膜的临界通量,研究在次临界和超临界通量下A(PVDF/PMMA)与B(PVDF/TPU)2种管式膜组件的过滤和抗污染性能,并在次临界通量下处理地表水。结果表明,PVDF共混改性膜具有优良的微观结构,且膜B性能较好;膜A、B的临界通量分别为12 L/(m2.h)和10 L/(m2.h);膜组件B比膜组件A抗污染性能好。次临界通量下膜组件的运行比超临界通量下的稳定。与采用单独超滤处理某市地表水相比,2种膜组件采用混凝+超滤工艺的运行处理效果更好,且膜组件B比膜组件A处理效果佳。     

类水滑石衍生复合氧化物催化水解羰基硫的研究

采用共沉淀法制备了一系列的类水滑石衍生复合氧化物催化剂,利用正交实验设计对催化剂的制备条件进行了优化,研究了金属组合、合成pH、M2+/M3+、二价金属比、焙烧温度和晶化温度等6个因素对羰基硫催化水解过程中催化剂硫容的影响。结果表明,金属组合、二价金属比和焙烧温度的影响极其显著(p=99%),晶化温度的影响显著(p=95%),合成pH与M2+/M3+对催化剂活性影响不显著(p=90%)。在设定实验条件下,金属组合取Co-Ni-Al、合成pH为9,M2+/M3+为3,二价金属比1,焙烧温度取350℃,晶化温度50℃时制得的催化剂具有最高的催化活性。对最佳制备条件下得到的催化剂进行了重复性实验以及XRD表征,结果表明制备的催化剂的硫容为7.10 g硫/g催化剂,Co3O4可能是其活性中心。     

废环氧树脂/PVC复合材料的性能

将废环氧树脂与聚氯乙烯(PVC)共混,采用模压工艺制备复合材料。通过正交实验,讨论废环氧树脂添加量、硅烷偶联剂KH-550用量、模压时间3个因素对复合材料力学性能的影响大小,得到其优化条件。在正交实验所得优化条件基础之上,研究单因素对复合材料的影响,最终确定实验的最优方案。结果表明:当模压时间10 min,废环氧树脂添加量70%,硅烷偶联剂用量2份时,复合材料的力学性能达到最优,冲击强度为10.49 kJ/m2,拉伸强度为62.24 MPa。     

工业废水污泥的热解及升温速率对热解的影响

利用热重分析法对印染、中药和废水处理厂3种典型工业废水污泥进行了热解动力学实验研究。结果表明,工业污泥是一种高挥发分、低固定碳和低热值的劣质燃料。经过消化处理的污泥灰分含量较高,挥发分含量变小。热解过程中有3个失重速率较高的阶段,以挥发分的析出为主。升温速率对热解的最终失重率有重要影响。升温速率增加,热解更剧烈,但最终失重率的变化趋势与污泥种类有关;为使热解效果更好,不同种类的污泥应选择不同的升温速率。不同种类的污泥具有不同的热解特性,印染污泥挥发分析出阶段有2次热解。中药污泥活化能最小,印染污泥挥发分第2次热解的活化能比第1次大幅增加。     

福建龙岩可持续发展实验区规划探讨及实践

可持续发展实验区总体规划是区域规划的一种特殊类型。通过对可持续发展实验区及其总体规划的理解和认识,文章指出地方可持续发展实验区总体规划的编制思路应当回归到问题指向型的出发点上来。规划编制思路应当紧密结合宏观经济发展环境、社会事业新要求以及全球环境变化压力等背景,从地区人地关系的突出问题入手,制定实验区可持续发展战略,并通过重点项目落实到规划实施中,使可持续发展实验区总体规划体现实验、探索、示范、创新的作用。文章以福建龙岩可持续发展实验区总体规划编制的实践经验为例,对规划编制思路进行探讨。     

Evaluation of surface runoff and road dust as sources of nitrogen using nitrate isotopic composition

Stable nitrogen and oxygen isotope ratios of nitrate (δ¹⁵N-NO₃ and δ¹⁸O-NO₃) have recently been used to identify nitrogen sources in water environments. However, there have been no investigations designed to determine nitrate isotopes in non-point sources in urban areas for evaluating the impact of surface deposits on nitrogen in surface runoff. In this study, we collected rainwater, surface runoff and surface deposits (road dust, roof dust and soil) to evaluate the nitrogen sources in surface runoff using nitrate isotopes. There were no large differences in δ¹⁵N-NO₃ among rainwater (−0.3‰ to 1.5‰), surface runoff (−2.7‰ to 0.4‰), leachates from road dust (−5.8‰ to 6.2‰) and soil (−11.5‰ to 0.6‰). In contrast, the δ¹⁸O-NO₃ in surface runoff (28.5-47.9‰) was lower than that in rainwater (62.7-78.6‰), and higher than that in leachates from road dust (6.1-27.6‰) and soil (−1.1‰ to 6.6‰). δ¹⁸O-NO₃ is a useful indicator for evaluating the NO₃-N sources in surface runoff. Using this indicator, NO₃-N from road dust was estimated to account for more than half of the NO₃-N in surface runoff. This is consistent with a result based on a comparison of their loads per unit surface between rainwater and surface runoff, which also showed that most of the nitrogen in surface runoff was derived from surface deposits.     

Using stable lead isotopes to trace heavy metal contamination sources in sediments of Xiangjiang and Lishui Rivers in China

Lead isotopes and heavy metal concentrations were measured in two sediment cores sampled in estuaries of Xiangjiang and Lishui Rivers in Hunan province, China. The presence of anthropogenic contribution was observed in both sediments, especially in Xiangjiang sediment. In the Xiangjiang sediment, the lower ²⁰⁶Pb/²⁰⁷Pb and higher ²⁰⁸Pb/²⁰⁶Pb ratio, than natural Pb isotope signature (1.198 and 2.075 for ²⁰⁶Pb/²⁰⁷Pb and ²⁰⁸Pb/²⁰⁶Pb, respectively), indicated a significant input of non-indigenous Pb with low ²⁰⁶Pb/²⁰⁷Pb and high ²⁰⁸Pb/²⁰⁶Pb. The corresponding concentrations of heavy metals (As, Cd, Zn, Mn and Pb) were much higher than natural values, suggesting the contaminations of heavy metals from extensive ore-mining activities in the region.     

水培彩叶草抑制藻类繁殖的试验研究

通过人为控制光照、温度和培养液体积栽种水培彩叶草(简称彩叶草),并对彩叶草的抑藻能力进行测定,分析了彩叶草抑藻过程中营养物质浓度变化,并与凤眼莲的抑藻效果进行对比.结果表明,在不同培养条件下,彩叶草均能明显抑制藻类的过度生长;在保持培养液营养物质自然变化的条件下,栽种彩叶草与不栽种彩叶草培养液的营养物质浓度均直线下降,...     

废旧线路板次氯酸盐法浸金的实验研究

研究了酸性条件NaClO-HCl和碱性条件NaClO-NaOH下浸出废旧线路板中的金.通过正交设计优化实验比较发现,NaClO-NaOH碱性体系浸金较有优势,其最佳的浸金条件为NaClO浓度6 mol/L,NaOH浓度8 mol/L,固液比l∶6,反应时间40 min,金的浸出率可达到94.5%.次氯酸盐浸金具有浸金效...