河道淤泥和堆肥蛭石混合发酵制备基质及其育苗效果

农村河道清淤产生的淤泥,体量大、有机物浓度高,处置不当会造成二次污染。现代农业的工厂化育苗需求大量的营养土,就地取土导致耕地退化。该研究利用功能微生物发酵淤泥制备育苗基质,研究不同菌株发酵基质的物理和生物学性状,基质培育西瓜苗的生长、生理参数和抗逆性能。结果表明:微生物处理均能够提升淤泥基质物理和生物学性能,同时能够提升育苗质量。其中Trichoderma harzianum T83(T83)、Bacillus amyloliquefaciens IAE(BIAE)菌株发酵基质性能最好。相较于对照处理基质的最大持水量、总孔隙度、毛管孔隙度、通气孔隙度,T83处理分别增加了64.25%、52.65%、45.05%、56.11%;BIAE处理分别增加了101.17%、45.43%、61.43%、38.14%。相较于对照处理西瓜苗的株高、鲜质量、干质量、叶绿素含量、根系活力、根际真菌、细菌数量,T83处理分别增加了66.85%、52.07%、72.16%、43.13%、54.93%、110.62倍、1.63倍;BIAE处理分别增加了80.40%、57.34%、82.37%、54.88%、46.40%、67.26%、2.60倍、2.94倍。T83和BIAE处理西瓜苗叶片过氧化氢酶和超氧化物歧化酶酶活显著增加,根系丙二醛含量显著降低。真菌菌株T. harzianum T83和细菌菌株B. amyloliquefaciens IAE发酵淤泥,能够显著提升其农用品质,为淤泥高附加值化农用提供一条可行的途径。     

Potato absorption and phytoavailability of Cd,Ni, Cu,Zn and Pb in sierozem soils amended with municipal sludge compost

Effects of sludge utilization on the mobility and phytoavailability of heavy metals in soil-plant systems have attracted broad attention in recent years. In this study, we analyzed the effects of municipal sludge compost(MSC) on the solubility and plant uptake of Cd, Ni, Cu, Zn and Pb in a soil-potato system to explore the mobility, potato plant uptake and enrichment of these five heavy metals in sierozem soils amended with MSC through a potato cultivation trial in Lanzhou University of China in 2014. Ridge regression analysis was conducted to investigate the phytoavailability of heavy metals in amended soils. Furthermore, CaCl_2, CH_3 COONH_4, CH_3COOH, diethylene triamine pentacetic acid(DTPA) and ethylene diamine tetraacetic acid(EDTA) were used to extract the labile fraction of heavy metals from the amended soils. The results show that the MSC could not only improve the fertility but also increase the dissolved organic carbon(DOC) content of sierozem soils. The total concentrations and labile fraction proportions of heavy metals increase with increasing MSC percentage in sierozem soils. In amended soils, Cd has the highest solubility and mobility while Ni has the lowest solubility and mobility among the five heavy metals. The MSC increases the concentrations of heavy metals in the root, stem, peel and tuber of the potato plant, with the concentrations being much higher in the stem and root than in the peel and tuber. Among the five heavy metals, the bioconcentration factor value of Cd is the highest, while that of Ni is the lowest. The complexing agent(DTPA and EDTA) extractable fractions of heavy metals are the highest in terms of phytoavailability. Soil properties(including organic matter, p H and DOC) have important impacts on the phytoavailability of heavy metals. Our results suggest that in soil-potato systems, although the MSC may improve soil fertility, it can also increase the risk of soils exposed to heavy metals.     

城市污泥施用对沙地油菜的影响及效果评价

针对京郊沙质土壤贫瘠,植被生长缺乏营养物质等问题,采用盆栽实验研究了污泥添加量对油菜长势及沙质土壤理化性质的影响,测定了油菜长势、营养成分的含量以及重金属的有效浓度,并采用层次分析法构建了污泥改良沙质土壤方案选取分析模型,确立了最佳污泥添加量。结果表明,适量的污泥可有效改善沙质土壤中有机质、全氮和有效磷的含量;且有利于油菜的生长,油菜的发芽率、株高和生物量的增加率分别达到10%、131.55%和58.84%。重金属风险评价结果表明,当污泥浓度低于20%时,土壤处于清洁状态。分析模型评价结果表明3%为污泥的最佳添加量,为今后污泥的资源化利用以及京郊沙质土壤的改良提供了一定的理论依据。     

纳米酶免疫层析试纸条法检测玉米褪绿斑驳病毒

【目的】建立纳米酶免疫层析试纸条(Nanozyme Immuno-chromatographic Strip Assay, NISA)检测玉米褪绿斑驳病毒方法。【方法】采用双抗夹心法,将纳米酶标记的鼠抗体IgG与McmV结合后,再与硝酸纤维素膜质控线上的鼠抗体结合,二氨基联苯胺(Diaminobenzidine, DAB)滴加显色。【结果】采用研制的NISA和反转录PCR法(RT-PCR)对玉米褪绿斑驳病毒梯度稀释的研磨液进行检测,灵敏度分别为10^-7和10^-5;用其他4种病毒作对照进行特异性实验,无交叉反应;用该试纸条对供试样品进行检测,并以RT-PCR方法及基因测序方法对检测结果进行验证,三者检测结果一致。【结论】该试纸条检测McmV的灵敏度高、特异性强,可用于科研、农业生产单位和口岸机构对McmV的检测。     

Dynamics of Integration between Chinese and International Waste Paper Markets

ABSTRACT

China is the largest importer of waste paper in the world and is highly dependent on the international market. Thus, the relationship between Chinese and international waste paper markets affects the supply of fiber materials in China’s paper industry. This study examined the dynamic relationship between the two markets and the impact of newly implemented policies on both markets. We used unit root tests, cointegration test, vector error correction model (VECM) and frequency-domain Granger causality test to investigate the integration between Chinese and international waste paper markets and identify which of the two markets is the price leader. The results revealed that the two markets were integrated after controlling for structural breaks, and the Chinese market acted as the price leader. Since the supply of waste paper and wood pulp is insufficient in China to meet the fiber demand of the paper industry, waste paper import restrictions have significantly affected the supply of fiber materials in China’s paper industry. Therefore, the Chinese government should fully consider the benefit of market integration and make full use of international waste paper resources to satisfy the large domestic demand for paper products.     

不同裂解温度的污泥生物质炭理化特性分析

研究裂解温度对污泥生物质炭基础理化性质的影响,为安全、合理、高效处置污泥提供理论依据。将干燥污泥分别在200、300、500、700℃下进行热裂解处理(SBC200、SBC300、SBC500、SBC700),获得污泥生物质炭,测定其基础理化特性。结果表明：不同温度制备的污泥生物质炭表面颗粒结构完好,孔径范围均集中在10~50 μm,其中低温生物质炭SBC200表面较光滑,最可几孔径和中值孔径最大,分别为20.1 μm和14.8 μm,高温生物质炭SBC700表面较粗糙,比表面积最大,为5.98 m²/g。随裂解温度的提高,污泥生物质炭的产率、含水量、电导率、挥发分、阳离子交换量显著下降,全碳、氧、全氮、氢含量、有效磷和铵态氮均逐渐降低,pH和灰分含量显著增加。将污泥制备成生物质炭,是安全处置污泥的有效途径,低温制得的污泥生物质炭具有更大的提高土壤肥力的潜力,而高温制得的生物质炭在改良土壤酸性的应用上具有更大的潜力。     

废纸回收材料化利用研究进展

简述了国内外废纸回收利用现状,重点阐述了废纸在建筑填料、制备高附加值纤维衍生物以及复合材料等方面的利用研究现状,并针对废纸材料利用过程中存在的高吸水率和弱结合界面等问题提出了相应的解决方法和研究方向。     

饱和度及干密度对弱膨胀土土水特征曲线影响

采用滤纸法测量不同干密度下试样的总吸力与基质吸力,并绘制相应的土水特征曲线,分析饱和度与干密度对土水特征曲线的影响.实验结果表明:在饱和度一定时,总吸力与基质吸力均随干密度的增大而增大;随饱和度增大,不同干密度的总吸力差值和基质吸力差值逐渐减小;另外,试样的排水速率随饱和度的增大而减小,且干密度越大,排水速率越慢.在较低含水率时,试样的总吸力和基质吸力随干密度的增大而增大,随含水率的增大,干密度对总吸力和基质吸力的影响逐渐弱化.     

发酵污泥不同施用方式对土壤温度和棉花苗期生理特性的影响

[目的]研究城市发酵污泥在棉花上的最佳施用方式,降低棉花生产成本。[方法]采用盆栽试验方法,探讨不施用发酵污泥(CK)、污泥覆盖土壤表面(处理(1))、污泥与土壤混合(处理(2))、混合+覆盖(处理(3))4种方式对棉苗、根系生长的影响。[结果]污泥的不同处理对棉花苗期根际土壤温度增温效果明显,以10 cm处土层最明显,处理(1)、(2)、(3)地温平均较对照CK高1.2、2.9、1.5℃;显著促进棉花苗的生长,棉花出苗率、健苗率、株高、叶面积、叶片数与CK相比极显著增加;对棉花苗根有诱导和促进生长作用,根长、根数量、根粗、根体积显著高于CK。[结论]发酵污泥3种不同施用方式都能够促进棉花苗生长,改善叶片和根的各项生理指标。整体来看,处理(2)综合优势好,是发酵污泥较有效的施用方式。     

苎麻骨纤维餐具降解性能研究

为了了解苎麻骨纤维餐具的降解规律，为其规模化生产提供依据，采用活性污泥法对其生物降解性能进行了研究。以生物降解率为考察指标，分析活性污泥对于聚丙烯（PP）、滤纸、苎麻骨纤维餐具、纸浆模塑餐具和塑料淀粉餐具的降解能力。结果表明，在降解期间（28天），滤纸降解速度最快，纸浆模塑餐具次之，苎麻骨纤维餐具降解程度低于纸制，生物降解率达到60．59％。而聚丙烯餐具和塑料淀粉餐具基本不降解。增加降解物的表面积和提高活性污泥与降解物的比值，有利于苎麻骨纤维餐具的降解。