改性竹炭固定化威尼斯不动杆菌吸附协同降解柴油废水的机理及动力学分析

利用改性竹炭作为载体来固定化威尼斯不动杆菌(Acinetobacter venetianus),用于去除柴油.结果显示,培养96 h后,固定化菌对柴油的去除率为86.35%,要高于游离菌(80.50%).为了探究固定化菌去除柴油的机理,采用动力学拟合实验数据,发现固定化菌去除(吸附-降解)柴油中总石油烃(TPHs)的过程符合伪二级动力学,表明TPHs是先吸附在改性竹炭上,然后被目标菌降解.为了进一步证实,利用扫描电镜(SEM)观察到Acinetobacter venetianus很好地固定在载体材料上.傅里叶红外光谱(FTIR)结果表明,经固定化菌处理后,柴油水溶液的谱图在3437.2、2924.4、1407.8 cm-1处出现新的吸收峰,可能为烷烃降解的酯类及羧酸类物质.GC-MS分析表明,相比游离菌,固定化菌对柴油的去除更为彻底.因此,改性竹炭不仅可以作为良好的固定化载体,同时因其对TPHs良好的吸附性能从而提高了去除效率,为油类污染中TPHs的生物材料修复提供了一个新的视角.     

培养基种类和培养条件对白腐真菌生长和产酶特性的影响

以白腐真菌(Phanerochaete chrysosporium)为研究对象,比较了该菌种在人工合成培养基和天然培养基中的生长和产酶特性,考察了竹子浸出液,pH,载体和抗生素等对白腐真菌在天然培养基中生长和产酶特性的影响.结果表明,天然培养基中白腐真菌的生物量、菌丝小球直径和木质素过氧化物酶(LiP)活性均大于人工培养基.以天然培养基为基础培养基,加入竹子浸出液可以促进白腐真菌的生长和提高木质素过氧化物酶活性;较低pH(4.5)条件下菌丝小球直径较小;载体的加入使得菌体以附着形式生长;抗生素两性霉素B对白腐真菌的生长和产酶的影响存在阈值,当ρ(两性霉素B)超过50　mg/L时,白腐真菌的生长和产酶受到明显的抑制.      

响应面法优化烧烤竹炭对水中磷的吸附条件

采用响应面法优化烧烤竹炭(BBC)对水中磷的吸附条件。用Box-Behnken Design实验设计考察初始磷质量浓度、BBC粒径、BBC加人量和初始溶液pH等因素对磷去除率的影响。实验结果表明:各因素对磷去除率影响的大小顺序依次为初始溶液pHBBC粒径初始磷质量浓度BBC加入量;BBC吸附水中磷的最佳反应条件为初始磷质量浓度26.81 mg/L,BBC粒径0.15 mm,BBC加入量10.6 g/L,初始溶液pH 4.42;在最佳反应条件下,BBC对磷的去除率达90.04%。     

Bond behaviour of bamboo splints in cement-stabilised rammed earth blocks

This paper represents an effort to study the bond characteristics of plain and noded bamboo splints embedded in cement-stabilised rammed earth (CSRE) blocks. A series of CSRE pullout test specimens and two species of bamboo, namely Melocanna Baccifera and Bambusa Balcooa having an average tensile strength of 384 and 310 MPa, respectively, were fabricated using 4–10% Portland cement. These bamboo species are commonly available and widely used for construction in the north-eastern part of India. Besides considering the effects of soil strength, cement content, splint size and type on bond force and slip, the effect of embedded area was also briefly considered as part of the test programme. The test result showed that pullout bond resistance is correlated to rammed earth compressive strength, splint size and type, and embedded area.     

竹子生物质废弃物前处理技术比较研究

为开发高效、低成本的预处理技术,促进竹子生物质及其废弃物资源的能源化利用,采用3种不同纤维素预处理方法分别对竹子生物质废弃物——笋壳和竹叶(茎)进行比较研究,同时与玉米秸秆相比较.结果表明,在稀H2SO4–酶解工艺、浓H3PO4–酶解工艺和NaOH–酶解工艺条件下,几种样品水解液中分别存在3、4和5种糖类组分.在稀H2SO4–酶解工艺中,木糖为主要成分,其次为葡萄糖;在浓H3PO4–酶解工艺中,葡萄糖为主要成分,其次为木糖;而在NaOH–酶解工艺,葡萄糖和木糖含量基本相当.同时对样品处理前后的表面结构变化分析表明,不同处理工艺均改变了竹叶(茎)、笋壳和秸秆等样品的表面结构,其结构更为松散,从而有利于纤维素的酶解.     

不同用量竹炭对污泥堆肥过程温室气体排放的影响

采用城市污泥为堆肥基质,设置4个堆肥处理,分别为添加2.5%竹炭(S1,占污泥的质量分数)、添加5%竹炭(S2)、添加10%竹炭(S3)和未添加竹碳(CK),研究城市污泥堆肥过程中温室气体的动态变化特征及添加不同用量竹炭的影响.结果表明,CH_4排放主要在升温期和高温前期,占排放总量的99.01%~99.81%.当竹炭添加量低于5%时,CH_4排放量随添加量的增加而减少;竹炭添加量高于5%时,其排放量又明显增加.CO_2排放集中在升温期和高温期,占排放总量的75.65%~86.58%;添加竹炭可减少3.37%~13.48%的CO_2排放,但处理间不存在显著差异(P0.05).N_2O排放集中在升温期和降温腐熟期,添加竹炭能减少16.37%~41.52%的N_2O排放,竹炭添加量越多,减排效果越好(P0.05).S1、S2和S3处理CO_2排放当量(以干污泥计)分别为37.57、35.10和35.44 kg·t~(-1),比CK处理减少了14.81%~20.41%.添加竹炭能降低污泥堆肥温室气体排放,其中,以S2处理的减排效果较为显著.     

脱氮副球菌W12在游离生长与附着生长条件下对吡啶去除作用的研究

分离到1株吡啶降解菌——脱氮副球菌(Paracoccus denitrificans W12),将其附着生长于颗粒活性竹炭(ABC)制备成生物活性竹炭(BABC),分别以游离菌和固着菌开展对水中吡啶的去除实验.结果表明,0.31g·L-1游离态W12菌可在26.5～48.9h内将48.70～1399mg·L-1的吡啶完全降解;附着于ABC的W12菌不仅保持其降解能力,而且BABC通过吸附与降解的协同作用更高效地去除吡啶,当温度为35℃,BABC投加量为10.0g·L-1时,692.2mg·L-1的吡啶在前3.6h主要通过吸附作用降低52%,其后主要通过生物降解作用至23.7h被基本去除,随着BABC投加量和处理批次的增加,吡啶去除效率显著提高.研究进一步从微观结构上对BABC去除水中吡啶的协同作用机制进行了探讨.     

笋用小径竹林土壤有机农药污染研究

对笋用小径竹林土壤有机农药残留量主成分的分析表明,前3种主成分的贡献率分别为43.927%,26.429%和11.720%,土壤有机农药污染主要为有机氯和拟除虫菊类农药.经主成分综合因子分析,笋用小径竹林土壤有机农药污染可分为三类,即集约经营竹林＞中等集约经营竹林＞粗放经营竹林.     

开发竹醋液--提高安徽省竹资源利用率

从安徽省竹资源现状、竹醋液的生产概况、应用领域、经济价值、政策扶持等方面分析了竹醋液开发的可行性,目的是提高安徽省竹资源的利用率,促进安徽省经济的可持续发展.     

The potential of bamboo as an interceptor and converter of solar energy into essential goods and services: focus on Ethiopia

SUMMARY

The sun is the ultimate energy source of the Earth. This energy is a resource if utilised, a menace if not. Plants collect and transform radiant energy to chemical energy through photosynthesis. Part of the converted energy is used for their maintenance, while the remainder is stored as biomass. The living biomass plays a vital role in ecological processes and relationships, and provides essential services: soil and water conservation, a buffer against the adverse effects of rain, wind and sun, aesthetics, recreation, and environmental cleaning. Harvested biomass provides safe energy and materials for production of valuable products through industrial processes and household-based technologies. In the absence of vegetation, solar radiation dries soil moisture and disrupts natural processes essential for healthy ecosystem sustenance. Light-use efficiency of plants is positively correlated with rate of growth and bamboos are among the fastest growing perennial plants. This paper is not a thorough review of radiation or bamboo. The following issues are highlighted: (1) The flow of sunlight to the Earth and its usefulness as a resource if used properly and its tendency to become a nuisance if not. (2) The virtues of bamboos as light interceptors and providers of goods and services, better than many tree species. (3) The endowment of Ethiopia with large natural bamboo resources, the availability of denuded land for expansion, and the urgency for proper management, expansion and utilisation for faster socio-economic development and environmental improvement.