城市生活垃圾的微生物处理技术

城市生活垃圾量的日益增多严重威胁着城市的环境及人们的健康,垃圾处理成为现代社会面临的重要问题之一,因此城市生活垃圾处理技术对于城市的可持续发展起着非常重要的作用。微生物在自然界中种类繁多,在城市生活垃圾生物处理应用中占有重要地位。本文对微生物在城市生活垃圾的卫生填埋技术、生物反应器填埋技术、好氧堆肥技术、发酵降解技术及生物干燥器技术中的应用进行了综述,并对城市生活垃圾的综合处理提出建议,以期为城市生活垃圾的微生物处理技术的应用提供参考。     

用管式光生物反应器培养螺旋藻的研究

微藻大规模培养主要有敞开式大池培养和封闭式光生物反应器培养两种主要方式。管式光生物反应器是封闭式光生物反应器的主要类型之一。与其它类型相比,管式光生物反应器放大较易,成本较低。国外关于管式光生物反应器已有不少研究［１～３］但关于管式光生物反应器产率与光强和光暗比的关系等方面的研究尚未得出明确的结论。国内管式光生物反应器的研究较少［４］,尚未见有关管式光生物反应器中微藻悬浮液流变特性基础参数和产率影响因素的报道。螺旋藻是丝状体蓝藻,螺旋藻蛋白质含量高,其蛋白质所含必需氨基酸丰富,是国内外大规模商业…     

转基因动物乳腺生物反应器的发展概况及人工染色体在其中的应用

转基因动物乳腺生物反应器位点效应的影响是制备转基因动物乳腺生物反应器过程中的主要问题。酵母人工染色体（YAC）和细菌人工染色体（BAC）具有容量大的特性,可以将乳蛋白的整个基因座包括所有调控序列全部装载进去,有可能克服位点效应的影响,是一种理想的载体。YAC和BAC载体转基因技术可能成为避开基因打靶获得高效表达的转基因动物乳腺生物反应器的另一途径.     

生物反应器流场特性研究及其在生物过程优化与放大中的应用研究

生物反应器是实现生物过程的核心设备,其内进行的生物反应过程受不同反应器内流场结构的影响会产生差异显著的结果,这也是导致生物过程放大困难的关键问题之一。为研究这一问题,必须对不同规模反应器内流场结构有充分的认识,必须对反应器内的混合、传质、剪切等影响生物过程的几个关键方面进行深入研究。首先简单介绍了反应器流场研究的实验及数值模拟方法,在此基础上详细论述了流场混合与传质对生物反应过程的影响,流场剪切对丝状菌形态及其生物过程的影响,最后从反应器流场与细胞生理代谢特性整合的角度,介绍了反应器流场与细胞生理之间的相互作用关系,并以三个实例简单介绍了基于Euler-Lagrange模拟框架的整合流场和细胞动力学模型的模拟方法及模拟结果。旨在通过介绍反应器流场研究及其在生物过程优化放大中的应用,提出基于反应器流场特性与细胞动力学响应的生物过程放大研究方法,为更高效、理性地生物过程放大提供一些理论参考。     

微藻培养过程的光特性研究进展

微藻培养过程中光的吸收、衰减以及光暗循环等特性是影响微藻的生长速度及其产量的重要因素。本文分析了微藻的光吸收过程、光在微藻培养液中的衰减特性以及微藻培养过程中的光暗循环特性,重点综述了国内外各类光生物反应器中光特性的研究进展,并对其发展方向进行了展望,为微藻培养光生物反应器的设计提供参考依据。     

微小型生物反应器及其在生物医药领域的应用展望

微小型生物反应器体积微小但在线分析检测和过程控制功能媲美台式装备。其核心支撑技术包括一次性材料及微加工技术、非接触式光学传感器、自动化以及实验设计 (DOE)、数据分析软件与过程控制的整合。由于体积微小、湍流程度和单位能耗较低,微小型反应器内的混合、传质、剪切特性与工业规模设备有一定的区别。现阶段微小型生物反应器主要用于菌株和细胞系筛选和工艺优化,在实现高通量工艺的同时确保了数据的丰度,对缩短研发周期和加速产品上市,尤其是在应对突发性传染性疾病方面有着重要的意义。未来,精准医疗概念的落实也依赖功能柔性化的微小型生物反应器系统。     

臭气生物处理技术

介绍了生物滤池、生物洗涤塔和生物滴滤池等常规生物除臭技术以及真菌生物反应器、复合式反应器、物化-生物组合反应器等臭气控制新技术的特性、发展状况及其应用,阐述了生物反应器内的除臭功能菌的特性以及臭气生物处理技术的应用前景。     

封闭式光生物反应器研究进展

国际上80～90年代,封闭式光生物反应器是微藻生物技术的重要研究热点,也是微藻生物技术产业化的关键技术之一。本文较全面地介绍了用于微藻大规模培养的封闭式光生物反应器研究现状。将封闭式光生物反应器分为柱式、管式、板式和光导纤维反应器等类型。工业放大前景的管式和板式光生物反应器采取了典型个案分析的方法,列表比较了典型反应器的主要技术参数,并对它们的技术发展趋势进行了归纳总结。     

氨基酸制造中的生物催化反应器

<正> 生物催化反应器是什么?它由哪几部分组成?如何制作和设计?生物催化反应器在氨基酸制造中的应用等,这是本文要阐述的主要内容。一、什么是生物催化反应器生物催化反应器简称为生物反应器,它是把生物催化剂(酶)和反应设备合在一起的一种装置,也称生化反应器或称酶反应器。其中固定化生物催化反应器有很大的发     

MBR运行初期对基因工程菌的截留特性研究

在膜-生物反应器(MBR)中实施基因工程菌生物强化时, 运行初期基因工程菌流失是生态风险评价的重要内容。在一体式微滤膜-生物反应器中, 考察了运行初期不同运行条件对基因工程菌流失密度和截留效率的影响, 并对截留特性进行了探讨。结果表明, 膜-生物反应器运行初期, 不同运行条件对基因工程菌的截留效率影响不同：污泥浓度增加, 截留效率提高; 提高膜通量和曝气量, 截留效率降低。基因工程菌接种密度为1.0×1010 CFU/mL时, 不同运行条件下的流失密度为1.0×102 CFU/mL~2.5×102 CFU/mL, 最大截留效率大于8 lg。膜-生物反应器运行初期, 膜组件截留、污泥吸附以及对悬浮细胞迁移阻碍是影响截留效率的主要因素, 一定条件下其截留效率贡献率分别为82.3%、14.9%和2.8%。膜-生物反应器稳定运行过程中形成凝胶层, 可以提高截留效率。一定条件下, 膜组件、污泥和凝胶层对基因工程菌的截留贡献率分别为75.3%、10.7%和14.0%。     

Anaerobic digestion of municipal solid waste and agricultural waste and the effect of co-digestion with dairy cow manure

Anaerobic digestion of dairy cow manure (CM), the organic fraction of municipal solid waste (OFMSW), and cotton gin waste (CGW) was investigated with a two-phase pilot-scale anaerobic digestion (AD) system. The OFMSW and CM were digested as single wastes and as combined wastes. The single waste digestion of CM resulted in 62m(3) methane/ton of CM on dry weight basis. The single waste digestion of OFMSW produced 37m(3) methane/ton of dry waste. Co-digestion of OFMSW and CM resulted in 172m(3) methane/ton of dry waste. Co-digestion of CGW and CM produced 87m(3) methane/ton of dry waste. Comparing the single waste digestions with co-digestion of combined wastes, it was shown that co-digestion resulted in higher methane gas yields. In addition, co-digestion of OFMSW and CM promotes synergistic effects resulting in higher mass conversion and lower weight and volume of digested residual.     

Composting potential of different inoculum sources in the modified SEBAC system treatment of municipal solid wastes

The aim of the work described here was to analyse the biomethanization process for three types of organic fraction of municipal solid waste (OFMSW) using two different inoculum sources in a sequential leach-bed anaerobic reactor under thermophilic (55 degrees C) and dry conditions (20%TS). The OFMSWs studied were: separately collected food waste (SC_OFMSW) from restaurants, synthetic waste (ST_OFMSW) and mechanically selected municipal waste (MS_OFMSW). The inoculum studied were digested mesophilic sludge (SLUDGE) and digested SC_OFMSW. The results show that SLUDGE gave the best performance and this was therefore selected for the rest of the experiments. Three assays were performed to analyse the biomethanization processes of three types of organic waste. The results suggest that all three wastes give rise to an acclimation stage with acidogenic/acetogenic activity between days 5 and 20-30 and a stabilization phase associated with methanogenic activity. In conclusion, a mixture of OFMSW (regardless of its origin) and SWINE arranged in layers in the reactor, as well as SLUDGE used with an inoculum source, enhanced the fast start up phase of a modified sequential leach-bed system under dry thermophilic conditions.     

Suitability of aquaculture effluent solids mixed with cardboard as a feedstock for vermicomposting

Recirculating aquaculture systems are highly intensive culture systems that actively filter and reuse water, thus minimizing water requirements and creating relatively small volumes of concentrated waste (compared to flow-through aquaculture systems). Vermicomposting, which uses earthworms to stabilize and transform organic wastes into valuable end-products, has been proposed as an alternative treatment technology for high-moisture-content organic wastes from agricultural, industrial and municipal sources. This study was conducted to determine if the effluent solids from a large recirculating aquaculture facility (Blue Ridge Aquaculture, Martinsville, Virginia) were suitable for vermicomposting using the earthworm Eisenia fetida. In two separate experiments, worms were fed mixtures of solids removed from aquaculture effluent (sludge) and shredded. Mixtures containing 0%, 5%, 10%, 15%, 20%, 25%, and 50% aquaculture sludge (dry weight basis) were fed to the worms over a 12-week period and their growth (biomass) was measured. Worm mortality, which occurred only in the first experiment, was not influenced by feedstock sludge concentration. In both experiments worm growth rates tended to increase with increasing sludge concentration, with the highest growth rate occurring with feedstocks containing 50% aquaculture sludge. Effluent solids from recirculating aquaculture systems mixed with shredded cardboard appear to be suitable feedstocks for vermicomposting.     

Thermophilic anaerobic digestion of source-sorted organic fraction of municipal solid waste

The influence of different organic fraction of municipal solid wastes during anaerobic thermophilic (55 degrees C) treatment of organic matter was studied in this work: food waste (FW), organic fraction of municipal solid waste (OFMSW) and shredded OFMSW (SH_OFMSW). All digester operated at dry conditions (20% total solids content) and were inoculated with 30% (in volume) of mesophilic digested sludge. Experimental results showed important different behaviours patterns in these wastes related with the organic matter biodegradation and biogas and methane production. The FW reactor showed the smallest waste biodegradation (32.4% VS removal) with high methane production (0.18 LCH4/gVS); in contrast the SH_OFMSW showed higher waste biodegradation (73.7% VS removal) with small methane production (0.05 LCH4/g VS). Finally, OFMSW showed the highest VS removal (79.5%) and the methane yield reached 0.08 LCH4/g VS. Therefore, the nature of organic substrate has an important influence on the biodegradation process and methane yield. Pre-treatment of waste is not necessary for OFMSW.     

Bioaerosols from municipal and animal wastes: background and contemporary issues

Global population increases, coupled with intensive animal and livestock production practices, have resulted in the generation, accumulation, and disposal of large amounts of wastes around the world. Aerosolization of microbial pathogens, endotoxins, odors, and dust particles is an inevitable consequence of the generation and handling of waste material. Bioaerosols can be a source of microbial pathogens, endotoxins, and other allergens. Given the close proximity of population centers to concentrated animal-rearing operations and municipal treatment facilities in many parts of the world, there is concern regarding the occupational and public health impacts associated with the exposure to bioaerosols from municipal and animal wastes. Major advances have been made in our understanding of bioaerosol characteristics, identifying the hazards, and identifying possible human and animal health links with aerosolized pathogens and allergens. However, significant knowledge and technology gaps still exist. These include a lack of clear understanding of the fate and transport of bioaerosols, especially within the open environment, an inability to accurately predict the health risks associated with bioaerosolized pathogens, and a lack of standardized bioaerosol sampling protocols, and efficient samplers. This review synthesizes the information related to bioaerosols and addresses the contemporary issues associated with bioaerosols from municipal and animal wastes, with a focus on pathogens.     

Estimation of heats of combustion of biomass from elemental analysis using available electron concepts

The method of Thornton and Dulong's formula for estimating heats of combustion are compared in this work. Heats of combustion predicted by Thornton's method for renewable resources such as wood, straw, and municipal solid wastes are considerably closer to experimentally measured values compared to values predicted by Dulong's formula. Thornton's method states that the heat of combustion is directly proportional to the quantity of oxygen consumed in the combustion process. A method which utilizes the weight fraction carbon on a dry basis and the reluctance degree to predict the heat of combustion of renewable resources is presented.     

Impact of pretreatment on solid state anaerobic digestion of yard waste for biogas production

Solid state anaerobic digestion, as a safe and environment-friendly technology to dispose municipal solid wastes, can produce methane and reduce the volume of wastes. In order to raise the digestion efficiency, this study investigated the pretreatment of yard waste by thermal or chemical method to break down the complex lignocellulosic structure. The composition and structure of pretreated yard waste were analyzed and characterized. The results showed that the pretreatment decreased the content of cellulose and hemicelluloses in yard waste and in turn improved the hydrolysis and methanogenic processes. The thermal pretreatment sample (P1) had the highest methane yield, by increasing 88 % in comparison with digesting the raw material. The maximum biogas production reached 253 mL/g volatile solids (VS). The largest substrate mass reduction was obtained by the alkaline pretreatment (P5). The VS of the alkaline-treated sample decreased about 60 % in comparison with the raw material.     

Key composition optimization of meat processed protein source by vacuum freeze-drying technology

Vacuum freeze-drying technology is a high technology content, a wide range of knowledge of technology in the field of drying technology is involved, it is also a method of the most complex drying equipment, the largest energy consumption, the highest cost of drying method, but due to the particularity of its dry goods: the freeze-drying food has the advantages of complex water performance is good, cooler and luster of freezing and drying food to maintain good products, less nutrient loss, light weight, easy to carry transportation, easy to long-term preservation, and on the quality is far superior to the obvious advantages of other dried food, making it become the forefront of drying technology research and development. The freeze-drying process of Chinese style ham and western Germany fruit tree tenderloin is studied in this paper, their eutectic point, melting point and collapse temperature, freeze-drying curve and its heat and mass transfer characteristics are got, then the precool temperature and the highest limiting temperature of sublimation interface are determined. The effect of system pressure on freeze-dried rate in freeze-drying process is discussed, and the method of regulating pressure circularly is determined.     

Potential of fruit and vegetable wastes as novel biosorbents: summarizing the recent studies

Fruit and vegetable wastes produced in astronomical quantities from food processing and agriculture industries often cause nuisance in municipal landfills owing to their high biodegradability. Biosorption by these waste-based adsorbents can be used as a cost effective and efficient technique for the removal of toxic heavy metals and dyes from wastewater. Recently, many papers claiming the feasible use of these biosorbents for water decontamination, treatment of industrial and agricultural wastewater and valuable metal recovery have been published. The organic waste-based adsorbents, characterized by good uptake capacity and rapid kinetics are expected to be economically and ecologically viable. This paper presents a judicious and pragmatic review depicting the key advances in implications of the fruit and vegetable wastes in pollution mitigation, the underlying mechanisms, major challenges and the future implementations. This compilation is expected to provide an impetus to the bioremediation research and promote green technology.     

Drying of Tribenuron,a Thermosensitive Biochemical

The extension of microwave use in the biochemical industry was explored by drying tribenuron, a thermosensitive biochemical, in a microwave oven and in a thermal vacuum oven. Tribenuron wet cakes, containing a mixture of solvents, methanol and water, were heated at 40 °C in both ovens. Nitrogen purge was used to prevent the decomposition of tribenuron from prolonged heating. Microwave heating dried tribenuron in twenty minutes while the vacuum oven heating required eighteen hours to dry the wet cakes. In addition, the tribenuron quality was maintained under microwave drying, but deteriorated in the thermal vacuum oven. Therefore, microwave technology is more effective in drying tribenuron than conventional vacuum ovens. The results of this study are important for the use of microwave drying on a large scale in biochemical companies.