The removal of heavy metals in anaerobic upflow sludge blanket reactors

The continuous removal of heavy metals by the biological solids in an anaerobic reactor has been examined. The metals used were chromium (III), zinc and lead. Both competitive and non-competitive removal was studied. The results were evaluated in terms of adsorption isotherms and were compared with earlier batch studies. This suggested that the sludge acted as a cation-exchange material, with chromium having a much lower binding intensity than lead and zinc. The data also suggest that the nature of the sludge surface is of considerable significance in determining the capacity and intensity of binding. The effect of the metals on biogas formation was also examined. This showed that inhibition of the gas formation was a function of the metal concentration and that the relative toxicities appeared to be zinc > lead > chromium.     

The Main Technology of Solid Waste Treatment

This essay illustrated the three main solid waste trealment,biogas technology,landfill and incineration.Limitations and improvements Of each technology were discussed.     

氧化应激引起的遗传变化和DNA甲基化改变在肿瘤发生中的作用

氧化应激不但可导致基因遗传变化,还可诱发表观遗传变化。氧化应激引起的遗传变化主要是活性氧（ROS）攻击DNA,造成DNA链断裂、碱基修饰、DNA—DNA交联和DNA．蛋白质交联等多种形式的DNA损伤,这些损伤在肿瘤发生起始阶段发挥重要作用。氧化应激引起的表观遗传变化中,一个重要的机制是DNA甲基化水平改变,主要表现在高甲基化引起基因转录抑制（如抑癌基因）和低甲基化诱导基因转录激活（如癌基因）,DNA甲基化水平变化与肿瘤发生息息相关。本工作介绍了ROS诱导的氧化应激引起的遗传改变和DNA甲基化水平变化在肿瘤发生中的作用,并展望了肿瘤治疗的发展趋势。     

农村沼气转型升级机遇与对策

我国农村沼气经过多年的发展,已经具备了一定的产业基础和发展优势,成为促进现代农业发展的重要动力和实现农村节能减排的有效载体。结合当前农村经济社会的发展需求,分析现阶段农村沼气产业发展中矛盾,进一步研究、探索沼气转型与升级对策,促进沼气可持续发展。     

粒径对餐厨沼渣热解制备生物炭中磷和重金属的影响

以3种粒径餐厨沼渣为原料,在600℃下热解制备生物炭,研究粒径对沼渣（BR）及生物炭（BRC）中磷和重金属的影响,并采用TCLP浸出毒性和重金属潜在生态风险评估对其安全性进行系统研究。结果表明：BR及BRC中的磷主要以酸溶态磷（HCl-P）为主,残渣态磷（Res-P）次之,其余磷形态含量较低,总磷含量均呈现出随粒径增大而降低的趋势。热解促进H₂O-P、NaHCO₃-P和NaOH-P向HCl-P和Res-P转化。随着粒径的增大,BR中Cu、Zn总量增加,Cr减少,BRC中的Cr、As总量增加,Zn、Pb减少。并且BR中Cr、Zn、Pb和As中可氧化态和残渣态F3+F4随粒径增大而减少;BRC中Cr、Pb、As中F3+F4随粒径增大而减少,而Cu、Zn、Cd与之相反。TCLP浸出毒性和重金属潜在生态风险评估结果表明BR及BRC中重金属均属于低风险水平。     

郭家堡乡沼气建设情况及存在问题研究

根据农村沼气建设的规划和补贴政策,从建池开始,做到建管结合,提高建池的合格率,保证覆盖率,加强技术管理和后续服务技术培训和服务质量,提出措施和建议。     

真空变压吸附沼气净化过程的仿真研究

真空变压吸附(VPSA)是一种气体分离技术,该技术运用在沼气净化过程还存在较多的问题,针对该过程吸附塔出口浓度出现的浓度峰问题,运用线性推动力模型(LDF)与Langmuir等温方程对其建立了数学模型,模拟分析了缓冲罐中杂质浓度对吸附步骤出口浓度的影响。结果表明:相同吸附时间下,随着吸附压的降低,二均降结束时会有更多的杂质进入缓冲罐,而缓冲罐中的杂质又会通过一均升步骤进入吸附塔,最终使得吸附步骤出口浓度曲线出现波峰,从而影响了吸附塔出口CH₄含量。通过模型的分析,吸附时间随着吸附压不断降低而缩短,可以有效控制杂质进入缓冲罐,从而使吸附塔出口CH₄含量提高。     

一种新型反应器——生物气射流循环厌氧流化床的启动与运行特性

A novel anaerobic reactor, jet biogas inter-loop anaerobic fluidized bed （JBILAFB）, was designed and constructed. The start-up and performance of the reactor was investigated in the Process. of .artificial glucose wastewater treatment. With the wastewater recycle ratio of 2.5 ： 1, the recycled wastewater with biogas could mix sludge and wastewater in the JBILAFB reactor completely. The start-up of the JBILAFB reactor could be completed in less than 70 d through maintenance of hydraulic retention time （HR~I＂） and stepwise increase of feed total organic carbon （TOC） concentration. After the start-up, with the volumetric TOC loadings of 14.3 kg·m ^-3·d^-1, the TOC removal ratio, the effluent pH, and the volatile fatty acids （VFA）/alkalinity of the JBILAFB reactor were more than 80%, close to 7.0 and less than 0.4, respectively. Moreover, CH4 was produced at more than 70% of the theoretical value, The reactor exhibited high stability under the condition of high volumetric TOC loading. Sludge granules in the JBILAFB reactor were developed during the start-up and their sizes were enlarged with the stepwise increase of volumetric TOC loadings from 0.8 kg.m^-3.d ^-1 to 14.3 kg.m^-3.d^-1. Granules, an offwhite color and a similar spherical shape, were mainly comprised of global-like bacteria. These had good methanogenic activity and settleability, which were formed probably through adhesion of the bacteria. Some inorganic metal compounds such as Fe, Ca, Mg, Al, etc. were advantageous to the formation of the granules.     

沼气发酵过程研究进展

综述了沼气发酵菌群、工艺控制和处理系统方面的研究进展,指出对发酵机理缺乏了解是导致过程不稳和效率不高的主要原因,提出将来的研究重点应通过元基因组手段解析菌群相互作用和代谢网络,建立基于反应器操作、VFAs代谢、活性菌群变化和功能基因表达的多尺度过程控制手段,以及发展原料预处理、科学配伍和两相联产氢气甲烷等工艺来提高系统效率.     

沼气发电机组综述

文章主要介绍新型热力发电机组——沼气发电机组,并且对沼气发电机组的使用和发展情况进行了评述。沼气具有来源广泛,可使废物充分利用,经济,易燃烧,效率高,排放清洁等特点。沼气发电机组主要使用沼气发动机为固定动力源。深入研究沼气的充分利用和沼气发动机的工作原理是有着积极的意义。