An overview on biogas generation from anaerobic digestion of food waste

Food waste is an inevitable type of waste in every city, and its treatment technology evolves with time. Due to the high organic content and high biodegradability of food waste, anaerobic digestion becomes a commonly accepted treatment method to deal with it. This review article summarizes key factors for anaerobic digestion and provides useful information for successful anaerobic digestions. Reasonable temperature and pH are essential for a successful and productive anaerobic digestion process. A good inoculum to substrate ratio triggers a profitable food waste digestion. Good mixing and small particle sizes are important factors too. In addition, the pros and cons of different reactors to food waste digestion are highlighted. Moreover, co-digestion of food waste with animal manures, sewage sludge, and green waste were introduced.     

利用水葫芦治理水体富营养化与生产沼气的环境经济学分析

资源化、无害化利用水葫芦是治理其泛滥的有效途径。利用水葫芦去除水体中的营养物并利用其生物质生产沼气在技术上具有可行性,但是其环境经济效益尚不明确。以滇池为例,针对富营养化水体的水葫芦控制进行了成本收益分析。与将水葫芦打捞后填埋处理相比,将所打捞的水葫芦用于生产沼气具有经济可行性和能量效率。与现行的填埋处理法相比,实施沼气项目不但同样能控制水葫芦泛滥,而且能生产能源。此外,填埋水葫芦会释放甲烷这一环境问题值得重视,利用水葫芦生产沼气可以减少温室气体的排放,但减排的价值取决于沼气厂的生产规模。由于将水葫芦填埋和用于生产沼气都能去除水体中的营养物,只有当沼气厂的水葫芦处理量大于当前的填埋量时,沼气项目才具有额外的水质改良价值。在中国关于水污染控制、可再生能源发展和节能减排等政策的背景下,利用水葫芦生产沼气是一种潜在的政策响应     

Reducing carbon emissions through improved household energy efficiency in the UK

A number of schemes to increase household energy efficiency have operated in the UK over the last 5–10 years. This paper evaluates their effectiveness in terms of reducing household energy use, carbon emissions and fuel poverty. It then draws on the quantitative results of these schemes, and published plans for their continuation, to model an extended and expanded Household Energy Efficiency Scenario to 2020, using an integrated economy–energy–environment model of the UK. The results suggest that while such schemes can play a significant role in reducing carbon emissions from households, much more ambitious schemes than those currently implemented will be necessary to offset the underlying growth in these emissions. Finally, the results are compared with the UK government's own estimates, in its Climate Change Programme, of carbon emission reductions from such schemes to 2010. The paper concludes that the government's estimates are somewhat optimistic, and that it will need substantial new policy measures beyond those already announced if its carbon reduction targets in this area are to be met. Copyright © 2002 John Wiley & Sons, Ltd.     

机械淋滤-厌氧生物组合工艺处理有机生活垃圾中试研究

采用机械淋滤/厌氧生物组合工艺,充分发挥机械淋滤反应器的水解酸化功能和厌氧生物反应器的产甲烷功能,对有机生活垃圾进行了中试规模处理。厌氧生物反应器经过接种,15 d驯化完成。厌氧反应器出水回流淋洗水量对机械淋滤反应器运行特征有较大影响,当回流淋洗水量为3.0 m3/d时,淋滤液COD、VFA第8天时浓度分别为41 000 kg/L和2 000 kg/L。对机械淋滤反应器/厌氧反应器组合工艺进行了多批次实验,每吨有机生活垃圾平均产生沼气87.2 m3,甲烷含量稳定在75%,平均产沼系数为0.46 m3/kg COD,厌氧生物反应器出水COD平均值为560 mg/L,在对有机生活垃圾处理的同时实现有机生活垃圾资源化利用。     

农村联户沼气工程可行性研究及经验——以浙江省江山市淤头镇为例

以浙江省江山市淤头镇联户沼气工程为例,从经济、技术及社会可行性三方面进行具体分析,指出联户沼气相比户用沼气具有规模经济效益显著、资金支持渠道多、管理便利、农户满意度高、技术和市场创新空间大等突出优势,可为联户沼气工程推广提供经验借鉴。     

米东区居民生活垃圾分类收集及处理调查分析

随着城市的快速发展,城市生活垃圾对环境的危害越来越大,已经成为影响城市居住环境的重要污染源,如何进行城市生活垃圾的收集与处理显得至关重要。米东区作为乌鲁木齐市新型工业城区的代表,其经济虽然取得了飞速发展,但其城市居住环境却未得到足够地重视。鉴于此,围绕乌鲁木齐市新型工业城区的生活垃圾分类收集和处理现状展开了社会调查,选取乌鲁木齐市米东区作为靶区,随机选取70户人家进行了入户问卷调查,对调查结果进行了统计分析,得出了乌鲁木齐市米东区家庭生活垃圾分类收集及处理的特点,进而指出了新型工业城区垃圾分类工作存在的主要问题,根据影响城市家庭生活垃圾产生量的因素,针对如何更好的实现垃圾的分类收集工作提出了相应的建议。     

Acquisition feasibility and methane fermentation effectiveness of biomass of microalgae occurring in eutrophicated aquifers on the example of the Vistula Lagoon

This study was aimed at establishing the feasibility of microalgae biomass acquisition from waters of the Vistula Lagoon with the use of an installation operating in the fractional–technical scale, and at determining the effectiveness of biogas production from the acquired substrate. Depending on the technological solution of the concentration process, the degree of aquatic biomass hydration ranged from 99.6 to 97.90%. The quantity of biogas produced during methane fermentation fitted within the range of 243.9 to 395.2 dm³/kg d.m.. The values achieved were found to depend directly on the concentration of organic matter in the acquired water biomass and on system’s loading with a feedstock of organic compounds. The content of methane in a gaseous mixture ranged from 41.4 to 61.9%. The biomass produced was predominated by taxa belonging to Cyanoprokaryota, Bacillarophyceae, and Chlorophyta.     

不产甲烷菌低温降解秸秆粪便试验研究

从发酵沼基中分离出不产甲烷菌菌株,富集培养后,进行分解实验,研究其在较低温度下对各种农业废物的降解性能。研究表明在14.7℃的低温下,接种不产甲烷菌的天然秸秆培养基,在第四天出现温度高峰值点为18.5℃,培养前后温度变化为3.5℃;5d内还原糖下降0.19mg,氨氮下降0.05mg,秸秆利用率为8.67%;堆肥有机质含量6d内下降了10.3mg,甲烷色谱峰面积7d培养后为79.95%;7.4℃的低温下,在第四天出现温度高峰值点为10.5℃,培养前后温度变化为2.5℃;5d内还原糖下降0.15mg,氨氮下降0.02mg,秸秆利用率为6.7%;堆肥有机质含量6d内下降了5.8mg,甲烷色谱峰面积7d培养后为64.42%。     

高寒藏区农牧村家庭能源消费特征及影响因素——以甘南高原为例

能源是消除贫困和实现经济社会与人类发展的重要因素。文章在对甘南高原23个乡镇357个家庭用能资料分析的基础上,研究了高寒藏区农牧村家庭能源消费的特征及主要影响因素。结果表明:1农牧村人均能源消费量为996.05 kgce,以畜粪等生物质能为主,能耗水平高,消费品质差,综合热效率只有18.77%,大部分农牧民还停留在满足基本生存需求的状态;2从牧区到农区,能源消费结构由单一转向多元化,热效率从16.87%提高到23.93%,人均能耗水平逐渐降低,空间阶梯特征明显;3农牧村家庭能源消费模式是多种因素影响的结果,其中牧区主要受生活方式、家庭规模和宗教支出的影响,农牧交错区主要受家庭规模、家庭年收入、家用电器种类和年均取暖时间的影响,农区主要受人均耕地面积、家庭年收入和家庭规模的影响;4结合农牧村实际情况,建议实施牧民定居工程、增加现代能源供给、鼓励使用新能源设备、推广生物质能高效清洁利用技术、强化农牧民的节能环保意识,在保证农牧民基本能源需求的基础上,尽可能减轻能源消费带来的环境压力。     

不同沼灌年限稻田土壤微生物群落分析

为了探明不同沼灌年限稻田耕层土壤微生物群落多样性变化,明确稻田耕层土壤微生物群落多样性对不同沼灌年限的响应,本文原位系统采集了不同沼灌年限的稻田土壤,并采用高通量测序技术对不同沼灌年限稻田土壤的微生物群落结构进行了分析.结果表明,随着沼灌年限的增加,土壤pH值逐渐下降,有机质、硝态氮、磷酸盐等养分逐渐累积.沼灌不利于水稻产量的形成.高通量测序技术较全面和准确地反映了不同沼灌年限稻田土壤微生物群落结构在门、纲、目、科、属这5个水平上的分布,在沼灌稻田微生物群落多样性的表征方面具有明显的优势.随着沼灌年限的增加,稻田土壤微生物群落的物种丰富度逐渐降低,微生物群落的多样性也逐渐降低.典型对应分析的结果表明,土壤溶解性有机碳(F=2.67,P=0.09)是影响沼灌稻田土壤微生物群落结构的主要环境因子.