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.     

EGSB反应器处理产氢发酵液

以厌氧颗粒污泥为接种污泥，对厌氧颗粒污泥膨胀床（EGSB）反应器处理产氢发酵液的启动性能进行了研究。结果表明，在温度为（35±1）℃，水力停留时间（HRT）为6h的条件下，逐渐提高进水COD，经过40d连续运行，EGSB反应器启动成功。容积负荷达到14kgCOD／（m3·d）时，COD去除率约为80％，产气量为26．84L／d，甲烷含量为57．9％。     

移动床生物膜反应器预处理含酚废水

采用两级移动床生物膜反应器（MBBR）预处理高挥发酚含量的石化厂汽提净化水，考察了HRT和DO对废水中挥发酚和COD去除效果的影响。实验结果表明：在两级MBBR总HRT为10 h、MBBR中部废水DO 为1~3 mg/L的条件下， 装置连续运行处理ρ（挥发酚）=110~201 mg/L、COD=644~1 827 mg/L、BOD₅/COD=0.15~0.69的废水，两级MBBR处理后出水平均ρ（挥发酚）为17.6 mg/L，挥发酚去除率达87.9%;平均COD为745 mg/L，COD去除率为32.7%;出水BOD₅/COD平均为0.68，表明经过两级MBBR处理后，废水的可生化性有所提高，有利于废水的后续生化处理。     

盐度对序批式反应器与间歇曝气膜生物反应器污水处理效果的影响

采用序批式反应器(SBR)与间歇曝气膜生物反应器(IAMBR)处理模拟生活污水,考察了进水盐度对两反应器污水处理效果的影响。研究表明,当进水盐度为0g/L(以NaCl质量浓度计,下同)时,SBR和IAMBR对总有机碳(TOC)、NH4+-N及TN的去除能力相当,IAMBR未表现出明显的优势;当进水盐度为10g/L时,SBR和IAMBR对TOC、NH4+-N及TN的去除产生明显的差异。IAMBR因为膜的截留与微生物富集作用,对污染物的去除无明显变化,依然保持了较高的污染物去除率,而SBR受盐度冲击影响较大,TOC、NH4+-N及TN的去除率均大幅降低,说明IAMBR具有较高的抗盐度冲击性能。     

改进隔板絮凝池的数值模拟和实验

通过在廊道中增加了V型穿孔挡板，对传统往复式隔板絮凝池进行了改进，利用数值模拟和实验方法，探讨了改进絮凝池中流态、湍动能（κ）、耗散率（ε）分布情况以及这些参数对絮凝效果的影响。对多种方案进行了优化计算和实验，结果表明，在隔板絮凝池第1个廊道进口1/3和2/3处设置2个120°多孔V型挡板在各种方案中絮凝效果最好，能有效地增加水体紊动，提高絮凝效果，增设V型穿孔挡板后可以适当减少隔板絮凝池长度。     

Optimization of esterification of fatty acid rubber seed oil for methyl ester synthesis in a plug flow reactor

To date, non-food vegetable oil has been considered as the primary source for biodiesel production. Rubber seed oil has high acid value (34 mgKOH/g) and can be used for biodiesel synthesis. The purpose of this study was to investigate esterification of fatty acid, which derived from rubber seed oil, in a plug flow reactor system at high temperature and low methanol consumption. Response surface methodology was applied for design experiment and optimization of esterification reaction. Temperature, methanol consumption, and sulfuric acid were chosen as variables to examine their influence in a conversion to methyl ester. At 140°C, at 5:1 methanol to fatty acid ratio (by mole), H₂SO₄ 1.5 (%v/w), and space time 20 min, the conversion to methyl ester attained 98.2%. Fourier transform infrared spectroscopy (FTIR) and gas chromatography-Mass spectrometry (GC-MS) were used for analysis and to confirm the formation of methyl ester. Methyl ester was characterized for biodiesel fuel properties in accordance to ASTM standard.     

新型厌氧反应器启动运行试验

自行设计了一种新型厌氧反应器,并以模拟高浓度废水为基质,对其进行启动试验研究,考察在负压控制和间歇曝气条件下新型厌氧反应器的运行效果。结果表明:启动阶段COD去除率较高,平均去除率为70%,出水pH和SS稳定,反应器内无浮渣出现。同时,负压条件下反应器内所产沼气可优先分离,产气量及上升速度明显高于正压条件;另外,对反应器沉淀区污泥进行间歇曝气可加速污泥中微气泡的分离。     

气溶胶中烃类有机物居里点热解析-GC/MS联用分析

使用居里点热解析(CPP)-GC/MS联用法对气溶胶中有机化合物进行了分析.结果表明,在使用445℃箔片并保持60s加热、GC-MS 30psi脉冲无分流进样的条件下,目标化合物的分析达到了最佳效果.新建立的CPP-GC/MS联用分析方法中,C16~C26烷烃的检测限为0.04~0.08ng,C27~C34烷烃的检测限为0.1~0.5ng,PAHs的检测限为0.01~0.1ng,藿烷类物质的检测限为0.08ng.标准物质分析的相对标准偏差(RSD)为2.1%~20.6%,PM2.5样品的RSD在3.6%~21.3%,70%的目标化合物的工作曲线的线性(R2)在0.99以上.实验表明,CPP-GC/MS联用的方法能较好地替代传统的溶剂提取法来分析气溶胶中的烃类有机物,尤其是可用于分析颗粒物负载量很小的样品,如多级采样器采集的气溶胶粒径分布样品.     

生物炭载体的表面特征和挂膜性能研究

以花生壳为原料,于300~700℃下热解制备生物炭以作为生物膜载体,对其进行了理化性质表征和挂膜试验.结果表明:较高的热解温度(700℃)能促进生物炭载体孔隙结构发展,生物炭表面ζ电位上升,亲水性增加,从而有利于污水微生物的附着和生长. 挂膜期间,生物炭载体单位挂膜量分别高出陶粒44%~84%,高温(700℃)生物炭载体生物膜对NH4+-N的去除率高出陶粒1%~3%,而中低温(300、500℃)生物炭载体生物膜对NH4+-N的去除率较陶粒低5%~10%,显示生物炭表面理化性质可能对附着的生物膜微生物种类和活性产生影响.     

黔西南高砷煤热解过程中微量元素释放规律研究

采用高温箱式电阻炉对黔西南海子地区煤样进行热解,研究了在300~1200℃下慢速热解过程中,热解温度、元素赋存状态和灰分对微量元素释放规律的影响.结果表明,热解温度是影响煤失重和微量元素挥发的主要原因. As、Mo在900℃以上挥发较快; Pb热解前期挥发较快,450℃以上挥发缓慢;Sb随热解温度的升高缓慢增大.微量元素的挥发性还与赋存状态关系密切,有机态最为活泼;硫化物态和碳酸盐态在热解后期由于矿物的分解而逐步释放;硅酸盐态最稳定,基本残留在灰分中.灰分越高微量元素越不易挥发.