曝气频率对生物反应器渗滤液与填埋气的影响

传统生物反应器填埋场长期以来存在酸化阶段过长和能源回收利用率低等问题。上层垃圾好氧处理可有效实现垃圾快速降解与集中甲烷化。为探究好氧处理阶段不同曝气频率对生物反应器填埋场运行效果的影响,设置厌氧生物反应器A1作为对照,曝气频率不同的上层曝气式生物反应器C1和C2为实验组进行实验。结果表明,上层垃圾好氧处理可有效改善填埋柱内高浓度挥发性脂肪酸(VFA)累积现象,缩短酸化阶段,促进甲烷化环境建立。至曝气结束,C1和C2填埋柱内渗滤液COD低于30 000 mg/L,VFA浓度降也降低到10 000 mg/L以下。好氧处理阶段,增大曝气频率可提高填埋垃圾对渗滤液pH的缓冲作用,扩大甲烷化面积,促进高浓度甲烷化过程的快速发生。与C1相比,曝气频率较高的C2反应器提前15 d达到pH为7的预处理要求,曝气阶段氨氮浓度经历先上后下,填埋柱日产甲烷量700 mL,约为C1产气能力的2倍。但考虑到实际氧气利用率与经济性能问题,曝气频率的选择不宜过大。     

生物反应器填埋的沉降加速效应

通过实验室填埋柱模拟实验,研究了生物反应器填埋操作方式对填埋层沉降的影响。结果表明：与传统卫生填埋方式相比,回灌经厌氧生物处理后渗滤液的生物反应器填埋方式能够加速填埋层的沉降,140 d内沉降提高比例达10%以上。我国填埋垃圾高含水率、高易腐有机物含量的特性,使得其填埋层的次沉降系数高于文献值。填埋垃圾有机物降解量及其引起的垃圾水分排出量与填埋层沉降有显著相关性,表明有机物降解是引起填埋层沉降的重要因素,也是造成生物反应器填埋与传统卫生填埋方式初期沉降差异的主要原因。     

Bio-immobilization of Cu and Zn in recirculated bioreactor landfill

Purpose  

To protect the environmental quality of soil, groundwater, and surface water near the landfill site, it is necessary to make an accurate assessment of the heavy metal mobility. This study aims to present the bio-immobilization behavior of heavy metals in landfill and provide some reference suggestion for the manipulation of heavy metal pollution control after closure.     

矿化污泥生物反应器处理生活垃圾填埋场老龄渗滤液

经长时间稳定化形成的矿化污泥中,含有种类丰富和数量繁多的降解性微生物,具有处理渗滤液的潜力。建立3个矿化污泥生物反应器,即C1(粉煤灰0%),C2(粉煤灰9.1%),C3(粉煤灰16.7%),以处理垃圾填埋场老龄渗滤液。在单级矿化污泥反应器中,当进水COD和NH3-N分别约为1350和900 mg/L时,水力负荷为17.7～70.8 L/(m3.d),COD去除率可超过65%,氨氮的去除率可超过94%。粉煤灰的加入一定程度上降低了COD去除率,但有助于氨氮的去除。在二级矿化污泥生物反应器中(即C3～C1串联),水力负荷为35.4 L/(m3.d)的工况下,当COD、TOC、IC和NH3-N分别为1 500～2 500,500～900,1 200～1 600和1 200～1 450 mg/L时,出水可达到COD<300 mg/L,TOC<180 mg/L,IC<100 mg/L,NH3-N<5 mg/L。但是,矿化污泥生物反应器对渗滤液总氮的去除率较低,仅为20%左右。     

Methane oxidation in a landfill biowindow under wide seasonally fluctuating climatic conditions

Environmental Science and Pollution Research - In the current study, a pilot biowindow was constructed in a closed cell of a Canadian Landfill, undergoing high seasonal fluctuations in the...     

城市生活垃圾半好氧生物反应器填埋技术试验研究

对城市生活垃圾半好氧生物反应器填埋技术与传统垃圾填埋技术进行了对比试验,由试验结果可知,半好氧生物反应器填埋技术可缩短填埋垃圾产酸时间,净化渗滤液,加速填埋垃圾稳定化进程.城市生活垃圾半好氧生物反应器填埋技术是中国中小城市垃圾填埋处理的发展方向.     

生物反应器填埋场技术发展现状及研究前景

生物反应器填埋场是近20年来发展起来的一种新的填埋方式,通过回灌渗滤液等控制手段,改善填埋场内部微生化环境,加速填埋场稳定化进程。生物反应器填埋场的关键在于渗滤液收集系统、防渗系统、气体收集系统和渗滤液回灌系统。一些运行的全规模生物反应器填埋场证明了这种操作方式能加快垃圾降解和填埋气体的产生,减少渗滤液处理量。然而还有一些经济和技术上的不确定性,包括持久有效性、压实度、结构特性、氧化一还原环境和费用一效益分析等因素,都需要进一步研究。我国城市垃圾处理方式主要是填埋,这种新型的填埋场在我国将会有很好的前景,防渗层性能、临时覆盖、建设形式和监测手段等问题是其发展的主要障碍。     

生物反应器填埋场产甲烷规律的模拟研究

生物反应器填埋场是一种新型的垃圾卫生填埋场，可以加速填埋场的稳定及甲烷的产生。通过模拟试验探讨了生物反应器填埋场在不同操作条件下的产甲烷情况及COD、pH值的变化趋势。试验证明较高的回灌频率有助于垃圾降解、产甲烷速率的升高及渗滤液中COD浓度的降低；污泥接种起缓冲作用，使垃圾的降解及产气速率更趋向平稳；甲烷的产生与COD的降低是同步进行的，因此可以通过COD的变化趋势来判断产甲烷情况。研究建立了反映垃圾含水率影响填埋场产甲烷的数学模型，该模型具有简便、直观、准确等优点。     

Heavy metals mobility in full-scale bioreactor landfill: initial stage

Selected heavy metals (HMs) including Cd, Cr, Cu, Ni, Pb and Zn initially released from a full-scale bioreactor landfill were monitored over the first 20 months of operation. At the initial landfill stage, the leachate exhibited high HMs release, high organic matter content (27000-43000gl(-1) of TOC) and low pH (5-6). By the fifth month of landfilling, the methanogenic stage had been established, and HMs release was reduced below the Chinese National Standards. Total released HMs accounted for less than 1% of landfill deposited during the investigated period. Most landfill HMs were inorganic. Fourier-transform infrared (FT-IR) spectra data and model calculations using Visual MINTEQ indicated that humic substances strongly affected the mobility of organic fractions of HMs in the methanogenic landfill. The initial rates of HMs release could be enhanced by recycling the leachate back to bioreactor landfill, but the total quantity released may be reduced by early establishment of methanogenic stage in bioreactor landfill.     

生物反应器填埋场产甲烷规律的模拟研究

生物反应器填埋场是一种新型的垃圾卫生填埋场,可以加速填埋场的稳定及甲烷的产生.通过模拟试验探讨了生物反应器填埋场在不同操作条件下的产甲烷情况及COD、pH值的变化趋势.试验证明较高的回灌频率有助于垃圾降解、产甲烷速率的升高及渗滤液中COD浓度的降低;污泥接种起缓冲作用,使垃圾的降解及产气速率更趋向平稳;甲烷的产生与COD的降低是同步进行的,因此可以通过COD的变化趋势来判断产甲烷情况.研究建立了反映垃圾含水率影响填埋场产甲烷的数学模型,该模型具有简便、直观、准确等优点.     

Methane and carbon dioxide emissions from closed landfill in Taiwan

The atmospheric concentrations and emission rates of CH(4) and CO(2) were studied at three sites of the Fu-Der-Kan closed landfill and after as the multi-use recreational park in northern Taiwan. Atmospheric CH(4) and CO(2) concentrations of closed landfill were 1.7-4.6 and 324-409ppm, respectively. CH(4) and CO(2) emission rates ranged from 8.8 to 163mg m(-2)h(-1) and from 495 to 1531mg m(-2)h(-1), respectively. Diurnal variation was noted with higher values at night than those in daytime. After creation of the park, atmospheric CH(4) and CO(2) concentrations were 1.8-3.1 and 332-441ppm, respectively. CH(4) and CO(2) emission rates ranged from -1.1 to 2.3mg m(-2)h(-1) and from -135 to 301mg m(-2)h(-1), respectively. There were no notable diurnal variations in either atmospheric concentrations or emission rates.     

间歇式生物反应器填埋结构对渗滤液水质的影响研究

通过2套间歇式生物反应器填埋模拟装置开展实验,对不同填埋结构下垃圾降解前期渗滤液pH值、COD、NH 4＋-N、VFA以及渗滤液产生量的变化规律进行了对比研究。实验结果表明：间歇式生物反应器填埋方式能够有效抑制填埋初期渗滤液pH值的快速下降,渗滤液采取部分回灌能有效降低NH4＋-N浓度的积累,新鲜垃圾与半腐熟垃圾分层并...     

塔式矿化垃圾生物反应床处理垃圾填埋场渗滤液的效能研究

通过正交试验研究了固液比、进水COD和运行周期对塔式矿化垃圾生物反应床处理垃圾渗滤液的性能影响.小试试验结果表明,在温度为10～37 ℃条件下,固液比是影响污染物去除性能的关键因素.现场中试研究表明,在水力负荷为0.267～0.444 m3/d(以每立方米矿化垃圾计)条件下,出水COD和出水氨氮基本满足国家二级排放标准.塔式矿化垃圾生物反应床是一种高效低耗的垃圾渗滤液处理工艺.     

陈垃圾反应床＋芦苇人工湿地处理垃圾渗滤液

研究了陈垃圾反应床与芦苇人工湿地串联对垃圾渗滤液中污染物的去除效果, 并探讨了湿地中芦苇生长和对渗滤液中总氮的吸收能力。结果表明： 在进水负荷为0.1 m³/（m²·d）的条件下,经过3个月的运行,陈垃圾反应床与芦苇人工湿地对陈年渗滤液中COD、氨氮、总氮及总磷的最大去除率分别达到90.3%、95.0%、79.3%和99.8%。通过对人工湿地中芦苇的分析表明,芦苇在6—8月份生长迅速,地上部分生物量与其氮含量增加较快,最大值均出现在8月底,植株总含氮量可以达到28.5 g/m²。此时收割芦苇可从湿地中最大限度除氮。如能增加芦苇种植密度,陈垃圾床与芦苇湿地串联处理渗滤液污染物以及深度去氮是可行的。     

Effect of alkalinity on the performance of a simulated landfill bioreactor digesting organic solid wastes

This study investigated the effects of alkalinity on the anaerobic treatment of the organic solid wastes collected from the kitchen of Engineering Faculty in Dokuz Eylul University, Izmir, Turkey and the leachate characteristics treated in three simulated landfill anaerobic bioreactors. All of the reactors were operated with leachate recirculation. One reactor was operated without alkalinity addition. The second reactor was operated by the addition of 3 g l-1 d-1 of NaHCO3 alkalinity to the leachate and the third reactor was operated by the addition of 6 g l-1 d-1 NaHCO3 alkalinity to the leachate. After 65 d of anaerobic incubation, it was observed that the chemical oxygen demand (COD), volatile fatty acids (VFA) concentrations, and biochemical oxygen demand to chemical oxygen demand (BOD5/COD) ratios in the leachate samples produced from the alkalinity added reactors were lower than the control reactor while the pH values were higher than the control reactor. The COD values were measured as 18900, 3800 and 2900 mg l-1 while the VFA concentrations were 6900, 1400 and 1290 mg l-1, respectively, in the leachate samples of the control, and reactors containing 3 g l-1 NaHCO3 and 6 g l-1 NaHCO3 after 65 d of anaerobic incubation. The total nitrogen (TN), total phosphorus (TP) and ammonium nitrogen (NH4-N) concentrations in organic solid waste (OSW) significantly reduced in the reactor containing 6 g l-1 NaHCO3 by d 65. The values of pH were 6.54, 7.19 and 7.31, after 65 d of anaerobic incubation, respectively, in the aforementioned reactors results in neutral environmental conditions in alkalinity added reactors. Methane percentage of the control, reactors containing 3 g l-1 NaHCO3 and 6 g l-1 NaHCO3 were 37%, 64% and 65%, respectively, after 65 d of incubation. BOD5/COD ratios of 0.27 and 0.25 were achieved in the 3 and 6 g l-1 NaHCO3 containing reactors, indicating a better OSW stabilization. Alkalinity addition reduced the waste quantity, the organic content of the solid waste and the biodegradation time.     

冬季垃圾填埋场渗滤液回灌水量平衡的实验研究

渗滤液回灌的水量平衡是垃圾填埋场渗滤液回灌处理法工程应用的关键问题之一。着重研究了冬季渗滤水回灌的水量平衡状况。结果表明,冬季回灌水量仍可通过土壤蒸发得到大量削减,径流量、土壤渗出 水与下渗水的比值大于春夏秋三季,平均蒸发量小于些三季。回灌条件下,土壤湿润度提高,蒸发量增大。     

渗滤液回灌比例对好氧生物反应器填埋场稳定化进程的影响

为研究回灌比例对好氧生物反应器填埋场稳定化进程的影响,探讨了回灌比例为15%、20%、25%、30%和全回灌（体积分数）时,反应器所产渗滤液及填埋垃圾性质在不同回灌比例下变化的趋势,填埋周期为198 d。结果表明：回灌比例为25%的反应器所产渗滤液中的氨氮于135 d达到GB 16889-2008所规定的垃圾填埋场渗滤液氨氮排放浓度限值,较其他反应器提前3~49 d,整个填埋周期所产还原性有机物较其他回灌量低2.11%~20.16%;且有机垃圾降解速度最快,至填埋结束时,沉降率为75.13%,比其他反应器多0.87%~2.63%,总有机质和纤维素含量分别为48.47%和7.39%,较其他回灌比例分别低0.61%~5.52%和0.2%~0.64%,表明25%的回灌比例有利于快填埋场的稳定化进程。     

渗滤液回灌频率对生物反应器填埋场的影响研究

通过模拟实验研究了渗滤液回灌周期为1、2、3和5 d的4个模拟垃圾柱的产甲烷过程和渗滤液水质的变化情况.在用NaOH调节回灌渗滤液pH值的前提下,回灌频率越高,模拟厌氧型生物反应器填埋垃圾柱先开始产甲烷,但当回灌周期低于3 d时,开始产甲烷的时间相差不多.从渗滤液水质看,回灌周期为3 d的垃圾柱渗滤液COD、VFA等有机污染物浓度下降最快.综合考虑启动时间、运行费用和填埋场的稳定进程,在厌氧型生物反应器填埋场中,实施3 d/次的渗滤液回灌频率最为合适.     

Methane and carbon dioxide emissions from Shan-Chu-Ku landfill site in northern Taiwan

To investigate the methane and carbon dioxide emissions from landfill, samples were taken of material up to 5 years old from Shan-Chu-Ku landfill located in the northern part of Taiwan. Atmospheric concentrations of carbon dioxide, methane and nitrous oxide ranged from 310 to 530, 2.64 to 20.16 and 0.358 to 1.516 ppmv with the measurement of gas-type open-path Fourier transform infra-red (FTIR) spectroscopy during February 1998 to March 2000, respectively. Average methane emission rate was 13.17, 65.27 and 0.99 mgm(-2)h(-1) measured by the gas chromatography chamber method in 1-2, 2-3 and 5 year-old landfill, respectively. Similarly, average carbon dioxide emission rate was 93.70, 314.60 and 48.46 mgm(-2)h(-1), respectively. About 2-3 year-old landfill had the highest methane and carbon dioxide emission rates among the tested areas, while 5 year-old landfill was the least. Methane emission rate at night in most tested locations was higher than that in the daytime. Total amount of methane and carbon dioxide emission from this landfill was around 171 and 828 ton in 1999, respectively.     

Urban Air Pollution in Latin America and the Caribbean

Urban air pollution has become an increasing problem in Latin America and the Caribbean. One reason is the rapid expansion in the size of the urban population. This phenomenon is associated with an increase in the number of vehicles and in energy utilization which, in addition to industrial processes often concentrated in the cities, are the primary sources of air pollution in Latin American cities. The air quality standards established in such countries are frequently exceeded although control programs have been implemented. The urban areas more affected by anthropogenic pollutant emissions are Sao Paulo, Brazil; Santiago, Chile; and Mexico City. In Latin America, the population of cities with high priority air pollution problems include approximately 81 million people or 26.5 percent of the total urban population of Latin America, corresponding to 30 million children (< 15 years), 47 million adults (15-59 years) and 4 million elderly people (≧60 years) who are exposed to air pollutant levels that exceed World Health Organization (WHO) guidelines for adequate health protection.