摘要
污泥在生物反应器填埋场内主要是一个厌氧降解的过程,不断发生着各种物理、化学变化。随着填埋时间的增加,污泥的容重、密度、孔隙度和粒度都有不同程度的增加。填埋220d后污泥的孔隙度与土壤的孔隙度相当,当矿化污泥园林绿化或农用时,适宜的孔隙度有利于土壤的保水性和通气透水性,有利于植物根系的发育。污泥平均颗粒粒径和中值颗粒粒径分别从初始的37μm和13μm增加到填埋400d时的143μm和70μm。研究表明:污泥颗粒粒径的增大有利于水分的快速排出以及填埋场的加速沉降。污泥的挥发性有机物(VM)和总有机碳(TOC)含量分别从填埋初期的44.7%和23.5%降到700d时的24.2%和13.5%。在填埋过程中,脱氢酶活性从6.72mgTF/g.6h增加到13.9mgTF/g.6h。大麦和白菜种子发芽率和发芽指数分别从填埋初期的13.8%和18.7%增加到填埋500d时的71.6%和76.5%。大麦和白菜种子都在填埋500d时发芽指数超过60%,污泥可以直接用于园林绿化。随填埋时间的增加,污泥的稳定化程度不断提高,植物毒性逐渐降低。
Sludge in the bioreactor landfill experiences an anaerobic process, including physical and chemical transformation. The bulk density, specific gravity and porosity of sludge are all increased with landfill time. 220 days later after landfill, the porosity of sludge will be the same as that of soil. When the aged-sludge is used in landscaping or agriculture, suitable porosity is beneficial for containing water and ventilation of soil, as well as the growth of plant. 400 days later after landfill, the mean and median particle sizes increased from 37 μm and 13 μm to 143 μm and 70 μm respectively. Studies showed that the increase of particle size was in favor of quick discharging of water and speedup settlement of landfill. The contents of VM and TOC of the sludge decreased from 44.7%, 23.5% to 24.2%, 13.5% after 700 days＇ landfill. Dehydrogenase activity increased from 6.72 mg TF/g.6h to 13.9 mg TF/g.6h correspondingly. The germinate indexes of barley and cabbage in the sludge increased from 13.8% and 18.7% to 71.6% and 76.5 % after 500 days＇ landfill respectively. The sludge that has been in landfill for 500 days could be used in park virescence directly. Stabilization degree of sludge increased with landfill time, while the plant toxicity of sludge decreased with landfill time.
出处
《生态环境学报》
CSCD
北大核心
2009年第4期1207-1212,共6页
Ecology and Environmental Sciences
基金
教育部重大专项(305005)
关键词
污泥填埋
孔隙度
粒径
发芽指数
VM
TOC
sludge landfill
porosity
particle size
germination index
VM
TOC
