生物填料地下渗滤系统对生活污水的脱氮

将草甸棕壤、炉渣和活性污泥等基质按体积比13∶6∶1配制生物填料,研究了生物填料地下渗滤系统（subsurface wastewater infiltration system,SWIS）在不同的水力负荷和污染负荷条件下对校园生活污水的脱氮效果。场地实验结果表明,当BOD5负荷为12.0 g BOD5/（m2·d）,表面水力负荷为0.04-0.10 m3/（m2·d）时,SWIS对NH＋4-N和TN的平均去除率分别为92.4%和82.0%。当水力负荷为0.08 m3/（m2·d）,BOD5负荷9.3-16.8 g BOD5/（m2·d）时,SWIS对NH＋4-N和TN的平均去除率为92.7%和81.2%。SWIS中氧化还原电位（oxygen reduction potential,ORP）随进水水力负荷和BOD5负荷的增加而降低,脱氮效率下降。综合出水水质和处理效率,适宜的水力负荷和污染负荷分别为0.065 m3/（m2·d）和12.0 g BOD5/（m2·d）。在此条件下,SWIS的启动周期为25-30 d。出水水质均优于《城市污水再生利用-景观环境用水水质》（GB/T18921-2002）标准,且处理效果稳定,抗负荷冲击能力强。

Nitrogen removal in domestic sewage by bio-substrate based subsurface wastewater infiltration system

A kind of novel bio-substrate was made,which was composed of meadow brown soil,coal slag and dewatered sludge with volume ratio of 13∶ 6∶ 1.Nitrogen removal efficiency was measured for a bio-substrate based subsurface wastewater infiltration system（SWIS）.The field study showed that mean removal efficiency for NH＋ 4-N and TN were 92.4% and 82.0%,respectively when the BOD 5 loading and hydraulic loading rate were 12.0 g BOD 5 /（m2·d） and 0.04 -0.10 m3/（m2·d）,respectively.While the hydraulic loading and BOD 5 loading rate were 0.08 m3/（m2·d） and 9.3 -16.8 g BOD 5 /（m2·d）,the removal efficiency were 92.7% for NH＋ 4-N and 81.2% for TN.Oxygen reduction potential（ORP） values and nitrogen removal efficiency reduced with an increase in hydraulic and pollutant loading rates.Taking the effluent quality and treatment efficiency into consideration,the optimal hydraulic and pollutant loading rate were 0.065 m3/（m2·d） and 12.0 g BOD 5 /（m2 ·d）,respectively.Under the conditions,the start-up period of the SWIS was 25 -30 d.The effluent quality was superior to the standard of GB / T18921-2002.The bio-substrate based SWIS has stable treatment efficiency and strong resistance to impact loadings.