复合填料地下渗滤系统的强化脱氮研究

Denitrification intensified of compound mixed subsurface wastewater infiltration system

摘要:

为有效提高地下渗滤系统的运行水力负荷并强化其脱氮效果，建立了由55%煤渣、25%土壤与20%草炭全混合装填的地下渗滤装置，运行水力负荷为10cm•d-1，每天进水4次，通过改变不同运行条件来促进总氮的去除。研究结果表明该装置对COD、NH4+-N、TN的平均去除率，在正常出水水位条件下运行，分别为73.4%、98.2%、20.1%；在提高出水水位条件下运行，分别为75.4%、79.1%、26.9%；在添加碳源条件下运行，分别为88.9%、88.5%、55.7%。说明草炭的添加并不能明显提高TN的去除率，而出水水位的提高，可促进系统内厌氧环境的形成从而有利于总氮的去除，但同时也会降低氨氮的去除效果；添加碳源可明显提高总氮的去除效果，使系统出水总氮质量浓度由正常出水水位条件下的22.8 mg•L-1下降到14.2 mg•L-1，且对COD、NH4+-N去除效果的影响不大。因此，影响该系统去除总氮的关键因素是碳源的缺乏。

Abstract:

In order to improve the hydraulic permeability and intensify denitrification of subsurface wastewater infiltration system, one apparatus was established in a pilot laboratory with the mediums of 55% cinder, 25% soil and 20% grass carbon mixed completely. The apparatus was dosed 4 times daily with domestic wastewater at 10 cm•d-1. Operating conditions were changed in order to improve the removal efficiency of TN. The average removal efficiency of COD, NH4+-N, TN were 73.3%, 98.2%, 20.1%, respectively, when outlet location was at normal position; The average removal efficiency of COD, NH4+-N, TN were obtained 75.4%, 79.1%, 26.9%, respectively, When outlet location was heightened 30 cm, the bottom of apparatus was submerged so that anaerobic environment was formed; The average removal efficiency of COD, NH4+-N, TN were obtained 88.9%, 88.5%, 55.7%, respectively, when the apparatus was conducted in glucose added in domestic wastewater. The results showed that the removal of TN was not been improved by adding grass carbon in apparatus; outlet location raised could increased TN removal efficiency from 20.1% to 26.9%, but the action was limited; the glucose added could increased TN removal efficiency from 26.9% to 55.7%, and TN concentration of effluent decreased from 22.8 mg•L-1 to 14.2 mg•L-1; at the same time, the removal of COD, NH4+-N had not been affected. So the critical factor of the TN removal blocked was carbon absent.