连续流分段进水短程反硝化-厌氧氨氧化耦合工艺的反硝化脱氮特性

NITROGEN REMOVAL CHARACTERISTICS OF A STEP-FEED CONTINUOUS FLOW PARTIAL DENITRIFICATION-ANAEROBIC AMMONIUM OXIDATION COUPLED WITH DENITRIFICATION PROCESS

采用连续流分段进水短程反硝化-厌氧氨氧化(partial denitrification-anaerobic ammonium oxidation,PD-Anammox)耦合反硝化工艺处理低C/N生活污水,研究了污染物去除、典型周期COD及氮素沿程变化特征、短程反硝化-厌氧氨氧化和反硝化对TN去除贡献。结果表明:在平均进水ρ(COD)、ρ(NH^(+)_(4)-N)、ρ(TN)为193.1,58.6,60.3 mg/L的条件下,系统出水平均ρ(COD)、ρ(NH^(+)_(4)-N)、ρ(TN)分别为46.3,1.5,13.4 mg/L,低于GB 18918—2002《城镇污水处理厂污染物排放标准》一级A标准。采用NO^(-)_(3)-N预缺氧和进水点后置,可实现缺氧区NO^(-)_(3)-N→NO^(-)_(2)-N转化,同时完成厌氧氨氧化过程;缺氧区设置厌氧氨氧化悬浮填料,可提高系统TN去除率。通过缺氧区物料衡算,缺氧1区厌氧氨氧化对TN去除贡献率(ΔPD-Anammox/ΔTN)均值为54.37%,缺氧2区的ΔPD-Anammox/ΔTN均值为64.17%。

The low C/N domestic sewage was treated by a step-feed continuous flow partial denitrification-anaerobic ammonium oxidation(PD-Anammox) process coupled with denitrification,the pollutants’ removal characteristics,pollutants’ concentrations in different stages of the system at a typical operation cycle,and total nitrogen(TN) removal contribute efficiencies of PD-anammox and denitrification were studied.The results showed that when the average influent concentrations of COD,NH^(+)_(4)-N,and TN were 193.1,58.6 and 60.3 mg/L respectively,their effluent concentrations were 46.3,1.5,and 13.4 mg/L respectively,complying with the first level A criteria specified in the Discharge Standard of Pollution for Municipal Wastewater Treatment Plants(GB 18918—2002).The nitrate transformed to nitrite in anoxic by nitrate pre-starvation and post-inlet to provide the anammox matrix of nitrite and ammonium.The TN efficiency got improved by setting anammox filler in the anoxic zones.The average PD-Anammox process’ s contribution rates to TN removal of anoxic zone Ⅰ and Ⅱ were 54.37% and 64.17% respectively,through mass balance calculation at the anoxic zones.