应用MBBR进行PU合成革废水的脱氮研究

采用一个缺氧/好氧MBBR反应器考察其对TN、NH3-N和有机物的去除,同时采用另一个缺氧MBBR反应器,考察其对NO3--N的去除。试验结果表明:当进水TN的质量浓度为150~300 mg/L,NH3-N的质量浓度为50 mg/L浓度时,缺氧/好氧MBBR对TN和NH3-N的平均去除率大于89.7%和84.0%,出水TN和NH3-N均能达到GB 21902—2008《合成革与人造革工业污染物排放标准》中规定的要求(ρ(NH3-N)8 mg/L,ρ(TN)15mg/L)。当碳氮比较低时,产生NO2--N的积累,对缺氧/好氧MBBR处理合成革废水而言,维持其碳氮比在3.5左右即可实现有效脱氮。缺氧MBBR反硝化能去除约98.2%的NO3--N和NO2--N,初始时碳氮比较低,产生NO2--N的积累,当碳氮比继续升高时,TN浓度下降,说明当NO3--N的质量浓度高达300 mg/L时,缺氧MBBR的反硝化效果显著。

Nitrogen removal of wastewater from PU synthetic leather production by MBBR

Anoxic-aerobic MBBR was used to remove TN, NH3-N and organic matters, while anoxic MBBR was used to remove NO3--N. The test results showed that, when the mass concentrations of TN and NH3-N of the influent water were 150 ~ 300 and 50 mg/L respectively, the removal rates of them by anoxic-aerobic MBBR were above 89.7% and 84.0% respectively, the effluent water quality could meet the relevant requirement of GB 21902-2008 Emission Standard of Pollutants for Synthetic Leather and Artificial Leather Industry(ρ(NH3-N) <8 mg/L, ρ(TN) < 15 mg/L). As low carbon-nitrogen ratio could result in NO2--N accumulation, maintaining carbon-nitrogen ratio at about 3.5 during the process of PU synthetic leather wastewater treatment by MBBR could realize an effective removal of nitrogen. On the other hand, about 98.2% of NO3--N and NO2--N were re-moved by anoxic MBBR, when the carbon-nitrogen ratio was low, NO2--N accumulation was exist; however, when the carbon-nitrogen ratio was increasing continuously, the TN concentration decreased, which indicated that, an outstanding denitrification performance of the anoxic MBBR could be obtained when the mass concentration of nitrate nitrogen was as high as 300 mg/L.