压力变化对活性污泥脱氮除磷效能的影响

High pressure aeration enhancing nitrogen and phosphorus removal efficiency of activated sludge system for treating domestic wastewater

曝气压力对活性污泥工艺的运行效能具有较大影响,通过改变曝气压力,考察了活性污泥系统中硝化反硝化、生物除磷等过程的性能变化,论述了曝气压力变化对活性污泥脱氮除磷的强化效果.试验结果表明,恒定高压力曝气和高压变压力曝气均可强化活性污泥对水中污染物的高效快速降解效能.恒定曝气压力下,在0.5～0.7 MPa左右时,污染物的去除效果最优,COD在3 h内降解至100mg/L以下,去除率大于80%,出水氨氮在15 mg/L以下,去除率在60%以上,出水TP在0.5 mg/L以下,去除率约为95%.高压变曝气压力下,当压力变化间隔为20 min,即总运行时长为140 min时,污染物下降趋势最明显,出水COD约为100 mg/L左右,去除率大于60%,出水氨氮约20 mg/L左右,去除率约为50%,TP低于0.5mg/L,去除率高于95%.

Aeration pressure has a positive impact on the performance of activated sludge process. This paper investigated the performance of nitrification,denitrification and biological phosphorus removal process in an activated sludge system for treating domestic wastewater under different aeration pressures. The enhancing effect on nutrients removal efficiency was illustrated under high aeration pressure. Results showed that an optimal performance was achieved when the aeration pressure ranged from 0. 5 to 0. 7 MPa under the constant aeration pressure operation with the operational time of 3 h. Effluent COD was below 100 mg / L（ removal efficiency exceeded 80%）. Ammonium nitrogen was less than 15 mg / L in effluent（ removal efficiency maintained at 60%）. Effluent TP was kept at 0. 5 mg /L with the removal efficiency of 95%. When the internal time of aeration pressure change was 20 min（ total operation time was about 140 min）,an obvious nutrients removal trend emerged under the varying aeration pressure operation. Effluent COD was kept at 100 mg / L（ removal efficiency exceeded 60%）. Ammonium nitrogen was less than 20 mg / L in effluent（ removal efficiency was about 50%）. Effluent TP was less than 0. 5 mg / L with the removal efficiency of 95%.