水力负荷对生态槽深度处理农村生活污水的影响

研究水力负荷对生态槽深度处理农村生活污水效果的影响。结果表明：出水溶解氧随水力负荷增大而降低，当水力负荷为52．90L·d^-1·m^-2和90．20L·d^-1·m^-2之时，出水溶解氧在3．00mg·L^-1以上；当水力负荷增至129．40L·d^-1·m^-2，溶解氧降至0．60mg·L^-1以下。水力负荷增大不利于化学需氧量的去除，当水力负荷由52．90L·d^-1·m^-2之增至90．20L·d^-1·m^-2，化学需氧量平均去除率降低16．70％。随水力负荷增大，出水氨氮、总氮和总磷均呈上升趋势，水力负荷达129．40L·d^-1·m^-2之时，出水氨氮和总磷分别升至1．34mg·L^-1和0．11mg·L^-1，仍分别可达GB3838—2002《地表水环境质量标准》Ⅳ类和Ⅲ类水体标准。但总氮尚难以达到GB3838—2002之V类水标准。

Hydraulic loading rate for rural domestic sewage treatment with an eco-tank

To evaluate the effect of a hydraulic loading rate on an advanced treatment of rural domestic sewage, an eeo-tank consisting of three rectangular tanks（2.0 m × 0.5 m ×0.5 m） was sequentially connected with a floating aquatic plant of either Pistia stratiotes, Hydrocotyle leucocephala, or Myriophyllum aquaticum planted in each. Water samples were collected daily and analyzed for water quality properties including dis- solved oxygen, chemical oxygen demand （COD）, ammonium nitrogen （N）, nitrate-N, nitrite-N, total-N, and total phosphorus（P）. Results showed that effluent dissolved oxygen concentration declined with an increase in hydraulic loading rate. When hydraulic loading rates were 52.90 L .d^-1.m^-2 and 90.20 L.d^-1.m^-2, effluent dissolved oxygen concentration was more than 3.00 mg.L-t. However, as the hydraulic loading rate increased to 129.40 L-d.m^-2, dissolved oxygen dropped below 0.60 mg.L^-1. The increase in hydraulic loading rate did not promote COD removal. When the average hydraulic loading rate increased from 52.90 L.d^-1.m^-2 to 90.20 L-d^-1.m^-2, the average COD removal efficiency dropped 16.70%. Also, effluent concentrations of ammonium-N, total-N, and total P increased with an increase in the hydraulic loading rate. When the hydraulic loading rate was 129.40 L-d-l-m-z, effluent concentrations of ammonium-N national environmental quality standard for surface water, increased to 1.34 mg-Lq meeting the fourth class and total P increased to 0.11 mg＇L-1 meeting the third class standard. However, total-N concentration did not reach the fifth class surface water standard. Thus, the Eco-tank was efficient in removing aqueous pollutants as the hydraulic loading rates varying from 52.90 L-d^-1.m^-2 to 129.40 L.d.m^-2.