浅水体浮萍污水净化系统的除氮途径

以稀释的猪场厌氧污水为供试水样,少根紫萍为供试生物材料,对夏、冬2季浅水体浮萍污水净化系统TN、NH4 -N和NOx--N(NO2--N与NO3--N之和)的去除途径进行了试验研究。结果表明,在夏季气温条件下,TN通过气态氨挥发、浮萍系统吸收/吸附NH4 -N和NOx--N得以去除,3途径去除的N分别占TN去除量的30.5%、15.9%和53.6%;NH4 -N通过气态氨挥发、浮萍系统吸收/吸附和硝化反应得以去除,3途径去除的N分别占NH4 -N总去除量的33.1%、17.3%和49.6%;NOx--N则完全通过浮萍系统吸收/吸附得以去除。在冬季气温条件下,TN通过气态氨挥发和浮萍系统吸收/吸附NH4 -N得以去除,2途径去除的N分别占TN去除量的31.7%和68.3%;NH4 -N通过气态氨挥发、浮萍系统吸收/吸附和硝化反应得以去除,3途径去除的N分别占NH4 -N总去除量的28.9%、69.5%和1.6%;而水体中的NOx--N含量始终保持稳定。

Nitrogen Removal Pathways in Shallow-Water Duckweed-Based Wastewater Treatment Systems

With diluted anaerobically pretreated wastewater from a pig farm and Spirodela oligorrhiza,TN,NH~ _4-N and NO~-_x-N removal pathways in shallow-water duckweed-based wastewater treatment systems were studied in summer and winter.Results show that,in summer,30.5% of the TN was removed through ammonia volatilization and 15.9% and 53.6% of NH~ _4N and NO~-_x-N through duckweed uptake/adsorption,respectively,and 33.1%,17.3% and 49.6% of NH~ _4-N through ammonia volatilization,duckweed uptake/adsorption and nitrification,respectively,and duckweed uptake/adsorption was the only pathway for removal of NO~-_x-N.While in winter,31.7% and 68.3% of the TN was removed through ammonia volatilization and NH~ _4-N uptake/adsorption by duckweeds,respectively,28.9%,69.5% and 1.6% of the NH~ _4-N through ammonia volatilization,duckweed uptake/adsorption and nitrification,respectively,and the content of NO~-_x-N,however,remained unchanged.