ABSTRACT

Ecological floating bed (EFB) with assembling substrate can effectively enhance the removal of nitrogen. However, the influence of the substrate on the operation process of the EFB remains unclear. In this study, EFBs with zeolite, sponge iron and complementary substrates (zeolite and sponge iron) were established to explore the effects of different substrates on nitrogen removal efficiency, physical and chemical properties and plant growth. Complementary substrates could efficiently and stably remove nitrogen from tailwater. The concentration of ammonium nitrogen (NH₄⁺-N), nitrate nitrogen (NO₃^--N) and total nitrogen (TN) in the effluent during the operation were lower than 1, 1 and 1.5 mg/L, respectively. Additionally, complementary substrates had no inhibitory effect on plant growth, and those substrates had little influence on the distribution of dissolved oxygen (DO), the oxidation–reduction potential (ORP) and the pH value. The zeolite increased the NH₄⁺-N removal and promoted the growth of plant stems and roots. However, sponge iron could effectively remove the NO₃^--N in the water body and inhibit the growth of plants. These results can provide a basis for the EFB in the reuse of the tailwater of wastewater treatment plant.

摘要

带有组装基体的生态浮床（EFB）可以有效地提高氮的去除率。然而，基板对EFB运行过程的影响尚不清楚。本研究建立了具有沸石、海绵铁和互补底物（沸石和海绵铁）的 EFB，以探讨不同底物对脱氮效率、理化性质和植物生长的影响。互补底物可以有效、稳定地去除尾水中的氮。铵态氮（NH ₄ ⁺ -N）、硝态氮（NO ₃ ^--N)和运行过程中出水总氮(TN)分别低于1、1和1.5mg/L。此外，互补底物对植物生长没有抑制作用，并且这些底物对溶解氧（DO）的分布、氧化还原电位（ORP）和pH值几乎没有影响。沸石增加了NH ₄ ⁺ -N的去除，促进了植物茎和根的生长。而海绵铁能有效去除水体中的NO ₃ ^- -N，抑制植物生长。这些结果可为EFB在污水处理厂尾水回用中提供依据。