固体碳源填充床反应器反硝化性能的研究

为了优化固体碳源填充床反应器的运行条件，以PLA/PHBV颗粒为碳源和生物膜载体，研究了水力负荷与硝态氮负荷对反应器反硝化性能的影响，并用扫描电镜观察碳源表面生物膜的形态。结果表明，在进水硝态氮浓度为100 mg·L-1，水力负荷为1.71~8.39 m3·m-2·d-1时，反硝化速率呈现先增加后降低的趋势，最大值为40.53 mg·L-1·h-1；随着水力负荷的提高，出水硝态氮浓度逐渐增加，而COD浓度逐渐降低；维持水力负荷在3.54 m3·m-2·d-1以下，可保证反应器的出水满足我国饮用水标准对硝态氮与亚硝态氮浓度的要求；维持水力负荷为5.30 m3·m-2·d-1，反应器的反硝化速率与进水硝态氮负荷线性相关（R2=0.937），而硝态氮负荷对出水的COD浓度未发生明显影响；维持进水硝态氮负荷不高于0.16 kg·m-2·d-1，可保证反应器出水的硝态氮与亚硝态氮浓度满足国家标准。通过扫描电镜照片可以看出，PLA/PHBV颗粒表面的生物膜以球菌和杆菌为主，成簇定植在碳源颗粒表面。

Denitrification Performance of a Packed Bed Reactor Using Solid Carbon Source

PLA/PHBV blend, a new kind of biodegradable polymer, was packed into a lab-scale reactor as carbon source and biofilm support. Effects of hydraulic loading and nitrate-nitrogen（NO3^- -N） loading on the denitrification performance of the reactor were investigated. More- over, morphological investigation for biofilm attached on the surface of PLMPHBV particles was carried out by SEM. When hydraulic loading ranged between 1.71 and 8.39 m3· m-2· d-1 with around 100 mg· L-1 of influent NO3- -N, the denitrification rate increased firstly, then dropped with the increase in hydraulic loading, with a maximum value of 40.53 mgNO3- -N· L-1 ·h-1. NO3- -N concentrations in the effluent increased gradually with the increase in hydraulic loading, but COD concentrations decreased gradually. NO2- -N started to accumulate when hydraulic loading was over 3.54 m3. m-2· d-1. NO3- -N and NO2-N concentrations in the effluent could meet the drinking water standard of China when hydraulic loading was lower than 3.54 m3· m-2· d-1. Denitrification rate was linear correlation（R2=0.937） with the influent nitrate loading when hydraulic loading was 5.30 m3·m-2·d-1. NO3 - -N and NO2 - -N concentrations in the effluent could meet the drinking water standard of China when influent NO3- -N loading was not more than O. 16 kg· m-2· d-1. NO3- -N loading had little effect on COD concentrations in the effluent. SEM micrographs from biofilm samples showed two different morphologies（rods and cocci） colonizing the packing material in clusters.