芦竹固相反硝化反应器脱氮效能及去除尾水邻苯二甲酸二丁酯的研究

Study on Nitrogen Removal and Dibutyl Phthalat Removal Efficiency of Wastewater Treatment Effluent in Arundo donax Solid-Phase Denitrification Reactor

邻苯二甲酸酯(phthalate esters,PAEs)类污染物不可避免地共存于污水厂尾水,其中邻苯二甲酸二丁酯(dibutyl phthalate,DBP)是尾水中毒性和浓度较高的一类PAEs。目前固相反硝化技术被广泛应用于污水厂尾水深度脱氮,本研究构建了以芦竹为植物碳源的固相反硝化反应器,探究了反应器的尾水脱氮和DBP去除效能。结果表明:①芦竹固相反硝化反应器能有效去除60μg/L DBP。实验组出水浓度为(3.50±0.38)μg/L,去除率为93.67%±0.72%。DBP出水浓度随着反硝化反应器高度的增加而降低,并在330 mm处基本实现对60μg/L DBP的完全去除。②DBP的存在不影响芦竹固相反硝化反应器对NO_(3)^(-)-N和TN的去除效果,实验组NO_(3)^(-)-N和TN出水浓度分别为(2.31±0.29)和(3.51±0.40)mg/L,去除率分别为84.49%±1.99%和79.35%±2.43%。③添加和无添加DBP反应器中,以有机物和氮代谢为主的Proteobacteria、Bacteroidota、Chloroflexi和Firmicutes仍为优势菌门,反硝化菌属(如Rhodocyclaceae、Sphaerotilus、Candidatus_Competibacter及Thauera)为优势菌属,其中编码硝酸盐还原酶的napA基因丰度最高。研究显示,芦竹固相反硝化反应器基本能够完全去除60μg/L DBP,并同时具有良好的反硝化脱氮效能。

Phthalate esters(PAEs)inevitably coexist in the effluent,and dibutyl phthalate(DBP)has greater toxicity and higher concentration than other PAEs in the effluent.Currently,solid-phase denitrification(SPD)has been widely used to improve the nitrogen removal rate from wastewater treatment plant(WWTP)effluent.A solid-phase denitrification reactor using Arundo donax as plant carbon source was built up to study the efficiency of denitrification and dibutyl phthalate removal.The results showed that 60μg/L DBP was effectively removed by the Arundo donax solid-phase denitrification reactor.The effluent DBP concentration of the experimental reactor was(3.50±0.38)μg/L,with a removal rate of 93.67%±0.72%.The effluent DBP concentration decreases with the height of the denitrification reactor,and 60μg/L DBP can be completely removed at a height of 330 mm.DBP had no influence on the removal efficiency of NO_(3)^(-)-N and TN in the experimental reactor.The effluent concentrations of NO_(3)^(-)-N and TN were(2.31±0.29)and(3.51±0.40)mg/L,respectively,and removal rates were 84.49%±1.99% and 79.35%±2.43%,respectively.Proteobacteria,Bacteroidota,Chloroflexi,and Firmicutes,which mainly metabolize organics and nitrogen,are still the dominant bacteria in the reactors with and without DBP.The dominant denitrifying genera were Rhodocyclaceae,Sphaerotilus,Candidatus_Competibacter,and Thauera,among which the napA gene encoding nitrate reductase had the highest abundance.The above results show that the Arundo donax solid-phase denitrification reactor can effectively remove 60μg/L DBP and has a good denitrification efficiency.