低碳源条件下BSBR工艺磷酸盐强化吸收影响因素分析

相较于传统强化生物除磷工艺通过测流实现污泥磷酸盐的富集和回收,生物膜法可对废水中的磷酸盐进行高效同步去除和富集,具有应用潜力。针对生物膜法厌氧释磷需要高碳源刺激的问题,通过优化工艺条件强化生物膜好氧吸磷能力提高生物膜蓄磷量,进而减少厌氧释磷时的碳源消耗。采用生物膜法序批式反应器(BSBR),考察了在低碳源投加下,蓄磷量与磷富集罐磷浓度的响应关系,采用正交试验探究溶解氧、搅拌速度以及好氧时间对磷酸盐强化吸收的影响。结果表明:当温度为(25±2)℃、厌氧外加碳源为(180±20) mg/L时,富集罐磷浓度随着生物膜蓄磷量的增加而增加,最高可达到90.62 mg/L。相同蓄磷量下,溶解氧浓度从2 mg/L增加至8 mg/L,磷酸盐最大吸收速率可从2.60 mg/(L·h)上升到8.70 mg/(L·h)。正交实验结果表明:各因素对磷酸盐强化吸收的影响顺序为溶解氧>好氧时间>搅拌速度。当溶解氧浓度为6 mg/L,搅拌速度为200 r/min,好氧时间为5 h时,除磷效率最高可达99.98%。

ANALYSIS OF INFLUENCING FACTORS OF PHOSPHATE ENHANCED ABSORPTION IN BSBR PROCESS UNDER LOW CARBON SOURCE CONDITIONS

Compared with the traditional enhanced biological phosphorus removal(EBPR) process which achieves the enrichment and recovery of sludge phosphate through the flow process, the biofilm process can efficiently and synchronically remove and enrich phosphate in wastewater, thus has the potential to be applied to the mainstream process. Given the problem of high carbon source stimulation required for anaerobic phosphorus release by the biofilm process, the phosphorus storage of biofilm can be enhanced by optimizing the process conditions to strengthen the biofilm aerobic phosphorus uptake capacity, thus reducing the consumption of carbon source during anaerobic phosphorus release. In this paper, a biofilm sequencing batch reactor(BSBR) was used to investigate the response relationship between phosphorus storage and phosphorus concentration in the recovery tank under the addition of a low carbon source. The effects of dissolved oxygen, mixing strength and aerobic time on phosphate enhanced absorption were studied by orthogonal test. The results showed that when the temperature was(25±2) ℃ and the anaerobic external carbon source was(180±20) mg/L, the phosphorus concentration in the enrichment solution increased with the increase of phosphorus storage in the biofilm, up to 90.62 mg/L. Under the same phosphorus storage, the dissolved oxygen concentration increased from 2 mg/L to 8 mg/L, and the maximum phosphate absorption rate increased from 2.60 mg/(L·h) to 8.70 mg/(L·h). Orthogonal experiments showed that the order of influencing factors on phosphate enhanced absorption was dissolved oxygen>aerobic time>mixing intensity. When the dissolved oxygen concentration was 6 mg/L, the stirring speed was 200 r/min, and the aerobic time was 5 h, the phosphorus removal efficiency was up to 99.98%.