含氮杂环化合物吡啶的缺氧降解和毒性削减研究

运用摇瓶试验,研究了含氮杂环化合物吡啶的缺氧降解情况、毒性削减规律以及它们之间的关系。结果表明,在吡啶缺氧降解过程中,有利于废水毒性削减的C／N比为8左右;废水中主要致毒物质为吡啶和亚硝酸盐,且亚硝酸盐的毒性大于吡啶的毒性,两者的联合为毒性相加作用;在整个吡啶降解过程中,废水毒性与吡啶降解和亚硝酸盐的产生有着直接联系,毒性削减时间长短与吡啶初始浓度有关。     

Simultaneous pyridine biodegradation and nitrogen removal in an aerobic granular system

Simultaneous pyridine biodegradation and nitrogen removal were successfully achieved in a sequencing batch reactor(SBR) based on aerobic granules. In a typical SBR cycle, nitritation occurred obviously after the majority of pyridine was removed, while denitrification occurred at early stage of the cycle when oxygen consumption was aggravated. The effect of several key operation parameters, i.e., air flow rate, influent NH_4~+-N concentration,influent p H and pyridine concentration, on nitritation, pyridine degradation and total nitrogen(TN) removal, was systematically investigated. The results indicated that high air flow rate had a positive effect on both pyridine degradation and nitritation but a negative impact of overhigh air flow rate. With the increase of NH_4~+ dosage, both nitritation and TN removal could be severely inhibited. Slightly alkaline condition, i.e., pH 7.0–8.0, was beneficial for both pyridine degradation and nitritation. High pyridine dosage often resulted in the delay of both pyridine degradation and nitritation. Besides, extracellular polymeric substances production was affected by air flow rate, NH_4~+ dosage, pyridine dosage and p H.In addition, high-throughput sequencing analysis demonstrated that Bdellovibrio and Paracoccus were the dominant species in the aerobic granulation system. Coexistence of pyridine degrader, nitrification related species, denitrification related species, polymeric substances producer and self-aggregation related species was also confirmed by highthroughput sequencing.     

影响顶空-气相色谱法测定水中吡啶准确度的关键因素探讨

通过试验,讨论盐析效应、顶空的平衡温度和平衡时间、水样的p H值、色谱条件等对顶空-气相色谱法测定环境水体中吡啶准确度的影响。优化上述条件后,方法在0 mg/L~3.95 mg/L范围内线性良好,检出限可达0.016 mg/L,测定下限为0.064 mg/L。用该方法对地表水和生活污水做3个质量浓度水平的加标回收试验,测定6次结果的RSD为1.7%~5.7%,回收率为93.9%~113%。