Abstract To achieve stable partial nitrification, activated sludge from a wastewater treatment plant using free ammonia (FA) inhibition was immobilized in a polyvinyl alcohol carrier. After FA treatment at 16.44 mg L−1 for 1 day, due to the increased growth rate gap between ammonium-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB), AOB enrichment and NOB inhibition were achieved within 12 days, with AOB and NOB accounting for 65.61 and 0.05%, respectively. Subsequently, with dissolved oxygen concentrations of 4−5 mg L−1, pH of 7.6–7.8 and temperature of 25 ± 1 °C, the immobilized carrier made of activated sludge achieved more than 90% and more than 86% of nitrite accumulation rate at the influent ammonia concentration of 90−110 mg L−1 and 35−50 mg L−1, respectively. After 50 days operation, the NOB content was 0.10%, indicating the immobilized carrier provided favorable conditions for maintaining the low NOB content. Furthermore, due to the low NOB content in the inoculum and the oxygen-limited environment formed by the increase in the AOB numbers in the carrier, immobilized carrier with different initial biomass (1, 2.5 and 5%) can achieve stable partial nitrification.

中文翻译：

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游离氨处理下的活性污泥凝胶固定化不同初始生物量长期部分硝化

摘要 为了实现稳定的部分硝化作用，将使用游离氨 (FA) 抑制剂的废水处理厂的活性污泥固定在聚乙烯醇载体中。在 16.44 mg L−1 FA 处理 1 天后，由于氨氧化细菌 (AOB) 和亚硝酸盐氧化细菌 (NOB) 之间的生长速度差距增加，在 12 天内实现了 AOB 富集和 NOB 抑制，AOB和 NOB 分别占 65.61 和 0.05%。随后，在溶解氧浓度为 4-5 mg L-1、pH 为 7.6-7.8、温度为 25±1 °C 的条件下，由活性污泥制成的固定化载体实现了 90% 以上和 86% 以上的亚硝酸盐积累率进水氨浓度分别为 90-110 mg L-1 和 35-50 mg L-1。运行 50 天后，NOB 含量为 0.10%，表明固定化载体为维持低 NOB 含量提供了有利条件。此外，由于接种物中NOB含量低，载体中AOB数量增加形成的限氧环境，不同初始生物量（1%、2.5%和5%）的固定化载体可以实现稳定的部分硝化。