NOB suppression in pilot-scale mainstream nitritation-denitritation system coupled with MBR for municipal wastewater treatment

Emerging biological processes for municipal wastewater treatment

“…In practice, a single parameter-based control strategy was demonstrated to be unable to sustain the effective suppression of NOB against AOB. In this regard, Wang et al (2019) reported a holistic operation strategy by synergetic control of DO, SRT and sludge return ratio. As a result, successful suppression of NOB was achieved with a nitrite accumulation rate of more than 80% in a pilot step-feed plant with a treatment capacity of 30 m 3 real municipal wastewater per day.…”

Perspectives and actions moving forward

“…In such a single-stage system, process design and operation strategies for nitrite oxidizing bacteria (NOB) repression are critical, without compromising ammonia oxidizing bacteria (AOB) and anammox activities. It has been reported that a short sludge retention time (SRT) favours NOB washout and the establishment of nitrite shunt (Wang et al, 2019;Xu et al, 2017). Therefore, separating the SRT of suspended nitrifying sludge and fixed-growth anammox bacteria (i.e.…”

“…Due to the low concentration of ammonium in municipal wastewater, FA and FNA inhibition are no longer available, while single parameter control appears ineffective for NOB repression; see, for example, the unsuccessful NOB repression with low DO concentration control (Lotti et al, 2015). It has been reported that the combined control of SRT, alternating anoxic/oxic conditions, sludge return ratio and DO concentration appeared to be effective for NOB repression in a pilot-scale step-feed reactor (Wang et al, 2019). This indicates that synergistic control of multi-parameters could offer an engineering solution towards stable mainstream deammonification, while further investigation is definitely needed.…”

Research of performance characteristics of membrane modules for wastewater treatment

“…Это достигается благодаря увеличению времени обработки (в зарубежной литературе используется термин hydraulic retention time) и доз ила, что ведет к увеличению объема сооружений. Снижение объема сооружений в настоящее время принято осуществлять с применением мембранных биореакторов -илоразделение происходит не во вторичном отстойнике, а с применением мембранных методов и технологий [2].…”

“…It's attainable by increasing the treatment time (the term "hydraulic retention time" is in use in the international literature) and the content of mixed liquor suspended solids (MLSS) which cause the size of wastewater treatment facilities to go up. Presently the size of these structures can be reduced if membrane bioreactors are used, as in this case membrane methods and technologies are applied to separate the sludge, and this process does not need a secondary settling tank [2].…”