School of Civil Engineering, Hefei University of Technology, Hefei, People's Republic of China.
School of Resource and Environmental Engineering, Hefei University of Technology, Hefei, People's Republic of China.
Environ Technol. 2021 Sep;42(21):3379-3389. doi: 10.1080/09593330.2020.1730981. Epub 2020 Feb 28.
The forward osmotic membrane bioreactor (FOMBR) is an emerging innovative technology with broad application prospects in the field of wastewater treatment. Its application is severely limited by concentration polarization, salinity accumulation, and evident water flux decline. Gradual salinity accumulation to a maximum conductivity of 19.7 mS cm under continuous flow operation suppressed the activities of sludge and biodegradation efficiencies. The employment of the regulation of intermittent supernatant discharge was first investigated to alleviate inhibition caused via accumulated salinity in the bioreactor, and bilateral influent was examined with respect to the performance of the FOMBR. The preferable condition to be applied was FO orientation mode (i.e. active layer facing feed) with spacers added to the surface. Given the decreased salt concentration with 2 L of the supernatant removed per day, the water flux declined more slowly and sludge activities were recovered. When compared to the performance without discharging supernatant, the strategy of controlling salinity could improve the removal efficiencies of NH-N, PO-P, and total organic carbon (TOC) by 15.1, 14.3, and 2.3%, respectively. Additionally, the sludge in the intermittent supernatant discharge bioreactor exhibited better sludge property, larger sludge particle size, and recovered sludge activities with the mixed liquid suspended solids (MLSS) stable at around 4.90 g L. Therefore, regulation of intermittent salt discharge and controlling the salinity concentration in bioreactor can be employed as an effective method to deal with concentration polarization and salinity accumulation in the FOMBR.
正向渗透膜生物反应器（FOMBR）是一种新兴的创新技术，在废水处理领域具有广泛的应用前景。其应用受到浓差极化、盐度积累和明显水通量下降的严重限制。在连续流动操作下，逐渐积累的盐度将最大电导率抑制到 19.7 mS cm，从而抑制了污泥的活性和生物降解效率。首次研究了间歇性上清液排放的调节来缓解生物反应器中积累的盐分引起的抑制作用，并考察了双侧进水对 FOMBR 性能的影响。优选的应用条件是 FO 取向模式（即活性层朝向进料），并在表面添加间隔物。通过每天去除 2 L 的上清液，可以降低盐度，使水通量下降更慢，污泥活性得到恢复。与不排上清液的性能相比，控制盐度的策略可以分别提高 NH-N、PO-P 和总有机碳（TOC）的去除效率 15.1%、14.3%和 2.3%。此外，在间歇式上清液排放生物反应器中，污泥具有更好的污泥特性、更大的污泥粒径和恢复的污泥活性，混合液悬浮固体（MLSS）稳定在 4.90 g L 左右。因此，间歇式盐排放调节和控制生物反应器中盐度浓度可以作为一种有效方法来解决 FOMBR 中的浓差极化和盐度积累问题。
