Addition of sodium alginate as a nucleus shortens granulation of aerobic sludge

Abstract

To date, only a handful of studies have described application of organic materials as carriers (nuclei) in the aerobic granular sludge (AGS) system, compared to inorganic materials.

Rapid Formation and Performance of Aerobic Granular Sludge Driven by a Sodium Alginate Nucleus under Different Organic Loading Rates and C/N Ratios

“…The SAN was prepared by cross-linking a CaCl 2 solution (20 g/L) and SA (20 g/L, chemically pure, Xilong Scientific, Shantou, China). A magnetic agitator (78-1, Dingxinyi Instrument, Shenzhen, China) was used to complete the cross-linking reaction (see the previous study [13] for details). A SAN with a certain mechanical strength and a spherical shape was prepared through the hydraulic shear force generated by the liquid-swirling flow.…”

“…Flocculent sludge with poor settling performance was removed during the setting phase. In addition, the dosage of the SAN was controlled at 0.06 g/L, as reported previously [13].…”

“…Flocculent sludge with poor se ling performance was removed during the se ing phase. In addition, the dosage of the SAN was controlled at 0.06 g/L, as reported previously [13]. In phase 2 (P2), four groups of reactors (P2-R1, P2-R2, P2-R3, and P2-R4) with different C/N ratios were designed.…”

“…This suggests its potential use as a nucleation site for sludge formation and microbial attachment to facilitate the development of granular sludge structures [12]. In our previous study [13], the rapid formation of AGS was realized through the preparation of a sodium alginate nucleus (SAN), which resulted in the formed AGS having good sedimentation performance and pollutant removal ability. However, that study mainly focused on the feasibility and mechanism of a SAN to cultivate AGS, ignoring the influence of operational parameters on the formation and performance of AGS, which is the focus of this study.…”

“…In the present study, different OLRs and C/N ratios were designed, and then their effect on the rapid formation of AGS in a SAN system was explored. Based on the previous study [13], the optimal dosage of the SAN was put in a sequencing batch reactor (SBR), followed by monitoring the properties and performance of AGS, including the granular morphological structure, EPS content, and water quality. To better realize practical applications, the recovery efficiency of sodium alginate (SA) was also analyzed.…”