Cultivation and Resistance to Impact Load Analysis of Different Types of Anaerobic Granular Sludge During the Treatment of Simulated Wastewater

Abstract

In this study, polyvinyl alcohol (PVA), granular active carbon (AC), and Ca²⁺/polyacrylamide (PAM) were used to enhance granulation in three upflow anaerobic sludge blanket (UASB) reactors, UASB-PVA, UASB-AC, and UASB-PAM. The experimental results showed that the start-up of the UASB-PVA reactor was the fastest, UASB-PVA, UASB-AC, and UASB-PAM took 44, 48 and 54 d, respectively, and the performance of UASB-PVA was relatively stable and less fluctuating. When organic load was up to ∼13 kg chemical oxygen demand (COD)/(m³·d), biogas production of PVA sludge, AC sludge, and PAM sludge were 19.10, 12.32, and 15.13 L/d, respectively, and the biogas production of the three reactors was: UASB-PVA>UASB-PAM>UASB-AC. After 128 days of operation, the granulation effect of the sludge from the three reactors was ranked from high to low in the following order: UASB-PVA>UASB-AC>UASB-PAM. In the process of load shock, the COD removal efficiency (CODRE) and ${NH}_4^{+}$ -N removal efficiency ( ${NH}_4^{+}$ -NRE) of the UASB-PVA was the most stable under different load impacts, the standard deviation of CODRE and ${NH}_4^{+}$ -NRE were 2.7% and 8.7%, respectively. The total fluorescence intensity of dissolved organic matter in the effluent of UASB-PVA, AC, and PAM were 2.5 × 10⁵ – 5.5 × 10⁵, 1.8 × 10⁵ – 13.2 × 10⁵, and 1.5 × 10⁵ – 11.5 × 10⁵, respectively. The change range of the total fluorescence intensity of UASB-PVA was the minimal under load impact. The UASB-PVA can play an important role in the upgrading of sewage treatment plants.