S47 Study on Anaerobic Ammoniumoxidation (ANAMMOX) Sludge Immobilized in Different Gel Carriers and Its Nitrogen Removal Performance

Abstract

To maintain Anammox biomass, different materials were used as carriers to immobilize Anammox sludge. The adsorptive property, anaerobic ammonia oxidation activity, and stability of the particles were evaluated. The results indicated waterborne polyurethane (WPU) was the most suitable immobilizing material. In a continuous flow experiment, we further investigated the resistance to impact load and the anaerobic ammonia oxidation activity by increasing the influent load. It was found that for WPUimmobilized particles, no effluent SS or particles fracture was observed during the 66-day operation, and the WPU-immobilized particles showed a strong capability to retain sludge and good stability in the long-term.

Research advances and challenges in anammox immobilization for autotrophic nitrogen removal

“…Natural polymeric gels degrade easily whereas synthetic gels have the problem of swelling or expansion. Swelling is measured in terms of an expansion coefficient, the ratio of the mean diameter of the immobilized gels after 72 h of treatment (20 immobilized gels slowly shaken in 400 mL of deionized water) to the mean diameter of the original immobilized gels . The swelling of polymeric gels can be counteracted by the addition of polymerizing agent .…”

“…Initially, the mechanical stability was determined by compression test (a 2000 N load cell with a constant speed of 3 × 10 −5 m s −1 at room temperature) and tensile test (pulled with a constant speed 2.1 × l0 −5 m s −1 at room temperature . Recently, a mixture of 30 immobilized gels in 400 mL deionized water was magnetically stirred at 500–600 rpm for 24–48 h, after which the mechanical stability was determined by ratio of intact immobilized gels to the original number of immobilized gels …”

“…31 Recently, a mixture of 30 immobilized gels in 400 mL deionized water was magnetically stirred at 500-600 rpm for 24-48 h, after which the mechanical stability was determined by ratio of intact immobilized gels to the original number of immobilized gels. 33,37 .…”

“…Swelling is measured in terms of an expansion coefficient, the ratio of the mean diameter of the immobilized gels after 72 h of treatment (20 immobilized gels slowly shaken in 400 mL of deionized water) to the mean diameter of the original immobilized gels. 37 The swelling of polymeric gels can be counteracted by the addition of polymerizing agent. 41,61 The order of expansion coefficient in synthetic polymers was found by Chen et al 37 to be WPU > PEG > PVA > CMC.…”

“…37 The swelling of polymeric gels can be counteracted by the addition of polymerizing agent. 41,61 The order of expansion coefficient in synthetic polymers was found by Chen et al 37 to be WPU > PEG > PVA > CMC.…”