磷酸化对包埋 anammox 污泥的聚乙烯醇/海藻酸盐凝胶特性的影响

Polyvinyl alcohol/sodium alginate (PVA/SA) gel embedding is one of the effective approaches to address the issues of easy loss and high susceptibility to external environmental disturbances in anaerobic ammonia oxidation (anammox) bacteria. However, its application is limited by poor mass transfer performance and low mechanical strength. This study proposes a method to enhance the properties of PVA/SA hydrogels through phosphorylation treatment. The results indicate that the optimal phosphorylation conditions are as follows: phosphorylation reagent K₃PO₄, phosphorus concentration of 50 mg·L⁻¹, and treatment duration of 30 min. Under these optimal conditions, the mass transfer efficiencies of the gel for ammonia nitrogen, nitrite nitrogen, and Rhodamine B increased by 28.6%, 64.4%, and 32.3%, respectively; the mechanical strength increased by 1.75 times; and swelling decreased by 17.0%. The mechanism behind the performance improvement is attributed to the reaction between phosphate and PVA/SA, where high-molecular-weight alginate chains are replaced by low-molecular-weight phosphate groups, significantly enhancing the gel's pore structure. The anammox sludge activity embedded in phosphorylated gel was 58.1% higher than that in non-phosphorylated gel. Therefore, this research provides a feasible solution to key challenges in anammox sludge immobilization technology and holds promise for promoting the engineering application of the anammox process.