Abstract: Taking the polyvinyl alcohol and sodium alginate as embedding agent and the domesticated activated sludge as embedding microbial agent, immobilized microbial granules were prepared with the embedding agent and embedding microbial agent in a ratio of 2∶1. The prepared granules were loaded into a homemade reactor in a filling rate of 20%, and the reactor was used for treating synthetic polluted surface water. The performance of the immobilized microbial granules and their pollutant removal efficiency were investigated. The results showed that the optimum hydraulic retention time (HRT) and influent COD loading rate were 10 h and 1.15-1.85 g·L^-1·d^-1, respectively. At water temperature 25-29 ℃, DO concentration 3-4 mg·L^-1, and HRT 10 h, and when the influent COD and NH₄⁺-N were 70.58-91.76 mg·L^-1 and 13.68-17.82 mg·L^-1, respectively, more than 62.3% of the COD and more than 90.6% of the NH₄⁺-N were removed. It was suggested that the immobilized microbial granules could effectively remove the COD and NH₄⁺-N from polluted surface water.

Key words: barley, phosphorus efficient genotype, root morphology, phosphorus uptake.