[A new discovery of anaerobic sludge granular with big aera minerals core].

A anaerobic sludge granular containing mineral core with a diameter of 1mm was discovered in lab scale expanded granular sludge bed (EGSB) reactor operated only with glucose as substrate. By SEM, the granular was a core packed by compact bacterium, in which minerals distribute equally and there are caves caused by biological self-degradation. By energy spectrum and X-ray, the core is composed of Ca5 (PO4 x CO3)3 (OH). On the basis of its construction characteristics, the developing mechanism was investigated as well as the developing model of the sludge granular was present, the results shown that the contributing factors influencing mineral core formation are external and internal pH value of sludge granular.