Xin Xin, Lu Hang, Yao Li, Leng Lu, Guan Lei
School of Resources and Environment, Chengdu University of Information Technology, Chengdu, 610225, China.
Appl Biochem Biotechnol. 2017 Jan;181(1):424-433. doi: 10.1007/s12010-016-2221-6. Epub 2016 Sep 6.
Based on the principle of self-coagulation of microorganisms, the flocculant-producing denitrifying bacterial TN-14 sludge was added to the continuous-flow reactor for treating domestic sewage. The bacterial TN-14 sludge acted as the main seed sludge to promote the rapid formation of aerobic granular sludge. The sludge morphology, sludge volume index (SVI) values, amounts of extracellular polymeric substances (EPS), and the role of calcium in the granulation process of the sludge were investigated. Results showed that brown aerobic granules with the particle size of 0.5 ~ 2.0 mm was successfully cultivated at 40 days, and its SVI decreased from 122.62 mL g initially to 46.61 mL g and remained at 44.28 ~ 60.51 mL g afterwards. The protein (PN) content in sludge EPS increased from 76.4 mg g initially to 512.3 mg g. Compared with PN, the polysaccharide (PS) content did not change much throughout the operation process of the bioreactor. Energy-dispersive spectrum (EDS) showed that Ca elements were deposited inside the granular sludge, and X-ray diffraction (XRD) showed that Ca elements existed in the granular sludge in the forms of CaCO, KCaPO, CaPO, and CaO(PO). The formation mechanism of continuous-flow aerobic granular sludge was that bacterial TN-14 sludge could promote the EPS content of sludge, and PN content of EPS increases the hydrophobicity and settling performance of the sludge. Calcium mainly exists in the granular sludge in the form of inorganic calcium phosphate, and therefore plays the role of nucleation in sludge granulation.
基于微生物自凝聚原理，将产絮凝剂的反硝化细菌TN-14污泥添加到连续流反应器中处理生活污水。细菌TN-14污泥作为主要的种子污泥，促进了好氧颗粒污泥的快速形成。研究了污泥形态、污泥体积指数（SVI）值、胞外聚合物（EPS）含量以及钙在污泥颗粒化过程中的作用。结果表明，在40天时成功培养出粒径为0.5～2.0mm的棕色好氧颗粒，其SVI从最初的122.62mL/g降至46.61mL/g，之后保持在44.28～60.51mL/g。污泥EPS中的蛋白质（PN）含量从最初的76.4mg/g增加到512.3mg/g。与PN相比，在生物反应器整个运行过程中多糖（PS）含量变化不大。能谱（EDS）显示Ca元素沉积在颗粒污泥内部，X射线衍射（XRD）表明Ca元素以CaCO、KCaPO、CaPO和CaO(PO)的形式存在于颗粒污泥中。连续流好氧颗粒污泥的形成机制是细菌TN-14污泥可促进污泥的EPS含量增加，且EPS中的PN含量提高了污泥的疏水性和沉降性能。钙主要以无机磷酸钙的形式存在于颗粒污泥中，因此在污泥颗粒化过程中起成核作用。
