蛋壳微载体对硝化颗粒污泥快速培养的影响

Effects of eggshell microcarriers on the rapid cultivation of nitrifying granular sludge

采用连续流气提内循环反应器,考察了投加蛋壳微载体对硝化颗粒污泥快速培养的影响特性.结果表明,投加0.5g/L蛋壳微载体(75μm)的反应器(R2)1个月内实现污泥颗粒化,比对照组(R1)提前1~2周,且R2所得颗粒污泥表现出更高的混合液挥发性悬浮固体浓度(MLVSS)(R1=1.7g/L、R2=2.2g/L)、紧密结合型胞外聚合物(TB-EPS)含量(R1=97.65mg/gVSS、R2=136.29mg/gVSS)及TB-PN/PS比值(R1=2.95、R2=4.73),以及更好的沉降性能(R1、R2的SVI_(3)和SVI_(30)分别为41.67,37.5mL/g,30.36,28.57mL/g).与R1相比,R2中颗粒污泥具有更高活性,比耗氧速率(SOUR)和比氨氧化速率(SAOR)分别为754mgO_(2)/(gVSS·h)和90.74mg/(gVSS·h).高通量测序结果表明,投加蛋壳微载体的颗粒污泥中富集了更高丰度的硝化菌(Nitrosomonas)以及EPS产生菌(如Comamonadaceae__unclassified)等.

The influence of adding eggshell microcarriers on the rapid cultivation of nitrifying granular sludge was investigated in a continuous flow gas-lift internal circulation reactor.The results showed that the reactor(R2)with the addition of 0.5g/L eggshell microcarriers(75μm)achieved sludge granulation within one month,which was 1~2weeks earlier compared to the control(R1).Furthermore,the resulting granular sludge in R2 exhibited higher mixed liquor volatile suspended solids(MLVSS)(R1=1.7g/L,R2=2.2g/L),Tightly Bound-EPS(TB-EPS)content(R1=97.65mg/gVSS,R2=136.29mg/gVSS),TB-PN/PS ratio(R1=2.95,R2=4.73),and better settling performance(with respective SVI_(3)and SVI_(30)values of 41.67,37.5mL/g for R1,and 30.36,28.57mL/g for R2).Compared to R1,the granular sludge in R2had higher activity,with specific oxygen uptake rate(SOUR)and specific ammonia oxidation rate(SAOR)values of 754mgO_(2)/(gVSS·h)and 90.74mg/(gVSS·h),respectively.High-throughput sequencing results indicated that the granular sludge supplemented with eggshell microcarriers had a higher abundance of nitrifying bacteria(Nitrosomonas)and EPS-producing bacteria(such as Comamonadaceae__unclassified).