ABSTRACT

In this study, four sulphur-based carriers (C1–C4) which have different mass ratio of sodium silicate to carrier from 30% to 50% (C1–C3) and the existence of water (C4) were prepared in order to evaluate the effect of the different physical properties on denitrification in sulphur-based autotrophic processes. While the apparent density and the compressive strength decreased as the proportion of sodium silicate increased and water was added in the carriers, the average pore size and the porosity increased from 0.43 to 3.13 µm and from 38% to 67%, respectively. The treatment system using the carrier C4 with the highest surface area was stabilized most rapidly and achieved the highest nitrogen removal efficiency of 85.6 ± 5.0% during a relatively short HRT of 3 h. The efficiency of nitrate removal was enhanced by 36.9% due to the increase of the ratio of sodium silicate in the carriers from C1 to C3, and more 4.8% point of removal rate increased in the carrier C4 by adding water to the carrier C3. The sum of Thiobacillus and Sulfurimonas was obtained up to 65.90% among the microbial community in the carrier C4 which has the highest distribution (38.35%) of pore size above 20 µm considered to be favourable for retaining autotrophic denitrifiers. From the above results, it is obvious that the physical properties of the sulphur-based carrier and its ability of denitrification can be influenced significantly by the composition of the carrier.

摘要

在这项研究中，制备了四种硫基载体（C1-C4），其硅酸钠与载体的质量比从 30% 到 50%（C1-C3）不同，并且存在水（C4），以评估不同物理性质对硫基自养过程中反硝化作用的影响。随着载体中硅酸钠比例的增加和水的添加，表观密度和抗压强度降低，平均孔径和孔隙率分别从 0.43 增加到 3.13 µm，从 38% 增加到 67%。使用表面积最大的载体 C4 的处理系统稳定最快，在相对较短的 3 小时 HRT 期间实现了 85.6 ± 5.0% 的最高脱氮效率。硝酸盐去除效率提高了 36。9％是由于载体中硅酸钠的比例从C1增加到C3，并且通过向载体C3中加水在载体C4中去除率增加了4.8％。总数是在载体 C4 的微生物群落中，硫杆菌和硫单胞菌的含量高达 65.90%，其孔径大于 20 µm 的分布最高 (38.35%)，被认为有利于保留自养反硝化菌。从以上结果可以明显看出，硫基载体的物理性质及其反硝化能力会受到载体组成的显着影响。