Aiming at the problem of highly toxic Nitrogenous disinfection by-products (N-
DBPs) produced by disinfection in the process of
drinking water, two-point influent activated
carbon-
quartz sand biofilter, activated
carbon-
quartz sand biofilter, and
quartz sand biofilter are selected. This study takes typical N-
DBPs Dichloroacetonitrile (DCAN) as the research object and
aromatic amino acid Tyrosine (Tyr), an important precursor of DCAN, as the model precursor. By measuring the changes of conventional
pollutants in different biofilters, and the changes of Tyr, the output DCAN formation potential of the biofilters, this article investigates the control of DCAN generation of the two-point influent activated
carbon-
quartz sand biofilter. The results show that the average Tyr removal rate of the three biofilters during steady operation is 73%, 50%, and 20%, respectively, while the average effluent DCAN generation potential removal rate is 78%, 52%, and 23%, respectively. The two-point influent activated
carbon-
sand biofilter features the highest removal rate. The two-point water intake improves the
hypoxia problem of the lower filter material of the activated
carbon-
quartz sand biofilter, and at the same time, the soluble microbial products produced by microbial metabolism can be reduced by an appropriate
carbon sand ratio, which is better than traditional
quartz sand filters and activated
carbon-
quartz sand biofilters in the performance of controlling the precursors of N-
DBPs.