Improving AOC degradation rate by intensified biological process in advanced water treatment

The object of is to evaluate assimilable organic carbon（AOC） degradation rate by intensified biological technique in advanced water treatment. By artificially acclimating and cultivating strains attached onto carbon surface, the selected strains can be intensified for their degradation to organic matters. The research indicates that ozonation process increases AOC concentration considerably, however, it is beneficial to microdegradation. Temperature and empty bed contact time （ TEBC ） are two important factors affecting microbiology. From 14 to 27 ℃, intensified biological carbon can remove AOC better compared with granular activated carbon （GAC）. Under identical TERC, intensified technique increases more than 10% AOC reduction.

Immobilization biological activated carbon used in advanced drinking water treatment

Bacteria separated from a mature filter bed of groundwater treatment plants were incubated in a culture media containing iron and manganese. A consortium of 5 strains of bacteria removing iron and manganese were obtained by repeated enrichment culturing. It was shown from the experiments of effect factors that ironmanganese removal bacteria in the euhure media containing both Fe and Mn grew better than in that containing only Fe, however, they were unable to grow in the culture media containing only Mn. When comparing the bacteria biomass in the case ofp （DO） ：2.8 mg/L andp （DO） ：9. 0 mg/L, no significant difference was found. The engineering bacteria removing the organic and the bacteria removing iron and manganese were simuhaneously inoculated into activated carbon reactor to treat the effluent of distribution network. The experimental results showed that by using IBAC （ Immobilization Biological Activated Carbon） treatment, the removal efficiency of iron, manganese and permanganate index was more than 98% , 96% and 55% , respectively. After the influent with turbidity of 1.5 NTU, color of 25 degree and oflbnsive odor was treated, the turbidity and color of effluence were less than 0.5 NTU and 15 degree, respectively, and it was odorless. It is determined that the cooperation function of engineering bacteria and activated carbon achieved advanced drinking water treatment.

Pilot Study on Drinking Water Advanced Treatment by GAC-MF System

The pilot performance of the combined GAC-MF membrane process for drinking water advanced treatment was described. In the process of GAC adsorption, under the conditions of 20 min HRT and 6 m/h filtration rate, the removal efficiencies of UV_(254) and trichloromethane could reach 40% and 50% respectively and the UV_(254) and trichloromethane in system effluent was less than 0.015 cm^(-1) and 5μg/L respectively. In the post MF membrane process, MF membrane effectively retained the particles and bacteria in raw water. The effluent turbidity was less than 0.2 NTU and no bacteria were detected at all in permeate. A computer-controlled system was employed to control this system. The membrane operating parameters of backwash interval, duration and flux were studied. The backwash interval of 10-min, 20-min and 60-min was researched respectively, and the variation of trans-membrane pressure was also analyzed. Consequently short backwash interval was recommended under the same water consume.

Novel FGBAC reactor for controlling the leakage of microfauna in drinking water treatment

In order to reduce the microfauna leakage risk from a granular biological activated carbon （GBAC） reactor which employs granular activated carbon （GAC） as adsorption media in drinking water advanced treatment, a novel fiber and granular biological activated carbon （FGBAC） reactor which employs both GAC and activated carbon fiber （ACF） as adsorption media, was developed. The results showed that the species composition of microfauna leaking from FGBAC reactor is almost similar to that leaking from GBAC reactor, however the densities of microfauna leaking from FGBAC reactor is reduced by 26%-81% compared to those leaking from GBAC reactor. In addition, compared to GBAC reactor, FGBAC reactor can increase the removal efflciencies of chemical oxygen demand （COD） and turbidity by 7% and 10%, respectively, during the stable operation period of reactor.