Liu Yingjiu

Nitrogen removal efficiency and microbial community analysis of ANAMMOX biofilter at ambient temperature

An upflow anaerobic biofilter (AF) was developed to investigate anaerobic ammonium-oxidizing (ANAMMOX) efficiency in treating low-strength wastewater at ambient temperature (15.3-23.2 °C). Denaturing gradient gel electrophoresis (DGGE) and fluorescence in situ hybridization were used to investigate treatment effects on the microbial community. Stepwise decreases in influent ammonia concentration could help ANAMMOX bacteria selectively acclimate to low-ammonia conditions. With an influent ammonia concentration of 46.5 mg/L, the AF reactor obtained an average nitrogen removal rate of 2.26 kg/(m³ day), and a removal efficiency of 75.9%. polymerase chain reaction-DGGE results showed that microbial diversity in the low matrix was greater than in the high matrix. Microbial community structures changed when the influent ammonia concentration decreased. The genus of functional ANAMMOX bacteria was Candidatus Kuenenia stuttgartiensis, which remained stationary across study phases. Visual observation revealed that the relative proportions of ANAMMOX bacteria decreased from 41.6 to 36.3% across three study phases. The AF bioreactor successfully maintained high activity due to the ANAMMOX bacteria adaptation to low temperature and substrate conditions.

Engineering practicing on dyeing and printing wastewater treatment by multi-methods of catalytic oxidation- anaerobic-MBR

The multi-methods of catalytic oxidation- anaerobic-MBR has been applied to treatment a dyeing and printing wastewater on a engineering after anglicizing characteristics of the wastewater quality. It has been proved by actual operation that the method is a simple and effective with cost low, stable operation, simple maintenance and significant effectiveness for dyeing and printing wastewater treatment.

Experimental study of bio-sorption on Pb 2+ by Chlorella

Bio-sorption of Pb2+ ion from wastewater with Chlorella was investigated in the batch mode. The influence of pH of the solution, biosorbents dose, concentration of ions and contact time on bio-sorption capacity of Pb2+ ions was studied. The studies revealed that Pb2+ ions uptake rate was rather slow, with 75% of the total amount occurring in the first 10min for Chlorella. The optimum pH for bio-sorption of Pb2+ ions was found to be about 5.5. The maximum percent removal was observed at biosorbent dose 1.0g/L; uptake capacity was decreased with increase in concentration of Pb2+. It also showed that factors affecting adsorption from strong to weak were biosorbents dose, pH, contact time and Pb2+ initial concentration; under the optimal conditions, the removal of Pb2+ was 94%.