The study revealed the difference in the performance of anaerobic digestion juice in the wastewater of two aerobic processes and its mechanism

Recently, the innovative team of livestock and poultry manure energy utilization and pollution control of the Biogas Science Research Institute of the Ministry of Agriculture and Rural Affairs found the difference in the performance of anaerobic digestive juices of pig farm wastewater by hypoxic aerobic and sequential batch reactor processes, and elaborated on
its mechanism, and the relevant results were published in the Journal of Cleaner Production.

 

The anaerobic-aerobic combination process is the mainstream process
of wastewater treatment for large-scale pig farms.
Anaerobic digestion (biogas fermentation) technology not only effectively removes organic matter and produces clean energy - biogas, but the anaerobic digestion liquid (also known as biogas slurry) produced by the pig farm wastewater after biogas fermentation treatment still contains higher concentrations of organic matter and is rich in pollutants such as ammonia nitrogen, which needs further treatment
before being discharged into the water body or entering the municipal pipe network.
Sequential batch reactor and hypoxic aerobic process are the main processes for aerobic post-treatment of anaerobic digestion juice in pig
farms.
However, the treatment performance of these two processes is still unclear
.

 

Based on the anaerobic-plus raw water-batch aeration process proposed in the early stage of research and development, the team researchers further explored the difference in treatment performance and its mechanism
between the two processes.
It is found that when the proportion of raw water addition is less than 30%, the removal performance of ammonia nitrogen and total nitrogen by the hypoxic aerobic process is better than that of the sequential batch reactor process, and the removal performance of ammonia nitrogen and total nitrogen by the sequential batch reactor process is better than that of the hypoxic aerobic process
after the raw water addition ratio reaches 30%.
The main reason for this difference is that the concentration of easily degradable organic matter and the reflux ratio of the mixture in the denitrification stage are different, resulting in differences in reaction kinetics, and the ammonia oxidation activity and anaerobic oxidation activity of the sludge in the sequential batch reactor process are high, while the denitrification activity of the sludge in the hypoxic aerobic process is high
.
The research results provide a scientific basis
for the selection of wastewater treatment processes for pig farms.

 

The research was funded
by the National Pig System Project and major scientific and technological projects in Sichuan Province.

 

Original link: https://doi.
org/10.
1016/j.
jclepro.
2022.
133643