Anaerobic Digestion of Wastewater With High Sulfate Concentration Using Micro-Aeration and Natural Zeolites

Abstract

-The behavior of anaerobic digestion in batch and UASB reactors using a microaerobic process and natural zeolites was studied. Laboratory assays were carried out across 4 sets of variables: different COD/SO 4 2-ratios, different airflow levels, with and without natural zeolites and room and mesophilic controlled temperatures. The microaerobic process demonstrated hydrogen sulfide removal levels exceeding 90% in most cases, while maintaining the flammable condition of the generated biogas. The level of COD removal exceeded 75% in UASB reactors despite their operation under very low hydraulic retention times (2.8-4.8 hours). The effectiveness of natural zeolites in accelerating UASB reactor startup was demonstrated.Results showing the positive influence of zeolites on the granulation process in UASB reactors were also achieved.

Advances in the biological removal of sulphides from aqueous phase in anaerobic processes: A review

“…The resulting H 2 S concentration was very close to zero most of the time (more than 98 % H 2 S removal was achieved). Montalvo et al (2014a) used natural zeolite in a microaerobic procedure (0.08 ppmv) into a UASB reactor. They found that the use of natural zeolite helped the granulation process and start up of the UASB reactor; with zeolite there was a time decrease of 50% to complete the granulation compared to that of the UASB reactor without zeolite.…”