Influent:Single Household Wastewater
Denitrification system:Sulfur-driven autotrophic denitrification
Denitrifying reactor:Packed-bed
Medium:Charcoal particles
Culture taken from:nan
Organism (s) cultured:nan
Respiration:Aerobic
Electron donor:Sulfur-limestone
Electron acceptor:Nitrate
Input NO3-N (mg/l):nan
Nitrate removal rate (mg NO3-N/l/h):17–25
Denitrification rate (gNO3-N removed/m3/day):nan
Microorganisms identified:nan
Molecular tools:nan
Major findings:A simple and cost effective treatment techniques was developed based on autotrophic denitrification using sulfur. Their choice of electron donor and pH adjustment is readily available making setup of such a system applicable even in the rural areas. They found that using limestone results in the production of CaSO4- which tends to clogg the pipes. They suggested that for further research one ought to look at replacing limestone with NaOH to adjust the pH.
Authors:Kuai and Verstraete, 1999
Title:Autotrophic Denitrification with Elemental Sulphur in Small-Scale Wastewater Treatment Facilities
Pubmed link:None
Full research link:Link
Abstract:An autotrophic denitrification process with elemental sulphur to achieve a high quality effluent with a low concentration of total N was tested at laboratory scale. Two types of wastewater were tested during a period of 10 months. One was a multiple household wastewater obtained from a municipal wastewater treatment plant and the other was a single household wastewater collected from a family. The wastewaters were first treated by primary sedimentation, followed by nitrifying trickling filtration. The nitrified effluents from the trickling filter were further denitrified in an autotrophic denitrification stage. The autotrophic denitrifying reactor was filled with a mixture of elemental sulphur powder and small pieces of limestone. Sulphur was used as an electron donor and CaCO3 in the limestone served as pH buffer. With a hydraulic retention time of 2–3 hours, up to 86 % of total oxidizable nitrogen (TON) was removed from the multiple household wastewater and 75 % from the single household wastewater. The total N concentration in the final effluents was 3 mg l?1 for the multiple household wastewater and 17 mg l?1 for the single household wastewater. Besides the high removal efficiency and the short hydraulic retention time, other advantages were also noted such as no specific need for inoculum, rapid start up, a wide temperature range for application and low technical labour requirement. Hence, autotrophic denitrification offers interesting potential for removing surplus nitrate from nitrified domestic wastewater particularly in small-scale wastewater treatment facilities.