Autotrophic denitrification of synthetic nitrate-contaminated groundwater in up-flow fixed-bed bioreactor by pumice as porous media
Journal Title: Environmental Health Engineering and Management Journal - Year 2018, Vol 5, Issue 3
Abstract
Background: Increasing nitrate concentrations in groundwater resources is considered a common environmental and public health problem worldwide. In this research, an autotrophic up-flow bioreactor with pumice as media was used to study the effects of the sulfur-to-nitrogen (S/N) ratio and empty bed contact time (EBCT) on nitrate removal efficiency and byproducts. Methods: Experiments were carried out in a 3.47 L up-flow, fixed-bed reactor with 3 sampling ports. To evaluate the overall impact of S/N ratio and EBCT on the performance of the bioreactor, several phases with different S/N ratios and EBCTs were applied. Results: At a constant S/N ratio of 3.85 g/g, as EBCT decreased from 24 hours to 2 hours, the nitrate removal efficiency decreased from 98% to 64%. On the other hand, at the desired EBCT of 4 hr, as S/N ratio decreased from 3.85 to 1.51 g/g, nitrate removal efficiency was reduced from 85% to 32%. Changing the EBCT and S/N ratio also affected the effluent nitrite and sulfate concentrations as byproducts. At the S/N ratio of 3.85 g/g and EBCT of 24 hours, effluent nitrite and sulfate concentrations were 0.1 mg NO2--N/L and 463 mg SO4 2-/L, respectively. Decreasing the S/N ratio to 1.51 g/g and the EBCT to 4 hours caused drastic changes in effluent nitrite and sulfate concentrations. Conclusion: The results indicated that the autotrophic denitrification with thiosulfate as electron donor and pumice as media was feasible and applicable for nitrate contaminated groundwater.
Authors and Affiliations
Masoud Tourang, Behnoush Aminzadeh , Ali Torabian
Keywords
Related Articles
- EP ID EP45353
- DOI 10.15171/EHEM.2018.01
- Views 329
- Downloads 0
Estimation of trace elements in sediments by macroalgae: A case study in the northern coast of the Persian Gulf (Bushehr province)
Background: The present study was conducted to investigate the northern coast of the Persian Gulf (Bushehr province), which is exposed to industrial, agricultural, shipping, and oil pollution. This study aimed to deter...
Microbiological contamination of commercial enteral feeding and blenderized tube feeding: A systematic review
Background: All types of enteral feeding (EF) formulations, whether blenderized tube feeding (BTF) at hospital kitchen, or commercial enteral feeding (CEF), contains nutrients. The nature of these foods (in terms of pH...
Metal exposure and breast malignancy: A case-control study of Malwa Region of Punjab
Background: Breast cancer is triggered by uncontrollable breast cell development. These metals may build up in human serum and tissues, causing estrogenic/malignant consequences. Therefore, metals are being studied to...
Sulfur dioxide emissions in Iran and environmental impacts of sulfur recovery plant in Tabriz Oil Refinery
Background: Combustion of fossil fuels contributes to sulfur dioxide (SO2) emissions. To deal with this issue, the government of Iran has appointed the oil refineries to upgrade their installations and produce high quali...
Effect of hydrocarbonic pollutants on the stability and soil water repellency intensity: A case study in Bandar Abbas Oil Refinery, Hormozgan province, Iran
Background: The contamination of soil and water with hydrocarbonic pollutants is a major environmental problem. Soil water repellency will interrupt water infiltration, and may decline plant growth and potentially trigge...