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 341
- Downloads 0
Sulfation of metal-organic framework (MOF) nanocatalyst for esterification of oleic acid with methanol to produce biodiesel
Background: Metal-organic frameworks (MOFs) represent tremendous potential as heterogeneous catalyst in renewable energy production. In this study, biodiesel production using the modified MOF nanocatalyst was investiga...
Optimization and evaluation of the process variable’s effect on color and turbidity removal from coffee processing wastewater: Using a photoelectrochemical oxidation process
Background: Coffee is the foundation of Ethiopia’s economy, but the wastewater generated by coffee processing cannot be properly treated, therefore, causing various environmental problems. Methods: In this research, el...
Bioremediation of phenanthrene-polluted soil using Bacillus kochii AHV-KH14 as a halo-tolerant strain isolated from compost
Background: Phenanthrene (PHE) is a polycyclic aromatic hydrocarbon (PAH) with crystalline structure of C14H10, which was produced from incomplete combustion of hydrocarbons and fossil fuels and can cause harmful biolo...
The inert surface contamination of SARS-CoV-2 and the effect of disinfectants in one of the specialized and main responsible hospitals for COVID-19 patients in Ahvaz, Iran
Background: SARS-CoV-2, the causative agent of the COVID-19 pandemic, spreads through both direct and indirect pathways. Among the latter, surface contamination is a significant concern due to the virus’s prolonged via...
Contamination and risk assessment of heavy metals in water and fish obtained in Bunza River in Kebbi State, Nigeria
Background: Fish are consumed worldwide due to their nutritional and health benefits; however, heavy metal pollution is compromising their safety. This study aimed to determine heavy metal safety in water and fish, spe...