Mixed cultured algal and bacterial remediation of dissolved organic nitrogen under low solid retention time condition

2018 ◽  
Vol 103 ◽  
pp. 240-247 ◽  
Author(s):  
Swati Sharma ◽  
Halis Simsek
Keyword(s):  
Retention Time ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Solid Retention Time ◽  
Time Condition ◽  
Bacterial Remediation

Impact of solids retention time on dissolved organic nitrogen and its biodegradability in treated wastewater

2016 ◽  
Vol 92 ◽  
pp. 44-51 ◽  
Author(s):  
Halis Simsek ◽  
Murthy Kasi ◽  
Jae-Bom Ohm ◽  
Sudhir Murthy ◽  
Eakalak Khan
Keyword(s):  
Retention Time ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Treated Wastewater ◽  
Solids Retention Time ◽  
Solids Retention

Understanding the formation of recalcitrant dissolved organic nitrogen as a result of thermal hydrolysis and anaerobic digestion of municipal sludge

2021 ◽  
Vol 7 (2) ◽  
pp. 335-345
Author(s):  
Dian Zhang ◽  
Zhaohui An ◽  
Mary Strawn ◽  
Tom Broderick ◽  
Wendell Khunjar ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Retention Time ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Thermal Hydrolysis ◽  
Municipal Sludge ◽  
Solids Retention Time ◽  
Solids Retention ◽  
Different Temperatures ◽  
First Time

This study for the first time investigated the turnover of dissolved organic nitrogen in lab-scale thermal hydrolysis pretreatment at different temperatures with and without mesophilic anaerobic digestion at a solids retention time of 15 days.

The effect of aeration and non-aeration time on simultaneous organic, nitrogen and phosphorus removal using an intermittent aeration membrane bioreactor

2002 ◽  
Vol 46 (9) ◽  
pp. 193-200 ◽  
Author(s):  
Z. Ujang ◽  
M.R. Salim ◽  
S.L. Khor
Keyword(s):  
Removal Efficiency ◽  
Retention Time ◽  
Phosphorus Removal ◽  
Organic Nitrogen ◽  
Membrane Bioreactor ◽  
Synthetic Wastewater ◽  
Intermittent Aeration ◽  
Nitrogen And Phosphorus ◽  
Solid Retention Time ◽  
Aeration Time

A laboratory-scale membrane bioreactor (MBR) was fed with synthetic wastewater to investigate the possibility of simultaneous removal of organic, nitrogen and phosphorus by intermittent aeration. The MBR consists of two compartments using a microfiltration membrane with 0.2 mm pore size and a surface area of 0.35 m2. Hydraulic retention time was set at 24 hours and solid retention time 25 days. MLSS concentration in the reactor was in the range of 2,500-3,800 mg/L. The MLSS internal recycling ratio was maintained at 100% influent flow rate. Intermittent aeration was applied in this study to provide an aerobic-anaerobic cycle. Three stages of operations were conducted to investigate the effect of aeration and non-aeration on simultaneous organic and nutrient removal. In Stage 1, time cycles of aeration and non-aeration were set at 90/150 min and 150/90 min in the first and second compartment, the removal efficiency was 97%, 94% and 70% for COD, nitrogen and phosphorus respectively. In Stage 2, time cycles of aeration and non-aeration were set at 60/120 min and 120/60 min in the first and second compartment, the removal efficiency was 97%, 96% and 71% for COD, nitrogen and phosphorus respectively. In Stage 3, time cycles of aeration and non-aeration were set at 120/120 min and 120/120 min in compartment 1 and 2, the removal efficiency was 98%, 96% and 78% for COD, nitrogen and phosphorus respectively. Results show that longer non-aeration time in the second compartment provided better performances of biological phosphorus removal.

Electro-Oxidation to Convert Dissolved Organic Nitrogen and Soluble Non-Reactive Phosphorus to More Readily Removable and Recoverable Forms

Chemosphere ◽  
2021 ◽  
pp. 130876
Author(s):  
Synthia P. Mallick ◽  
Donald R. Ryan ◽  
Kaushik Venkiteshwaran ◽  
Patrick J. McNamara ◽  
Brooke K. Mayer
Keyword(s):  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Electro Oxidation ◽  
Reactive Phosphorus

scholarly journals Benthic fluxes of dissolved organic nitrogen in the lower St. Lawrence estuary and implications for selective organic matter degradation

2013 ◽  
Vol 10 (11) ◽  
pp. 7609-7622 ◽  
Author(s):  
M. Alkhatib ◽  
P. A. del Giorgio ◽  
Y. Gelinas ◽  
M. F. Lehmann
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Bottom Water ◽  
Estuarine Sediments ◽  
Internal Source ◽  
Lawrence Estuary ◽  
Element Partitioning ◽  
Sediment Porewaters ◽  
St Lawrence Estuary

Abstract. The distribution of dissolved organic nitrogen (DON) and carbon (DOC) in sediment porewaters was determined at nine locations along the St. Lawrence estuary and in the gulf of St. Lawrence. In a previous manuscript (Alkhatib et al., 2012a), we have shown that this study area is characterized by gradients in the sedimentary particulate organic matter (POM) reactivity, bottom water oxygen concentrations, and benthic respiration rates. Based on the porewater profiles, we estimated the benthic diffusive fluxes of DON and DOC in the same area. Our results show that DON fluxed out of the sediments at significant rates (110 to 430 μmol m−2 d−1). DON fluxes were positively correlated with sedimentary POM reactivity and varied inversely with sediment oxygen exposure time (OET), suggesting direct links between POM quality, aerobic remineralization and the release of DON to the water column. DON fluxes were on the order of 30 to 64% of the total benthic inorganic fixed N loss due to denitrification, and often exceeded the diffusive nitrate fluxes into the sediments. Hence they represented a large fraction of the total benthic N exchange, a result that is particularly important in light of the fact that DON fluxes are usually not accounted for in estuarine and coastal zone nutrient budgets. In contrast to DON, DOC fluxes out of the sediments did not show any significant spatial variation along the Laurentian Channel (LC) between the estuary and the gulf (2100 ± 100 μmol m−2 d−1). The molar C / N ratio of dissolved organic matter (DOM) in porewater and the overlying bottom water varied significantly along the transect, with lowest C / N in the lower estuary (5–6) and highest C / N (> 10) in the gulf. Large differences between the C / N ratios of porewater DOM and POM are mainly attributed to a combination of selective POM hydrolysis and elemental fractionation during subsequent DOM mineralization, but selective adsorption of DOM to mineral phases could not be excluded as a potential C / N fractionating process. The extent of this C- versus N- element partitioning seems to be linked to POM reactivity and redox conditions in the sediment porewaters. Our results thus highlight the variable effects selective organic matter (OM) preservation can have on bulk sedimentary C / N ratios, decoupling the primary source C / N signatures from those in sedimentary paleoenvironmental archives. Our study further underscores that the role of estuarine sediments as efficient sinks of bioavailable nitrogen is strongly influenced by the release of DON during early diagenetic reactions, and that DON fluxes from continental margin sediments represent an important internal source of N to the ocean.

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