Biological groundwater denitrification systems: Lab-scale trials aimed at nitrous oxide production and emission assessment

Capodici, Marco; Avona, Alessia; Laudicina, Vito Armando; Viviani, Gaspare

doi:10.1016/j.scitotenv.2018.02.260

Cited by 30 publications

(7 citation statements)

References 40 publications

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“…fluctuated within 0.6 mg/L in Phases IV and V, which might be caused by dissimilatory nitrate reduction to ammonium (DNRA) (Pu et al, 2014). Because of the dramatic aggregation of carbon sources released from PCL, it was easy to form a high C/N ratio in the local areas, which was beneficial to DNRA (Capodici et al, 2018). This can further explain that with the prolongation of HRT at Phases IV and V, the C/N ratio of R1 increased, which led to the increase of effluent NH 4 + ‐N concentration.…”

Section: Resultsmentioning

confidence: 99%

Effect of hydraulic retention time on performance of autotrophic, heterotrophic, and split‐mixotrophic denitrification systems supported by polycaprolactone/pyrite: Difference and potential explanation

Yuan

Zhu

Guo³

et al. 2022

Water Environment Research

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Biological denitrification is still the most important pathway to purifying nitrate‐containing wastewater. In this study, pyrite (FeS2) and polycaprolactone (PCL) were used as electron donors to construct sole or combined denitrification systems, that is, pyrite‐based autotrophic denitrification (PAD) system, PCL‐supported heterotrophic denitrification (PHD) system, and split‐mixotrophic denitrification system (combined PAD + PHD), all of which were operated under five different hydraulic retention times (HRTs) for 150 days. The results showed that the removal rates (RE) of nitrate (NO3−‐N) and inorganic phosphorus (PO43−‐P) by PAD were 91% and 94%, respectively, but the effluent sulfate (SO42−) concentration was as high as 168.2 mg/L; the removal rate of NO3−‐N by PHD was higher than 99%, but the PO43−‐P could not be removed ideally; the removal rates of NO3−‐N and PO43−‐P by PAD + PHD were higher than 95% and 99%, respectively, and the effluent SO42− concentration was only 7.2 mg/L. Through the analysis of the surface scanning electron microscope (SEM) images of the two kinds of media before and after use, it was found that the coupled mode of PAD + PHD was more favorable for biofilm formation than the sole PAD or PHD process, and the microorganisms in the PAD + PHD mode made more full use of electron donors. Moreover, the biomass of the PAD + PHD mode was lower than that of the PAD or PHD process, but the denitrification efficiency of the coupled mode was more efficient, indicating that the functional microorganisms in the PAD + PHD mode might have a certain synergistic effect. Practitioner Points Removal rates of NO3−, PO43−, and SO42− by PAD were 91%, 94%, and −233%, respectively. Removal rate of NO3− by PHD exceeded 99%, but PO43− could not be removed ideally. Removal rates of NO3−, PO43−, and SO42− by PAD + PHD were 95%, 99%, and 86%, respectively. The coupled mode was more favorable for biofilm formation than the sole PAD or PHD. The coupled mode had lower biomass but got more excellent denitrification efficiency.

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Section: Resultsmentioning

confidence: 99%

Effect of hydraulic retention time on performance of autotrophic, heterotrophic, and split‐mixotrophic denitrification systems supported by polycaprolactone/pyrite: Difference and potential explanation

Yuan

Zhu

Guo³

et al. 2022

Water Environment Research

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“…Nitrates are a very mobile form of nitrogen in soil, representing a dangerous pollutant of waters, and may cause many diseases [ 16 ]. Thus, groundwater nitrate–nitrogen contamination has become a considerable environmental problem and potential risk for human health [ 17 ]. Nevertheless, under anoxic conditions, typical for groundwater, nitrates and nitrites can be reduced via heterotrophic biological denitrification to elemental nitrogen or nitrogen oxides, which do not pose substantial risk to the environment.…”

Section: Introductionmentioning

confidence: 99%

The Behavior of Terbuthylazine, Tebuconazole, and Alachlor during Denitrification Process

Pániková,

Bílková,

Malá

2023

JoX

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Pesticide compounds can influence denitrification processes in groundwater in many ways. This study observed behavior of three selected pesticides under denitrifying conditions. Alachlor, terbuthylazine, and tebuconazole, in a concentration of 0.1 mL L−1, were examined using two laboratory denitrifications assays: a “short” 7-day and a “long” 28-day test. During these tests, removal of pesticides via adsorption and biotic decomposition, as well as the efficiency of nitrate removal in the presence of the pesticides, were measured. No considerable inhibition of the denitrification process was observed for any of the pesticides. On the contrary, significant stimulation was observed after 21 days for alachlor (49%) and after seven days for terbuthylazine (40%) and tebuconazole (36%). Adsorption was in progress only during the first seven days in the case of all tested pesticides and increased only negligibly afterwards. Immediate adsorption of terbuthylazine was probably influenced by the mercuric chloride inhibitor. A biotic loss of 4% was measured only in the case of alachlor.

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“…Unfortunately, excess dissolved organic carbon (DOC) or COD in effluent derived from overutilization of solid carbon source has been reported in some studies (Capodici et al, 2014;Christianson et al, 2016). Although complete denitrification was guaranteed, the excess dosage of solid carbon source largely accounted for the high DOC concentrations in the SPD reactor (Wang et al, 2019;Zhao et al, 2020).…”

Section: Introductionmentioning

confidence: 99%

“…Solid‐phase denitrification (SPD), with natural plant material or synthetic biodegradable polymers as carbon source and biofilm carrier, was proved a promising technology (Wang & Chu, 2016; Zhong et al, 2020). It can be employed to treat many kinds of wastewater, including drinking source water (Cameron & Schipper, 2010), groundwater (Capodici et al, 2018), aquaculture wastewater (Gutierrez‐Wing et al, 2012), and secondary effluent from WWTP (Li et al, 2016). The solid carbon source can be decomposed into small organic molecules by microorganisms to be utilized for their growth.…”

Section: Introductionmentioning

confidence: 99%

Effect of filling ratio and backwash on performance of a continuous‐flow SPD reactor packed with PCL as carbon source

Zhang

Prodanovic

et al. 2021

Water Environment Research

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In this study, three up‐flow fixed‐bed bioreactors, named as A, B, and C, packed with polycaprolactone (PCL) under different filling ratios (31%, 62%, and 93%, respectively), were investigated over a long period (96 days). During the stable period, the mean effluent NO3‐0.333333em- N concentrations in reactors A, B, and C were 1.35 ± 0.50, 1.07 ± 0.41, and 1.03 ± 0.27 mg/L, respectively, which showed the removal of NO3‐0.333333em- N was not closely related to filling ratio (p > 0.05, one‐way ANOVA). However, it was found that biomass in reactor A was 2.13 and 5.55 times in B and C, respectively. Excessively thick biofilm refrained the enzymatic hydrolysis of PCL and biofilm's specific denitrification rate (SDNR). Backwash stimulated organic matter release and enabled biofilm to restore its denitrification activity. The maximum cycle of backwash was 6 days for the lowest filling ratio reactor. Additionally, the utilization rates for denitrification were 83.3%, 86.4%, and 60.5% in reactors A, B, and C, respectively, which was higher after backwash than before backwash. Practitioner points Excessively thick biofilm refrained the enzymatic hydrolysis of PCL. Backwash stimulated organic matter release and enabled biofilm to restore its denitrification activity. The maximum cycle of backwash was 6 days for the lowest filling ratio reactor. A higher utilization rate of PCL for denitrification was observed after backwash.

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Biological groundwater denitrification systems: Lab-scale trials aimed at nitrous oxide production and emission assessment

Cited by 30 publications

References 40 publications

Effect of hydraulic retention time on performance of autotrophic, heterotrophic, and split‐mixotrophic denitrification systems supported by polycaprolactone/pyrite: Difference and potential explanation

Effect of hydraulic retention time on performance of autotrophic, heterotrophic, and split‐mixotrophic denitrification systems supported by polycaprolactone/pyrite: Difference and potential explanation

The Behavior of Terbuthylazine, Tebuconazole, and Alachlor during Denitrification Process

Effect of filling ratio and backwash on performance of a continuous‐flow SPD reactor packed with PCL as carbon source

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