Effect of by-pass and effluent recirculation on nitrogen removal in hybrid constructed wetlands for domestic and industrial wastewater treatment

Torrijos, Verónica; Gonzalo, O.G.; Trueba-Santiso, Alba; Ruíz, I.; Soto, M.

doi:10.1016/j.watres.2016.07.028

Cited by 79 publications

(20 citation statements)

References 27 publications

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“…In Periods I and III wetlands units exhibited an outstanding TN reduction, with removal rates of 6.6 ± 1.4 and 6.2 ± 1.8 g TN m -2 d -1 , respectively. These values agree with those reported by Torrijos et al (2016) evaluating the effect of effluent recirculation in a hybrid CW system (HF-VF) treating synthetic domestic wastewater, where a TN removal efficiency of about 80% at loading rates ranging from 2 to 8 g TN m -2 was observed. High TN removal rates (8.4 g TN m -2 d -1 ) were also performed by a recirculated hybrid CW system (VF-HF) treating high strength industrial wastewater.…”

Section: Total Nitrogen Removalsupporting

confidence: 90%

“…The recirculation strategy was also recently tested in hybrid CWs system at pilot-scale consisting of an anaerobic reactor followed by a HF and VF wetlands and average of 66% of TN removal was observed when applying 100% recirculation, as opposed to 29% without recirculation (Ayaz et al, 2012). Moreover, various lab-scale hybrid constructed wetland configurations containing HF and VF wetlands showed stable average of 80% TN removal under a load of 2-8 g TN m -2 d -1 (Torrijos et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

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Enhancement of total nitrogen removal through effluent recirculation and fate of PPCPs in a hybrid constructed wetland system treating urban wastewater

Ávila

Pelissari

Sezerino

et al. 2017

Science of The Total Environment

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The effect of effluent recirculation on the removal of total nitrogen (TN) and eight pharmaceuticals and personal care products (PPCPs) was evaluated during 9months in an experimental hybrid constructed wetland (CW) system applied in the treatment of urban wastewater. An Imhoff tank was followed by three stages of CWs (two 1.5-m vertical subsurface flow (VF) beds alternating feed-rest cycles, a 2-m horizontal (HF) and a 2-m free water surface (FWS) wetland in series). A fraction of the final effluent was recycled back to the Imhoff tank with a recirculation rate of 50% (hydraulic loading rate=0.37md). The system's performance varied throughout the study. In Period I (summer) consistently high load removal efficiencies of TN (89±5%) and a removal rate of 6.6±1.4gTNmd were exhibited. In Period II (fall), the poor performance of the FWS during the senescence of macrophytes caused a large increase in organic matter, solids and nutrient concentrations, drastically deteriorating water quality. The determination of PPCPs was conducted during this period. Recalcitrant compounds, namely sulfamethoxazole, carbamazapine, TCEP and sucralose were negligibly removed in all CWs. However, noteworthy was the ≈30% removal of sucralose in the VF wetland. Caffeine (80%) and fluoxetine (27%) showed similar elimination rates in both VF and HF units, whereas trimethoprim and DEET were significantly better removed in the VF than in the HF. The concentration of the four latter compounds showed a severe increase in the FWS, indicating possible desorption from the sediment/biomass during adverse conditions. Harvesting of the aboveground biomass in this unit returned the system's performance back to normality (Period III), achieving 77±7% TN removal despite the winter season, proving effluent recirculation as an effective strategy for TN removal in hybrid CW systems when stringent restrictions are in place.

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Section: Total Nitrogen Removalsupporting

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Enhancement of total nitrogen removal through effluent recirculation and fate of PPCPs in a hybrid constructed wetland system treating urban wastewater

Ávila

Pelissari

Sezerino

et al. 2017

Science of The Total Environment

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“…Vertical‐flow—horizontal‐flow constructed wetland is the most commonly used hybrid system for sewage treatment. On the other hand, the use of a horizontal‐flow—vertical‐flow system has been reported only for municipal sewage treatment . The vertical‐flow—horizontal‐flow configuration was found to be more efficient in ammonia removal than other hybrid configurations, which coincided well with this study …”

Section: Resultssupporting

confidence: 90%

“…On the other hand, the use of a horizontal-flow-vertical-flow system has been reported only for municipal sewage treatment. [38] The vertical-flow-horizontal-flow configuration was found to be more efficient in ammonia removal than other hybrid configurations, which coincided well with this study. [32] As shown in Figure 5, with regard to the tail water quality, if the NH 4 þ -N removal rate was considered as the key index, then the weight increased (>5.10) and the ranking of vertical-flow wetlandecological pond-surface-flow wetland-horizontal-flow wetland process and vertical-flow wetland-horizontal-flow wetland process decreased; however, if the organic matter removal rate was taken into account (>7.60), then the ranking of these two processes increased.…”

Section: Upgrading Assessment Results and Discussion On Improving Watsupporting

confidence: 90%

Performance Evaluation of Constructed Wetlands Treating Wastewater Treatment Plant Effluent in Taihu Lake, China

Shen

Huang

Zhang

et al. 2017

CLEAN Soil Air Water

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Constructed wetlands are often used for advanced treatment of the secondary effluent of municipal wastewater treatment plants (WWTPs). Through assessing wetlands based on economic, technical, environmental, and social impacts, an optimal process is selected. In this study, a set of assessment methods for wetland treatment technology is established: The analytic hierarchy process (AHP) is used to establish the evaluation index system; the entropy weight method is employed to calculate the index weights; and the preference ranking organization method for enrichment evaluation (PROMETHEE) is utilized for ranking of the selected treatment technologies. Then four processes applied in Taihu Lake basin, China are evaluated. The results show the following ranking: Vertical-flow wetlandecological pond-surface-flow wetland-horizontal-flow wetland, vertical-flow wetland-horizontal-flow wetland, ecological pond-horizontal-flow wetlandsurface-flow wetland, and ecological ditch-ecological pond. The wetland exhibits certain universality and space portability with regard to treatment of municipal WWTP effluent. From the view of comprehensive benefits, the ranking of the treatment technology based on the vertical-flow wetland is high (Φ values between 0.0224 and 0.0349), whereas that based on the ecological pond is low (Φ values between À0.2086 and À0.2652), owing to the mechanism of the process itself and the role of microorganisms in the system. Moreover, for organic matter removal, a vertical-flow wetland process is recommended (48%), whereas for the removal of N contamination, an integrated-flow wetland process is suggested (31.2% for NH 3 -N, 32.4% for TN removals).

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“…In addition, carbon source is a controlling factor in the process of denitrification. It is usually supplied by wastewater, soil, plant root exudates or can be improved in occasions throughout untreated influent bypass or step-feeding (Torrijos et al, 2016;Vymazal and Kröpfelová, 2008;Songliu et al, 2009), but an external source, such as glucose, sodium acetate and fructose may be needed when influents contain low C/N ratios (Chatterjee and Woo, 2009). Hydraulic load (H L ) and hydraulic retention time (HRT) are some of the most important factors that control the performance of subsurface flow constructed wetland systems.…”

Section: Introductionmentioning

confidence: 99%

Phytoremediation potential of Vetiveria zizanioides and Oryza sativa to nitrate and organic substance removal in vertical flow constructed wetland systems

Almeida

Ribeiro

Carvalho

et al. 2019

Ecological Engineering

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The aim of this work was to determine the potential of phytoremediation of Vetiveria zizanioides and Oryza sativa to nitrate (NO 3 −-N) and organic matter (COD-chemical oxygen demand) removal in subsurface vertical flow constructed wetland systems (VFCWs). The tests were carried out in models of 2 beds with a surface of 0.24 m 2 and depth 0.70 m each at various hydraulic loads (H L) and COD constant in influente wastewater. The VFCW-1 bed was planted with the Vetiveria zizanioides and the VFCW-2 bed with the Oryza sativa. During the 22 weeks of research, the hydraulic load of the analyzed beds was: H L1 = 148 dm 3 •m −2 •d −1 , H L2 = 239 dm 3 •m −2 •d −1 , H L3 = 350 dm 3 •m −2 •d −1 , H L4 = 473 dm 3 •m −2 •d −1. The VFCWs were fed from two reservoirs, one with mineral medium and nitrate, and the other one with fructose as organic matter. Based on the conducted tests, it was found that in both analyzed systems (VFCW-1 and VFCW-2) the highest NO 3 −-N removal rate was found under H L2-the median is 59 and 42% respectively. The most effective removal of COD in the VFCW-1 system was obtained at a H L2-55%, while in the system VFCW-2 at a H L1-43%. The research shows that the low H L and high COD/NO 3 −-N ratio ensures good effects of nitrate and organic matter removal in VF type constructed wetland systems. It has been shown that the analyzed plants, especially Vetiveria zizanioides have good phytoremediation potential in the field of nitrate nitrogen and organic substance removal and can be recommended for use on a full scale of technology. electron donor to obtain energy for growth and maintenance, and produce nitrogen gas (N 2), nitrous oxide (N 2 O) or nitric oxide (NO) (Saeed and Sun, 2012). There are some factors that influence denitrification, including, appropriate redox potential (Eh), temperature, pH, soil type, moisture saturation degree, availability of nitrate and carbon, absence of oxygen, and plants species of the wetland system

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Effect of by-pass and effluent recirculation on nitrogen removal in hybrid constructed wetlands for domestic and industrial wastewater treatment

Cited by 79 publications

References 27 publications

Enhancement of total nitrogen removal through effluent recirculation and fate of PPCPs in a hybrid constructed wetland system treating urban wastewater

Enhancement of total nitrogen removal through effluent recirculation and fate of PPCPs in a hybrid constructed wetland system treating urban wastewater

Performance Evaluation of Constructed Wetlands Treating Wastewater Treatment Plant Effluent in Taihu Lake, China

Phytoremediation potential of Vetiveria zizanioides and Oryza sativa to nitrate and organic substance removal in vertical flow constructed wetland systems

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