Using numerical simulation of a one stage vertical flow wetland to optimize the depth of a zeolite layer

2016 ◽  
Vol 75 (3) ◽  
pp. 650-658 ◽  
Author(s):  
Bernhard Pucher ◽  
Hernán Ruiz ◽  
Joëlle Paing ◽  
Florent Chazarenc ◽  
Pascal Molle ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Model Calibration ◽  
Oxygen Demand ◽  
Ammonium Nitrogen ◽  
Vertical Flow ◽  
Freundlich Isotherms ◽  
Treatment Performance ◽  
Biokinetic Model ◽  
Vertical Flow Wetland ◽  
Different Depths

This simulation study investigates the treatment performance of a compact French vertical flow wetland using a zeolite layer in order to increase ammonium nitrogen removal. For the modelling exercise, the biokinetic model CW2D of the HYDRUS Wetland Module is used. The calibrated model is able to predict the effect of different depths of the zeolite layer on ammonium nitrogen removal in order to optimize the design of the system. For the model calibration, the hydraulic effluent flow rates as well as influent and effluent concentrations of chemical oxygen demand (COD) and NH4-N have been measured. To model the adsorption capacity of zeolite, Freundlich isotherms have been used. The results present the simulated treatment performance with three different depths of the zeolite layer, 10 cm (default), 15 cm and 20 cm, respectively. The increase of the zeolite layer leads to a significant decrease of the simulated NH4-N effluent concentration.

scholarly journals Effects of selection and compiling strategy of substrates in column-type vertical-flow constructed wetlands on the treatment of synthetic landfill leachate containing bisphenol A

2021 ◽  
Author(s):  
Rajani Ghaju Shrestha ◽  
Daisuke Inoue ◽  
Michihiko Ike
Keyword(s):  
Activated Carbon ◽  
Bisphenol A ◽  
Landfill Leachate ◽  
Low Cost ◽  
Oxygen Demand ◽  
Ammonium Nitrogen ◽  
Pollutant Removal ◽  
Vertical Flow ◽  
Batch Mode ◽  
Synthetic Leachate

Abstract A constructed wetland (CW) is a low-cost, eco-friendly, easy-to-maintain, and widely applicable technology for treating various pollutants in the waste landfill leachate. This study determined the effects of the selection and compiling strategy of substrates used in CWs on the treatment performance of a synthetic leachate containing bisphenol A (BPA) as a representative recalcitrant pollutant. We operated five types of lab-scale vertical-flow CWs using only gravel (CW1), a sandwich of gravel with activated carbon (CW2) or brick crumbs (CW3), and two-stage hybrid CWs using gravel in one column and activated carbon (CW4) or brick crumbs (CW5) in another to treat synthetic leachate containing BPA in a 7-d sequential batch mode for 5 weeks. CWs using activated carbon (CW2 and CW4) effectively removed ammonium nitrogen (NH4-N) (99–100%), chemical oxygen demand (COD) (93–100%), and BPA (100%), indicating that the high adsorption capacity of activated carbon was the main mechanism involved in their removal. CW5 also exhibited higher pollutant removal efficiencies (NH4-N: 94–99%, COD: 89–98%, BPA: 89–100%) than single-column CWs (CW1 and CW3) (NH4-N: 76–100%, COD: 84–100%, BPA: 51–100%). This indicates the importance of the compiling strategy along with the selection of an appropriate substrate to improve the pollutant removal capability of CWs.

scholarly journals In Situ Nutrient Removal from Rural Runoff by A New Type Aerobic/Anaerobic/Aerobic Water Spinach Wetlands

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 1100 ◽  
Author(s):  
Ya-Wen Wang ◽  
Hua Li ◽  
You Wu ◽  
Yun Cai ◽  
Hai-Liang Song ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Constructed Wetland ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Ammonium Nitrogen ◽  
Water Spinach ◽  
Nitrogen And Phosphorus ◽  
The Matrix ◽  
New Type ◽  
Nitrification And Denitrification

Rural runoff with abundant nutrients has become a great threat to aquatic environment. Hence, more and more attention has been focused on nutrients removal. In this study, an improved aerobic/anaerobic/aerobic three-stage water spinach constructed wetland (O-A-O-CW) was used to improve the removal of nitrogen and phosphorus of rural runoff. The removal rate of the target pollutants in O-A-O-CW was compared with the common matrix flow wetland as well as the no-plant wetland. The results showed that the O-A-O-CW significantly increased the chemical oxygen demand, total phosphorus, ammonium-nitrogen, nitrate, and total nitrogen removal rate, and the corresponding removal rate was 55.85%, 81.70%, 76.64%, 89.78%, and 67.68%, respectively. Moreover, the best hydraulic condition of the wetland, including hydraulic retention time and hydraulic loading, was determined, which were 2 days and 0.45 m3·m−2·day−1, respectively. Furthermore, the removal mechanism of the constructed wetland was thoroughly studied, which included the adsorption of nitrogen and phosphorus by the matrix and water spinach, and the nitrification and denitrification by the bacteria. The results demonstrated that the mechanisms of nitrogen removal in the new type wetland were principally by the nitrification and denitrification process. Additionally, adsorption and precipitation by the matrix are mainly responsible for phosphorus removal. These results suggested that the new O-A-O-CW can efficiently removal nutrients and enhance the water quality of the rural runoff.

scholarly journals Performance of a French system of vertical flow wetlands (first stage) operating with an extended feeding cycle

2019 ◽  
Vol 80 (8) ◽  
pp. 1443-1455 ◽  
Author(s):  
Camila Maria Trein ◽  
Jorge Alejandro García Zumalacarregui ◽  
Mirene Augusta de Andrade Moraes ◽  
Marcos von Sperling
Keyword(s):  
Oxygen Demand ◽  
Climatic Conditions ◽  
Nitrification Rate ◽  
Vertical Flow ◽  
Intensive Monitoring ◽  
The Third ◽  
Treatment Performance ◽  
N Removal ◽  
Feeding Cycle ◽  
Deposit Layer

Abstract The aim of this work was to evaluate the treatment performance in the first stage of a vertical flow constructed wetland – French system (VCW-FS) over an extended feeding period (seven days), in two parallel units, for a population equivalent (p.e.) around 100 inhabitants (total of 0.6 m²·p.e.−1), under Brazilian tropical climatic conditions. One of the units had a greater surface sludge deposit layer, accumulated over nine years of operation, while the other unit had its sludge removed prior to the experiments. Four intensive monitoring campaigns covering all days of the feeding cycle were undertaken and the results were compared with those obtained from the conventional monitoring. The results indicated that, over the days of the feeding cycle, dissolved oxygen concentrations decreased, but were still kept at sufficiently high values for the removal of organic matter. Therefore, chemical oxygen demand (COD) removal, although not high, remained acceptable for compliance with local discharge standards during the whole the period. The NH4+-N removal efficiency and NO3−-N production were higher at the beginning of the feeding cycle, as a result of the more well-established aerobic conditions, with the nitrification rate decreasing from the third day of feeding. The sludge deposit seemed to hinder liquid percolation, especially at the end of the feeding cycle, thus affecting oxygen transfer. Due to the variability of the results over the feeding cycle, if sampling is to be done once a week, it is important to identify the sampling day that best represents the system's performance.

scholarly journals The effect of aerated rock filter geometry on the rate of nitrogen removal from facultative pond effluents

2011 ◽  
Vol 63 (5) ◽  
pp. 841-844 ◽  
Author(s):  
R. Hamdan ◽  
D. D. Mara
Keyword(s):  
Nitrogen Removal ◽  
Ammonium Nitrogen ◽  
Horizontal Flow ◽  
Vertical Flow ◽  
Stabilization Pond ◽  
Waste Stabilization Pond ◽  
Nitrate N ◽  
N Removal ◽  
Ammonium N ◽  
Waste Stabilization

Rock filters are an established technology for polishing waste stabilization pond effluents. However, they rapidly become anoxic and consequently do not remove ammonium-nitrogen. Horizontal-flow aerated rock filters (HFARF), developed to permit nitrification and hence ammonium-N removal, were compared with a novel vertical-flow aerated rock filter (VFARF). There were no differences in the removals of BOD5, TSS and TKN, but the VFARF consistently produced effluents with lower ammonium-N concentrations (<0.3 mg N/L) than the HFARF (0.8−1.5 mg N/L) and higher nitrate-N concentrations (24–29 mg N/L vs. 17–24 mg N/L).

scholarly journals Treatment of Winery Wastewater Using Bench-Scale Columns Simulating Vertical Flow Constructed Wetlands with Adsorption Media

2020 ◽  
Vol 10 (3) ◽  
pp. 1063 ◽  
Author(s):  
Katelyn Skornia ◽  
Steven I. Safferman ◽  
Laura Rodriguez-Gonzalez ◽  
Sarina J. Ergas
Keyword(s):  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Oxygen Demand ◽  
Nitrogen Adsorption ◽  
Small Scale ◽  
Vertical Flow ◽  
Wine Making ◽  
Bench Scale ◽  
Winery Wastewater ◽  
Start Up

Wastewater produced during the wine-making process often contains an order of magnitude greater chemical oxygen demand (COD) concentration than is typical of domestic wastewater. This waste stream is also highly variable in flow and composition due to the seasonality of wine-making. The recent growth of small-scale wineries in cold climates and increasing regulations present a need for low-cost, easily-operable treatment systems that do not require large amounts of land, yet maintain a high level of treatment in cool temperatures. This research investigates the use of a subsurface vertical flow constructed wetland (SVFCW) to treat winery wastewater. In this study, clinoptilolite, tire chips, and a nano-enhanced iron foam were used to enhance bench-scale gravel cells to adsorb ammonia, nitrate, and phosphorus, respectively. The treatment systems, without nitrogen adsorption media, performed well, with >99% removal of COD and 94% removal of total nitrogen. Treatment systems with the nitrogen adsorption media did not enhance nitrogen removal. Equilibrium was reached within two weeks of start-up, regardless of prior inoculation, which suggests that microbes present in the winery wastewater are sufficient for the start-up of the wastewater treatment system; therefore, the seasonality of winery wastewater production will not substantially impact treatment. Operating the treatment systems under cool temperatures did not significantly impact COD or total nitrogen removal. Further, the use of nano-enhanced iron foam exhibited 99.8% removal of phosphorus, which resulted in effluent concentrations that were below 0.102 mg/L P.

Simultaneous COD and Nitrogen Removal in Up-Flow Microaerobic-Oxic (M/O) Process for Domestic Wastewater Treatment

2013 ◽  
Vol 838-841 ◽  
pp. 2739-2744
Author(s):  
Shuang Zhao ◽  
Cui Ping Wang
Keyword(s):  
Wastewater Treatment ◽  
Nitrogen Removal ◽  
Energy Use ◽  
Particle Diameter ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Ammonium Nitrogen ◽  
Domestic Wastewater Treatment ◽  
Stable Performance ◽  
Biological Nitrogen

A novel process for improving the energy use and treatment efficiency of the biological nitrogen removal process, up-flow microaerobic-oxic (M/O) process which is composed of up-flow micro-aerobic and aeration was proposed based on a laboratory scale for domestic wastewater treatment, the dissolved oxygen (DO) in up-flow micro-aerobic was in the range of (0~0.5) mg/L. The M/O process performance under different hydraulic retention time (HRT) and Internal return ratio (r) was investigated. Under the optimal conditions, the average removal efficiencies of chemical oxygen demand (COD), total nitrogen (TN) and ammonium nitrogen (NH4+-N) were 89.1%, 64.1%, and 96.6 % with effluent concentrations of COD, TN and NH4+-N less than 50,15 and 8mg/L, respectively. The distribution of sludge particles diameter and microbial activity of activated sludge were also measured, the mean particle diameter was in the range of 180~250μm and the SOURT was 13.11 mgO2/(gMLVSSh). Up-flow micro-aerobic (M/O) reactor has the advantages of more stable performance and better resistance to the load shock than the conventional A/O process within continuous running period of 130 days.

scholarly journals French vertical-flow constructed wetlands in mountain areas: how do cold temperatures impact performances?

2015 ◽  
Vol 71 (8) ◽  
pp. 1219-1228 ◽  
Author(s):  
S. Prost-Boucle ◽  
O. Garcia ◽  
P. Molle
Keyword(s):  
Constructed Wetlands ◽  
Nitrogen Removal ◽  
Winter Season ◽  
Oxygen Demand ◽  
Vertical Flow ◽  
Mountain Areas ◽  
Cold Temperatures ◽  
Vertical Flow Constructed Wetlands ◽  
Online Measurements ◽  
Solids Removal

The French version of vertical-flow constructed wetlands (VFCWs) is characterized by treating directly raw wastewater on a first-stage filter. VFCW is a well developed technology with more than 3,500 plants in operation in France. However, VFCW performance may be affected under the low temperatures reached in mountain areas during winter. The effect of cold conditions over 12 plants, ranging from 75 to 1,900 person equivalent and from 680 to 1,500 m above sea level, was studied over 2 years. The plant hydraulic loads, and air and filter temperatures were continuously measured. In addition, 24-h flow proportional sampling, at each stage of treatment, was conducted in summer (as a reference) and winter. Online measurements of ammonium and nitrates were also analyzed to describe the nitrogen removal dynamics. Since no impact on chemical oxygen demand (COD), biochemical oxygen demand (BOD) and suspended solids removal was observed, the effect of cold temperatures on nitrification was further analyzed. Nitrogen removal was relatively unaffected during winter season. Significant effects were confirmed only for the second stage for loads above 10 gTKN/m2/d (TKN: total Kjeldahl nitrogen). Temperature profiles allowed analysis of the filter buffer capacity in terms of freezing. Under minimal air temperature of −19 °C, no critical operation was observed, although design and operation recommendations can be provided to ensure suitable plant performances.

scholarly journals Performance and microbial community in a combined VF-HF system for the advanced treatment of secondary effluent

2018 ◽  
Vol 2017 (3) ◽  
pp. 695-706 ◽  
Author(s):  
Zhichao Zhu ◽  
Hengfeng Miao ◽  
Yajing Zhang ◽  
Jian Cui ◽  
Zhenxing Huang ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Constructed Wetland ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Community Analysis ◽  
Denitrifying Bacteria ◽  
Ammonium Nitrogen ◽  
Pollutant Removal ◽  
Stable Operation ◽  
Secondary Effluent

Abstract In this study, a laboratory-scale system combined a vertical flow constructed wetland (VF) with a horizontal flow constructed wetland (HF), which was used to treat the secondary effluent of a wastewater treatment plant. Removal efficiencies of 67.02%, 89.80%, 90.31% and 75.38% were achieved by the system for chemical oxygen demand (COD), ammonium nitrogen (NH4+-N), total nitrogen (TN) and total phosphorus (TP), respectively. The VF showed much higher average loading rates of COD, TP, NH4+-N and TN (7.96 g/m2/d, 0.076 g/m2/d, 0.31 g/m2/d and 0.99 g/m2/d) than in HF (0.65 g/m2/d, 0.016 g/m2/d, 0.25 g/m2/d and 0.50 g/m2/d), during the stable operation period. Biodegradation played a major role in pollutant removal, especially for COD and TN. The results of bacterial community analysis indicated that heterotrophic denitrifying bacteria (Hydrogenophaga and Flavobacterium) were the dominant contributors for nitrogen removal in the VF, while heterotrophic denitrifying bacteria (Rhodobacter, Flavobacterium and Dechloromonas) and the autotrophic denitrifying bacteria Sulfurimonas played the principal roles for nitrogen removal in the HF. Redundancy analyses showed that COD and NH4+-N were the important factors affecting the distribution of nitrogen removal bacteria in the VF, while pH, dissolved oxygen and oxidation-reduction potential were the key factors influencing the distribution of nitrogen removal bacteria in the HF.

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