scholarly journals Effect of the Influent Substrate Concentration on Nitrogen Removal from Summer to Winter in Field Pilot-Scale Multistage Constructed Wetland–Pond Systems for Treating Low-C/N River Water

2021 ◽  
Vol 13 (22) ◽  
pp. 12456
Author(s):  
Tao Wang ◽  
Liping Xiao ◽  
Hongbin Lu ◽  
Shaoyong Lu ◽  
Xiaoliang Zhao ◽  
...  
Keyword(s):  
River Water ◽  
Constructed Wetlands ◽  
Nitrogen Removal ◽  
Constructed Wetland ◽  
Substrate Concentration ◽  
Removal Rate ◽  
Carbon Sources ◽  
River Estuary ◽  
Pilot Scale ◽  
Surface Flow

The quality of micropolluted water is unstable and its substrate concentration fluctuates greatly. The goal is to predict the concentration effect on the treatment of nitrogen in a river with an actual low C/N ratio for the proposed full-scale Xiaoyi River estuary wetland, so that the wetland project can operate stably and perform the water purification function effectively in the long term. Two pilot-scale multistage constructed wetland–pond (MCWP) systems (S1 and S2, respectively) based on actual engineering with the same “front ecological oxidation ponds, two-stage horizontal subsurface flow constructed wetlands and surface flow constructed wetlands (SFCWs) as the core and postsubmerged plant ponds” as the planned process were constructed to investigate the effect of different influent permanganate indexes (CODMn) and total nitrogen (TN) contents on nitrogen removal from micropolluted river water with a fixed C/N ratio from summer to winter in the field. The results indicate that the TN removal rate in the S1 and S2 systems was significant (19.56% and 34.84%, respectively). During the process of treating this micropolluted water with a fixed C/N ratio, the influent of S2 with a higher CODMn concentration was conducive to the removal of TN. The TN removal rate in S2 was significantly affected by the daily highest temperature. There was significant nitrogen removal efficiency in the SFCWs. The C/N ratio was a major determinant influencing the nitrogen removal rate in the SFCWs. The organic matter release phenomenon in SFCWs with high-density planting played an essential role in alleviating the lack of carbon sources in the influent. This research strongly supports the rule that there is seasonal nitrogen removal in the MCWPs under different influent substrate concentrations, which is of guiding significance for practical engineering.

scholarly journals PARAMETERS EVALUATION OF MUNICIPAL WASTE WATER AFTER TREATMENT USING SUB SURFACE FLOW CONSTRUCTED WETLAND IN EKANT PARK BHOPAL

2016 ◽  
Vol 4 (12) ◽  
pp. 24-30
Author(s):  
Shalini Saxena
Keyword(s):  
Constructed Wetlands ◽  
Constructed Wetland ◽  
Suspended Solids ◽  
Removal Rate ◽  
Surface Flow ◽  
Chemical Parameters ◽  
Nitrogen And Phosphorus ◽  
Public Park ◽  
Physico Chemical ◽  
Natural Wetlands

Land areas which are wet during part or all of the year are referred as wetlands. Constructed wetlands are manmade systems that mimic the functions of natural wetlands and applied for wastewater treatment. Aim of the present study is to investigate the feasibility of using a Tracheophyte, Phragmiteskarka in constructed wetland for treatment of wastewater in an public park. The daily inlet and outlet wastewater physico-chemical parameters were analysed during the period of two months. The parameters studied were pH, BOD, COD, DO, Total Suspended Solids, Total Dissolved Solids, Nitrogen and Phosphorus. The percentage removal of the parameters were analysed and studied until the percent removal rate gets stabilized. The study showed that the subsurface flow constructed wetlands are best alternative among modern treatments.

scholarly journals Nitrogen removal from summer to winter in a field pilot-scale multistage constructed wetland-pond system

2020 ◽  
Author(s):  
Liping Xiao ◽  
Tao Wang ◽  
Hongbin Lu ◽  
Shaoyong Lu ◽  
Jiaxin Li ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Constructed Wetland ◽  
Pilot Scale ◽  
Surface Flow ◽  
Treatment Unit ◽  
Pond System ◽  
Load Rate ◽  
Plant Harvesting

Abstract Background Single-stage constructed wetlands (CWs) has a single ecological service function and is greatly affected by temperature, which are general in removal of total nitrogen. Multistage hybrid CWs were proven to capable of enhancing removal of nitrogen. Therefore, this study aimed to explore the variation in nitrogen removal in the combined CWs-pond process from summer to winter and the contribution of plant harvesting and the functions of bacteria to nitrogen removal. Methods A pilot-scale multistage constructed wetland-pond system (MCWP) with the process of "the pre-ecological oxidation pond + the two-level horizontal subsurface flow constructed wetland (HSCW) + the surface flow constructed wetland (SFCW) and the submerged plant pond (SPP)" was used to treat actual polluted river water in the field. During the 124 days of operation, the nitrogen concentrations in the units influent and effluent of the system were measured every two days, and the plant height in HSCWs and SFCW was measured once per month. When the system operated stably to the 72nd day, the substrates in the CWs were sampled to analyze the bacterial community structure and composition. Results The concentration of total nitrogen (TN) in the MCWP gradually decreased from 3.46 mg/L to 2.04 mg/L, and the average removal efficiency of TN was approximately 40.74%. The SPP performed the best among all units, and the TN removal efficiency was as high as 16.08%. The TN removal efficiency was significantly positively affected by the daily highest temperature. A formula between the total TN removal efficiency and the highest temperature was obtained by nonlinear fitting. The TN removal load rate in the HSCWs was 2.7–3.7 times that of the SFCW. Furthermore, the TN transformed by Iris pseudacorus L. accounted for 54.53% in the SFCW. Conclusion We found that the significant positive correlation between the daily highest temperature and the total TN removal rate a field MCWP system. The SFCW, as an advanced treatment unit, increased the proportion of nitrogen removed by plant harvesting. The bacteria completed the nitrogen cycle in the SFCW, which had high-density planting, through a variety of nitrogen removal pathways.

Treatment of Polluted River Water Using Surface Flow Constructed Wetlands in Xinyi River Floodplain

2011 ◽  
Vol 396-398 ◽  
pp. 1909-1913
Author(s):  
Jian Qiang Wu ◽  
Min Wang ◽  
Jian Wu ◽  
Hao Tang
Keyword(s):  
River Water ◽  
Removal Rate ◽  
Typha Latifolia ◽  
Pilot Scale ◽  
Lythrum Salicaria ◽  
Surface Flow ◽  
Polluted River ◽  
Canna Indica ◽  
N Removal ◽  
Scale Surface

Treatment of polluted river water with great variations of water quality using pilot-scale Surface Flow Constructed Wetland (SFW) was studied in this paper. The main results show that: When the influent concentrations of CODMn and NH4+-N were 11.69~60.00 mg•L-1 and 1.37~20.18 mg•L-1, the CODMn and NH4+-N removal rate of SFW which planted Lythrum salicaria, Canna indica, Typha latifolia and Scirpus locustris were 26.44％、40.12％、46.71％、28.23％ and 64.27％、70.49％、66.78%、58.52%. Typha latifolia and Canna indica have stronger ability for purifying pollutants. Scirpus locustris has strongest ability of overhead flooding, it can resist inundation over 22 days and still live. Lythrum salicaria has lowest ability of overhead flooding, it only can resist inundation 7 days.

scholarly journals Effects of Partial Saturation on Nitrogen Removal and Bacterial Community in Vertical-Flow Constructed Wetlands

2021 ◽  
Author(s):  
Khadija kraiem ◽  
Hamadi Kallali ◽  
Rim Werheni Ammeri ◽  
salma Bessadok ◽  
Naceur Jedidi
Keyword(s):  
Constructed Wetlands ◽  
Nitrogen Removal ◽  
Constructed Wetland ◽  
Removal Rate ◽  
Vertical Flow ◽  
Partial Saturation ◽  
Denitrifying Bacterium ◽  
Saturation Condition ◽  
Vertical Flow Constructed Wetland ◽  
Kjeldahl Nitrogen

Abstract The laboratory-scale pilot of constructed wetlands has been in operation for six months; (1) an unsaturated vertical flow constructed wetland (UVF-CW), this system was used to represent the classic vertical constructed wetlands, (2) a saturated vertical flow constructed wetland (SVF-CW), to evaluate the effects of the saturated condition on nitrogen removal and composition of the microbial community. The results showed that the saturation condition positiveley influenced the removal efficiencies of the nitrogen,, the aeverage removal rate of the total kjeldahl nitrogen increased from 56% in unsaturated vertical flow constructed wetland (UVF-CW) to 63% in saturated vertical flow constructed wetland ( SVF-CW). In addition, the microbial communities also was affected by the saturation condition, the relative abundances of nitrifying bacterium in UVF-CW are 13.8% (Nitrosomonas), 7.2% (Nitrosospira), 18.1% (Nitrospira) and 15.3% (Nitrobacter). In contrast, in SVF-CW, Nitrosomonas, Nitrosospira, Nitrospira and Nitrobacter only accounted for 6.8%, 5.6%, 7.4% and 10.6% respectively. However, the saturation condition seemed to increase denitrifying bacterium more than three times, in unsaturated vertical flow constructed wetland, only Pseudomonas (6.5%) and Paracoccus (4.85%) were detected, but in saturated vertical flow constructed wetland (SVF-CW), the abundance of Pseudomonas (13.08%) and Paracoccus (9.74%) were increased, and three other groups of denitrifying bacteria were also detected as Zoogloea (3.32%), Thauera (5.41%) and Thiobacillus (3).

Enhancement of nitrogen removal in subsurface flow constructed wetlands employing a 2-stage configuration, an unsaturated zone, and recirculation

1995 ◽  
Vol 32 (3) ◽  
pp. 59-67 ◽  
Author(s):  
Kevin D. White
Keyword(s):  
Constructed Wetlands ◽  
Nitrogen Removal ◽  
Constructed Wetland ◽  
Subsurface Flow ◽  
Great Promise ◽  
Effluent Recirculation ◽  
Wetland Treatment ◽  
Subsurface Flow Constructed Wetlands ◽  
Inlet Zone ◽  
Bod Removal

Constructed wetland technology is currently evolving into an acceptable, economically competitive alternative for many wastewater treatment applications. Although showing great promise for removing carbonaceous materials from wastewater, wetland systems have not been as successful at nitrification. This is primarily due to oxygen limitations. Nitrification does occur in conventional wetland treatment systems, but typically requires long hydraulic retention times. This paper describes a study that first evaluated the capability of subsurface flow constructed wetlands to treat a high strength seafood processor wastewater and then evaluated passive aeration configurations and effluent recirculation with respect to nitrogen treatment efficiency. The first stage of a 2-stage wetland treatment system exhibited a relatively short hydraulic retention time and was designed for BOD removal only. The second stage wetland employed an unsaturated inlet zone and effluent recirculation to enhance nitrification. Results indicate that organic loading, and thus BOD removal, in the first stage wetland is key to optimal nitrification. Passive aeration through an unsaturated inlet zone and recirculation achieved up to 65-70 per cent ammonia nitrogen removal at hydraulic retention times of about 3.5 days. Inlet zone configuration and effluent recirculation is shown to enhance the nitrogen removal capability of constructed wetland treatment systems.

scholarly journals Variation of Bacterial and Archaeal Community Structures in a Full-Scale Constructed Wetlands for Wastewater Treatment

Archaea ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Xiu-lu Lang ◽  
Xiang Chen ◽  
Ai-ling Xu ◽  
Zhi-wen Song ◽  
Xin Wang ◽  
...  
Keyword(s):  
Microbial Community ◽  
Constructed Wetlands ◽  
Relative Abundance ◽  
Constructed Wetland ◽  
Free Surface Flow ◽  
Archaeal Community ◽  
Illumina Miseq ◽  
Surface Flow ◽  
Community Structures ◽  
Soil And Water

Microorganisms play important roles in the reduction of organic and inorganic pollutants in constructed wetlands used for the treatment of wastewater. However, the diversity and structure of microbial community in constructed wetland system remain poorly known. In this study, the Illumina MiSeq Sequencing of 16S rDNA was used to analyze the bacterial and archaeal microbial community structures of soil and water in a free surface flow constructed wetland, and the differences of bacterial communities and archaeal compositions between soil and water were compared. The results showed that the Proteobacteria were the dominant bacteria, making up 35.38%~48.66% relative abundance. Euryarchaeotic were the absolute dominant archaea in the influent sample with the relative abundance of 93.29%, while Thaumarchaeota showed dominance in the other three samples, making up 50.58%~75.70%. The relative abundances of different species showed great changes in bacteria and archaea, and the number of dominant species in bacteria was much higher than that in archaea. Compared to archaea, the community compositions of bacteria were more abundant and the changes were more significant. Meanwhile, bacteria and archaea had large differences in compositions between water and soil. The microbial richness in water was significantly higher than that in soil. Simultaneously, soil had a significant enrichment effect on some microbial flora.

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.

Performance assessment of pilot horizontal sub-surface flow constructed wetlands for removal of diesel from wastewater by Scirpus grossus

2013 ◽  
Vol 68 (10) ◽  
pp. 2271-2278 ◽  
Author(s):  
Israa Abdulwahab Al-Baldawi ◽  
Siti Rozaimah Sheikh Abdullah ◽  
Nurina Anuar ◽  
Fatihah Suja ◽  
Mushrifah Idris
Keyword(s):  
Constructed Wetlands ◽  
Suspended Solids ◽  
Flow System ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Surface Flow ◽  
Total Petroleum Hydrocarbon ◽  
Physical Parameters ◽  
Contaminated Water ◽  
Development Technology

One of the appropriate development technology options for the treatment of wastewater contaminated with diesel is constructed wetlands (CWs). Throughout 72 days of exposure, sampling was carried out for monitoring of physical parameters, plant growth and the efficiency of total petroleum hydrocarbon (TPH) removal, as an indication for diesel contamination, to assess the pilot-scale performance. Four pilot CWs with a horizontal sub-surface flow system were applied using the bulrush of Scirpus grossus. The CWs were loaded with different diesel concentrations of 0, 0.1, 0.2 and 0.25% (Vdiesel/Vwater). The TPH removal efficiencies were 82, 71, and 67% at the end of 72 days for diesel concentrations of 0.1, 0.2, and 0.25% respectively. In addition, the high removal efficiency of total suspended solids and chemical oxygen demand (COD) were 100 and 75.4% respectively, for a diesel concentration of 0.1%. It was concluded that S. grossus is a potential plant that can be used in a well-operated CW for restoring 0.1% diesel-contaminated water.

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