scholarly journals On the performance of a pilot hybrid constructed wetland for stormwater recovery in Mediterranean climate

2019 ◽  
Vol 79 (6) ◽  
pp. 1051-1059 ◽  
Author(s):  
D. Ventura ◽  
S. Barbagallo ◽  
S. Consoli ◽  
M. Ferrante ◽  
M. Milani ◽  
...  

Abstract The overall efficiency of a pilot-scale hybrid constructed wetland (H-CW), located on a retail store's parking area in Eastern Sicily, for alternative treatment of stormwater runoff and of sequential batch reactor (SBR) effluent was evaluated. Experimental activities were focused on system performances, including wastewater (WW) quality and hydraulic monitoring. System design, macrophyte growth and seasonal factors influenced the pilot plant performance. Very high removal efficiency for microbial indicators were reported within the subsurface horizontal flow unit (HF), playing a strategic role for Clostridium perfringens. The algal growth occurred in the free water surface (FWS) unit and inhibited removal efficiencies of total suspended solids (TSS), biochemical oxygen demand (BOD5) and chemical oxygen demand (COD), impairing water quality. The whole H-CW showed good efficiency in trace metals removal, especially for Pb, Zn, and Cu. Preliminary results suggested the reliability of the H-CW technology in decentralised water treatment facilities for enhancing water recovery and reuse.

2015 ◽  
Vol 71 (7) ◽  
pp. 1088-1096 ◽  
Author(s):  
B. Kim ◽  
M. Gautier ◽  
G. Olvera Palma ◽  
P. Molle ◽  
P. Michel ◽  
...  

The aim of this study was to characterize the efficiency of an intensified process of vertical flow constructed wetland having the following particularities: (i) biological pretreatment by trickling filter, (ii) FeCl3 injection for dissolved phosphorus removal and (iii) succession of different levels of redox conditions along the process line. A pilot-scale set-up designed to simulate a real-scale plant was constructed and operated using real wastewater. The influences of FeCl3 injection and water saturation level within the vertical flow constructed wetland stage on treatment performances were studied. Three different water saturation levels were compared by monitoring: suspended solids (SS), total phosphorus (TP), dissolved chemical oxygen demand (COD), ammonium, nitrate, phosphate, iron, and manganese. The results confirmed the good overall efficiency of the process and the contribution of the trickling filter pretreatment to COD removal and nitrification. The effects of water saturation level and FeCl3 injection on phosphorus removal were evaluated by analysis of the correlations between the variables. Under unsaturated conditions, good nitrification and no denitrification were observed. Under partly saturated conditions, both nitrification and denitrification were obtained, along with a good retention of SSs. Finally, under saturated conditions, the performance was decreased for almost all parameters.


2017 ◽  
Vol 77 (4) ◽  
pp. 988-998 ◽  
Author(s):  
Tadesse Alemu ◽  
Andualem Mekonnen ◽  
Seyoum Leta

Abstract In the present study, a pilot scale horizontal subsurface flow constructed wetland (CW) system planted with Phragmites karka; longitudinal profile was studied. The wetland was fed with tannery wastewater, pretreated in a two-stage anaerobic digester followed by a sequence batch reactor. Samples from each CW were taken and analyzed using standard methods. The removal efficiency of the CW system in terms of biological oxygen demand (BOD), chemical oxygen demand (COD), Cr and total coliforms were 91.3%, 90%, 97.3% and 99%, respectively. The removal efficiency for TN, NO3− and NH4+-N were 77.7%, 66.3% and 67.7%, respectively. Similarly, the removal efficiency of SO42−, S2− and total suspended solids (TSS) were 71.8%, 88.7% and 81.2%, respectively. The concentration of COD, BOD, TN, NO3−N, NH4+-N, SO42 and S2− in the final treated effluent were 113.2 ± 52, 56 ± 18, 49.3 ± 13, 22.75 ± 20, 17.1 ± 6.75, 88 ± 120 and 0.4 ± 0.44 mg/L, respectively. Pollutants removal was decreased in the first 12 m and increased along the CW cells. P. karka development in the first cell of CW was poor, small in size and experiencing chlorosis, but clogging was higher in this area due to high organic matter settling, causing a partial surface flow. The performance of the pilot CW as a tertiary treatment showed that the effluent meets the permissible discharge standards.


2003 ◽  
Vol 48 (5) ◽  
pp. 257-266 ◽  
Author(s):  
K. Boonsong ◽  
S. Piyatiratitivorakul ◽  
P. Patanaponpaiboon

The study evaluated the possibility of using mangrove plantation to treat municipal wastewater. Two types of pilot scale (100 × 150 m2) free water surface constructed wetland were set up. One system was a natural Avicennia marina dominated forest system. The other system was a newly planted system in which seedlings of Rhizophora spp., A. marina, Bruguiera cylindrica and Ceriops tagal were planted in 4 strips. Municipal wastewater was retained within the systems for 7 and 3 days, respectively. The results indicated that the average removal percentage of TSS, BOD, NO3-N, NH4-N, TN, PO4-P and TP in the newly planted system were 27.6-77.1, 43.9-53.9, 37.6-47.5, 81.1-85.9, 44.8-54.4, 24.7-76.8 and 22.6-65.3, respectively. Whereas the removal percentage of those parameters in the natural forest system were 17.1-65.9, 49.5-51.1, 44.0-60.9, 51.1-83.5, 43.4-50.4, 28.7-58.9 and 28.3-48.0, respectively. Generally, the removal percentages within the newly planted system and the natural forest system were not significantly different. However, when the removal percentages were compared with detention time, TSS, PO4-P and TP percentages removed were significantly higher in the 7-day detention time treatment. Even though the removal percentages were highly varied and temporally dependent, the overall results showed that mangrove plantation could be used as constructed wetland for municipal wastewater treatment in a similar way to the natural mangrove system.


2019 ◽  
Vol 80 (6) ◽  
pp. 1145-1154
Author(s):  
Agyemang Richard Osei ◽  
Yacouba Konate ◽  
Felix Kofi Abagale

Abstract Constructed wetland technology is an innovative engineering technique for faecal sludge (FS) management. The presence of emergent macrophytes enhances the important processes of evapotranspiration, sludge mineralisation, and contaminant reduction. Consequently, selecting a species that can withstand the difficult sludge contaminated conditions within a local context is vital. This study monitored the pollutant removal potentials and growth dynamics of Bambusa vulgaris and Cymbopogon nardus as promising macrophytes for the constructed wetland technology in the Sudano-Sahelian context. The experiment, at pilot scale, consisted of plastic reactors (27 litre) filled with filter media of sand and fine gravels at the base, and planted with the selected species. Pollutant removal efficiencies were evaluated based on differences between influent and effluent concentrations, and physiological growth parameters of plant height, number of leaves and number of plants were monitored monthly. Total annual sludge loading rate of 31.4 and 103.4 kg TS/(m2·yr) (TS: total solids) were determined for FS + wastewater (acclimatisation phase) and FS load respectively. Both species recorded appreciable pollutant removal efficiency >80% for the organic (chemical oxygen demand), nutrients (PO43_P and NH4-N) and solid (total suspended solids and total volatile solids) contents. The species thus demonstrated satisfactory performance of resistance for faecal polluted wetland conditions.


2008 ◽  
Vol 58 (6) ◽  
pp. 1237-1243
Author(s):  
Gregor D. Zupanèiè ◽  
Viktor Grilc ◽  
Milenko Roš ◽  
Nataša Uranjek-Ževart

An autothermal aerobic sequencing batch process for sludge digestion and “class A” biosolids production was developed. The process was tested in laboratory and pilot scale size up to 150 PE, which can be considered a full scale size in some cases. In this process the maximum temperatures of 61.2°C and 60.2°C were achieved in laboratory scale in pilot scale equipment, respectively. The degradation efficiency of total chemical oxygen demand of sludge was between 50 and 70%. Similar results were achieved using pure oxygen in laboratory scale and oxygen/air mixture 1:1 by volume. The reactor scale greatly affects the achievement of thermophilic temperature. In smaller sizes the convective heat losses are the prevailing heat sink and the process is unable to produce enough heat to reach thermophilic temperature. Larger systems produce excess heat and can be installed with less intense aeration systems. The limit of air aeration system is at the size of about 500 PE.


2014 ◽  
Vol 69 (7) ◽  
pp. 1410-1418 ◽  
Author(s):  
Weijie Guo ◽  
Zhu Li ◽  
Shuiping Cheng ◽  
Wei Liang ◽  
Feng He ◽  
...  

To examine the performance of a constructed wetland system on stormwater runoff and domestic sewage (SRS) treatment in central east China, two parallel pilot-scale integrated constructed wetland (ICW) systems were operated for one year. Each ICW consisted of a down-flow bed, an up-flow bed and a horizontal subsurface flow bed. The average removal rates of chemical oxygen demand (CODCr), total suspended solids (TSS), ammonia (NH4+-N), total nitrogen (TN) and total phosphorus (TP) were 63.6, 91.9, 38.7, 43.0 and 70.0%, respectively, and the corresponding amounts of pollutant retention were approximately 368.3, 284.9, 23.2, 44.6 and 5.9 g m−2 yr−1, respectively. High hydraulic loading rate (HLR) of 200 mm/d and low water temperatures (<15 °C) resulted in significant decrease in removals for TP and NH4+-N, but had no significant effects on removals of COD and TSS. These results indicated that the operation of this ICW at higher HLR (200 mm/d) might be effective and feasible for TSS and COD removal, but for acceptable removal efficiencies of nitrogen and phosphorus it should be operated at lower HLR (100 mm/d). This kind of ICW could be employed as an effective technique for SRS treatment.


Author(s):  
Maria Cristina Collivignarelli ◽  
Marco Carnevale Miino ◽  
Franco Hernan Gomez ◽  
Vincenzo Torretta ◽  
Elena Cristina Rada ◽  
...  

In the coming years, water stress is destined to worsen considering that the consumption of water is expected to increase significantly, and climate change is expected to become more evident. Greywater (GW) has been studied as an alternative water source in arid and semiarid zones. Although there is no single optimal solution in order to treat GW, constructed wetlands proved to be effective. In this paper, the results of the treatment of a real GW by a horizontal flow constructed wetland (HFCW) for more than four months are shown. In the preliminary laboratory-scale plant, Phragmites australis, Carex oshimensis and Cyperus papyrus were tested separately and showed very similar results. In the second phase, pilot-scale tests were conducted to confirm the performance at a larger scale and evaluate the influence of hydraulic retention time, obtaining very high removal yields on turbidity (>92%), total suspended solids (TSS) (>85%), chemical oxygen demand (COD) (>89%), and five-day biological oxygen demand (BOD5) (>88%). Based on the results of the pilot-scale HFCW, a comparison with international recommendations by World Health Organization and European Union is discussed.


Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 374
Author(s):  
Hongbo Feng ◽  
Honggang Yang ◽  
Jianlong Sheng ◽  
Zengrui Pan ◽  
Jun Li

Aerobic granular sludge (AGS) with oversized diameter commonly affects its stability and pollutant removal. In order to effectively restrict the particle size of AGS, a sequencing batch reactor (SBR) with a spiny aeration device was put forward. A conventional SBR (R1) and an SBR (R2) with the spiny aeration device treating tannery wastewater were compared in the laboratory. The result indicates that the size of the granular sludge from R2 was smaller than that from R1 with sludge granulation. The spines and air bubbles could effectively restrict the particle size of AGS by collision and abrasion. Nevertheless, there was no significant change in mixed liquor suspended solids (MLSS) and the sludge volume index (SVI) in either bioreactors. The removal (%) of chemical oxygen demand (COD) and ammonia nitrogen (NH4+-N) in these two bioreactors did not differ from each other greatly. The analysis of biological composition displays that the proportion of Proteobacteria decreased slightly in R2. The X-ray fluorescence (XRF) analysis revealed less accumulation of Fe and Ca in smaller granules. Furthermore, a pilot-scale SBR with a spiny aeration device was successfully utilized to restrict the diameter of granules at about 300 μm.


2000 ◽  
Vol 42 (1-2) ◽  
pp. 263-268 ◽  
Author(s):  
R. Messalem ◽  
A. Brenner ◽  
S. Shandalov ◽  
Y. Leroux ◽  
P. Uzlaner ◽  
...  

In Israel the shortage of water and concern for the quality of groundwater resources have led to an awareness that a national wastewater reclamation program must be developed. Such a program could cover a major part of the agricultural water demand and could facilitate disposal of effluents without health hazards or environmental problems. A two-stage pilot-scale system comprising secondary sequencing batch reactor (SBR) treatment and tertiary microfiltration was operated for the treatment of Beer-Sheva municipal wastewater. The self-cleaning, continuous microfiltration system comprised a filter module made up of hollow fiber microporous membranes, with a pore size distribution of less than 0.1 μm, encapsulated into a bundle. The unit, which has a nominal filtration area of 4 m2, can treat 4–5 m3 of sewage per day, at a nominal rate of about 500 L/h. SBR treatment of the raw sewage produced an effluent with a biochemical oxygen demand (BOD) of <20 mg/L and total suspended solids (TSS) of <20 mg/L. Further treatment by microfiltration resulted in a BOD <5 mg/L, TSS <1 mg/L and turbidity <0.2 nephelometric turbidity units (NTU). Bacterial counts showed 6-log removal of coliforms and fecal coliforms. These results indicate that the two-stage scheme is capable of producing an effluent that meets or even surpasses the requirements for unrestricted water reuse for agriculture.


Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 2007
Author(s):  
Qijun Ni ◽  
Tao Wang ◽  
Jialin Liao ◽  
Wansheng Shi ◽  
Zhenxing Huang ◽  
...  

In this study, pilot-scale vertical-flow constructed wetland (VFCW) and horizontal-flow constructed wetland (HFCW) were constructed to treat eutrophic water, and dissolved oxygen (DO) distributions, decontamination performances and key enzymes activities were compared under different influent loads. The influent load increase caused reductions of DO levels and removal efficiencies of chemical oxygen demand (COD), total nitrogen (TN), NH4+−N and organic nitrogen, but it had no remarkable effect on the removal of NO3−−N and total phosphorus (TP). The interior DO concentrations of VFCW were higher than those of HFCW, indicating a vertical hydraulic flow pattern was more conducive to atmospheric reoxygenation. The VFCW and HFCW ecosystems possessed comparable removal capacities for TN, NO3−−N and TP. VFCW had a remarkable superiority for COD and organic nitrogen degradation, but its effluent NH4+−N concentration was higher, indicating the NH4+−N produced from organic nitrogen degradation was not effectively further removed in the VFCW system. The activities of protease, urease and phosphatase declined with the increasing depth of substrate layers, and they were positively correlated with DO concentrations. The enzymatic activities of VFCW were significantly higher than that of HFCW in the upper layers. Taken together, VFCW and HFCW presented a certain difference in operational properties due to the different hydraulic flow patterns.


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