scholarly journals Potential of integrated vertical and horizontal flow constructed wetland with native plants for sewage treatment under different hydraulic loading rates

2017 ◽  
Vol 76 (2) ◽  
pp. 434-442 ◽  
Author(s):  
Xuan Cuong Nguyen ◽  
Dinh Duc Nguyen ◽  
Nguyen Thi Loan ◽  
Soon Woong Chang

In this study, a pilot-scale integrated constructed wetland with vertical flow (VF) and horizontal flow (HF) in series was designed and investigated to evaluate sewage wastewater treatment capacity. The VF unit was planted with Canna indica and was 1.2 m long, 1.2 m wide, and 1.2 m high; whereas the HF unit contained Colocasia esculenta and was 3.0 m long, 1.0 m wide, and 1.0 m high. The system was operated under different hydraulic loading rates (HLRs) of 0.1, 0.2, and 0.15 m/d. The effluent concentrations differed as HLR changed, and the means were total suspended solids (TSS): 87 mg/L; biological oxygen demand (BOD5): 31 mg/L; chemical oxygen demand (CODCr): 59 mg/L; ammonium nitrogen (NH4-N): 5.3 mg/L; nitrate nitrogen NO3-N: 8.4 mg/L; total nitrogen (TN): 7.1 mg/L; phosphate (PO4-P): 0.9 mg/L; and total coliforms (TCol): 1,485 most probable number (MPN)/100 mL. The average removal efficiencies for TSS, BOD5, TN, NH4-N, PO4-P, and TCol were 28.3, 74.9, 79, 76.2, 3.6, and 82%, respectively. There were significant differences in the effluent concentrations among the three HLRs (P < 0.05), except for PO4-P.

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.


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.


2016 ◽  
Vol 6 (1) ◽  
pp. 115-120 ◽  
Author(s):  
Khalid Muzamil Gani ◽  
Muntjeer Ali ◽  
Ankur Rajpal ◽  
Hitesh Jaiswal ◽  
Absar Ahmad Kazmi

Moving bed biofilm reactor based sewage treatment plants (STPs) have been installed in northern India over the last decade. As such, there are no performance evaluation studies of this technology in the region. Evaluation of four such STPs was carried out in terms of removal efficiencies of physico-chemical parameters, microbiological parameters and heavy metals. Results showed that the average chemical oxygen demand, biological oxygen demand, total suspended solids, total nitrogen and total phosphorus removal of all STPs ranged from 74 to 91%, 81 to 95%, 79 to 93%, 44 to 80% and 58 to 85%, respectively. Total and thermotolerant (faecal) coliform in the influent and effluent of STPs ranged from 1.5 × 104 to 9.3 × 107 most probable number (MPN)/100 mL and 0 MPN/mL to 2,400 MPN/mL, respectively. Heavy metal concentration (nickel, zinc, cadmium, iron, lead, chromium, and copper) in effluent samples of all the STPs was below Indian discharge limits except lead. Integrated efficiency (IE) of the STPs was also evaluated and the results showed that the actual IE of all STPs was 0–10% larger than standard IE, indicating the suitability of the technology in the region.


2011 ◽  
Vol 1 (2) ◽  
pp. 144-151 ◽  
Author(s):  
C. W. Maina ◽  
B. M. Mutua ◽  
S. O. Oduor

The discharge of untreated wastewater or partially treated effluent and runoff from agricultural fields into water bodies is a major source of surface water pollution worldwide. To mitigate this problem, wastewater treatment using wastewater stabilization ponds and constructed wetlands have been promoted. The performance of such wastewater treatment systems is strongly dependent on their hydraulics, which if not properly considered during design or operation, may result in the partially treated effluent being discharged into water bodies. This paper presents results from a study that was carried out to evaluate the performance of a vertical flow constructed wetland system under varying hydraulic loading regimes. The influent and effluent samples from the constructed wetland were collected and analysed for physical, chemical and biological parameters of importance to water quality based on recommended standard laboratory methods. The data collected was useful in determining the treatment efficiency of the wetland. The hydraulic loading rate applied ranged between 0.014 and 0.174 m/day. Phosphorus reduction for the different hydraulic loading rates ranged between 92 and 47% for lowest and highest loading rates applied respectively. However, ammonium nitrogen reduction was not significantly affected by the different hydraulic loading rates, since the reduction ranged between 97 and 94%.


Author(s):  
Delvio Sandri ◽  
Ana Paula Reis

The objective is to assess the initial performance of a constructed wetland system and the development of the macrophyte species cattail(Typha spp.) (CWt), piripiri (Cyperus giganteus) (CWp), and white garland lily (Hedychium coronarium Koehne) (CWl) and an suncultivated (UNc) on the treatment of sewage from toilets and from a restaurant. Changes in hydrogen potential, electrical conductivity, total suspended solids, total solids, biochemical oxygen demand, chemical oxygen demand, turbidity, nitrate, ammonium nitrogen, total phosphate, hydraulic retention time (HRT), and potential evapotranspiration (PET) and the development and adaptation of macrophytes were measured. The surface area of ??each constructed wetland (CW) had a surface area of 16.25 m2 and average volume treated of 0.40 m3 d-1, with continuous variable horizontal subsurface flow equally fed with sewage previously treated in three septic tanks in series, with an individual useful volume of 5.100 L. The PET in CWt, CWp and CWl was higher than that of UNc. The highest pH values were obtained in the effluent of CWp, CWt, and CWl. The use of macrophytes did not influence the EC, TS, BOD5,20, COD, and nitrate were lower and ammonium nitrogen and total phosphate were higher in the effluent of CWs and UNc in relation to the influent. The efficiency indexes that showed a very strong Pearson correlations (> 90%) were pH correlated with N-NH4+, turbidity correlated with COD, TS correlated with EC, and BOD5,20 and COD correlated with NO3-.Piripiri and cattails showed the best development of plants in the second half of CW.


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.


2018 ◽  
Vol 78 (1) ◽  
pp. 49-56
Author(s):  
I. A. Sánchez ◽  
R. K. X. Bastos ◽  
E. A. T. Lana

Abstract In two pilot-scale experiments, fingerlings and juvenile of tilapia were reared in high rate algal pond (HRAP) effluent. The combination of three different total ammonia nitrogen (TAN) surface loading rates (SLR1 = 0.6, SLR2 = 1.2; SLR3 = 2.4 kg TAN·ha−1·d−1) and two fish stocking densities (D1 = 4 and D2 = 8 fish per tank) was evaluated during two 12-week experiments. Fingerlings total weight gain varied from 4.9 to 18.9 g, with the highest value (equivalent to 0.225 g·d−1) being recorded in SLR2-D1 treatment; however, high mortality (up to 67%) was recorded, probably due to sensitivity to ammonia and wide daily temperature variations. At lower water temperatures, juvenile tilapia showed no mortality, but very low weight gain. The fish rearing tanks worked as wastewater polishing units, adding the following approximate average removal figures on top of those achieved at the HRAP: 63% of total Kjeldahl nitrogen; 54% of ammonia nitrogen; 42% of total phosphorus; 37% of chemical oxygen demand; 1.1 log units of Escherichia coli.


2013 ◽  
Vol 69 (2) ◽  
pp. 269-277 ◽  
Author(s):  
C. Da Ros ◽  
C. Cavinato ◽  
F. Cecchi ◽  
D. Bolzonella

In this study the anaerobic co-digestion of wine lees together with waste activated sludge in mesophilic and thermophilic conditions was tested at pilot scale. Three organic loading rates (OLRs 2.8, 3.3 and 4.5 kgCOD/m3d) and hydraulic retention times (HRTs 21, 19 and 16 days) were applied to the reactors, in order to evaluate the best operational conditions for the maximization of the biogas yields. The addition of lee to sludge determined a higher biogas production: the best yield obtained was 0.40 Nm3biogas/kgCODfed. Because of the high presence of soluble chemical oxygen demand (COD) and polyphenols in wine lees, the best results in terms of yields and process stability were obtained when applying the lowest of the three organic loading rates tested together with mesophilic conditions.


Author(s):  
Felipe Tiago do Nascimento ◽  
Carlos Augusto do Nascimento ◽  
Fernando Rosado Spilki ◽  
Rodrigo Staggemeier ◽  
Cláudio Marcos Lauer Júnior

Natural water distillation can destroy and/or inactivate microorganisms that are sensitive to heat and ultraviolet radiation (UV). This method is currently used to provide fresh water in ships and in the desalination of brackish water. For the development of this research, a pilot-scale solar still was built and installed in the southern region of Brazil, in order to assess its efficiency in water disinfection, which was based on the most probable number (MPN) of total coliforms and  Escherichia coli, in addition to the DNA copy number of human adenovirus type 5 (HAdV-5) in raw, undistilled samples and in treated distilled water. Results showed that the distillation process removed 100% of total coliform and Escherichia coli and 4.5 log (99.997%) of HAdV-5, which meets the microbiological standards for drinking water according to national Brazilian regulations, as well as USEPA and HEALTH CANADA requirements.


Sign in / Sign up

Export Citation Format

Share Document