Biogeochemical indicators to evaluate pollutant removal efficiency in constructed wetlands

1997 ◽  
Vol 35 (5) ◽  
pp. 1-10 ◽  
Author(s):  
K. R. Reddy ◽  
E. M. D'Angelo
Keyword(s):  
Microbial Biomass ◽  
Removal Efficiency ◽  
Nitrate Removal ◽  
Oxygen Demand ◽  
Acid Soils ◽  
Pollutant Removal ◽  
Alkaline Soils ◽  
Organic C ◽  
Wetland Treatment ◽  
Biogeochemical Indicators

Wetlands support several aerobic and anaerobic biogeochemical processes that regulate removal/retention of pollutants, which has encouraged the intentional use of wetlands for pollutant abatement. The purpose of this paper is to present a brief review of key processes regulating pollutant removal and identify potential indicators that can be measured to evaluate treatment efficiency. Carbon and toxic organic compound removal efficiency can be determined by measuring soil or water oxygen demand, microbial biomass, soil Eh and pH. Similarly, nitrate removal can be predicted by dissolved organic C and microbial biomass. Phosphorus retention can be described by the availability of reactive Fe and Al in acid soils and Ca and Mg in alkaline soils. Relationships between soil processes and indicators are useful tools to transfer mechanistic information between diverse types of wetland treatment systems.

Retention and nitrification of injected anhydrous NH3as affected by soil pH

2012 ◽  
Vol 92 (4) ◽  
pp. 589-598 ◽  
Author(s):  
Mônica B. Benke ◽  
Tee Boon Goh ◽  
Rigas Karamanos ◽  
Newton Z. Lupwayi ◽  
Xiying Hao
Keyword(s):  
Soil Properties ◽  
Soil Ph ◽  
Acid Soils ◽  
Field Capacity ◽  
Alkaline Soils ◽  
Canadian Prairie ◽  
Agronomic Efficiency ◽  
Total N ◽  
Organic C ◽  
Prairie Soils

Benke, M. B., Goh, T. B., Karamanos, R., Lupwayi, N. Z. and Hao, X. 2012. Retention and nitrification of injected anhydrous NH3as affected by soil pH. Can. J. Soil Sci. 92: 589–598. Anhydrous ammonia is an economical and extensively used fertilizer, yet loss after injection can reduce its agronomic efficiency. A laboratory experiment was conducted to examine how soil properties affect ammonia retention and nitrification following anhydrous NH3injection using 10 different Canadian prairie soils. Soils were also injected with atmospheric air for comparison. Following injection, soils were incubated for up to 216 h at field capacity. Among the soil properties studied [pH (1:2 water), clay, total N, and organic C contents], only pH was negatively related (R2=0.55, n=10, 24 h incubation) to percentage injected N retained by soil. The amount of N retained by soil 24 h following injection was 92±2% (mean±SEM) when pH <6, compared with 64±2% when pH>7.5. Rate of nitrification increased (P<0.001) about 48–96 h following injection and was greater in pH>7.5 than pH<6 soils. There was no difference (P>0.05) in bacterial diversity between ammonia- and air-injected soils. The slower nitrification rates suggest that potential leaching and denitrification losses in acid soils could be smaller than in alkaline soils.

Influence of polyphenols on low-loaded synthetic winery wastewater constructed wetland treatment with different plant speciesA paper submitted to the Journal of Environmental Engineering and Science.

2009 ◽  
Vol 36 (4) ◽  
pp. 690-700 ◽  
Author(s):  
J. Mena ◽  
R. Gómez ◽  
J. Villaseñor ◽  
A. de Lucas
Keyword(s):  
Analysis Of Variance ◽  
Oxygen Demand ◽  
Experimental Period ◽  
Pilot Scale ◽  
Lythrum Salicaria ◽  
Pollutant Removal ◽  
Synthetic Wastewater ◽  
Bulk Liquid ◽  
Wetland Treatment ◽  
Removal Efficiencies

Synthetic wastewaters simulating physically pre-treated low-loaded winery effluents were treated for four months with five pilot-scale horizontal subsurface flow constructed wetlands (HSSF-CWs) using different plants. Species under study were Phragmites australis (HSSF-CW2), Lythrum salicaria (HSSF-CW3), Cladium mariscus (HSSF-CW4), and Iris pseudacorus (HSSF-CW5). The designation HSSF-CW1 was not planted, and was used as a control. The mean dissolved oxygen and oxidation–reduction potential values in all HSSF-CWs indicated anaerobic conditions in the bulk liquid. High pollutant-removal efficiencies were obtained. Apparently, the species with higher growth (Phragmites, Lythrum, and particularly Iris) improved total nitrogen (TN) and nitrogen as ammonium (N-NH4+) removals, but adversely affected sulphate (SO42–) anaerobic reduction. Chemical oxygen demand (COD) removal efficiencies were high, although there were no clear indications how the kinds of plants might have influenced this parameter. A statistical analysis of variance indicated that only N-NH4+ removal efficiencies were statistically different owing to the influence of the different plants. In a second 6 month experimental period, polyphenols (13 mg L–1) were added to the synthetic wastewater to study possible inhibition effects. The addition of polyphenols did not seem to cause inhibition effects on COD, TN, and N-NH4+ removals, but clearly negatively affected SO42– removal. A new two-way analysis of variance confirmed that only SO42– removal was negatively affected by polyphenols, while the effects of the different plants were only significant for N-NH4+ removal. Polyphenols were nearly completely removed. First order rate constants obtained for COD, TN, SO42–, and polyphenol removals were similar to those reported by other authors.

scholarly journals UV Light-Irradiated Photocatalytic Degradation of Coffee Processing Wastewater Using TiO2 as a Catalyst

Environments ◽  
2020 ◽  
Vol 7 (6) ◽  
pp. 47 ◽  
Author(s):  
Gurudev Sujatha ◽  
Subramaniam Shanthakumar ◽  
Fulvia Chiampo
Keyword(s):  
Photocatalytic Degradation ◽  
Removal Efficiency ◽  
Photocatalytic Oxidation ◽  
Uv Light ◽  
Oxygen Demand ◽  
Pollutant Removal ◽  
Ultraviolet C ◽  
Catalyst Dosage ◽  
Uv C ◽  
Experimental Runs

The coffee industry generates a significant amount of wastewater that is rich in organic loads and is highly acidic. The present study investigates the potential of the heterogeneous photocatalytic oxidation process to reduce the pollutant load in coffee processing wastewater. The experimental runs were conducted to evaluate the effect of operative parameters such as pH, catalyst dosage, intensity of UV light irradiation, and addition of oxidant on Chemical Oxygen Demand (COD) and colour reduction. Significant results for COD and colour removal, 67%, and 70% respectively, were achieved at a pH of 4 with titanium dioxide (TiO2), and a catalyst dosage of 500 mg/L, using four ultraviolet-C (UV-C) lamps of 16 W each. With the addition of hydrogen peroxide (H2O2) as an oxidant, the removal efficiency increased to 84% and 75% for COD and colour, respectively. Finally, the best results obtained by photocatalytic degradation using UV light were compared to those using solar light. Based on the investigation, it was inferred that the pollutant removal efficiency in coffee pulping wastewater was also considerably high under sunlight. These findings may have relevance in terms of application in countries where coffee processing is carried out and where sunlight irradiance is usually strong: the technique could be exploited to decrease the pollutant content of this wastewater sustainably.

scholarly journals Responses of Periphyton Microbial Growth, Activity, and Pollutant Removal Efficiency to Cu Exposure

2020 ◽  
Vol 17 (3) ◽  
pp. 941
Author(s):  
Wei Zhong ◽  
Weiqun Zhao ◽  
Jianhui Song
Keyword(s):  
Removal Efficiency ◽  
Microbial Growth ◽  
Oxygen Demand ◽  
Pollutant Removal ◽  
Carbon Source Utilization ◽  
Functional Responses ◽  
Growth Activity ◽  
Underlying Mechanisms ◽  
Microbial Metabolic Activity ◽  
Pollutant Removal Efficiency

Periphyton is an effective matrix for the removal of pollutants in wastewater and has been considered a promising method of bioremediation. However, it still needs to be verified whether periphyton can maintain microbial activity and pollutant removal efficiency when dealing with the influence with complex components, and the underlying mechanisms of periphyton need to be revealed further. Herein, this study investigated the microbial growth, activity and functional responses of periphyton after removal of Cu from wastewater. Results showed that the cultivated periphyton was dominated by filamentous algae, and high Cu removal efficiencies by periphyton were obtained after 108 h treatments. Although 2 mg/L Cu2+ changed the microalgal growth (decreasing the contents of total chlorophyll-a (Chla), the carbon source utilization and microbial metabolic activity in periphyton were not significantly affected and even increased by 2 mg/L Cu2+. Moreover, chemical oxygen demand (COD) removal rates were sustained after 0.5 and 2 mg/L Cu2+ treatments. Our work showed that periphyton had strong tolerance and resistance on Cu stress and is environmentally friendly in dealing with wastewater containing heavy metals, as the microbial functions in pollutant removal could be maintained.

scholarly journals Effect of Ornamental Plants, Seasonality, and Filter Media Material in Fill-and-Drain Constructed Wetlands Treating Rural Community Wastewater

2019 ◽  
Vol 11 (8) ◽  
pp. 2350 ◽  
Author(s):  
Sergio A. Zamora-Castro ◽  
José Luis Marín-Muñiz ◽  
Luis Sandoval ◽  
Monserrat Vidal-Álvarez ◽  
Juan Manuel Carrión-Delgado
Keyword(s):  
Chemical Oxygen Demand ◽  
Removal Efficiency ◽  
Constructed Wetlands ◽  
Ornamental Plants ◽  
Oxygen Demand ◽  
Biomass Productivity ◽  
Pollutant Removal ◽  
Filter Media ◽  
Control Units ◽  
Phosphorous Compounds

The effects of Canna indica (P1), Pontederia sagittata (P2), and Spathiphyllum wallisii (P3) growing in different filter media materials (12 using porous river rock and 12 using tepezyl) on the seasonal removal of pollutants of wastewater using fill-and-drain constructed wetlands (FD-CWs) were investigated during 12 months. Three units of every media were planted with one plant of P1, P2, and P3, and three were kept unplanted. C. indica was the plant with higher growth than the other species, in both filter media. The species with more flower production were: C. indica > P. sagittate > S. wallisii. Reflecting similarly in the biomass of the plants, C. indica and P. sagittata showed more quantity of aerial and below ground biomass productivity than S. wallisii. With respect to the removal efficiency, both porous media were efficient in terms of pollutant removal performance (p > 0.05). However, removal efficiency showed a dependence on ornamental plants. The higher removal of chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total kjeldahl nitrogen (TKN), nitrates (NO3−-N), ammonium (NH4+-N), and phosphates (PO4−3-P) oscillated between 81% to 83%, 80% to 84%, 61% to 69%, 61% to 68%, 65% to 71%, 62% to 68%, and 66% to 69%, respectively, in P1 and P2, removals 15% to 30% higher than P3. The removal in planted microcosms was significantly higher than the unplanted control units (p = 0.023). Nitrogen and phosphorous compounds were highly removed (60%–80%) because in typical CWs, such pollutant removals are usually smaller, indicating the importance of FD-CWs on wastewater treatments using porous river rock and tepezyl as porous filter media. (BOD5), chemical oxygen demand (COD), (NO3−-N), (NH4+-N), (TKN), and (PO4−3-P).

scholarly journals Constructed wetland using corncob charcoal substrate: pollutants removal and intensification

2017 ◽  
Vol 76 (6) ◽  
pp. 1300-1307 ◽  
Author(s):  
Mao Liu ◽  
Boyuan Li ◽  
Yingwen Xue ◽  
Hongyu Wang ◽  
Kai Yang
Keyword(s):  
Removal Efficiency ◽  
Constructed Wetlands ◽  
Oxygen Demand ◽  
Pollutant Removal ◽  
Vertical Flow ◽  
Pollutants Removal ◽  
Denitrification Process ◽  
Better Than ◽  
Potential Substrate ◽  
Stable Stage

To investigate the feasibility of using corncob charcoal substrate in constructed wetlands, four laboratory-scale vertical flow constructed wetlands (VFCWs) were built. Effluent pollutant (chemical oxygen demand (COD), NH4+-N, total phosphorus (TP)) concentrations during the experiment were determined to reveal pollutant removal mechanisms and efficiencies at different stages. In the stable stage, a VFCW using clay ceramisite substrate under aeration attained higher COD (95.1%), and NH4+-N (95.1%) removal efficiencies than a VFCW using corncob charcoal substrate (91.5% COD, 91.3% NH4+-N) under aeration, but lower TP removal efficiency (clay ceramisite 32.0% and corncob charcoal 40.0%). The VFCW with raw corncob substrate showed stronger COD emissions (maximum concentration 3,108 mg/L) than the corncob charcoal substrate (COD was lower than influent). The VFCW using corncob charcoal substrate performed much better than the VFCW using clay ceramisite substrate under aeration when the C/N ratio was low (C/N = 1.5, TN removal efficiency 36.89%, 4.1% respectively). These results suggest that corncob charcoal is a potential substrate in VFCWs under aeration with a unique self –supplying carbon source property in the denitrification process.

Novel application of bamboo-based fibers in a biological contact oxidation process

2014 ◽  
Vol 69 (7) ◽  
pp. 1534-1540 ◽  
Author(s):  
Xiaoming Zou ◽  
Yi Feng ◽  
Changming Sheng ◽  
Jia Liu ◽  
Lijun Lu ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Oxidation Process ◽  
Oxygen Demand ◽  
Specific Area ◽  
Pollutant Removal ◽  
Bamboo Charcoal ◽  
High Accumulation ◽  
Contact Oxidation ◽  
Biofilm Development ◽  
Biological Contact Oxidation

Generally, biofilm-supporting carriers in biological contact oxidation processes are made from thermoplastic polymers, which cause potential ecological damage because of the low biodegradation and high accumulation in organisms. Thus, four bamboo-based fibers, bamboo primitive fiber, bamboo fiber, bamboo charcoal fiber (BBF) and bamboo charcoal–cotton blending fiber (BCBF), were used as carriers and compared with two commercial carriers (vinylon (VY) and polypropylene (PP)) in a biological contact oxidation process system with the goal to develop a biodegradable and sustainable biofilm medium. Under steady state conditions, pollutants (chemical oxygen demand and NH4+-N) in stage 1 (days 1–29, hydraulic retention time (HRT) = 12 h) were efficiently removed with a removal efficiency ranging from 85 to 95%. In stage 2 (days 30–53, HRT = 4–12 h), the pollutant-removal efficiency of four reactors (BBF, BCBF, VY and PP) were nearly indistinguishable and were higher than the two other reactors, especially when the HRT was set at 4 h (days 46–53). Consequently, two optimized bamboo-based fibers (BBF and BCBF) can be developed as biofilm carriers for wastewater treatment in the future. Furthermore, studies demonstrated that the biofilm development difference showed good correlation with their specific area and relative oxygen content but not with their tenacity and antimicrobial activity.

Pollutant removal characteristics of a two-influent-line BNR process performing denitrifying phosphorus removal: role of sludge recycling ratios

2016 ◽  
Vol 74 (10) ◽  
pp. 2474-2482 ◽  
Author(s):  
Hongbo Liu ◽  
Feng Leng ◽  
Piao Chen ◽  
Stephan Kueppers
Keyword(s):  
Removal Efficiency ◽  
Phosphorus Removal ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Pollutant Removal ◽  
Biological Nutrient Removal ◽  
Carbon Utilization ◽  
Denitrifying Phosphorus Removal ◽  
Removal Rates ◽  
Sludge Recycling

This paper studied denitrifying phosphorus removal of a novel two-line biological nutrient removal process treating low strength domestic wastewater under different sludge recycling ratios. Mass balance of intracellular compounds including polyhydroxyvalerate, polyhydroxybutyrate and glycogen was investigated together with total nitrogen (TN) and total phosphorus (TP). Results showed that sludge recycling ratios had a significant influence on the use of organics along bioreactors and 73.6% of the average removal efficiency was obtained when the influent chemical oxygen demand (COD) ranged from 175.9 mgL−1 to 189.9 mgL−1. The process performed better under a sludge recycling ratio of 100% compared to 25% and 50% in terms of ammonia and COD removal rates. Overall, TN removal efficiency for 50% and 100% sludge recycling ratios were 56.4% and 61.9%, respectively, unlike the big gap for carbon utilization and the TP removal rates, indicating that the effect of sludge recycling ratio on the anaerobic compartments had been counteracted by change in the efficiency of other compartments. The higher ratio of sludge recycling was conducive to the removal of TN, not in favor of TP, and less influence on COD. Thus, 25% was considered to be the optimal sludge recycling ratio.

Performance evaluation of package plant for treatment of single household domestic wastewater

2016 ◽  
Vol 11 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Meena Kumari Sharma ◽  
Absar Ahmad Kazmi
Keyword(s):  
Developing Countries ◽  
Removal Efficiency ◽  
Urban Areas ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Post Treatment ◽  
Pollutant Removal ◽  
Septic Tank ◽  
Efficient Technology ◽  
Treated Effluent

This study was carried out to evaluate the performance of an anaerobic packaged onsite system as an alternative to septic tank for the rural and semi-urban areas of developing countries where centralized sewerage facilities are not available. Potential application was identified on the basis of pollutant removal efficiency. The average per-capita wastewater generation was found to be 140 L/person/day with maximum contribution from the kitchen. The average removal efficiency of the system for chemical oxygen demand (COD), biochemical oxygen demand, total suspended solids, total nitrogen, total phosphate and fecal coliform was 70.9 ± 11.8%, 68.7 ± 8.5%, 78.1 ± 4.7%, 20.2 ± 8.4%, 13.8 ± 3.7% and 86.5 ± 1.6%, respectively. Despite a satisfactory performance, the anaerobically-treated effluent did not meet the disposal standards and required subsequent post treatment. An electrochemical reactor with aluminium electrodes, at a potential difference of 12 V, showed appreciable potential for use in actual households as a post treatment option for further removal of the pathogens and COD. The treated domestic wastewater, with electrocoagulation as a post-treatment measure, was successfully reused for non-potable purposes. Therefore, the package system, in conjugation with electrocoagulation process, promises to be a highly efficient technology for the onsite treatment of domestic wastewater in developing countries while facilitating reuse of the treated effluent for various recreational purposes as well as a safe discharge.

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