Deterministic and stochastic aspects of constructed wetland performance and design

1997 ◽  
Vol 35 (5) ◽  
pp. 149-156 ◽  
Author(s):  
Robert H. Kadlec

Potato processing wastewater contains high concentrations of COD, TSS and TKN. A combination of surface flow wetlands, intermittent vertical flow wetlands, ponds and land application has been used for treatment. This engineered natural system balances irrigation requirements, nitrogen supply and seasonal growth patterns to provide effective year-round operation. A first pilot wetland was operated to determine operability, effectiveness, and plant survival at high COD and nitrogen concentrations. A second pilot system of four wetlands in series was operated to obtain design and operating information. Two surface flow wetlands provided TSS and COD reduction, and ammonified the organic nitrogen. Subsequently, nitrification occurred in the vertical flow wetlands, followed by denitrification in a surface flow wetland. The design target was a balanced nitrogen and irrigation supply for application to crops. Winter storage as used to match the crop application period to the growing season. Both pilot projects met design objectives, and a full scale system has begun operation.

1997 ◽  
Vol 35 (5) ◽  
pp. 263-270 ◽  
Author(s):  
Robert H. Kadlec ◽  
Peter S. Burgoon ◽  
Michael E. Henderson

Potato processing wastewater contains high concentrations of COD, TSS and TKN. A combination of surface flow wetlands, intermittent vertical flow wetlands, ponds and land application has been used for treatment. This engineered natural system balances irrigation requirements, nitrogen supply and seasonal growth patterns to provide effective year-round operation. A first pilot wetland was operated to determine operability, effectiveness, and plant survival at high COD and nitrogen concentrations. A second pilot system of four wetlands in series was operated to obtain design and operating information. Two surface flow wetlands provided TSS and COD reduction, and ammonified the organic nitrogen. Subsequently, nitrification occurred in the vertical flow wetlands, followed by denitrification in a surface flow wetland. The design target was a balanced nitrogen and irrigation supply for application to crops. Winter storage was used to match the crop application period to the growing season. Both pilot projects met design objectives, and a full-scale system has begun operation.


2001 ◽  
Vol 44 (10) ◽  
pp. 157-162 ◽  
Author(s):  
C.O. Onyla ◽  
A.M. Uyub ◽  
J.C. Akunna ◽  
N.A. Norulaini ◽  
A.K.M. Omar

Malaysia is essentially an agricultural country and her major polluting effluents have been from agro-based industries of which palm oil and rubber industries together contribute about 80% of the industrial pollution. Palm oil sludge, commonly referred to, as palm oil mill effluent (POME) is brown slurry composed of 4-5% solids, mainly organic, 0.5-1% residual oil, and about 95% water. The effluent also contains high concentrations of organic nitrogen. The technique for the treatment of POME is basically biological, consisting of pond systems, where the organic nitrogen is converted to ammonia, which is subsequently transformed to nitrate, in a process called nitrification. A 15-month monitoring program of a pond system (combined anaerobic, facultative, and aerobic ponds in series) confirmed studies by other authors and POME operators that nitrification in a pond system demands relatively long hydraulic retention time (HRT), which is not easily achieved, due to high production capacity of most factories. Bioaugmentation of POME with mixed culture of nitrifiers (ammonia and nitrite oxidizers) has been identified as an effective tool not only for enhancing nitrification of POME but also for improving quality of POME as source of liquid nitrogen fertilizer for use in the agricultural sector, especially in oil palm plantations. Nitrate is readily absorbable by most plants, although some plants are able to absorb nitrogen in the form of ammoniun. In this study, up to 60% reduction in HRT (or up to 20% reduction in potential land requirement) was achieved when bioaugmentation of POME was carried out with the aim of achieving full nitrification.


2015 ◽  
Vol 71 (9) ◽  
pp. 1333-1339 ◽  
Author(s):  
A. Morvannou ◽  
N. Forquet ◽  
S. Michel ◽  
S. Troesch ◽  
P. Molle

Approximately 3,500 constructed wetlands (CWs) provide raw wastewater treatment in France for small communities (<5,000 people equivalent). Built during the past 30 years, most consist of two vertical flow constructed wetlands (VFCWs) in series (stages). Many configurations exist, with systems associated with horizontal flow filters or waste stabilization ponds, vertical flow with recirculation, partially saturated systems, etc. A database analyzed 10 years earlier on the classical French system summarized the global performances data. This paper provides a similar analysis of performance data from 415 full-scale two-stage VFCWs from an improved database expanded by monitoring data available from Irstea and the French technical department. Trends presented in the first study are confirmed, exhibiting high chemical oxygen demand (COD), total suspended solids (TSS) and total Kjeldahl nitrogen (TKN) removal rates (87%, 93% and 84%, respectively). Typical concentrations at the second-stage outlet are 74 mgCOD L−1, 17 mgTSS L−1 and 11 mgTKN L−1. Pollutant removal performances are summarized in relation to the loads applied at the first treatment stage. While COD and TSS removal rates remain stable over the range of applied loads, the spreading of TKN removal rates increases as applied loads increase.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Thitiwut Vongkampang ◽  
Krishnan Sreenivas ◽  
Jonathan Engvall ◽  
Carl Grey ◽  
Ed W. J. van Niel

Abstract Background Caldicellulosiruptor kronotskyensis has gained interest for its ability to grow on various lignocellulosic biomass. The aim of this study was to investigate the growth profiles of C. kronotskyensis in the presence of mixtures of glucose–xylose. Recently, we characterized a diauxic-like pattern for C. saccharolyticus on lignocellulosic sugar mixtures. In this study, we aimed to investigate further whether C. kronotskyensis has adapted to uptake glucose in the disaccharide form (cellobiose) rather than the monosaccharide (glucose). Results Interestingly, growth of C. kronotskyensis on glucose and xylose mixtures did not display diauxic-like growth patterns. Closer investigation revealed that, in contrast to C. saccharolyticus, C. kronotskyensis does not possess a second uptake system for glucose. Both C. saccharolyticus and C. kronotskyensis share the characteristics of preferring xylose over glucose. Growth on xylose was twice as fast (μmax = 0.57 h−1) as on glucose (μmax = 0.28 h−1). A study of the sugar uptake was made with different glucose–xylose ratios to find a kinetic relationship between the two sugars for transport into the cell. High concentrations of glucose inhibited xylose uptake and vice versa. The inhibition constants were estimated to be KI,glu = 0.01 cmol L−1 and KI,xyl = 0.001 cmol L−1, hence glucose uptake was more severely inhibited by xylose uptake. Bioinformatics analysis could not exclude that C. kronotskyensis possesses more than one transporter for glucose. As a next step it was investigated whether glucose uptake by C. kronotskyensis improved in the form of cellobiose. Indeed, cellobiose is taken up faster than glucose; nevertheless, the growth rate on each sugar remained similar. Conclusions C. kronotskyensis possesses a xylose transporter that might take up glucose at an inferior rate even in the absence of xylose. Alternatively, glucose can be taken up in the form of cellobiose, but growth performance is still inferior to growth on xylose. Therefore, we propose that the catabolism of C. kronotskyensis has adapted more strongly to pentose rather than hexose, thereby having obtained a specific survival edge in thermophilic lignocellulosic degradation communities.


Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1380
Author(s):  
Binfeng Yin ◽  
Xinhua Wan ◽  
Changcheng Qian ◽  
A. S. M. Muhtasim Fuad Sohan ◽  
Teng Zhou ◽  
...  

Metal ions in high concentrations can pollute the marine environment. Human activities and industrial pollution are the causes of Cu2+ contamination. Here, we report our discovery of an enzyme method-based microfluidic that can be used to rapidly detect Cu2+ in seawater. In this method, Cu2+ is reduced to Cu+ to inhibit horseradish peroxidase (HRP) activity, which then results in the color distortion of the reaction solution. The chip provides both naked eye and spectrophotometer modalities. Cu2+ concentrations have an ideal linear relationship, with absorbance values ranging from 3.91 nM to 256 μM. The proposed enzyme method-based microfluidic chip detects Cu2+ with a limit of detection (LOD) of 0.87 nM. Other common metal ions do not affect the operation of the chip. The successful detection of Cu2+ was achieved using three real seawater samples, verifying the ability of the chip in practical applications. Furthermore, the chip realizes the functions of two AND gates in series and has potential practical implementations in biochemical detection and biological computing.


Fermentation ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 313
Author(s):  
Paula Rojas ◽  
Daniel Lopez ◽  
Francisco Ibañez ◽  
Camila Urbina ◽  
Wendy Franco ◽  
...  

Organic nitrogen plays a significant role in the fermentation performance and production of esters and higher alcohols. This study assessed the use of yeast protein hydrolysate (YPH) as a nitrogen source for grape must fermentation. In this study, we prepared an enzymatic protein hydrolysate using yeasts recovered from a previous fermentation of wine. Three treatments were performed. DAP supplementation was used as a control, while two YPH treatments were used. Low (LDH) and high degrees of hydrolysis (HDH), 3.5% and 10%, respectively, were chosen. Gas chromatography and principal component analysis indicated a significant positive influence of YPH-supplementations on the production of esters and higher alcohols. Significantly high concentrations of 3-methyl-1-penthanol, isoamyl alcohol, isobutanol, and 2-phenylethanol were observed. Significant odorant activity was obtained for 3-methyl-1-pentanol and ethyl-2-hexenoate. The use of YPH as nitrogen supplementation is justified as a recycling yeasts technique by the increase in volatile compounds.


2020 ◽  
Vol 36 (6) ◽  
Author(s):  
Itaruã Machri Colla ◽  
Olavo Bilac Quaresma de Oliveira Filho ◽  
Janyeli Dorini Silva de Freitas ◽  
Míria Benetati Delgado Bertéli ◽  
Giani Andrea Linde ◽  
...  

Lentinus crinitus is a medicinal basidiomycete, little studied regarding the basic cultivation conditions, which is used in bioremediation and consumed by native Indians from the Brazilian Amazon. Also, it produces a fungal secondary metabolite panepoxydone that has been described as an essential regulator of the inflammatory and immune response. This study aimed to evaluate basic conditions of temperature, pH, and nitrogen concentration and source in the cultivation of L. crinitus mycelial biomass. In order to evaluate fungal growth temperature, 2% malt extract agar (MEA) medium, pH 5.5, was utilized from 19 to 40 °C. For pH, MEA had pH adjusted from 2 to 11 and cultivated at 28 °C. Urea or soybean meal was added to MEA to obtain final concentration from 0.5 and 16 g/L of nitrogen, pH of 5.5, cultivated at 28 °C. The best temperature growth varies from 31 to 34 ºC and the optimal one is 32.7º C, and the best pH ranges from 4.5 to 6.5 and the optimal one is 6.1. Protein or non-protein nitrogen concentration is inversely proportional to the mycelial biomass growth. Nitrogen concentrations of 2.0 g/L soybean meal and urea inhibit mycelial biomass growth in 11% and 12%, respectively, but high concentrations of 16.0 g/L nitrogen inhibit the growth in 46% and 95%, respectively. The fungus is robust and grows under extreme conditions of temperature and pH, but smaller adaptation with increasing nitrogen concentrations in the cultivation medium, mainly non-protein nitrogen.


2007 ◽  
Vol 386 (1-3) ◽  
pp. 103-113 ◽  
Author(s):  
Jeroen Vandenbruwane ◽  
Stefaan De Neve ◽  
Robert G. Qualls ◽  
Joost Salomez ◽  
Georges Hofman

1961 ◽  
Vol 39 (4) ◽  
pp. 731-738 ◽  
Author(s):  
R. G. Ross

Various elements were tested for their effect on the formation of perithecia of Venturia inaequalis. Apart from nitrogen the elements tested had little effect on the formation of perithecia except at relatively high concentrations. Perithecia did not form in media containing low concentrations of nitrogen and this was influenced by the source of nitrogen and by the cation present in nitrate salts. Perithecial initials developed in higher nitrogen concentrations than perithecia. Nitrogen added 9 weeks after mating of two lines of the fungus prevented the formation of perithecia.Results were difficult to reproduce in a potato-dextrose apple leaf decoction medium but reproducible results were obtained in a synthetic medium.


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