Purification Effect of Constructed Wetland on TN and TP Removal from Eutrophic Wastewater

2011 ◽  
Vol 356-360 ◽  
pp. 2638-2642
Author(s):  
Jun Li Kang

Acorus gramineus Soland., Canna chineresisw, Calla palustris., Rhododendron simsii, Aspidistra elatior and Chamaedorea elegans, were rooted in 0.3m media. The media were composed of 0.15m gravel and 0.15m mixture of sand and soil, and the volume proportion of sand and soil was 2:1. The plants were grown in six 0.5x1.0m concrete ponds that were filled with a further 0.3m of effluent from an oxidation ditch operated in a sequential batch mode, treating eutrophic wastewater from a university. The water was sampled daily for total N and total P and retained for seven days. A control pond devoid of plants was not included. The levels of total P and total N declined to a maximum of 60-77.6% of initial for total P and 86.7-98% for total N within four days. Since levels stayed constant for total N but rose for total P, four day retention would minimize amounts of these nutrients leaving the ponds. The conclusion can be gotten through analysis that the plant’s absorb isn’t the main cause of total N and total P remove for constructed wetland, but there are some effect by the plant adaptability, so in the design process of eutrophic wastewater treatment, plants could be chosen on their aesthetic merits to enhance the wetland system’s sight effect. And the hydraulic residence is better inside 4 days in the surface constructed wetland design process. The mechanisms involved in nutrient decline were not investigated.

2006 ◽  
Vol 53 (3) ◽  
pp. 165-172 ◽  
Author(s):  
K.R. Pagilla ◽  
M. Urgun-Demirtas ◽  
R. Ramani

The USEPA (2001) water quality nutrient criteria will have a significant impact on water pollution control industry due to stringent N and P requirements. This paper presents an update of findings on successful total N (TN) and total P (TP) technologies being implemented at existing wastewater treatment plants (WWTP) to achieve low TN and TP effluents and some key challenges in achieving lower levels. Plants consistently achieving <5 mg TN/L and <0.5 mg TP/L were identified from a worldwide literature search and plant data collection. Technology gaps and research needs to improve successful technologies to achieve very low TN and TP effluents are summarised in this paper. The dissolved and colloidal organic N have been identified as major challenges in achieving very low levels of TN. Technical and economic challenges to achieve very low TP effluents include alkalinity deficiency, high chemical usage, high sludge production and lack of sufficient influent BOD for biological P uptake.


1993 ◽  
Vol 27 (5-6) ◽  
pp. 343-355 ◽  
Author(s):  
H. Draaijer ◽  
A. H. M. Buunen-van Bergen ◽  
E. van't Oever ◽  
A. A. J. C. Schellen

Two full scale projects are described in this paper; these are the Bergambacht wastewater plant (carrousel) and the Terneuzen wastewater plant (Schreiber system). Both plants use a system of intermittent aeration to combine nitrification and denitrification processes. At the Bergambacht plant biological phosphorus removal is carried out by the introduction of the side stream process. At the Terneuzen plant it is carried out by introducing anaerobic periods in the aeration tanks. The objective is to meet the new total nitrogen and phosphorus effluent standards in The Netherlands of resp. 10-15 and 1-2 mg/l. At the Terneuzen wastewater plant the standards could not be reached for total-nitrogen, mainly due to the low BOD to Kj-N ratio of 2:8 in the feed to the aeration tanks. Adjustments are suggested to improve the denitrification rate. At the Bergambacht wastewater plant effluent concentrations of 6 - 7 mg/l total N and 0.3 mg/l total P were achieved.


2005 ◽  
Vol 51 (9) ◽  
pp. 157-164 ◽  
Author(s):  
L. Yang ◽  
C.C. Hu

In this study, two types of industrial wastewater, oil-refining and steel-milling, were selected for investigating their feasibility of treatment by mesocosm constructed wetland systems. The secondly treated effluents from the wastewater treatment plants were directly discharged into the systems controlled at different flow rates. Three wetland mesocosms were installed in the two industries: mesocosms A and B were in the oil refinery, and mesocosm C was in the steel mill. The substratum media used in wetland systems were sand (mesocosm A) and gravel (mesocosms B and C), while the vegetation types selected were reeds (mesocosms A and B) and mixed species of reeds and cattails (mesocosm C). The flow regimes were controlled as free water surface (FWS) and subsurface flow (SSF) for the sand- and gravel-beds, respectively. According to the experimental results, we found that the system treating oil-refining wastewater performed better than that treating steel-milling wastewater learned by comparing the removal efficiencies of COD, total N and total P. In addition, it was found that for oil-refining wastewater treatments, the SSF wetland system (mesocosm B) performed better than FWS (mesocosm A) wetland system when comparing both of their removal of pollutants and growth of vegetation. Besides, the effluents from these two industrial wetland treatment systems might be reclaimed and reused for boiler water, cooling, cleaning and miscellaneous purposes in industries. Further treatments are required if the constructed wetland effluents are thought about being reused for processing in industries.


2008 ◽  
Vol 58 (12) ◽  
pp. 2427-2433 ◽  
Author(s):  
Kaoru Abe ◽  
Michio Komada ◽  
Akihito Ookuma

The effluent from the combined household wastewater treatment facilities used in unsewered areas of Japan is generally high in nitrogen (N) and phosphorus (P). In Japan, environmental quality standards for zinc (Zn) pollution were enacted recently because of the toxicity of Zn to aquatic ecosystems. In 2004 a fallow paddy field at the Koibuchi College of Agriculture and Nutrition was converted into a surface-water-flow constructed wetland (500 m2) to clean the effluent from the combined household wastewater treatment facility of a dormitory (100 residents) before discharge to a pond. We evaluated N and P removal efficiencies and the fate of soluble Zn in the wetland from April 2006 to March 2007. Wetland influent contained an average of 18.3 mg L−1 total N and 1.86 mg L−1 total P. In the effluent from the wetland, average total N concentration was 10.3 mg L−1 and average total P was 0.90 mg L−1. Average removal rates were 0.37 g m−2 d−1 for total N and 0.050 g m−2 d−1 for total P (percentage removal rates of 40% and 48%, respectively). Soluble Zn concentration decreased from 0.041 in the influent to 0.023 mg L−1 after passing through the wetland. The average Zn removal rate during the year was 0.0007 g m−2 d−1 (percentage removal rate 37%).


1997 ◽  
Vol 35 (5) ◽  
pp. 307-314 ◽  
Author(s):  
Andreas Schönborn ◽  
Brigitta Züst ◽  
Evelyn Underwood

The human waste concept of the Centre for Applied Ecology Schattweid, Switzerland combines treatment of feces in compost toilets and a constructed wetland for the liquid wastes. The wastewater of 5.1 population equivalents (greywater and urine) is treated in a two chambered settling tank followed by an underground vertical flow sand filter and a horizontal flow constructed wetland. The wastewater system has been in operation since 1985. Its performance has been monitored on COD, NH4-N, NO3-N, NO2-N, Total-P and Total-N almost monthly since then, and on other parameters (Total-Fe, Cl) occasionally. COD elimination (91.4 %) and Total-P removal (90.6%) were stable over the years, whereas NH4-N and Total-N elimination have improved markedly from around 55% to 93.0% (NH4-N) and 80.0% (Total-N). Performance in winter was excellent. The addition of an easily degradable carbon source to the plant filter in summer 1991 led to a markedly decreased phosphorus retention and a washout of iron during the experiment.


Author(s):  
Trần Thanh Đức

This research carried out in Huong Vinh commune, Huong Tra town, Thua Thien Hue province aimed to identify types of land use and soil characteristics. Results showed that five crops are found in Huong Vinh commune including rice, peanut, sweet potato, cassava and vegetable. There are two major soil orders with four soil suborders classified by FAO in Huong Vinh commune including Fluvisols (Dystric Fluvisols<em>, </em>Gleyic Fluvisols and Cambic Fluvisols) and Arenosols (Haplic Arenosols). The results from soil analysis showed that three soil suborders including Dystric Fluvisols<em>, </em>Gleyic Fluvisols and Cambic Fluvisols belonging to Fluvisols were clay loam in texture, low pH, low in OC, total N, total P<sub>2</sub>O<sub>5</sub> and total K<sub>2</sub>O. Meanwhile, the Haplic Arenosols was loamy sand in texture, poor capacity to hold OC, total N, total P<sub>2</sub>O<sub>5</sub> and total K<sub>2</sub>O


1986 ◽  
Vol 18 (7-8) ◽  
pp. 289-296
Author(s):  
C. F. Ouyang ◽  
T. J. Wan

This study investigated and compared the treatment characteristics of three different kinds of biological wastewater treatment plants (including rotating biological contactor, trickling filter and oxidation ditch) which are currently operated in Taiwan. The field investigation of this study concentrated on the following items: the performance of biological oxygen demand (BOD) and suspended solids (SS) removal; the sludge yield rate of BOD removal; the settleability of sludge solids; the properties of sludge thickening; the power consumption and land area requirement per unit volume of wastewater. Finally, based on the results of the field investigation, a comparison of the treatment characteristics of the three different biological treatment processes was evaluated.


1997 ◽  
Vol 36 (1) ◽  
pp. 129-137 ◽  
Author(s):  
Vibeke R. Borregaard

In the upgrade of wastewater treatment plants to include biological nutrient removal the space available is often a limiting facor. It may be difficult to use conventional suspended growth processes (i.e. activated sludge) owing to the relatively large surface area required for these processes. Recent years have therefore seen a revived interest in treatment technologies using various types of attached growth processes. The “new” attached growth processes, like the Biostyr process, utilise various kinds of manufactured media, e.g. polystyrene granules, which offer a high specific surface area, and are therefore very compact. The Biostyr plants allow a combination of nitrification-denitrification and filtration in one and the same unit. The results obtained are 8 mg total N/l and an SS content normally below 10 mg/l. The plants in Denmark which have been extended with a Biostyr unit have various levels of PLC control and on-line instrumentation.


2005 ◽  
Vol 65 (1) ◽  
pp. 141-157 ◽  
Author(s):  
J. J. Ramírez ◽  
C. E. M. Bicudo

The vertical and diurnal variation of nitrogen and phosphorus forms, as well as that of soluble reactive silica (SRS), were studied in four sampling days at Garças reservoir, a shallow tropical one located in the city of São Paulo, in southeastern Brazil. Except for N-NH4, all other inorganic forms of nitrogen (N-NO2, N-NO3, and total N) demonstrated decreased concentrations toward the bottom of reservoir. Similarly, all showed significant diurnal differences on every sampling day, with increased values during the night due to absence of photosynthetic assimilation during that period. In the sampling days, these forms decreased on the spring sampling day due to the bloom of Microcystis registered during this period of the year. All three forms of phosphorus (SRP, particulate P, and total P) showed significant vertical variation, except on the fall sampling day. On the summer sampling day there was an increase of both total P and particulate P, the latter because it constitutes more than 70% of the total P during all sampling days. Hourly phosphorus variation was significant during all sampling days, except for the summer one. The SRS vertical variation was significant during all sampling days, except for that in the spring. It was also different hourly on sampling days.


2012 ◽  
Vol 524-527 ◽  
pp. 2139-2142
Author(s):  
Shu Li Wang ◽  
Chao Ma ◽  
Wei Bin Yuan

The soil physical and chemical properties of four densities (A:2500/hm2,B:3300/hm2,C:4400/hm2,D:6600/hm2) of hybrid Larch plantations, Larix olgensis plantation(E) and Quercus mandsurica forest(F) were studied in Jiangshanjiao forest farm of Heilongjiang province of China. Soil bulk density, soil porosity, total N, total P, available N and available P were affected significantly by plantation density in hybrid Larch plantations. The lowest surface soil bulk density was in density 2500/hm2. Soil porosity of density 2500/hm2and 3300/hm2was bigger than that of density 4400/hm2and density 6600/hm2. Total N, total P and available N of density 4400/hm2and 3300/hm2were higher than that of density 6600/hm2and density 2500/hm2. Total N, total P, available N and available P of hybrid Larch plantations were not lower than that of Larix olgensis plantation. The results of the soil physical and chemical properties under different densities of hybrid Larch plantations and different types of forest seems to confirm that hybrid Larch plantation did not decreased the soil fertility, and the hybrid Larch plantation with densities of 3300/hm2and 4400/hm2could be conductive to improving the soil quality. The results would provide the theories basis for manage the hybrid Larch plantations.


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