Treatments of oil-refinery and steel-mill wastewaters by mesocosm constructed wetland systems

2005 ◽  
Vol 51 (9) ◽  
pp. 157-164 ◽  
Author(s):  
L. Yang ◽  
C.C. Hu
Keyword(s):  
Constructed Wetland ◽  
Wastewater Treatment Plants ◽  
Free Water ◽  
Oil Refinery ◽  
Oil Refining ◽  
Steel Mill ◽  
Total N ◽  
Boiler Water ◽  
Wetland System ◽  
Better Than

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.

Municipal wastewater treatment with pond–constructed wetland system: a case study

2005 ◽  
Vol 51 (12) ◽  
pp. 325-329 ◽  
Author(s):  
X. Wang ◽  
X. Bai ◽  
J. Qiu ◽  
B. Wang
Keyword(s):  
Constructed Wetland ◽  
Municipal Wastewater ◽  
Municipal Wastewater Treatment ◽  
Oxidation Pond ◽  
System A ◽  
Treated Effluent ◽  
Wetland System ◽  
Oxidation Ponds ◽  
Better Than

The performance of a pond–constructed wetland system in the treatment of municipal wastewater in Kiaochow city was studied; and comparison with oxidation ponds system was conducted. In the post-constructed wetland, the removal of COD, TN and TP is 24%, 58.5% and 24.8% respectively. The treated effluent from the constructed wetland can meet the Chinese National Agricultural and Irrigation Standard. The comparison between pond–constructed wetland system and oxidation pond system shows that total nitrogen removal in a constructed wetland is better than that in an oxidation pond and the TP removal is inferior. A possible reason is the low dissolved oxygen concentration in the wetland. Constructed wetlands can restrain the growth of algae effectively, and can produce obvious ecological and economical benefits.

Floral Colonization of a Free-Water Surface Constructed Wetland System in Grady County, Georgia

Castanea ◽  
2012 ◽  
Vol 77 (2) ◽  
pp. 159-171 ◽  
Author(s):  
Sarah A. White ◽  
Milton D. Taylor ◽  
Dixie Z. Damrel
Keyword(s):  
Constructed Wetland ◽  
Water Surface ◽  
Free Water ◽  
Free Water Surface ◽  
Wetland System

scholarly journals Hydrological tracers for assessing transport and dissipation processes of pesticides in a model constructed wetland system

2019 ◽  
Author(s):  
Elena Fernández-Pascual ◽  
Marcus Bork ◽  
Birte Hensen ◽  
Jens Lange
Keyword(s):  
Constructed Wetland ◽  
Preferential Flow ◽  
Free Water ◽  
Vertical Resolution ◽  
Term Basis ◽  
High Vertical Resolution ◽  
Wetland System ◽  
Temporal And Spatial ◽  
Dissipation Processes

Abstract. Hydrological tracers have been recently used as a low-cost approach to study the fate and transport of pesticides in constructed wetlands. Yet, internal temporal and spatial mechanisms that dominate their transport and dissipation in such environments are still not fully understood. We have applied three tracers with different sorptive and reactive properties: bromide (Br), uranine (UR) and sulforhodamine B (SRB) to investigate dominant temporal and spatial transport and dissipation processes of three selected pesticides: boscalid, penconazole and metazachlor in a model constructed wetland system designed to perform high vertical-resolution sampling and monitoring on a long-term basis. The experimental observations revealed that two different preferential flow paths developed, one due to the constructional design of the inflow and the other one due to the influence of the free water at the surface along with the plants. Transport of solutes was driven by the injections and dominated for Br, UR and metazachlor. The final mass balance highlighted that the main dissipation pathways were sorption, transformation and plant uptake. Sorption was detected immediately after the injection of solutes, while transformation was enhanced by the presence of plants and the promotion of aerobic conditions. The detection of metazachlor transformation products confirmed the contribution of transformation to metazachlor dissipation, whereas boscalid and penconazole mainly experienced sorption processes. The use of hydrological tracers together with selected pesticides and coupled with high vertical-resolution sampling and monitoring proved to provide valuable information about transport vectors and dissipation processes of pesticides in a vegetated redox-dynamic environment on a long-term basis and detailed spatial scale.

scholarly journals Performance and Kinetics of a Pond-Constructed Wetland System Treating Beef Manure Pile and Exercise Yard Runoff in Eastern Ontario

Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 168
Author(s):  
Juliana Mejia-Franco ◽  
Chris Kinsley ◽  
Robert Delatolla
Keyword(s):  
Constructed Wetland ◽  
Oxygen Demand ◽  
Free Water ◽  
Cost Effective ◽  
Reaction Rate Constants ◽  
Sources Of Pollution ◽  
Beef Producers ◽  
Wetland System ◽  
Eastern Ontario ◽  
Event Based

Runoff from manure piles and permanent outdoor confinement areas are common sources of pollution from livestock operations, which must be properly managed in accordance with local environmental regulations. Seven months of performance data from a pond-free water surface constructed wetland system receiving cattle feedlot runoff in Eastern Ontario, Canada, were used to evaluate performance and quantify first-order reaction rate constants (k) for organic matter and nutrients. Kinetic values were shown to be strongly temperature dependent and to adequately represent average treatment over the operating season; however, k values varied significantly on shorter time scales due to the event-based nature of the treatment system. Plant (duckweed) uptake of soluble phosphorus and ammonia in the pond was shown to be a predominant mechanism of nutrient removal. The pond-wetland system was effective at reducing biological oxygen demand (BOD5) by 67%, total phosphorus (TP) by 45%, and total nitrogen (TN) by 64%, providing a cost-effective and appropriate solution for beef producers.

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
Keyword(s):  
Design Process ◽  
Constructed Wetland ◽  
Wastewater Treatment Plants ◽  
Oxidation Ditch ◽  
Batch Mode ◽  
Total N ◽  
Acorus Gramineus ◽  
The Media ◽  
Total P ◽  
Wetland Design

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.

Combined biochar vertical flow and free-water surface constructed wetland system for dormitory sewage treatment and reuse

2020 ◽  
Vol 713 ◽  
pp. 136404 ◽  
Author(s):  
X. Cuong Nguyen ◽  
T.C. Phuong Tran ◽  
V. Hoan Hoang ◽  
T. Phuong Nguyen ◽  
Soon Woong Chang ◽  
...  
Keyword(s):  
Constructed Wetland ◽  
Water Surface ◽  
Sewage Treatment ◽  
Free Water ◽  
Vertical Flow ◽  
Free Water Surface ◽  
Wetland System

Application of constructed wetlands to treat some toxic wastewaters under tropical conditions

1996 ◽  
Vol 34 (11) ◽  
pp. 165-171 ◽  
Author(s):  
C. Polprasert ◽  
N. P. Dan ◽  
N. Thayalakumaran
Keyword(s):  
Constructed Wetlands ◽  
Constructed Wetland ◽  
Free Water ◽  
Operating Conditions ◽  
Organic Loading ◽  
Metal Compounds ◽  
Loading Rates ◽  
Tropical Conditions ◽  
Wetland System ◽  
Stems And Leaves

This study evaluated the potential of a free water surface constructed wetland system in treating some toxic wastewaters (i.e. phenolic and heavy metals). In a temperature range of 22–30°C, the constructed wetland units, whose hydraulic retention times (HRT) were 5–7 days, could remove more than 99% of the input phenol when they were operated at or below the organic loading rates (OLR) and influent phenol concentrations of 270 kg COD/(ha.d) and 400 mg/l, respectively. The effluent dissolved oxygen (DO) levels were 4–7 mg/l at OLR of 40–140 kg COD/(ha.d), but these DO levels decreased to 0.2–0.3 mg/l when the OLR were increased to 165–270 kg COD/(ha.d). Under similar operating conditions, the constructed wetland units could remove more than 99% of the applied chromium (Cr) and nickel (Ni), when either the Cr or Ni influent concentrations were 1–50 mg/l. The phenolic and heavy metal compounds were found to accumulate mostly at the roots of Typha, followed by the stems and leaves.

Sign in / Sign up

Export Citation Format

Share Document