Performance Assessment of Horizontal Subsurface Constructed wetland for the treatment of Winery wastewater
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Date
2019-06
Authors
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Publisher
Addis Ababa University
Abstract
Wastewater from human dwellings and activities has been a primary target of many
treatment technologies, including constructed wetlands. Constructed wetland technologies
for wastewater treatment is characterized by specific conditions enabling simultaneous
various physical and biochemical processes that are responsible for the removal and retention
of pollutants. Thanks to its advantages such as simple construction, easy operation and cost
effective maintenance, there is growing interest in the use of this technology for the
treatment of wastewater from different sources including industries.
The specific characteristic of industrial wastewater (new pollutants, extreme concentration,
low biodegradability, high toxicity) is a challenge for the application of constructed wetlands,
and therefore research is necessary to assess their viability and optimize their design and
operation. This study was undertaken to establish the efficacy of horizontal subsurface
constructed wetlands in purifying winery wastewater, and to examine the effect of water
depth and vegetation on the treatment efficiency.
The study used four pilot scale cells with water depth of 40 cm and 80 cm that were operated
at the same hydraulic residence time of ten days. Two cells were planted with local
macrophyte (bossarus aethopium) and the other two were left unplanted to be used as
control. The constructed wetlands exhibited good removal efficiency with respect to all the
major pollutants monitored i.e. COD, BOD, TSS, TDS, TKN, NH4
+
. The data
analysis indicated that the shallow wetland cells with a water depth of 40 cm had significantly
higher performance for the removal of COD, BOD, TKN and NH4
+
-
3-
, NO3
, TP and PO4
than the 80 cm deep cells.
Also, the planted wetland cells showed better removal efficiency for the organic matter and
nutrient than the unplanted cells.
The findings of this study showed positive results towards the use of HSSFCWs for the
treatment of winery wastewater. The 40cm deep planted cell had better overall performance
compared to the other cells and hence was used to design a large scale constructed wetland
for Awash winery. STELLA modeling tool was used to simulate the hydrologic dynamics of the
large scale constructed wetland.
Description
Keywords
Winery wastewater, Horizontal Subsurface Constructed wetland