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International Conference on

Recent Trends in Environmental Sustainability

ESCON22/SAgri/02
Integrated constructed wetland as a sustainable treatment method for domestic
wastewater

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Faria Javed , Sumbal Fazakat , Imran Hashmi 1*
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1 Institute of Environmental Sciences and Engineering (IESE), School of Civil and
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Environmental Engineering (SCEE), National University of Sciences and Technology
(NUST) H-12 Islamabad, Pakistan
Correspondence: imranhashmi@iese.nust.edu.pk

Abstract
Constructed wetlands (CWs) have long been recognized as effective wastewater treatment and
water resource reuse methods. The current study aimed to monitor the performance of a multi-
stage integrated constructed wetland located at NUST, Islamabad, Pakistan. This treatment
system consists of an inlet, sedimentation tank, eight ponds of horizontal subsurface flow
constructed wetland (HSSF-CW), and FILTER technology (filtration and irrigated cropping
for land treatment and effluent reuse). The constructed wetland contained specific hydrophytes
such as Typha latifolia, Pistia stratiotes and Centella asiatica. Different physicochemical and
microbial parameters for wastewater were analyzed according to American Public Health
Association (APHA) standard methods. For physicochemical analysis four points were
selected for sample collection i.e. inlet, sedimentation tank, pond 8 and collection tank.
Whereas samples for microbial analysis were collected from inlet and outlet (i.e. collection
tank). Concentration of gram-negative bacteria were determined using spread plate technique
on MacConkey Agar. Physicochemical parameters include temperature, pH, electrical
conductivity (EC), turbidity, total suspended solids (TSS), total dissolved solids (TDS), total
solids (TS), chemical oxygen demand (COD), dissolved oxygen (DO), nitrate-nitrogen (NO³¯-
N), nitrite-nitrogen (NO²¯-N), t total Kjeldahl nitrogen (TKN), and phosphate-phosphorous
(PO₄³⁻). The results showed that the average temperature, pH, and DO range between 23.95-
24.20, 6.95-7.20, and 2.25-3.10, respectively. Whereas other parameters showed the removal
efficiency as follow EC 10%, Turbidity 73.99%, TSS 79.70%, TDS 32.24%, TS 46.81%, COD
67.71%, NO³¯-N 53.94%, NO²¯-N 51.51%, TKN 63.01%, and PO₄³⁻ 41.44%. Whereas
removal rate of gram-negative bacteria was up to 95% with E. coli, Salmonella and Shigella as
dominant microbial species. Overall, this research indicates that an integrated constructed
wetland may significantly improve the water quality and is thus an efficient wastewater
treatment solution.
Keywords; Integrated constructed wetland; Domestic wastewater; Wastewater treatment;
Physicochemical parameters; Microbial parameter

Department of Environmental Sciences, COMSATS University Islamabad, Vehari Campus

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