Evaluation of constructed wetlands for phytoremediation of treated sewage effluent and biomass production under suboptimal temperature /
Jiang, Bai Yang,
Evaluation of constructed wetlands for phytoremediation of treated sewage effluent and biomass production under suboptimal temperature / Jiang Bai Yang - xv, 150 pages : illustrations (some color) ; 30 cm. + 1 CD-ROM
Faculty of Civil Engineering Technology
Thesis (Doctor of Philosophy in Civil Engineering) -- Universiti Malaysia Pahang Al Sultan Abdullah - 2025
Includes bibliographical references
Constructed wetlands (CWs) are widely recognized as sustainable solutions for advanced wastewater treatment, particularly in regions facing cold climates and stringent water quality standards. In China, despite the expansion of municipal wastewater treatment plants (WWTPs), effluents from secondary treatment often fail to meet surface water quality standards (GB 3838-2002), especially during winter when low temperatures reduce microbial activity and hinder treatment efficiency. This study addresses this problem by evaluating the effectiveness of horizontal subsurface flow CWs (HFCWs) planted with Phragmites australis, Scirpus validus, and Typha orientalis under simulated winter conditions. The main objectives were to assess pollutant removal (COD and TN), monitor greenhouse gas (GHG) emissions (CO₂, CH₄, N₂O), analyze heavy metal accumulation and translocation, and conduct a life cycle assessment (LCA) incorporating biomass utilization strategies. Experiments were conducted in controlled tanks using treated WWTP effluent, and water and gas samples were analyzed using standard national methods and gas chromatography. Heavy metals (Pb, Zn, Cr, Mn) were measured via ICP, and global warming potential (GWP) was calculated in CO₂ equivalents. Two biomass reuse scenarios: animal feed and anaerobic digestion, were compared for sustainability. Results showed that S. validus had the highest COD and TN removal (40.16% and 34.88%, respectively), and the lowest GWP (3.086±0.741 mg/m2/h), while T orientalis emitted more CO₂ and GWP (178.30±11.72 mg/m2/h and 6.632±0.691 mg/m2/h, respectively). Metal uptake varied among species, the BAQ for different plant parts follows the same order: Zn > Mn > Pb > Cr, the high BCF values (>1) observed indicate strong accumulation potential, with roots acting as primary sinks (TF<1), reducing translocation to aboveground parts. LCA revealed that construction had the highest environmental burden, while biofertilizer or organic fertilizer offered better overall sustainability benefits than animal feed uses in three categories: Human Health, Climate Change, and Resources. This study contributes new insights on CW performance under winter conditions, offering practical recommendations for integrating CWs into 吖 cold-region wastewater systems. The findings support national CW guidelines and promote lowemission, circular wastewater solutions.
THE0010430 (Local)
Faculty of Civil Engineering Technology--Dissertations
Universities and colleges--Dissertations
Theses--Dissertations
Evaluation of constructed wetlands for phytoremediation of treated sewage effluent and biomass production under suboptimal temperature / Jiang Bai Yang - xv, 150 pages : illustrations (some color) ; 30 cm. + 1 CD-ROM
Faculty of Civil Engineering Technology
Thesis (Doctor of Philosophy in Civil Engineering) -- Universiti Malaysia Pahang Al Sultan Abdullah - 2025
Includes bibliographical references
Constructed wetlands (CWs) are widely recognized as sustainable solutions for advanced wastewater treatment, particularly in regions facing cold climates and stringent water quality standards. In China, despite the expansion of municipal wastewater treatment plants (WWTPs), effluents from secondary treatment often fail to meet surface water quality standards (GB 3838-2002), especially during winter when low temperatures reduce microbial activity and hinder treatment efficiency. This study addresses this problem by evaluating the effectiveness of horizontal subsurface flow CWs (HFCWs) planted with Phragmites australis, Scirpus validus, and Typha orientalis under simulated winter conditions. The main objectives were to assess pollutant removal (COD and TN), monitor greenhouse gas (GHG) emissions (CO₂, CH₄, N₂O), analyze heavy metal accumulation and translocation, and conduct a life cycle assessment (LCA) incorporating biomass utilization strategies. Experiments were conducted in controlled tanks using treated WWTP effluent, and water and gas samples were analyzed using standard national methods and gas chromatography. Heavy metals (Pb, Zn, Cr, Mn) were measured via ICP, and global warming potential (GWP) was calculated in CO₂ equivalents. Two biomass reuse scenarios: animal feed and anaerobic digestion, were compared for sustainability. Results showed that S. validus had the highest COD and TN removal (40.16% and 34.88%, respectively), and the lowest GWP (3.086±0.741 mg/m2/h), while T orientalis emitted more CO₂ and GWP (178.30±11.72 mg/m2/h and 6.632±0.691 mg/m2/h, respectively). Metal uptake varied among species, the BAQ for different plant parts follows the same order: Zn > Mn > Pb > Cr, the high BCF values (>1) observed indicate strong accumulation potential, with roots acting as primary sinks (TF<1), reducing translocation to aboveground parts. LCA revealed that construction had the highest environmental burden, while biofertilizer or organic fertilizer offered better overall sustainability benefits than animal feed uses in three categories: Human Health, Climate Change, and Resources. This study contributes new insights on CW performance under winter conditions, offering practical recommendations for integrating CWs into 吖 cold-region wastewater systems. The findings support national CW guidelines and promote lowemission, circular wastewater solutions.
THE0010430 (Local)
Faculty of Civil Engineering Technology--Dissertations
Universities and colleges--Dissertations
Theses--Dissertations