Sustainability evaluation for water and sludge management in small islands: the case study in Kinmen, Taiwan

Sustainability evaluation for water and sludge management in small islands: the case study in Kinmen, Taiwan

Huan-Yu Shiu, Mengshan Lee, Pei-Te Chiueh

National Taiwan University, Taiwan

Sustainable management of water resource and solid waste in small islands is a critical challenge. Therefore, this study intends to investigate best management practices to address the challenge from environmental impact perspectives. Several resource management strategies, including four water supply scenarios (baseline water supply, water importation, desalination of seawater, and reclamation of wastewater) and two waste management scenarios (sludge reuse for agricultural applications and reuse for electricity generation) were proposed for the Kinmen islands. Results from the life cycle assessment showed that water importation (7.94E-14 as normalized impact) had the lowest environmental impact, followed by reclamation of wastewater (9.68E-14 as normalized impact). In the results for sludge management, significant reductions in global warming potential (from 32.4 to -18.8 kg CO2 eq) and photochemical oxidation impact were observed, when the sludge was used as replacements for fertilizers. The energy generated from sludge incineration was about 67% greater than the energy requirement for the system, thus, significantly reduced its overall environmental impacts. This study could provide useful information for sustainable management practices in small islands.