Table 1 Existing literature on LCA and LCC of centralized and decentralized WWTPs.

This study

Bangkok, Thailand

2016–2017

✔

✔

AS

✔

✔

✔

The C-fertilizer scenario has the highest LCCA and is the most environmentally and economically viable treatment scenario because of the highest net cash flow

Hospido et al. ¹⁴

Galicia, Spain

2000–2001

✔

AS

✔

–

–

The main contributors to the environmental impacts were water discharge and sludge application to land. The AS achieved high nitrogen removal efficiency

Rodriguez-Garcia et al.¹⁵

Spain

2008

✔

AS, Extended aeration and Oxidation ditch

✔

✔

–

WWTPs with organic removal technology were less costly in environmental and economic terms. However, improvement in effluent worsened global warming impact and increased overall expense

Ontiveros and Campanella ¹⁶

Argentina

N.A. (simulation data)

✔

Conventional and biological nutrient removal processes

✔

–

–

The nutrient removal system significantly improved the quality of effluent and biosolids while reducing overall energy consumption

Li et al.¹⁷

Kunshan, China

2010

✔

Anaerobic-Anoxic–Oxic

✔

–

–

Eutrophication, global warming, and waterborne suspended particles were major contributing factors to the environmental impacts of Kunshan WWTP

Yoshida et al.¹⁸

Copenhagen, Denmark

2011

✔

Biological nitrogen removal

✔

–

–

Data collection should be standardized and expanded to include energy and chemical usage data, the elimination of a reporting threshold, the expansion of substance coverage, and the inclusion of non-point fugitive gas emissions

Lorenzo-Toja et al.¹³

Spain

2011

✔

✔

N.A

✔

–

–

The research examined 113 WWTPs with organic matter and nutrient removal technology in Spain using LCA. The results showed that large WWTPs were highly efficient

Lorenzo-Toja et al.¹²

Spain

2011

✔

✔

N.A

✔

✔

–

The research studied 22 WWTPs in Spain using LCA and LCC; and reported that the operation and maintenance costs of WWTPs with phosphorus and/or nitrogen removal were greater than those without nutrient removal

Limphitakphong et al.¹⁹

Bangkok, Thailand

2008

✔

Contact stabilization, AS with nutrient removal, Cyclic AS, Two-stage AS, and Vertical loop reactor AS

✔

✔

–

Vertical loop reactor AS achieved the highest pollutant removal efficiency. Electricity consumption was the main contributor of global warming potential and operation cost, while eutrophication as nutrient discharge was the major contributor of total impacts

Bertanza et al.¹¹

Brescia-Verziano, Italy

N.A

✔

Conventional AS and Membrane bioreactor

✔

✔

–

The advantages of conventional AS are ease of operation, minimal cost, and low energy consumption, while membrane bioreactor technology is commonly used with similar overall environmental footprint to AS

Garfí et al.²⁰

Catalonia and Barcelona, Spain

N.A

✔

AS, Hybrid constructed wetland and High rate algal pond

✔

✔

–

The AS process was costliest (in financial terms) among three treatment schemes under study. Meanwhile, wetland system required vast plots of land

Polruang et al.¹⁰

Bangkok, Thailand

2014

✔

Contact stabilization, AS with nutrient removal, AS, Two-stage AS, and Vertical loop reactor AS

✔

–

–

Electricity consumption was the main contributor to almost all environmental impacts. The reduction in fossil fuels use for electricity production reduced global warming, abiotic depletion, and acidification impacts

Arashiro et al.²¹

Barcelona, Spain

N.A

✔

AS and High rate algal pond

✔

✔

–

High rate algal pond system with biogas and biofertilizer production was more environmentally friendly than AS system. The high rate algal pond system was the sustainable and cost-effective technology for wastewater treatment in small communities

Singh et al.²²

India

2014–2015

✔

Moving bed biofilm reactor

✔

✔

–

Moving bed biofilm reactor achieved high organic removal efficiency but low nutrient removal efficiency

Awad et al.⁸

Gamasa, Egypt

2010

✔

Conventional AS

✔

✔

–

The operation phase generated greater environmental impacts than the construction phase. Air emissions and energy consumption were the main contributors of environmental impacts

Tabesh et al.⁹

Tehran, Iran

✔

Aeration lagoons

✔

–

–

Use of biogas contributed significantly to the environmental impacts. Use of treated wastewater as irrigating water on farmland mitigated the eutrophication effect