Cost Analysis and Health Risk Assessment of Wastewater Reuse from Secondary and Tertiary Wastewater Treatment Plants

Sara Abdelmoula,Mohamed T Sorour,Samia A Abdelrahman Aly

doi:10.3390/su132313125

Sara Abdelmoula, Mohamed T Sorour + Show 1 more

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https://doi.org/10.3390/su132313125

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Journal: Sustainability	Publication Date: Nov 26, 2021
Citations: 3	License type: CC BY 4.0

Affiliation: Alexandria University

Abstract

Irrigation with reclaimed water is a widespread solution to coping with water scarcity, especially in the Middle East and North Africa (MENA) region. This paper presents a systematic evaluation approach of six treatment alternatives proposed for Alexandria WWTP in Egypt as an applied example. This approach evaluates the effluent quality and cubic meter price from the proposed treatment alternatives while managing the health risks associated with reclaimed water irrigation. Rotavirus, Salmonella, Giardia duodenalis, and Ascaris were studied as waterborne pathogens. A quantitative microbial risk assessment model was used for the estimation of annual infection risks. The exposure scenarios include farmers and vegetable consumers. Activated sludge provided the lowest costs; however, it gave the lowest efficiencies and highest health risks. On the other hand, the highest efficiency and lowest health risks were obtained by the membrane bioreactor. The resulting price of a cubic meter of treated wastewater, used in irrigation, ranged from 0.082 to 0.133 USD. Irrigation using tertiary-treated wastewater achieved the target infection risk for unrestricted irrigation without using advanced treatment facilities. The results of this study could give a comprehensive view of reusing wastewater to decision-makers to address both water and food poverty not only in Egypt but also in other countries in MENA with similar economic and agro-ecological conditions.

Highlights

One of the major constraints to the socioeconomic sustainability of human livelihoods is water scarcity, which is the disparity between the water supply and demand
Efficiencies, estimating the cubic meter cost of reclaimed water that can be used in irrigation and managing health risks to achieve the target annual infection risk
Based on the value of pathogen concentrations in wastewater in Egypt, it can be noticed that both Salmonella and Giardia duodenalis, compared with Rotavirus and Ascaris, seem to have limited significance when reclaimed water is utilized for irrigation

Summary

Introduction

One of the major constraints to the socioeconomic sustainability of human livelihoods is water scarcity, which is the disparity between the water supply and demand. The increase in water demand is due to urbanization, population growth, changing patterns of consumption, and supply-side limiting factors, such as water pollution [1]. Reusing treated wastewater has become a main low-cost and reliable alternative. It has been considered a sustainable unconventional water resource that will increase in the future due to the continuous population increase especially in urban areas [3]. Macronutrients (nitrogen, phosphorous, and potassium) and several micronutrients (iron, zinc, manganese, and copper) are found more in wastewater than in any synthetic fertilizer, and these components are needed for optimal plant growth [4,5]. As a result, reusing these components may enhance soil structure and physical characteristics and may reduce the chemical fertilizers’ requirements [6]

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