Evaluation of wastewater post-treatment options for reuse purposes in the agricultural sector under rural development conditions

Abstract

Reuse of wastewater is a sustainable and renewable source of water, mainly used in the agricultural sector and can contribute to rural development. Agriculture is the second highest sector for water consumption in the Gaza Strip, using more than 50% of water abstractions from the stressed polluted Gaza's coastal aquifer. This paper aims to present and evaluate two available wastewater post-treatment options which could be employed to reuse wastewater for agriculture in Gaza: sand filtration using a textured geo-membrane sand filter and the Soil Aquifer Treatment (SAT) system. This evaluation is based on applying hierarchy grey relational analysis and the comparison matrix through an environmental assessment for each option using a semi-empirical methodology that combines results from field tests and computer hydrological simulations. In addition, it is based on a social and economic and the operational aspects for the Gaza City Wastewater Treatment Plant (WWTP) and its infiltration basin. The evaluation factors for the two options are juxtaposed in a Comparison Matrix with associated weighted scores and pre-defined scales to quantify the evaluation process before using the hierarchy grey relational analysis. The results show that the operational costs and the environmental aspects are the main factors that affect the evaluation process for wastewater post-treatment options. The sand filtration (with textured geo-membrane) option is ranked higher than the SAT system for this particular case study with an overall integrated grey relational grade equal to 0.3276, compared to 0.2596 for the SAT system.