Valorisation des eaux de retour des serres agricoles chauffée par l’eau géothermique dans le sud tunisien

Abstract

The sector of protected crops under heated greenhouses in southern Tunisia has continued to develop with the availability of geothermal resources. The poor management of these resources leads to their degradation in terms of quantity and quality. This situation is worsening with the demand for water in the agricultural sector. Therefore, the development of these geothermal potentials is necessary to ensure their sustainability. The present work aims at characterizing the return water and assessing its impact on greenhouse crops and oasis systems. The study was based on physico-chemical analyses of return water collected from nine geothermal poles spread over the three governorates (Gabes, Kebili and Tozeur), field visits and surveys conducted with farmers. These physico-chemical analyses indicate a poor to average water quality with a very high saline risk and a medium alkaline risk. Indeed, the salinity of the water varies from 2.6 to 11.9 g/l and the SAR from 5.1 to 8.8. In addition, the salinity management techniques adopted by farmers are still limited due to their low financial capacity.

Evaluating the Effectiveness of Coagulation–Flocculation Treatment Using Aluminum Sulfate on a Polluted Surface Water Source: A Year-Long Study

“…Furthermore, it is worth highlighting that in conventional drinking water treatment facilities pH correction is typically performed at the end of the treatment process, just before distribution. It is also pertinent to mention that there is a documented decrease in the effectiveness of chlorine against microbial contamination beyond a pH value of 8.19 [47][48][49]. Nevertheless, the pH adjustments resulting from Al 2 (SO 4 ) 3 treatment in this study remained well within acceptable ranges, thereby ensuring that water quality met the relevant standards without compromising safety.…”