Agricultural valorization of sludge from the Jerada sewage treatment plant

Abstract

The reinforcement of the infrastructure in Morocco is accompanied by the setting up of several wastewater treatment plants which produce on the one hand purified water, but on the other hand, large quantities of sludge, are considered waste. Our work focused first on the physicochemical and bacteriological characterization of the sludge from the Jerada wastewater treatment plant (WWTP), which showed that all the parameters analyzed are more significant than those of other sludge studied, whether Moroccan or foreign. The richness of the residual sludge of the Jerada WWTP in fertilizing elements encourages its use as a soil amendment, germination tests of lentils and watercress were carried out for different percentages of sludge, for lentils, these tests showed that the sludge can be considered as a fertilizer at a concentration of 25%. In comparison with the results of the germination of lentils by olive pomace, the germination rate of the seeds decreases when the concentration of olive pomace increases. Then, a trial of sludge valorization in bean culture was carried out in the laboratory in order to study the impact of sludge amendment on plant growth (Bean), the monitoring of the parameters: Stem size, number of leaves, and leaf area showed that the sowing of bean in different concentrations of sludge and soil leads to a positive effect on bean yield on the three parameters, for concentrations of 5% and 10% sludge.