RECYCLING OF AGROINDUSTRIAL RESIDUAL WATERS FOR AGRICULTURAL PURPOSES (DRAINING OF THE BASIN OF THE ACONCAGUA RIVER) FOR THE RECOVERY OF DEGRADED SOILS: EVALUATION OF ANAEROBIC TECHNOLOGY

摘要

Water use optimization and the feasibility of recycling it becomes one of the most important challenges of the future, being specially relevant in fast growing zones that in the short term have continuous drought periods as it happens specifically in the case of the Aconcagua river basin (Chile). Also, the fast development of the zones plus the effect of contaminated water and soil residues have provoked a degradation of agriculture soils. We pose that agroindustry wastewaters treated with an anaerobic system has the proper characteristics for being used in irrigation of agricultural crops of high economical value and that all the anaerobic sludge generated by the treatment can be used to improve the soils. On the first stage, nursery plants (lemons) were daily irrigated, according Class A pan evaporation, with different water quality types (normal, treated residual water, non-treated residual water) and with different proportions of mixed normal and wastewater. Variables have been evaluated in order to calculate the hydric balance for each treatment with the purpose of evaluating the effects of irrigation regime and water quality over the plant water consumption. A chemical evaluation of each type of water was performed. A preliminary analysis of the observations performed within the period suggests that there is an effect of the irrigation levels on the diameter and height of the plants. This can be related to the contribution in micronutrients of each irrigation level. There is a tendency to an increment of such plant variables along with the increment of the concentration of wastewater applied.