Evaluation of the functionality of a constructed wetland system under semidesert and saline conditions

Abstract

Objective: Evaluate the functionality of a constructed wetland used to treat the wastewater from a school by recording water inflow and outflow, in addition to the local conditions that affect its operation and compliance with environmentalregulations.Design/methodology/approach: Verification of the installation specifications; programmed measurements of the inflowoutflowwater balance and ambient temperature; and analysis of the salinity effect and wetland performance.Results: The high evapotranspiration at the site contributed to the decrease in the resident volume of water within the wetland, causing water stress to the vegetation, not complying with the regulation about the reduction/elimination of water pollutants.Study limitations/implications: The high daytime temperature significantly decreased the daily inflow volume of wastewater, even after adding the precipitation water, which affects the biological activity of the vegetation; therefore, the study was performed on half of the wetland surface. Thus, the wetland was unable to reduce the pollutants to safe levels.Findings/conclusions: The amount of recovered treated water is minimal. The inflow is five times lower than the designed flow of the construction. The weekly log was appropriate to observe fluctuations in the water balance and its effect on the vegetation within the wetland.

Removal of Pathogenic Bacteria in a Horizontally Fed Subsurface Constructed Wetland Hybrid System

“…The concentration of fecal coliforms is negatively affected by solar radiation in shallow ponds and positively influenced by the tributary in deep ponds; in addition, the concentration of these bacteria is negatively affected by the ph in almost all of the system analyzed [44]. The high evapotranspiration at the installation site of the wetland contributed to generate water stress in the vegetation that is part of the system and influences the capacity of reduction and elimination of pollutants from the treated water [45]. Likewise, the sensitivity of pathogenic microorganisms to ultraviolet radiation has been highlighted, so that when entering the system part of them die and another fraction of these enter the system being found in the residual water in solid fraction or suspended [43,46,47].…”