[en] Saving natural resources as water is highly demanded all over the world. In agricultural systems is specially necessary to develop new technologies for water reuse and reclamation. The use of livestock wastewater is increasing over the years as supply the scarcity of irrigation water in agricultural lands. Constructed wetlands (CWs) are considered effective for the management and reclamation of livestock wastewater and others wastewater such as domestic, municipal sewage, storm water runoff, landfill leachate, or industrial wastewater before their reuse or discharge. Pig slurry (PS) has been frequently used as an organic fertilizer in direct application to soil, sometimes uncontrolled with the subsequent environmental risk of pollution. A low investment such as CW can increase the quality of this wastewater being a source of water and nutrients for agricultural purposes avoiding environmental risks. The objective of this study was to evaluate the efficiency of CW for treating PS for reuse as agricultural irrigation. This study was carried out in Lorca, Murcia Region. SE Spain. The integrated purification system was composed by a pretreatment that includes a storing tank, phases separator, shaking tank and sedimentation tank, also a horizontal subsurface flow constructed wetlands and a storage pond as secondary treatment. This system worked with an intermittent flow mode and a hydraulic retention time of 3 days. The samples were collected by triplicate at the outlet of each module of the system and physicochemical and microbial parameters were analyzed to calculate the efficiency of the whole system. The results showed a removal efficiency for STS (95 %), DQO (81%), DBO5 (78%), EC (16%), KN (62%), N-NH4 (53%), P (98%). Microbial parameters were removed in 100 % for most of them, such as total coliforms, fecal coliforms, E. coli, Salmonella and Shigella. Therefore, according to obtained results, treated pig slurry has better physic-chemical and microbial characteristics to be applied in agricultural soils. In addition, this study shows the possibility to save irrigation water using a low cost technology as CW reclaiming PS and minimizing environmental pollution.

[en] The wastewater generated by industrial activity contains a huge amount of contaminants, if this wastewater is not treated and managed properly, several environmental damages can be caused. In this study, constructed wetlands were used to treat wastewater from tannery industry in order to valorize and reuse it without any damages on the environment. This technology is environmental friendly, has low costs of implantation and management, and it has been used successfully in wastewater treatment, achieving notable decreases in the concentration of the main potential contaminants. This research aim to decrease contaminants concentration in tannery wastewater using a horizontal subsurface flow constructed wetland (HSFCW) as ecofriendly system. This study was carried out in Lorca, Murcia Region, Spain. The constructed wetland was worked in series, and it was composed by three cells filled with coarse gravel in the bottom (80 cm) and washed sand in the top (20 cm), and planted with Phragmites australis as phytoextractor species. The hydraulic retention times (HRT) in the wetland were 3 and 9 days. Three cycles were performanced for each HRT and the samples were collected in triplicate. Chromium (Cr), boron (B), Kjeldahl Nitrogen (KN) and phosphorus (P) concentrations were analyzed and the removal efficiencies were calculated. The contaminants levels were reduced for both HRTs, being 3 days the most effective retention time with a removal efficiency of 83% for chromium rather than HRT = 9 days with a removal efficiency of 60% for this element. In addition, the best results of B, KN and P removal were obtained with a HRT of 3 days being the efficiency of 41, 90 and 75%, respectively. Nevertheless, HRT = 9 showed a removal percentage of 33, 87 and 67 for B, KN and P, respectively. Therefore, the results of this study showed that horizontal subsurface flow constructed wetlands are a sustainable system for treating tannery wastewater. However the chemical/physical processes into the HSFCF should be evaluated in detail in order to understand the removal mechanisms of these elements.