The objective of present work was evaluating the influence Phragmites australis (common reed) and Lemna minor (duckweed) aquatic plants in the reduction of total hardness and chlorides present in the waters of wells of Huanchaquito- Trujillo. They are used by the inhabitants to irrigate crops and own consumption, affecting their health and having low production in their fields. The aquatic plants used for the treatment of well water, according to background, have a high yield in salt absorption which has allowed to decrease the amount of Chlorides and hardness present at the well’s waters of Huanchaquito every 15 days for 8 months. The data obtained in the analyses of the initial samples were: With respect to hardness 542,7 ppm; Cl- amount 300,7 ppm. After the average data obtained for the hardness were of 502,4 ppm with Lemna minor only 537,6ppm, with Phragmites australis only and 489,8 ppm with Lemna minor and Phragmites australis, In terms of the results of chlorides we have: 296,9 ppm with Lemna minor only, 248,8 ppm with Phragmites australis only and 233,8ppm with Lemna minor and Phragmites australis.

The present research evaluated treatment time, electrode area / effluent volume ratio, on the% reduction of hexavalent chromium in artificial chrome plating effluents, was evaluated by the batch electrocoagulation method; Method for which A-36 steel anodes and cathodes of (5.0 x 5.0 x 0.2) cm were used. The number of electrodes and the separation between them was varied in order to vary the ratio of electrode area / effluent volume and; for a batch type electrocoagulation reactor in which 27 tests were carried out; keeping the volume of effluent treated constant. From the results obtained, it was determined that the increase in the electrocoagulation time and the electrode area / effluent volume ratio influence the percentage of hexavalent chromium reduction of the artificial chromium plating, as supported by ANOVA and test F; the maximum reduction percentage achieved was 91.65%, with respect to the initial concentration (20 mg/L), for a test time of 60 minutes and a ratio of electrode area / effluent volume of 0.912 m2/L.

The present research evaluated the effect of the nitriding time in plasma in the range of 5 to 15 hours, on the hardness profile of the cross section of stainless steel samples AISI 431; in addition to taking and differentiating the data on surface hardness, effective layer depth and nitride layer thickness. The nitriding process was by plasma, the process temperature was kept constant at 400 °C. The evaluated samples were machined (rolled and countersigned), and were left in one inch diameter and one inch in length. The times of 10 and 15 hours of nitriding time were obtained by accumulating time of 05 hours of nitriding per week; the hardness profiles were obtained by using the LECO model LMV-50V micro durometer; The ASTM E3-91 standard was used to collect the aforementioned hardness data, from these it was possible to determine that the maximum surface hardnesses are (1053, 1252 and 1327) HV-0.01, for nitriding times of (5,10 and 15) hours respectively, the average effective layer thicknesses were (37.75, 33 and 28.75) μm; while the nitride layer thicknesses were (4.9, 7.03 and 10.7) μm corresponding to times of (5, 10 and 15) hours respectively. The hardness in the core after the nitriding treatment was kept in the range of (275-277) HV-0.01. These values were determined by microscopic evaluation of the tested samples, the metallography reagent used was 3% Nital by electrolytic attack for 3 minutes in each case. The statistical analysis corresponded to Student's “t” tests, in the form of pairwise comparison, from which the non-significant difference between repetitions and the significant difference between the different levels of study were determined.