Reducción de la carga orgánica de aguas residuales tóxicas de los laboratorios de la unas mediante oxidación avanzada Foto – Fenton

Abstract

The reduction of the organic matter content in toxic waste water from the seven laboratories at the Universidad Nacional Agraria de la Selva (General Chemistry and Inorganic, Phytochemistry, Soil Analysis, Biochemistry, Microscopy and Animal Health) through the solar photo-Fenton process was researched.  To optimize the process, the response surface methods were used, studying the dosing factors of H₂O₂ and Fe (II) on the variable, percentage of removal response of DQO (acronym in Spanish).  Before treatment, the waste water was characterized (DQO 10551 mgO₂/L, DBO₅ 850 mgO₂/L, total phenols 1740mg/L, nitrates 83250 mg/L, sulfates 104402 mg/L and pH 2.8); having concentrations which greatly surpassed the maximum allowable values. The concentration of Fe (II) was the significant variable for the removal of the DQO. With the optimization of the process, it was possible to remove a 95.3% of the DQO, 67.88% of the DBO₅ (acronym in Spanish), 100% of the total phenols, 91.12% of the nitrates and 90.4% of the sulfates was achieved, reducing the concentration of the parameters to values of: 495 mgO₂/L, 273 mgO₂/L, 0.002mg/L, 7312 mg/L and 10031 mg/L, respectively, which come in under the maximum allowable values.

An increase in the biodegradable index (DBO₅/DQO) was achieved, having started with 0.08 difficult biodegradable organic matter content, reaching an optimal 0.57 partially biodegradable organic matter content.  With which, it is proven that the treated waste water is less toxic than the initial waste water.