Removal of emerging contaminants from intensive animal farming waste water using magnetic activated carbon

MARÍA DEL ROSARIO MOREL; RINTOUL, IGNACIO; MURGUÍA, MARCELO CÉSAR

mONTEVIDEO

Simposio; 2ND PHD STUDENT SYMPOSIUM ON ?MATERIALS FOR ENERGY, ENVIRONMENT AND HEALTH? AUGM-BAYLAT; 2022

Association of Universities Grupo Montevideo (AUGM ) and Bavarian University Center for Latin America (BAYLAT)

Abstract: Livestock is an important source of emerging contaminants such as antibiotics, antiparasitics and hormones. Oxytetracycline (OTC) is a broad-spectrum antibiotic widely used to keep the sanitary conditions in intensive farms facilities. The removal of this compound from intensive farms waste-waters using a cheap and simple process is atechnological challenge.The goal ofthis contribution is the synthesis and characterization of Magnetic ActivatedCarbon (MAC) and the assessment of its effectiveness for removal OTC from intensive farms facilities waste-waters. Methodology: MAC wassynthesized using the following methods 1) adsorption of nanomagnetite ontoactivated carbon (AC), 2) oxidation in the presence of nitrates and 3)impregnation pyrolysis. Mossbaüer spectroscopy and X-ray diffraction were usedto identify the Fe species formed. The magnetic properties were measured usinga vibrating-sample magnetometer. The adsorption of OTC onto AC and MAC wasstudied trough the construction of the equilibrium isotherms. OTCconcentrations were followed through time to assess the sorption efficiency onAC and MAC. The effects of sorbent dose, pH, ionic strength and water hardnesson the adsorption process were studied using the Taguchi L-9 experimentaldesign. The sedimentation capacity of AC and MAC was determined by UV-Visspectrophotometry in transmittance mode (400-700 nm). Results: Freundlich model adjusted with R^2 >0.92 and >0.92for AC and MAC, respectively. Langmuir model adjusted with R^2 >0.93 and>0.89 for AC and MAC, respectively. For AC, removal of 70% of OTC wasachieved at t = 24h. For MAC, 70% removal was achieved at t = 8h, and 90%removal was achieved at t = 24h. The equation of response surface was: Cads=97,65 + 122,0 A - 11,92 B - 170,3 C + 0,006600 D - 1411 A2 + 0,8200B2 + 1774 C2 - 0,000011 D2, where A, B, C, andD are the adsorbent dose, the pH, the ionic strength and the water hardness,respectively. The Transmittance index for AC and MAC resulted 0.46 and 0.74,respectively. Future contributions will be directed to the design of a pilotdevice to test this method on real feedlot waste-waters.