Reclamation of agro-wastewater polluted with pesticide residues using sunlight activated persulfate for agricultural reuse
Fecha
2019-01-07Disciplina/s
Ciencias AmbientalesMateria/s
Broccoli irrigationPersulfate
Pesticides
Solar photocatalysis
Water reuse
Resumen
The removal of 17 pesticides (pymetrozine, flonicamid, imidacloprid, acetamiprid, cymoxanil, thiachloprid, spinosad, chlorantraniliprole, triadimenol, tebuconazole, fluopyram, difenoconazole, cyflufenamid, hexythiazox, spiromesifen, folpet and acrinathrin) found in agro-wastewater from washing of containers and phytosanitary treatments equipment, has been carried out using sodium persulfate (Na2S2O8) at pilot plant scale under natural sunlight. Persulfate is a strong oxidant, inexpensive and environmentally appropriate. However, this oxidant is slow in kinetics under ordinary conditions. Na2S2O8 can be activated by ultraviolet light, generating SO4radical dot− radicals, which are also a very strong oxidizing species (E0 = 2.6 V). Previously, preliminary experiments were carried out at laboratory scale using a photoreactor to optimize the Na2S2O8 (300 mg L−1) concentration on the rate constants of the found pesticides. The residual levels of the studied pesticides in agro-wastewater (90...