Reclamation of agro-wastewater polluted with pesticide residues using sunlight activated persulfate for agricultural reuse.
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 SO4- 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 (900 L) were in the range 0.02-1.17 mg L-1 for acrinathrin and fluopyram, respectively. After treatment, nearly complete degradation (>97%) of the parent molecules was achieved although 13% of initial DOC was measured. No significant differences (p < 0.05) were found when comparing grown broccoli using reclaimed and unreclaimed water.
['Vela|Nuria|N|', 'Fenoll|José|J|', 'Garrido|Isabel|I|', 'Pérez-Lucas|Gabriel|G|', 'Flores|Pilar|P|', 'Hellín|Pilar|P|', 'Navarro|Simón|S|']
D000383:Agriculture D010573:Pesticide Residues D017670:Sodium Compounds D013431:Sulfates D013472:Sunlight D014865:Waste Disposal, Fluid D062065:Waste Water D014874:Water Pollutants, Chemical
Pesticides Persulfate Broccoli irrigation Solar photocatalysis Water reuse