Browsing by Subject "Persulfate"

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    Reclamation of agro-wastewater polluted with pesticide residues using sunlight activated persulfate for agricultural reuse.
    (Elsevier, 2019-04-10) Vela, Nuria; Fenoll, José; Garrido, Isabel; Pérez-Lucas, Gabriel; Flores, Pilar; Hellín, Pilar; Navarro, Simón; Química Agrícola, Geología y Edafología
    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 sodiumpersulfate (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 (N97%) of the parent molecules was achieved although 13% of initial DOC was measured. No significant differences (p b 0.05) were found when comparing grown broccoli using reclaimed and unreclaimed water.