Abstract:The degradation effect, degradation mechanism, oxidation kinetics, and degradation products of Atrazine (ATZ) by Ultrasound/Peroxymonosulfate (US/PMS) in phosphate buffer (PB) under different conditions were studied. It turned out that the degradation rate of US/PMS to ATZ was 45.85% when the temperature of the reaction system, concentration of PMS, concentration of ATZ, ultrasonic intensity, and reaction time were 20 °C, 200 μmol/L, 1.25 μmol/L, 0.88 W/mL, and 60 min, respectively. Mechanism analysis showed t… Show more
“…The use of ultrasound radiation showed a high removal of organic carbon, although the results were shown to be lower than those of UV-A and UV-C radiation. These results are in agreement with the work of Lu et al [70], who observed a 71.4% atrazine degradation in the PMS/US system.…”
Section: Sr-aops Applied To a High Load Wwsupporting
The large production of wine and almonds leads to the generation of sub-products, such as winery wastewater (WW) and almond skin. WW is characterized by its high content of recalcitrant organic matter (biodegradability index < 0.30). Therefore, the aim of this work was to (1) apply the coagulation–flocculation–decantation (CFD) process with an organic coagulant based on almond skin extract (ASE), (2) treat the organic recalcitrant matter through sulfate radical advanced oxidation processes (SR-AOPs) and (3) evaluate the efficiency of combined CFD with UV-A, UV-C and ultrasound (US) reactors. The CFD process was applied with variation in the ASE concentration vs. pH, with results showing a chemical oxygen demand (COD) removal of 61.2% (0.5 g/L ASE, pH = 3.0). After CFD, the germination index (GI) of cucumber and corn seeds was ≥80%; thus, the sludge can be recycled as fertilizer. The SR-AOP initial conditions were achieved by the application of a Box–Behnken response surface methodology, which described the relationship between three independent variables (peroxymonosulfate (PMS) concentration, cobalt (Co2+) concentration and UV-A radiation intensity). Afterwards, the SR-AOPs were optimized by varying the pH, temperature, catalyst type and reagent addition manner. With the application of CFD as a pre-treatment followed by SR-AOP under optimal conditions (pH = 6.0, [PMS] = 5.88 mM, [Co2+] = 5 mM, T = 343 K, reaction time 240 min), the COD removal increased to 85.9, 82.6 and 80.2%, respectively, for UV-A, UV-C and US reactors. All treated wastewater met the Portuguese legislation for discharge in a municipal sewage network (COD ≤ 1000 mg O2/L). As a final remark, the combination of CFD with SR-AOPs is a sustainable, safe and clean strategy for WW treatment and subproduct valorization.
“…The use of ultrasound radiation showed a high removal of organic carbon, although the results were shown to be lower than those of UV-A and UV-C radiation. These results are in agreement with the work of Lu et al [70], who observed a 71.4% atrazine degradation in the PMS/US system.…”
Section: Sr-aops Applied To a High Load Wwsupporting
The large production of wine and almonds leads to the generation of sub-products, such as winery wastewater (WW) and almond skin. WW is characterized by its high content of recalcitrant organic matter (biodegradability index < 0.30). Therefore, the aim of this work was to (1) apply the coagulation–flocculation–decantation (CFD) process with an organic coagulant based on almond skin extract (ASE), (2) treat the organic recalcitrant matter through sulfate radical advanced oxidation processes (SR-AOPs) and (3) evaluate the efficiency of combined CFD with UV-A, UV-C and ultrasound (US) reactors. The CFD process was applied with variation in the ASE concentration vs. pH, with results showing a chemical oxygen demand (COD) removal of 61.2% (0.5 g/L ASE, pH = 3.0). After CFD, the germination index (GI) of cucumber and corn seeds was ≥80%; thus, the sludge can be recycled as fertilizer. The SR-AOP initial conditions were achieved by the application of a Box–Behnken response surface methodology, which described the relationship between three independent variables (peroxymonosulfate (PMS) concentration, cobalt (Co2+) concentration and UV-A radiation intensity). Afterwards, the SR-AOPs were optimized by varying the pH, temperature, catalyst type and reagent addition manner. With the application of CFD as a pre-treatment followed by SR-AOP under optimal conditions (pH = 6.0, [PMS] = 5.88 mM, [Co2+] = 5 mM, T = 343 K, reaction time 240 min), the COD removal increased to 85.9, 82.6 and 80.2%, respectively, for UV-A, UV-C and US reactors. All treated wastewater met the Portuguese legislation for discharge in a municipal sewage network (COD ≤ 1000 mg O2/L). As a final remark, the combination of CFD with SR-AOPs is a sustainable, safe and clean strategy for WW treatment and subproduct valorization.
“…As can be seen from Figure 7B, when the concentration of ethanol reached 5 mM, the degradation percentage was 89.34%, indicating that SO 4 − · played a greater role than ·OH. The generation mechanisms of ·OH and SO 4 · − are consistent with Equations 3–5 53–55 …”
Section: Resultssupporting
confidence: 69%
“…The generation mechanisms of ÁOH and SO 4 Á À are consistent with Equations 3-5. [53][54][55] Fe III…”
Section: Effective Active Species Of the Catalytic Systemmentioning
The discharge of colored textile printing and dyeing wastewater causes environmental pollution. The fading of wastewater efficiently, simply and with low consumption is a problem to be considered. Herein, a catalytic method for rapid decolorization of organic dyes was devised employing terpyridine iron complex to activate oxidized permonosulfate (PMS). CI Acid Red 1 (AR1) was used as the simulated pollutant, the influences of operating parameters on the fading effects of wastewater were explored. According to the results, the produced catalytic system exhibits a universal catalytic effect. Even when the dye concentration reaches 76.4 mg/L, the dyeing wastewater may be effectively decolorized. In addition, when anions (HCO3−, SO42−, Cl−) were present in the solution, the degradation effect of AR1 was still effective. Interestingly, active species such as sulfate radicals and singlet oxygen were detected in the catalytic degradation system by radical capture experiments. The total organic carbon (TOC) can reach a removal rate of 26.22% at 2 h. This research provides a unique enzyme‐like catalytic system for the rapid breakdown of dye contaminants.This article is protected by copyright. All rights reserved.
“…However, comparing to the PMS dosage of 3 mM, the degradation rate of tetracycline decreased to 66.2% at the PMS dosage of 4 mM, which means that an appropriate increase in PMS dosage can promote the generation of more and •OH, and the tetracycline degradation. However, an excessive amount of PMS bursts and •OH, generating and •HO 2 with lower oxidizing capacity , and the reaction proceeds as follows [23] : As a result, there is an ideal PMS dosage for tetracycline degradation using DFUS/PMS. Fig.…”
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