Ascorbic acid/Fe@Fe2O3: A highly efficient combined Fenton reagent to remove organic contaminants

Abstract

In this study, we demonstrate that the combination of ascorbic acid and Fe@Fe2O3 core-shell nanowires (AA/Fe@Fe2O3) offers a highly efficient Fenton reagent. This combined Fenton reagent exhibited extremely high activity on the decomposition of H2O2 to produce OH for the degradation of various organic contaminants, including rhodamine B, methylene blue, alachlor, atrazine, siduron, lincomycin, and chloroamphenicol. The contaminant degradation constants in the AA/Fe@Fe2O3/H2O2 Fenton systems were 38-53 times higher than those in the conventional homogeneous Fenton system (Fe(II)/H2O2) at pH 3.8. Moreover, the OH generation rate constant in the AA/Fe@Fe2O3/H2O2 Fenton system was 1-3 orders of magnitudes greater than those of heterogeneous Fenton systems developed with other iron-containing materials (α-FeOOH, α-Fe2O3, FeOCl, and so on). The high activity of AA/Fe@Fe2O3 was attributed to the effective Fe(III)/Fe(II) cycle and the iron-ascorbate complex formation to stabilize ferrous ions with desirable and steady concentrations. During the AA/Fe@Fe2O3/H2O2 Fenton process, ascorbic acid served as a reducing and complexing reagent, enabling the reuse of Fe@Fe2O3 nanowires. We systematically investigated the alachlor and ascorbic acid degradation and found that they could be effectively degraded in the AA/Fe@Fe2O3/H2O2 system, accompanying with 100% of dechlorination and 92% of denitrification. This study sheds light on the importance of Fe(III)/Fe(II) cycle for the design of high efficient Fenton system and provides an alternative pathway for the organic contaminants removal.

Management of wilt disease of chickpea in vivo by silver nanoparticles biosynthesized by rhizospheric microflora of chickpea (Cicer arietinum)

“…Green synthesis of nanoparticles has received attention due to its use of environment-friendly precursors for nanoparticles synthesis with many other advantages such as economic viability, ease of production, eco-friendly nature, avoiding the use of harmful chemicals, conditions of high temperature and pressure, and the expensive instruments required for physical and chemical methods. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] Microorganisms have the ability to reduce heavy metal salts to metal nanoparticles with a narrow size distribution due to the presence of various reductase enzymes. 15 In a previous report, silver nanoparticles and PbS quantum dots were synthesized by Aspergillus sp.…”

Disordered Atomic Packing Structure of Metallic Glass: Toward Ultrafast Hydroxyl Radicals Production Rate and Strong Electron Transfer Ability in Catalytic Performance

“…In order to further understand the effect of the aforementioned structural features on the catalytic performance, the generation rates of •OH activated by the as‐received and annealed ribbons are investigated using benzoic acid (BA) as a probe . As shown in Figure a and Table 1 , the production rate constant of •OH using the as‐received ribbon is as high as 4.5 × 10 −2 s −1 , which is very close to our previous report (5.7 × 10 −2 s −1 ) .…”

“…Calculation of Reactive Radicals : For quantitative analysis of •OH, BA was used as the probe to calculate the production rate of •OH by the following Equations –. V 2 O 5 dissolved with H 2 SO 4 was employed for measuring the H 2 O 2 consumption where k probe is the first kinetic constant ( S −1 ) and also can be described as the second‐order kinetic rate for V •OH , presenting in Equation , S i presents •OH sink i in solution.…”

Treatment of persistent organic pollutants in wastewater using hydrodynamic cavitation in synergy with advanced oxidation process

“…The degradation of the AMX was however very slow resulting in the formation of unknown intermediate products. A single AOP system can accomplish partial degradation of recalcitrant organic pollutants, but rarely achieves complete mineralisation except in combination with other forms of AOPs or treatment procedures (Cai et al 2015;Hou et al 2016;Zhang et al 2013). Other challenges are the formation of unknown secondary by-products, costly chemical reagents (peroxide) and high energy requirement (UV and ultrasound).…”

“…Unfortunately, Fe 2+ /Fe 3+ rate of reaction in AFP is very low, causing a slow rate of reaction in the entire process (Wu et al 2013). Developing efficient, reusable and durable heterogeneous Fenton catalysts that are active over a wide pH range is the subject of ongoing research (Araujo et al 2011;Hou et al 2016). The application of zero valent iron nanoparticle (nZVI) as a heterogeneous catalyst in an AFP has recently been reported.…”