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The photolytic reduction of amorphous iron hydroxide [am-Fe(OH)3], lepidocrocite ( -FeOOH), goethite (a-FeOOH), hematite (ct-FeaOsband natural iron-containing aerosol particles in the presence of formaldehyde, formate, acetate, oxalate, and butyrate has been investigated. Important parameters in the photoreduction experiments are the pH, wavelength of the irradiating light, nature of the electron donor, characteristics of the iron phase. The present results show that the fastest rates of photoreduction of Fe(III) to Fe(II) are achieved with am-Fe(OH)3 as the electron acceptor and formate as the electron donor.Maximum rates of photoreduction were observed at 330 nm with a continuous decrease to 405 nm. Natural ironcontaining aerosol particles show photochemical behavior similar to am-Fe(OH>3 and -FeOOH. These results suggest that a significant fraction of the reactive atmospheric iron in urban aerosol could be present as am-Fe-(OH)s and -FeOOH. Ambient iron-containing aerosol particles with oxalate as the electron donor resulted in a significant photochemical production of H2O2.

An environmentally benign approach to impart stainless steel (SS) surfaces with antifouling and antibacterial functionalities was described. Surface-initiated atom transfer radical polymerization (ATRP) of poly(ethylene glycol) monomethacrylate) (PEGMA) from the SS surface-coupled catecholic L-3,4-dihydroxyphenylalanine (DOPA) with terminal alkyl halide initiator was first carried out, followed by the immobilization of lysozyme at the chain ends of poly(ethylene glycol) branches of the grafted PEGMA polymer brushes. The functionalized SS surfaces were shown to be effective in preventing bovine serum albumin (BSA) adsorption and in reducing bacterial adhesion and biofilm formation. The surfaces also exhibited good bactericidal effects against Escherichia coli and Staphylococcus aureus. The concomitant incorporation of antifouling hydrophilic brushes and antibacterial enzymes or peptides onto metal surfaces via catecholic anchors should be readily adaptable to other metal substrates, and is potentially useful for biomedical and biomaterial applications.

Arsenic contamination has been found in the groundwater of several countries. Photocatalysis can rapidly oxidize arsenite (As(III)) to less labile and less toxic arsenate (As(V)), which then can be removed by adsorption onto photocatalyst surfaces. This study investigates the photocatalytic oxidation of As(III) to As(V) as a function of As(III) concentration, pH, catalyst loading, light intensity, dissolved oxygen concentration, type of TiO2 surfaces, and ferric ions to understand the kinetics and the mechanism of As(III) oxidation in the UV/TiO2 system. Photocatalytic oxidation of As(III) to As(V) takes place in minutes and follows zero-order kinetics. Benzoic acid (BA) was used as a hydroxyl radical (.OH) scavenger to provide evidence for the .OH as the main oxidant for oxidation of As(III). The .OH radical was independently generated by nitrate photolysis, and kinetics of As(III) oxidation by the .OH radical was determined. Formation of salicylic acid (SA) from the oxidation of BA by .OH also demonstrates the involvement of .OH in the mechanism of As(III) oxidation. The effect of Fe(III) on As(III) oxidation at different pH values with and without TiO2 under UV light was examined. The results suggest that .OH is the dominant oxidant for As(III) oxidation. Two commercially available TiO2 suspensions, Degussa P25 and Hombikat UV100, were tested for the removal of arsenic through oxidation of As(III) to As(V) followed by adsorption of As(V) onto TiO2 surfaces. Results showed that complete removal of arsenic below the World Health Organization drinking water limit of 10 microg/L could be achieved.

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Anodic CuO nanoneedle array films were synthesized and modified by fluorosilanization to create superhydrophobic surfaces for effective corrosion protection.

Peracids have gained interest in the water treatment over the last few decades. Peracetic acid (CH 3 CO 3 H) has already become an accepted alternative disinfectant in wastewater disinfection whereas performic acid (CHO 3 H) has been studied much less, although it is also already commercially available. Peracids have also been tested for drinking water disinfection, oxidation of aqueous (micro)pollutants, sludge treatment and ballast water treatment, to name just a few examples. The purpose of this review paper is to represent comprehensive up-to-date information about the water treatment applications, aqueous reaction mechanisms, and disinfection byproduct formation of peracids, namely performic, peracetic and perpropionic acids. and PFA have several of the qualities of an ideal disinfectant: toxicity to microorganisms, but not to higher forms of life; effectivity at ambient temperatures; stability and long shelf-life; low corrosivity; deodorizing ability; widespread availability and reasonable cost [12].PAA and PFA are colorless liquids with characteristic pungent odors. Both are thermodynamically unstable and can decompose spontaneously or explode when highly concentrated, heated, under mechanical stress or exposed to catalytic effects of impurities [1,13,14]. The recommended storage temperatures are below 30 and 20°C for PAA and PFA, respectively [6,14]. Longer carbon chain length increases stability, and thus PAA is more stable than PFA [1]. However, the O-O bond dissociation energy of PFA and PAA has been calculated to be similar: 48 kcal/mol [15]. Percarboxylic acids have typically pK a values 3-4 units higher than the parent carboxylic acids [1]. Nonetheless, PFA and PAA are corrosive [16]. ACCEPTED MANUSCRIPT ACCEPTED MANUSCRIPT 3Exposure to PAA and PFA causes irritation and possibly permanent damage to the skin (cutaneous emphysema), eyes and the respiratory system. In the skin contact, 0.2% is proposed as the no-observed-effect concentration (NOEC) for short and medium length exposure [17].When inhaled, airborne concentrations less than 0.16-0.17 ppm (0.50-0.52 mg/m 3 ) are considered to cause no irritation [17,18]. However, higher concentrations are harmful and a case study suggested that PAA could cause occupational asthma [19].The largest users of PAA on a global scale (estimated in 2013) are shown in Fig. 1. Similar numbers are not available for PFA, but it is probably used at significantly lower quantities.The largest user, the food industry, applies PAA as a disinfectant in fresh produce washing water, clean-in-place (CIP) processes, on food processing equipment, and in pasteurizers, to name just a few examples [21,22]. PFA is also a suitable disinfectant in low-temperature refrigerated food processing and storage rooms [23]. In healthcare, PAA is used for instance in Recently, methods to determine the residual PAA from wastewater were compared: the spectrophotometric method using DPD and catalase was recommended for 0.1-0.5 mg/L PAA concentrations and the cerimetric/iodometric titration...