Efficient degradation and mineralization of diclofenac in water on ZnMe (Me: Al; Co; Ga) layered double hydroxides and derived mixed oxides as novel photocatalysts

The removal of diclofenac (DCF) from aqueous solutions was attempted using photocatalytic processes, involving a series of novel photocatalysts based on ZnMe (Me: Al; Co; Ga) layered double hydroxides (LDHs) and their derived mixed oxides. The catalysts were characterized using specific techniques. Under solar light, ZnCo and ZnGa catalysts degraded almost completely DCF from water, while the mineralization, expressed by total organic carbon removal, reached $\sim$85%. The degradation mechanisms of DCF photolysis and photocatalytic degradation under solar and UV irradiation were investigated

Occurrence of selected organic contaminants in edible insects and assessment of their chemical safety

BACKGROUND: Feeding the continuously growing world population is challenging, and edible insects offer a sustainable alternative to conventional sources of animal proteins. As with any food source, the potential presence of hazardous organic chemicals, such as persistent organic pollutants (POPs), plasticizers and flame retardants (FRs), must be investigated to guarantee consumer chemical safety. OBJECTIVES: Here, we have investigated the contamination levels of several classes of organic compounds in edible insects. To evaluate their chemical safety, a dietary exposure risk assessment was then performed by combining the measured chemical contamination with the most recent food consumption data from local surveys. METHODS: Insect samples, belonging to six orders (Orthoptera, Coleoptera, Lepidoptera, Hemiptera, Odonata, Hymenoptera) were purchased from five European and three Asian countries. POPs and halogenated FRs were analyzed by gas chromatography-mass spectrometry (GC/MS) and organophosphorus FRs and plasticizers were quantified by liquid chromatography-MS/MS, according to validated protocols. RESULTS: The overall levels of chemical contamination varied greatly among the insect orders and country of purchase, hut they were generally low and comparable with other commonly consumed animal products. DISCUSSION: Here we show that, besides the activities during rearing, the industrial post-harvesting handling and addition of ingredients are supplementary factors influencing the chemical load of the final insect food-product. The total estimated dietary intakes of the considered classes of compounds through insect consumption are comparable with those generally assessed in common food of animal origin worldwide and, when compared with existing reference dose values, suggest that the risk of adverse health effects from exposure to the targeted organic compounds via insect consumption is unlikely

Occurrence of organophosphorus flame retardants and plasticizers in wild insects from a former e-waste recycling site in the Guangdong province, South China

Due to the fast growth of the electronic industry, a large quantity of electronic waste (e-waste) is generated worldwide and then often inappropriately dismantled and disposed of. In a pilot study, the occurrence of organophosphorus flame retardants and plasticizers (PFRs) was investigated for the first time in several wild insect species collected from a former e-waste recycling site in the Guangdong province, South China. TEHP was the most abundant PFR (average concentration of 5.8 ng/g ww), followed by TPHP (2.5 ng/g ww), TCIPP (2.2 ng/g ww), TCEP (0.8 ng/gww), EHDPHP and TCP (both 0.1 ng/gww). Dragonfly nymphswere the most contaminated insects, with total PFR concentrations of 68 ng/gww, followed bymoth adults (26 ng/gww) and terrestrial stinkbug (17 ng/g ww). The different contamination patterns observed in the analyzed insects could be explained by their different habitats and feeding habits. This study shows that e-waste recycling areas can be an important local source of contamination with PFRs, mainly caused by inadequate recycling activities. (C) 2018 Elsevier B.V. All rights reserved