Transgenerational impact of DEHP on body weight of Drosophila.

Bis(2-ethylhexyl) phthalate (DEHP) is the most typical plasticizer and an environmental endocrine disruptor (EDC). DEHP is known to influence offspring fertility, growth, and obesity. However, the role of the DEHP as a transgenerational obesogen is still controversial. In this study, we used fruit flies (Drosophila melanogaster) to investigate where the exposure period, doses, and exposed parental sex are critical to change the body weight of the offspring. We found long-term but not short-term, and high-dose but low-dose exposure resulted in significant change. Moreover, we found DEHP treatment on the father or mother Drosophila resulted in increased or decreased body weight of the offspring respectively. Our results demonstrated the heterogeneity of transgenerational impact of DEHP and highlighted the involvement of parental endocrine system in its role as an obesogen.

DEHP toxicity on vision, neuromuscular junction, and courtship behaviors of Drosophila.

Bis(2-ethylhexyl) phthalate (DEHP) is the most common plasticizer. Previous studies have shown DEHP treatment accelerates neurological degeneration, suggesting that DEHP may impact retinal sensitivity to light, neurotransmission, and copulation behaviors. Although its neurotoxicity and antifertility properties have been studied, whether DEHP exposure disrupts vision and how DEHP influences neuromuscular junction (NMJ) have not been reported yet. Moreover, the impact of DEHP on insect courtship behavior is still elusive. Fruit flies (Drosophila melanogaster) were treated with series concentrations of DEHP and observed for lifespan, motor function, electroretinogram (ERG), electrophysiology of neuromuscular junction (NMJ), courtship behaviors, and relevant gene expression. Our results confirmed the DEHP toxicity on lifespan and capacity of motor function and updated its effect on copulation behaviors. Additionally, we report for the first time that DEHP exposure may harm vision by affecting the synaptic signaling between the photoreceptor and the laminar neurons. Further, DEHP treatment altered both spontaneous and evoked neurotransmission properties. Noteworthy, the effect of DEHP exposure on the copulation behavior is sex-dependent, and we proposed potential mechanisms for future investigation.

The application of electrocoagulation for the conversion of MSWI fly ash into nonhazardous materials.

This research investigated the electrocoagulation of municipal solid waste incineration (MSWI) fly ash at a liquid-to-solid ratio (L/S) of 20:1. The leachate that was obtained from this treatment was recovered for reutilization. Two different anodic electrodes were investigated, and two unit runs were conducted. In Unit I, the optimum anode was chosen, and in Unit II, the optimum anode and the recovered leachate were used to replace deionized water for repeating the same electrocoagulation experiments. The results indicate that the aluminum (Al) anode performed better than the iridium oxide (IrO2) anode. The electrocoagulation technique includes washing with water, changing the composition of the fly ash, and stabilizing the heavy metals in the ash. Washing with water can remove the soluble salts from fly ash, and the fly ash can be converted into Friedel's salt (3CaO·Al2O3·CaCl2·10H2O) under an uniform electric field and the sacrificial release of Al(+3) ions, which stabilizes the toxic heavy metals and brings the composition of the fly ash to within the regulatory limits of the toxicity characteristic leaching procedure (TCLP). Use of the Al anode to manage the MSWI fly ash and the leachate obtained from the electrocoagulation treatment is therefore feasible.

Basic characteristics of leachate produced by various washing processes for MSWI ashes in Taiwan.

Approximately 19.2% of Taiwan's municipal solid waste (MSW) that passes through incineration disposal is converted into ashes (including bottom ash and fly ash). Although bottom ash can pass nearly all of the standards of the toxicity characteristic leaching procedure (TCLP), its high chloride content makes its reuse limited; it generally cannot be used as a fine aggregate material in concrete applications. This research examined washing four types of bottom ash (BA) and fly ash (FA) with water to reduce their chloride content. The optimal water intensity for washing pretreated bottom ash was found to be 7-8L of water per kg of bottom ash, and the optimal water intensity for washing untreated fly ash was found to be 20-25 L of water per kg of fly ash. Based on regression analyses of the chloride concentrations of the leachates and their electrical conductivity (EC) values, each MSW incineration plant has its own ash characteristics as well as a specific regression line in bottom or fly ash leachate. Clearly, it is possible to monitor the EC values of the leachates online by estimation from regression equations to determine the chloride concentrations in the leachates.