RESUMEN

To explore the pollution characteristics, potential sources, and ecological and health risk of organophosphate eaters (OPEs) in the surface water of Taihu Lake, water samples from 18 surrounding rivers were collected, as well as 11 water samples from Taihu Lake. The concentrations of 13 OPEs in the water were determined using UPLC-MS/MS, and the spatial distribution of the OPEs in surface water of Taihu Lake basin was further analyzed. The results indicate that, in addition to tripropyl phosphate (TPrP), 2-ethylhexyl diphenyl phosphate (EHDPP), and tricresyl phosphate (TCrP), ten OPEs were detected in all the water samples, the total concentration (ΣOPEs) ranged from 152.5 ng·L-1 to 2524 ng·L-1, and the concentration median value was 519.2 ng·L-1. Tri(chloropropyl) phosphate (TCPP) and tri(2-chloroethyl) phosphate (TCEP) were the dominant OPEs, with the concentration ranges of 73.7-1753.9 ng·L-1 (medium value:204.6 ng·L-1) and 43.9-313.5 ng·L-1 (medium value:131.3 ng·L-1), respectively. The ΣOPEs decreased from the northwest region to the southeast, which corresponds to the economic and industrial development. The results of the source identification reveal that the wastewater discharge from electronics and textile enterprises, construction materials, and vehicular and marine traffic emissions may be the principal sources of the OPEs in Taihu Lake. The ecological risk assessment results indicate that only TCPP, tri(dichloropropyl) phosphate (TDCP), and triphenyl phosphate (TPhP) in some sites had a low risk. The health risk assessment reveals that there were no risks based on water intake, but the long-term risk of OPEs to the aquatic ecosystem and surrounding residents still need attention.

Asunto(s)

Retardadores de Llama , Contaminantes Químicos del Agua , China , Cromatografía Liquida , Ecosistema , Monitoreo del Ambiente , Ésteres , Retardadores de Llama/análisis , Lagos , Organofosfatos , Medición de Riesgo , Ríos , Espectrometría de Masas en Tándem , Agua , Contaminantes Químicos del Agua/análisis

RESUMEN

Ephedrine (EPH) is an alkaloid commonly used to relieve nasal congestion caused by colds, allergic rhinitis, rhinitis, and sinusitis, and to control bronchial asthma. It is also be used as a raw material in the manufacture of methamphetamine. Although the distribution of EPH in surface waters has been widely studied, its uptake, internal distribution, and toxicokinetic processing in exposed organisms have not been well investigated. In this study, we investigated the uptake, disposition, and toxicokinetics of EPH in zebrafish (Danio rerio) in a semi-static exposure system. EPH was consistently detected in zebrafish biological samples, with the highest concentrations of 84.97 ng·g-1 detected in the brain tissue of fish in the high treatment group. Over the 14-d exposure period, the relative abundance of mean concentrations of EPH in biological samples generally followed the order of brain > ovary > liver > intestine > muscle. The uptake rate constants (Ku), elimination rate constants (Ke), and half-lives of EPH in the biological tissues were in the ranges 0.23-570.31 L·(kg·d)-1, 1.22-6.11 d-1, and 0.12-0.57 d, respectively. The observed bioconcentration factor (BCFo) and kinetically-derived bioconcentration factor (BCFk) were similar, ranging 0.24-337.33 L·kg-1 and 0.13-316.43 L·kg-1, respectively. These results are helpful for understanding the behavior of psychoactive substances in aquatic organisms and have directive significance for studying their toxicity and ecological risks to aquatic organisms.

Asunto(s)

Contaminantes Químicos del Agua , Pez Cebra , Animales , Organismos Acuáticos , Efedrina/toxicidad , Femenino , Toxicocinética , Contaminantes Químicos del Agua/toxicidad

RESUMEN

Designing low-cost and high-active bifunctional catalysts for overall water splitting has attracted increasing research interest. Herein, the brilliant overall water splitting performance of cobalt-vanadium bimetal-based nanocomposites is explored. Co-V based nanocomposites are synthesized through a one-step hydrothermal method, in which the cobalt species is introduced into the lepidocrocite VOOH and further cobalt vanadium oxide is formed. The additive level of cobalt is optimized and the corresponding effect on electrocatalytic activity is also investigated in this work, systematically. The targeted catalyst (denoted as Co0.2-VOOH) exhibits a unique sheet-like morphology, resulting in the high exposure of catalytically active sites. When used as the bifunctional catalyst, Co0.2-VOOH can achieve a current density of 10 mA cm-2 at the overpotentials of 210 mV for water oxidation and 130 mV for hydrogen generation, respectively. Notably, it only requires low cell voltages of 1.57 and 1.74 V to drive the catalytic current densities of 10 and 100 mA cm-2 during the water splitting process. This work significantly indicates that cobalt-vanadium based materials are promising alternatives for overall water splitting.

RESUMEN

Lowering the dimension of transition metal dichalcogenides is an efficient approach to expose more S-edge-sites. Here, zero-dimensional MoS2 and WS2 nanodots are successfully prepared with the assistance of a template of NiNi Prussian blue analogue nanoplates. The novel hybrids exhibit highly efficient and stable catalytic ability for the hydrogen evolution reaction.

RESUMEN

Electrochemical splitting of water has been viewed as a highly efficient technique to produce clean hydrogen and oxygen energy. However, designing inexpensive multifunctional electrocatalysts with high performance is a great challenge. Here, a unique three-dimensional catalyst of self-interconnected porous Ni-Co disulfide networks grown on carbon cloth [(Ni0.33Co0.67)S2 nanowires (NWs)/CC] was prepared by a facile hydrothermal method coupled with further low-temperature sulfuration strategy. As a bifunctional electrocatalyst, (Ni0.33Co0.67)S2 NWs/CC exhibits a remarkable activity to catalyze both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). To drive a current density of 100 mA cm-2, (Ni0.33Co0.67)S2 NWs/CC needs the overpotentials of 156 mV in 0.5 M H2SO4 solution and 334 mV in 1.0 M KOH solution for HER, respectively. Moreover, when used as a catalyst of OER, (Ni0.33Co0.67)S2 NWs/CC needs an overpotential of 295 mV to produce a current density of 100 mA cm-2. The excellent electrochemical properties are mainly attributed to the synergetic catalysis of a Ni-Co-based bimetallic disulfide, the porous network structure, and the high conduction of CC. Moreover, the two-electrode alkaline water-splitting system constructed by (Ni0.33Co0.67)S2 NWs/CC only needs a low cell voltage of 1.57 V to approach 10 mA cm-2. This work offers more new insights for the design and preparation of the non-noble metal catalysts based on transition metal sulfides with excellent electrocatalytic performance in overall water splitting.