Quantification, distribution, and effects of di (2-ethylhexyl) phthalate contamination: Risk analysis and mitigation strategies in urban environment

Ecologically sustainable removal of pharmaceuticals: A mechanistic study of bismuth sulfide-graphene oxide/silver nanocomposite

Bismuth sulfide nanoparticles (BiS NPs) were synthesized via the hydrothermal method, and reduced graphene oxide(rGO) and silver nanoparticles (Ag), which acted as substrates, have prepared using the chemical reduction method. The synthesized nanoparticles have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible spectroscopy, and photoluminescence spectroscopy. Commercially available paracetamol-500 mg (PAM) and aspirin-300 mg (ASP) were selected for photodegradation under visible light using the as-prepared composites in an aqueous solution. Photoluminescence spectroscopy was used to detect PAM and ASP using the photo-excited electron transfer (PET) process, and the limit of detection (LOD) has obtained for PAM(8.70 ppm) and ASP(4.43 ppm) with a sensitivity of 0.9954 and 0.8002, respectively. Fourier transform infrared spectroscopy (FTIR) was used to analyze the before and after degradation products and to confirm the disintegrated products such as -COOH and -CH- both before and after disintegration.. The experimental data were found to fit well with the Freundlich isotherm, suggesting that the as-prepared nanocomposites exhibited a heterogeneous nature for PAM (5119 mg/L), and the pseudo-first-order kinetic model suggests ASP (1030 mg/L) with R2 values of 0.9119 and 0.7075. The risk assessment analysis of PAM was 9.823 μg/L(RQ > 1) and that of ASP was 0.2106 μg/L(RQ < 1), indicating that PAM has a higher potential risk than ASP. The demographic data of the participants indicated that PAM was the most stockpiled medicine at home; this work also encompasses the action of a single PAM and ASP tablet toward the environment, if it is accidently disposed of improperly could create massive water/soil pollution; hence, the care/duty of each person should follow the proper disposal of medical waste because we cannot replace this environment.

Spatiotemporal variation and risk assessment of phthalate acid esters (PAEs) in surface water of the Yangtze River Basin, China

Spatiotemporal variation, potential sources, and risk assessment of phthalate acid esters (PAEs) in surface water of the Yangtze River Basin were investigated. Total cumulative concentrations of 15 PAEs (Σ₁₅PAEs) ranged from 1594.47 ng·L^-1 to 5155.50 ng·L^-1, and the dominant components were di (2-ethylhexyl) phthalate (DEHP) (35.9-60.1%), dibutyl phthalate (DBP) (16.6-38.8%), and diisobutyl phthalate (DIBP) (6.7-18.2%). Σ₁₅PAEs in surface water showed a trend of normal season > wet season > dry season. Σ₁₅PAEs increased from the upstream (2341.7 ± 428.5 ng·L^-1) to the mid- and downstream (3892.1 ± 842.8 and 2504.3 ± 355.9 ng·L^-1, respectively), indicating the influence from production and consumptions of plasticizer-containing items. PAEs additives emission from daily necessities (28.9-62.3%) and construction and industrial production (18.7-31.2%) were the dominant sources of PAEs in this study. The risk quotient (RQ) method was employed to assess the potential ecological risk of specific components. High ecological risk of DEHP to the sensitive algae and crustacean, together with moderate ecological risk of DEHP and DIBP to the sensitive fish species were found in surface water regardless of the region and season. The spatial distribution of RQ values showed an increasing trend from the upstream to the midstream and downstream of the Yangtze River, indicating the influences from regional urbanization and industrialization levels.

Method development using chemometric tools for determination of endocrine-disrupting chemicals in bottled mineral waters

A simple method was developed to determine 14 endocrine-disrupting chemicals (EDCs) in bottled waters, based on dispersive micro-solid phase extraction (d-µ-SPE) and liquid chromatography-mass spectrometry (LC-MS). Extraction was optimized using 2 ^k-1 factorial and Doehlert experimental designs. Optimized conditions were 80 mg C18, 25 min extraction at 1000 rpm, and 6 min desorption time. Repeatability was below 17 % for all EDCs. LOD and LOQ varied from 1.60 ng L^-1 (estradiol, E2) to 23.2 ng L^-1 (dimethylphthalate, DMP) and from 5.33 ng L^-1 (E2) to 77.3 ng L^-1 (DMP). We found DMP and bisphenol A (BPA) in samples after the heat treatment. DMP was up to 58.7 µg L^-1, while BPA was up to 1.34 µg L^-1. Tolerance of daily intake (TDI) for DMP were 2.50-2.94 µg kg^-1 day^-1 (children) and 1.43-1.68 µg kg^-1 day^-1 (adults). TDI for BPA were 0.03-0.07 µg kg^-1 day^-1 (children) and 0.01-0.04 µg kg^-1 day^-1 (adults).