Copper concentration simulation in a river by SWAT-WASP integration and its application to assessing the impacts of climate change and various remediation strategies.

The present study aimed to investigate the copper distribution in a river through the integrated utilization of the soil hydrological assessment model and water quality model. The Erren River was selected as the investigated river system because an apparent heavy metal pollution was observed. The Soil and Water Assessment Tool (SWAT) was employed to estimate the soil flux. The Water Quality Analysis Simulation Program Model (WASP) was used for water quality simulation. The copper was selected as the model chemical and scenarios of various copper effluent control measures and impacts of the heavy rainfall by climate change on copper concentration were simulated. The results showed that the aqueous copper was adsorbed to suspended solids and the high aqueous copper concentration resulted in a high copper concentration in the sediment. In dry seasons, the aqueous copper concentration increased 215% comparing to the 2006-2016 average (baseline) concentration and a 20% decrease in copper concentration in the sediment was observed due to less wash-out solid. Under the impact of enhanced rainfall by climate change, the aqueous copper concentration decreased due to the increased river flow, which also reduced the copper deposition causing the copper concentration in the sediment lower than that in the baseline condition. In the middle and downstream river sections, the copper concentration in the water and sediment phases decreased around 66% by implementing a more-stringent effluent standard. The suspended solid played a key role for copper movement in a river. The copper accumulation in the sediment might be alleviated by reducing its aqueous concentration.

Effecacy of Biejia (Carapax Trionycis) and Ezhu (Rhizoma Curcumae Phaeocaulis) couplet medicine on epithelial-mesenchymal transition, invasion and migration of MDA-MB-231 triple negative breast cancer cells via PI3K/Akt/mTOR signaling pathway.

OBJECTIVE: To investigate the efficacy of Biejia (Carapax Trionycis) and Ezhu (Rhizoma Curcumae Phaeocaulis) couplet medicine on epithelial-mesenchymal transition (EMT), invasion and migration of MDA-MB-231 triple negative breast cancer (TNBC) cells based on PI3K/Akt/mTOR signaling pathway. METHODS: MDA-MB-231 cells were treated with different medicated serum as Biejia-, Ezhu-, Biejia-Ezhu (BJ-, EZ-, BJ-EZ-) groups, intervened with no drug rat serum and paclitaxel with final concentration of 33 nM (IC50) as negative and positive control (NC and PC) groups. CCK-8 assay, scratch test, and Transwell assay were used to examine cell proliferation, invasion, and migration. The expression of E-cadherin, N-cadherin, Vimentin, MMP-2, MMP-9, PI3K, Akt, p-Akt, mTOR, and p-mTOR was determined by Western blot, and the mRNA expression of PI3K, Akt and mTOR was determined by real-time polymerase chain reaction. RESULTS: BJ-EZ group inhibited proliferation after 24, 48, and 72 h compared with the NC group (P < 0.05, < 0.01 or < 0.001) and reduced the invasion and migration of MDA-MB-231 cells (P < 0.01 or < 0.001). In addition, BJ-EZ group upregulated the expression of E-cadherin, downregulated the expression of N-cadherin, Vimentin, MMP-2, and MMP-9 (P < 0.05, P < 0.01 or P < 0.001), and inhibited the mRNA and protein expression of PI3K, Akt (p-Akt), mTOR (p-mTOR) (P < 0.05, < 0.01 or < 0.001). CONCLUSION: Biejia (Carapax Trionycis) and Ezhu (Rhizoma Curcumae Phaeocaulis) couplet medicine can inhibit the proliferation, invasion, migration and EMT of MDA-MB-231 cells through PI3K/Akt/mTOR signaling pathway, and the effect is better than that of Biejia (Carapax Trionycis) or Ezhu (Rhizoma Curcumae Phaeocaulis) alone.

Distribution of residual agricultural pesticides and their impact assessment on the survival of an endangered species.

This study aimed to assess the distribution of spent pesticides in an agro-farming area and to evaluate their impact on the ecological risk for an endangered species combing the health risk assessment concept with the modelling algorithm proposed by European Food Safety Authority (EFSA). An agricultural area in western Taiwan was chosen to investigate the ecological risk on Prionailurus bengalensis. Their ecological stability was evaluated in the context of the residuals' distribution of the spent pesticides in the investigated area. The pesticide residues accumulated and correlated highly to the adverse health impact on the leopard cat. In the present study, 67 pesticides were detected from 79 collected soil samples. The hazard index (HI) was found related to land use patterns and the HI values in Yuanli and Zhuolan were significantly higher than those in the other areas, increasing poisoning probability of the leopard cat. The locations of agro-chemical utilization were highly overlapped with leopard cats' activity zone, supporting the hypothesis that pesticide residues posed a potential threat to the leopard cats' health. The proposed risk assessment framework was capable of estimating the risk caused by pesticide residues and no similar study has been reported before.

Composition-oriented estimation of biogas production from major culinary wastes in an anaerobic bioreactor and its associated CO2 reduction potential.

Despite the wide applications of dry anaerobic digestion (AD), a number of fundamental issues, such as composition-oriented estimation of biogas production and CO2 reduction potential, were not well understood yet. The objective of this study was to establish composition-oriented models for prediction of biogas production and the associated shift of microbial communities. Three important factors regarding feedstock, including loading, carbon-to-nitrogen ratio, and solid-to-liquid ratio, were found to significantly affect the biogas production. The biogas production and digestion kinetics were evaluated with the response surface methodology. The major contribution to biogas production was found to be hydrogenotrophic methanogens (82.6 ± 0.4%). The net CO2 reduction potential was assessed from the life-cycle approach, and a substantial amount of CO2 generation (i.e., 2.8-6.7 tonne/tonne-VS) could be reduced by AD, compared to incineration, revealing that dry AD for food waste treatment should be one of the essential practices in the portfolio of global CO2 mitigation.

Kinetic study and performance comparison of TiO2-mediated visible-light-responsive photocatalysts for the inactivation of Aspergillus niger.

Fungi are highly survived with exceptional resistance to environmental stress. Conventional fungicides are quite efficient, but the increase in use raises severe environmental problems. In this study, environmentally friendly TiO2-mediated visible-light-responsive photocatalysts, namely N-TiO2, N-T-TiO2, C-TiO2, and Pd-C-TiO2, were used to compare the performance of disinfecting a mold fungi Aspergillus niger. Key parameters, including photocatalyst dosage, the initial fungal concentration, and visible-light intensity, affecting the disinfecting process, was investigated. A new developed Light-responsive Modified Hom's (LMH) kinetic model incorporating visible-light intensity and photocatalyst light-absorption coefficient was firstly used to predict such photocatalytic process in fungal inactivation. Among the photocatalysts, Pd-C-TiO2 showed the highest inactivation performance against fungi, followed by C-TiO2, N-T-TiO2, and N-TiO2. In general, inactivation increased with increasing photocatalyst dosage and light intensity while decreased with increasing initial fungal concentration. For kinetic modeling, the LMH model supports the hypothesis that photocatalyst performance toward visible-light-driven fungal inactivation primarily depends on the light-absorption capacity of the photocatalyst. In conclusion, mold fungi Aspergillus niger are effectively disinfected by TiO2-mediated visible-light-responsive photocatalysts, and such fungal inactivation process could be predicted by LMH kinetic model.