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Human-induced changes in water consumption and global warming are likely to reduce the species richness of freshwater ecosystems. So far, these impacts have not been addressed in the context of life cycle assessment (LCA). Here, we derived characterization factors for water consumption and global warming based on freshwater fish species loss. Calculation of characterization factors for potential freshwater fish losses from water consumption were estimated using a generic species-river discharge curve for 214 global river basins. We also derived characterization factors for potential freshwater fish species losses per unit of greenhouse gas emission. Based on five global climate scenarios, characterization factors for 63 greenhouse gas emissions were calculated. Depending on the river considered, characterization factors for water consumption can differ up to 3 orders of magnitude. Characterization factors for greenhouse gas emissions can vary up to 5 orders of magnitude, depending on the atmospheric residence time and radiative forcing efficiency of greenhouse gas emissions. An emission of 1 ton of CO₂ is expected to cause the same impact on potential fish species disappearance as the water consumption of 10-1000 m³, depending on the river basin considered. Our results make it possible to compare the impact of water consumption with greenhouse gas emissions.

In this study, two biomass-based adsorbents were used as new precursors for optimizing synthesis conditions of a cost-effective powdered activated carbon (PAC). The PAC removed dyes from an aqueous solution using carbonization and activation by KOH, NaOH, and H2SO4. The optimum synthesis, activation temperature, time and impregnation ratio, removal rate, and uptake capacity were determined. The optimum PAC was analyzed and characterized using Fourier-transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), a field emission scanning electron microscope (FESEM), Zeta potential, and Raman spectroscopy. Morphological studies showed single-layered planes with highly porous surfaces, especially PAC activated by NaOH and H2SO4. The results showed that the experimental data were well-fitted with a pseudo-second-order model. Based on Langmuir isotherm, the maximum adsorption capacity for removing methylene blue (MB) was 769.23 mg g−1 and 458.43 mg g−1 for congo red (CR). Based on the isotherm models, more than one mechanism was involved in the adsorption process, monolayer for the anionic dye and multilayer for the cationic dye. Elovich and intraparticle diffusion kinetic models showed that rubber seed shells (RSS) has higher α values with a greater tendency to adsorb dyes compared to rubber seed (RS). A thermodynamic study showed that both dyes’ adsorption process was spontaneous and exothermic due to the negative values of the enthalpy (ΔH) and Gibbs free energy (ΔG). The change in removal efficiency of adsorbent for regeneration study was observed in the seventh cycles, with a 3% decline in the CR and 2% decline in MB removal performance. This study showed that the presence of functional groups and active sites on the produced adsorbent (hydroxyl, alkoxy, carboxyl, and π − π) contributed to its considerable affinity for adsorption in dye removal. Therefore, the optimum PAC can serve as efficient and cost-effective adsorbents to remove dyes from industrial wastewater.