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A comparative study on mechanical, thermodynamic, electronic, and optical properties has been performed on various compounds having an ABO3, where A = Ba, Ca, Sr and B = Ce, Ti, Zr, perovskite structure using first-principles calculations. These materials’ properties have been thoroughly investigated for their ground states under the same computational parameters. The computed lattice parameters in the ground state agreed with other theoretical studies. Elastic moduli, ductility or brittleness, elastic anisotropy, mechanical stability, and stiffness of solid materials are studied. Enthalpy (H), entropy (S), and free energy (F) were reported from the vibrational properties of the materials. The temperature-dependent heat capacity and Debye temperature are investigated. The electronic band structure as a function of energy, of different perovskite structures at the ground state, is also studied. From this study, the ABO3 perovskite has emerged as the most promising material for applications in optoelectronics, photonics, and mechanical and thermoelectric devices.

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In this research, a hybrid anaerobic baffled reactor (HABR) configuration was proposed consisting of a front sedimentation chamber and four regular baffled chambers followed by two floated filter media chambers for the treatment of domestic wastewater. Performance comparison of uninsulated and insulated HABRs was carried out operating at warm temperature (18.6–37.6 °C) under variable HRTs (30 h and 20 h). The study suggests that almost similar chemical oxygen demand (91% vs 88%), total suspended solids (90% vs 95%), turbidity (98% vs 97%), and volatile suspended solids (90% vs 93%) removal efficiencies were obtained for uninsulated and insulated HABRs. Higher removal of total nitrogen (TN) of 41%, NH4+-N of 44%, and NO3−-N of 91% were achieved by the insulated HABR compared to TN of 37%, NH4+-N of 36%, and NO3−-N of 84% by the uninsulated HABR, whereas lower PO43− removal efficiency of 17% was found in the insulated HABR compared to 24% in the uninsulated HABR. This indicated insulation increased nitrogen removal efficiencies by 4% for TN, 8% for NH4+-N and 7% for NO3−-N, but decreased PO43−removal efficiency by 7%.

The regular practice of using sodium chloride to preserve raw animal skin triggers increasing salinity and total dissolved solids (TDS) in the surface and groundwater during rehydration soaking operations. The process disrupts the lives of animals, plants, and human beings. This paper is focused on the phytobased short-term preservation of goatskin to reduce salinity in tannery soaking operations. The indigenous Persicaria hydropiper leaf was investigated to assess the preservation of animal skin to diminish salinity and TDS of tannery soaking wastewater. Methanol extracted leaf was characterized by GC-MS and FTIR for chemical composition analysis and a liated functional groups. Fresh goatskins were preserved at the preliminary, laboratory, and pilot-scale scenarios to establish the best possible mixture, monitor the moisture and nitrogen content, shrinkage temperature, microorganism analysis, and pollution load at each level. The processed leathers derived from the preserved skins with an optimal mixture of 10% leaf paste with 8% salt and conventional 50% salt were tested for their physical strength.Finally, the modi cation in ber structure due to the varieties of preserving chemicals was evaluated through a scanning electron microscope (SEM) and detected insigni cant variation of leather bers. The ndings reported in this study can be applied to the industrial level and remove certain amounts of salinity and TDS from tannery soaking wastewater. HighlightsLeaf paste of Persicaria hydropiper is used for eco-friendly goatskin preservation Signi cant reduction of chloride, TDS, BOD and COD in soaking wastewater Fiber structures of optimized experimental and control leathers are similar

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The current technologies of algal biofuels production and wastewater treatment (e.g., aerobic) process are still in question, due to the significant amount of fresh water and nutrients requirements for microalgae cultivation, and negative energy balance in both processes, especially when considered in the context of developing counties around the world. In this research, a simplistic sustainable approach of algal biofuels production from wastewater was proposed using a Hybrid Anaerobic Baffled Reactor (HABR) and Photobioreactor (PBR) system. The study suggests that the HABR was capable of removing most of the organic and solid (>90% COD and TSS removal) from wastewater, and produced a healthy feedstock (high N: P = 3:1) for microalgae cultivation in PBRs for biofuels production. A co-culture of Chlorella vulgaris, Chlorella sorokiniana, and Scenedesmus simris002 showed high lipid content up to 44.1%; and the dominant FAMEs composition (C16-C18) of 87.9% in produced biofuels. Perhaps, this proposed low-cost technological approach (e.g., HABR-PBR system) would connect the currently broken link of sustainable bioenergy generation and wastewater treatment pathway for developing countries.

Hydrodynamic performance of a biological reactor is an important design concern since it directly affects the treatment efficiency. In this research, a hybrid anaerobic baffled reactor (HABR) was proposed with improved design concepts and principles. The HABR consisted of a front sedimentation chamber, four regular baffled chambers followed by two floated filter media chambers. The effects of operating variables 5–20 hr hydraulic retention time (HRT) and 10–40 °C of influent temperature, as well as their interactive effects, on the hydrodynamic behaviour were investigated by residence time distributions study and response surface methodology. The study suggests that the hydrodynamic performance is greatly influenced by the number of chambers in the reactor rather than HRT and influent temperature. The influence of HRT and feed temperature were mainly observed on the front chambers (1–4) rather than rear chambers (5–7). The optimum reactor performance – low dead space (<10%), excellent hydraulic efficiency (>0.75), and intermediate mixing pattern (Peclet number > 10) – were achieved using the proposed HABR with more than five chambers.