Techno-economic feasibility of advanced aquaporin-based hollow fiber forward osmosis membrane in industrial wastewater treatment

Textile and tannery industries are major contributors to water pollution worldwide. This study investigates the technical and economic feasibility of treating textile and tannery wastewaters using a biomimetic hollow fiber Forward Osmosis (FO) membrane whose active layer is integrated with polyamide-TFC materials and aquaporin proteins. Real industrial compositions from the Indian textile and tannery industries were used to replicate wastewaters in the laboratory. Experiments were performed with sodium chloride as draw solution and the performance parameters of water flux (WF), specific reverse solute flux (SRSF), recovery and rejection were investigated by varying operating parameters of temperature, concentration difference, and flow rates. Fouling propensity and economic feasibility of treating these wastewaters were also investigated. Results showed that textile wastewater was treated more effectively than tannery wastewater in terms of high WF (12.4 LMH), recovery (14.1 %) and rejection (98 %) with a low SRSF (0.38 g/L). Fouling tests showed that the fouling was reversible in both cases and around 97 % of initial WF can be recovered. Annualized production cost of clean water was comparatively lower (0.42 $/m3) for treating textile wastewater. Thus, the biomimetic membrane has great potential to treat industrial wastewater and protect the environment

A hybrid approach of NiP coating and STF impregnation of UHMWPE fabric for conductive soft body armor

To enhance the ballistic impact performance and impart electrical conductivity into soft armor material made up of UHMWPE fabric, a novel hybrid technique has been devised and incorporated. Initially, the NiP layer was deposited on the UHMWPE fabric surface through the electroless process, subsequently, it was impregnated in the shear thickening fluid (STF) based on nano-silica (40 wt%). The morphology, functional groups, phase structure, thermal stability, breaking load, inter-yarn friction, electro-heating, and ballistic impact performance of the neat (UHM), STF impregnated (UHM-STF), NiP coated(UHM/NiP), and NiP coated STF impregnated (UHM/NiP-STF) fabrics are detailed. The NiP coating enhanced the ballistic impact performance, and thermal stability, and became electrically conductive compared to neat fabric. The ballistic impact test confirmed the enhancement in the energy absorption of UHM-STF (30.84%), UHM/NiP(18.37%), and UHM/NiP-STF(54.82%) compared to UHM. The hybrid technique (UHM/NiP-STF) exhibited higher inter-yarn friction (53.79%) and ballistic impact energy absorption (18.43%) compared to UHM-STF. The significant rise in the impact energy absorption of the UHM/NiP-STF can be ascribed to the synergetic effect of enhanced inter-yarn friction induced by the NiP-coated layer and the shear thickening behavior exhibited by STF. The NiP-coated and STF-impregnated fabrics present a promising prospect for the advancement of soft body armor materials with multifunctional ability

Friction-wear behavior of shot peened aluminium 7075-T651 alloy

20-26The present study reports the friction-wear behavior of un-peened and shot peened aluminium 7075-T651 alloy against aluminium 7075-T651 alloy in dry sliding condition. Shot peening was done using CI steel ball (40-45 HRC) with 0.6 mm diameter. Phase Structure, hardness, compressive residual stress, surface morphology and surface features are characterized using X-ray diffractometer (XRD), Vickers hardness tester, noncontact-surface profile meter and scanning electron microscope (SEM). Sliding wear test were conducted against aluminium 7075-T651 alloy in dry sliding condition at room temperature using a pin on disc apparatus. A 25% increase in the hardness was seen for shot peened aluminium 7075-T651 alloy. Shot peened aluminium 7075-T651 alloy has induced maximum compressive residual stress of -188 MPa. No new phases were formed for the shot peened aluminium 7075-T651 alloy, however, the shift in the plane is observed. There was also a drastically increase in surface roughness in spite of the peening process. Adhesive wear was the dominant wear mechanism for the un-peened specimen, whereas, it was reduced for the shot peened surfaces

Analyzing the mechanical and wear behavior of age hardening processed AZ31 magnesium composites

Abstract The usage of AZ31 magnesium alloy has been limited in tribology applications, due to low hardness and poor wear resistance. In this connection, the age-hardening process is a promising heat treatment process for enhancing mechanical strength and wear resistance. Hence, the present work aims to analyze the effect of the age-hardening process on the microstructure, mechanical and wear behavior of AZ31 Magnesium-Calcium hexaboride composites (Mg composite). Here, dry sliding wear behavior was analyzed with different loads (10, 20, and 30 N) and sliding velocity (0.4, 0.6, and 0.8 m. s−1) for a constant sliding distance of 2000m. Age hardened composites exhibited a higher hardness and compressive strength which was due to the increased volume of the secondary precipitates (Mg17Al12 and Al8Mn5). The morphology study revealed that there is an exhibition of shear bands and brittle fracture for Age hardened composites. The remarkable wear rate reduction was achieved for age hardening processed composites due to the increased load-bearing capacity induced by the presence of a high volume of secondary precipitates. Delamination wear is the dominant wear mechanism for the composites and the delaminated craters increases with increasing the load condition. Further, the elemental mapping on the collected wear debris was also used to confirm the wear mechanism.</jats:p