The lack of quality material in today's rocks has led to the search for other sources. The possibility of using ash fly, a byproduct of the commercial sector, as a substitute for good mixing has been investigated in this study. This article presents the results of a research experiment conducted to evaluate the strength of concrete with fly ash instead of natural sand for 45 alternating wet-dry cycles. Consider 0%, 10%, 20%, 30%, 40%, 50%, 60%, 70% and 80% replacement of fine aggregate with fly ash and subject the concrete to 45 alternate wet-dry cycles. According to IS standards, various mechanical properties of strength tests such as compressive, tensile, bending, shear and impact strength are studied in this research work. Experimental results show that the strength of ordinary concrete with fly ash obtained from natural sand greatly increases in the dry-wet transition. For this reason, it is possible to use fly ash in wet and dry transitions by combining well and it can be used effectively in concrete.

Low-cost adsorbents derived from agricultural and livestock waste offer a sustainable approach to wastewater remediation. In this study, a material derived from cow dung ash (SMCDA) was prepared through a simple waste-valorization route without chemical activation and evaluated for the removal of methylene blue (MB) from aqueous solution. X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, Brunauer–Emmett–Teller analysis, and zeta-potential measurements were used to characterize the mineral composition, surface functional groups, morphology, pore structure, and surface charge of SMCDA. Batch adsorption experiments examined the effects of solution pH, adsorbent dosage, initial MB concentration, contact time, and temperature. The highest removal efficiency, 97.33%, was obtained at pH 8 with an SMCDA dosage of 1000 mg L⁻¹. Equilibrium data were fitted using seven isotherm models and evaluated using multiple statistical criteria and Multi-Objective Optimization by Ratio Analysis (MOORA). The Freundlich model achieved the highest MOORA ranking and predicted an equilibrium adsorption capacity of 13.944 mg g⁻¹ at the highest concentration investigated, which is close to the experimental value of 14.425 mg g⁻¹. The results are consistent with heterogeneous adsorption involving electrostatic attraction, possible π–π interactions, hydrogen bonding, and pore filling. These findings demonstrate the potential of cow dung ash as a low-cost adsorbent prepared without hazardous chemical activating agents.