This study aims to comprehensively investigate the current advances in water treatment technologies for the elimination of heavy metals using biomass-based adsorbents. The enhancement of adsorption capacity in biomass materials is achieved through surface modification, which increases their porosity and surface area. The study therefore focuses on the impact of different surface modification techniques on the adsorption capacity, as well as the evaluation of adsorptive removal techniques and the analysis of various isotherm and kinetics models applied to heavy metal contaminants. The utilization of kinetic and isotherm models in heavy metal sorption is crucial as it provides a theoretical background to understand and predict the removal efficiency of different adsorbent materials. In contrast to previous studies, this research examines a wide range of adsorbent materials, providing a comprehensive understanding of their efficacy in removing heavy metals from wastewater. The study also delves into the theoretical foundations of the isotherm and kinetics models, highlighting their strengths, limitations, and effectiveness in describing the performance of the adsorbents. Moreover, the study sheds light on the regenerability of adsorbents and the potential for their engineering applications. Valuable insights into the state-of-the-art methods for heavy metal wastewater cleanup and the resources required for future developments were discussed.

Wood is a unique material for making musical instruments and is used to make West African talking drums, whose pitch can be regulated depending upon how the player strikes the head of drum and changes its tension. Additionally, talking drum manufacturers have certain wood preferences, and in the absence of preferred species, they use supposedly unsuitable woods. Therefore, there is a need to examine wood traits in relation to the pitch of a talking drum. This study was designed to determine the existing relationship between selected wood traits and the frequency of talking drums made from A. robusta wood. Three A. robusta trees were obtained from Onigambari Forest Reserve. From each tree, three bolts of 50 cm in length were obtained from the base, middle, and top of the tree to determine selected properties (moisture content ( MC ), wood basic density ( WBD ), modulus of elasticity ( MOE ), modulus of rupture ( MOR ), and manufacturing of talking drums). A spectrum analyzer was used to analyze the sound frequency of the talking drums at three pitch levels (high, medium, low). A completely randomized block design was used and the data obtained was analyzed using descriptive statistics, ANOVA , and correlation analyses at α _0.05 . Sound frequency was not significant along sampling height, but was significant at pitch levels. Additionally, the correlation analysis between wood traits and sound frequency was not significant. Thus, wood cannot be recommended for talking drums’ optimal acoustic performance based on wood traits alone.

Assessing intrinsic wood qualities such as modulus of elasticity and internal decay in trees and logs can be challenging. However, acoustic technologies have been investigated for a possible solution. This paper reviews available literature on non-destructive acoustic methods for assessing wood quality, both in tree and log form. The paper further reviews the effects of silvicultural practices (such as thinning and pruning) on wood quality assessed by non-destructive acoustic methods. We documented some of the benefits of application of non-destructive acoustic methods on wood quality of trees and logs. The acoustic velocity of a tree (V_T) or log (V_L) of the propagated waves and wood density can be used to determine the Dynamic Modulus of Elasticity (MOEd). Thinning was reported to affect V_T/V_L and MOEd negatively. Acoustic tomography methods were equally found to have good accuracy in detecting the location and extent of wood decay in standing trees and logs.

This study aimed at estimating MOE of Boscia augustifolia wood using non-destructive longitudinal vibration acoustic method with the view to examining its reliability. Three trees of B. augustifolia were obtained, and samples of $20\times 20\times 300\mathrm{m}{\mathrm{m}}^3$ were collected for dynamic and static bending testing of the wood’s elasticity. The samples were stored for a month prior testing after oven dried. Mean values of dynamic (dMOE) and static modulus of elasticity (sMOE) of B. augustifolia wood obtained were 6.908 ± 0.7525 GPa and 6.9148 ± 0.5870 GPa, respectively. Analysis done showed no significant difference between the values from the two methods while regression model was significant with 0.65 coefficient of determination. Strong correlation of 0.81 was observed between the dMOE and sMOE. Meanwhile, wood density had a correlation of 0.73 and 0.50 with dMOE and sMOE respectively. The acoustic method used was considered reliable for determining MOE of the wood.

This paper endeavoured to assess the acoustic properties of talking drums made from hourglass shells of different geometric shapes out of Gmelina arborea wood with the view of assessing and improving the acoustic properties of the talking drum. Talking drums from 6 different geometric shapes were manufactured from base wood of G. arborea. The lowest and highest means were 172.10 and 175.75 HZ for resonance frequency, 43.67 and 46.50 dB for amplitude, 635.00 and 743.33 ms for sound damping time, 0.06 and 0.14 for best timbre harmonic, 0.30 and 0.41 for poorest harmonic, respectively. Conclusively, talking drums made from these hourglass shells compared differently and it was found that hourglass shell making the talking drum and tension on the rope influences the drum’s acoustic performance.