Fiber reinforced composites were in use since ancient times. Due to the disadvantage of the synthetic and fiber glass as reinforcement, the use of fiber reinforced composite gained the attention of the young scientists. The review article explores the use of variable fiber as reinforcement in composites. With the advancement of science and technology the new means of characterization and evaluation of physico-chemico-thermo-mechanical properties of the composite have been used that have explored the new horizon of utilizing them for various applications

The term ‘composite’ in material science refers to a material made up of a matrix containing reinforcing agents. Reinforcement is the part of the composite that provides strength, stiffness, and the ability to carry a load. Wood is a natural composite of cellulose fibers in a matrix of lignin. In manufacturing, fibers are the most commonly used reinforcement that yields Fiber Reinforced Composite (FRC). The reinforcement is embedded into the matrix. Common matrixes include mud (wattle and daub), cement (concrete), polymers (fiber reinforced plastics), metals and ceramics. The most common polymer-based composite materials include fiberglass, carbon fiber and kevlar. Fiberglass is probably one of the most familiar reinforcing composite materials that were introduced in 1940, consisting of glass fiber reinforcement of unsaturated polyester matrix [1-3]. This glass fiber had numerous drawbacks that led to search for alternate substitute as reinforcement. Fiber as reinforcement to the composite had outstanding physio-chemico-thermo-mechanical performance, durability and eco-friendly nature that highlighted and promoted its scope.

written by Journal of Chemical Engineering and Process Technology

The intention of this study was to explore the efficacy and feasibility for Cu (II) adsorption onto fixed bed column of maize tassel-PVA beads. The effects of flow rate and bed height were explored. The Thomas, Adams and Bohart and Yoon-Nelson models were analysed to evaluate the column adsorption performance. The adsorption rate constant and correlation coefficient associated to each model for column adsorption was calculated. Thomas model indicated that increase in column height and flow rate increased the values of k_Th and q_o. Thereafter, the value of q_o decreased with decreasing bed height. With Adam-Bohart model, the values of k_AB increased as the flow rate and the bed height increased and continued to increase with decrease in bed height. However, the value of N_o first increased with increase in flow rate and bed height, but later decreased with decrease in bed height. This suggests that the overall system kinetics may have been influenced by external mass transfer, particularly in the initial part of adsorption in the column. In the case of Yoon-Nelson model, the rate constant k_YN and τ increased with increase in bed height and flow rate. However, decrease in bed height at a flow rate of 2.33 × 10^-3 L min-1 resulted in an increase in τ while the values of k_YN decreased. The three models gave high values of R² (0.9694-0.98920), although the Adam-Bohart model values were, on average, the least. Therefore, it can be said that both the Thomas and Yoon-Nelson models describe the behavior of the adsorption of Cu (II) in a fixed-bed column better than Adam-Bohart.

written by Journal of Chemical Engineering and Process Technology

The use of flotation technique for the recovery of calcium carbonate (CaCO3) from wastewater treatment sludge was investigated in this study. The parameters that were investigated included dosage of floating agents (sodium oleate and sunlight dish liquid) and the percentage solids of the slurry. The experiments were performed by floating sieved and un-sieved materials and CaCO3 was determined for both conditions as well as from tailings.

Initial CaCO3 analysis for the bulk material indicated that sieved and un-sieved materials had 63.4% and 32.9% CaCO3 content by weight respectively. The modification of pH was effected by dosing 1g NaCO3 to both 1000 g of sieved and un-sieved materials which was sufficient to raise the pH of the slurry to 9.5. A lower average recovery of 2.33% was observed on un-sieved material after using sodium oleate as a collector when compared to sunlight liquid of 31.6%. Therefore, it was concluded that for un-sieved material sunlight dishwashing liquid was a better collector compared to the latter. The results of this study proved that there is great potential of recovering commercial grade limestone from wastewater sludge.

written by Journal of Chemical Engineering and Process Technology