The potentials of natural coagulants (egg shell and fish scale) in the treatment of vegetable oil industrial wastewater were investigated. The coagulants were characterized to determine their chemical compositions, functional groups and morphology using proximate analysis method, Fourier Infra-red spectroscope (FTIR) and Scanning Electron Microscope (SEM) respectively. The industrial wastewater was equally characterized to determine its heavy metal composition and physico-chemical properties. The effects of various process parameters such as pH, coagulants dosage, time and temperature were examined during the treatment of the waste water using the natural coagulants. The proximate analysis shows that Fish Scale Coagulant (FSC) contains more carbohydrate, 42.30% while Egg Shell Coagulant (ESC) has protein content of 39.65%. It was discovered that the coagulating properties of both FSC and ESC improve after extraction due to presence of isocyanates, isothiocyadilimides, azides, ketenes, aldehydes and ketone. The turbidity of the wastewater was very high (365NTU) above the WHO recommended value. The process variables have significant effects on the coagulation with best removal efficiency of 88.54% for ESC and 74.12% for FSC at pH of 4.0 (ESC) and pH of 7.0(FSC); 0.5 g/L (ESC) and 0.04 g/L (FSC) coagulant dosage and temperature of 40°C. Therefore, both coagulants are effective in treating vegetable oil effluent but egg shell coagulant was found to be a better coagulant. Further research on optimization, kinetics and thermodynamics of the coagulation process using ESC and FSC should be carried out.

Remediation of crystal violet (CV) dye aqueous solution was attempted using acid activated raphia hookeri seeds (AARHS) as adsorbent. Adsorption equilibrium and kinetics of CV dye uptake onto AARHS were examined in series of experimental runs, and effects of contact time and initial CV dye concentrations were investigated at different solution temperatures (303 K, 313 K and 323 K). Equilibrium and kinetic data modeling of the adsorption process was performed using selected theoretical methods. Four different forms of Langmuir (type I, II, III and IV) and Freundlich isotherms were considered for fitting the equilibrium data while zero order, first order, pseudo-first order (PFO), second order, types I, II, III and IV pseudo-second order (PSO) and intra-particle diffusion models were selected to describe the kinetics of the adsorption process. Error functions including coefficient of determination (R2), root mean square error (RMSE), chi square (χ2) and average relative error (ARE) were employed to reveal model of best fit. Results obtained from error value computations show that the equilibrium data best followed Freundlich isotherm, which indicates multilayer adsorption of CV dye onto AARHS. The calculated Freundlich’s adsorption intensity values at different temperatures reveal the favourability of the adsorption process. PSO type I, II and IV best fitted the kinetic data compared to other investigated models. Intra-particle diffusion plots depict that the adsorption process of CV dye onto AARHS is a two-step process and also, intra-particle diffusion is not the only rate-limiting step.