Kinetics and mechanistic analysis of particles decontamination from abattoir wastewater (ABW) using novel Fish Bone Chito-protein (FBC)

Abstract Wastewater from slaughter houses (abattoirs) has been a problem in Nigeria. It is complex and difficult to treat. The potentials of novel Fish Bone Chito-protein (FBC) successfully extracted through de-proteinization of Fish Bone Flour (FBF) were explored for the reduction of particle load in abattoir wastewater. Extracted FBC sample was analysed via proximate analysis and instrumental characterizations viz: X-ray Fluorescence (XRF) analysis, Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectrophotoscopic Analysis (FTIR). Influences of coagulant dosage, pH, settling time and temperature were studied. The rate of particle uptake was studied using seven kinetic models. Proximate characterization of FBC revealed that it contains 24% protein, 43% carbohydrate and other components in trace values. Before treatment, abattoir wastewater contains (563 mg/L) suspended particles in excess of the national discharge standard. 92% of the particle load was removed after the coagulation treatment with 1.5g of FBC, after 35 min at pH 2, and 40 °C. BOD removal of 58% was also obtained at the same conditions. The best kinetics model selection was done between Pseudo Second Order (PSO) and fractional power (FP) kinetic model via one way statistical mean comparison using ANOVA and turkey pairwise p-values. The ANOVA p-value for pseudo second order (0.001) was found to be ˂ 0.005 (model significance alpha value). Also, the difference between the adjusted and predicted R2 value (0.0018) was less than 0.2. Thus, pseudo second order described the kinetic data with precision. The mechanistic pathway analysis for the process particle uptake was governed by intra-particle diffusion and film/surface diffusion. The results summarized indicate that fish bones are no waste, FBF is good source of coagulant.