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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 R 2 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.

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.

Highlights DM drug was introduced as a novel corrosion inhibitor. Polarization measurements signify that DM drug acted as a mixed mode inhibitor. Adsorption mode best reflect in Langmuir isotherm. MD-simulation reveals the vital role of active sites of DM molecule in their adsorption. ANFIS best predicted the interactive effects between the input and output response.

Abattoir wastewater generated from various meat processing operations in several developing countries pose a serious threat to the environment. Consequently, there is urgent need to reduce the impact of environmental pollution from it. Coagulation techniques have been recommended and used by many researchers successfully in treating wastewater, therefore an investigation of possible use of chito-protein extracted from crab shell (locally sourced) was used as a coagulant for treating abattoir wastewater. Coagulation experiments were carried out using jar-test procedure to investigate the influence of pH, time of settling, temperature and adsorbent dosage for coagulation of BOD, COD, Turbidity and Colour from the wastewater sample. To determine the interaction effect of the various process variables, Response Surface Method (RSM) was used in the optimization of the process variables. To determine the effectiveness of the coagulant, pre and post characterization of the wastewater samples were undertaken, the result of the post characterization of the wastewater sample indicated that most of the water quality parameters except Iron were within WHO standard. The Total Suspended Solid (TSS), for instance stood at 564.6 mg/L and 29 mg/L respectively for pre and post characterisation, the value of 29 mg/L of the post characterization was below the WHO recommended value of 30 mg/L. The predicted responses and the experimental values correlated significantly, an indicator that RSM optimization method used in this study is suitable in modelling the process variables. The result of the study further shows that optimum process variable is dependent on the solution pH (acidic), coagulant dosage of 2–3g, settling time of 25–30 min and operating temperature from 323K to 333K. The coagulant used in this study, when compared with previous studies have shown to have strong potential for use as a coagulant and as an alternative to chemical coagulants in the treatment of abattoir wastewater.

Waste materials such as periwinkle shells (PS) and waste cooking oil (WCO) were considered as heterogeneous catalyst and renewable feedstock for biodiesel production respectively in line with the current search for alternatives of the environmentally unfriendly and gradually depleting fossil fuel. PS were size reduced and calcined at 673K for 4 hours to remove carbonaceous and volatile matter in the sample. Physicochemical analyses on the WCO revealed high FFA (2.81%) therefore the need for esterification (0.42%). One factor at a time (OFAT) results show that methanol to oil ratio, catalyst loading, reaction temperature and time had significant effect on the biodisel yield. The transesterification reaction kinetics data was modelled using the zero-order, pseudo-first order and pseudo-second order models. The results presented from the error functions: root mean square error (RMSE), chi-square (χ2), mean absolute error(MAE) and coefficient of determination (R2) adjudged that the pseudo-first order model best described the process. An activation energy of 16.47 KJ/mol was obtained. Gas chromatography result revealed that a biodiesel yield of 73.92% was achieved at 8:1 methanol to oil ratio, 1% catalyst loading, 300 rpm stirring speed, 333K reaction temperature and 90 minutes contact time. The findings suggest potentials of PS as a viable catalyst for biodiesel production.

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