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Treatment of pulp and paper mill wastewater using ultrafiltration (UF) membranes was investigated in this study. A Taguchi experimental design was implemented for design of the experiments to investigate optimum operating conditions that achieve higher removal of pollutants and lower membrane fouling. Four factors at three different levels were considered for the experimental design, namely, pH, temperature, transmembrane pressure, and volume reduction factor (VRF). Under the optimized conditions (pH 10, temperature 25 °C, transmembrane pressure 6 bar, and VRF 3), a 35% flux decline caused by fouling occurred. Higher rejections were observed for total hardness (83%), sulfate (97%), spectral absorption coefficient (SAC 254 ) (95%), and chemical oxygen demand (COD) (89%), but not for conductivity (50%), under these conditions. From the analysis of variance (ANOVA), it was determined that the factor of pH made the greatest contribution to response parameters. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) analyses showed that membrane fouling occurring on the membrane surface and within pores decreased by optimizing the operating conditions. The Taguchi method was successfully applied to find the optimum conditions for the treatment of pulp and paper mill wastewater using the UF process.

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The pyrolysis of sewage sludge (SS) and olive mill waste (OMW) was carried out under nitrogen atmosphere and analyzed thermogravimetric and scanning electron microscopy micrographs. Removal capacity of pyrolyzed cokes was measured by humic acid solution. Humic substances can react with chlorine to produce carcinogens in drinking water. Activated carbon can be used as an effective treatment method to remove humic substances from water to prior to disinfection by chlorination. Olive mill waste, an agricultural byproduct and sewage sludge were used to produce activated carbon by pyrolysis with the addition of zinc chloride to enhance the reaction. Activated carbon was also produced using olive mill waste and sewage sludge. Both of them were compared to a commercially-available activated carbon product. Optimum pyrolysis conditions and concentration of the activating agent were identified. The equilibrium parameter model of the Freundlich isotherm and Langmuir isotherm was applied to the adsorption data, and the efficiency of pyrolyzed coke was determined. Activated carbon produced from olive waste material had a lower specific surface area (437.92 m 2 /g) than activated carbon produced from sewage sludge (814.48 m 2 /g). While both of these were lower than the surface area of a commercially activated carbon, the latter fell within the expected range of commercial products, thus suggesting an effective means of producing activated carbon while reducing sewage waste disposal costs.