Intan Salwani Ahamad

A preliminary study on Jatropha curcas as coagulant in wastewater treatment

Many coagulants, mainly inorganic, are widely used in conventional water and wastewater treatment. Recent studies reported the occurrence of some chronic diseases associated with residual coagulant in treated wastewater. The use of alternative coagulants which are biodegradable and environmentally friendly could alleviate the problem associated with these diseases. This work investigates the capability of Jatropha curcas seed and presscake (the residue left after oil extraction) to reduce the turbidity of wastewater through coagulation. The coagulant was prepared by dissolving Jatropha curcas seed and presscake powder into solution. Then jar tests were conducted on kaolin solution as the model wastewater. The Jatropha seed was found to be an effective coagulant with more than 96% of turbidity removal at pH 1–3 and pH 11–12. The highest turbidity removal was recorded at pH 3 using a dosage of 120 mg/L. The flocs formed using Jatropha were observed to be bigger and to sediment faster when compared with flocs formed using alum. The turbidity removal was high (>98%) at all turbidities (100 NTU to 8000 NTU), suggesting its suitability for a wide range of industrial wastewater. The performance of Jatropha presscake after extraction of oil was also comparable to the fresh seed and alum at highly acidic and highly alkaline conditions. The addition of Jatropha did not significantly affect the pH of the kaolin samples after treatment and the sludge volume produced was less in comparison to alum. These results strongly support the use of Jatropha curcas seed and presscake as a potential coagulant agent.

Effect of storage of shelled Moringa oleifera seeds from reaping time on turbidity removal

Moringa oleifera is an indigenous plant to Malaysia whose seeds are used for water purification. Many studies on Moringa oleifera have shown that it is highly effective as a natural coagulant for turbidity removal. In this study, two different methods for extraction of Moringas active ingredient were investigated. Results of sodium chloride (NaCl) and distilled water extraction of Moringa oleifera seeds showed that salt solution extraction was more efficient than distilled water in extracting Moringas active coagulant ingredient. The optimum dosage of shelled Moringa oleifera seeds extracted by the NaCl solution was comparable with that of the conventional chemical coagulant alum. Moreover, the turbidity removal efficiency was investigated for shelled Moringa oleifera seeds before drying in the oven under different storage conditions (i.e. open and closed containers at room temperature, 27 °C) and durations (fresh, and storage for 2, 4, 6 and 8 weeks from the time the seeds were picked from the trees). Our results indicate that there are no significant differences in coagulation efficiencies and, accordingly, turbidity removals between the examined storage conditions and periods.

Optimal planning of biodiesel supply chain using a linear programming model

This paper pre sents a method for the improvement of economic performance of biofuel supply chain. A mathematical model is proposed for optimal planning of biofuel supply chain in order to minimize the total operational costs. The model is linear and takes into consideration the availability of feedstock and biorefineries and determines the optimal schedule for harvesting and transportation of biomass feedstocks, biodiesel production and distribution over the planning horizon. The model is applied to a case study for the production of biodiesel from palm oil and jatropha in Malaysia.

Multi-Objective Particle Swarm Optimization for Optimal Planning of Biodiesel Supply Chain in Malaysia

In this paper we develop a mathematical model for optimal planning of the biofuel supply chain. The model considers the optimal selection of feedstock while minimizing the total cost and social impact over the planning horizon. A multi-objective linear programming model (MOLP) is proposed to find the optimal solution. A multi-objective particle swarm optimization (MOPSO) method is applied to solve the mathematical model and it is compared with non-dominated sorting genetic algorithm (NSGA-II) . The model is used to evaluate the biodiesel production from palm oil and jatropha in Malaysia.