| Biography | |
|---|---|
 Prof. Hamidi Abdul Aziz Universiti Sains Malaysia, Malaysia |
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| Title: Coagulation and flocculation process in landfill leachate treatment: Treatment performance and toxicity evaluation | |
| Abstract: Leachate is highly polluted wastewater that may cause danger to the surface and groundwater if not treated well. An integrated treatment method is always necessary. A new wastewater treatment process involving coagulation and flocculation process was adapted in this study, involving Ferric Chloride (FeCl3) as the main coagulant, Chitosan and Aloe Vera as a coagulant aid. Leachate samples were collected from one of the local landfills in Malaysia and was treated for ammonia, colour, turbidity, suspended solids (SS) and chemical oxygen demand (COD) using standard jar test procedures. The influence of optimum dosages, pH, floc size and sludge properties were evaluated. A standard acute toxicity test was conducted on the treated effluent. The results indicated that the optimum pH and dosage for FeCl3 were at pH 6 and 3600 mg/L FeCl3 with 95.5%, 98.2%, 97.8%, and 51.9% removals for colour, SS, turbidity and COD, respectively, with poor removal for ammonia. Chitosan and Aloe vera was not efficient when used as a primary coagulant. When 4000 mg/L Chitosan was used as a coagulant aid in combination with FeCl3, it reduced the FeCl3 concentration, from 3600 mg/L to 2000 mg/L with 13.7%, 95.4%, 97.7%, 96.4% and 36.4% reductions of ammonia, colour, SS, turbidity and COD, respectively. These were comparable with FeCl3 when it was used alone. Aloe Vera as a coagulant aid (8,000 mg/L) removed 87.4%, 89.1%, 75.7% and 34.5% of colour, SS, turbidity, and COD respectively. However, the removal of ammonia was insignificant. Compared to Chitosan, Aloe vera was only able to marginally reduce the initial FeCl3 concentration from 3600 mg/L to 3000 mg/L. The optimum Aloe Vera concentration as a coagulant aid was 8000 mg/L. Chitosan as a coagulant aid had a higher sludge settling velocity (0.69 cm/min) with with bigger floc size (198.52 µm). It was found that the combination of 2000 mg/L FeCl3 with 4000 mg/L Chitosan gave better removals for all the pollutants compared to Aloe Vera as a coagulant aid. It reduced the dosage of the main coagulant (FeCl3), improving the sludge settling rate, at the same time, increasing the floc size. Acute toxicity test indicated that the treated effluent is safe for disposal. Keywords: Coagulation and flocculation; Aloe vera; chitosan; landfill; leachate, acute toxicity test | |
| Biography: Dr Hamidi Abdul Aziz is a Professor in Environmental Engineering in the School of Civil Engineering, Universiti Sains Malaysia. Professor Aziz received his PhD in civil engineering (environmental) from the University of Strathclyde in 1992. He is currently the Head of the Solid Waste Management Cluster (SWAM), Universiti Sains Malaysia. He has 29 years of teaching and research experiences in the field of environmental engineering, mainly related to solid waste management and landfill technology, water and wastewater treatment, leachate treatment, bioremediation and pollution control. He was involved in numerous research, consultancy works and industrial testing projects related to solid waste management, water and wastewater treatment, landfill leachate treatment, curriculum design, environmental impact assessment, environmental management planning, pollution control. Professor Aziz has also involved in international projects, especially in Saudi Arabia. To date, he has graduated 3 Post-docs, nearly 100 PhD and MSc students and has published over 200 ISI papers and a few books. He has become an editor and sits in editorial board members of a few international journals. Malaysia Academy of Sciences awarded him a Top Research Scientist of Malaysia in 2012. Prof Aziz’s output is available from Researcher ID: F-6836-2010, Scopus ID: 7005960760’ ORCHID ID:http://orcid.org/0000-0001-6287-0560. His current h-index is 43 and 6219 citations from 265 papers. | |
