title: Isolation, characterization and the potential use of starch from jackfruit seed wastes as a coagulant aid for treatment of turbid water.
abstract: Fruit wastes constituting up to half of total fruit weight represent a large pool of untapped resources for isolation of starch with diverse applications. In this work, the possibility of isolating starch from tropical fruit wastes and its extended application as a natural coagulant was elucidated. Amongst the 12 various parts of fruit wastes selected, only jackfruit seeds contained more than 50% of total starch content. Using alkaline extraction procedures, starch has been successfully isolated from local jackfruit seeds with a yield of approximately 18%. Bell-shaped starch granules were observed under SEM with a granule size ranging from 1.1 to 41.6 μm. Detailed starch characteristics were performed to provide a comparison between the isolated seed starch and also conventional starches. Among them, chemical properties such as the content of starch, amylose, amylopectin and the corresponding molecular weights are some of the key characteristics which governed their performance as natural coagulants. The potential use of isolated seed starch as an aid was then demonstrated in both suspensions of kaolin (model synthetic system) and Chlorella sp. microalga (real-time application) with plausible outcomes. At optimized starch dosage of 60 mg/L, the overall turbidity removal in kaolin was enhanced by at least 25% at a fixed alum dosage of 2.1 mg/L. Positive turbidity and COD removals were also observed in the treatment of Chlorella suspensions. Starches which served as bridging agents aided in the linkage of neighbouring microflocs and subsequently, forming macroflocs through a secondary coagulation mechanism: adsorption and bridging.
authors.affiliation: Chemical Engineering Discipline, School of Engineering, Monash University Malaysia, 47500, Bandar Sunway, Selangor, Malaysia.
authors.forename: Sook Yan
authors.initials: SY
authors.lastname: Choy
authors.affiliation: Chemical Engineering Discipline, School of Engineering, Monash University Malaysia, 47500, Bandar Sunway, Selangor, Malaysia.
authors.forename: Krishna Murthy Nagendra
authors.initials: KM
authors.lastname: Prasad
authors.affiliation: Chemical Engineering Discipline, School of Engineering, Monash University Malaysia, 47500, Bandar Sunway, Selangor, Malaysia.
authors.forename: Ta Yeong
authors.initials: TY
authors.lastname: Wu
authors.affiliation: Civil Engineering Discipline, School of Engineering, Monash University Malaysia, 47500, Bandar Sunway, Selangor, Malaysia.
authors.forename: Mavinakere Eshwaraiah
authors.initials: ME
authors.lastname: Raghunandan
authors.affiliation: Key Laboratory of Plant Resources Conservation and Sustainable Utilization, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China.
authors.forename: Bao
authors.initials: B
authors.lastname: Yang
authors.affiliation: Institute of Ocean and Earth Sciences & Institute of Biological Sciences, University of Malaya, 50603, Kuala Lumpur, Malaysia.
authors.forename: Siew-Moi
authors.initials: SM
authors.lastname: Phang
authors.affiliation: Chemical Engineering Discipline, School of Engineering, Monash University Malaysia, 47500, Bandar Sunway, Selangor, Malaysia. ramanan@monash.edu.|Advanced Engineering Platform, School of Engineering, Monash University Malaysia, 47500, Bandar Sunway, Selangor, Malaysia. ramanan@monash.edu.
authors.forename: Ramakrishnan Nagasundara
authors.initials: RN
authors.lastname: Ramanan
mesh_terms: D000687:Amylopectin; D000688:Amylose; D031622:Artocarpus; D002708:Chlorella; D008970:Molecular Weight; D012639:Seeds / Q000737:chemistry; D013213:Starch; D014867:Water / Q000032:analysis; D018508:Water Purification / Q000379:methods*
chemical_list: D014867:Water; D013213:Starch; D000688:Amylose; D000687:Amylopectin
keywords: Amylopectin; Bridging mechanism; Coagulant aid; Jackfruit seeds; Microalgae harvesting; Starch properties