Preliminary Study on Extraction of Bio-flocculants from Okra and Chinese Yam

Natural bio-flocculants were extracted from okra and Chinese yam using water extraction method, and the extract yield and their flocculating abilities were evaluated. Results showed that extraction of okra with seed removal and incubation followed by freeze drying enhanced the extract yield by 91% and improved the flocculating ability greatly by achieving solids removal of above 99% when compared with extraction without incubation and followed by oven drying. The effect of an incubation step was further investigated by using Chinese yam. With incubation, a higher extract yield of 2.95% was obtained compared with the extraction without incubation at 2.13% and high flocculating ability was achieved at 99.5% solids removal. To further investigate the application of bio-flocculants, the samples with the highest extract yield and flocculating ability were selected for a case study focusing on treatment of oleochemical wastewater. Yam bio-flocculant showed its flocculating activity with 80% solids removal when it was coupled with coagulant without pH alteration. However, pH adjustment was required for okra bio-flocculant. In conclusion, highly efficient okra and yam bio-flocculants were successfully extracted and their applicability to wastewater treatment was proven.

[1]  L. Craker,et al.  Effects of drying methods on qualitative and quantitative properties of essential oil of two basil landraces. , 2013, Food chemistry.

[2]  H. Liimatainen,et al.  Coagulation–flocculation treatment of municipal wastewater based on anionized nanocelluloses , 2013 .

[3]  V. Samavati.  Polysaccharide extraction from Abelmoschus esculentus: optimization by response surface methodology. , 2013, Carbohydrate polymers.

[4]  Aimin Li,et al.  Flocculation performance and mechanism of graphene oxide for removal of various contaminants from water. , 2013, Water research.

[5]  Hanqing Yu,et al.  Synthesis, characterization and application of a novel starch-based flocculant with high flocculation and dewatering properties. , 2013, Water research.

[6]  S. A. H. Goli,et al.  Evaluation of six drying treatments with respect to essential oil yield, composition and color characteristics of Thymys daenensis subsp. daenensis. Celak leaves , 2013 .

[7]  Khai Ern Lee,et al.  Development, characterization and the application of hybrid materials in coagulation/flocculation of wastewater: A review , 2012 .

[8]  Bahareh Tabatabaee Amid,et al.  Optimisation of aqueous extraction of gum from durian (Durio zibethinus) seed: A potential, low cost source of hydrocolloid. , 2012, Food chemistry.

[9]  M. F. Chong,et al.  Direct Flocculation Process for Wastewater Treatment , 2012 .

[10]  Aimin Li,et al.  Evaluation of the flocculation performance of carboxymethyl chitosan-graft-polyacrylamide, a novel amphoteric chemically bonded composite flocculant. , 2012, Water research.

[11]  M. Yusoff,et al.  Application of psyllium husk as coagulant and coagulant aid in semi-aerobic landfill leachate treatment. , 2011, Journal of hazardous materials.

[12]  D. Pasternak,et al.  Okra (Abelmoschus spp.) in West and Central Africa: Potential and progress on its improvement , 2010 .

[13]  K. Ameena,et al.  Isolation of the mucilages from Hibiscus rosasinensis linn. and Okra (Abelmoschus esculentus linn.) and studies of the binding effects of the mucilages , 2010 .

[14]  Evan Diamadopoulos,et al.  Flocculation behavior of mallow and okra mucilage in treating wastewater , 2009 .

[15]  François Renault,et al.  Chitosan for coagulation/flocculation processes. An eco-friendly approach. , 2009 .

[16]  T. Durance,et al.  Compressive characteristics of cellular solids produced using vacuum-microwave, freeze, vacuum and hot air dehydration methods , 2009 .

[17]  Abdul Latif Ahmad,et al.  Improvement of alum and PACl coagulation by polyacrylamides (PAMs) for the treatment of pulp and paper mill wastewater , 2008 .

[18]  J.G.M. van der Lubbe,et al.  Handbook Biological Waste Water Treatment:Design and Optimisation of Activated sludge Systems , 2007 .

[19]  A. Mishra,et al.  The flocculation performance of Tamarindus mucilage in relation to removal of vat and direct dyes. , 2006, Bioresource technology.

[20]  A. Mishra,et al.  Flocculation behaviour of model textile wastewater treated with a food grade polysaccharide. , 2005, Journal of hazardous materials.

[21]  Anurag Yadav,et al.  Fenugreek mucilage for solid removal from tannery effluent , 2004 .

[22]  Monika Agarwal,et al.  Fenugreek mucilage as a flocculating agent for sewage treatment , 2003 .

[23]  Rajani Srinivasan,et al.  Flocculation of textile wastewater by Plantago psyllium mucilage , 2002 .

[24]  R. Mishra,et al.  Plantago Psyllium Mucilage For Sewage and Tannery Effluent Treatment , 2002 .

[25]  Cristina Ratti,et al.  Hot air and freeze-drying of high-value foods : a review , 2001 .

[26]  Awwa,et al.  Standard Methods for the examination of water and wastewater , 1999 .