Hibiscus rosa-sinensis leaf as coagulant in wastewater and leachate treatments

dc.contributor.author	Awang, Nik Azimatolakma
dc.date.accessioned	2015-05-27T01:50:31Z
dc.date.available	2015-05-27T01:50:31Z
dc.date.issued	2011
dc.description.abstract	Applications of natural macromolecular coagulants are having a bright future because of their abundant source, low price, multifunction and its biodegradibility as compared to conventional chemical-based coagulants. The use of extracts from Hibiscus rosasinensis leaves as coagulant has not been discussed in literature. This research determines water (HBaqs) and thioglycollic acid treated (HBpowd) extraction of carbohydrate coagulants from the leaves of Hibiscus rosa-sinensis. and examines its chemical characteristics (i.e. isoelectric point (IEP), molecular weight and Fourier Transform Infrared). Identified as polymers with high molecular weight, HBaqs (183 kDa) and HBpowd (1 08 kDa) act as anionic coagulants to promote bridging mechanism via main functional groups, carboxyl (C=O) and hydroxyl (OH). The ability of Hibiscus rosasinensis leaves extract to act as primary coagulant and coagulants aid in conjunction with alum was evaluated using the leachate collected from Pulau Burung Landfill Site (PBLS) as well as the domestic wastewater collected from oxidation pond of treatment plant in the Engineering Campus of Universiti Sains Malaysia. Leachate from PBLS could be classified as stabilized leachate by having a high concentraction of ammonia nitrogen (NH3-N) (2124 mg/L) and chemical oxygen demand (COD) (2736 mg/L). Whilst, parameters tested in domestic wastewater was generally under the limits set in Standard B, Environmental Quality Act 1974, Regulation 2009, Malaysia. Jar test results were analyzed based on the coagulation activity and the removal percentage of suspended solids (SS), turbidity, iron (Fe3+), NH3-N, COD and colour. In addition, operating conditions during coagulation, floc strength and sediment percentage properties were also studied. Results revealed that 20 mg/L HBaqs at pH 12 achieved the highest removal of all parameters in the domestic wastewater and managed to suppress alum with 74%, 98%, 35%, 59%, 87% and 92% of SS, Fe3 +, NH3-N, COD, turbidity and colour removal from its initial values of 38 mg/L, 1.68 mg!L, 8.75 mg!L, 203 mg/L, 63 F AU and 182 PtCo, respectively. In comparison, 20 mg/L alum at pH 6 had removed only 50%, 86%, 12%, 48%, 81% and 40% of SS, Fe3 +, NH3-N, COD, turbidity and colour, respectively. Generally, HBaqs and HBpowd showed low removal rates for all parameter tested in leachate as compared to 7000 mg/L alum at pH 6. However, at 2000 mg/L and pH 10, HBaqs gave highest removal for NH3-N and turbidity (54% and 76% with initial values of2188 mg/L and 303 FAU, respectively) as compared to alum (25% and 50% reductions, respectively). A 43% reduction in the concentration of alum from its optimal dosage with doses of HBaqs and HBpowd below 1000 mg/L exhibited a synergic effect on Fe3+ (initial value, 2.69 mg/L) removal and recovery factors (RF). The average removal of Fe3 + using 7000 and 4000 mg/L alum as sole coagulant was around 65% and increased to nearly 100% when 1000 mg/L polymer was mixed with 7000 mg/L alum and 500 mg/L polymer was mixed with 4000 mg/L alum. Besides, floes formed by 4000 mg/L alum mixed with 500 mg/L HBaqs also showed better ability to resist shear with the higher strength factor (SF) of 114 which was much higher than 87 for alum alone.	en_US
dc.identifier.uri	http://hdl.handle.net/123456789/763
dc.language.iso	en	en_US
dc.subject	Rosa-sinensis	en_US
dc.title	Hibiscus rosa-sinensis leaf as coagulant in wastewater and leachate treatments	en_US
dc.type	Thesis	en_US