Application Of Banana Stem And Rice Straw Derived Bio-Flocculants For Textile Wastewater Treatment
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Date
2016-01
Authors
Ishak, Siti Aisyah
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
This study involve three different stages which are extraction of bio-flocculant
(P) from banana pseudo-stem and rice straw, treatment of textile wastewater treated
effluent using extracted bio-flocculant and phytotoxicity test on the sludge produced
after coagulation and flocculation process. The bio-flocculant extracted from banana
pseudo-stem using hot acid extraction process was found to be higher in yield at 32.8 %
while only 16.2% from rice straw was manage to collect from the dry weight 10 g
respectively. Later the bio-flocculant was analysing using Fourier Transform Infrared
Spectroscopy (FTIR) to detect the existence of functional group which helps in the
flocculation process. Hydroxyl and carboxyl group was detected from the FTIR
analysis. The textile wastewater treated effluent was analysed for colour and COD
reduction by coagulation (FeCl3) and flocculation (P and PAM) using a standard jar test
apparatus. The coagulation and flocculation process was run using Response Surface
Design – Central Composite Design in order to see the efficiency between (FeCl3 and P)
and (FeCl3and PAM) at the optimum condition with varied parameters such as pH,
coagulant dose and flocculant dose. Treatment by FeCl3 and PAM shows the highest
colour removal with 95% (31 pt. co) and 92.0 % (42 mg/ L) COD reduction at condition
pH around 5.4, 375 mg/ L of coagulant and 28 mg/ L of flocculant dose. While the
treatment with FeCl3 and P was able to remove the colour around 83.0 % (104 mg/ L)
and 76.0 % (127 mg/ L) of COD reduction at treatment conditions of pH 7.2, coagulant
dose 353.0 mg/ L, and flocculant dose 30.9 mg/L. Finally, the sludge residue from the process was analysed for phytotoxicity test using Lactuca sativa seeds. Based on the
seed germination test, the sludge produce after the process using bio-flocculant showed
less toxicity index (LC50: 55) rather than PAM (LC50: 19). In conclusion, the used of
bio-flocculant was a success in order to remove colour and COD of textile wastewater
treated effluent. Furthermore, the sludge produced also show a positive effect whilst is at
low toxicity index.
Description
Keywords
Banana pseudo-stem and rice straw