Treatment of sullage using activated cabon from consortium of selected agro-wastes
Date
2019
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Federal University of Technology, Owerri
Abstract
ABSTRACT
The study investigated the effectiveness of treating sullage using activated carbons from rice husk, corn cob and coconut husk. The agrowastes were sourced from Relief Market, Owerri while sullage samples were collected with 10 litre container from Federal University of Technology, Owerri (FUTO) students’ hostels. Agrowastes were carbonized at 600oC and chemically activated using phosphoric acid (H3PO4) before they were used as adsorbents. pH, Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD), nitrate (NO3 -), phosphate (PO4-), chloride (Cl-), sulphate (SO42-); heavy metals (mercury, Hg; cadmium, Cd; chromium, Cr and lead, Pb) ) and microbial load of the sullage samples were analyzed before and after treatment with biosorbents. Titrimetric, spectrophotometric, and cultural methods were used to determine the chemical, heavy metals concentrations and microbial load respectively. Percentage yield of activated carbon were 35.7% (rice), 22.0% (corncob) and 10% (coconut husk). Initial concentration of the chemical parameters of sullage samples showed COD to be 486.2±87 mg/l, BOD, 175.0±3.1 mg/l; pH, 7.33±0.1; Cl-, 31.0±5.5 mg/l; NO3 -, 28.6±24 ppm; PO4 - , 7.08±3.2 ppm and SO4 2- , 347.08±67.1 ppm. After treatments, COD ranged from 122.2±10 - 190.5±25 mg/l, BOD, 44.0±3.5 – 68.6.0±9.0 mg/l, pH, 7.08±0.1 - 7.18±0.1, Cl- , 17.28 - 21.13 mg/l, NO3 - , 0.0 - 12.79 ppm and sulphate 117.7 - 251.7 ppm. Initial values of heavy metals were: Hg 4.01±0.6 ppm, Cr, 0.13±0.3, Cd, 0.076±0.0 ppm and Pb, 0.06±0.0ppm. After treatments, Hg ranged from 1.60±0.5 - 2.51±0.3, Cr, 0.00; Cd, 0.0 – 0.008 ppm, Pb, 0.0 – 0.06 ppm. Before treatment, Total Heterotrophic Count (THC) was 1.2x1011 cfu/ml, Total Coliform Count (TCC), 6.4x106 cfu/ml and Total Fungi Count (TFC) 2.2x1010 cfu/ml. Staphylococcus sp, Micrococcus sp, Bacillus sp, Salmonella sp, Saccharomyces sp and Penicillium were present in the sullage. THC after the treatment ranged from 1.69x109 to 7.6x1010 cfu/ml; TCC, 2.2x105 - 7.3x108 cfu/ml and TFC 1.0x108 - 1.2x109 cfu/ml. There was significant difference (p≤0.05) between the untreated and the treated sullage samples. The efficiency of the individual adsorbents in reducing the chemical parameters was of this order: ricehusk > corncob > coconut husk. In combination it was, rice husk+corncob+coconuthusk > ricehusk +corncob > corncob+coconuthusk > ricehusk+coconuthusk. For heavy metals removal, efficiency of individual adsorbents was of the order: ricehusk > corncob > coconuthusk, while when combined, it was: ricehusk+corncob > corncob+coconuthusk > ricehusk+corncob+coconuthusk > rice husk+coconut husk. High percentage reduction observed of chemical properties, heavy metal levels; complete elimination of Bacillus sp and general reduction of the microbial load revealed that activated carbons from rice husk, corn cob and coconut husk can be used singly or combined for the purification of sullage.
Description
This thesis is for the award of Master of Science (M.Sc) in Biotechnology
Keywords
Activated carbon, agrowastes, carbonization, coconut husk, corn cob, rice husk, sullage, Department of Biotechnology
Citation
Nduka, C. A. (2019). Treatment of sullage Using Activated cabon from consortium of selected agro-wastes {Unpublished Master's Thesis), Federal University of Technology, Owerri, Nigeria