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Leong KY, Adnan R, Lim PE, Ng SL, Seng CE. Effect of operational factors on bioregeneration of binary phenol and 4-chlorophenol-loaded granular activated carbon using PVA-immobilized biomass cryogels. Environ Sci Pollut Res Int 2017; 24:20959-20971. [PMID: 28726220 DOI: 10.1007/s11356-017-9636-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Accepted: 06/26/2017] [Indexed: 06/07/2023]
Abstract
The effects of dry biomass density in cryogel beads, shaking speed and initial concentration ratio of phenol to 4-chlorophenol (4-CP) on the bioregeneration efficiencies of binary phenol and 4-CP-loaded granular activated carbon (GAC) for phenol and 4-CP, respectively, were investigated under the simultaneous adsorption and biodegradation approach. The results revealed higher bioregeneration efficiencies of binary-loaded GAC for phenol and 4-CP at higher dry biomass density but moderate shaking speed. The optimum dry biomass density in cryogel beads and shaking speed for use in bioregeneration were found to be 0.01 g/mL and 250 rpm, respectively. With respect to the initial phenol to 4-CP concentration ratio, the bioregeneration efficiencies were lower under increasing phenol and 4-CP initial concentrations, respectively, with the effect being more conspicuous under increasing 4-CP concentration. Higher bioregeneration efficiencies were achieved with the use of immobilized rather than suspended biomasses.
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Affiliation(s)
- Kwok-Yii Leong
- School of Chemical Sciences, Universiti Sains Malaysia, 11800, Penang, Malaysia
- Centre for Water Research, Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Dr. 2, Singapore, 117576, Singapore
| | - Rohana Adnan
- School of Chemical Sciences, Universiti Sains Malaysia, 11800, Penang, Malaysia.
| | - Poh-Eng Lim
- School of Chemical Sciences, Universiti Sains Malaysia, 11800, Penang, Malaysia
| | - Si-Ling Ng
- School of Chemical Sciences, Universiti Sains Malaysia, 11800, Penang, Malaysia
| | - Chye-Eng Seng
- School of Chemical Sciences, Universiti Sains Malaysia, 11800, Penang, Malaysia
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2
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Kew SL, Adnan R, Lim PE, Seng CE. Bioregeneration of cresol-loaded granular activated carbon using immobilized biomass: Effects of operational factors and chemical structure of cresol isomers. J Taiwan Inst Chem Eng 2016. [DOI: 10.1016/j.jtice.2016.03.039] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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3
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Tee HC, Lim PE, Seng CE, Mohd Nawi MA, Adnan R. Enhancement of azo dye Acid Orange 7 removal in newly developed horizontal subsurface-flow constructed wetland. J Environ Manage 2015; 147:349-355. [PMID: 25284799 DOI: 10.1016/j.jenvman.2014.09.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Revised: 09/09/2014] [Accepted: 09/16/2014] [Indexed: 06/03/2023]
Abstract
Horizontal subsurface-flow (HSF) constructed wetland incorporating baffles was developed to facilitate upflow and downflow conditions so that the treatment of pollutants could be achieved under multiple aerobic, anoxic and anaerobic conditions sequentially in the same wetland bed. The performances of the baffled and conventional HSF constructed wetlands, planted and unplanted, in the removal of azo dye Acid Orange 7 (AO7) were compared at the hydraulic retention times (HRT) of 5, 3 and 2 days when treating domestic wastewater spiked with AO7 concentration of 300 mg/L. The planted baffled unit was found to achieve 100%, 83% and 69% AO7 removal against 73%, 46% and 30% for the conventional unit at HRT of 5, 3 and 2 days, respectively. Longer flow path provided by baffled wetland units allowed more contact of the wastewater with the rhizomes, microbes and micro-aerobic zones resulting in relatively higher oxidation reduction potential (ORP) and enhanced performance as kinetic studies revealed faster AO7 biodegradation rate under aerobic condition. In addition, complete mineralization of AO7 was achieved in planted baffled wetland unit due to the availability of a combination of aerobic, anoxic and anaerobic conditions.
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Affiliation(s)
- Heng-Chong Tee
- School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - Poh-Eng Lim
- School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia.
| | - Chye-Eng Seng
- School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - Mohd Asri Mohd Nawi
- School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - Rohana Adnan
- School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
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4
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Al-Amrani WA, Lim PE, Seng CE, Wan Ngah WS. Factors affecting bio-decolorization of azo dyes and COD removal in anoxic–aerobic REACT operated sequencing batch reactor. J Taiwan Inst Chem Eng 2014. [DOI: 10.1016/j.jtice.2013.06.032] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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5
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Lim JW, Lim PE, Seng CE, Adnan R. Alternative solid carbon source from dried attached-growth biomass for nitrogen removal enhancement in intermittently aerated moving bed sequencing batch reactor. Environ Sci Pollut Res Int 2014; 21:485-494. [PMID: 23807562 DOI: 10.1007/s11356-013-1933-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 06/11/2013] [Indexed: 06/02/2023]
Abstract
The feasibility of using dried attached-growth biomass from the polyurethane (PU) foam cubes as a solid carbon source to enhance the denitrification process in the intermittently aerated moving bed sequencing batch reactor (IA-MBSBR) during the treatment of low COD/N containing wastewater was investigated. By packing the IA-MBSBR with 8% (v/v) of 8-mL PU foam cubes saturated with dried attached-growth biomass, total nitrogen removal efficiency of 80% could be achieved for 10 consecutive cycles of operation when the intermittent aeration strategy of consecutive 1 h of aeration followed by 2 h of non-aeration period during the REACT period of the IA-MBSBR was adopted. Negligible release of ammonium nitrogen (NH4(+)-N) and slow-release of COD from the dried biomass would ensure that the use of this solid carbon source would not further burden the treatment system. The slow-releasing COD was found to have no effect in promoting the assimilation process and would also allow the carbon source to be used for many cycles of operation. The 'carbon-spent' PU foam cubes could be reused by merely drying at 60 °C at the end of the operational mode. Thus, the dried attached-growth biomass formed on the PU foam cubes could be exploited as an alternative solid carbon source for the enhancement of denitrification process in the IA-MBSBR.
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Affiliation(s)
- Jun-Wei Lim
- School of Chemical Sciences, Universiti Sains Malaysia, 11800, Penang, Malaysia
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6
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Al-Amrani WA, Lim PE, Seng CE, Wan Ngah WS. Effects of co-substrate and biomass acclimation concentration on the bioregeneration of azo dye-loaded mono-amine modified silica. Bioresour Technol 2013; 143:584-591. [PMID: 23835263 DOI: 10.1016/j.biortech.2013.06.055] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 06/12/2013] [Accepted: 06/14/2013] [Indexed: 06/02/2023]
Abstract
Bioregeneration of mono-amine modified silica gel (MAMS) adsorbent loaded with Acid Orange 7 (AO7), Acid Yellow 9 (AY9) and Acid Red 14 (AR14), respectively, was investigated under two different operational conditions, namely absence/presence of sucrose/bacto-peptone as the co-substrate and different biomass acclimation concentrations. The results revealed that the AY9- and AR14-loaded MAMS adsorbents could almost be completely bioregenerated but only in the presence of co-substrate whereas the bioregeneration of AO7-loaded MAMS could achieve up to 71% in the absence of the co-substrate. These differences could be related to the structural properties of the investigated azo dyes. In addition, the results showed that the bioregeneration duration of AO7-loaded MAMS could be progressively shortened by using biomass acclimated to increasingly higher AO7 concentration. However, the bioregeneration efficiencies were found to be relatively unchanged under different biomass acclimation concentrations.
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Affiliation(s)
- Waheeba A Al-Amrani
- School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia.
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7
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Toh RH, Lim PE, Seng CE, Adnan R. Immobilized acclimated biomass-powdered activated carbon for the bioregeneration of granular activated carbon loaded with phenol and o-cresol. Bioresour Technol 2013; 143:265-274. [PMID: 23796608 DOI: 10.1016/j.biortech.2013.05.126] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 05/30/2013] [Accepted: 05/31/2013] [Indexed: 06/02/2023]
Abstract
The objectives of the study are to use immobilized acclimated biomass and immobilized biomass-powdered activated carbon (PAC) as a novel approach in the bioregeneration of granular activated carbon (GAC) loaded with phenol and o-cresol, respectively, and to compare the efficiency and rate of the bioregeneration of the phenolic compound-loaded GAC using immobilized and suspended biomasses under varying GAC dosages. Bioregeneration of GAC loaded with phenol and o-cresol, respectively, was conducted in batch system using the sequential adsorption and biodegradation approach. The results showed that the bioregeneration efficiency of GAC loaded with phenol or o-cresol was basically the same irrespective of whether the immobilized or suspended biomass was used. Nonetheless, the duration for bioregeneration was longer under immobilized biomass. The beneficial effect of immobilized PAC-biomass for bioregeneration is the enhancement of the removal rate of the phenolic compounds via adsorption and the shortening of the bioregeneration duration.
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Affiliation(s)
- Run-Hong Toh
- School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
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8
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Lim JW, Lim PE, Seng CE, Adnan R. Simultaneous 4-chlorophenol and nitrogen removal in moving bed sequencing batch reactors packed with polyurethane foam cubes of various sizes. Bioresour Technol 2013; 129:485-494. [PMID: 23266850 DOI: 10.1016/j.biortech.2012.11.111] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Revised: 11/19/2012] [Accepted: 11/25/2012] [Indexed: 06/01/2023]
Abstract
Moving bed sequencing batch reactors (MBSBRs) packed with 8% (v/v) of 8-, 27- and 64-mL polyurethane (PU) foam cubes, respectively, were investigated for simultaneous 4-chlorophenol (4-CP) and nitrogen removal at increasing 4-CP concentration. When the 4-CP concentration exceeded 300 mg L(-1), the MBSBR with 27-mL foam cubes was observed to outperform the other MBSBRs in removing 4-CP and nitrogen. The reasons were: (1) there were more biomass in inner layer of the 27-mL cubes, compared to that of the 8-mL cubes, which was more shielded from the inhibitory effect of 4-CP and (2) the 27-mL cubes were more mobile than the 64-mL cubes. Although increasing 4-CP concentration to 600 mg L(-1) resulted in incomplete removal of 4-CP in the MBSBRs, results of the batch reactor with 27-mL foam cubes showed that complete 4-CP removal within the REACT period could be achieved by increasing the packing volume to 20%.
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Affiliation(s)
- Jun-Wei Lim
- School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
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9
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Al-Amrani WA, Lim PE, Seng CE, Ngah WSW. Operational factors affecting the bioregeneration of mono-amine modified silica loaded with Acid Orange 7. Water Res 2012; 46:6419-6429. [PMID: 23062787 DOI: 10.1016/j.watres.2012.09.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 08/26/2012] [Accepted: 09/06/2012] [Indexed: 06/01/2023]
Abstract
In this study, the operational factors affecting the bioregeneration of AO7-loaded MAMS particles in batch system, namely redox condition, initial acclimated biomass concentration, shaking speed and type of acclimated biomass were investigated. The results revealed that with the use of mixed culture acclimated to AO7 under anoxic/aerobic conditions, enhancement of the bioregeneration efficiency of AO7-loaded MAMS and the total removal efficiency of COD could be achieved when the bio-decolorization and bio-mineralization stages were fully aerated with dissolved oxygen above 7 mg/L. Shorter duration of bioregeneration was achieved by using relatively higher initial biomass concentration and lower shaking speed, respectively, whereas variations of biomass concentration and shaking speed did not have a pronounced effect on the bioregeneration efficiency. The duration and efficiency of bioregeneration process were greatly affected by the chemical structures of mono-azo dyes to which the biomasses were acclimated.
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10
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Al-Amrani WA, Lim PE, Seng CE, Ngah WSW. Bioregeneration of mono-amine modified silica and granular activated carbon loaded with Acid Orange 7 in batch system. Bioresour Technol 2012; 118:633-637. [PMID: 22704829 DOI: 10.1016/j.biortech.2012.05.090] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 05/16/2012] [Accepted: 05/19/2012] [Indexed: 06/01/2023]
Abstract
The objectives of this study were: (1) to investigate the role of mixed culture of biomass in the regeneration of mono-amine modified silica (MAMS) and granular activated carbon (GAC) loaded with Acid Orange 7 (AO7), (2) to quantify and compare the bioregeneration efficiencies of AO7-loaded MAMS and GAC using the sequential adsorption and biodegradation approach and (3) to evaluate the reusability of bioregenerated MAMS. The results show that considerably higher bioregeneration efficiency of AO7-loaded MAMS as compared to that of AO7-loaded GAC was achieved due to higher reversibility of adsorption of MAMS for AO7 and favorable pH factor resulting in more AO7 desorption. The progressive loss of adsorption capacity of MAMS for AO7 with multiple cycles of use suggests possible chemical and microbial fouling of the adsorption sites.
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11
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Oh WD, Lim PE, Seng CE, Sujari ANA. Kinetic modeling of bioregeneration of chlorophenol-loaded granular activated carbon in simultaneous adsorption and biodegradation processes. Bioresour Technol 2012; 114:179-187. [PMID: 22503192 DOI: 10.1016/j.biortech.2012.03.065] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 03/12/2012] [Accepted: 03/13/2012] [Indexed: 05/31/2023]
Abstract
A kinetic model incorporating adsorption, desorption and biodegradation processes was developed to describe the bioregeneration of granular activated carbon (GAC) loaded with 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-DCP), respectively, in simultaneous adsorption and biodegradation processes. The model was numerically solved and the results showed that the kinetic model was well-fitted (R(2)>0.83) to the experimental data at different GAC dosages and at various initial 4-CP and 2,4-DCP concentrations. The rate of bioregeneration in simultaneous adsorption and biodegradation processes was influenced by the ratio of initial chlorophenol concentration to GAC dosage. Enhancement in the rate of bioregeneration was achieved by using the lowest ratio under either one of the following experimental conditions: (1) increasing initial chlorophenol concentration at constant GAC dosage and (2) increasing GAC dosage at constant initial chlorophenol concentration. It was found that the rate enhancement was more pronounced under the second experimental condition.
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Affiliation(s)
- Wen-Da Oh
- School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
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12
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13
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Tee HC, Lim PE, Seng CE, Nawi MAM. Newly developed baffled subsurface-flow constructed wetland for the enhancement of nitrogen removal. Bioresour Technol 2012; 104:235-242. [PMID: 22130081 DOI: 10.1016/j.biortech.2011.11.032] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Accepted: 11/07/2011] [Indexed: 05/31/2023]
Abstract
The objectives of this study are to compare the performance of newly developed baffled and conventional horizontal subsurface-flow (HSF) constructed wetlands in the removal of nitrogen at the hydraulic retention times (HRT) of 2, 3 and 5 days and to evaluate the potential of rice husk as wetland media for wastewater treatment. The results show that the planted baffled unit achieved 74%, 84% and 99% ammonia nitrogen (NH(4)(+)-N) removal versus 55%, 70% and 96% for the conventional unit at HRT of 2, 3 and 5 days, respectively. The better performance of the baffled unit was explained by the longer pathway due to the up-flow and down-flow conditions sequentially thus allowing more contact of the wastewater with the rhizomes and micro-aerobic zones. Near complete total oxidized nitrogen was observed due to the use of rice husk as wetland media which provided the COD as the electron donor in the denitrification process.
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Affiliation(s)
- Heng-Chong Tee
- School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
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14
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Khor SM, Ng SL, Lim PE, Seng CE. The effects of nickel(II) and chromium(VI) on oxygen demand, nitrogen and metal removal in a sequencing batch reactor. Environ Technol 2011; 33:1903-1914. [PMID: 22439579 DOI: 10.1080/09593330.2011.568008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The objective of this study was to evaluate the effects ofNi(II) and Cr(VI) individually and in combination on the simultaneous removal of chemical oxygen demand (COD), nitrogen and metals under a sequencing batch reactor (SBR) operation. Three identical laboratory-scale SBRs were operated with FILL, REACT, SETTLE, DRAW and IDLE periods in a ratio of 1:12:1:2:8 for a cycle time of 24 h until the steady state was achieved. Nickel(II) at increasing concentrations up to 35 mg/L was added to one of the reactors; Cr(VI) at increasing concentrations up to 25 mg/L was added to a second reactor; while a combination of Ni(II) and Cr(VI) in equal concentrations up to 10 mg/L was added to a third reactor. The results demonstrate that both Ni(II) and Cr(VI) exerted a more pronounced inhibitory effect on the removal of ammonia nitrogen (AN) than on COD removal. Synergistic and antagonistic inhibitory effects on the rates of COD and AN removal, respectively, were observed for the 50% Ni(II) and 50% Cr(VI) (w/w) mixture in the concentration range between 10 and 20 mg/L. The simultaneous presence of 50% Ni(II) and 50% Cr(VI) at a concentration of 20 mg/L resulted in system failure.
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Affiliation(s)
- S M Khor
- School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
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15
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Lim JW, Seng CE, Lim PE, Ng SL, Sujari ANA. Nitrogen removal in moving bed sequencing batch reactor using polyurethane foam cubes of various sizes as carrier materials. Bioresour Technol 2011; 102:9876-9883. [PMID: 21890353 DOI: 10.1016/j.biortech.2011.08.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 07/29/2011] [Accepted: 08/02/2011] [Indexed: 05/31/2023]
Abstract
The performance of moving bed sequencing batch reactors (MBSBRs) added with 8 % (v/v) of polyurethane (PU) foam cubes as carrier media in nitrogen removal was investigated in treating low COD/N wastewater. The results indicate that MBSBR with 8-mL cubes achieved the highest total nitrogen (TN) removal efficiency of 37% during the aeration period, followed by 31%, 24% and 19 % for MBSBRs with 27-, 64- and 125-mL cubes, respectively. The increased TN removal in MBSBRs was mainly due to simultaneous nitrification and denitrification (SND) process which was verified by batch studies. The relatively lower TN removal in MBSBR with larger PU foam cubes was attributed to the observation that larger PU foam cubes were not fully attached by biomass. Higher concentrations of 8-mL PU foam cubes in batch reactors yielded higher TN removal.
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Affiliation(s)
- Jun-Wei Lim
- School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
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16
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Oh WD, Lim PE, Seng CE, Sujari ANA. Bioregeneration of granular activated carbon in simultaneous adsorption and biodegradation of chlorophenols. Bioresour Technol 2011; 102:9497-9502. [PMID: 21871793 DOI: 10.1016/j.biortech.2011.07.107] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Revised: 07/27/2011] [Accepted: 07/28/2011] [Indexed: 05/31/2023]
Abstract
The objectives of this study are to obtain the time courses of the amount of chlorophenol adsorbed onto granular activated carbon (GAC) in the simultaneous adsorption and biodegradation processes involving 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-DCP), respectively, and to quantify the bioregeneration efficiency of GAC loaded with 4-CP and 2,4-DCP by direct measurement of the amount of chlorophenol adsorbed onto GAC. Under abiotic and biotic conditions, the time courses of the amount of chlorophenol adsorbed onto GAC at various GAC dosages for the initial 4-CP and 2,4-DCP concentrations below and above the biomass acclimated concentrations of 300 and 150 mg/L, respectively, were determined. The results show that the highest bioregeneration efficiency was achieved provided that the initial adsorbate concentration was lower than the acclimated concentration. When the initial adsorbate concentration was higher than the acclimated concentration, the highest bioregeneration efficiency was achieved if excess adsorbent was used.
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Affiliation(s)
- Wen-Da Oh
- School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
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17
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Abstract
The objective of this research was to evaluate the treatment ofp-nitrophenol (PNP) as a sole organic carbon source using a sequencing batch reactor (SBR) with the addition of adsorbent. Two types of adsorbents, namely powdered activated carbon (PAC) and pyrolysed rice husk (PRH) were used in this study. Two identical SBRs, each with a working volume of 10 L, were operated with fill, react, settle, draw and idle periods in the ratio of 2:8:1:0.75:0.25 for a cycle time of 12 h. The results showed that, without the addition of adsorbent, increasing the influent PNP concentration to 200 mg/L resulted in the deterioration of chemical oxygen demand (COD) removal efficiency and PNP removal efficiency in the SBRs. Improvement in the performance of the SBR was observed with the addition of PAC. When the dosage of 1.0 g PAC/cycle was applied, COD removal of 95% and almost complete removal of PNP were achieved at the influent PNP concentration of 300 mg/L. The kinetic study showed that the rates of COD and PNP removal can be described by the first-order kinetics. The enhancement of performance in the PAC-supplemented SBR was postulated to be due to the initial adsorption of PNP by the freshly added and the bioregenerated PAC, thus reducing the inhibition on the microorganisms. The PRH was found to be ineffective because of its relatively low adsorption capacity for PNP, compared with that of PAC.
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Affiliation(s)
- Y M Loo
- School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
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18
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Ng SL, Seng CE, Lim PE. Bioregeneration of activated carbon and activated rice husk loaded with phenolic compounds: Kinetic modeling. Chemosphere 2010; 78:510-516. [PMID: 20035966 DOI: 10.1016/j.chemosphere.2009.11.041] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Revised: 11/26/2009] [Accepted: 11/26/2009] [Indexed: 05/28/2023]
Abstract
A kinetic model consisting of first-order desorption and biodegradation processes was developed to describe the bioregeneration of phenol- and p-nitrophenol-loaded powdered activated carbon (PAC) and pyrolyzed rice husk (PRH), respectively. Different dosages of PAC and PRH were loaded with phenol or p-nitrophenol by contacting with the respective phenolic compound at various concentrations. The kinetic model was used to fit the phenol or p-nitrophenol concentration data in the bulk solution during the bioregeneration process to determine the rate constants of desorption, k(d), and biodegradation, k. The results showed that the kinetic model fitted relatively well (R(2)>0.9) to the experimental data for the phenol- and p-nitrophenol-loaded PAC as well as p-nitrophenol-loaded PRH. Comparison of the values of k(d) and k shows that k is much greater than k(d). This indicates clearly that the desorption process is the rate-determining step in bioregeneration and k(d) can be used to characterize the rate of bioregeneration. The trend of the variation of the k(d) values with the dosages of PAC or PRH used suggests that higher rate of bioregeneration can be achieved under non-excess adsorbent dosage condition.
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Affiliation(s)
- S L Ng
- Universiti Sains Malaysia, Penang, Malaysia
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19
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Goh CP, Seng CE, Sujari ANA, Lim PE. Performance of sequencing batch biofilm and sequencing batch reactors in simultaneous p-nitrophenol and nitrogen removal. Environ Technol 2009; 30:725-736. [PMID: 19705610 DOI: 10.1080/09593330902911689] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The objective of this study is to evaluate the performance of sequencing batch biofilm reactors (SBBRs) and sequencing batch reactor (SBR) in the simultaneous removal of p-nitrophenol (PNP) and ammoniacal nitrogen. SBBRs involved the use of polyurethane sponge cubes and polyethylene rings, respectively, as carrier materials. The results demonstrate that complete removal of PNP was achievable for the SBR and SBBRs up to the PNP concentration of 350 mg/l (loading rate of 0.368 kg/m3 d). At this loading rate, the average ammoniacal nitrogen removal efficiency for the SBR and SBBR (with polyethylene rings) was reduced to 86% and 96%, respectively. However, the SBBR (with polyurethane sponge cubes) still managed to achieve an almost 100% ammoniacal nitrogen removal. Based on the results, the performance of the SBBRs was better than that of SBR in PNP and ammoniacal nitrogen removal. The results of the gas chromatography mass spectroscopy, high-performance liquid chromatography and ultraviolet-visible analyses indicate that complete mineralization of PNP was achieved in all of the reactors.
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Affiliation(s)
- Chin-Ping Goh
- School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
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Ng SL, Seng CE, Lim PE. Quantification of bioregeneration of activated carbon and activated rice husk loaded with phenolic compounds. Chemosphere 2009; 75:1392-400. [PMID: 19307013 DOI: 10.1016/j.chemosphere.2009.02.049] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2008] [Revised: 02/20/2009] [Accepted: 02/20/2009] [Indexed: 05/23/2023]
Abstract
The bioregeneration efficiencies of powdered activated carbon (PAC) and pyrolyzed rice husk loaded with phenol and p-nitrophenol were quantified by oxygen uptake measurements using the respirometry technique in two approaches: (i) simultaneous adsorption and biodegradation and (ii) sequential adsorption and biodegradation. It was found that the applicability of the simultaneous adsorption and biodegradation approach was constrained by the requirement of adsorption preceding biodegradation in order to determine the initial adsorbent loading accurately. The sequential adsorption and biodegradation approach provides a good estimate of the upper limit of the bioregeneration efficiency for the loaded adsorbent in the simultaneous adsorption and biodegradation processes. The results showed that the mean bioregeneration efficiencies for PAC loaded with phenol and p-nitrophenol, respectively, obtained using the two approaches were in good agreement.
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Affiliation(s)
- S L Ng
- School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
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Tee HC, Seng CE, Noor AM, Lim PE. Performance comparison of constructed wetlands with gravel- and rice husk-based media for phenol and nitrogen removal. Sci Total Environ 2009; 407:3563-3571. [PMID: 19272632 DOI: 10.1016/j.scitotenv.2009.02.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2008] [Revised: 01/31/2009] [Accepted: 02/06/2009] [Indexed: 05/27/2023]
Abstract
This study aims to compare the performance of planted and unplanted constructed wetlands with gravel- and raw rice husk-based media for phenol and nitrogen removal. Four laboratory-scale horizontal subsurface-flow constructed wetland units, two of which planted with cattail (Typha latifolia) were operated outdoors. The units were operated at a nominal hydraulic retention time of 7 days and fed with domestic wastewater spiked with phenol concentration at 300 mg/L for 74 days and then at 500 mg/L for 198 days. The results show that planted wetland units performed better than the unplanted ones in the removal and mineralization of phenol. This was explained by the creation of more micro-aerobic zones in the root zone of the wetland plants which allow a faster rate of phenol biodegradation, and the phenol uptake by plants. The better performance of the rice husk-based planted wetland compared to that of the gravel-based planted wetland in phenol removal could be explained by the observation that more rhizomes were established in the rice husk-based wetland unit thus creating more micro-aerobic zones for phenol degradation. The role of rice husk as an adsorbent in phenol removal was considered not of importance.
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Affiliation(s)
- H C Tee
- School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
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Ong SA, Lim PE, Seng CE. Heavy metals and adsorbents effects on activated sludge microorganisms. Ann Chim 2004; 94:85-92. [PMID: 15141467 DOI: 10.1002/adic.200490007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
The sorption of Cu(II) and Cd(II) from synthetic solution by powdered activated carbon (PAC), biomass, rice husk (RH) and activated rice husk (ARH) were investigate under batch conditions. After activated by concentrated nitric acid for 15 hours at 60-65 degrees C, the adsorption capacity for RH was increased. The adsorbents arranged in the increasing order of adsorption capacities to the Langmuir Q degree parameter were biomass > PAC > ARH > RH. The addition of adsorbents in base mix solution had increased the specific oxygen uptake rate (SOUR) activated sludge microorganisms with and without the presence of metals. The increased of SOUR were due to the ability of PAC and RH in reducing the inhibitory effect of metals on microorganisms and provide a reaction site between activated sludge microorganisms and substrates.
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Affiliation(s)
- S A Ong
- School of Chemical Science, Universiti Sains Malaysia, Penang 11800, Malaysia.
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Ong SA, Lim PE, Seng CE. Effects of adsorbents and copper(II) on activated sludge microorganisms and sequencing batch reactor treatment process. J Hazard Mater 2003; 103:263-277. [PMID: 14573344 DOI: 10.1016/j.jhazmat.2003.07.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Wastewater treatment systems employing simultaneous adsorption and biodegradation processes have proven to be effective in treating toxic pollutants present in industrial wastewater. The objective of this study is to evaluate the effect of Cu(II) and the efficacy of the powdered activated carbon (PAC) and activated rice husk (ARH) in reducing the toxic effect of Cu(II) on the activated sludge microorganisms. The ARH was prepared by treatment with concentrated nitric acid for 15 h at 60-65 degrees C. The sequencing batch reactor (SBR) systems were operated with FILL, REACT, SETTLE, DRAW and IDLE modes in the ratio of 0.5:3.5:1:0.75:0.25 for a cycle time of 6 h. The Cu(II) and COD removal efficiency were 90 and 85%, respectively, in the SBR system containing 10 mg/l Cu(II) with the addition of 143 mg/l PAC or 1.0 g PAC per cycle. In the case of 715 mg/l ARH or 5.0 g ARH per cycle addition, the Cu(II) and COD removal efficiency were 85 and 92%, respectively. ARH can be used as an alternate adsorbent to PAC in the simultaneous adsorption and biodegradation wastewater treatment process for the removal of Cu(II). The specific oxygen uptake rate (SOUR) and kinetic studies show that the addition of PAC and ARH reduce the toxic effect of Cu(II) on the activated sludge microorganisms.
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Affiliation(s)
- S A Ong
- School of Chemical Science, Universiti Sains Malaysia, Penang 11800, Malaysia.
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Lim PE, Ong SA, Seng CE. Simultaneous adsorption and biodegradation processes in sequencing batch reactor (SBR) for treating copper and cadmium-containing wastewater. Water Res 2002; 36:667-675. [PMID: 11827329 DOI: 10.1016/s0043-1354(01)00257-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The application of simultaneous adsorption and biodegradation processes in the same reactor is known to be effective in the removal of both biodegradable and non-biodegradable contaminants in various kinds of wastewater. The objective of this study is to evaluate the efficacy of the two processes under sequencing batch reactor (SBR) operation in treating copper and cadmium-containing synthetic wastewater with powdered activated carbon (PAC) as the adsorbent. The SBR systems were operated with FILL, REACT, SETTLE, DRAW and IDLE periods in the ratio of 0.5: 3.5: 1.0: 0.75 :0.25 for a cycle time of 6 h. In the presence of 10 mg/L Cu(II) and 30 mg/L Cd(II), respectively, the average COD removal efficiencies were above 85% with the PAC dosage in the influent solution at 143 mg/L compared to around 60% without PAC addition. Copper(II) was found to exert a more pronounced inhibitory effect on the bioactivity of the microorganisms compared to Cd(II). It was observed that the combined presence of Cu(II) and Cd(II) did not exert synergistic effects on the microorganisms. Kinetic study conducted for the REACT period showed that the addition of PAC had minimized the inhibitory effect of the heavy metals on the bioactivity of microorganisms.
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Affiliation(s)
- Poh-Eng Lim
- School of Chemical Sciences, University Sains Malaysia, Penang, Malaysia.
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