Hybrid adsorption-membrane process for reclamation of bio-treated palm oil mill effluent for boiler-feed reuse /
Increased water shortages and waterway pollution are major problems posing risks to freshwater resources, with the highest risk from the industries. Palm oil industry is one of those industries attributed with the risks in Malaysia. As reclaimed water has been recognized as a vital and drought-proof...
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| Main Author: | |
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| Format: | Thesis |
| Language: | English |
| Published: |
Kuala Lumpur :
Kulliyyah of Engineering, International Islamic University Malaysia,
2015
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| Subjects: | |
| Online Access: | http://studentrepo.iium.edu.my/handle/123456789/4862 |
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| Summary: | Increased water shortages and waterway pollution are major problems posing risks to freshwater resources, with the highest risk from the industries. Palm oil industry is one of those industries attributed with the risks in Malaysia. As reclaimed water has been recognized as a vital and drought-proof water source to ensure economic and agricultural activities, this research addresses the reclamation of biotreated palm oil mill effluent (BPOME), applying a developed hybrid adsorption-membrane process to produce boiler-feed water for low-pressure operating industrial boilers. The process consists of an upstream adsorption process to reduce foulants' level for longer membrane life and enhanced flux. Low-cost powdered activated carbons (PACs) applied for the process were produced from empty fruit bunch (EFB) using steam and CO2 activation. The steam activated PAC was selected based on performance in the COD, Mn and H2S removals. Optimization study using Full Factorial Design (FFD) was carried out on the selected PAC with 10 responses, and it was observed that many of the boiler-feed constituents of concern have been reduced close to USEPA benchmark, except for COD, Hardness, Alkalinity and TDS. Using the optimized results, further optimization using Central Composite Design (CCD) was carried out to examine the effects of involved variables on adsorption efficacy with COD, Hardness and Alkalinity as responses. The ANOVAs suggested that all optimization models and factors were significant with R2 values of predicted and actual data close to unity. The adsorption results indicated that levels of most boiler-feed constituents of concern were further significantly reduced. Equilibrium studies were carried out by fitting the adsorption experimental data to four adsorption isotherm models in order to evaluate the applicability of the sorption process as a unit operation in the hybrid system. Langmuir isotherm was observed to fit best as it exhibited R2 values of 1.00 for COD, and 0.9999 for H2S and Mn sorption equilibria, respectively. The controlling mechanism of the adsorption processes was also examined using four kinetic models, and pseudo-second order kinetic model was found to fit best with R2 values of 1.00 for COD, H2S and Mn. The optimized result was applied in the bench scale hybrid process study. Downstream membrane filtration of the adsorbed BPOME (ABPOME) using five low pressure membranes (LPMs) were carried out and their filtration mechanisms were studied using Hermia's models at constant pressures of 40, 80 and 120 kPa. Cake filtration model dominated all other fouling mechanisms with the highest R2 values, but not without other mechanisms participating at the onset of the membrane processes. The cake analysis revealed that the cake was moderately compressible with compressibility factors (z) ranging from 0.3 to 0.52. Lower MWCO membranes (1 and 5 kDa) were found to be unsuitable for compressibility factor determination due to the negative compressibility factors they yielded. The final effluent of the hybrid process was evaluated and the constituents' levels for 1 and 5 kDa ultrafiltration membranes were within USEPA acceptable standards for low-pressure boiler-feed, cooling and process waters for cement, petroleum and coal industries without further treatment. The hybrid system's operation consumed 37.13Wh m-3 of energy at 120 kPa of applied pressure, which is far lesser than the typical energy requirement range (0.8 – 1.0 kWh m-3) for wastewater reclamation |
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| Physical Description: | xxvi, 301 leaves : ill. ; 30cm. |
| Bibliography: | Includes bibliographical references (leaves 240-258). |