Now showing 1 - 4 of 4
  • Publication
    Hydroxyl radical formation in the hybrid system of photocatalytic fuel cell and peroxi-coagulation process affected by iron plate and UV light
    ( 2020-04-01)
    Nordin N.
    ;
    ; ;
    Ibrahim A.H.
    ;
    ;
    Lee S.L.
    ;
    Ong Y.P.
    The hybrid electrochemical system of photocatalytic fuel cell - peroxi-coagulation (PFC-PC) is a combined technology of advanced oxidation process (AOP) which involve the hydroxyl radical formation for simultaneous degradation of organic pollutant and electricity generation. The p-nitrosodimethylaniline (RNO) spin trapping technique was applied by analyzing the RNO bleaching performance to detect the OH[rad] at the PFC and PC reactors. The presence of UV light showed higher RNO bleaching rate at the PFC reactor (11.7%) with maximum power density (Pmax = 3.14 mW cm−2). Results revealed that the optimum of maximum power density was observed at iron plate size of 30 cm2. UV light became a limiting factor in the PFC system as a power source in the PFC-PC system. Meanwhile, iron plate plays an important role to supply the soluble Fe2+ ions by oxidation process and become a suitable catalyst for in-situ production of H2O2 and OH[rad] through the PC process to degrade the organic molecules.
  • Publication
    Studies on factors affecting unconfined compressive strength of industrial rubber sludge containing heavy metals treated using ordinary Portland cement via stabilization/solidification technique
    High concentration of selected heavy metals within industrial rubber sludge collected from rubber industry wastewater treatment plant has classified the waste as scheduled waste. Special treatment to the waste by using ordinary Portland cement via solidification/stabilization (S/S) technique has been performed in laboratory scale. The objective of this research is to determine related factors that affect unconfined compressive strength (UCS) performance of stabilised/solidified (s/s) cube specimens which contains industrial rubber sludge waste. Other parameters observed include the curing condition (i.e. air and water immersion curing method), waste composition, specimen age and density. The prepared fresh mix were cast in plastic moulds in order to produce 50 mm3 cubical shape specimens and leaved to set approximately 24 to 48 hours. The prepared specimen batches are S1 (90% OPC + 10% waste), S2 (70% OPC + 30% waste), S3 (50% OPC + 50% waste). UCS was performed on respective specimen age of 7 and 28 days. Positive results were obtained as relatively the average compressive strength of 7 day air cured specimens reach 5.25 MPa, 5.28 MPa, and 2.16 MPa for S1, S2 and S3.While, 28 days air cured specimens results are 9.59 MPa, 8.01 MPa, and 1.46 MPa for S1, S2, and S3 respectively. As for water immersion, the compressive strengths are 8.19 MPa, 4.93 MPa, and 1.90 MPa for 7 days, and 7.75 MPa, 10.10 MPa, and 2.11 MPa for 28 days at respective S1, S2 and S3 sequence. As conclusion, the specimens prepared passed the minimum requirement for secured landfill disposal which is at 1 MPa.
      3  38
  • Publication
    Evaluation on physical and chemical properties of treated industrial wastewater sludge containing latex and heavy metals using ordinary Portland cement via stabilization / solidification technique
    Industrial wastewater sludge containing latex collected from rubber industry wastewater treatment plant has classified the waste as scheduled waste due to high concentration of selected heavy metals within it. Laboratory scale of special treatment via solidification/stabilization (S/S) technique has been performed to the waste by using ordinary Portland cement. The objective of this research is to evaluate the chemical properties of the raw waste using X-Ray Fluorescence (XRF) and physical properties related to unconfined compressive strength (UCS) performance of stabilised/solidified (s/s) cube specimens. Other factors took into consideration include the curing condition using air and water immersion curing technique, waste addition percentage, specimen age and density. The fresh mix prepared were cast in plastic moulds internal dimension of 50 mm3 producing cubical shape specimens and cured approximately 24 to 48 hours. The prepared specimen batches are A1 (90% OPC + 10% waste), A2 (70% OPC + 30% waste), A3 (50% OPC + 50% waste). Chemical analyses using XRF indicates that raw sludge contains approximately several heavy metals such as Aluminium (30%), Phosphorus, P (17.5%) and Zinc, Zn (11.7%). UCS testing were conducted on 7 and 28 days of specimen age. Positive average compressive strength results of 7 day air cured specimens reach 5.25 MPa, 5.28 MPa, and 2.16 MPa for A1, A2 and A3. Next, 28 days air cured specimens results are 9.59 MPa, 8.01 MPa, and 1.46 MPa for A1, A2, and A3 respectively. As for water immersion, the compressive strengths are 8.19 MPa, 4.93 MPa, and 1.90 MPa for 7 days, and 7.75 MPa, 10.10 MPa, and 2.11 MPa for 28 days at respective A1, A2 and A3 sequence. Based on the UCS performance, the tested specimens surpassed the minimum requirement for secured landfill disposal which is at 1 MPa.
      36  1
  • Publication
    Analysis of lead (Pb) leaching from stabilized/solidified sample containing rubber sludge waste treated using ordinary Portland cement and rice husk ash
    (American Institute of Physics Inc., 2022-11-18) ;
    Lead (Pb) contaminated sludge originating from industrial rubber wastewater treatment has become a serious problem if been direct disposed in landfill. Lead has been recognized as harmful toxic heavy metals and capable to cause carcinogenic effect to human and other living creatures. The leaching of Pb from this waste can leads to more severe environmental problem associated with the contribution by water run-off, groundwater and surface water contaminations. An attempt to treat the rubber sludge using ordinary Portland cement and rice husk ash using stabilization/solidification technique has been performed in this study. Objective of this study is to evaluate the effectiveness of ordinary Portland cement and rice husk ash mixtures in reducing the leachability of lead in stabilized/solidified specimen. Based on the findings, it is revealed that lead from leaching of sample batches prepared (i.e. OWR1, OWR2 and OWR3) have successfully reduced as compared to the control batches. The combination of ordinary Portland cement and rice husk ash were proven to reduce the leaching of lead into the leachant closed to acceptable limit which was at 15?ppm.
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