Now showing 1 - 8 of 8
  • Publication
    Microplastics in facial cleanser: extraction, identification, potential toxicity, and continuous-flow removal using agricultural waste–based biochar
    Microplastic (MP) is an emerging contaminant of concern due to its ubiquitous quantity in the environment, small size, and potential toxicity due to strong affinity towards other contaminants. In this work, MP particles (5–300 μm) were extracted from a commercial facial cleanser and determined to be irregular polyethylene (PE) microbeads based on characterization with field emission scanning electron microscopy (FESEM) and Raman spectroscopy. The potential of extracted MP acting as toxic pollutants’ vector was analyzed via adsorption of methylene blue and methyl orange dye where significant dye uptake was observed. Synthetic wastewater containing the extracted MP was subjected to a continuous-flow column study using palm kernel shell and coconut shell biochar as the filter/adsorbent media. The prepared biochar was characterized via proximate and ultimate analysis, FESEM, contact angle measurement, atomic force microscopy (AFM), and Fourier transform infrared (FTIR) spectroscopy to investigate the role of the biochar properties in MP removal. MP removal performance was determined by measuring the turbidity and weighing the dry mass of particles remaining in the effluent following treatment. Promising results were obtained from the study with highest removal of MP (96.65%) attained through palm kernel shell biochar with particle size of 0.6–1.18 mm and continuous-flow column size of 20 mm. Graphical abstract: [Figure not available: see fulltext.].
      7  38
  • Publication
    Column-based removal of high concentration microplastics in synthetic wastewater using granular activated carbon
    ( 2023-01-01)
    Amirah Mohd Napi N.n.
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    ;
    Adli Hanif M.
    ;
    ; ;
    Syafiuddin A.
    ;
    Boopathy R.
    Microplastic (MP) is an emerging contaminant of concern due to its abundance in the environment. Wastewater treatment plant (WWTP) can be considered as one of the main sources of microplastics in freshwater due to its inefficiency in the complete removal of small MPs. In this study, a column-based MP removal which could serve as a tertiary treatment in WWTPs is evaluated using granular activated carbon (GAC) as adsorbent/filter media, eliminating clogging problems commonly caused by powder form activated carbon (PAC). The GAC is characterized via N2 adsorption–desorption isotherm, field emission scanning electron microscopy, and contact angle measurement to determine the influence of its properties on MP removal efficiency. MPs (40–48 μm) removal up to 95.5% was observed with 0.2 g/L MP, which is the lowest concentration tested in this work, but still higher than commonly used MP concentration in other studies. The performance is reduced with further increase in MP concentration (up to 1.0 g/L), but increasing the GAC bed length from 7.5 to 17.5 cm could lead to better removal efficiencies. MP particles are immobilized by the GAC predominantly by filtration process by being entangled with small GAC particles/chips or stuck between the GAC particles. MPs are insignificantly removed by adsorption process through entrapment in GAC porous structure or attachment onto the GAC surface.
      1
  • Publication
    Microplastics and nanoplastics: Recent literature studies and patents on their removal from aqueous environment
    The presence of microplastics (MP) and nanoplastics (NP) in the environment poses significant hazards towards microorganisms, humans, animals and plants. This paper is focused on recent literature studies and patents discussing the removal process of these plastic pollutants. Microplastics and nanoplastics can be quantified by counting, weighing, absorbance and turbidity and can be further analyzed using scanning electron microscopy (SEM), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, surface-enhanced Raman spectroscopy and Raman tweezers. Mitigation methods reported are categorized depending on the removal characteristics: (i) Filtration and separation method: Filtration and separation, electrospun nanofiber membrane, constructed wetlands; (ii) Capture and surface attachment method: coagulation, flocculation and sedimentation (CFS), electrocoagulation, adsorption, magnetization, micromachines, superhydrophobic materials and microorganism aggregation; and (iii) Degradation method: photocatalytic degradation, microorganism degradation and thermal degradation; where removal efficiency between 58 and 100% were reported. As these methods are significantly distinctive, the parameters which affect the MP/NP removal performance e.g., pH, type of plastics, presence of interfering chemicals or ions, surface charges etc. are also discussed. 42 granted international patents related to microplastics and nanoplastics removal are also reviewed where the majority of these patents are focused on separation or filtration devices. These devices are efficient for microplastics up to 20 μm but may be ineffective for nanoplastics or fibrous plastics. Several patents were found to focus on methods similar to literature studies e.g., magnetization, CFS, biofilm and microorganism aggregation; with the addition of another method: thermal degradation.
      36  2
  • Publication
    Removal of molluscicide compound: A comparison of metaldehyde removal performance between rubber-based aerobic granules and molasses-based aerobic granules
    Rubber-based aerobic granules (RAGS) were developed in a bioreactor. Outside of the bioreactor, RAGS were supplemented with molasses wastewater to produce molasses-based aerobic granules (MAGS). Rates of RAGS and MAGS elimination and growth were calculated across a range of 180–330 mg/L of metaldehyde. Metaldehyde removal rates for RAGS and MAGS were 84 % and 85 %, correspondingly. Rates of biodegradation (K1) ranged from 0.402 to 0.063 h−1 for RAGS and from 0.404 to 0.065 h−1 for MAGS. There was a negative correlation between metaldehyde concentration and the first-order rate constant. MAGS had somewhat higher metaldehyde removal capacities than RAGS, with a lower Ks value (234 mg/L) than RAGS (282 mg/L). The MAGS had a higher μmax (0.188 day−1) value than the RAGS (0.129 day−1). RAGS and MAGS show promise for use in aerobic granular sludge remedy of wastewater due to their ability to degrade metaldehyde.
      1
  • Publication
    Microplastics and nanoplastics: Recent literature studies and patents on their removal from aqueous environment
    ( 2022-03-01)
    Muhammad Adli Hanif
    ;
    ; ; ; ;
    Jalil A.A.
    The presence of microplastics (MP) and nanoplastics (NP) in the environment poses significant hazards towards microorganisms, humans, animals and plants. This paper is focused on recent literature studies and patents discussing the removal process of these plastic pollutants. Microplastics and nanoplastics can be quantified by counting, weighing, absorbance and turbidity and can be further analyzed using scanning electron microscopy (SEM), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, surface-enhanced Raman spectroscopy and Raman tweezers. Mitigation methods reported are categorized depending on the removal characteristics: (i) Filtration and separation method: Filtration and separation, electrospun nanofiber membrane, constructed wetlands; (ii) Capture and surface attachment method: coagulation, flocculation and sedimentation (CFS), electrocoagulation, adsorption, magnetization, micromachines, superhydrophobic materials and microorganism aggregation; and (iii) Degradation method: photocatalytic degradation, microorganism degradation and thermal degradation; where removal efficiency between 58 and 100% were reported. As these methods are significantly distinctive, the parameters which affect the MP/NP removal performance e.g., pH, type of plastics, presence of interfering chemicals or ions, surface charges etc. are also discussed. 42 granted international patents related to microplastics and nanoplastics removal are also reviewed where the majority of these patents are focused on separation or filtration devices. These devices are efficient for microplastics up to 20 μm but may be ineffective for nanoplastics or fibrous plastics. Several patents were found to focus on methods similar to literature studies e.g., magnetization, CFS, biofilm and microorganism aggregation; with the addition of another method: thermal degradation.
      2  32
  • Publication
    Effect of Aeration Rate on Specific Oxygen Uptake Rate (SOUR) in Treating Chemical Oxygen Demand (COD) in Domestic Wastewater
    Specific oxygen uptake rate (SOUR) is significant parameter to determine the microbial activity and examined the effluent quality in biological wastewater treatment. Chemical oxygen demand (COD) is the major indicator in monitoring the effluent quality in relation on its removal mainly depends on the microbial activity in the activated sludge. So, this research is conducted to study the effect of aeration rate on SOUR and determined the best oxygen requirement in removing COD in domestic wastewater. The procedure was carried out by using domestic wastewater as the seed sludge in sequencing batch reactor. The reactor with working volume of 2L was operating 6 cycles in 24 hours with five phases (feeding, aeration, settle, draw and idle). The aeration time is fixed to 2.5 hours. The dissolved oxygen and COD readings were recorded with four types of aeration rate adjusted at 1L, 2L, 3L and 4L / min daily for 7 days. The result indicates that, 3L/min gives the highest SOUR which reflects that the high activity of microbial in this condition. Besides, the effluent also shows the highest COD removal efficiency on 3L/min of aeration rate. So, as a conclusion the best oxygen requirement for the microbial to carry out their activities on aeration rate of 3L/min.
      10  36
  • Publication
    Hydrogen sulfide removal from fermentative biohydrogen process: Effect of ZSM-5 zeolite loading
    ( 2024-03-01)
    Asman M.K.A.
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    Wong Y.S.
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    Hanif M.A.
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    ; ; ;
    Hamdzah M.
    The production and consumption of biohydrogen is growing because it is a “green,” renewable energy that can be obtained in a relatively cost-effective manner through anaerobic digestion. Biohydrogen produced from biomass is a viable source of renewable energy; nevertheless, the presence of highly toxic and corrosive hydrogen sulfide (H2S) in the process can hinder the quality of biohydrogen production and limit its application in energy conversion equipment. Consequently, the goal of the research was to assess the feasibility of using ZSM-5 zeolite for H2S adsorption that function as activating agent to enhance biohydrogen quality under thermophilic conditions. The effect of ZMS-5 Zeolite loading (0.2–1.0 g) on biohydrogen production via dark fermentation from mixed fruit waste (MFW) was investigated using anaerobic sludge from a sewage treatment plant. The pH of the broth mixture was adjusted to 6.0, anaerobic conditions were created by purging it with nitrogen gas, and the temperature of the fermentative biohydrogen process was maintained at 60°C. Meanwhile, the H2S adsorption test was run at ambient temperature with flow rates (100 ml/min) and an H2S inlet concentration of 10000 ppm. The results indicate that the Z + H2S exhibit spectral lines corresponding to the S-H asymmetric stretching vibration of H2S at 2345.97 cm−1. The ideal adsorption capacity is at 0.8 g with yet, increasing the dosage amount of adsorbents, increases the time required for the adsorbent to achieve 90% saturation. The non-linear curve fitting demonstrated that the adsorption kinetics of all dosages used followed those of the Avrami kinetic model. This approach of using ZSM-5 zeolite for H2S removal provides an advantage in terms of minimizing environmental pollution and having great potential uses in industrial processes.
      41  2
  • Publication
    Chemical extraction and quantification of extracellular polymeric substances in unspiked-metaldehyde and spiked-metaldehyde of rubber aerobic granular sludge and molasses aerobic granular sludge
    ( 2023-12-01)
    Saad A.M.
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    ;
    Naimah Ibrahim
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    The building blocks of biofilm are called extracellular polymeric substances (EPSs), and they are composed of biopolymers. The optimal properties of EPSs include chemical interactions, resistance to dehydration, and resilience in the face of hazardous shock loads. It is necessary to have an understanding of EPSs extraction, composition, and the biomatrix's reaction to contaminants. This research aims to conduct chemical extraction to determine the amounts of EPSs found in unspiked-metaldehyde and spiked-metaldehyde rubber aerobic granular sludge (rAGS) and newly invented molasses aerobic granular sludge (mAGS). The rAGS was produced by feeding synthetic wastewater into sequencing batch reactors (SBRs). The mAGS was developed by adding the rAGS with different volumes of molasses wastewater. The EPSs were successfully extracted and identified by quantifying the number of proteins and carbohydrates present in each rAGS and mAGS condition. Hydroxyl, carboxyl, and amino groups showed that rAGS and mAGS EPSs contained carbohydrates and proteins. The compositions of the EPSs showed a strong correlation with the concentrations of metaldehyde in the spiked-metaldehyde rAGS and mAGS samples. When the total EPSs are taken into consideration, both rAGS and mAGS that are formed are effective treatments for metaldehyde treatment in wastewater.
      5  23