Nora’aini Ali

Study on the removal of pesticide in agricultural run off by granular activated carbon

In this batch study, the adsorption of malathion by using granular activated carbon with different parameters due to the particle size, dosage of carbons, as well as the initial concentration of malathion was investigated. Batch tests were carried out to determine the potential and the effectiveness of granular activated carbon (GAC) in removal of pesticide in agricultural run off. The granular activated carbon; coconut shell and palm shells were used and analyzed as the adsorbent material. The Langmuir and Freundlich adsorption isotherms models were applied to describe the characteristics of adsorption behavior. Equilibrium data fitted well with the Langmuir model and Freundlich model with maximum adsorption capacity of 909.1mg/g. The results indicate that the GAC could be used to effectively adsorb pesticide (malathion) from agricultural runoff.

Effect of Conway Medium and f/2 Medium on the growth of six genera of South China Sea marine microalgae.

A study was performed to determine the effect of Conway and f/2 media on the growth of microalgae genera. Genera of Chlorella sp., Dunaliella sp., Isochrysis sp., Chaetoceros sp., Pavlova sp. and Tetraselmis sp. were isolated from the South China Sea. During the cultivation period, the density of cells were determined using Syringe Liquid Sampler Particle Measuring System (SLS-PMS) that also generated the population distribution curve based on the size of the cells. The population of the microalgae genera is thought to consist of mother and daughter generations since these microalgae genera reproduce by releasing small non-motile reproductive cells (autospores). It was found that the reproduction of Tetraselmis sp., Dunaliella sp. and Pavlova sp. could be sustained longer in f/2 Medium. Higher cell density was achieved by genus Dunaliella, Chlorella and Isochrysis in Conway Medium. Different genera of microalgae had a preference for different types of cultivation media.

The formation and characterisation of an asymmetric nanofiltration membrane for ammonia-nitrogen removal: effect of shear rate.

The focus of this research is to study the potential of nanofiltration membrane technology in removing ammonia-nitrogen from the aquaculture system. One of the major fabrication parameters that directly affect the separation performance is shear rate or casting rate during membrane fabrication. In this study, asymmetric polyethersulfone (PES) nanofiltration membranes were prepared at five different shear rates within the range of 67-400 s(-1). Membrane productivity and separation performance were assessed via pure water, salt and ammonia-nitrogen permeation experiments, and their structural properties were determined by employing the combination of the irreversible thermodynamic (IT) model, solution diffusion model, steric hindrance pore (SHP) model and Teorell-Meyers (TMS) model. The study reveals that the alteration of shear rate enormously affects the membrane morphology and structural parameters, hence subsequently significantly influencing the membrane performance. It was found that, membrane produced at the shear rate 200 s(-1) or equivalent to 10s of casting speed during membrane fabrications managed to remove about 68% of ammonia-nitrogen, in which its separation performance is the most favourable by means of highest flux and rejection ability towards unwanted solutes. Besides, from the research findings, nano-membrane technology is a potential candidate for the treatment of aquaculture wastewater.

Nitrogen budget and effluent nitrogen components in aquaponics recirculation system

AbstractIn this study, the dynamics of nitrogen through aquaponics recirculation system was examined by developing a nitrogen budget. The model evaluated total ammonia nitrogen (TAN) production and removal in biofilters, identifying and quantifying the fate of nitrate nitrogen (-N) and determining the system maximum carrying capacity. Of the nitrogen input into the culture tank via feed, 83.8% was recovered from different pool: 39.4% as fish flesh (harvested), 2.1% as mortalities, 34.7% as dissolved inorganic forms of nitrogen and 7.6% as total organic nitrogen. The remaining 16.2% of nitrogen unaccounted for likely was lost as nitrogen gas due to passive denitrification and as volatization of ammonia. Average TAN in the culture tanks was 2.08 mg/L. Under current condition, system loading with fish biomass at average of 68.5% of the maximum predicted. The hydroponic troughs removal efficiency averaged 60.4% TAN per pass. From TAN production, 88% was removed in hydroponic troughs, 11% by passive nitrificat...

The Effect of Concentration of Lawsonia inermis as a Corrosion Inhibitor for Aluminum Alloy in Seawater

Lawsonia inermis also known as henna was studied as a corrosion inhibitor for aluminum alloy in seawater. The inhibitor has been characterized by optical study via Fourier transform infrared spectroscopy (FTIR). The FTIR proves the existence of hydroxyl and carbonyl functional groups in Lawsonia inermis. Aluminum alloy 5083 immersed in seawater in the absence and presence of Lawsonia inermis was tested using electrochemistry method, namely, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PP). EIS and PP measurements suggest that the addition of Lawsonia inermis has caused the adsorption of inhibitor on the aluminum surface. The adsorption behavior of the inhibitor follow Langmuir adsorption model where the value of free energy of adsorption, , is less than 40 kJ/mol indicates that it is a physical adsorption. Finally, it was inferred that Lawsonia inermis has a real potential to act as a corrosion inhibitor for aluminum alloy in seawater.

Removal of pesticide in agricultural runoff using granular-activated carbon: a simulation study using a fixed-bed column approach

AbstractThe use of pesticide and its subsequent release to the environment is a major concern for modern society as concerns over environmental pollution associated with toxic emission are recognized due to contaminants present in pesticide (particularly malathion). Adsorption process using activated carbon is among the most effective techniques for the removal of pesticides in the treatment of various waste streams. The adsorption of pesticide containing malathion in agricultural runoff was investigated using granular-activated carbon (GAC) as the adsorbent; GAC made of coconut, and palm shells were used and their effectiveness in retaining the pesticide is discussed. A fixed-bed column test was performed to simulate the actual condition of adsorption in a continuous manner in a filtration process. Different flow rates were used to evaluate their effects on the column performance, where different breakthrough curves were obtained. The Adam–Bohart breakthrough curve equation was used to predict the breakt...

Preparation and characterization of asymmetric ultrafiltration membrane for effective recovery of proteases from surimi wash water

The wash water generated from the surimi processing industry contains a large amount of proteases which are widely used in the food and biotechnology industries. Asymmetric polysulfone and polyethersulfone ultrafiltration (PSf-UF and PES-UF) membranes with three different polymer concentrations were screened for their abilities to recover proteases from surimi wash water. Inhouse fabricated membranes were prepared via a simple dry/wet phase inversion technique and were characterized in terms of permeability coefficient, membrane morphology and molecular weight cut-off (MWCO). The ability of the UF membranes to remove commercial proteases was tested at various pressures (up to 10 bars). The membrane with the best performance, 15 wt-% PSf-UF, was further tested with actual surimi wash water. The effect of the pH of the feed solution (4 to 8) in the pre-treatment stage was also evaluated to recover the highest amount of proteases. The highest retention of protease was 96% with a flux of 25.6 L/(m2·h) which was achieved with the 15 wt-% PSf-UF membrane.

Modelling the Solid Waste Flow into Sungai Ikan Landfill Sites by Material Flow Analysis Method

The purpose of this paper is to model the material flow of solid waste flows at Kuala Terengganu by using Material Flow Analysis (MFA) method, generated by STAN Software Analysis. Sungai Ikan Landfill has been operated for about 10 years. Average, Sungai Ikan Landfill receive an amount around 260 tons per day of solid waste. As for the variety source of the solid waste coming from, leachates that accumulated has been tested and measured. Highest reading of pH of the leachate is 8.29 which is still in the standard level before discharging the leachate to open water which pH in between 8.0-9.0. The percentages of the solid waste has been calculated and seven different types of solid waste has been segregated. That is, plastics, organic waste, paper, polystyrene, wood, fabric and can. The estimation of the solid waste that will be end as a residue are around 244 tons per day.

Development of nanofiltration membrane separation prediction system for binary salt solutions

AbstractThe previous studies on nanofiltration (NF) mainly focused on the work to update the existing predictive models to enhance its application in order to optimize the separation prediction. There is still lack of research which successfully creates a user-friendly system for separation process prediction optimization. In this study, a MATLAB®-based NF prediction system (NF-BIN) utilizing Donnan Steric Pore model with application of m-file programming and graphical user interface was developed specifically for binary salt solutions treatment. Prior to the prediction, locally fabricated polyethersulfone membranes with three different polymer concentrations, 19, 21, and 23%, were characterized in terms of pore radius, rp ratio of membrane thickness to porosity, Δx/Ak and effective charge density, Xd using uncharged, and charged solutes rejection data. Further the rejection prediction performance was carried out to predict the percentage contribution of ion transport mechanism of three transport modes: d...

Characterization Study of a Highly Specific Affinity Membrane for Trypsin Purification

This study aimed to characterize a highly specific affinity membrane for trypsin separation. The basic membrane was fabricated using 15% polysulfone via phase inversion technique. Membrane surface modification was employed by immersing the native membrane into the chitosan solution for 60 minutes dip times. Further modification was performed to activate the PSf/chitosan hybrid membrane using glutaraldehyde before ligand immobilization. The prepared affinity membrane was characterized in term of morphology using scanning electron microscope and the presence of aldehyde group and ovomucoid were confirmed by ATR-FTIR. Performance of affinity membrane was valuted by adsorption study of trypsin enzyme. The observed results show that the developed affinity membrane, with 0.7 mg/ml ligands was able to adsorb trypsin for about 0.219 mg/cm2 membrane