Search

This paper evaluates the performance of Scirpus grossus plant in polishing treatment of palm oil mill effluent (POME) treatment. The experiments were run in batch for planted and unplanted systems serve as control treatment. The experiments were run in triplicate to study the performance of Scirpus grossus in organics removal via chemical oxygen demand (COD), suspended solid (SS) and nutrients removal efficiencies. The POME samples were measured every 3 days for 18 days of treatment duration. The growth of Scirpus grossus was observed in term of number of plants, plants height, and the plants weight. From the result, Scirpus grossus plant was capable to enhance the pollutant removal efficiencies with 91% of SS, 88% of COD, 96% of ammonia, 99% total nitrogen and 56% of total phosphorus. While for control systems the removal achieved 52% of SS, 83% of COD, 93% of ammonia, 92% total nitrogen and 45% of total phosphorus. Therefore, Scirpus grossus plants have the great potential in nutrients removal and suitable as phytoremediation plant in POME treatment. [ABSTRACT FROM AUTHOR]

Palm oil mill effluent (POME) from crude palm oil extraction process imposed a serious environmental threat to the nearby water resources due to high solid and organic concentration. Constructed wetland treatment systems (CWTS) has been identified as an ideal alternative solution to the POME treatment in order to comply with the regulation concern by the Department of Environment, Malaysia. CWTS offers sustainable and environmentally friendly approach with great potential for pollutant removal. In this study, three hydraulic retention time (HRT) was used in horizontal sub-surface flow CTWS with 3, 6 and 12 days with recirculation flow method to polish POME within 30 and 36 days duration. The gravelsand bed was used as a medium for Cyperus alternifolius plant growth in the CWTS. The unplanted systems were served as control systems. The performance of horizontal sub-surface flow CTWS was measured with regards to suspended solids (SS), chemical oxygen demand (COD), ammoniacal nitrogen (NH3-N), total nitrogen (TN) and total phosphorus (TP) removal percentage and plant growth. The performance of COD and NH3-N was found to be highest in 12 days HRT with 95% removal while for SS achieved 93% removal in 6 days HRT. The growth rate of Cyperus alternifolius plant shows that the plant height increased 6.9%, 4.4%, and 7.1% respectively, for 3, 6 and 12 days HRT. In conclusion, the horizontal sub-surface flow CTWS successfully treat POME with great pollutant removal with higher HRT. [ABSTRACT FROM AUTHOR]

A study was conducted to investigate the efficiency of iron oxide nanoparticle (FeONPs) adsorption for removing of DOM in landfill leachate. FeONPs was directly prepared via sodium borohydride (KBH4) reduction method. Adsorption kinetics, isotherm and thermodynamic studies were developed to design the model for DOM removal. Pseudo first-order and pseudo second-order model have been studied to fit the experimental data. The regression results showed that the adsorption kinetics were more accurately represented by a pseudo second-order model. The Weber-Morris intraparticle diffusion model was used to analyze the adsorption kinetics data. The plot of qt versus t1/2 represents multi linearity, which showed that the adsorption processes occurred in more than one step. Adsorption isotherms were analyzed by Langmuir, Freundlich, Tempkin and Dubinin-Radushkevich, isotherms model. Equilibrium data were well fitted to the Dubinin-Radushkevich isotherm model. Maximum monolayer adsorption based on Langmuir was calculated to be 21.74 mg/g. Thermodynamic parameters such as free energy changes (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) were evaluated between temperatures of 25 °C and 40 °C. The ΔG° was noticed progressively decrease from -9.620 -9.820 -10.021, and -10.222 kJ/mol as the temperature increase. The ΔH° and ΔS° values were found to be 2.350 kJ/mol and 40.165 J/mol.K respectively. The results showed that the overall adsorption process was endothermic and spontaneous. The results from this study suggested that FeNPs could be a viable adsorbent in managing higher DOM problems associated with landfill leachate. [ABSTRACT FROM AUTHOR]

In this study, composite adsorbent was produced from the combination of activated carbon (AC) and calcite by four (4) different mixing ratios (AC:Calcite) of 9:1, 7:3, 1:1, 3:7, 1:9. The mixture was mixed with alginate as the binder. The composite adsorbent was tested in batch of experimental study to observe the effectiveness of removing COD and Fe2+ from sample of leachate collected from semi-aerobic sanitary landfill at Pulau Burung, Penang, Malaysia. The effect on contact time was conducted to observe its impact on the adsorption of COD and Fe2+. Besides, the adsorption kinetic model was also conducted to study the mechanism of adsorption process by applying pseudo-first order and pseudo- second-order rate equations. Based on experimental results, optimum removal of COD and Fe2+ was obtained at mixing ratio of 7:3 with optimum removal of 54.6% for COD and 68.06% for Fe2+. This result indicates that high amount of AC in mixing ratio of adsorbent contributed to the highest removal of both COD and Fe2+. In addition, the study also proves that a combination of AC and calcite has improved the adsorption efficiency. The results of adsorption kinetic model indicate that both COD and Fe2+ followed the pseudo-second order kinetic model which means that the chemisorptions is the favorable mechanism of adsorption process. [ABSTRACT FROM AUTHOR]

In this study, chicken feather fiber was used as a raw material to prepare a non-expensive adsorbent by pyrolysis without chemical activation. The main pollutants treated in this study were chemical oxygen demand (COD) and ammoniacal nitrogen (NH3-N) from shrimp pond wastewater containing high concentrations of nutrients, which caused the eutrophication phenomenon in adjacent water. Batch adsorption studies were performed to investigate the effect of pH (5-8), mass of adsorbent (0.5-3 g), and shaking time (0.5-2 h) on the removal efficiency of COD and NH3-N. Experimental results showed that the optimum conditions were as follows: pH 5, 0.5 g of adsorbent, and 0.5 h of shaking. Under these conditions, 34.01% and 40.47% of COD and NH3-N were removed, respectively, from shrimp pond wastewater. The adsorption processes were best described by the Langmuir isotherm model for COD and NH3-N removal, with maximum monolayer adsorption capacity of 36.9 and 7.24 mg/g for COD and NH3-N, respectively. The results proved that chicken feather could remove COD and NH3-N from shrimp pond wastewater. However, further studies on thermal treatment should be carried out to increase the removal efficiency of pyrolyzed chicken feather fiber. [ABSTRACT FROM AUTHOR]

In this research, the activated carbon prepared from tropical plant waste based Casuarinas Equisetifolia plant was activated through chemical activation by using potassium hydroxide (KOH) as the activating agent. The raw sample was carbonized following conventional heating via electric furnace at 600°C with the increasing temperature 30°C/minutes in one hour which was selected as the optimum condition. The prepared activated carbons exhibit mesoporous with the pore diameter within 0.2μm to 20μm. From the Scanning Electron Microscopy (SEM) micrographs, the morphology of the activated carbon indicated that they demonstrated high pore development on it surfaces. The effects of initial pH, contact time and adsorbent dosage onto the adsorption performances were evaluated through batch adsorption study. The COD removal increased when the adsorbent dosage was increased. The adsorption of COD and colour were best fitted by the Freundlich isotherm model compared to ammonia, which the correlation regressions, R2 were 0.8451, 0.8315 and 0.6608, respectively. The result of the preliminary of the experimental indicated that the Casuarinas Equisetifolia plant is a promising raw material suitable for turning from waste into wealth. [ABSTRACT FROM AUTHOR]

Coagulation-flocculation has been extensively applied for semi-aerobic landfill leachate treatment, prior to other treatment methods. Opting for alternative other than conventional aluminium-based coagulants, mechanically treated starch from oil palm trunk waste had been tested as coagulant for semi-aerobic landfill leachate treatment. FTIR and corresponding elemental analysis had revealed its dominant functional groups like hydroxyl, carboxyl and amine, insinuating existences of starch, fatty acids, proteins, phosphonates, ash and small traces of lignin. Jar test using partially stabilised semi-aerobic landfill leachate from Pulau Burung Landfill Site had shown that this particular botanical coagulant could remove suspended solids and COD in semi-aerobic landfill leachate, though the efficiencies were relatively much lower compared to those of polyaluminium chloride (PAC). Apparently, it was more suitable to be applied as coagulant aid in tandem with PAC, augmenting PAC coagulation performance with 12-16% of improvement. The findings of this first ever attempt had unravelled the potential of oil palm trunk waste in semiaerobic leachate treatment. [ABSTRACT FROM AUTHOR]

Activated carbon with high surface area was successfully produced from banana pseudo-stem through a single step chemical activation process. The effect of activation parameters such as types of activating chemical (ZnCl2 and H3PO4), impregnation ratios (1:1, 1:2, 1:3, 1:4 and 1:5 precursor/activating agent), activation time (30, 60, 90 and 120 min) and activation temperature (400, 500, 600, 700 and 800 °C) were evaluated based on optimum product yield and iodine number. The optimized parameters were found at impregnation ratio of 1:2 using ZnCl2, activation time and the activation temperature of 60 min and 600 °C respectively. The product obtained from optimum parameters was further investigate using chemical and textural characteristic by using N2 adsorption-desorption measurement, elemental analyser CHNS, SEM, FTIR. The result suggested that the AC possessed of mesoporous structure. BET surface area, total pore volume and pore diameters of the AC prepared from optimum condition were 1329.5 m²/g, 1.16 cm³/g and 3.8 nm respectively. [ABSTRACT FROM AUTHOR]