The mycelial growth kinetics, cadmium biosorption capacity and main governing biosorption mechanism of Pleurotus ostreatus (oyster mushroom) have been determined in this study. The fungus mycelium exhibits a sigmoidal (S-shaped) growth curve in which the growth rates for the lag and exponential phases are 0.1 and 0.31 g/L.day, respectively. The grown fungus is subjected to elemental, infra-red and scanning electron microscopy-energy dispersive x-ray spectroscopy analyses while biosorption data are fitted to established adsorption isotherm models, namely, Langmuir, Freundlich and Dubinin-Radushkevich. It is strongly suggested that the main governing mechanism involved is chemisorption due to good fitting of biosorption data to Langmuir and Dubinin-Radushkevich models with possibility of involvement of both ion exchange and complexation. Data presented in the study are very useful for design of future pilot-or industrial-scale biosorption water purification system.Running title: Biosorption of cadmium using Pleurotus ostreatus

The potential of Pleurotus ostreatus spent mushroom compost (PSMC) as a green biosorbent for nickel (II) biosorption was investigated in this study. A novel approach of using the half-saturation concentration of biosorbent to rapidly determine the uptake, kinetics and mechanism of biosorption was employed together with cost per unit uptake analysis to determine the potential of this biosorbent. Fifty per cent nickel (II) biosorption was obtained at a half-saturation constant of 0.7 g biosorbent concentration, initial pH in the range of 4-8, 10 min contact time, 50 mL 50 mg/L nickel (II) initial concentration. The experimental data were well fitted with the Langmuir isotherm model and the maximum nickel (II) biosorption was 3.04 mg/g. The results corresponded well to a second pseudo order kinetic model with the coefficient of determination value of 0.9999. Based on FTIR analysis, the general alkyl, hydroxyl or amino, aliphatic alcohol and carbonyl functional groups of biosorbent were involved in the biosorption process. Therefore, biosorption of nickel (II) must involve several mechanisms simultaneously such as physical adsorption, chemisorption and ion exchange. Cost comparison for PSMC with Amberlite IRC-86 ion exchange resin indicates that the biosorbent has the potential to be developed into a cost effective and environmentally friendly treatment system.

Carbamazepine is an anti-epileptic pharmaceuticalcompound which is frequently detected in wastewater. However, this compound is hardly degraded naturally due to its persistency. Thus, carbamazepine presents in water stream and household water supply as well as wastewater treatment plant. This paper focuses on various species of fungi and bacteria used in carbamazepine biodegradation and the carbamazepine degrading-enzymes involved in the degradation pathways. Selected research papers on carbamazepine biodegradation using fungi and bacteria were reviewed. The efficiency and approaches in term of methodologies and technologies used were highlighted in this paper. Such study sheds light on gaps of study and future research direction on carbamazepine biodegradation.

The potential of Pleurotus ostreatus as biosorbent for cadmium (II) removal was investigated. The maximum cadmium (II) removal was found to be at 85%, under the optimum condition of 0.5 g Pleurotus ostreatus biosorbent concentration, initial pH 6, 10 minutes contact time, 10 mg/L cadmium (II) concentration in 50 mL solution, at 125 rpm on orbital shaker and at room temperature (26 ± 1 °C). The application of Pleurotus ostreatus as biosorbent in electroplating industrial wastewater was also investigated. This study is pivotal for further modeling and scaled up pilot study in alternative sustainable heavy metals removal technology development by deploying Pleurotus ostreatus biosorbent.

This study focuses on activated carbon preparation from spent mushroom farming waste (SMFW) via chemical activation using Box-Behnken design (BBD) of Response Surface Methodology (RSM). Potassium hydroxide (KOH) functions as activating reagent and it plays an important role in enhancing the activated carbon porosity. Three input parameters and two responses were evaluated via this software generated experimental design. The effects of three preparation parameters of impregnation ratio, activation time and activation temperature as well as two responses of carbon yield and iodine number were investigated. The optimum conditions for preparing activated carbon from SMFW was found at SMFW: KOH impregnation ratio of 0.25, activation time of 30 min and activation temperature of 400 o C which resulted in 28.23 % of carbon yield and 314.14 mg/g of iodine number with desirability of 0.994. The predicted results were well corresponded with experimental results. This study is important in economical large scale SMFW activated carbon preparation for application study of adsorption process for metal treatment in wastewater with minimum chemical and energy input.Keywords: activated carbon, spent mushroom farming waste, Box-Behnken design, response surface methodology Abstrak Kajian ini memfokuskan penyediaan arang teraktif daripada sisa tanaman cendawan terpakai melalui reka bentuk box-behnken (BBD) dari kaedah gerak balas permukaan (RSM). Potasium hidroksida (KOH) berperanan sebagai agen pengaktifan dan penting untuk meningkatkan liang arang teraktif. Tiga parameter input dan dua respon telah dinilai oleh perisian ini yang dihasilkan oleh rekabentuk eksperimen. Kesan daripada penyediaan tiga parameter iaitu nisbah pemadatan, masa pengaktifan dan suhu pengaktifan serta dua respon iaitu hasil arang teraktif dan nilai iodin telah disiasat. Keadaan optimum dalam penyediaan arang teraktif telah didapati pada nisbah SMFW: KOH iaitu 0.25, tempoh pengaktifan selama 30 min dan suhu pengaktifan 400 °C, di mana ia menghasilkan jumlah maksimum arang teraktif sebanyak 28.23 % dan nilai iodin yang boleh diterima iaitu sebanyak 314.14 mg/g dengan ketepatan 0.994. Keputusan yang telah diramalkan adalah seiring dengan keputusan eksperimen. Kajian ini adalah penting dalam penyediaan arang teraktif secara berskala besar dengan ekonomi daripada sisa tanaman cendawan terpakai untuk kajian proses penjerapan terhadap rawatan logam dalam air sisa dengan input bahan kimia dan tenaga yang minimum. ISSN -2506 Nurul-Shuhada et al: OPTIMIZATION OF ACTIVATED CARBON PREPARATION FROM SPENT MUSHROOM FARMING WASTE (SMFW) VIA BOX-BEHNKEN DESIGN OF RESPONSE SURFACE METHODOLOGY 462Kata kunci: karbon teraktif, sisa tanaman cendawan terpakai, reka bentuk Box-Behnken, kaedah gerak balas permukaan Introduction Activated carbon (AC) is a carbonaceous material with large surface area and high porosity. The surface area and pore size distribution are important factors in determination of AC performance. The macropores act as the entrance to the AC, while the m...

Surface sterilization is a vital step in preparation of healthy and viable explants in tissue culture. Most surface contaminants can be eliminated by surface sterilization with a suitable sterilizing agent. The study aimed to present an effective disinfection method for Clinacanthus nutans shoot regeneration using nodal segments. A total of four different sterilization approaches were conducted by treating nodal explants with various concentrations of sterilizing agent. Sterilizing agents used were Rhizophora apiculata Pyroligneous acid (PA), sodium hypochlorite (Clorox) thiophanate-methyl (fungicide), and Mercuric chloride (HgCl2). Nodal explant then was cultured on plant growth regulator-free Murashige and Skoog (MS) basal medium. This study sterilizing agents revealed that PA showed strong bactericidal activity. However, it led to a high number of fungal contaminations. The pyroligneous acid did not exhibit a strong potential as a disinfectant for C. nutans nodal explant. Overall, HgCl2 exhibits the best reduction in fungal contamination and gives a significant result with thiophanate-methyl fungicide. Surface sterilization with mercuric chloride (0.2%) for 1 hour was the optimum concentration and duration, which resulted in the highest percentage of nodal explant survival and viability. All viable nodal segments developed into shoots. It had been concluded that the best surface sterilization agent was HgCl2.

The ability of Pleurotus ostreatus spent mushroom compost for the biosorption of Iron (III) from aqueous solutions was investigated. The study was conducted in batch experiments under varying operating conditions. The optimum Iron (III) biosorption was achieved at an initial pH ranging from 4 to 5, contact time of 10 minutes and initial Iron (III) concentration of 50 mg/L using half-saturation constant of 0.4 g biosorbent dosages. The results indicated that the Iron (III) biosorption onto Pleurotus ostreatus spent mushroom compost were well fitted with the Langmuir isotherm model and a second-pseudo order kinetic model.

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