Background (Metroxylon spp.) waste is an inexpensive and abundantly available material with the characteristics of a good adsorbent for treating dye from wastewater. We studied the effectiveness of alkali and acid modification in enhancing the adsorption capacity of sago waste. The untreated and treated adsorbent was characterized by FTIR, elemental analysis and BET surface area. The capacity of each adsorbent to adsorb MB was evaluated at different pH values, adsorbent dosage and initial dye concentrations and contact time. Results According to the results obtained, alkali treatment more than doubled the sorption capacity of sago waste by increasing the porosity, surface area and number of adsorption sites. The alkali-treated material also adsorbed significantly more than many known biosorbents. The effects of the initial concentration of methylene blue, solution pH and adsorbent dosage on methylene blue removal are reported. Equilibrium data were best represented by the Langmuir isotherm model with adsorption capacities of 83.5, 212.8 and 36.82 mg/g for untreated, potassium hydroxide-treated and phosphoric acid-treated sago wastes, respectively. The kinetics of adsorption were best described by a pseudo-second-order model (R 2 = 0.999). Conclusions The alkali treatment of sago waste demonstrates the use of a low-cost agricultural waste and a simple modification process to produce an effective adsorbent for removing cationic dye from wastewater.

− This paper aims to investigate the potential use of cempedak durian peel (CDP) from Negara Brunei Darussalam, which is low-cost, locally available, eco-friendly and highly efficient to remove methyl violet (MV) dye from aqueous solutions. The time required for equilibrium to be reached is 2.0 h with no adjustment of pH necessary. FTIR analysis was indicative of the involvement of -COOH and C=O functional groups in adsorption process. The Langmuir model provided the best fit with maximum adsorption capacity of 0.606 mmol g -1. Thermodynamics data indicate that the adsorption is spontaneous, feasible and endothermic in nature. Best regeneration of CDP's adsorption ability is achieved by base solution, showing about 95% removal efficiency of MV even after 5 cycles, indicating that CDP can be regenerated and reused. This, together with its high adsorption capacity, makes CDP a potential adsorbent for the removal of MV in wastewater.

Functional effects of ants in rainforest canopies depend on difficult to characterize ant diets. In Bornean dipterocarp forests, certain diurnal, arboreal, territorial, and ecologically dominant 'COCY' ant species (Colobopsis cylindrica clade) grazed epiphytic biofilms on adaxial leaf surfaces, as well as on tree trunks and branches. Microscopic examination of worker buccal pellets revealed numerous (mainly ascomycete) fungal spores, together with insect appendages and cuticle. Direct observations, video-imaging, and d 15 N isotope data rule out feeding by predation, but isotopes cannot separate fungi from plant and insect exudates as principal nitrogen sources. Lipid-rich products, extracted from pellets in situ, are hypothesized sources of essential sterols. Also present in pellets were colorful mandibular gland (MG) compounds unique to this ant clade and deployed, as a derived character state, in suicidal defense of foraging territories. Mildly antimicrobial and highly adhesive MG products also occur basally in the clade and may have first evolved for roles in microbial sterilization and food-gathering and processing. Proteomic studies of YG COCY ants detected 2% proteins in hypertrophied, product-filled MG reservoirs, but SDS-PAGE qualitative analysis revealed mostly low-molecular mass proteins and peptides (8-15 kDa), too small for enzymes but consistent with membrane-binding proteins and/or antimicrobial peptides. Breakdown of chitin and chitosan in pellets may occur with enzymes derived from molting fluids in insect cuticle (proteases and chitinases) and/or fungi and bacteria. To the extent that COCY workers collect and consume pathogenic and/or beneficial phyllosphere microbes, ant effects on plants may be mediated by these activities.Abstract in Malay is available with online material.

Cempedak durian peel (CDP) was used to remove Brilliant Green (BG) dye from aqueous solution. The adsorption of BG onto CDP was studied as functions of contact time, pH, temperature, ionic strength and initial concentration. In order to understand the adsorption process and its mechanisms, adsorption isotherm and kinetics models were used. The experiments were done under optimized 2-h contact time and ambient pH. Adsorption study showed that the Langmuir model best fitted with experimental data, and the maximum adsorption capacity was determined as 0.203 mmol g(-1) (97.995 mg g(-1)). Adsorption kinetics followed the pseudo 2nd order model, and intraparticle diffusion is involved but not as the rate-limiting step while Boyd model suggests that film diffusion might be in control of the adsorption process. Fourier transform infrared (FTIR) analysis showed that OH, C=O, C=C and NH functional groups might be involved in the adsorption of BG onto CDP. Thermodynamic study suggested that the adsorption of BG onto CDP is endothermic with ΔH (o) value of 12 kJ mol(-1) and adsorption is feasible. Regeneration of CDP's ability to remove BG was also studied using three different washing solutions. NaOH (0.1 M) was not only sufficient to be used to regenerate CDP's ability to remove BG but also improved its adsorption capability.

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