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Usage of conventional energy sources such as oil, coal, and natural gas as an energy source for development has led to many economic, environmental, social, and political impacts worldwide. Due to this, the world has redirected its policies and investments towards producing clean energy which is based on renewable resources such as biomass. Due to the limitation of biomass which is low-density value, high moisture contents at the production place and non-uniform sizes and shapes, biomass was considered difficult to be utilized efficiently. To overcome this, pellet fuels were used to increase the density of the biomass. Since the enormous quantity of crops is produced from nipa palm, this paper focuses on studying the pelletizing properties of different parts of nipa palm seeds through the determination of the drying behavior, calorific value determination, CHNS determination, and TGA analysis and mechanical strength on the nipa palm seed. Husk was observed to have the highest calorific value which was 3843.5 kcal/kg and mixture nipa palm seed has a calorific value of 4092.7 kcal/kg which is in range with the industrial pellets’ calorific value. Based on the CHNS analysis, carbon content was found to be the highest in the husk as compared to the other parts. It was observed that all parts of the nipa palm seed exhibit almost similar thermogravimetric (TG) curve but slightly different differential thermogravimetric (DTG) curve peaks with different maximum mass-loss rates. Finer size particles were observed to have better pellets’ performance in terms of its strength due to the higher surface area of the particle. Pellets formed from nipa palm seeds could be used to form pellet fuels given the fact that they have high calorific values and almost similar compositions with the industrial pellets.

Resolution of industrial waste as thermal source is an effective way to transform the unwanted scheduled waste into renewable energy. Plant residues also contributed to enhance its utilization and considered a reliable resource for energy uses. Both sectors of feedstock are aimed to produce significant amount of thermal energy through combustion. Ash deposition behaviors of biomass fuel from industrial sludge and agricultural waste have been analyzed. Sludge and effluent were carefully taken from petroleum crude processing plant (PGB) and palm oil mill (POME), respectively. Rice husk and kenaf were obtained from local neighborhoods farm. The effective utilization of potential biofuel is evaluated based on its ash content, chemical composition and its ash slagging and fouling tendency. PGB and POME were evaluated to have energy content about 21.35 MJ/kg and 15.238 MJ/kg respectively. While kenaf and rice husk each has 16.14 MJ/kg and 15.19 MJ/kg, respectively. Ash content of PGB sludge was around 30.0% where POME sludge was about 38.0%. Kenaf showed a better biomass type as the ash content was only 2% ash, whereas rice husk ash content was 11%. To illustrate the realistic combustion condition under different temperature, the effect of ashing temperatures that are 525°C, 575°C and 625°C to the ash deposition characteristics is also examined. This variation of ashing temperature will also deflect the chemical composition especially the heavy metal element in the sludge ash. Furthermore, the physical ash deposition and deformation characteristics are observed by ash fusion test. Conclusively, PGB, POME, rice husk and kenaf biomass are feasible to produce sufficient thermal energy as well as stable at high temperature with their distinct chemical composition, but their individual range ashing temperature may deficient the thermal process differently.

A fibrous boron chelator containing glycidol moiety (PE/PP-g-PVAm-G) was prepared by radiation induced grafting of N-vinylformamide (NVF) onto polyethylene/polypropylene (PE/PP) non-woven sheet followed by hydrolysis and immobilization of glycidol moiety. The glycidol density was controlled by optimization of the reaction parameters using the Box-Behnken design of response surface methodology (RSM). The properties of the PE/PP-g-PVAm-G were evaluated using Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM) and energy dispersive x-ray (EDX) analysis, X-ray diffraction (XRD) and thermal gravimetric analysis (TGA). A maximum glycidol density yield of 5.0 mmol·g−1 was obtained with 11.8 vol%, 78.9 °C and 109.4 min for glycidol concentration, reaction temperature and time, respectively. The isotherms, kinetics, and thermodynamic behavior of boron adsorption on the optimized chelator were investigated. The boron adsorption was pH-dependent and attained a maximum adsorption capacity of 25.7 mg·g−1. The equilibrium isotherm proceeded by Redlich–Peterson model whereas the kinetics was best expressed by the pseudo-second-order equation. The thermodynamic analysis revealed that boron adsorption is endothermic and spontaneous. The fibrous chelator demonstrated high boron selectivity and strong resistance to foreign ions with uncompromised regeneration efficiency after five adsorption/desorption cycles. The PE/PP-g-PVAm-G chelator seems to be very promising for boron removal from aqueous media.

In this study, a facile method was developed to prepare fibrous boron-selective adsorbent through introduction of poly(vinylamine) (PVAm) onto polyethylene/polypropylene (PE/PP) non-woven sheet by radiation induced graft copolymerization (RIGC) of N-vinylformamide (NVF) followed by hydrolysis, and glycidol immobilisation. The dependence of the degree of grafting (DG) on the reaction parameters (absorbed dose, monomer concentration, temperature, and reaction time) was investigated to control the content of hydrolysed poly(N-vinylformamide) (PNVF) grafts. The properties of the adsorbent were evaluated by Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), Scanning electron microscope (SEM), X-ray diffraction (XRD), differential scanning calorimeter (DSC), and thermal gravimetric analyser (TGA). The boron adsorption from solution on the prepared adsorbent was investigated under various pHs, contact times, initial boron concentrations, adsorbent dosages, and adsorption/desorption cycles. The adsorbent with a DG of 120% showed an adsorption capacity of 21.4 mg-B/g-adsorbent at pH 7 with an appealing stability. The overall properties and adsorption behaviour suggest that RIGC is highly effective method for preparation of glycidol-containing fibrous adsorbent with highly attractive properties for boron removal from aqueous solutions.

An adsorbent containing glycidolized poly(vinylamine) ligand with a remarkably high boron selectivity was prepared by modification of fibrous polyethylene/polypropylene (PE/PP) nonwoven sheet by radiation induced grafting (RIG) of N-vinylformamide (NVF) followed by hydrolysis and subsequent functionalization with glycidol. The variation of the absorbed dose and monomer concentration was used to control the content of the grafted P(NVF). Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM) were used to verify the chemical and morphological changes accompanied the applied procedure and boron loading. The fibrous adsorbent with fully hydrolyzed poly(NVF) grafts of 120% exhibited a superior boron adsorption capacity of 21.4 mg/g compared to commercial and researched counterparts at pH 7.

Membrane fouling is a major drawback of almost all pressure-driven membrane processes that limit their widespread application. This study compares the biological and the hydraulic performances of polyvinylidene fluoride (PVDF) and polysulfone (PSF) membranes when used as external filtration for polishing of a rotating biological contactor (RBC) effluent and as an integrated part in a membrane rotating biological contactor (MRBC). MRBC is an upgrade of the conventional RBC, in which the disk rotations are used not only to provide biological aeration but also as an inherent mechanism for membrane fouling control. Results showed that high biological performances were achieved irrespective of the membrane materials. The steady-state permeabilities of the membranes in MRBC are higher than external filtration by 92.4% and 19.7% for the PVDF and PSF membrane respectively. In the MRBC, smaller membrane-to-disk gaps and high disk rotational speed improve permeability for both membranes reaching the values of 297 and 173 L/(m2 h bar) for PVDF and PSF membranes, respectively. Full-scale energy consumption projection results show that the MRBC consumes only one-fourth of the energy of a referenced membrane bioreactor. The PVDF membrane outperforms PSF membrane thanks to the effective fouling control that maximize the throughput of a lower intrinsic resistance of the PVDF membrane. It implies that apart from membrane material, other operational parameters can still be optimized to further enhance the MRBC performance.