Performance of Food Waste Feeding Pilot Plant Biodigester Operated with Identified Potential Substrate Properties

Anaerobic digestion has been proven as sustainable process technology for organic waste conversion into renewable bio-energy. This study was conducted to evaluate the performance of mono-digestion process for different types of food waste substrates using pilot scale anaerobic bio-digester (1200 L) in terms of biogas production and the chemical oxygen demand (COD) removal efficiency. The biochemical methane potential (BMP) test of rice waste (R), vegetable waste (VW) and coconut meat residue (CMR) were tested at initial volatile solid (VS) loading of 0.1631, 1.1690, 1.0059 g VS/L, respectively at fixed inoculum/substrate (I/S) ratio of 0.5. Further study conducted by using rice waste (R) in pilot plant anaerobic bio-digester (1200L) for 43 days to investigate the reactor performance in term of COD removal efficiency. Interestingly, inoculum used for this study performs very well and able to digest food waste. Results demonstrate that the maximum specific biogas yield (SBY) was observed from rice waste (R) at 0.0587 L/kg VS compared to other substrates. Specific biogas yield (SBY) of rice waste (R) was 16.01% and 11.92% higher than substrate vegetable waste (VW) and coconut meat residue (CMR) respectively. High COD removal efficiency of pilot plant bio-digester (up to 93 %) using rice waste (R) as sole substrate indicates a good performance of reactor in treating food waste. Conversion of food waste to biogas in pilot plant bio-digester is highly potential as one of the sustainable waste treatment technolog

Energy potential of oil palm Empty Fruit Bunch (EFB) fiber from subsequent cultivation of Volvariella volvacea (Bull.) singer

EFB and EFB-based mushroom compost (SMC) from Volvariella volvacea cultivation is a promising energy feedstock because it has adequate nutrient quality. The biochemical methane potential (BMP) and calorific value (CV) of this biomass are investigated. Other analyses such as proximate, compositional, and final analysis; thermogravimetric analysis (TGA); and Fourier transform infrared spectroscopy (FTIR) are also performed. The biomass samples consist of two types of EFB, namely fibers (F) and pellets (P) and SMC from the subsequent cultivation of Volvariella volvacea, with samples FS and PS from the first cultivation and FS2 and PS2 from the second cultivation. P produces the highest biological efficiency (BE) of 28% compared to 9.83% for F. Subsequent cultivation with FS and PS then produces only 2.9 and 6.83% of BE. A higher amount of methane is measured in samples P and PS2, while better biodegradability is observed in PS2 and FS2, suggesting that subsequent cultivation is a good pretreatment of the substrate for anaerobic digestion (AD). CV is highest in F (20.57 MJ/kg), followed by P (19.06 MJ/kg), which is comparable to commercial wood pellet. Samples F, FS, and FS2 have higher ash content, which is due to higher mineral content. The cellulose composition is reduced to almost 50% during cultivation due to fungal metabolism, which is also evidenced by FTIR analysis. TGA analysis revealed that EFB-based SMC exhibits higher weight loss during combustion compared to EFB, which reduces its thermal properties. SMC of EFB is a high potential biomethane feedstock, but not recommended as a fuel pellet

Turbid water treatment using deshelled carica papaya seed: Analysis via factorial design

Natural coagulants are proven to be a good alternative to conventional coagulants with the removal of various pollutants and are environmentally friendly. Despite its advantages, the least studies were carried out on local agro-wastes such as papaya seeds as natural coagulants concerning different operational factors. The study analyzes the main and interactions effect between the coagulant dosage, initial turbidity, and pH on deshelled Carica papaya seeds for turbid water treatment. A 2-level factorial design was used to investigate the main and interaction effects of the main operational factors, viz. coagulant dosage (50-200 mg/L), pH (3-7), and initial turbidity (100-500 NTU) on the turbidity removal of the synthetic turbid water. Based on individual performance, the results suggested that initial turbidity and pH are the most significant factors among the investigated operational factors. In combination, all interactions are significant, but the interaction between initial turbidity and pH is most significant, with 97.2% turbidity removal. Upon application of Carica papaya seed as a natural coagulant in water and wastewater treatment, these operating variables and their interactions are best to be considered

Energy Potential of Oil Palm Empty Fruit Bunch (EFB) Fiber from Subsequent Cultivation of Volvariella volvacea (Bull.) Singer

EFB and EFB-based mushroom compost (SMC) from Volvariella volvacea cultivation is a promising energy feedstock because it has adequate nutrient quality. The biochemical methane potential (BMP) and calorific value (CV) of this biomass are investigated. Other analyses such as proximate, compositional, and final analysis; thermogravimetric analysis (TGA); and Fourier transform infrared spectroscopy (FTIR) are also performed. The biomass samples consist of two types of EFB, namely fibers (F) and pellets (P) and SMC from the subsequent cultivation of Volvariella volvacea, with samples FS and PS from the first cultivation and FS2 and PS2 from the second cultivation. P produces the highest biological efficiency (BE) of 28% compared to 9.83% for F. Subsequent cultivation with FS and PS then produces only 2.9 and 6.83% of BE. A higher amount of methane is measured in samples P and PS2, while better biodegradability is observed in PS2 and FS2, suggesting that subsequent cultivation is a good pretreatment of the substrate for anaerobic digestion (AD). CV is highest in F (20.57 MJ/kg), followed by P (19.06 MJ/kg), which is comparable to commercial wood pellet. Samples F, FS, and FS2 have higher ash content, which is due to higher mineral content. The cellulose composition is reduced to almost 50% during cultivation due to fungal metabolism, which is also evidenced by FTIR analysis. TGA analysis revealed that EFB-based SMC exhibits higher weight loss during combustion compared to EFB, which reduces its thermal properties. SMC of EFB is a high potential biomethane feedstock, but not recommended as a fuel pellet

Bioconversion of oil palm frond to reducing sugar in solid state fermentation by applying water-fed strategy

Tones of Oil Palm Frond (OPF) waste from oil palm industries may affects the environment when released without proper treatment. Conversion of oil palm frond fiber into reducing sugar in the Solid State Fermentation (SSF) using Aspergillus fumigatus culture provide alternative for usage of these biomass. In this study, effect of the particle size of oil palm frond fiber and moisture content to the production of reducing sugar in SSF were investigated. Two particle size of OPF used are 100 and 250 μm while moiture level was set at 60, 70 and 80% (w/v). The fermentation process was carried out for 10 days. Effect of moisture was further analyzed by applying water-fed strategy. All fermentation using water-fed strategy yielded higher production of sugar than compared to others. Pmax of 4.446 g L-1 was achieved at 70% moisture level using 250 μm OPF while maximum Yp/s achieved was 0.442 (g g-1) in 80% moisture level using 250 μm OPF. Statistical analysis showed both particle size of oil palm frond fiber, 100 and 250 μm has no significant different towards production of reducing sugar in SSF by Aspergillus fumigatus. Statistically, moisture content of fiber does not significantly affect the production of reducing sugar but using water-fed strategy does gives significant difference. Sufficient moisture in SSF had increased the efficiency of fungus enzymatic system due to water holding capacity of substrate improved. Analysis two-way ANOVA suggest that presence of water fed has significant different towards production of reducing sugar in SSF and result in higher production of reducing sugar

Optimisation of a modified submerged bed biofilm reactor for biological oleochemical wastewater treatment

Oleochemicals industry effluence mainly contains a high chemical oxygen demand (COD) in a range of 6000–20,000 ppm. An effective biological wastewater treatment process must be carried out before wastewater is discharged into the environment. In this study, a submerged bed biofilm reactor (SBBR) was adapted to the biological oleochemical wastewater treatment plant observed in the present study. The effect of wastewater flow rate (100–300 mL/min), Cosmoball® percentage in the SBBR system (25–75%), and percentage of activated sludge (0–50%) were investigated in terms of COD reduction. The Box-Behnken design was used for response surface methodology (RSM) and to create a set of 18 experimental runs, which was needed for optimising the biological oleochemical wastewater treatment. A quadratic polynomial model with estimated coefficients was developed to describe COD reduction patterns. The analysis of variance (ANOVA) shows that the wastewater flow rate was the most effective factor in reducing COD, followed by activated sludge percentage and Cosmoball® carrier percentage. Under the optimum conditions (i.e., a wastewater flow rate of 103.25 mL/min a Cosmoball® carrier percentage of 71.94%, and an activated sludge percentage of 40.50%) a COD reduction of 98% was achieved. Thus, under optimum conditions, as suggested by the BBD, SBBR systems can be used as a viable means of biological wastewater treatment in the oleochemicals industry