Effect of pre-treatment palm oil mill effluent POME on biohydrogen production by local isolate clostridium butyricum

Palm oil mill effluent (POME) contains approximately 6% fiber. The effectiveness of pre-treatment on POME can serve a very good feedstock for hydrogen production in fermentation process. In this research, the effectiveness of pre-treatment methods on POME treated using acid and base were analysed based total carbohydrate and reducing sugar content. By using 1M NaOH with heat treatment, 26.12% carbon source converted to reducing sugar while by using 1M H2SO4 with heat treatment, over 32.09% carbon source converted to reducing sugar. The highest increment of total carbohydrate where from acid-heat treatment with 26.1% increment from initial concentration. At the initial pH (5.5) with fermentation temperature 37 oC, the highest hydrogen production rate given by acid-heat treatment was 0.5mL H2/mL POME. Different for initial pH 7.0 with the same temperature, the highest hydrogen produced rate was given by base-heat treatment with 0.59 mL H2/mL POME. The production of hydrogen in 2L bioreactor given much higher hydrogen production compare to production in serum bottle. This fermentation was run in batch mode with initial pH 7 and control at 5.5. The maximum hydrogen produce was 4304 mL H2/ L POME from acid-heat treatment

Isolation and screening of potential bacteria with biofilm formation ability and their hydrolytic enzymes for enhanced biogas production

Biofilm mediated anaerobic digestion of POME are to be studied to produce biogas. Out of 120 strains isolated from palm oil mill effluent (POME), palm kernel cake (PKC), and food waste compost, only 13 strains showed biofilm producing ability with significant amount at OD595nm (>0.01). In hydrolytic enzyme assay test, which are amylolytic enzyme assay, cellulolytic enzyme assay, lipolytic enzyme assay, and proteolytic enzyme assay all strains does not secrete protease enzyme, and strain number 1C and 23 does not secrete any hydrolytic enzymes. Strain number 23C and 30C shows positive result for cellulase, amylase and lipase enzymes to be tested as single strain bacteria for prospect research on producing biogas while other strains will be treated as mixed culture in future research

Interaction effect of co-digestion sewage sludge and food waste for production of biogas

Increasing population, urbanization and industrial activities have increased the amount of solid waste worldwide. Food waste (FW) and sewage sludge (SS) are some of the solid wastes. Co-digesting of both substrates may improve process stabilization to increase biogas production and overcome the nutrients imbalance. Thus, anaerobic co-digestion has been recognized as a technology that could provide a clean renewable energy source and help reducing the landfill problem. In this study, the interaction between FW and SS as co-substrates in anaerobic digestion was studied under mesophilic temperature 36C (± 0.5). The experiments were conducted using five batch reactors with different ratios of substrates. There are four different analyses used to identify the characteristics of FW and SS, which are pH, reducing sugar (RS), total solid (TS), and total carbohydrate (TC). Water displacement method was used to record biogas yield. The experimental results showed that the highest biogas yield was from the composition of 50:50 (FW: SS) with a biogas volume of 1150.14 mL, while the least was the composition of 0:100 (FW: SS) with 170.47 mL biogas produced. The results for substrate degradation showed that the composition of 100:0 (FW: SS) has the highest percentage degradation for reducing sugar with the percentage of 56%, while the minimum was 0:100 (FW: SS) with a percentage of 35%. Besides, for TC, the highest percentage of degradation was the composition 50:50 (FW: SS) with 84%, and the least was 0:100 (FW: SS) with 44%. This study proves that using FW and SS enhanced biogas production as well as reducing the current issues of waste disposal

Isolation and screening of bacteria with biofilm formation ability and characterization with hydrolytic enzyme production for enhanced biogas production

Aims: Biofilm is a complex structure that provides protection towards the bacteria within the barrier. Enhanced biogas production from Palm Oil Mill Effluent (POME) can be achieved by applying biofilm based anaerobic digestion system. Methodology and results: Bacteria that produces biofilm were isolated and tested on its hydrolytic enzyme secretion. The biofilm produced were also characterized. Out of 120 strains isolated from POME, PKC and food waste compost, only 33 strains were producing biofilm and only 11 of them exhibited significant amount of biofilm produced at optical density of wavelength 595 nm (>0.01). In hydrolysis enzyme assay test, all strains were not able to secrete protease enzyme. The biofilms were extracted and characterized to show similar characteristic for all strains. Strain numbers of 11, 9C, 23C and 30C showed positive result for cellulase, amylase and lipase enzymes, to be tested as single strain bacteria and also mixed with other isolated bacterium for prospect research on effective hydrolysis towards enhanced biogas production. The composition of biofilms from different bacteria mixture also similar under the same incubation condition. Conclusion, significance and impact of study: Bacteria producing biofilm are very limited and does not secrete the same hydrolytic enzymes. Utilization of these bacteria may eliminate the problem of microbial instability in a system

Synergistic enhancement of biohydrogen production by supplementing with green synthesized magnetic iron nanoparticles using thermophilic mixed bacteria culture

The production of biohydrogen can be improved by focusing on the nutrients needed by fermentative bacteria like iron. Iron reacts with the [Fe-Fe]-hydrogenase enzyme within the mixed bacteria culture for optimum hydrogen release. Iron nanoparticles (NPs) are attractive due to its unique properties and high reactivity. It can be produced through green synthesis, a more eco-friendly and relatively lower cost process, by using iron salt as precursor and green coconut shell extracted by deep eutectic solvent (DES) as reducing agent. The coconut shell extract consists of phytochemicals that help in producing poly�disperse magnetic iron oxide nanoparticles at ~75 nm in size. The addition of optimum concentration of 200 mg Fe/L magnetic iron NPs resulted in the maximum cumulative hydrogen production, glucose utilization and hydrogen yield of 101.33 mL, 9.12 g/L and 0.79 mol H2/mol glucose respectively. Furthermore, the kinetic analysis on Gompertz model using the optimum magnetic iron NPs concentration showed that the hydrogen production potential (P) and hydrogen production rate (Rm) increased to 50.69 mL and 3.30 mL/h respectively and the lag phase time reduced about 7.12 h as compared with the control experiment (0 mg Fe/L). These results indicated the positive effects of magnetic iron NPs supplementation on fermentative biohydrogen production of mixed bacteria culture and proved the feasibility of adding the magnetic iron NPs as the micronutrient for enhancement of such hydrogen production system

Utilization of organic waste

Waste is unwanted or unusable materials, any substance which is discarded after primary use, or is worthless, defective and of no use. Many different types of waste are generated, including municipal solid waste, agricultural and animal waste, medical waste, radioactive waste, hazardous waste, industrial non-hazardous waste, construction and demolition debris, extraction and mining waste, oil and gas production waste, fossil fuel combustion waste, etc. In general, it is divided into inorganic and organic waste

Environmental awareness and education: a key approach to solid waste management (swm) - a case study of Klang valley

Solid waste management has been a worldwide issue which most countries are finding the best ways to deal with it. Improper waste management poses a threat to the health of individuals and the environment. The general problem is the perception of the local communities towards solid waste management. It is important to analyze the current level of awareness towards solid waste management to be serve as reference for policy making or education purposes. Thus, this research seeks to analyze the level of awareness towards solid waste management in Klang Valley, which is defined into three aspects knowledge, attitude, and behavior. This research is described as a descriptive survey that is done on Klang Valley communities. The statistical analysis used in this research are descriptive, frequency and Principal Component Analysis using Statistical Packages for Social Science (SPSS) Software for statistical analysis. Generally, regarding solid waste management in Klang Valley, the respondents are highly knowledgeable except for e- waste, however the calculated mean for the attitude is 1.85 and 2.66 for behavior which indicates that their level of attitude and behavior towards solid waste management is low and moderate. Principal component analysis shows that there are three and four principal components for attitude and behavior sections respectively which greatly impact on the respondent’s attitude and behavior towards solid waste management. To conclude, promotional and encouragement on proper solid waste management has to be conduct frequently by the public or authorities

Anaerobic co-digestion of sewage sludge and food waste as a promising alternative for waste management and energy production

Biogas is an economical and environmentally friendly renewable energy which can be produced by anaerobic digestion (AD). This biochemical method converts organic compounds (mainly from wastes) into a sustainable source of energy. Anaerobic co-digestion (AcoD) is a method combining more than one substrate to resolve the difficulties faced in a single substrate AD system. Solid wastes increases as the population increase so do the urbanization and industrial industries. Food waste and sewage sludge are examples of one of the solid wastes. Co-digesting of both substrates may improve process stabilization to increase biogas production and overcome the nutrients imbalance. Thus, anaerobic co-digestion has been recognized as a technology that could provide a clean renewable energy source and helps reduce the landfill problem. The objective of this paper is to investigate the recent achievements and perspectives on the interaction of co-digestion between food waste and sewage sludge to improve biogas production. This may provide valuable information on the optimization of combinations of substrates: food waste and sewage sludge and prediction of bioreactor performance

Optimization of food waste to sewage sludge ratio for anaerobic co-digestion process using Artificial Neural Network (ANN) and Genetic Algorithm (GA)

Food waste is a major global issue especially in developed countries. This is because of the abundance of food waste in landfills has contributed to the emission of greenhouse gas (GHG). Therefore, by using anaerobic co-digestion technology, food waste (FW) can be used as a substrate with sewage sludge (SS) to produce a valuable product such as methane gas. In order to find the optimal ratio of FW to SS as well as substrate-to-inoculum (SI) ratio for the highest methane production, the present study utilizes the Artificial Neural Network (ANN) and Genetic Algorithm (GA) model. This study is based on the secondary data sources from various research papers and articles. The digester operational parameters such as mixed substrate ratio and SI ratio were considered. The optimal feedstock ratio was evaluated based on its biochemical methane potential (BMP). The performance of the ANN model was verified to be effective in predicting the methane production accurately with a desirable R2-value of 0.9838 and 0.9976. The trained ANN model was coupled with GA to optimize the methane production and to find the optimal feedstock ratio. The result of optimal mixed substrates ratio of FW:SS and SI ratio are similar which is 50:50 with the highest methane production of 454.4 mL CH4/kg volatile solids (VS). However, the comparison of BMP from different substrates ratio shows inconsistency on the optimal ratio. Hence, other parameters such as particle size and mixing rate should be considered