scholarly journals Anaerobic digestion of kitchen waste generated from Atomic Energy Research Establishment (AERE) cafeteria for lactic acid production

2020 ◽  
Vol 5 (3) ◽  
pp. 88-99
Author(s):  
Syful Islam ◽  
Tabassum Mumtaz ◽  
Foysal Hossen

Due to accelerated economic growth and increased food production, per capita rate of waste generation is also increasing in Bangladesh. Being the ninth most populous and twelfth most densely populated country in the world, Bangladesh will face serious crisis in both food scarcity as well as food loss if food wastage problem is not addressed. At household level, 5.5 percent food is wasted on daily basis. Due to its large volume, the disposal of food waste will be a major problem. Production of Organic acid from kitchen waste via anaerobic digestion can eliminate both waste pollution problem and high cost production of organic acid. Such organic acid can be used in food and beverages, cosmetics, and detergent industries. The present study was undertaken to convert kitchen waste generated from cafeteria of Atomic Energy Research Establishment (AERE), Savar, Dhaka into lactic acid using natural microflora. The number of indigenous microflora in kitchen waste were found to be 1.25×107 cfu/mL and pH range of 5.0-6.0. The ratio of rice, meat and vegetables in the kitchen waste was found to be 3:1:1. Kitchen waste was found to contain approximately 19.03% protein, 3.2% fat and 1.5% ash. Anaerobic digestion was carried out in shake flasks at various initial pH (5.0, 6.0 and 7.0) and different temperature (30℃, 37℃ and 45℃) for 96 hours. Highest lactic acid from Kitchen waste was produced (24.00 g/L) at 24 h at initially adjusted pH-7.0. An attempt to recover Lactic acid from fermented broth was conducted using rotary evaporation at 100℃ and at (60-65) cm. Hg vac. The results indicated that, the volume of food waste can be greatly reduced and can be converted into value-added products such as lactic acid via anaerobic fermentation. Asian Australas. J. Biosci. Biotechnol. 2020, 5 (3), 88-99

2021 ◽  
Vol 323 ◽  
pp. 124618
Author(s):  
Zengshuai Zhang ◽  
Panagiotis Tsapekos ◽  
Merlin Alvarado-Morales ◽  
Irini Angelidaki

2020 ◽  
Vol 12 (12) ◽  
pp. 5222 ◽  
Author(s):  
A. Sinan Akturk ◽  
Goksel N. Demirer

The positive effects of conductive material supplementation on anaerobic digestion have been mainly investigated for single synthetic substrates, while its significance for real and complex organic wastes such as food waste has not been sufficiently investigated. This study investigated the effect of conductive material (biochar and magnetite) and trace metal supplementation on the anaerobic digestion of food waste by means of biochemical methane potential assays. The results indicated that the supplementation of biochar and trace metals improved both total biogas production and methane yields. A biochar dose of 2.0 and 5.0 g/L resulted in 11.2 ± 6.5 and 27.3 ± 9.5% increase in biogas and 8.3 ± 6.8 and 33.2 ± 2.8% increase in methane yield, respectively. Moreover, the same reactors demonstrated high food waste stabilization performance of over 80% chemical oxygen demand removal efficiency. These results indicate that biochar supplementation leads to more enhanced anaerobic digestion operation that could be through increased surface area for microbial growth and/or direct interspecies electron transfer mechanism. In turn, food waste will not only be stabilized but also valorized by anaerobic digestion at higher efficiencies that support sustainable waste management through both environmentally safe disposal and value-added generation.


2019 ◽  
Vol 687 ◽  
pp. 341-347 ◽  
Author(s):  
Quyen Ngoc Minh Tran ◽  
Hiroshi Mimoto ◽  
Mitsuhiko Koyama ◽  
Kiyohiko Nakasaki

2010 ◽  
Vol 113-116 ◽  
pp. 1080-1083 ◽  
Author(s):  
Ying Ying Liu ◽  
Qun Hui Wang ◽  
Li Wei Chen ◽  
Xiao Qiang Wang ◽  
Juan Wang

In order to reduce the costs of production and increase the lactic acid yields, this research adopts Bacillus subtilis to substitute enzymes. The method used in the study is two-phase fermentation - inoculate Bacillus subtilis to food waste to produce sugar, and then inoculate Lactobacillus to food waste to yield lactic acid. 87.22 g l–1 of total sugar can be obtained from non-autoclaved food waste in 30 h of saccharification at 40 centigrade. After two-phase fermentation, the optimal lactic acid concentration was 50.77g/L. The results indicate that two-phase fermentation is better than synchronous saccharification fermentation.


1973 ◽  
Vol 53 (1) ◽  
pp. 81-85 ◽  
Author(s):  
T. R. DAVIDSON ◽  
K. R. STEVENSON ◽  
J. BUCHANAN-SMITH

Early bloom alfalfa (Medicago sativa cult Saranac), at 22.5% dry matter, was harvested with a forage harvester. Formic acid (85% solution) and formalin (37.5% solution) and various combinations of mixtures were applied to the forage on a fresh weight basis at rates of 0.33, 0.50, and 0.66%. A sample of the treated material was ensiled in test tube silos fitted with fermentation locks. At various time intervals, analyses were made to follow the patterns of organic acid production. In untreated silage, the pH dropped to 4.3 with high lactic acid production, but after 39 days, the pH began to rise as lactic acid was degraded by Clostridia. Formic acid at 0.33 and 0.50% delayed but did not prevent either lactic acid production or subsequent degradation. Formic acid (0.66%) and all rates of formalin depressed lactic acid production. The production of butyric, isobutyric, and isovaleric acids was depressed to low levels only at the 0.66% rate of treatments. Formic acid was more effective than formalin in depressing volatile fatty acids. The formic–formalin mixtures gave results intermediate to separate applications of formic acid and formalin for all parameters analyzed.


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