vermicomposting and biogas

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Vermicompostin g And Biogas PRESENTED BY : Sheama Farheen Savanur

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Vermicomposting And Biogas

PRESENTED BY : Sheama Farheen Savanur

What is Vermicomposting?

Vermicomposting is essentially the consumption of organic material by earthworms. This speeds up the process of decomposition and provides a nutrient-rich end product, called vermicompost, in the form of ‘worm castings’. It is sustainable fertilizer giving more than 10-15% more crop yield besides crop improvement.

The most common species of earthworms which have consistently been used for commercial composting or worm farming, due to their relatively high tolerance of environmental variations are Eisenia andrie. E. foetida, Dravida willsii, Lumbricus rebellus and many others. The earthworms secrete a casting rich in Ca, Mg, K, and available P. Earthworms make tunnels & mix soil. Thus they aerate the soil which promote the growth of bacteria and actinomycetes. Consequently microbial activity of soil is increased due to increase in enzymatic and biological activity of earthworms

Process of vermicompostingVermicomposting can be done in pits or concrete tanks. A pit of 2X1x1 m is dug under shade to prevent the entry of water during rain. Wooden bricks are spread on the bottom of the

pit followed by coarse sand to facilitate drainage. It is covered by a layer of loamy soil which is moistened and inoculated by earthworms. It is covered by small lumps of fresh or dry cattle dung followed by a layer of hay or dry leaves or agro wastes. For the next 20-25 days water is sprinkled over it to keep the entire set up moist. Until the pit is full dry and green leaves are put into the pit each week. Vermicompost is ready after

40-45 days. Vermicompost appears spongy, soft and dark brown with sweet smelling. It is then harvested and kept in

dark. It is sieved and packed in polythene bags to retain 20% moisture.

Construction of Vermicompost pit

Advantages Of Vermicomposting• Improves soil’s physical

structure• Enhances germination, plant

growth, and crop yield• Improves root growth and

structure• Enriches soil with micro-

organisms • Production

reduces greenhouse gas emissions such as methane and nitric oxide

BIOGAS

What is BIOGAS ?•Biogas is a environment friendly fuel that can be obtained by anaerobic digestion of animal residues and domestic and farm wastes, abundantly available in the countryside.•Biogas is an important renewable energy resource for rural areas in India •Biogas generally comprise of 55-65 % methane, 35-45 % carbon dioxide, 0.5-1.0 % hydrogen sulfide and traces of water vapor. •Average calorific value of biogas is 20 MJ/m 3 (4713 kcal/m 3 ).

FEEDSTOCK MATERIALS :Cattle dung is most potent for biogas production. Besides this agricultural residue, dumped wheat grains, bagasse are also proved a good source for biogas production.

BIOGAS PRODUCTION:•The anaerobic digestion is carried out in an air tight cylindrical tank which is called a digester. It is made up of concrete bricks or cement.•It has a side opening (charge pit) into which organic materials for digestion are incorporated.•There lies a container above the digester to collect the gas•Anaerobic digestion is completed in 3 steps as follows:-

1: Solubilisation: It is the initial stage when feedstock is solubilised by water and enzyme. The feedstock is dissolved in water to make slurry. The complex polymers are hydrolyzed into organic acid alcohols by hydrolytic fermentative methanogenic bacteria which are mostly anaerobes. 2: Acidogenesis: In this 2nd stage facultative anaerobic bacteria & H2 producing acidogenic bacteria convert the simple organic matter by oxidizing or reducing into acetate. Another group of bacteria converts acetate via acetogenic hydrogenation

3.Methanogenesis: This is the last stage of anaerobic digestion where acetate and H2 &co2 are converted by methane producing bacteria into CH4and co2 and water. Different species of methanogens are involved here. All bacteria require H2 & formate for growth production. Thus methanogens are either autotrophs or utilize formate, acetate.The primary reaction is CO + H2O CO2 + H2

The secondary reaction is CO2 +4H2 CH4 + 2H2OOther reactions 4CH3OH 3CH4+ CO2 +2H20 4HCOOH CH4+3CO2+ 2H2O

USES OF BIOGAS•Provides a non-polluting and renewable source of energy.•Efficient way of energy conversion (saves fuel wood).•The technology is cheaper and much simpler than those for other bio-fuels, and it is ideal for small scale application.•Biogas can also be used for the simultaneous heating, cooling and power generation. •Biogas plants significantly lower the greenhouse effects on the earth’s atmosphere. The plants lower methane emissions by entrapping the harmful gas and using it as fuel.•Produces enriched organic manure, which can supplement or even replace chemical fertilizers

Thank you