General answer to your question: aerobic process is faster, more efficient in turnover of wastes, but it consumes more energy, the loss of organic matter is higher.

According to my opinion you need to know quality of organic waste (carbon content, nitrogen content, phosphorus copntent, moisture content) which serves as a raw material and you need to know what should be the result of organic waste conversion, it means what would be the characteristic and parameters of fertilizer produced. When we know this basic information (what we have in the beginning and what we want to have at the end) then the answer to your question could be more precise.

Regards

Vit.  

Anaerobic digestate has N in ammonia form, which is easier for the plants to absorb, and more colloids, which improve the soil's texture. One of my customers, after 5 years applying anaerobic digestate, observed a consistent saving in the irrigation costs of corn, because the soil holds water better.

Anaerobic process is better to convert organic waste into fertiliser. This is cast effective and well used technique  in India.

Shivendra Shravan Patil

to decided which one is best option considering what you what from the process first. if you want to shorten period it is best option is aerobic, if you want energy recovery with fertilizer anaerobic is better. please considering  factor associated with the fertilizer recovery process

Anaerobic digestion is better especially for soluble lignin. Perhaps you can harvest biogas from anaerobic digestion

In general terms: fertilizer obtained from aerobic treatment (i.e. composting) requires more water and energy; and when obtaining fertilizer from A.D. the general energy balance process is positive due to methane production (when is utilized as an energy source). However it is really important to consider always C:N ratios, and in case of digestate from A.D. processed into fertilizer; consider the material used as feedstock to the digester; since local and national regulations for applying digestate into soils for agriculture, forests or areas with direct contact with human may vary. Finally, using the life cycle assesment tool; anaerobic process tends to be preferred than aerobic processes for organic waste treatment.

Regards 

First it may depend your needs.

If you wish also to destroy enteric microorganisms then aerobic process is better. This is incorrect in many papers. BUT enteric microorganisms are basically anaerobic and as is the intestinal channel.   

If a) you have plenty of organic waste and b) this waste is similar AND c) you have ability to store and use methane and d) you do not have any real winter, anaerobic process is good - possible better. But if there is only a little bit waste and  its quality varies, then aerobic process can be better.     

Anaerobic process preserves nitrogen: organic nitrogen is converted to ammonium. In the aerobic organic nitrogen is also converted to ammonium but this is emitted as ammonia during composting. Another big difference is that the product is dried during composting (by the heat generated). The anaerobic products is still wet.

Ok,

Manure can be dry but is can also be slurry containing some 3-5 % dry matter. In Western countries this is usual. If you have this slurry at cold climate slurry can be covered by ice.  In this slurry anaerobic    process is very slow. Aerobic process can be started.  In aerobic process we loss some 10 % of nitrogen.  Aerated slurry has no smell so its spreading is more nice causing less discussions. Also its spreading is rather easy. Slurry is a fertilizer - not irrigation water. 

Dear Shivendra

According to me, it is necessary to follow different step:

1-study the physico-chemical characteristics to now organic fraction which can be converting to fertilizer

2- use anaerobic digestion processing technology

3- use Biological pretreatment includes both anaerobic and aerobic methods, as well as the addition of specific enzymes such as peptidase, carbohydrolase and lipase to the anaerobic digestion system .

Hoping it will be helpful.

Marius

I agree with those who advised you to go for anaerobic digestion. In addition to these privileges of saving nitrogen for crops benefit, you can also gain biogas which would add some value and reduce labor cost

This really depands. As Fidèle Suanon said, you will save Nitrogen and gain electricity and hear by CHP from biogas through anaerobic digestion,but you also have to treat digestate especial when it can not be used as compost or liquid fertilizer.  For aerobic composting need large field and will release large amount of odour, but the reduction rate are really high, and you will also gain compost if your material were good.

Anaerobic digestion gives high solids removal, better pathogens kill and more useful products than aerobic process. It gives biogas, bio hydrogen, and a better nutrient rich fertilizer. Moreover, anaerobic digestion produces energy while aerobic process requires energy for constant oxygen supply. It is low cost, needs less area as compared to aerobic process.  

Dear Shivendra Shravan Patil!

There is no "better" or "worse" between aerobic and anaerobic treatment!

I agree with the comment, first to characterise input materials (amount and compostition) and wanted "quality" of fertiliser (easy availability of nutrients or long lasting effects).

Input: the higher the water content (liquid, pasty), the higher easy available organic compounds, the more the waste fits for anaerobic digestion. These wastes show too less structure for aeration (composting), thus you will have to add structure stabile wastes (e.g. residues from tree or bush cutting - question: are structure stabile wastes available??).Dry wastes, woody wastes, lignin are better for aerobic digestion (wood, lignin will not be degraded under anaerobic conditions).

Quality of fertiliser: is there need for easy available nutrients (analog to mineral fertiluser) ==> anaerobic; but there is need for enough agricultural land nearby for application (nitrogen load may influence ground water)

or do you need a steady release of nutrients over long periods (but lower availability just after application). By humification (which is possible only by aerobic conditions) nurtients are fixed within the humus matrix, thus they are not soluable by water (losses into resp. pollution of groundwater is reduced!) but available for plants.  Additionally very stable organic matter is built up by humification, which leads to much more positive effects to soil quality than only addition of nutrients (soil properties, water holding capacity, aeration, microbial life, plant health increasing effects, ....).

Also the amount of wastes is to be taken into account: what is the projected size of the plant? Is there a local need for the total amount of produced energy (gas)? Is conversion into electric energy possible (additional costs for engines)?

About sanitisation I disagree to the comment above: by mesophilic anaerobic treatment elimination of pathogens can not be guaranteed! Thermophilic anaerobic treatment needs energ for heating the reactor. Aerobic microbes produce heat, which raises temperatures within the composting windrows up to 60-70 °C, which guarantees proper sanitisation.

Last but not least about nitrogen losses: If composting process is not managed proper, nitrogen losses (NH3) may occure (depends mainly on C/N-ratio, speed of degradation and pH-value). Optimising the processing for humification (not mineralisation) of organic matter reduces N losses.

Under anaerobic conditions NH4 will remain within the digestate, but may lead to losses during storage and during/after application (high solubility) of the fertiliser.

Kind regards

Erwin Binner

Aerobic gives amendement (compost)

Anaerobic gives organic-P fertilizers and mineral-like fertilizers (struvite, ammonia sulfate, etc), biostimulant (liquid fraction containing organic matter) and organic amendement (solid fraction).

I agree wit hthe comments of Dr. Binner. Heat is one factor but not the only one. Also high  redox potential and  aerobic competing microorganisms change the enviroment so that salmonella will be destroyed. We have work abouts this. 

Dear

aerobic is best method as per volume and treatment view. In Anaerobic the sludge formation and its treatment is costly.

Regards

AK Swarnakar