ORGANIC WASTE DISPOSAL 1

[ED33]

Hi everybody,
According to my company policy, We have zero waste landfilled target. The most of the landfiled wastes are; organic waste and bio solid. There is no incineration plant to burn organic waste in my country. First I thought about compost. It takes more time. I need to learn What other peoples are doing for organic wastes (such as, food wastes, especially). Does anybody know any metod about organic waste disposal.
Many thanks

 

[TerraSouth]

Interesting question. I have heard of a Contractor in Arkansas that has a permit to land apply sludge from a wastewater pumping operation. I don't know the details.

Check into a land application permit from your state Environmental Department. They could perhaps at least get you pointed into the right direction.

I know the poultry industry has to contend with alot of chicken waste. The producers sell this waste to farmers who land apply the waste to their farm lands.

 

[dalcazar]

that's a hard question ED33

there are only 2 biological treatment alternatives to landfilling, composting or anaerobic treatment and it comes down to land costs pretty much. I did my thesis on the anaerobic co-digestion of waste secondary sludge and municipal solid wastes.

Anaerobic digestion produces more energy than is put into it if you can take advantage of it, and it reduces solids by up to 90%, half of which goes to methane which can be burnt for energy (the methane must normally be scrubbed of H2S which is expensive). Initial investment costs for anaerobic digestion are extremely high. Composting on the other hand produces no useful energy, but all you need is land and the machine to do it with. You have to weigh cost and availibility of land against initial costs, so if land is cheap in your area you should definately go with composting. if not then anaerobic digestion might be the way to go because composting requires a LOT of land.

I can give you more advice if you tell me what waste you are dealing with.

 

[ED33]

Many thanks for your valuable ideas Dalcazar,
I have been working about this subject since 4 months. I have reduced food waste which is produced at canteen from 80 ton/m to 50 ton/m by making source reduction and seperation of solid and liquid waste.
I know ,landfill is cheap choice but I don't do it.Because our target is zero landfilled waste. So I have to do compost or decompost (anaerobic digestion). After produce compost, I need to give it to some farmers for every month. It is not easy to do. Now, I have concentrated about anaerobic digstion. I found some companies from japan and Korean which They makes decompost machine. please see

http://www.fiss.net

web site. But I don't know their efficieny ? So I have a doubt. Do you know that ?
If You have further information please share me! Type of food waste; BREAD,POTATO,TOMATO,ONION,BEAN,BALD,VEAL,MUTTON,
FISH, BONE, MINCED BEAD, HARICOT BEAN, PEA, CUCUMBER
LETTUCE, PEPPER, AUBERGINE, RICE, SPAGHETTI, YOGHURT STEWED FRUIT, CORN ,BROCOLLI, MELON, W.MELON, PLUM, BERRY, ORANGE
DESERT, and table napkin, toilet paper and bio solid comes from biological waste water treatment plant.

 

[dalcazar]

ED33

I'm assuming you have 80 tons a month, and that the total solid waste weighs 50 tons a month after you have separated it.

Those decomposer bins at FISS look very small and not made for large scale use, also they look like automated composting bins and not anaerobic digesters.

You will have to take a sample of your combined waste to a lab and have it analyzed for Carbon:Nitrogen ratio, it has to be between 20:1 or 30:1 for the process to work well, either for composting or for anaerobic digestion, normally food wastes don't have enough carbon in them and an external source must be added, this is usually straw or grass clippings. From my own experience, getting a representative sample of a mix of all those ingredients is very difficult, I suggest you allow the lab to take care of that part of the operation. You will also want to know water content, total solids, volatile solids and suspended volatile solids.

Anaerobic digestion produces less solid waste, but this waste must be dried when it comes out, also the gas produced by the digestion process can have high levels of sulfhidric acid (H2S) which will corrode nearly anything, so reactor vessel must be stainless steel construction. The high amount of sugar in the waste will probably make it produce large amounts of gas, harnessing that gas can be expensive, especially if you want to burn it for energy since you may have to clean (scrub) it, there are small turbine generators that produce 30 kW of electricity which can run on the raw gas but they cost around 30,000 US dollars for a single unit. Again this will all depend on you gas composition.

Residence times for solids in an anaerobic digester run from around 25 to 60 days depending on your waste and the arrangement of the digester, so you have to plan on having something big enough to hold 50 tons, initial startup times are long (a few months) and the digesters usually produce a very strong leachate waste water which will have to be piped into your existing wastewater treatment facility.

Anaerobic digesters must be heated to above 28 degrees celsius to work well, prefferably to 37 degrees celsius for optimum efficiency, so factor in a boiler and a heating system. You can also work in a thermophyllic configuration where you run the reactor between 55 and 60 degrees celsius, you can reduce residence times in this way to as little as 10 days if the system works really well.

You can begin to see the investment getting bigger and bigger, take all this into account on your budget and composting may start to seem simpler and cheaper... and it is. In my thesis the economic report showed the system beginning to pay for itself after around 20 years, the initial investments were in the millions of dollars. but that was a very large project, for 200,00 people.

Have a look at that and tell me more about your project as well as ask me any questions as you have them, I'll keep answering you here when I can.

 

[cub3bead]

Even if completely digested or gasified some inorganic material will be left that will have to be landfilled. Granted the volume and mass of the material will be very small compared to the starting point, I don't see how you achieve the goal of zero landfill for the waste.

 

[dalcazar]

the digested sludge removed from the process is an even better soil ammender than compost if the process works right, it has to be dried but it should meet class A standards so it can be applied to any crop, it doesn't need to be landfilled, although you can landfill it. most landfills won't accept any kinds of sludges or charge you extra for their disposal.

 

[dicksewerrat]

Can you feed this to a herd of pigs? Looks like they would really like this. Or dry and pelletize this for fish food for a fish farm. You may be able to sell this stuff to the farmers instead of giving it away. Try a program that the farmer hauls it and you give it away. If the hogs like it you may be able to sell it later on.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[ED33]

Hi everybody
Thanks a lot for your valuable ideas.

 

[ED33]

Dicksewerrat,
I konw all pigs likes this waste. Unfortunately,
There is no pig farm in My country.(TURKEY) So It is not possible. Your second idea is interesting. Can You provide me detail info for this idea.
Many thanks

 

[bimr]

Feeding animal-contaminated matter to livestock (pigs) is a particularly bad idea. Have you ever heard of Mad Cow Disease?

Prevention of access to food waste by livestock is a key issue. Disposal of waste must consider potential access by both domestic and feral animals.

There are currently no prescribed methods for disposal of animal matter or animal-contaminated matter that must be followed.

However, some broad principles can be applied, either separately or in combination, to ensure safe disposal:

Use a licensed waste disposal contractor. This ensures the waste is collected and transported in a manner that keeps it contained and prevents it being exposed to animals. The waste is then disposed of in a licensed landfill site. If no contractor is available, food waste should be collected and transported in containers that prevent access to it by stock at all times.

Bury the material at sufficient depth to prevent access by livestock. Burial should occur immediately if the site is unfenced or unattended and/or, Dispose of the material at a dumpsite that is adequately fenced and secure from animal entry to the site.

Other options for disposal are possible. For example, composting is possible, but techniques and feasibility need more research. Although animal matter does require special attention for successful composting, animals must still be excluded from composting sites to avoid digging up of animal matter.

Since you do not want to landfill it, your only remaining option for disposal of food waste is to compost it. Bio-solids from biological wastewater treatment plant should kept separate and be land applied to a non-food crop.

 

[ED33]

Dalcazar,
Thank you for your ideas. I have also one question related with composting; How is the effect of biosolid (biological sludge comes from waste water treatment plant) to the composting? Is It possible to mix foods within biosolid?
What shold be the criterias ? What is the heavy metal effect to the compost ? If You participate your ideas, I will be very appreciated.
Many thanks

 

[dalcazar]

ED33

It is very possible to mix food with biosolids, in fact Waste Water Treatment Plant (WWTP) SECONDARY sludge is too low in carbon content to compost on it's own, so a high carbon additive like sawdust must be added. other alternatives are hay, wood chips or grass clippings, the smaller the surface area of each particle, the faster the process will go. I assume you are reffering to secondary waste sludge and not primary. Primary waste sludge is extremely fermentable and is near impossible to keep from stinking, it's also too high in pathogens to be composted for any practical use, anaerobic digestion is a must.

Mixing foodstuffs in with biosolids would work, however the biosolids will "dilute" the higher carbon content of the food and thus the carbon ratio may still be too low so this would have to be monitored and supplemented with an external source as I reffered to before. Of course your final carbon ratio will also depend on how much of each kind of waste you have available, you may be able to compost if your waste to biosolid ratio is around 80-20. Heavy metals will remain in place if they are present in the feedstocks, you will have to analyze your waste sludge and determine how much you have present in there, then compare it to your local legislation to see if it is land applicable.

bimr has a point that compost from WWTP biosolids should be kept away from food crops. you may choose to combine both and compost for application on non food crops, or you can separate them and compost for food crops in the case of your food waste. Composting both together can, in theory, produce a compost that is clean enough (microbiologically speaking) for food crops, in addition, some foods are safe when used with such a compost, while others are not. I wouldn't recommend food crop application as bimr said. In the end you must use your own judgement and design your operation protocol and mixes around the sites you will be applying the finished compost to.

Composting offers you the flexibility to change the operating parameters easily and suddenly without much effect, if you wish you can co-compost the waste or treat each stream separately on the same grounds with little increase in labor or effort depending on which composting method you use. It also allows you to quickly adapt to a changing disposal site. have you given any thoughts as to how you will perform the composting itself?

 

[bimr]

Dalcazar has made presented some good comments.

Some additional thoughts:

1. You will have no problems composting sanitary wastes. As Dalcazar stated, you will need to add a carbon additive source like sawdust or woodchips in order to compost biosolids from sanitary wastewater treatment. This will compound your waste disposal problem because now you will have a larger volume of material to dispose of. Disposal of the compost will be a problem if you do not have a place to put the compost. You should plan on disposal at a non-food crop application.

2. Be aware that composting will involve generation of odors that most people consider to be obnoxious and a nuisance. You need a large open area away from populated areas.

3. Foods waste will also compost without any problem.

4. You do not need to be concerned about heavy metals unless your facility is generating the heavy metals and adding the heavy metals to the waste stream.


2. Be aware that composting will involve generation of odors which most people consider to be obnoxious and a nuisance. You need a large open area away from populated areas.

3. Foods waste will also compost without any problem.

4. You do not need to be concerned about heavy metals unless your facility is generating the heavy metals and adding the heavy metals to the waste stream.

 

[dicksewerrat]

I would search the internet for fish farms in your country and fish food manufacturers. I just know that fish food is pelletized to make it easy to bag and sell.One in the US that comes to mind is Purina. they make all kinds of animal feeds in pellets. contact a few zoos in your locale.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com