09 December 2018

What is sewage sludge? Sewage Sludge Meaning? What are biosolids?

The Meaning of "Sewage Sludge"

Sewage sludge is the remaining, semi-solid material that is left over after the cleaned-up water is released from a sewage treatment works. An additional word for it is biosolids.

It is the strong material which settles out from municipal or commercial wastewater, when the nasty sewage is de-gritted and also held in huge tanks for between 1 hr to 1.5 hours.

On arrival at a sewage functions (called "Wastewater Treatment Works", by Utility Companies) fresh sewage "wastewater" flows first right into a grit chamber.

This is a long slim tank that is developed to decrease the flow to make sure that solids, such as sand, and grit, plus things like coffee grounds, as well as eggshells will certainly drop to the bottom and be taken out of the water.

It then moves right into a "main (primary) settling tank".

In the main negotiation tank, approximately 50% of the suspended strong matter will certainly settle out in an hour as well as a fifty percent, in which time (typically) the sewer-water remains in the tank.

The water overflows with dams externally, and takes place for further cleansing (treatment).

What continues to be in the "primary settling tank" is a collection of solids, called raw sewage sludge or primary solids.

Image features the "What is Sewage Sludge" web page.

It is stated to be "fresh" at the beginning, yet soon the liquified air is used up as well as anaerobic procedures (disintegration or decomposing without air (oxygen)) become energetic.

This sludge would begin to rot (ending up being putrescent), quickly once anaerobic bacteria take control of, and produce an undesirable odor.

So, it is eliminated from the "main settlement tank" (additionally called a sedimentation tank), before this takes place.

Generally, the fresh sewer sludge is constantly removed from the tank, utilizing mechanical scrapes.

It is handed down in a variety of ways, for additional treatment, and also disposal.

Instances of the ways further treatment is attained are:

- Activated Sludge Aeration (Extended Aeration).
- Imhoff Tanks, and also
- Upflow Anaerobic Sludge Blanket (UASB) Reactors.

Imhoff containers operate in the lack of air (oxygen), and also give a type of anaerobic digestion treatment.

Imhoff tanks are used infrequently now, as the food digestion procedure at the reduced temperatures of typical (unheated) sewers, is rather slow.

This means very large as well as "pricey to build" tanks.

UASBs are an additional technique which uses a combination of aerobic and anaerobic treatment areas.

Aeration (Extended Aeration) is what happens in a lot of sewer jobs, and also oygenation itself causes yet more sewer sludge (Return Activated Sludge - RAS) to be generated.

Currently, in conclusion by summarizing this video. You asked, "What is SEWAGE SLUDGE"?

We answered by stating: Sewage sludge is the basic term for all the sludges created at a sewer functions, by all the above procedures.

Click the link below to find out much more:

This discussion contains pictures that were made use of under a Creative Commons License. Go here to see the complete listing of pictures and attributions:


View this video clip on the YouTube website at:

19 November 2018

Advantages of Biogas - The Developing Nation Benefits of Anaerobic Digestion

The Most Important Advantages of Biogas

Arguably, the most important benefit of the biogas produced through the anaerobic digestion process, is energy generation. The most obvious benefit of anaerobic digestion is the production of methane rich biogas which offers a renewable alternative to the consumption of fossil fuels.

Beyond that the biogas advantage is one that there is a reduction of GHG emissions compared with those associated with traditional practices of storage and distribution of raw manure. Unlike other types of renewable energies, the process is natural, not requiring energy for the generation process.

An additional benefit is the digested slurry which can be dried and sold as high quality manure. A variety of byproducts can be created from the digestate solid and liquid. They are great fertilisers, with added benefits from the active bacteria in the digestate which can make plants healthier and as a result not only produce more, but also survive better when under stress such as heat and drought.

This all happens during the methanogenesis stage of the process results in the production of methane (biogas) which can be used as an energy source. There is also carbon dioxide in the gas, and usually also some rather nasty hydrogen sulphide (the source of any bad egg smell). The raw gas also contains a number of other contaminants at low concentrations which are called trace substances.

The University of Science and Technology Houari Boumediene points out that the most important advantages of biogas is that one can retrofit easily the conventional combustion engines to be used for the new fuel.  It could be unsafe to burn this gas, but in terms of safety, the advantage is that it is generated mostly in anaerobic environment at low pressure, so oxygen concentration is such that an explosive atmosphere does not arise. Nevertheless, some technologies utilize air for reduction of H2S in biogas. Care is needed to avoid explosive atmospheres developing.

Featured image showing the advantages of biogas.

In some countries there is possible distribution via public power grid to enable efficient energy utilization. Otherwise, the most popular energy production is by the use of combustion engines to run electric generators and export the electricity to the local power distribution grid.

One advantage of biogas is that it can be produced anywhere that organic waste is stored (organic landfills, sewers, farms, etc. ). It can be produced in rural areas from readily available materials.

One main advantage of biogas is the waste reduction potential. Efficient biogas production removes solid carbon and converts that to the carbon in the resulting methane atoms (CH4). This reduces the mass of what is left afterwards, and this is called waste reduction.

Couple that with the advantage that it is created from residues and wastes. It has the truly "magic" ability to transform waste material into a valuable resource. That's not to be sneezed at in the conditions of today, in which many countries are facing enormous problems associated with overproduction of organic wastes. These come in ever larger quantities from industry, agriculture and households.

Finally, it can be produced from nearly all kinds of biological feedstocks. The range from sewage sludge to feathers, from manure to damaged flower market flowers, and of course waste food.

We hope that this has explained the advantages of biogas to you.

Please comment if you seek more information and we will do our best to answer you.

You can also watch this video on the YouTube Website here.

21 September 2018

4 Biofertilizer Facts All Agriculturists Need to Know

1. General purpose biofertilizers are available that help maintain the natural equilibrium between Organic Carbon N, P and K in the soil structure, eventually improving the health of the soil for better crops.

Liquid biofertilizer is increasingly available in the market as one of the alternatives to chemical fertilizer and pesticide. It also helps the rejuvenation of what might have become barren soil, making it possible to bring some land back into cultivation.

2. Many believe that biofertilizer is going to become a critically important tool in the average farmers toolbox.

Using it is enabling farmers and growers of any scale to use a high quality fertilizer (Biofertiliser Certification Scheme approved) with bacterial benefits. Biofertilizer combines the power of a balanced soil biology to build the soil food web, with the full array of trace elements and soil minerals needed for robustly healthy plant growth.

Image about the Biofertilizer Facts.

3. Biofertiliser is a ferment made from a biological base in water and enriched with foods to feed biology and minerals for biology to digest.

Using a product compliant with BSI PAS 110 and the ADQP will save tens of thousands of pounds on other fertilizers, and also provides important validation for farmers that biofertiliser is a safe, effective and environmentally friendly product.

4. Biofertilizer can replace chemical fertilizer in developing countries BY DEFAULT, because of price alone, for farm adjoining biogas plant facilities. It has been identified as an alternative to chemical fertilizer to increase soil fertility and crop production in sustainable farming. Plus, it can act as a catalytic agent, and can aid in the conversion, availability, transformation of the nutrients in the soil.

Summary of Biofertilizer Facts

The exploitation of beneficial microbes as a biofertilizer has become paramount importance in agriculture sector for their potential role in food safety and sustainable crop production.

The above biofertilizer video can also be seen on YouTube here.

27 August 2018

What is Biogas? Biogas Defined for Non-Scientists

Biogas is a renewable source of energy that belongs to the category of biofuels. It's predominantly a mixture of methane and carbon dioxide, and it's produced through anaerobic digestion, that is the bacterial fermentation of organic material.

Biogas is made in a biogas digester, and is a clean burning fuel (similar to LPG) once it has been cleaned up, with the big difference that you can make yourself. You can't make LPG, which is a fossil fuel and not renewable. Once the LPG has all been used up it will have gone for good!

Image features the wording "What is biogas?" Biogas Defined
Biogas Defined to Answer "What is Biogas?"

Biogas is often produced from animal and agricultural wastes, and should not be made from food crops. There is no need to make it from food crops anyway, because there are a huge number of sources of organic waste which would otherwise just be left to rot away or go to landfill.

It is used directly for lighting, for producing heat, and as a fuel source for fuel cells. Biogas can be cleaned and upgraded to natural gas standards, when it becomes bio-methane. It can be compressed, the same way as natural gas is compressed to CNG, and used to power motor vehicles.

It can be made in all sizes of digester designs from a home food scraps digester to a huge egg shaped digester which is used to process sewage sludge at the biggest of sewage works which serve half a large city or more.

When made in sufficent quantities in large digesters and upgraded to biomethane, it can then be injected into a gas grid. So, you may be using purified biogas in your gas stove or central heating alerady, especially if you live in the UK. Such gas will be a good supplement to the green power from wind and solar power, and the green district heating (called CHP) from the otherwise unused heat from the jackets of the generators in power stations.

The biogas will displace GHG emissions from kerosene and fuel wood that are currently used for cooking. It will also  displace GHG emissions from cattle manure that is currently dumped in pits near the household. It is considered to be a renewable resource because its production-and-use cycle is continuous, and when done very efficiently generates no net carbon dioxide.

There are many home and community digesters, but, the largest volume of produced globally biogas will, by 2020, originate from farm biogas and from large co-digestion biogas plants, integrated into commercial farming, and waste food food-processing anaerobic digestion plants. Unlike liquid biofuels, biogas does not compete with food, as it does not require dedicated crops and can use non-edible parts of plants.

Running parallel to this process, an artisan sector for the manufacturing and repairing of the equipment that utilizes biogas emerging. This provides skilled jobs for the local community. Jobs in which the workers can be proud of what they are doing. 

With the technological advancements in biogas which are moving the process forward into an era of far higher eficiency and reduced costs, installing an AD plant will be more justifiable as a profit making system. The only thing to suffer a potential disappearance as a result should be landfill, and everyone will be delighted with that!

The solid and liquid "digestate" which is the output from the anaerobic digester is a wonderful fertiliser, with improved characteristics to manure. Both fertiliser and fuel wood are increasingly expensive in the country, and biogas reduces the demand for wood fuel. This is a potentially important future to help reduce the cost of firewood for those that need it. At the same time the depletion of forests for firewood should slow down, or be reversed.

Biogas has a lot of potential. Nevertheless, it has also one natural element that can be easily forgotten; as the biogas production is a natural, not an artificial process. That is that it needs to be controlled by trained experts to ensure optimum reiability and gas yield.

Accordingly, along with natural gas, biogas may be considered as a bridge fuel for the twentieth century, enabling the transition to a low-carbon energy economy, currently playing a key role in the emerging market for renewable energy. In fact, biogas may well represent one of our most important weapons in the fight against climate change.

Home biogas is highly efficient as it is used where it is made! Even in commercial applications the delivery of biogas can be often be done without causing any transport emissions at all when it is supplied to the landfill fleet operator's vehicles such as the waste collection trucks which operate from the same site as the biogas plant, or landfill. In addition to lower predicted upfront cost than nuclear power, home biogas does not require a grid-tie or any type of energy storage, as energy is stored in gas form and used on-demand when needed.

Biogas does require treatment or 'scrubbing' to refine it for before it can be used as a fuel for normal engines. Carbon dioxide (up to 20%), and hydrogen sulphide in small quantities are removed this way simply by passing the raw biogas through water. The carbon dioxide, and sometimes this sulphur as well, once removed from biogas can itself be sold profitably for a myriad of uses. 

16 January 2018

Digestate Fertiliser Regulations Needed for Anaerobic Digestion Throughout Europe

Consistent digestate fertiliser regulations are urgently needed for Anaerobic Digestion to thrive throughout Europe. Without them selling sustainable, low carbon emissions digestate derived fertiliser will continue to be held back.

Under the current legislative regulation on the use of digestate in the EU, the digestate is considered as waste in most of the EU Member States. 

The result of that is that to sell digestate fertiliser outside the farm it is produced is a painful exercise, and very few producers put their digestate on the market as fertiliser.

Watch our video about this below, and then scroll down and please give us your comments:

Digestate is a really good fertiliser, and it holds interesting benefits over chemical fertilisers, but there are some real concerns to be resolved before the regulatory bodies can allow it to be placed on the market. 

This is why we make a plea for the EU bodies responsible to act and as rapidly as possible issue new regulations for all fertilisers to harmonise the situation in the EU. 

The EU regulators need to get together a project and regulate digestate fertiliser EU wide, through the Fertiliser Regulations.

Fertiliser Regulations are an important piece of legislation which should be revised to involve, among others, the sale of digestate as fertilising material, providing conditions are met to ensure the quality of the fertiliser products and their safety against spreading any infectious diseases they might spread if they are not properly pasteurised.

We are in agreement with the European Biogas Association on this, as described in the video below:


For this the EU Law needs to change the status of anaerobic digestion digestate from being classed as a "waste", to being classed as a product. That is from a so called "waste" to it being seen as a valuable raw material to be used for fertilising and soil improvement generally.

This is the first step. The second step is that digestate contains manure.

Manure is generally considered to be an Animal By-product (ABP), and the new Fertiliser Regulations need to change the status of Animal By-product to allow it to become a fertiliser.

The spokesperson in the video above said:

"We are working on the integration of all these existing pieces of legislation into one, which will be the fertiliser regulation. And the purpose of my talk today was to present this aspect of integration of several pieces of legislation into one, which will be helpful for the digestate producer and this will actually be a way to also make money out of the digestate by placing this useful fertilising method on the market."

"Which countries in Europe are the best from this point of view?"

"Well, the most active countries that we have are typically Germany but also France, as they think about changing the legal status of this digestate and that is why we get inspiration to harmonise this at a European level."

"This is really important because we want to create a level playing field for this digestive derived fertiliser compared to the mineral fertiliser."

"We buy and manufacture the mineral fertilisers, they are very important [to reduce] for their high carbon footprint, which is detrimental to the environment."

It is better to use the resources we already have in our biogas plants. After all, we are living on the biogas resource, producing energy first, but now we must also start using the digestate as the great fertiliser it can be.

This is also a great way to integrate farming practices into a circular economy. It is a way to increase recycling, and to transform the farmer as a real actor of the new circular economy.

Video and quoted text are as found on Youtube here.

22 October 2017

Anaerobic Digestion News: IADAB News Weekly - Edition 5: Biogas Powered Fuel...

Anaerobic Digestion News: IADAB News Weekly - Edition 5: Biogas Powered Fuel...:

The IADAB Anaerobic Digestion and Biogas News Weekly - Issue 5: 20 October 2017 This is Issue 5 of the IADAB News Weekly where we provide a summary of this weeks top news stories.

14 September 2017

Anaerobic Digestion News: Anaerobic Digestion of Dog Poop Fuelled a Pacific ...

Anaerobic Digestion News: Anaerobic Digestion of Dog Poop Fuelled a Pacific ...: The story of anaerobic digestion of dog poop which at first simply lights a park lamp, but can do much more in future, is a fascinating one...

If anyone reading this knows about the current fate of any of the park lamp biogas plants we would love to know what has happened since 2013? Are the original lamps still biogas lit?

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