Biosolid is the byproduct of the wastewater treatment process, which instead of throwing it away, can be used for various purposes.

Biosolid is produced in tons every year. And every time, we throw away so much biosolid without batting an eye. From small activities like gardening to big construction projects, biosolid has been used in all activities. 

If we use biosolid to its full potential, perhaps we would not need to burn fossil fuels. Below are the ten ways for mitigation and management of biosolid. 

1. Fertilizers

Biosolid is enriched in nutrients such as phosphorus, zinc, nitrogen, and so on, which is vital for healthy plant growth. 

The phosphorus and other nutrients are responsible for harvesting the sun rays and converting them into growth and reproduction.

The nutrients are already in the plants. Some plants may not have enough nutrients to function correctly. 

Thus, an additional help of biosolid may provide the plants with proper nutrients to carry out reproduction. The plants and biosolid also improve soil qualities by enriching organic matter. 

Using biosolid can prevent soil erosion. The biosolid enriched soil develops thick vegetation and binds water that limits sediments runoff during rain. 

Biosolid also has a play in preserving the ecosystem. It nourishes the soil organisms, making the soil fertile in the long run.

2. Construction materials 

biosolid bricks
Biosolid bricks made in RMIT university| Photo from new atlas

One of them is the production of construction materials. RMIT University in Melbourne, Australia, has stated that fire clay brick with biosolid can be the optimal choice for brick-making and wastewater treatment industries. 

The biosolid brick only requires half of the production energy than conventional bricks. The bricks are produced at a lower price; the biosolid bricks have low thermal conductivity. 

The bricks transfer less heat in comparison to the conventional bricks used nowadays. Thus, buildings made with biosolid provide a naturally stimulating environment. It could be a sustainable use of excessive biosolid. 

The biosolid bricks have passed the physical strength test. Before bringing it to the market without any hesitation, the bricks are going through other types of chemical tests. 

3. Surface disposal

Another use of biosolid is surface disposal. Surface disposal is the stockpiling of sludge, faces, and biosolid that doesn’t have an imminent use. 

Surface disposal is carried out when there is no need for the materials and anticipated future use. The process is also carried out to dry the materials before using them.  

The process is operated at low costs, does not require high-level knowledge, and helps prevent the unmitigated disposal of biosolids.

Surface disposal has its drawbacks as well. It occupies a large piece of land. The biosolid nutrients leach into the groundwater if kept at disposal for long. 

The disposal pit will produce a pungent smell. Removing odor may require various treatments. The surface disposal needs to be built far away from the pedestrian areas to prevent health problems.

4. Oil

That’s true; Oil from biosolid can replicate the oil from fossil fuels. The Australian renewable energy agency (ARENA) funded 4 million US dollars to the southern oil refinery for its plan to turn biosolid waste from sewage into crude oil. 

It has been two years, and the results show that biosolid can be converted into bio-crude. 

The organization successfully creates biodiesel, indistinguishable from fossil fuels, from biosolid by using the process of thermochemical conversion. 

Due to this support from ARENA, the initial plans are already implemented. It is going to boost Australia’s independence. 

The biosolid will be produced in tons each year, so there is no scarcity of raw materials. The fuel may be locally available and cheap once the crude is produced in large amounts.

Although there are no technical difficulties in making the oil, the investment for the process could cost an arm and a leg.

5. Rehabilitating mining sites

Land application of biosolids
Land application of biosolid| Infographics by Wijesekara et al., 2016

The mining process degrades the site soil and makes it infertile. It exacerbates soil conditions, including microbial activity, flora, and fauna.

A shortfall in topsoil, heavy metal-rich tailings, residual soil is the consequences of degraded mine soil. In addition, the mining process degrades the soil’s physical properties and renders it less organic. 

Here, biosolid can come to use. As of now, many mining sites have been recovered from the aftermath of mining. 

With biosolids, the biological, chemical, and physical properties of land have been restored. It promoted the re-establishment of lost ecological integrity. 

Furthermore, the nutrient cycle, water purification, and recreation values of lands are better than ever with the help of biosolids. The process helped for the emergence of a novel ecosystem. 

6. Alkaline stabilizer

Another function of biosolid can be an alkaline stabilizer. Many agricultural lands are barren for various reasons.

One of them is because of the presence of alkaline soil. The alkaline soil causes multiple problems to already existing plants in the land. So to solve the alkaline soil problems, put some alkaline stabilizer.

Biosolid is an organic substance that can work as an alkaline stabilizer. When an optimal amount of biosolid is added to the soil, the microbes decompose the materials that release carbon dioxide gas.

The carbon dioxide gas reacts and produces carbonic acid. However, the biosolid cannot be dumped into the land without proper prescription. 

Multiple tests are required to use the right amount of biosolid in the right way. It will balance out the ph value of soil and make the land cultivable. 

7. Vitrification

The wastewater treatment system produces a large amount of disposable biosolid. Such sludges produced from the process will be a liability to the environment and a burden to the economy. 

Vitrification provides a way to manage the biosolid efficiently. Vitrification is a sustainable approach to handle the tons of biosolid that are not brought into use.

Vitrification is the process of forming a glass. It is done by melting the crystalline silicate compound into the amorphous with the non-crystalline atomic structure associated with glass.

The glass is called bioactive glass produced by the process and can be used in many areas. The bioactive glass has a wide range of dental and medical applications

The glasses are currently used as bone grafts, scaffolds, and coating material for dental implants. 

Many companies have already started introducing vitrification technology to recycle high volumes of waste, such as biosolid. 

8. Incineration

wastewater treatment using biosolid
Wastewater treatment using biosolid| Info Charts by MDEQ

Incineration is a wastewater treatment process. In the process, the substances in the waste material are combusted in the presence of air. 

The process takes place in two steps. Firstly, the biosolid is dried, so their temperature is raised to the point that water in the solids evaporates.

Secondly, the biosolid is combusted to small fractions. The ash produced by burning up the waste materials or biosolid can be used for many purposes. 

The ashes work as a subbase material for road construction. It can also be used as an ingredient in footing at athletic and equestrian facilities, such as race tracks and arenas.

It is also a little eco-friendly method to manage the biosolid as it produces lower NO₂ and CO2 gases that contribute to global warming.

The process requires less power and lower maintenance costs. The plants are easy to control. Thus, incineration could be an excellent option to manage a biosolid.

9. Forestry 

Deforestation is one of the most significant environmental issues of today’s world. Many species are cut every day to the extent of bringing them to the brink of extinction. 

As we know, the lives of humans and biodiversity are interconnected. If they survive, then we can. There is a way to balance out the deforestation done in the past, which is planting new trees. 

The plants take time to grow. Hence, biosolid can be used to promote the rapid growth of plants. The biosolid contains minerals that promote the development of plants rapidly.

It provides a solid immunity to plants to fight any diseases. The calcium in the biosolid helps trees support their cell walls, while magnesium in the plant helps them for photosynthesis. 

Without the magnesium, the trees cannot capture the sun energy required for photosynthesis. The biosolid can be used in forestry to provide all the plant’s nutrients.

10. Metal extraction

experimental design of metal extraction using sewage biosolid
Experimental design of metal extraction using sewage biosolids| Design by Ozdemir et al., 2020

The studies show that six metals, zinc, nickel, cr, PB, Cu, and cd, can be removed efficiently from anaerobically digested biosolid using chemical extraction.

It is done to prevent the land from any damages caused by the metals in biosolid. Metals are extracted from the biosolid. 

Two organic acids, two inorganic acids, and one potent chelator are required for metal extraction at different concentrations and reaction time conditions.

The biosolid used as the fertilizer will be devoid of elements, so the land and soil will not suffer from adverse effects

Hitting two birds with one stone is the perfect aphorism for such a condition. The elements extracted can be used for various purposes. 

Wrapping Up

From the points mentioned above, it is concluded that biosolid can be the material for so many purposes.

It can provide us with fuel, construction materials, and ceramics. The biosolid can improve crop production, alleviate deforestation, rehabilitate mining sites, and so on.

Countries like Ethiopia, Malaysia, Japan, and many others with high deforestation can use biosolids to bring back greenery. Check out our article on ten countries with the highest deforestation rates.

Glasses are manufactured from biosolid serving a massive purpose in the medical and dental fields. 

The biosolid can be used for purposes other than the mentioned points. Thus, not even a single drop of biosolid goes to waste. 

(Last Updated on February 2, 2022 by Sadrish Dabadi)

Saurav Khadka, with his A levels in computer science from Saipal Academy, owns a keen desire to know more about the environment. He wants to preach his knowledge to others by learning through his hobbies; reading, writing, traveling, and watching movies. He believes sharing his insight regarding a sustainable environment will undoubtedly generate positive perceptions in the people.