Small-scale Processing Plant of Sewage Sludge for gas / electricity / product production

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So the current wastewater per day is about 20000 litres, with a solid content of 4000mg/litre

About 60kg of solid a day, assume 40% of it is removed in treating, leaving about 48 kg a day of solid

Volatile solids is about 70%

Any ideas of what, if any processing plants on a very small scale or even just units, that can be used to make something that is economically viable, whether it be incineration, composting, anaerobic digestion, pyrolysis etc

 

Current cost of disposal is £8000 a month , so worth taking it into account for payback time

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6 Answers

  2. That is a well known fact.  It may sound like science fiction, but wastewater treatment plants across the United States may one day turn ordinary sewage into biocrude oil, thanks to new research. The technology, hydrothermal liquefaction, mimics the geological conditions Earth uses to create crude oil, using high pressure and temperature to achieve in minutes something that takes Mother Nature millions of years.

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  3. composting your bio solids would be the most economical way out. You can visit teamonebiotech.com for more details

  5. How about using Algae (www.i-phyc.com) to clean your waste waster.  It takes up P and NH4 and other contaminants.  We use the excess algae to reseed other plants or it can be used in fertilizer or Ink.  If you would like to know more please do get in touch.  Justine.buxton@i-phyc.com

  6. Answer from ChatGPT: 

    With the given information, there are several small-scale processing options that can be considered to convert the wastewater solids into something that is economically viable:

    1. Composting: The solid waste can be composted using aerobic methods, which can be done in small-scale units. The end product of composting is a nutrient-rich soil amendment that can be used for gardening or agriculture.

    2. Vermicomposting: This is similar to composting, but it involves using earthworms to break down the solid waste. Vermicomposting can be done in small-scale units and the end product is a high-quality organic fertilizer.

    3. Anaerobic digestion: This is a process that breaks down organic matter in the absence of oxygen and produces biogas as a byproduct. The biogas can be used as a renewable energy source, while the digested solids can be used as fertilizer or soil conditioner.

    4. Pyrolysis: This is a thermal process that converts organic matter into a biochar, which can be used as a soil amendment or activated carbon. Pyrolysis can be done in small-scale units, but it requires a higher investment cost compared to composting or anaerobic digestion.

    5. Incineration: This is a thermal process that burns the solid waste and produces ash as a byproduct. Incineration is not recommended for small-scale processing due to its high investment and operational costs, as well as potential environmental and health hazards associated with air pollution.

    In general, composting and vermicomposting are the most viable and cost-effective options for small-scale processing of wastewater solids. Anaerobic digestion and pyrolysis may require a higher investment cost, but they can also provide additional benefits such as renewable energy production and biochar production.

     

    Based on the information provided, here are some potential small-scale processing options and their estimated payback time, taking into account the current cost of disposal of $10,000 per month:

    1. Anaerobic digestion: This process can convert organic waste into biogas, which can be used for energy generation. The payback time for anaerobic digestion systems varies widely depending on the size of the system, the amount of organic waste being processed, and other factors. However, a small-scale system could potentially pay for itself within 2-5 years.

    2. Composting: Composting is a natural process that breaks down organic matter into a nutrient-rich soil amendment. Small-scale composting systems can be relatively simple and inexpensive to set up and maintain. Depending on the specific system used, the payback time for a small-scale composting system could be as little as 6-12 months.

    3. Pyrolysis: Pyrolysis is a process that involves heating organic material in the absence of oxygen to produce a biochar and a liquid or gas byproduct. Small-scale pyrolysis systems can be expensive to set up, but they have the potential to generate income from the sale of biochar or other byproducts. The payback time for a small-scale pyrolysis system could be several years or more.

    4. Incineration: Incineration is a high-temperature process that converts organic waste into ash and gas. Small-scale incineration systems can be costly to install and maintain, and they may not be practical for all types of waste. The payback time for a small-scale incineration system would depend on the specific system used, but it could be several years or more.

    It's worth noting that the payback time for these systems can vary widely depending on a number of factors, including the size and complexity of the system, the amount and type of waste being processed, and the local market for any byproducts that are generated. Additionally, there may be regulatory requirements or other factors that need to be taken into account when considering these processing options.