Circular economy

Making compost out of sludge and sugar refinery waste

Stéphanie Jacob L'Economiste | Updated on January 15, 2018 Published on November 03, 2016

The Biochemistry and Plant Biotechnology team at the Faculty of Sciences Semlalia of the University of Marrakech, in collaboration with Biodech Ltd. (a company specialised in waste recycling and compost), has developed a method of adding waste from sugar refineries to the sludge produced by wastewater treatment plants. Photo credit: BBP

More than 60% of household waste in Morocco is organic. Yet it goes untreated, ending up in landfills, where it contributes to the generation of greenhouse gases. The innovative company Biodech has come up with a solution that is both ecologically and economically viable, and which involves combining this waste with that of sugar refineries and other green waste to make compost.

Add the waste from sugar refineries to the sludge produced by WWTPs (wastewater treatment plants), and what do you get? According to research carried out by the Faculty of Sciences Semlalia at the Cadi Ayyad University of Marrakech, Morocco, in collaboration with the company Biodech Ltd – specialised in recycling waste – you get rich and useable compost.

Mixing WWTP waste with this sugar ‘scum’ – left over from the process of refining beetroot juice and sugar cane using lime, enables a reduction in both the bacterial content and the loss of gases from the resulting compost, while also improving its quality. This also means that such sugar refinery waste, which typically represents around 270,000 tonnes per year and normally ends up in landfill, has the potential to be instead transformed into something a little more useful.

The development of this technique also represents a business opportunity. The results of the experiments have so far been released at several national and international conferences, spreading the word that – from both physiochemical and bacteriological viewpoints – adding this sugar refinery waste and industrial sludge to compost is a step worth taking. Especially considering that this type of compost meets the French NFU 44095 standard, which outlines the specifications required for these types of WWTP related compost. Having been through a rigorous testing period, this method has produced some excellent results. A patent is soon to be filed.

“Legislation on water management (Law 10-95) and the National Liquid Sanitation Plan have succeeded in pushing municipalities, cities and industrial companies to develop water treatment and purification stations, WWTPs. These stations operate under different models to produce treated water, which is still not being recovered in Morocco, apart from by a few commendable initiatives,” explains Professor Khalid Fares, director of the project as part of the Biochemistry and Plant Biotechnology (BBP) team at Cadi Ayyad University. “In addition, the sludge is frequently discarded in or alongside public landfill sites. It’s the ‘missing’ link in Law 10-95.”

Initially, the compost produced by Biodech will only be used in recreational green spaces “as there is a strong resistance to change in Morocco, and the virtues of compost are widely unknown.”

Biodech was initially created through the Marrakesh University incubator by Fares and a fellow researcher from the Biochemistry and Plant Biotechnology (BBP) team, Nabila Saadaoui. The pair have already secured four Moroccan patents for their work on waste recovery, including three involving sugar refinery waste. The company is also working on other solutions including the composting of vegetable water; such as that contained in the cells of olives. This low-cost solution reduces the need for chemical fertilisers, with their detrimental effect on groundwater. Biodech was invited to present their findings at the COP21 climate conference last year.

600,000 tonnes by 2030

In its 2015 report on “The State of the Environment in Morocco”, the Ministry of Environment estimated that more than 60,000 tonnes of sludge is produced each year. According to the same report, by looking at the production of both urban and industrial sludge, this amount will reach more than 600,000 tonnes of dry matter per year by 2030, of which 500,000 tonnes would come from urban sources.

However, the majority of this waste material has a bacterial load and a chemical composition that can respond to a certain level of treatment and recycling – through composting. Thankfully, it has the advantage of being easy to process with only a very small investment required. The final product – compost – is rich in humic substances, which when reintroduced to the soil, improves its structure and organic content.

Follow us on Telegram, Facebook, Twitter, Instagram, YouTube and Linkedin. You can also download our Android App or IOS App.

Published on November 03, 2016
This article is closed for comments.
Please Email the Editor