Tag Archives: waste treatment

Almost half of the global waste is not collected properly — and much of it is burned

Nearly a billion tons of waste are disposed of improperly every year and this is threatening the health and wellbeing of billions worldwide, a new study reports. The study looked at what happens to consumer goods and other products at the end of their useful life and concludes that urgent action is needed to address open burning of solid waste and ill-managed dumpsites.

Image credit: Flickr / Fairphone

The “Global Review on Safer End of Engineered Life” report showed that of all the municipal solid waste generated on Earth, a quarter — half a billion tons — is not collected, and a further 27% is mismanaged following collection. This means that close to a billion tonnes of waste risk polluting the natural environment every year.

The biggest threat comes from the open burning of solid waste, the researchers found, which can damage the health of “tens of millions of people worldwide”. Waste is often burned close to homes, near industrial or commercial areas, and in large uncontrolled dumpsites, releasing emissions into the atmosphere and onto land.

The report also found that open burning releases persistent organic pollutants that are often carcinogenic, mutagenic, and cause immunological and developmental impairments or lead to reproductive abnormalities. It’s a “hazardous cocktail” that threatens the life of those who live and work nearby, the researchers note.

But it’s a difficult one to tackle, especially in developing countries, where it’s common for informal recyclers to set fire to electrical cables and electronic components as they have valuable metals bound with plastic. Also in households, burning food and biological waste can reduce its smell and discourages animals that might transmit disease.

“There is no doubt that the handling of humanity’s waste and its impact on health and safety should be much higher up the global agenda,” Willian Powrie, one of the authors and Southampton professor, said in a statement. “It beggars belief that we are still using crude and ancient methods of disposal to deal with our 21st-century waste problem.”

Engineering X, an international partnership founded by the Royal Academy of Engineering and Lloyd’s Register Foundation, commissioned the study to UK researchers and specialist organizations. They looked at the challenges to occupational and public safety from plastic waste, medical waste, electronic waste, construction waste and land disposal

Open burning was listed as one of the three challenges along with dumpsites and the challenges facing the world’s 11 million waste collectors. These are men, women and children that collect more than 90 million metric tons of waste for recycling each year while being exposed to many health risks such as open burning.

There’s a lack of data on where what and how much solid waste is currently burned, what is released during burning, and what impact burning has on people and the environment locally or on a wider scale, the researchers argued. Previous studies suggested that ending open burning would add a billion tons of solid waste to be treated.

Ruth Boumphrey, Director of Research at Lloyd’s Register Foundation, said in a statement: “Now is the time for collective action. It is unacceptable that in today’s world we do not have a proper understanding of how to safely and responsibly manage the waste from engineered items. We hope that this report will shine a spotlight on these long-neglected issues.”

The researchers made a set of recommendations for urgent action to mitigate harm. The amount of material disposed in dumpsites should be reduced, they argued, also calling for a transformation of existing dumpsites. Waste should be managed differently so populations don’t have to manage their own by open burning, while waste pickers should be part of the waste management plans.

They also listed suggestions for further research and innovation. They said more primary data on open burning should be collected, as well as assessing the benefits and motivations for open burning. Dumpsites should be better assessed, developing standards for their management, they argued, also calling for the empowerment of waste pickers.

Previous studies have warned over the growing amount of electronic waste generated every year. In 2019, 53.6 million tons of e-waste were generated by humans, almost two million metric tons more than the previous year. Only 17% of the waste was recycled, with the rest ending up in landfills, incinerated, or just unaccounted for.

New tech transforms human poop into clean biofuel

Credit: Pixabay.

Millions of people living in the developing world face a double challenge: sanitation and energy generation. Researchers at Ben-Gurion University of the Negev (BGU), Israel, have killed two birds with one stone by developing a solution that turns human excrement into hydrochar, a readily-available fuel.

Dirty waste to clean fuel

According to the World Health Organization (WHO), 2.3 billion people still lack basic sanitation service. Of these, approximately 892 million people defecate in the open. Defecating outdoors bears a significant risk of contamination to the fresh water supply and is associated with the death of 700,000 children each year who contact diseases like diarrhea.

Exposure to germs not only puts children at risk of developing diseases but, over the long term, can also cause changes in the tissues of their intestines that prevent the absorption and use of nutrients in food — even when the child does not seem sick. A report authored by the World Bank found a link between open defecation and poor cognition among children. As such, open defecation threatens the human capital of developing countries.

“Human excreta are considered hazardous due to their potential to transmit disease,” said lead-author Prof. Amit Gross.”While it is rich in organic matter nutrients such as nitrogen, phosphorus and potassium, human waste also contains micro pollutants from pharmaceuticals, which can lead to environmental problems if not disposed or reused properly.”

BGU researchers sought to address this major world health issue by utilizing a process called hydrothermal carbonization (HTC). Inside a system that resembles a pressure cooker, the team heated raw solid human waste to three temperatures (180, 210, and 240° C) and reaction times (30, 60, and 120 minutes), which dehydrated the excrement, producing a solid known as hydrochar and a nutrient-rich liquid. Previously, the BGU research team had worked on poultry excrement.

Hydrochar produced from wood sample (Euc Amplifolie). Credit: Fang et al, Journal of Industrial and Engineering Chemistry.

Hydrochar produced from wood sample (Euc Amplifolie). Credit: Fang et al, Journal of Industrial and Engineering Chemistry.

Hydrochar is very similar to biochar, with some notable differences. While both are stable, carbon-rich solid by-products, the two chars have significantly different physiochemical properties that affect their potential applications. These include but is not limited to carbon sequestration, soil amelioration, bioenergy production, and wastewater pollution remediation. While biochar is the result of slow-pyrolysis (essentially burning without a flame), hydrochar is produced with hot compressed water instead of drying. Another advantage is that HTC yields higher amounts of char and uses lower amounts of energy than pyrolysis.

Hydrochar can be used as coal, for household heating and cooking, replacing wood. Used this way, hydrochar lessens the carbon footprint of communities by preventing deforestation, soil erosion, and greenhouse gas pollution. Due to the high temperatures involved in HTC process, the resulting hydrochar is sterilized and safe to handle. The aqueous byproduct can be employed as fertilizer, the authors reported in the Journal of Cleaner Production.

It remains to be seen how this technology can be brought to scale to those who need it the most. In the meantime, with World Toilet Day just around the corner (November 19), it’s good to take a moment to appreciate the invention that saved the most lives in history: the flushing toilet.