Sanitising wastewater to save lives, environment


Treatment levels at Ecocycle. The bottle on the right shows raw sewage: the one in the centre shows water in SRB (Sequential Batch Reactor) after treatment, while the one on the left represents treated clean water. (Courtesy)

Every day, on average, a human being produces 150 litres of waste water through bathing, flushing the toilet, washing a plate on which they ate, among other needs, says Lucy Wanjiku Mutinda, the Engineering Director of Ecocycle Ltd, Kenya.

She was last week in Kigali for the 2nd Africa Engineering Conference and the 4th United Nations Educational, Scientific and Cultural Organisation (UNESCO) Africa Engineering Week 2017, held under the theme “Effective Waste Management in Africa”.

Wanjiku is a Kenyan who turns liquid waste into usable water to ensure zero wastage and sustainable solutions for the environment.

She treats waste water including that from the toilets, bathrooms, and kitchen.

According to World Water Day factsheet, over 80 per cent of the wastewater generated by communities around the world flows back into the ecosystem without being treated or reused.

And, 1.8 billion people use a source of drinking water contaminated with human waste, including faeces putting them at risk of contracting cholera, dysentery, typhoid and polio. 

In addition, unsafe water, poor sanitation and hygiene cause around 842,000 deaths each year.

The Ecocycle wastewater recycling plants help generate clean water, ideal for use in flushing toilets, irrigation, carwash, firefighting, and dust suppression.

Talking about the contribution of the technology to waste treatment and people’s health, Wanjiku said that they have installed systems that recycle almost a million litres of wastewater per day.

Wanjiku said that the technology, which was invented in Germany but customised for Africa, exceeds the ordinary water treatment standards level.

“So, that’s a big impact because the million litres of sewage that would be flowing every day is now retreated and reclaimed and reused to maintain green areas,” she told The New Times from Kigali. She founded Ecocycle in 2014.

Regarding the main driving force behind her project, she said; “I’m passionate about environment and wanted to use my engineering knowledge to help in protecting the environment. And living in Nairobi, I was always worried about the sewage flowing on the streets.”

Goal 3 of the global Sustainable Development Goals (SDGs) – (ensuring healthy lives and promoting well-being for all at all ages) – has a target to reduce substantially, by 2030, the number of deaths and illnesses from hazardous chemicals and air, water and soil pollution and contamination.

This was echoed by the engineers during their meeting in Kigali, where they committed to use their expertise to invoke technology that will facilitate the realisation of this goal on the African continent.

The technology includes small scale wastewater treatment systems for individual homes and large scale systems for communities like gated neighbourhoods, as well as shopping malls, institutions and apartments.

According to the UN Water’s 2017 World Water Development Report, Wastewater: The Untapped Resource”, improved waste water management is as much about reducing pollution at the source, as removing contaminants from wastewater flows, reusing reclaimed water and recovering useful by-products.

Together, it states, these four actions generate social, environmental and economic benefits for all society, contributing to overall well-being and health, water and food security, and sustainable development.

Wanjiku said that to reclaim 2,280 litres of water daily, the daily power consumption of the technology is 1.2Kwh, costing about $0.58 (some Rwf460).

“For a small blow, you are able to reclaim about 2,000 litres of wastewater per day, meaning [that] you save by the same volume your incoming freshwater intake,” Wanjiku said.

Overall, she said, for people or communities who have adopted such technology, it is helping them save $800 (about Rwf640,000) per annum, [compared to septic tank expenses.]

The cost of equipment for the treatment of waste for a family of between five and 12 people is about $3,800 (about Rw3 million). The client pays through three or four instalments.

The company gives the design and the customer has to pay for the civil works for the construction of the structure or tank to house the equipment, which ranges from $1,500 to $5,000 or so depending on the means and type

The wastewater treated by Wanjiku’s company can be reused to irrigate crops, but she recommends that farmers reuse it by dripping it onto the soil, not directly onto the leaves of the crops to avoid excess of nitrides, a chemical element with fertilizing traits.

Speaking during a news briefing ahead of the engineers’ conference, the Director General for Urban Development at the City of Kigali, Dr Alphonse Nkurunziza said there is a need for effective systems to treat wastewater, or liquid waste in general.

“Indeed, septic tank is a big issue. If we continue to set up septic tanks in the hilly areas of the [Kigali] City, it would be like sitting on a bomb that might explode one day. We should have systems that collect toilet wastes and treat them,” he said.