Nawassco ventures in to producing fertilizer out of human waste

Kevin Nakitare demonstrates how to use organic fertiliser on at a field in Nakuru. (PHOTO: Caroline Chebet)

NAKURU, KENYA: Nakuru Water and Sanitation Service Company (Nawassco) is producing organic fertiliser from human waste.

Through a collaboration with researchers from Egerton University, the firm has produced the newest fertiliser varieties in the market, Struvide and Biochar.

Scientists say the venture will address soil degradation as well as sanitation challenges. Struvide is made out of human urine while Biochar is made out of carbonised human faeces.

“Various studies and tests indicate that the two fertiliser varieties are safe for use. While Struvide is rich in phosphorous compared to other fertilisers in the market, Biochar is rich in nitrates,” said Kevin Nakitare, a soil research scientist from Egerton University.

According to Mr Nakitare, early tests were conducted on different soils in several parts of Nakuru and good results were posted.

“We have conducted several trials in different regions with different soil varieties and the results are positive. The two (fertiliser) varieties are rich in nutrients. Apart from addressing soil degradation, sanitation challenges will also be tackled,” Nakitare said.

He revealed that producing Struvide was a challenge, especially collecting the raw material as the majority of toilet users often flush after use.

“It is one of the greatest challenges because not many people are aware that urine can be used economically,” Nakitare said, adding that the urine was mixed with magnesium oxide to crystalise it.

He also said production was expensive because of having to sourcema gnesium oxide.

“There should be specialised facilities for the collection of urine. A lot of awareness is also needed,” he said.

Nakitare however revealed that initial tests conducted on maize yielded excellent results.

Producing Biochar is not as difficult because sludge is easily obtained from the domestic sewage treatment plant.

“Nawassco carries out part of the activities in the treatment of sewerage and it is easier to obtain sludge that is then carbonised and made into granules,” said Mwende Osur from Nawassco.

Plans to expand production are underway.

“The biggest challenge we have is lack of funding," said Ms Osur. "But once resolved, expansion will be achieved."

Once the sludge is collected from exhausters, excess water is allowed to evaporate until the residue is dry, after which it is subjected to very high temperatures through carbonisation and finally granulised.

All harmful bacteria is killed during carbonisation.

According to Wilson Ngeno, an agricultural officer, the new fertiliser will help to address leaching problems.

“Farmers have been battling soil degradation as a result of constant fertiliser use but the organic varieties should address the problem,” he said.