From city ‘Takataka’ to cheap, quality fertiliser

In 2004, Intermediate Technology Development Group (ITDG) estimated that Nairobi produces about 2,400 tonnes of municipal solid waste (MSW) daily. This generation stands at 4,398 tonnes per day in 2015 and is projected to hit 7,427 tonnes per day in 2030 based on population and economic growth trends.

The United Nations Environmental Programme (UNEP) and the National Environment Management Authority (NEMA) determined that domestic waste contributes 68 per cent of the total waste generated in Nairobi. Of all this trash — both food and non-food — only 33 per cent is collected following disposal in a manner comparatively friendly to the environment.

It is for this reason that a local enterprise, Takataka Solutions, developed an innovative waste management model for recycling and composting the solid waste. To make their collection and recycling easier, the company has opted to separate the solid waste at source.

While the separated fractions are stored in chambers and sold out to other partners, the organic waste is handled at Takataka’s composting facility in Kangemi as there is currently no recycling of organic waste.

Farm trials

“We process the organic waste into natural fertiliser which we sell to small, medium scale and horticultural farmers,” says Susan Letuya, the partnership manager at Takataka Solutions.

Letuya says organic fertiliser not only results in better farm yields and improves the structure of the soil, it is also cheaper compared to inorganic fertiliser by up to 10 times.

To enhance the farmer’s experience, the natural fertiliser is further categorised into two lines— taka compost for the urban market and Soil Plus for the rural market.

“Other than training farmers on the use and benefits of organic fertilisers, to those not receptive to the idea of organic fertilisers, we conduct trials on their farms so they can see for themselves the comparable results of their yields while using both organic and inorganic fertilisers,” says Letuya, who has worked at Takataka Solutions since its establishment in 2011.

To process the natural fertiliser, all organic waste is collected, heaped and manually rotated every fortnight for aeration. This goes on for 15 weeks until the waste has completely decomposed into organic fertiliser.

Bulking agents such as wood chips are placed inside the waste to ensure that as it decomposes, it does not cling to each other, making it even easier during rotation.

The compost only smells bad for the first few days, beyond which there are no odours or emissions, allowing habitable living conditions for the residential houses located just 10 metres from the plant.

Whenever it rains, the organic waste is covered to prevent generation of leachate — liquid waste released by the decomposing matter that can contaminate surface and groundwater.

When the fertiliser is ready for use, it is packaged and sold. Through this process, Takataka Solutions processes five to six tonnes of organic waste a day. Since receiving a $50,000 (Sh5.1 million) award at the Dell Social Innovation Challenge, the company has sought to expand its organic composting model by constructing a larger composting facility to produce natural fertiliser for a growing market. To expand its capacity, it used the expertise  of Gore Cover, a trendsetting intelligent technology with integrated protection against weather, emissions and odour.

Power generation

Through this technology, Takataka Solutions is able to increase the efficiency of the plant by processing 25 tonnes a day, a significant increase from the six tonnes it was previously processing. The result is higher output on a smaller footprint of composting area — with little energy consumption and human involvement.

Its unique design means that it is capable of processing a variety of materials, from  green waste, food waste, paper sludge, source separated organics, biosolids or Municipal Solid waste (MSW). It can process volumes from as little as 2,000 tonnes to as much as 200,000 tonnes per year.

Unlike the manual process which takes 15 weeks, and needs turning every fortnight, this technology processes the waste into natural fertiliser in eight weeks. The only other check is made at week four to find out if its content has thoroughly decomposed.

Other than being efficient, it is cost effective as one does not need expensive buildings and additional bio-filtering installations.

It meets the strictest of regulatory requirements by operating within threshold limits at all times, having been approved and proven to work in more than 150 composting plants in more than 20 countries, including Sweden that recycles 99 per cent of its waste and even imports waste from other countries to generate power