Recycling Africa’s agro-industrial wastewaters: Innovative system is piloted for Kampala City Abattoir

A holding tank for recycling wastewater at the city abattoir in Kampala.

A holding tank for recycling wastewater at Kampala City Abattoir (photo credit: ILRI/Albert Mwangi).

Note: This post was developed by Bio-Innovate communications officer Albert Mwangi.

A clamor to improve Africa’s agricultural value chains by greater industrialization of many of Africa’s agricultural processes was heard often at the just-completed sixth Africa Agricultural Science Week (AASW6), held in Accra 15–20 Jul 2013 and organized by the Forum for Agricultural Research in Africa. Most African nations are already pushing to add value to their primary agricultural commodities by supporting the establishment of relevant production and manufacturing processes and industries. Their aim is to transform their role as producers of primary agricultural commodities, such as whole raw coffee beans, into exporters of near-finished agricultural products, such as finely graded and ground coffees, thus earning more from their agriculture sectors.

Several of Africa’s livestock-based economies are working to add value to their production of leather. Rather than drying the skins and hides of slaughtered domestic animals and selling these as is, the skins and hides in addition are softened, graded and cut for various products, and in some cases used to produce finished leather products for export. While economically desirable, the production and manufacturing processes employed in this kind of industrialization can pose significant environmental risks, in this case, for example, by contaminating and/or polluting riverine eco-systems, water bodies and groundwater sources with heavy metals and other toxic substances.

Last week, Nigerian blogger Bunmi Ajilore, an advocate of sustainable agriculture and environmental justice, gave a succinct description of the public health hazards as well as benefits of using wastewater in agricultural activities (The use of wastewater in agriculture: The nagging dilemma, posted on his EcoAgriculturist Blog and reposted on the FARA–AASW Blog).

A research-for-development program based in eastern Africa known as ‘Bio-resources Innovations Network for Eastern Africa Development’, or Bio-Innovate for short, is working to deliver innovations in the recycling of agro-wastewater from industrial processes. A pilot project being implemented in Ethiopia, Uganda and Tanzania, for example, is working to develop safe and sustainable agro-processes for waste treatment and these will soon be scaled out to other agro-industries in the eastern Africa region.

The city abattoir in Kampala, Uganda, a partner in this Bio-Innovate project, illustrates ways in which the project is helping to make recycling processes both safe and sustainable. These processes are being integrated in ways to, simultaneously, reduce pollution, generate energy and recover nutrients from agro-process wastewaters.

Wastewater recycling at the city abattoir in Kampala
A 2005 publication by Joseph Kyambadde (Integrated Process for Sustainable Agro-process Waste Treatment and Climate Change Mitigation in Eastern Africa) showed that a good number of industrial activities in this region release inadequately treated wastewaters into the environment. The study further indicated that effluent from Kampala City Abattoir significantly harms the ecology and water quality of Lake Victoria’s Inner Murchison Bay, source of Kampala’s drinking water.

The abattoir has a slaughter capacity of 500–600 cattle and 200–300 goats/sheep per day, with an estimated wastewater production of 200-400 m3 per day. This wastewater effluent generated by the abattoir is a major factor in nutrient enrichment and oxygen depletion in Lake Victoria.

Researchers at Uganda’s Makerere University, who are implementing this project, are working with staff of Kampala City Abattoir to create a ‘value-addition chain’ that involves bioconversion of slaughter wastes to produce biogas and production of nutrient-rich slurry for use in hydroponic systems, where plants are grown without soil, and as bio-fertilizer. In a pilot plant that has been set up, effluent from the abattoir is first treated in anaerobic and aerobic sequencing batch reactor (SBRs) digesters; the resulting digestate is separated into two components: a nutrient-rich sludge that will be converted to bio-fertilizer and treated effluent that has a reduced organic load. This effluent can then be used to cultivate vegetables, flowers and animal fodder in a hydroponic system constructed in an artificial wetland. The treated wastewaters have great potential also for industrial use in cleaning the slaughtering areas, animal storage facilities and public toilets. This system combines bio-digestion of waste to reduce the organic load and generate biogas and electricity; utilization of nutrient-rich effluent for hydroponics; and artificial wetlands to further clean the effluent before release into the environment. This integrated system not only is an innovative way to manage and recycle wastewater sustainably but also provides people with sufficient incentives for such recycling.

The biogas and electricity generated by this integrated wastewater management / recycling system can be used as an alternative energy source, and so help reduce deforestation, which generates the greenhouse gases causing climate change. As noted, other products generated by the system can be used as affordable bio-fertilizer. And of course a further benefit is better protection of freshwater resources.

By treating agro-process waste in such an integrated way, this project is helping Kampala City Abbattoir to protect Uganda’s environment and livestock livelihoods alike. It is the aim of Bio-Innovate and its Ugandan colleagues to replicate this pilot system in suitable places elsewhere on the continent to help Africa’s expanding agro-industries make safer and better use of their wastewater.

About Bio-Innovate
Bio-Innovate makes use of advanced biosciences both to increase efficiencies in agro-processing and to make more sustainable use of local bio-resources. The program is based at the Nairobi, Kenya, headquarters of the International Livestock Research Institute (ILRI website). For further information, contact Albert Mwangi, Bio-Innovate communications officer, at a.mwangi [at] cigar.org

About AASW6
FARA website’s 6th Africa Agriculture Science Week (AASW6), in Accra, Ghana, included marketplace exhibitions (15–20 Jul 2013), side events on sub-themes (15–16), a ministerial roundtable alongside a Ghana Day (17 Jul), plenary sessions (18–19) and a FARA Business Meeting (20 Jul). The discussions were followed on Twitter (search for #AASW6) and blogged about on the FARA-AASW6 blog.

New paper quantifies the global role of livestock as a nutrient source for the first time

Mario Herrero, systems analyst at the Africa-based International Livestock Research Institute (ILRI), is co-author of a paper to be published today in the prestigious US Proceedings of the National Academy of Sciences (PNAS). The paper quantifies the role of livestock as a nutrient source globally for the first time. The paper, ‘A high-resolution assessment on global nitrogen flows in cropland’, reports results of an investigation of the sources of nitrogen for crop production globally. ‘We quantified the role of manure in different continents and in different agricultural production systems,’ says Herrero. ‘We found large differences in manure levels. In large parts of Africa and South Asia, which have the greatest numbers of poor people in the world, most of whom make a living by farming, manure can represent 35-40% of the nitrogen needed for growing crops, making it a major source of needed nutrients in these regions,’ Herrero. Elsewhere, he explained, where farmers have ready access to chemical fertilizers, manure plays a less important role in crop production. The paper shows that livestock manure is as important a nutrient contributor as (and in some regions, is even more important than) the stalks, leaves and other wastes of crops after harvesting, which are often fed back into soils to help enrich them for the next cropping season. But those crop residues are becoming increasingly scarce due to their competitive uses. And one of the biggest competitive uses is as animal feed. Many farmers are loath to put their crop residues back into their soils because they need them to feed their animals. In South Asia and sub-Saharan Africa, crop wastes represent between 40 and 60% of all the feed for the cattle, sheep, goats and other ruminant animals raised. ‘Crop residues are a hugely important resource,’ says Herrero. ‘And needing to keep these resources to feed their animals stops many farmers from adopting conservation agriculture, which requires putting the residues back into the ground.’ Of course, the animals consuming crop residues deposit their manure on the ground. This analysis by Hererro and colleagues suggests that, globally speaking, livestock manure and crop residues make similar levels of contributions to nutrient levels. ‘In developing countries,’ he says, ‘the best solution is often for a farmer to feed her crop residues to her ruminant animals and then fertilize her soils with the manure they produce.’ That’s because these farm animals provide poor farmers with many other essentials as well, including highly nourishing animal-source foods for the household, much-needed year-round cash incomes, and draught power, transport and other inputs for successful cropping. ‘The bad news,’ says Herrero, ‘is that the amount of manure we have in Africa and South Asia is not nearly enough to increase levels of crop production. And to feed the world’s growing human populations, we’re going to have to increase the amount of nutrients we’re providing the soils in these regions.’

Feeding livestock, sustaining soils: Crop-livestock tradeoffs focus of SLP discussions

This week, ILRI Addis Ababa hosted a meeting of the Livestock Programme Group that steers the CGIAR’s Systemwide Livestock Programme (SLP). The Programme builds synergies between crop research and livestock research across the CGIAR.

A major discussion point at the meeting is the “pressure on biomass use in systems.”

Bruno Gerard, SLP Coordinator, explains that the group will look especially at tradeoffs in the use of crop residues – between feeding livestock or sustaining soils.

View his video:

[blip.tv ?posts_id=2967023&dest=-1]

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ILRI weighs in on agricultural research e-consultations

What’s Needed? What’s Missing? What’s New? in Asia

ILRI Livestock analysts in India, New DelhiWhat should be the future agriculture and natural resource research agenda?  That is the big question being asked in a series of electronic consultations being held in different regions of the world. The answer will determine the way that millions of dollars are spent in the coming years by the Consultative Group on International Agricultural Research (CGIAR).  The regional e-consultations will feed into a Global Conference on Agricultural Research for Development (GCARD), to be held in Montpellier, France, in March 2010.
This Global Conference is being designed as a multi-year process creating new ways of working together that significantly enhance the development value of agricultural research. The organizers are designing GCARD to be open and inclusive and to help reshape agricultural research and innovation for development through an agreed action plan and new framework. In doing so, they are also ambitious to increase the resources for, and benefits of, such research. Iain Wright, Regional Representative for Asia at the International Livestock Research Institute (ILRI), made the following responses to nine questions posed in September 2009 in this GCARD 2010 e-consultation for the Asia-Pacific region.

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Nourishing the soil, feeding the continent

Participants at the Africa Fertilizer Summit held in Abuja, Nigeria, 9-13 June 2006 heard how livestock manure is protecting soils across West Africa's dryland farming systems.
 
Innovative policies and practices are turning around Africa's soil fertility decline. Reversing the decline is vital if farmers are to have a chance to improve their livelihoods through more intensive agricultural production. Livestock are key to protecting Africa’s soils. Even modest increases in the use of livestock manure and fertilizers could trigger an African Green Revolution.