Dr.-Ing. Gerhard Schories: Water management to the very last drop

Africa’s water resources are limited, mainly depending on climate factors, essentially rainfalls and weather. Even the existing and available quantities of water are generally subject of low quality affecting people’s health and negatively impacting on agriculture.

Climate change has imposed additional pressure on water availability and acces­­sibility. In fact, water distribution in major parts of Africa tightly depends on the cli­­mate variable and consequently is char­acterized by complex patterns and op­­posite models changing from im­­portant rainfalls over the equatorial zone to an extreme aridity in the Sahara. Nor­thern Africa is the most water-stressed sub-­region, with less than one per cent of the renewable water resources of the continent for an area equivalent to 19 percent of Africa. The rainfalls are also impacting on the groundwater quantities, from which a lot of African countries are tightly depending. Groundwater is used for domestic and agricultural con­­sumption in many areas, particularly in arid sub-regions where surface water re­­sources are limited. However, areas heavily dependent on groundwater reserves are also at risk of water shortages, as water is extracted far more rapidly than it is recharged.


Efforts to provide adequate water re­­­sources for Africa will confront several challenges. Symptoms of physical water scarcity are showing up, evoking severe environmental degradation including river desiccation and pollution, declining gr­ound­water and water allocation where some groups win at the expense of others, raising the problem of conflict between and within nations.

Water availability and food security are elements ineluctably linked, hindering human wealth everywhere and are excep­­tionally critical in Africa. The productivity of agriculture depends significantly on the availability of water for irrigation. It has to be pointed out that purification and reuse of wastewater in combina­tion with efficient use of water is the only sustainable way to solve the water prob­­lem in water-scarce regions in Africa.

In the very recent few years, African govern­­ments, especially in the northern countries, started begging attention to the water issue; however, only a few actions have been taken yet, mainly due to the expensive technologies and knowledge transfer in the water treatment sector. The reuse of purified wastewater in agriculture and industry has strong potential to reduce stress on valuable fresh water resources in two ways, avoiding their pollution and reduction of their consumption. Trends over the past years in the construction of was­­te­­­water treatment technologies in Africa have been toward conventional wastewater treatment plants. However, devel­­­­oping countries cannot afford the high energy prices and operation costs of ad­­vanced and specialized systems, which require a trained and qualified staff as well. As a result, in most African regions the bulk of domestic and industrial waste­­water is finally discharged without any treatment or after primary treatment only, thus causing direct damages on health and environment. Traditional wastewater treatment techniques in Africa, when used, are far from optimising water puri­­fication. Reuse of water with such quality is impossible. This situation has motivat­ed experts and authorities to search for creative, efficient and environmentally sound ways to control water pollution. The development of simple, easy to ope­­r­ate and cost-effective biotechnological water treatment technologies is particu­­larly interesting for African countries. Bio­­technological methods are governed by plants or micro-organisms which can detoxify contaminants in water, soils, sedi­­ment, and sludge.

Current research in biotechnology is giv­ing new opportunities for sustainable waste­water treatment systems. Biotech­­nologies for wastewater treatment require relatively low capital investment when land is available at a reasonable price. They are easily maintained and they can han­dle uneven loads. All these features plus the ability to markedly reduce organic pollution, nutrients, and pathogen concentrations, have made these alterna­tives very attractive, particularly for rural communities.

Among the natural biological treatment systems available, the constructed wetlands treatment has been already im­­plemented in Africa and a considerable record of experience and design practice has been documented. Cons­­tructed wetlands are one of the most ef­­­ficient technologies for treatment of waste­­water with low pollution degree. Wetlands are being recognized as providing many benefits, including: food and habitat for wildlife; water quality improvement; flood protection; shoreline erosion control; and opportunities for recreation and aesthetic appreciation. The potential applications of wetland range from treatment of muni­­­cipal and various types of industrial waste­­water, to polishing of tertiary treated water and diffuse pollution. Wetlands signifi­­cantly reduce suspended solids, organic pollution, pathogens, heavy metals and excessive nutrients from wastewater.

Compared to conventional treatment sys­­­tems, constructed wetlands are low cost, easily operated and maintained, and have a strong potential for application in de­­­veloping countries, particularly by small rural communities. The pollution in such systems is removed through a combination of physical, chemical and bio­logical processes including sedimentation, precipitation, adsorption by soil particles, assimilation by plant tissue, and microbial transformation. Biological wastewater treatment in combination with mem­­brane separation (so-called membrane bioreactors, MBR) has figured out to be one of the most efficient treatment concepts. Membranes allow decoupling of pollutant’s retention time from hydrau­­lic retention time in the bioreactor, ena­­bling even biological degradation of pollu­­tants which are not biodegradable under normal circumstances. By proper choice of the membrane properties, the quality of the treated water can be tailored to the planned reuse application, for example for agricultural use concentrations of ni­­tro­­gen or phosphorus can be adjusted to the needs of the crops being irrigated. The most important advantage of MBR systems is a pathogen-free effluent. In­­novative MBR systems are furthermore characterised by energy consumption circa 2 kWh per m³ treated water, which is three to four times lower than the en­­ergy demand for seawater desalination. ttz Bremerhaven has successfully initia­­t­ed development of such technologies for applications in North Africa a few years ago (e.g. EU FP6 projects PURATREAT, www.puratreat.com).

However, many applications of biotechnology have not yet delivered practical solutions due mainly to the lack of information about the benefits of these technologies as well as the lack of dissemination of solutions adapted to local circumstances. WATERBIOTECH (Coor­di­na­tion and Support Action Project fund­ed by the EU in the 7th Framework Pro­­gramme, www.waterbiotech.eu) is an ini­­­­­­­tiative that will cope with water scarcity in Africa by providing access to relevant stakeholders in Western, Eastern and Nor­­th­­ern Africa to know-how in biotechnol­ogies, good practices and management solutions adapted to their local condi­tions for the sustainable management of polluted water resources. The targeted countries of WATERBIOTECH will be Tuni­­sia, Algeria, Morocco, Egypt, Senegal, Burkina Faso, Ghana and Saudi Arabia.
The idea is to disseminate best practices jointly with all the requirements and the strategy necessary for the implementa­tion of selected biotechnologies specifically assigned to local regions within the targeted countries. Relevant actors that will benefit from this action will be farmers, providers of sewage treatment services, authorities and decision makers, specialized scientific communities, local com­­munities, and general public who live in water-stressed areas.

The integrated approach of WATERBIOTECH takes into consideration that different as­­­pects influence the availability of water resources and only a holistic vision can provide effective solutions to enhance water management in African countries. Environ­­­­mental and health concerns, as well as socio-economic aspects such as hou­­se­­holds income, water consumption patterns, irrigation methods or interests in water resources of different stakeholders must be taken into account in the proposal of solutions. WATERBIOTECH outputs will enhance the decision making process by providing guidelines and materials that support stakeholders to implement cost-­effective and sustainable solutions adap­­t­­ed to the reality in their regions.


ttz Bremerhaven is an independent pro­­vider of research services and operates in the field of application-oriented re­­­search and development. Under the um­­­brella of ttz Bremerhaven, an internation­al team of experts is working in the areas of food, environment and health. The En­­vironment Department at ttz Bremer­haven performs applied research and de­­velopment in the areas of “Water, Energy and Land Use Management” around the globe. Innovative ideas from the fields of energy efficiency, renewable energies, water and wastewater treatment, aquaculture, sustainable landscape and re­­source management are developed, real­­ized and introduced into the market in cooperation with enterprises, associations and research partners. Over the last five years, the Environment Depart­­ment at ttz Bremerhaven has participat­ed in over 250 national and international projects or coordinated them.

For more than seven years ttz Bremer­­haven has been successfully cooperating with re­­search institutions as well as national and private water treatment institutions in Tunisia such as Centre de Bio­tech­nologie de Sfax, Centre International des Technologies de l’Environnement de Tunis, Centre de Recherches et des Techno­lo­gies des Eaux Soliman, ONAS – Office National de l’Assainissment, TESCO – Tunisian Engineering Services Com­pa­ny Tunis, etc. and acted as consultant to the GIZ site office in Tunisia in the field of valorization of agro-industrial residues.Africa’s water resources are limited, mainly depending on climate factors, essentially rainfalls and weather. Even the ex­­­isting and available quantities of water are generally subject of low quality af­­­fecting people’s health and negatively im­­pacting on agriculture.


Schories_09-KopieThe author was born in 1964 and studied General Process Engineering, receiving his doctorate in 1999 at the TU Claus­­thal. Bio­­­logical waste treatment and water manage­­ment are the core activities of his job. Dr.-Ing. Schories has been working for ttz Bremerhaven since 2001 and has been the Technical Director of the En­­vironmental Institute since 2005. Further­­­more, he has been a lecturer at the Bremer­­haven Univer­sity of Applied Sciences since 2012.