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WET COFFEE PROCESSING WASTE MANAGEMENT PRACTICE IN ETHIOPIA

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ARTICLE INFO ABSTRACT Coffee is one of the most important agriculture commodities in the world. Ethiopia had been the origin of coffee because coffee plant was initially found and cultivated in the Kaffa province. Due to the great demand of coffee, large amounts of residues are generated in the coffee industry, which are toxic and represent serious environmental problems. 100 kg of fresh berry gives about 40 kg of wet waste pulp. Coffee pulp contains caffeine, tannins, polyphenols and organic solid residues. It shows toxic nature and thus not been utilized beneficially. This effluent is being directly discharged to the nearby water bodies causing severe ailments like overexcitement, skin irritation, stomach pain, nausea and breathing problem. Severeness of this waste causes a serious environmental problem among the residents of nearby area. For this reason, efforts have been made to develop methods for coffee waste treatment and management, also its utilization as a raw material for the production of bio energy is emerging as a new technology. Recently, some attempts have been made to use these residues for energy or value-added compounds production as strategies to reduce their toxicity levels. The present article provides an overview regarding coffee and its main industrial residues. Based on the data, it was concluded that coffee may be considered as one of the most valuable primary products in world trade, crucial to the economies and politics of many developing countries since its cultivation, processing, trading, transportation, and marketing provide employment for millions of people. As a consequence of this big market, the reuse of the main coffee industry residues is of significant importance from environmental and economical viewpoints.
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RESEARCH ARTICLE
WET COFFEE PROCESSING WASTE MANAGEMENT PRACTICE IN ETHIOPIA
1*Asrat Gebremariam Woldesenbet, 1Belay Woldeyes and 2Bhagwan Singh Chandravanshi
1School of Chemical and Bio-Engineering, Addis Ababa Institute of Technology, Addis Ababa University,
P.O. Box 385, Addis Ababa, Ethiopia
2Department of Chemistry, Faculty of Sciences, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia
ARTICLE INFO ABSTRACT
Coffee is one of the most important agriculture commodities in the world. Ethiopia had been the origin
of coffee because coffee plant was initially found and cultivated in the Kaffa province. Due to the great
demand of coffee, large amounts of residues are generated in the coffee industry, which are toxic and
represent serious environmental problems. 100 kg of fresh berry gives about 40 kg of wet waste pulp.
Coffee pulp contains caffeine, tannins, polyphenols and organic solid residues. It shows toxic nature
and thus not been utilized beneficially. This effluent is being directly discharged to the nearby water
bodies causing severe ailments like overexcitement, skin irritation, stomach pain, nausea and breathing
problem. Severeness of this waste causes a serious environmental problem among the residents of
nearby area. For this reason, efforts have been made to develop methods for coffee waste treatment and
management, also its utilization as a raw material for the production of bio energy is emerging as a new
technology. Recently, some attempts have been made to use these residues for energy or value-added
compounds production as strategies to reduce their toxicity levels. The present article provides an
overview regarding coffee and its main industrial residues. Based on the data, it was concluded that
coffee may be considered as one of the most valuable primary products in world trade, crucial to the
economies and politics of many developing countries since its cultivation, processing, trading,
transportation, and marketing provide employment for millions of people. As a consequence of this big
market, the reuse of the main coffee industry residues is of significant importance from environmental
and economical viewpoints.
Copyright © 2015 Asrat Gebremariam Woldesenbet et al. This is an open access article distributed under the Creative Commons Attribution License, which
permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
INTRODUCTION
Coffee is one of the most important agricultural export
commodities in the world economy, next to oils and it is the
most important and strategic commodity on which Ethiopia's
economy depends on. It has always been the most important
cash crop and largest export commodity, which account 90%
of exports and 80% of total employment in Ethiopia (Addis
Ababa, 2008). Ethiopia had been the origin of coffee since
coffee plant was initially found and cultivated in the Kaffa
province (Bonga, Makira) of Ethiopia (UNCTAD/WTO,
2002). Coffee in Ethiopia contributes 41% of the country’s
total foreign exchange earnings and about 10% of the gross
domestic product. Over 25% of the populations of Ethiopia are
dependent on coffee for their livelihoods. There are four types
of coffee production system in Ethiopia: forest coffee (10%),
semi-forest coffee (35%), garden coffee (35%), and plantation
coffee (20%) (5% government, 15% private) (Addis Ababa,
*Corresponding author: Asrat Gebremariam Woldesenbet
School of Chemical and Bio-Engineering, Addis Ababa Institute of
Technology, Addis Ababa University, P.O. Box 385, Addis Ababa,
Ethiopia
2008). Coffee contains over 1500 chemical substances, 850
volatile and 700 soluble, and when prepared correctly involves
13 independent chemical and physical variables. When coffee
is extracted in water, most of the hydrophobic compounds,
including oils, lipids, triglycerides, and fatty acids remain in
the grounds, as do insoluble carbohydrates like cellulose and
various indigestible sugars. Structural lignin, protective
phenolics and the wonderful aroma-producing essential oils
are also present in coffee. Coffee is a major plantation crop
grown worldwide and is one of the most popular beverages
consumed throughout the world. There are three common
species of coffee: robusta, arabica and liberica. 75-80% of the
coffee produced worldwide is Arabica and 20% is Robusta.
Residues Generated in the Coffee Industry
The agro-industrial and the food sectors produce large
quantities of waste, both liquid and solid. Due to the great
demand of coffee, coffee industries are responsible for the
generation of large amount of residues, which are toxic and
represent serious environmental problems (Solange et al.,
2011).
ISSN: 0976-3376
Asian Journal of Science and Technology
Vol. 6, Issue 05, pp. 1467-1471, May, 2015
Available Online at http://www.journalajst.com
ASIAN JOURNAL OF
SCIENCE AND TECHNOLOGY
Article History:
Received 15th February, 2015
Received in revised form
24th March, 2015
Accepted 02nd April, 2015
Published online 31
st
May, 2015
Key words:
Wet Processing,
Coffee Effluent,
Waste Pulp,
Pollution,
Waste Utilization
Table 1. Africa: Coffee production (Average in thousand bags of
60 kg each)
Year 1980 - 89 1990 - 99 2000 - 09 2010 -12
Total Africa 19888 16078 15372 15712
Ethiopia 3128 2973 4904 6450
Uganda 2724 2811 2924 3002
Cote d'ivoire 4338 3448 2692 1291
Cameroon 1771 1022 821 845
Tanzania 875 779 796 686
Congo, D.R. 1610 1019 383 681
Kenya 1726 1377 766 669
Madagascar 1092 780 490 566
Others 2625 1868 1597 1522
The wastewater generated from coffee processing plant
contains organic matter like pectin, proteins, and sugars
(Bello-Mendoza and Castillo-Rivera, 1998). Coffee pulp, one
of the principal by-products of wet processed coffee
constitutes almost 40% of the wet weight of the coffee berry,
is rich in carbohydrates, proteins, amino acids, poly-phenols,
minerals, and appreciable quantities of tannins, caffeine and
potassium. The poly-phenols and caffeine are reported to be
the anti-physiological factors on animal feed. Hence, coffee
pulp has to follow a preliminary treatment before it is used
(Sebastianos et al., 1998). Coffee pulp is generated to the
extent of 40% in the fermentation of coffee berries poses many
problems in the coffee producing countries. Its disposal in
nature, without any treatment, causes severe environmental
pollution due to putrefaction of organic matter.
Coffee Industry Residues Applications
Nowadays, there is great political and social pressure to reduce
the pollution arising from industrial activities. Almost all
developed and underdeveloped countries are trying to adapt to
this reality by modifying their processes so that their residues
can be recycled. Consequently, most major companies no
longer consider residues as waste, but as a raw material for
other processes (Mussatto et al., 2006).
The presence of organic material and its demand of great
quantities of oxygen to degrade confer a toxic nature. Despite
the negative characteristic and the large amounts that they are
generated, there are few studies focusing on their use in
different and profitable applications. Besides to add value to
these unused materials, finding alternative forms to use them
would be useful to decrease their impact to the environment
(Solange et al., 2011).
Processing of Coffee
There are two ways by which coffee can be processed: wet
(fermented and washed) and dry (natural) processing. In most
Source: (International Coffee Organization, 2014)
Fig. 1. Percent (%) share of Africa and Ethiopia in World coffee production (International Coffee Organization, 2014)
Fig. 2. Harvesting coffee for wet processing
1468 Asian Journal of Science and Technology Vol. 6, Issue 05, pp. 1467-1471, May, 2015
cases, wet processing is regarded as producing a higher quality
product.
Wet Method
Approximately half of the world coffee harvest is processed by
the wet method in which the coffee berry is subjected to
mechanical and biological operation in order to separate the
bean or seed from the exocarp (skin), mesocarp (mucilagenous
pulp) and the endocarp (parchment) (Clark, 1985). Pulp
represents about 40% of the weight of the fresh fruit and
presently is underutilized, causing serious pollution problems.
In wet method, the de-pulping involves the removal of the
outer red skin (exocarp) and the white fleshy pulp (mesocarp)
and the separation of the pulp and beans. Immature cherries
are hard and green and very difficult to de-pulp. If the coffee is
to be wet processed, correct harvesting is essential. For small-
scale units, the cherries can be de-pulped in a pestle and
mortar, and is very labor intensive.
Dry Method
In dry method, the coffee cherries are dried immediately after
harvest. This is usually sun drying on a clean dry floor or on
mats. The bed depth is less than 40 mm and the cherries are
raked frequently to prevent fermentation or discoloration.
However, there are problems associated with this method. The
most serious problem is dust and dirt blown onto the product.
Another problem is rainstorms often appear (even in the dry
season) with very little or no warning. This can soak the
product very quickly. Labor has to be employed to prevent
damage or theft. Sun drying is therefore not recommended.
The dried cherry is then hulled to remove the pericarp. This
can be done by hand using a pestle and mortar or in a
mechanical huller. The mechanical hullers usually consist of a
steel screw, the pitch of which increases as it approaches the
outlet so removing the pericarp.
Fig. 3. Sun drying of coffee for dry process
Problems of Coffee Waste
Agro-industrial residues/wastes are generated in large
quantities throughout the world. Their non-utilization results in
loss of valuable nutrients and environmental pollution.
Fig. 4. Waste disposal
The better utilization by biotechnological means assumes
social, economic and industrial importance. The wastewater
from agro industries has high concentration of organic
pollutants. So it’s very harmful for surrounding water bodies,
human health and aquatic life if discharged directly into the
surface waters. People residing in the vicinity of agro
industries utilizing the stream water for domestic purposes
suffer from severe health problems (Alemayehu and Rani,
2008). The seriousness of the situation is shown in Table 2.
From this it is obvious that some people were suffering from
one problem while others were having cumulative health
effects. Agricultural practices such as use of organic
herbicides, inorganic and synthetic pesticides, efficiency of the
uses of inorganic fertilizers, etc., determines the environmental
issues arising from them. For instance, the use of agricultural
pesticides significantly changes the toxic characteristics of the
wastewater (Chanakya and Dealwis, 2004).
Table 2. Health problems reported by the population living
nearby industries (Alemayehu and Rani, 2008)
Health problems % of population affected
Spinning sensation (feeling drunk) 89
Eye irritation (burning inside) 32
Skin irritation 85
Stomach problem 42
Breathing problem 75
Nausea 25
1469 Asian Journal of Science and Technology Vol. 6, Issue 05, pp. 1467-1471, May, 2015
Coffee pulp/husk contains some amount of caffeine and
tannins, which makes it toxic resulting in disposal problem.
However, it is rich in organic matters, which makes it an ideal
substrate for microbial processes for the production of value-
added products. Several solutions and alternative uses of the
coffee pulp and husk have been attempted. These include
fertilizers, livestock feed, compost, etc.
Management of Coffee Waste
Having known the problems of coffee waste, several attempts
have been made to manage. Coffee pulp solid waste is being
converted into compost, which was used by the suppliers in
fertilizing their coffee farms. Waste water management
techniques used by the coffee pulping operators are based on
the use of lagoons.
Table 3. Characteristics of effluent wastewater from conventional
wet coffee processing plants
Parameter Mean + SD discharge standard (Ethiopia EPA)
pH 4.13 + 0.23 6-9
BOD
mg/L 1697 + 391 80
COD mg/L 5683+ 304 250
NH
mg/L
4.51 + 1.62 5
NO
N mg/L 3.39 + 0.65 20
PO
mg/L
3.32 + 0.5 5
TSS mg/L 1975 + 322 100
TDS mg/L 1801 + 245 3000
DO mg/L 2.14 + 0.72 -
Source: (Tsigereda et al., 2013)
Environmental Issues
The coffee process has been causing environmental problems
at the local level not only due to the consumption of water, but
more due to the discharge of effluents with large volumes of
organic waste. Pollutants in coffee wastewater emerge from
the organic matter set free during pulping, especially due to
the difficulty in degrading the mucilage layer surrounding the
beans. The organic and acetic acids from the fermentation of
the sugars make the wastewater very acidic (with pH as low as
3.8), a condition in which higher plants and animals can hardly
survive. Moreover, the total suspended solids in the effluents
are high; in particular, the digested mucilage, when
precipitated out of the solution, builds a crust on the surface,
clogging up waterways and further contributing to the
anaerobic conditions.
Table 4. Composition of coffee waste
Pulp Mucilllage
Contents Proportion
(%) Contents Proportion
(%)
Ether extract 0.48 Water 84.2
Crude fiber 21.4 Protein 8.00
Crude protein 10.1 Reducing sugar 2.50
Ash 1.50 Non-reducing sugar 1.60
Nitrogen free extract 31.3 Pectin 1.00
Tannins 7.80 Ash 0.70
Pectic substances 6.50
Non-reducing sugars 2.00
Reducing sugars 12.4
Chlorogenic acid 2.60
Caffeine 2.30
Total caffeic acid 1.60
In addition, the presence of some toxic chemicals alkaloids,
tannins, and poly-phenolics makes the environment for
biological degradation of organic material in the wastewater
more difficult. The main ecological effect of organic pollution
in a water course (into which effluents have been discharged)
is the decrease in oxygen content. The organic substances
diluted in the wastewater break down very slowly by
microbiological processes, using up oxygen from the water.
Due to the decrease in oxygen content, the demand for oxygen
to break down organic material in the wastewater exceeds the
supply, dissolved in the water, thus creating anaerobic
conditions.
The amount of oxygen needed to biologically break down
organic wastes diluted in water (BOD) could be as high as
15,000 mg/l, while the amount of dissolved oxygen required to
combine with chemicals in the wastewater (COD), could be
between 15,000 and 25,000 mg/l. The resulting anaerobic
conditions can be fatal to aquatic creatures and also cause bad
odour; moreover, the bacteria cause health problems if the
wastewater seeps into a source of potable water. Another
environmental problem is the high requirement of water for
coffee processing; as much as 15,000 litres per tonne of
cherries (coffee fruit) can be used, if there is no recycling and
reuse (UNCTAD/WTO, 2002). In Ethiopia at present, there
are more than 1026 wet coffee processing installations
processing 1000 tons of coffee cherry daily on average and a
number of industries under construction. About 15 liters of
water is required to recover 1 kg of clean green coffee beans.
The effluents from the processing industries are directly
discharged to the river streams. Waste water from pulping,
fermentation and washing of coffee beans presents series
problem on receiving environment especially on water bodies.
Conclusion
In coffee producing countries, coffee waste constitutes a
source of severe contamination and serious environmental
problems. For this reason, since the middle of the last century,
efforts have been made to develop methods for coffee waste
treatment and management, also its utilization as a raw
material for the production of feed, beverages, vinegar, biogas,
caffeine, pectin, peptic enzyme, protein, and compost. Hence,
there is a need to curb these problems through innovative and
eco-friendly techniques. So, this documentation may be an eye
opening for the area. Presently, coffee waste management
systems in Ethiopia are not operating. They could reduce on
their losses if they employ qualified staff and adopt modern
management techniques. Therefore, unless they improve their
profitability, they will consider demands to take an additional
investments, e.g. for environment as a burden. Many by-
products from wet coffee processing offer additional sources
of revenue, employment and new enterprises. It is therefore
high time that coffee waste started to put a price.
Acknowledgements
The authors are thankful to School of Chemical and Bio-
engineering at Addis Ababa Institute of Technology, AAU for
financial, technical support and laboratory facility during the
research work. Asrat Gebremariam Woldesenbet would like to
thank Bonga College of Teacher Education for providing
sponsorship for his PhD study.
1470 Asian Journal of Science and Technology Vol. 6, Issue 05, pp. 1467-1471, May, 2015
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1471 Asian Journal of Science and Technology Vol. 6, Issue 05, pp. 1467-1471, May, 2015
... The environmental impact of agricultural waste from the processing of food and feed crops is an increasing concern worldwide. Concerted efforts are underway to develop sustainable practices for the disposal of residues from the processing of such as coffee, sugarcane and corn (Woldesenbet et al., 2015). Coffee (Coffea arabica L) is one of the most important agriculture export commodities in the world economy, next to oils and the most popular beverages, consumed by millions of people every day. ...
... On the other hand due to the great demand of coffee, large amounts of residues are generated in the coffee industry which are toxic and represent serious environmental problems. 100 kg of fresh berry gives about 40 kg of wet waste pulp (Woldesenbet et al., 2015). In countries like Ethiopia, a large amount of coffee husk (about 258,000 t) is generated annually and it is not always properly disposed of or reutilized (Asfaw et al., 2019). ...
... The effluents from the processing industries are directly discharged to the rivers and streams. Wastewater from pulping, fermentation and washing of coffee beans presents series problem on receiving environment especially on water bodies (Woldesenbet et al., 2015). Due to the great demand, coffee industries are responsible for the generation of large amount of residues, which are toxic and represent serious environmental problems . ...
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Coffee processing wastewater (CPW) is a highly polluted industrial wastewater that can be detrimental to the environment when it is discharged into a watercourse without treatment. The present study looks at the performance of a strong acid cation exchange resin and a strong base anion exchange on the removal of chemical oxygen demand (COD), colour, and ammoniacal nitrogen (NH 3-N) from CPW using batch experiment. The experiments were carried out with varying pH, resin dosage (g), contact time (min), temperature (°C), and shaking speed (rpm). It was observed that over 70% reduction of NH 3-N was achieved under optimal conditions by cation exchange resin, while more than 70% COD, 60% colour removal was attained by anion exchange resin. Langmuir, Freundlich, and Brunauer-Emmett-Teller isotherm models were applied to determine the COD, colour and NH 3-N removal behaviour from CPW using cationic and anionic resins. The findings revealed that the Langmuir equation was the best-described isotherm model for removing COD, colour and NH 3-N from CPW using both cationic and anionic resins. The kinetic study showed that the removal of COD, colour, and NH 3-N was well-fitted with the pseudo second order kinetic model. Furthermore, it was observed that the diffusion was the rate-controlling process. The determination of the thermodynamic properties analyses showed that the COD, colour and NH 3-N removal from CPW using cationic and anionic resins was spontaneous and endothermic. The study suggests that both ion exchangers could reduce the concentration of pollutants in the coffee processing wastewater.
... The coffee processing industries uses large quantity of water (an average of 147m3/day) for pulping, fermentation and washing of the coffee cherry with no recirculation (Tekle et al., 2015). For wet processed coffee (the most popular type in Ethiopia), about 5-15 litres of water are required to recover 1 kg of clean green coffee beans (the actual volume of water used depends on the pulping process, fermentation intensity and coffee bean transportation volume) (Haadis and Rani, 2008;Woldesenbet, Woldeyes and Chandravanshi, 2014;Woldesenbet et al., 2015). Similarly, Olani (2018) indicates that about 10-20 litres of water are required to process 1kg of coffee beans in Ethiopia. ...
Technical Report
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Agriculture remains the most significant sector in the African economy as it contributes around 15% to its total Gross Domestic Product on an average (GDP; OECD/FAO, 2016). It provides employment to around 60% of the workforce and is able to feed half of the population with the remaining half of the food demand met by imports. Growing demand for food due to the increasing population in sub-Saharan Africa (SSA) is one of the key challenges for agriculture. It is estimated that global population numbers will rise to about 9.7 billion by 2050 and about 1.3 billion will add to the existing African population. This will put enormous pressure on agriculture and food systems to respond in order to meet the food demand, reduce food imports and protect natural resources. At the same time, it provides an opportunity for African agriculture to respond more cohesively and improve value generated by this sector to society, the environment and the economy. This can help achieve self- sufficiency in food, increased employment to meet the needs of the growing workforce, and the protection of natural resources while contributing to the Sustainable Development Goals (SDGs). A comprehensive action plan with carefully developed policies is required to achieve these outcomes. It is recognised that the global agriculture and food systems cause damages to the environment and human health. However, these are not captured by the current economic system, leading to perverse and pervasive outcomes for society and the environment. Therefore, this report aims to consider all social and environmental externalities – both negative and positive, in sub-Saharan African agriculture and food systems. Its goal is to reflect these in the economic system by evaluating comprehensive costs and benefits through an innovative, universal, and inclusive framework, the ‘TEEBAgriFood’ framework. This assessment intends to stimulate appropriate policy responses for sustainable agriculture and food systems to be developed and ensure food and nutritional security as well as economic prosperity for all in Africa. The report provides a regional analysis and narrative on the economics of the agriculture and food sector by focusing on Sub-Saharan Africa, highlighting the key positive and negative externalities it generates and the national and international policy context. These externalities are assessed with the TEEBAgriFood Evaluation Framework in three case studies: agroforestry (coffee/cocoa) in Ethiopia and Ghana, livestock in Tanzania, and rice in Senegal. Cocoa (Ghana) and coffee (Ethiopia) in Agroforestry systems This study quantifies the biophysical and social impacts and dependencies along the cocoa and coffee value chains in Ghana and Ethiopia, respectively (ICRAF, 2019). Its aim is to assess key negative and positive impacts to health, ecosystems and the economy of the processes associated with the value chains of the two commodity crops. This is achieved by applying the TEEB for agriculture and food (TEEBAgriFood) framework (TEEB, 2018). Following this framework, several invisible and visible benefits and costs within these value chains are identified, quantified, monetised and /or described. Most of these benefits and costs are represented in monetary values except for biodiversity, vegetative diversity and aquatic life diversity which were measured using diversity indices such as the Shannon-H index, the Simpsons index, the species richness index, or the Alpha index. Secondary data sourced from viii a variety of sources including peer reviewed journal articles and technical reports was used in the analysis. Livestock systems in Tanzania This study quantifies socio-economic and ecological externalities of value chain activities related to three livestock sectors in Tanzania using the TEEBAgriFood evaluation framework: the Pastoralist cattle system, the Backyard poultry system, and the Smallholder dairy system. The livestock described here has local value chains which are also examined in each case. Different actors exist in the pastoralists’ cattle value chain in the Arusha region. The major actors in the chain are producers (farmers), middlemen, traders, abattoirs, butchers, supermarkets, hotels and individual consumers (final consumers). However, middlemen dominate the market and are reported to be the major means of market information. Backyard poultry production in Tanzania is a traditional sector at the smallholder level and has an important position in the rural household economy, supplying high quality meat and eggs, as well as increasing income for rural farmers. Most of the milk produced originates from the traditional small holder dairy system, comprised of over 90% of the cattle population, and is consumed at household level. Only about 3% of the milk is filtered through to the formal market. Rice in Senegal The rice sector in Senegal is facing the strong imperative of increasing the domestic production and processing of rice. Several substantial donors have suggested that investment should be made in the rice sector. However, there are a number of alternative pathways leading towards that goal. For example, increasing rice production through conventional high- input methods could ramp up yields, but there are rising costs related to increased fertilizer, pesticide and water use. Large-scale rice value chain projects may propose equally large rice mills, but the opportunity to process rice in smaller units may enable greater use of rice by- products such as livestock feed and promote greater equity through community ownership. Different pathways have different implications for employment in the agriculture and food sector. By using a holistic framework to review the possible pathways, many diverse aspects can be brought into focus at the same time, looking at impacts on not just economic or produced capital but also social, human and natural capital. The application of the TEEBAgriFood framework and system modelling has shown that alternative systems based on FAO’s principles of agroecology can guide the further development of rice policies in Senegal and provide insights into policy opportunities and recommendations for capturing externalities into decision-making for better livelihood outcomes. Three case studies clearly examine the key aspects of the value chains of coffee, cocoa, livestock, and rice. This analysis also recommends alternative systems and scenarios for policy makers to consider in their respective countries. For example, shaded coffee and cocoa systems promote several public benefits and can be incentivised through markets and by government-provided subsidies. Livestock systems in Tanzania provide food for millions of rural dwellers and need further support through training and quality inputs in order to realise their full potential. Rice in Senegal can be produced by using the principles of agroecology, thereby saving inputs cost. These savings can then be provided directly to farmers and the ix R&D sector to support these multi-dimensional farming systems. Such approaches can lead to the development of self-sufficient systems in these countries. Further analysis is required at the continental scale, including key cereal crops that are essential for food security in SSA, in order to generate evidence to shift agriculture and food policies towards long term sustainability, the achievement of the SDGs and well-being for all. Recommendations Based on the analysis presented in earlier sections, some recommendations are suggested below. • Subsidies for inputs can be carefully investigated to target desired outcomes for society rather than the narrow focus of per hectare productivity. • FDI can be further channelled to invest in infrastructure required to support the agriculture sector such as roads, ports, storage, transport, finance, processing, and regulated markets. • Extension services can be further improved by including training about the multidimensional aspects of farming and the move away from per ha productivity. • There is a need to improve HDI by investing in education, children and women’s health, and environmental sustainability for society to be healthy, better educated and capable of making informed decisions about food. • The R&D sector needs investment and reforms. The current global agriculture system is geared towards a single, narrow focus that has to change. This research should trickle down to the African continent and SSA regions to transform agriculture and food systems. • Agriculture is vital for 9 out of 17 SDGs and is a prominent sector in Africa’s Agenda 2063. It therefore needs further attention from policy makers in terms of investment and national and regional policies. • There is a need to: o Identify change agents to bring this transformation. o Increase production in a more sustainable manner while absorbing a growing labour force. o Promote diversification based on high quality processed products. o Promote efficient and more equitable value chains. o Make farms and agricultural systems more resilient. o Develop regional markets and control international integration. o Design and implement structural policies and instruments. o Reform development aid aimed at facilitating the structural reform process. o Clearly articulate the objective and a shared vision.
... Meanwhile, the use of two and more microorganisms gives several benefits than conventional pure culture fermentation [3]. Thus, Pseudomonas fluorescence and Escherichia coli bacteria in the treatment have degraded organic and less residual effect on the environment [4]. In Ethiopia, coffee processing industries are sources of contamina-tion to water bodies, which creates environmental pollution [5]. ...
Article
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Effluents from wet processing of coffee industries pollute water bodies since the wastewater is released to the water bodies' vicinity. The wastes water from these industries affects the surface and groundwater. The study was initiated to treat wastewater effluent coming from the coffee industry in the specific area by using an anaerobic mixed culture of Pseudomonas fluorescence and Escherichia coli bacteria. The treatment reduced BOD5, COD, and TS from its initial concentration of 320.26 mg/l, 1261 mg/l, and 3545 mg/l to 58.37 mg/l, 152 mg/l, and 1198 mg/l, respectively. The study's treatment had reduced the BOD5 load up to 81.67%, the COD load up to 87.94%, and TS load up to 33.79% from the initial load using optimization of the treatment method. Therefore, it can be concluded that mixed culture bacteria of P. fluorescence and E. coli as a new effective treatment having the potential for BOD5, COD, and TS reduction from the effluent. The mixed culture of microorganisms can reduce the contaminants that made the approach cost-effective, time-saving compared with other results found by other studies without mixed culture. The microorganisms included in the study can be applied for the treatment of effluent containing multiple contaminants.
... www.ijsrp.org cent of exports and 80 per cent of total jobs [3]. Coffee quality directly influences coffee farmers' prices because when coffee quality is high, coffee prices are also high and vice versa [1]. ...
Article
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El beneficio húmedo del café demanda grandes cantidades de agua, además de generar mucílago y pulpa que se integran a las aguas superficiales. El objetivo de esta investigación fue analizar las propiedades físicas y químicas del agua de río Cuxtepec, río Cabañas y su principal afluente, ubicado en La Concordia, Chiapas, México. En estas aguas son descargados los subproductos derivados del beneficiado húmedo del café durante el periodo de cosecha. Los sitios de muestreo fueron arroyo San Pedro, río Cabañas, ranchería 30 de Agosto y río Cuxtepec, las muestras de agua se obtuvieron durante octubre y diciembre 2016; enero, abril y junio 2017. Se determinó pH, conductividad eléctrica (CE), sólidos disueltos totales (SDT), sólidos suspendidos totales (SST), sólidos sedimentables (SS), demanda química de oxígeno (DQO), demanda bioquímica de oxígeno (DBO), nitrógeno total (NT), amonio(NH4+), nitritos (NO2‾), nitratos (NO3‾) como N, fósforo total (PT), dureza del agua (DA), temperatura del agua (TA) y la temperatura ambiental (T. Amb). El contenido de DQO y DBO varió de un sitio a otro, con valores máximos entre 7.7 y 1.25 mg L-1, respectivamente. Esta baja concentración permitió altos contenidos de oxígeno al nivel de 7.99 mg L-1. Asimismo, la carga de SDT fue de 149.7 mg L-1 y pH de 8.9, estas son condiciones favorables para la vida acuática. En general, los valores medidos en corrientes aguas abajo a las plantas tradicionales del procesamiento húmedo de café no presentaron niveles que indiquen riesgos para los usos del agua en actividades agrícolas, pecuarias y consumo humano en las áreas cercanas a los cuerpos de agua. Estos hallazgos plantean la necesidad de establecer un sistema de monitoreo de los contaminantes señalados en la zona cafetalera de Chiapas, para mejorar el manejo ecológico de las aguas residuales provenientes del beneficiado húmedo del café.
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This study examined the effluent suitability for discharge of newly emerged advanced wet coffee processing technologies compared to the conventional systems; near Jimma, Ethiopia. A descriptive study design was employed and composite samples were analyzed in triplicate for selected physicochemical parameters (COD, BOD5, D O , N H 3 , PO4 3-, NO3-N, pH, TSS, TDS, conductivity, and turbidity). Consequently, the mean results obtained from conventional wet coffee processing technologies effluent wastewater were BOD5 (1697 mg/L), COD (5682.5 mg/L), TSS (1975 mg/L), TDS (1800.75 mg/L), and pH (4.13). Whereas mean values from effluent wastewater of advanced wet coffee processing technologies were BOD5 (2687 mg/L), COD (3567 mg/L), pH (6.69), and TSS (282.42). Even though there was significant variation between conventional and advanced wet coffee processing effluent wastewater; both wet coffee processing technologies did not comply with Ethiopian permissible discharges limit standards for BOD5, COD and TSS. Hence, establishing advanced wet coffee processing technologies does not seem to solve the pollution problems associated with coffee processing. Therefore, effluent wastewater treatment systems are needed for both technologies before discharging to prevent surface water pollution.
Article
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Coffee is one of the most consumed beverages in the world and is the second largest traded commodity after petroleum. Due to the great demand of this product, large amounts of residues are generated in the coffee industry, which are toxic and represent serious environmental problems. Coffee silverskin and spent coffee grounds are the main coffee industry residues, obtained during the beans roasting, and the process to prepare “instant coffee”, respectively. Recently, some attempts have been made to use these residues for energy or value-added compounds production, as strategies to reduce their toxicity levels, while adding value to them. The present article provides an overview regarding coffee and its main industrial residues. In a first part, the composition of beans and their processing, as well as data about the coffee world production and exportation, are presented. In the sequence, the characteristics, chemical composition, and application of the main coffee industry residues are reviewed. Based on these data, it was concluded that coffee may be considered as one of the most valuable primary products in world trade, crucial to the economies and politics of many developing countries since its cultivation, processing, trading, transportation, and marketing provide employment for millions of people. As a consequence of this big market, the reuse of the main coffee industry residues is of large importance from environmental and economical viewpoints. KeywordsCoffee–Silverskin–Spent grounds–Cellulose–Hemicellulose
Article
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The objective of this study was to assess the effect of wastewater produced from coffee processing plant on nearby water bodies and human health. A study was conducted around the coffee processing plant in Zimma zone (Ethiopia) to assess the physico-chemical characteristics of effluent generated from this plant. Analysis of the water samples taken from the surrounding water bodies had also been done. It was found, from the present investigation, that the wastewater from coffee processing plant was heavily polluted with organic matter as it showed high concentration of COD (upstream 25,600mg/l and downstream 15,780mg/l), BOD (upstream 14,200mg/l and downstream 10,800mg/l), phosphate (upstream 7.3mg/l and downstream 4.6mg/l), nitrate (upstream 23mg/l and downstream 10.5mg/l) and suspended solids (upstream 5870mg/l and downstream 2080mg/l) and these concentrations were much higher than the permissible limits prescribed by WHO. It was also found, from this study, that the people residing in the vicinity of this plant were consuming this polluted water and as a result suffered from many diseases like skin irritation, stomach problem, nausea and breathing problem.
Article
The paper examines the broader environmental issues and environmental management aspects of primary coffee processing in general and more specifically how it is addressed in India. Primary processing, the production of green beans from the coffee fruits, is practised to bring out more flavour. Coffee is an important global commodity, yet seen from a systemic view the producers and consumers of such an important commercial commodity are far apart. Primary coffee processing, with all its attendant environment impact, takes place at the producer end. The consumers in general are unaware of these impacts. The various methods of processing, the processing steps and the waste discharge associated with them are reviewed. A review of pollution and associated management methods is presented. An anaerobic bioreactor design developed and tested in a few Indian coffee plantations as a simple solution is also described.
Article
Brewers' spent grain (BSG) is the major by-product of the brewing industry, representing around 85% of the total by-products generated. BSG is a lignocellulosic material containing about 17% cellulose, 28% non-cellulosic polysaccharides, chiefly arabinoxylans, and 28% lignin. BSG is available in large quantities throughout the year, but its main application has been limited to animal feeding. Nevertheless, due to its high content of protein and fibre (around 20 and 70% dry basis, respectively), it can also serve as an attractive adjunct in human nutrition. Recently, attempts have been made to use BSG in biotechnological processes, such as in cultivation of mushrooms and actinobacteria, as a source of value-added products, such as, ferulic and p-coumaric acids, xylose, arabinose, or as raw material for xylitol and arabitol production. The main characteristics and potential applications of BSG are reviewed focussing on these alternative uses of this agro-industrial by-product as a raw material in foods, in energy production and in biotechnological processes.
Article
The ability of an anaerobic hybrid reactor, treating coffee wastewater, to achieve a quick start-up was tested at pilot scale. The unacclimatized seed sludge used showed a low specific methanogenic activity of 26.47 g CH4 as chemical oxygen demand (COD)/kg volatile suspended solids (VSS) x day. This strongly limited the reactor performance. After a few days of operation, a COD removal of 77.2% was obtained at an organic loading rate (OLR) of 1.89 kg COD/m3 x day and a hydraulic retention time (HRT) of 22 h. However, suddenly increasing OLR above 2.4 kg COD/m3 x day resulted in a deterioration in treatment efficiency. The reactor recovered from shock loads after shutdowns of 1 week. The hybrid design of the anaerobic reactor prevented the biomass from washing-out but gas clogging in the packing material was also observed. Wide variations in wastewater strength and flow rates prevented stable reactor operation in the short period of the study.
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