Incineration is a thermal process that transforms medical wastes into inorganic, incombustible matter thus leading to significant reduction in waste volume and weight. The main purpose of any medical waste incinerator is to eliminate pathogens from waste and reduce the waste to ashes. However, certain types of medical wastes, such as pharmaceutical or chemical wastes, require higher temperatures for complete destruction.
Medical waste incinerators typically operate at high temperatures between 900 and 1200°C. Developing countries of Asia and Africa usually use low-cost, high-temperature incinerators of simple design for stabilization of healthcare wastes. The most reliable and predominant medical waste incineration technology is pyrolytic incineration, also known as controlled air incineration or double-chamber incineration. The pyrolytic incinerator comprises a pyrolytic chamber and a post-combustion chamber.
Medical waste is thermally decomposed in the pyrolytic chamber through an oxygen-deficient, medium-temperature combustion process (800– 900°C), producing solid ashes and gases. The gases produced in the pyrolytic chamber are burned at high temperature (900– 1200°C) by a fuel burner in the post-combustion chamber, using an excess of air to minimize smoke and odours.
Small-scale decentralized incinerators used in hospitals, of capacity 200–1000kg/day, are operated on demand in developing countries, such as India. On the other hand, off-site regional facilities have large-scale incinerators of capacity 1–8 tonnes/day, operating continuously and equipped with automatic loading and de-ashing devices. In recent years, mobile incinerators are getting attraction in developing world as such units permit on-site waste treatment in hospitals and clinics, thus avoiding the need to transport infectious waste across the city.
However, the WHO policy paper of 2004 and the Stockholm Convention, has stressed the need to consider the risks associated with the incineration of healthcare waste in the form of particulate matter, heavy metals, acid gases, carbon monoxide, organic compounds, pathogens etc. In addition, leachable organic compounds, like dioxins and heavy metals, are usually present in bottom ash residues. Due to these factors, many industrialized countries are phasing out healthcare waste incinerators and exploring technologies that do not produce any dioxins. Countries like United States, Ireland, Portugal, Canada and Germany have completely shut down or put a moratorium on medical waste incinerators.
The first thing that comes to mind when you hear solar power is a solar panel placed on a rooftop for creating electricity for commercial or residential use. However, solar power has another important function – to mine and deliver water to improve productivity. This is especially applicable in sunny nations like Australia and most countries in Africa since its main industry is agriculture. Still, their productivity is suffering since their fields don’t get sufficient irrigation. Though, using solar pumps, they can double or even triple their profits. These economic gains can improve the lives of many farming communities.
Importance of Water in Agriculture
Our lives depend on clean water. The developed countries can sometimes take water for granted, but the evolving economies understand the significance of this commodity. A solar pump is an ecological option to get water for the crops and deliver drinkable, clean water.
The founder and CEO of the British-American company Ignite Power, Yariv Cohen, confirmed that solar pumps brought more efficiency, leading to bigger disposable income and more employment. Farmers can now grow three seasons per year instead of one. So, disposable income increased by 20% to 30%.
60% of the Sub-Saharan Africa population is employed in agriculture. Therefore, agriculture is accountable for 60% of economic output. This is less productive than the other regions in the world since only a part of the farmland gets constant irrigation – just 6% across Africa. Most farmlands go without irrigation, so most farmers in Africa rely only on rain for the larger lands, while they take care of the smaller areas with manual effort.
What is Solar-Powered Pumping System
The solar-powered pumping systems include a solar panel array, which fuels an electric motor. The motor, in turn, fuels the surface pump. The water is pumped from the stream or ground into a storage tank, utilized to water crops. If the farmland is irrigated consistently with solar pumps, the farmers will double the production compared to farmlands irrigated by rainwater or with manual effort.
About 600 million who live in Africa don’t have consistent electricity access. This is damaging the economic health of the continent. Everyone knows the ideal solution is to expand the electrical grid, but financial and geographical considerations prevent that. Ignite Power provides off-grid solutions to African countries in rural places like Nigeria, Mozambique, Rwanda, and Sierra Leone.
Cohen explains how solar pumps allow the farmers to irrigate their lands by using the sun. They first connect the homes, and then they utilize the same solar panels to water the fields. Using solar power, the pump enables a big area to be regularly irrigated. This improves the yield affordably.
Ignite Power has 1.1 million customers in Africa. So, there is room for enormous growth for his company and other providers of solar power in the continent. Cohen aims to reach 500 million houses.
They work with the bank and try to find the ideal solutions. They want to provide the best solution for the country with the help of the government. They can connect any payment providers or manufacturers to their system. They can connect all the suppliers, so many people could join.
The case of the two Rwandan women Grace Uwas (23) and Tharcille Tuyisenge (20) is admirable. They started working with Cohen’s company and bought solar systems for homes in Rwamagana, so people there have sustainable and safe electricity. Until now, they have installed twenty-five solar systems and more are coming!
Electricity is the quintessence for any country. The solar power is game changing for African evolving communities to get access. In this way, they won’t just keep their lights on, but their agricultural productivity will be improved.
Many countries around the world have switched to solar power in order to supplement or provide an alternative source of energy that is cheaper, more reliable and efficient, and friendly to the environment. Generally speaking, to convert solar energy to electricity, there are two kinds of technologies used by the solar power plants – the PV (photovoltaic) systems which use solar panels to convert sunlight directly into electricity, and the CSP (Concentrated Solar Power) that indirectly uses the solar thermal energy to produce electricity.
The solar PV systems, which are either placed in ground-mounted solar farms or on rooftops are considered cheaper than CSP and constitutes the majority of solar installations, while CSP and large-scale PV accounts for the majority of the general solar electricity-generation-capacity, across the globe.
Global Trends in Solar Energy
In 2017, photovoltaic capacity increased by 95 GW, with a 34% growth year-on-year of new installations. Cumulative installed capacity exceeded 401 GW by the end of the year, sufficient to supply 2.1 percent of the world’s total electricity consumption. This growth was dramatic, and scientists viewed it as a crucial way to meet the world’s commitments to climate change.
“In most countries around the world there is still huge potential to dramatically increase the amount of energy we’re able to get from solar. The only way to achieve this is through a combination of both governance and individual responsibility.” Alastair Kay, Editor at Green Business Watch
Both CSP and PV systems are undergoing a considerable amount of growth and experts claim that by 2050, solar power will become the greatest source of electricity in the whole world. To achieve this goal, the capacity of PV systems should grow up to 4600 gigawatts, of which 50% or more would come from India or China. To date, the capacity of solar power is about 310 gigawatts, a drastic increase on the 50 gigawatts of power installed in 2010.
The United Kingdom, followed by Germany and France led Europe in the 2016 general statistics for solar power growth with new solar installations of 29%, 21%, and 8.3% respectively. In early 2016, the amount of power across Europe was near 100 gigawatts but now stands at 105 gigawatts. This growth is regarded as slow and experts in the solar industry are calling upon the European Union to give more targets concerning the renewable source of energy. It is said that setting a target that is not less than 35% will revive the solar business in Europe.
Across the United States in places, such as Phoenix and Los Angeles, which are located in a sunny region, a common PV system can generate an average of 7500 kWh – similar to the electrical power in use in a typical US home.
In Africa, many nations especially those around the deserts such as Sahara receive a great deal of sunlight every day, creating an opportunity for the development of solar technology across the region. Distribution of PV systems is almost uniform in Africa with the majority of countries receiving about 2000 kWh/m2 in every year. A certain study shows that generating solar power in a facility covering about 0.3% of the area consisting of North Africa could provide all the energy needed by the European-Union.
Asia alone contributed to 66.66% of the global amount of solar power installed in 2016, with about 50% coming from China.
With these reports, it is clear that the development of solar energy technology is growing in each and every continent with just a few countries with little or no apparent growth.
The growth of solar power technology across every continent in the world is very fast and steady and in the near future, almost every country will have a history to tell about the numerous benefits of going solar. The adoption of solar power will help improve the development of other sectors of the economy, such as the electronics industry, hence creating a lot of employment opportunities.
Waste disposal methods vary from city to city, state to state and region to region. It equally depends on the kind and type of waste generated. In determining the disposal method that a city or nation should adopt, some factors like type, kind, quantity, frequency, and forms of waste need to be considered.
For the purpose of this article, we will look at the three common waste disposal methods in Africa and the kind of waste they accept.
This is the crudest means of disposing of waste and it is mostly practiced in rural areas, semi-urban settlements, and undeveloped urban areas. For open dumping or open burning, every type and form of waste (including household waste, hazardous wastes, tires, batteries, chemicals) is dumped in an open area within a community or outside different homes in a community and same being set on fire after a number of days or when the waste generator or community feels it should be burnt.
There is no gainsaying that the negative health and environmental impact of such practice are huge only if the propagators know better.
This is apparent in most States in Nigeria, if not all and some cities in Africa like Mozambique, Ghana, Kenya, Cameroon, to mention but a few. It is a method of disposing of all kinds of waste in a designated area of land by waste collectors and it is usually controlled by the State or City Government.
Opening burning of trash is a common practice across Africa
Controlled dumps are commonly found in urban areas and because they are managed by the government, some dumps do have certain features of a landfill like tenure of usage, basic record keeping, waste covering, etc. Many cities in Nigeria confuse the practice of controlled dumping as landfilling but this not so because a landfill involves engineering design, planning, and operation.
A sanitary landfill is arguably the most desired waste management option in reducing or eliminating public health hazards and environmental pollution. The landfill is the final disposal site for all forms and types of waste after the recyclable materials must have been separated for other usages and other biodegradables have been extracted from the waste for use as compost, heat, or energy; or after incineration. These extractions can be done at household level or Material Recovery Facilities (MRFs) operated by the government or private individuals.
As desirable as a landfill is, so many factors need to be put into consideration in its siting and operation plus it requires a huge investment in construction and operation. Some of these factors include but not limited to distance from the residential area, proximity to water bodies, water-table level of the area the landfill is to be sited, earth material availability, and access road.
Nigeria, the most populous country in Africa with population exceeding 182 million people, is grappling with waste management issues. The country generates around 43.2 million tonnes of waste annually. By 2025 with a population of 233.5 million, Nigeria will be generating an estimated 72.46 million tonnes of waste annually at a projected rate of 0.85 kg of waste/capita/day. This means that Nigeria annual waste generation will almost equal its crude oil production which currently stands at approximately 89.63 million tonnes per year.
Also, at an estimated annual waste generation figure of 72.46 million tonnes, Nigeria will be generating about one-fourth of the total waste that will be produced in the whole of Africa. This is scary and if proper attention is not paid to this enormous challenge, Nigeria might become the “Waste Capital of Africa”.
Waste is a Resource for Nigeria
Nonetheless, this challenge can be turned into a blessing because waste is a resource in disguise. If its potential is properly tapped, waste management can create employment, enable power generation, create a waste-based economy and contribute to economic diversification which Nigeria. There is no doubt that this is achievable because we have examples of countries already utilizing their waste judiciously.
Some good examples of sustainable waste management systems that can be implemented in Nigeria includes (1) Shanghai (China) which turn 50% of the waste generated into power generation electrifying 100,000 homes; (2) Incheon (South Korea) where its Sudokwon landfill receives about 20,000 tons of waste daily which is converted into electric power, has a water recycling and desalination facility, and has created more than 200 jobs; (3) Los Angeles (USA) which produces electric power enough for 70,000 homes in its Puente Hills landfill; (4) Germany whose sophisticated waste processing systems through recycling, composting, and energy generation has already saved the country 20% of the cost of metals and 3% of the cost of energy imports; (5) Austria, though a small country, is doing big things in waste management especially through recycling; (6) Sweden, whose recycling is so revolutionary that the country had to import waste; and (7) Flanders, Belgium which possesses the best waste diversion rate in Europe with 75% of their waste being reused, recycled or composted. An interesting fact is that per capita waste generation rate in Flanders is more than twice that of Nigeria at 1.5 kg/day.
Waste Management Outlook for Nigeria
Below are some of the major things the government need to do to judiciously utilize the free and abundant resource available in the form of trash in Nigeria:
Firstly, attention needs to be paid to building the human resource potential of the country to build the required capacity in conceptualizing fit-for-purpose innovative solution to be deployed in tackling and solving the waste challenge.
While knowledge exchange/transfer through international public private partnership is a possible way in providing waste management solution, it is not sustainable for the country especially because there is already an unemployment problem in Nigeria. Hence, funding the training of interested and passionate individuals and entrepreneurs in waste management is a better way of tackling the waste crisis in Nigeria.
Olusosun is the largest dumpsite in Nigeria
The Federal Government through the Petroleum Trust Development Fund (PTDF) and National Information Technology Development Agency (NITDA) of the Ministry of Communication currently sponsor students to study oil and gas as well as information technology related subjects in foreign countries in the hope of boosting manpower in both sectors of the economy. The same approach should be used in the waste management sector and this can be handled through the Federal Ministry of Environment.
Interestingly, waste generation is almost at par with crude oil production in Nigeria. Therefore, equal attention should be paid to waste-to-wealth sector. Needless to say, this is important as there is no university in Nigeria currently offering waste management as a stand-alone course either at undergraduate or postgraduate level.
Secondly, there is an urgent need for a strong National Waste Management Strategy to checkmate the different types of waste that enters the country’s waste stream as well as the quantity of waste being produced. To develop an effective national waste strategy, a study should be carried out to understand the country’s current stream of waste, generation pattern, and existing management approach. This should be championed by the Federal Ministry of Environment in conjunction with State and Local Government waste management authorities.
Once this is done, each State of the Federation will now integrate their own individual State Waste Management Plan into that of the Federal Government to achieve a holistic waste management development in Nigeria. By so doing, the government would also contribute to climate change mitigation because the methane produced when waste degrades is 25 times more potent than carbon dioxide (a major greenhouse gas known to many and contributor to global warming).
Finally, the government needs to support existing waste management initiatives either through tax-holiday on major equipment that need to be imported for their work and/or on their operation for a certain period of time. Also, if workable, the government can float a grant for innovative ideas and provide liberal subsidies in waste management to jumpstart the growth of the sector.
Lastly, the Government of Nigeria can raise a delegation of experts, entrepreneurs, industry professionals, academia, and youngsters to visit countries with sound waste management strategy for knowledge sharing, capacity-building, technology transfer and first-hand experience.
Note: The unedited version of the article can be found at this link
The Palm Oil industry in Southeast Asia and Africa generates large quantity of biomass wastes whose disposal is a challenging task. Palm kernel shells (or PKS) are the shell fractions left after the nut has been removed after crushing in the Palm Oil mill. Kernel shells are a fibrous material and can be easily handled in bulk directly from the product line to the end use. Large and small shell fractions are mixed with dust-like fractions and small fibres. Moisture content in kernel shells is low compared to other biomass residues with different sources suggesting values between 11% and 13%.
Palm kernel shells contain residues of Palm Oil, which accounts for its slightly higher heating value than average lignocellulosic biomass. Compared to other residues from the industry, it is a good quality biomass fuel with uniform size distribution, easy handling, easy crushing, and limited biological activity due to low moisture content. PKS can be readily co-fired with coal in grate fired -and fluidized bed boilers as well as cement kilns in order to diversify the fuel mix.
The primary use of palm kernel shells is as a boiler fuel supplementing the fibre which is used as primary fuel. In recent years kernel shells are sold as alternative fuel around the world. Besides selling shells in bulk, there are companies that produce fuel briquettes from shells which may include partial carbonisation of the material to improve the combustion characteristics. As a raw material for fuel briquettes, palm shells are reported to have the same calorific characteristics as coconut shells. The relatively smaller size makes it easier to carbonise for mass production, and its resulting palm shell charcoal can be pressed into a heat efficient biomass briquette.
Palm kernel shells have been traditionally used as solid fuels for steam boilers in palm oil mills across Southeast Asia. The steam generated is used to run turbines for electricity production. These two solid fuels alone are able to generate more than enough energy to meet the energy demands of a palm oil mill. Most palm oil mills in the region are self-sufficient in terms of energy by making use of kernel shells and mesocarp fibers in cogeneration. In recent years, the demand for palm kernel shells has increased considerably in Europe, Asia-Pacific, China etc resulting in price close to that of coal. Nowadays, cement industries and power producers are increasingly using palm kernel shells to replace coal. In grate-fired boiler systems, fluidized-bed boiler systems and cement kilns, palm kernel shells are an excellent fuel.
Cofiring of PKS yields added value for power plants and cement kilns, because the fuel significantly reduces carbon emissions – this added value can be expressed in the form of renewable energy certificates, carbon credits, etc. However, there is a great scope for introduction of high-efficiency cogeneration systems in the industry which will result in substantial supply of excess power to the public grid and supply of surplus PKS to other nations. Palm kernel shell is already extensively in demand domestically by local industries for meeting process heating requirements, thus creating supply shortages in the market.
Palm oil mills around the world may seize an opportunity to supply electricity for its surrounding plantation areas using palm kernel shells, empty fruit branches and palm oil mill effluent which have not been fully exploited yet. This new business will be beneficial for all parties, increase the profitability for palm oil industry, reduce greenhouse gas emissions and increase the electrification ratio in surrounding plantation regions.
Feeding a growing world population could become problematic, but aquaculture might hold the key. If humans are anything, we are resourceful. We see a problem with the world, and we do what we can to fix it. When being nomadic and following food sources was no longer sustainable, we solved the problem by developing agriculture. Currently, as the population continues to grow and our taste for seafood increases, we’re trying to find ways to meet demand and, at the same time, sustain wild populations of fishes.
Aquaculture is the answer to this current dilemma. Farming fish for food has been around since about 2000 B.C. Since then, technology has helped it advanced and developed better techniques to raise fish for food.
The health benefits of fish are more than enough reason to eat them, but they are also a delicious meal. There is a large variety of fish to choose from, including freshwater and saltwater varieties. However, the increased amount of people eating fish has had an impact on wild populations. To prevent certain species from being overfished, it is important to find an alternative to providing fish to people, and that includes aquaculture.
Different types of aquaculture must be used to raise different species of fish. Large companies can engage in aquaculture on an industrial scale with fish held in tanks or in pens in lakes, ponds or even the ocean. Families can even perform aquaculture in their backyard. The variety of fish that you can raise for food includes catfish, bait minnow, trout, carp and tilapia, among others. It’s also possible to raise shellfish, including oysters and shrimp. Want to try your hand at growing water plants? You can also use aquaculture principles for water chestnuts and red and brown algae.
While it has the potential to feed hungry communities and contribute to local economies, there are some problems associated with aquaculture. Having too many fish in a tank can lead to the spread of disease. Also, the type of feed the fish eat can impact how healthy they are for humans. Keeping fish in pens in lakes, ponds or the ocean might cause the spread of parasites to wild populations. Farmed fish could also escape their enclosure and, as a result, alter the natural ecosystem.
Recognizing the shortcomings of aquaculture is the first step to remedying its problems. As technology and farming practices advance and techniques improve, it’s possible that we will resolve many of these issues. This will lead to greater benefits for the human population that depends on fish for food.
Humans have the ingenuity and drive to make the world a better place for themselves and others. Population growth isn’t going to slow down any time soon, and we need to make sure everyone is taken care of and has enough to eat. While aquaculture has its pros and cons, it can be a sustainable and economic way to feed hungry people. In time, it may even be the answer to world hunger.
Solid waste management is the most pressing environmental challenge faced by urban and rural areas of Nigeria. Nigeria, with population exceeding 170 million, is one of the largest producers of solid waste in Africa. Despite a host of policies and regulations, solid waste management in the country is assuming alarming proportions with each passing day.
Nigeria generates more than 32 million tons of solid waste annually, out of which only 20-30% is collected. Reckless disposal of MSW has led to blockage of sewers and drainage networks, and choking of water bodies. Most of the wastes is generated by households and in some cases, by local industries, artisans and traders which litters the immediate surroundings. Improper collection and disposal of municipal wastes is leading to an environmental catastrophe as the country currently lack adequate budgetary provisions for the implementation of integrated waste management programmes across the States.
According to the United Nations Habitat Watch, African city populations will more than triple over the next 40 years. African cities are already inundated with slums; a phenomenon that could triple urban populations and spell disaster, unless urgent actions are initiated. Out of the 36 states and a federal capital in the country, only a few have shown a considerable level of resolve to take proactive steps in fighting this scourge, while the rest have merely paid lip services to issues of waste management indicating a huge lack of interest to develop the waste sector.
Scenario in Lagos
Lagos State, the commercial hub of Nigeria, is the second fastest growing city in Africa and seventh in the world. The latest reports estimate its population to be more than 21 million making it the largest city in entire Africa. With per capita waste generation of 0.5 kg per day, the city generates more than 10,000 tons of urban waste every day.
Despite being a model for other states in the country, municipal waste management is a big challenge for the Lagos State Waste Management Agency (LAWMA) to manage alone, hence the need to engage the services of private waste firms and other franchisee to reduce the burden of waste collection and disposal. One fundamental issue is the delayed collection of household solid waste. In some cases, the wastes are not collected until after a week or two, consequently, the waste bin overflows and litters the surroundings.
Improper waste disposal and lack of reliable transport infrastructure means that collected wastes are soon dispersed to other localities. Another unwelcome practice is to overload collection trucks with 5-6 tons of waste to reduce the number of trips; this has necessitated calls by environmental activist to prevail on the relevant legislature to conform to the modern waste transportation standard.
Situation in Oyo
Away from Lagos State, Oyo is another ancient town in Nigeria with an estimated population of six million people. Here, solid waste is regulated by the Oyo State Solid Waste Management Authority (OYOWMA). Unlike Lagos State, Oyo State does not have a proper waste management scheme that cuts across the nooks and crannies of the state, apart from Ibadan, the capital city, people from other towns like Ogbomoso and Iseyin resort to waste burning. In case the waste generators feels that the amount being charged by the waste franchisee is beyond their means, they dump the waste along flood paths thus compounding the waste predicament.
Burning of municipal wastes is a common practice in Nigeria
Kano and Rivers State with its fair share of population also suffers similar fate in controlling and managing solid waste. Generally speaking, population increase in Nigeria has led to an unprecedented growth in its economy but with a devastating effect on the environment as more wastes are generated due to the need for housing, manufacturing industries and a boost in trade volume.
The government at the federal level as a matter of urgency needs to revive its regulatory framework that will be attractive for private sectors to invest in waste collection, recycling and reusing. The environmental health officer’s registration council of Nigeria would do well to intensify more effort to monitor and enforce sanitation laws as well as regulate the activities of the franchisees on good sustainable practices.
Taking the advocacy further on waste management, to avoid littering the environment, some manufacturing companies (e.g. chemical and paint industry) have introduced a recall process that will reward individuals who returns empty/used plastic containers. This cash incentive has been proven over time to validate the waste to wealth program embarked upon by the manufacturing companies. It is also expected that the government will build more composting and recycling plants in addition to the ones in Ekiti and Kano State to ensure good sustainable waste management.
Waste management situation in Nigeria currently requires concerted effort to sensitize the general public on the need for proper disposal of solid waste. Also, the officials should be well trained on professionalism, service delivery and ensure that other states within the country have access to quality waste managers who are within reach and can assist on the best approach to managing their waste before collection.
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