• Agricultural Waste
• Forestry Waste
• Polymer Waste
Agriculture has flourished in areas and regions with favorable conditions for plant growth. Environmental factors such as soil, water, climate, and pollution control are still important in determining where agricultural production and related economic activity take place. The efficiency of agricultural production has increased significantly in recent years. The size of farms and productivity per farm worker have grown. With less land used for production, crop and livestock production per acre, as well as total crop production, are on the rise. Due to the scarcity of labor and the need for them, they were replaced by machines with growing technology. The use of machines has led to technical advances in crop production, harvesting, animal housing, feed handling and waste management.
The productivity of agriculture in recent decades has been remarkable. On-farm workers and non-farm support personnel are among those who contribute to agriculture production. An increase in total farm inputs, machinery, fertilizers, and pesticides has been observed in recent decades, accompanied by a decrease in farm labor. Farm outputs increased at the same time. The annual agricultural productivity increased due to better machines helping in improving the farm's modern management practices and productivity mechanization (Loehr, 1974).
Billions of tons of agricultural waste are generated each year in developing and developed countries. Agricultural residue includes all leaves, straws and husks left in the field after harvest, hulls and shells removed during the processing of crops at the mills. As the developing world population continues to rise, these types of agricultural waste also continue to rise (Yevich & Logan, 2003).
Fig. 1 Increased use of machines for agricultural production (S., 2014)
Problems Due to Agricultural Waste
Agricultural wastes have an effect on the environment because they continue to pollute the planet. Many farmers choose to dispose of the waste by burning them in open fields. Agricultural biomass burning has a big impact on global atmospheric chemistry because it generates a lot of carbon monoxide, nitrogen oxides, and hydrocarbons, especially in the tropics. These gases influence the chemistry of the OH because they are precursors of tropospheric ozone. The incineration of wood, charcoal, and agricultural waste as
household fuel, and the combustion of crop residue in open fields, are two notable aspects of biomass burning (Yevich & Logan, 2003). Some of the agricultural wastes are sent to landfills or left on the ground to decompose. Human health is also threatened by the rising production of agricultural biomass waste. Uncontrolled land disposal pollutes surface and ground waters, causing eutrophication, and when biomass-induced microflora is incorporated into the soil, it stimulates the production and emission of greenhouse gases NO and N2O, which have a much higher global warming potential than CO2. (Tripathi & Hills, 2019).
Another sector is forestry, where the value of planted forests for human communities is becoming increasingly evident as the population grows year after year. To meet the ever-increasing demand for wood, fiber, energy, civil construction, resin, latex, and other materials, new forests have been established (Campinhos, 1999). Under a plan to protect the environment, industries and elite companies are planting more trees than they use. The main reason for these industries' planting trees is rising consumerism and expanding consumer base, as well as the need to maintain a proper balance in the environment and the sharp increase in demand for natural resources (Kröger, 2014).
Fig. 4 Forestry waste (Patterson, 2019)
Problems Due to Forestry Waste
Lumbering wastes consist of grained saw timber, branches of treetops, and off-cuts of timber which appear during sawing of tree trunks. A great part of the forestry wastes is used for the production of biofuel. However, the wider utilization of lumbering wastes is hindered by the large costs of their processing and transportation. For this reason, a substantial part of lumbering wastes remains in forests (Treinyte, Bridziuviene, Fataraite-Urboniene, Rainosalo, Rajan, Cesoniene and Grazuleviciene, 2018).
Uses for Agricultural and Forestry Waste
According to the website 4 Uses for Agricultural Waste, 2020, some types of farm waste that can be recycled for practical purposes include:
• Biofuel - The wood debris (twigs, branches, etc. lying on the ground) that rural populations collect for household fuel use makes up a significant portion of the fuelwood supply in the developing world (Yevich & Logan, 2003). Plant waste can produce biofuels such as biodiesel or ethanol. If crops are rich in cellulose (as corn stalks are) they can be used to make ethanol, a substitute for gasoline. If crops are rich in lipids (such as unproductive oil seeds) they can be used to make biodiesel, a substitute for diesel. Vehicles are increasingly designed to operate on biofuels developed from plants (4 Uses for Agricultural Waste That Can Save Farmers Money, 2020).
• Plastic substitutes - After the juice has been extracted from sugarcane, the stalk that is left is known as bagasse. Bagasse can be used to create plastics such as bowls, plates and other plastic containers. Unlike plastic made from crude oil, plastics made from bagasse are natural fiber products that are compostable and degrade in 30-60 days after use. This makes them a great alternative to Styrofoam and other plastic products (4 Uses for Agricultural Waste That Can Save Farmers Money, 2020).
• Bioplastics - Bioplastics are getting both stronger and greener. These plastics, not designed to break down, are developed from corn and sugarcane. They reduce the company’s overall footprint because they are more sustainably produced than conventional petroleum-based plastics, and are also recyclable. Look for these materials in things like Legos, refrigerators and some packaging. (4 Uses for Agricultural Waste That Can Save Farmers Money, 2020).
• Compost - Animal waste has long been used as a field fertilizer to add nutrients to existing topsoil. However, many people are using manure to mix with other plant byproducts such as straw, corn stover, wood residue or leaves to create a richer compost to be used in gardens and fields. The composting cycle takes around 4-8 months and reduces the volume of the waste by around 30%. Spreading compost (instead of straight manure) on hayfields and pastures can reduce water pollution and allow animals to more efficiently graze after it is spread (4 Uses for Agricultural Waste That Can Save Farmers Money, 2020).
The use of plastic has increased, as it is used in almost all industries. They are often replaced by traditional resources like wood, metal and glass. It’s seen that polymer because of its useful properties is a global trend in many countries. Production is increasing by 9.9% every year. Due to the increase in the production of polymers like polyethene terephthalate (PET), polypropylene (PP), polystyrene (PS) and polyvinyl chloride (PVC), the pollution in seas and the environment has increased. Landfilling is a common method of dumping polymer. Due to legislative pressures (waste to landfill must be reduced by 35 percent between 1995 and 2020), rising costs, and the poor biodegradability of commonly used polymers, landfill disposal is becoming less desirable. Without a doubt, the landfill is the worst option, with the greatest environmental impact. (Datta & Kopczyńska, 2016).
Fig. 5 Polymer waste such as Styrofoam cups and plastic bags (polymer waste, 2021)
Solution for Polymer Waste
Polymers are very difficult to degrade and take hundreds of years to break down into smaller parts and decompose. Climate change is one of the most serious issues, and people are advised to look for alternatives to polymer products. Because existing plastics cannot. be burned or disposed of on land because they may take years to decompose, experts say we must reuse or recycle them to create new products that we can use in our daily lives.
• Reduce and Reuse - Refusing to use and buy plastic products is the most effective way to reduce polymer waste. The most effective ways to conserve natural resources, protect the environment, and save money are to reduce and reuse. For glass containers or drink bottles, reuse is the most common waste management method because they can be cleaned and reused again. Plastic material reuse can be thought of as a zero-order recycling technique. It is preferable to reuse plastics because it consumes less energy and resources. (Datta & Kopczyńska, 2016).
• Recycling - Recycling has seemed to be the most viable option. Waste polymer recycling can be done in a variety of ways. Collection, separation, processing/manufacturing, and marketing are the four stages of polymer material recycling. Because only clean, homogeneous polymer can produce the highest quality recycled plastic products, effective separation of mixed plastic waste is required. Mechanical recycling, chemical or feedstock recycling, and energy recovery are all options for plastic recycling. Plastic solid waste is separated, melted, extruded, and granulated for use in new products in mechanical recycling. Polymers are broken down into monomers or converted to oil or gas for use in other processes in feedstock recycling. Plastic waste is used to generate heat or energy in the energy recovery process. The remaining material waste is either recycled or landfilled after a number of recycling processes (Datta & Kopczyńska, 2016).