My idea in a nutshell: Agricultural wastes such as banana peel, peanut shells, spent coffee grounds, and rice straw / rice hull will be used to produce activated carbon, which I will name as PestiSorb. It will be used mainly to clean pesticide rinsate prior to disposal. The treated pesticide rinsate is expected to be safer to aquatic organisms. PestiSorb could also be utilized as a mulching agent to prevent the growth of weeds, and could also be soil incorporated to serve as a layer of barrier to reduce risks of pesticide leaching or agricultural runoff to ground water or surface water.
The Challenge: Benefit-Risk Dilemma of Pesticide Use
The use of pesticides to protect crops from pests and diseases to attain food security is an essential part of the integrated pest management. It is always accompanied by both benefits and risks and is generally considered acceptable if judicious use is followed. In field applications of pesticides, the pesticide rinsate (simply the dilute pesticide solution resulting from the cleaning of pesticide application equipment) could pose environmental risks if not properly treated or disposed. It could affect aquatic organisms, ground water, and surface water, depending on different physico-chemical, soil, and climatic factors.
The Utilization of Agricultural Wastes: Hitting Two Birds in One Stone
Agricultural wastes from different sectors such as households (banana peel, peanut shells), local industries (used coffee grounds, used tea leaves), and farming sector (rice hull, rice husk) are all carbon-based and offers the potential to be used as starting materials to produce activated carbon, which I will name as PestiSorb. PestiSorb will be used as an adsorbent to treat pesticide rinsate, making it safer for the environment upon disposal. This is similar to hitting two birds in one stone: the reduction of agricultural wastes in different sectors and the cleaning of pesticide rinsate prior to disposal.
The potential uses of PestiSorb: added value beyond remediation of pesticide rinsate
PestiSorb could also be used as a mulch (a layer of material applied to the surface of the soil) to reduce the growth of weeds in the farms. It could also lessen the pesticide that will go to the soil upon pesticide application, hence protecting macro and microorganisms in the soil. PestiSorb could also be incorporated in the soil (at certain depths) in borders between farms and bodies of water, serving as a barrier to minimize the risks of contaminating the aquatic environment through agricultural runoff/seepage. It could also be packed in sacks and be used to treat small bodies of water such as streams because it could also probably adsorbed other contaminants such as heavy metals, organic matter, etc. Laslty, PestiSorb could possibly enhance soil structure and nutrition by providing additional carbon source to beneficial soil macro and microorganisms.
Implementation: the key for making the idea a reality
To turn my idea into reality, agricultural wastes will be collected. For each waste, drying and homogenization to small particles will be done, followed by converting to activated carbon through high temperature treatment. Dilute pesticide solutions will be prepared and the processed wastes will be reacted to the pesticide, followed by filtration. To determine the effect of the treatment, the pesticide level in the original pesticide and in the PestiSorb-treated pesticide will be compared using the method Rapid Bioassay for Pesticide Residues (RBPR). The original and the clean pesticide will be used to grow an aquatic plant (e.g. Lemna sp.) to determine the reduction in toxicity.
Being an agricultural chemist by profession and an MS Environmental Science student, my main motivation is on how I can use chemistry to solve an environmental problem related to agriculture in a way that is sustainable. Being agricultural waste management as one of the main challenges in an agricultural country like the Philippines, I was inspired to think of a possible way of utilizing the wastes as a source of a possible solution to the problem that I wish to solve. Hence, the birth of this idea.
The multi-sectoral beneficiaries
If I will be given a chance to be one of the N-GAGE champions, I will use the seed funding to develop PestiSorb and make an impact to the different sectors in terms of reducing their agricultural wastes and reducing the risks to the environment. With my idea, I am hoping to establish partnerships with local coffee shops being the source of used coffee grounds, households being the source of banana peel, and farmers being the source of rice straw or rice husk. Once PestiSorb is developed, it will be distributed to farmers for use as they are the ultimate beneficiaries of this innovation.
I have done a preliminary evaluation of the potential of used coffee grounds (not yet converted to activated carbon) to remove the pesticide profenofos in water. I analyzed both the original and cleaned pesticide solution using a method called Rapid Bioassay for Pesticide Residues (RBPR), which is basically an enzymatic method to determine inhibitory effect of pesticides to the enzyme acetylcholinesterase. The higher the inhibition, the higher is the amount and the toxicity of the pesticide. Initial data showed a reduction in the inhibition of the enzyme in the pesticide treated with used coffee grounds, implying a lower amount and toxicity of the pesticide, hence cleaner and safer to dispose.
Eric Jhon D. Cruz, Philippines