N Raghuram, president of ING (Indian Nitrogen group) states that sewage and solid waste are the second largest source of nitrogen pollution and if it is recycled then fertilizer usage can be curbed by 40 %. The modified biochar can be used as a medium to recycle these nutrients. The biochar can single-handedly addresses the various problem and provide a sustainable solution. Following are the issues addressed in the project: • Waste management of crop residual • Tertiary treatment of water using biochar • Form the loop of nutrient recycling by clipping off the stage of disposal of nutrients in water bodies • Increase the irrigation and fertilizer use efficiency by field application • Reserve the carbon into the soil (Carbon sequestration)
India produces 600 million tons of surplus agricultural biomass that can be transformed into a product of economic importance. CII - NITI Aayog ’s (2018) reports that in UP, Punjab, Rajasthan, and Haryana nearly 39 million tonnes of paddy straw is burnt annually. Punjab alone produces 19.7 mt of paddy straw annually and burn 15.4 mt because of its less utility due to high silica content and low calorific value compared to other biomass. Preparation and use of biochar from these agricultural residues can serve as a solution to multiple problems like CO2, aerosols, other gaseous emissions, agricultural residue and soil biota damage due to biomass burning. This biochar can be utilized as a medium for tertiary wastewater treatment and remove nutrients from it. Later on, the loaded biochar used as a fertilizer for the plants. As the biochar has larger BET surface area, it adsorbs nutrients to its surface and also holds water molecules tightly which help in increasing the fertilizer use efficiency as well as irrigation efficiency. However, due to negative surface charge, it has some constraints in adsorbing more nutrients to its surface. The study aims to increase the nutrient uptake capacity of biochar by introducing some modifications to it keeping in mind that modifications are suitable for the soil. The modification of biochar is a valuable addition to the surface of biochar as it strengthens the key parameters of adsorption, i.e., surface area, Point of zero charge (pHpzc) and functional groups. The most common nutrients found in the secondary treated wastewater like Phosphate, Nitrate, and ammonium that lead to a common problem of algal bloom in water bodies can be transferred from liquid to a solid medium (Biochar) and can be easily transported to agricultural fields. Application of such biochar to the field will act as slow-release fertilizer for the plants as they hold nutrients tightly and also increase the nutrient use efficiency by preventing the leaching of nutrients away from the root zone of plants. Biochar itself adds carbon content to the soil and is arduous to degrade due to an increase in recalcitrance during pyrolysis.
Link: • Recycle highly potent agricultural waste to a useful product.
• When the nutrients are depleted from the soil after some time, the inorganic nutrients can be applied to the field treated with biochar such that biochar can hold those nutrients, prevent it from leaching and slowly release them in the root zone of plants.
• Modification of biochar with inexpensive, soil friendly and accessible ingredients to improve the soil health.
Problem Scale: Worldwide
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