Assessment of the nutrient recovery process from chicken droppings digestate with jackfruit waste-based biochar as an adsorbent.

Abstract

Responsible consumption and production is one of the key tools towards sustainable development and this can be achieved through reducing waste generation, prevention, recycling and reuse of waste. Jackfruit is one of the commonly grown fruits in Uganda as it can withstand almost all climatic conditions in the country. Due to the fact that only around 33% of the fruit is edible, there is a huge amount generated as waste due to consumption of jackfruit. This study explored the process efficiency of the use of jackfruit waste-based biochar as an adsorbent of nutrients particularly NPK (Nitrogen, Phosphorus, Potassium) from chicken droppings digestate. Adsorbed NPK nutrients can be used to make pure fertilizers that can be tailor according the specific nutrient requirement of a plant. All steps of biochar production from jackfruit waste collection to pyrolysis were included in the study. The experimental preparations involve mixing of biochar with chicken droppings digestate and then subjecting the mixture to different parameters such as temperature, concentration and the contact time. The adsorption isotherm models of jackfruit waste biochar were obtained from the nutrient concentration results for each parameter. . Thermo gravimetric analysis (TGA) and Differential thermal analysis (DTG) plots were obtained during the study and these tell the combustion behavior of the waste as the temperatures are increased. The efficiency of the adsorption process according to the study depends on the nature of adsorption of nutrients. The study showed that jackfruit waste based-biochar has got good sorption properties thus an ideal tool of NPK nutrient recovery or use pure fertilizer production.