Development of an organic fertilizer bioreactor for the bioconversion of dried chicken manure into organic liquid solution

Abstract

Animal manure is an excellent source of nutrients that could support plant nutrients. The result showed that the optimum hydraulic retention period for bioprocessing of dried chicken manure using an organic fertilizer bioreactor is between 7 and 14 days. Within the optimal hydraulic retention periods, the organic fertilizer bioreactor was able to maintain the optimal operating parameters for bioconversion of dried chicken manure to organic liquid fertilizer such as dissolved oxygen (6.67 – 6.73 mg/L), pH (8.83 – 8.88), electrical conductivity (2,061 – 2,096 μS/cm) and total dissolved solids (937 – 947 ppm). In terms of nutrient content, the organic liquid fertilizer produced at optimal hydraulic retention period contained total nitrogen of 233 – 267 ppm, nitrate of 99 – 129 ppm, total phosphorus of 100 – 200 ppm, and total potassium of 400 - 467 ppm. The presence of nitrate suggested that the organic fertilizer bioreactor was able to convert inorganic forms of nitrogen present in the dried chicken manure. The seed germination bioassay suggested that the organic liquid fertilizer produced at optimal hydraulic retention period using an organic fertilizer bioreactor did not inhibit the germination of the cucumber seeds compared to dried chicken manure. The result provided a new methodology for processing dried chicken manure to produce organic liquid fertilizer that could be used as a plant nutrient source alternative to commercial fertilizers.