Bioconversion of Rice Husk Plus Wood Waste into Organic Fertilizer Using Sugarcane Molasses and Corn Steep Liquor

Document Type : Research Article

Authors

1 Faculty of Chemistry and Chemical Engineering, Malek Ashtar University of Technology

2 Faculty of chemistry and chemical Eng., Malek-Ashtar University of Technology, Tehran, Iran

3 Faculty of Chemistry and Chemical Engineering, Malek

Abstract

Rice husk is one of the critical agricultural by-products in the rice milling process; it is abundantly produced and often left unused or burned in the environment. In this study, the biotransformation potential of this material into biological organic fertilizer was investigated using a mixture of wood lignocellulolytic microorganisms and natural rice husk compost. Corn steep liquor with 50 ± 5% solid materials in a total ratio of 15% (w/w) and sugar cane molasses (SCM) with 60 ± 5% solids in a total ratio of 15% (w/w) to the treated solids materials were used to supply microorganism's nutrients and optimization of biochemical, organic fertilizer elements. A rice husk sample and two other rice husks, combined with wood waste, were treated in a mixture of the mentioned additives and microorganisms. Samples at certain intervals were determined to have the amount of nitrogen, organic matter, organic carbon, essential elements, and the C/N ratio as the main parameters to evaluate the quality and maturity of biofertilizer in the conversion period. Based on the results, the biological conversion process converted rice husk into organic biofertilizer. Also, using wood waste along with rice husk, at first, caused a relative decrease in minerals and an increase in the C/N ratio, but this effect decreased with the progress of the process. In addition, during the biotransformation process, with the relative decrease of organic matter and organic carbon, the relative amounts of K+, PO_4^(3-), Ca2+ and Mg2+ increased significantly and reached acceptable levels. A rice husk and wood waste mixture can be converted into superior-quality organic fertilizer using low-cost CSL, starch, or sugarcane molasses.

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