Biochar is the solid material which is obtained from the carbonization of biomass. The carbonization of biomass was done through several thermochemical processes such as pyrolysis, hydrothermal carbonization and torrefaction. The main element of biochar is carbon (C). However, it also contains hydrogen (H), oxygen (O) ash and trace elements of (N) and sulfur (S). The elemental composition of biochar varies according to the types of biomass and the carbonization process used. Biochar is commonly produced from various types of biomass such as agricultural residue, wood waste, sludge and the excrement of animals. As an environmental-friendly and inexpensive materials, various studies have been conducted using biochar as an additive for energy production, soil remediation, waste management and greenhouse gas reduction. Due to its porous structure and large specific surface area, biochar has been used mainly as an absorbent for the removal water pollutants and as a soil amendments by reducing the mobility of either nutrients or inorganic and organic contaminants in the soil.

Malaysia produces approximately 1.2 million tone of poultry meat annually. Majority of the poultry farms are of small and medium-scale operating with traditional facilities with minimal waste management. One of the major wastes produce in poultry industry is manure. Poultry manure can be applied directly to soil as an amendment. However, direct application may cause the spread of pathogen and leach of phytotoxic substances and release of excessive nutrients and unpleasant odor. In order to avoid these problems, it has been recommended that the chicken manure should be composted prior to its application as fertilizer. Composting is a self-heating, aerobic decomposition of organic material into stable substances. However, the conditions of composting process could affect the quality of its end products especially the nitrogen content. Nitrogen is one of the most important elements for plant growth. Previous studies showed a significant loss of nitrogen was found during the composting process. The loss of nitrogen occurs through the N mineralization, ammonia (NH₃) volatilization, nitrification, and denitrification. Previous study indicated that composting of chicken litter reduces its values as N fertilizer due to volatilization of ammonium as temperature pile were high. On the other hand, the nitrogen could also be lost as leachates during the composting. Currently, biochar has been used to minimize nitrogen losses during the composting of animal manure. The ammonium emission and the loss of nitrogen can be reduced as low as 60% by using biochar. Apart from nitrogen, the mineral elements found in biochar can also increase the mineral content of the compost. The porous structure and large surface area of biochar makes this material capable of absorbing and hold all of the nutrients and minerals, thus improving the quality of the product.

Date of Input: 28/10/2020 | Updated: 16/06/2021 | mohdhusni