Rice straw management through biofuel, biochar, mushroom cultivation, and paper production to overcome environmental pollution in North India

Rice is the prominent food grain required by more than half of the world's population to fulfill their nutritional demand. With the continuous growth in the population at the global level, rice production has also been elevated. However, high rice production also creates a new problem in waste management worldwide. Rice straw, generated after rice harvest, possesses meager nutritional value, due to which it is less preferred as fodder and burned in the field. Paddy burning is one of the major causes of air pollution, leading to lung, heart, eye, and skin-related diseases and even premature death. This stubble burning also decreases soil fertility. In this review article, we have discussed the various economic uses of paddy straw which will help to reduce air pollution through the decline in paddy straw burning. Biochar is produced from paddy straw, which can be mixed into the soil to restore fertility and reduce toxic metals' bioavailability. The generation of biofuels such as biobutanol, bioethanol, and biogas from rice straw with their mechanism of synthesis is also discussed in this article. Rice straw can also be utilized in the preparation of solid fuel. Along with this, mushroom cultivation in paddy straw houses is also described. Paddy straw can be used for the pulp and paper industries, which will help to reduce the tree dependence of these industries. Apart from this, a bibliometric analysis of the Scopus database on rice straw uses for the last 20 years was done, including a bibliographic keyword analysis to show published documents' trends. This review will give an elaborated overview of the alternative uses of rice straw with a quantitative analysis of air pollution caused by paddy straw burning. This review will also help to improve the current uses of paddy straw for industrial and commercial benefits to make it more economical.

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