Conversion of rice straw (RS) as one of agricultural plant wastes (about 45% of the volume of rice production) to valuable industrial product was achieved, by grafting different amounts of dimethylaminoethyl methacryl...Conversion of rice straw (RS) as one of agricultural plant wastes (about 45% of the volume of rice production) to valuable industrial product was achieved, by grafting different amounts of dimethylaminoethyl methacrylate (DMAEM) on it using potassium permanganate/nitric acid redox system. This was done to obtain six levels of poly (DMAEM)—rice straw graft copolymers (PDMAEMRS) having different graft yields (expressed as N%) with increasing order and designated as (PDMAEMRS 1 to PDMAEMRS 6). The latter copolymers were dispersed in aqueous solution of heavy metal ions Cu (II) ions and filtered to form rice straw co-polymer—metal ions complex. Different factors affecting the heavy metal ions removal such as pH, extent of grafting, treatment time and rice straw dose were studied in detail. It was found from the obtained results that;the residual metal ions removal from their aqueous solutions increased with 1) increasing the extent of grafting of PDMAEMRS i.e. from PDMAEMRS 1 to PDMAEMRS 6;2) increasing the pH of the metal ions solution complex from 1 to 8;3) increasing the rice straw dosage from 0.50 to 2.0 g, then leveled off thereafter;4) increasing the time of the reaction up to 20 minute then leveled off after that. On the other hand, Pb (II), Cd (II) and Hg (II) ions were also removed from their solutions with different extent. Furthermore, the prepared co-polymer could be recovered by washing the metal ions from the complex with weak acid 1 N HNO3 (pH 2) and the metal-binding activity of the rice straw was slightly reduced by this process. Finally, the ability of PDMAEMRS to remove three types of acid dyes from their solutions was also reported.展开更多
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 b...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.展开更多
文摘Conversion of rice straw (RS) as one of agricultural plant wastes (about 45% of the volume of rice production) to valuable industrial product was achieved, by grafting different amounts of dimethylaminoethyl methacrylate (DMAEM) on it using potassium permanganate/nitric acid redox system. This was done to obtain six levels of poly (DMAEM)—rice straw graft copolymers (PDMAEMRS) having different graft yields (expressed as N%) with increasing order and designated as (PDMAEMRS 1 to PDMAEMRS 6). The latter copolymers were dispersed in aqueous solution of heavy metal ions Cu (II) ions and filtered to form rice straw co-polymer—metal ions complex. Different factors affecting the heavy metal ions removal such as pH, extent of grafting, treatment time and rice straw dose were studied in detail. It was found from the obtained results that;the residual metal ions removal from their aqueous solutions increased with 1) increasing the extent of grafting of PDMAEMRS i.e. from PDMAEMRS 1 to PDMAEMRS 6;2) increasing the pH of the metal ions solution complex from 1 to 8;3) increasing the rice straw dosage from 0.50 to 2.0 g, then leveled off thereafter;4) increasing the time of the reaction up to 20 minute then leveled off after that. On the other hand, Pb (II), Cd (II) and Hg (II) ions were also removed from their solutions with different extent. Furthermore, the prepared co-polymer could be recovered by washing the metal ions from the complex with weak acid 1 N HNO3 (pH 2) and the metal-binding activity of the rice straw was slightly reduced by this process. Finally, the ability of PDMAEMRS to remove three types of acid dyes from their solutions was also reported.
文摘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.
