Excessive waste production has led to the concept of a circular bioeconomy to deliver valuable by-products and improve environmental sustainability.The annual worldwide rice production accounts for more than 750 milli...Excessive waste production has led to the concept of a circular bioeconomy to deliver valuable by-products and improve environmental sustainability.The annual worldwide rice production accounts for more than 750 million tons of grain and 150 million tons of husk.Rice husk(RH)contains valuable biomaterials with extensive applications in various fields.The proportions of each component depend primarily on rice genotype,soil chemistry,and climatic conditions.RH and its derivatives,including ash,biochar,hydrochar,and activated carbon have been placed foreground of applications in agriculture and other industries.While the investigation on RH’s compositions,microstructures,and by-products has been done copiously,owing to its unique features,it is still an open-ended area with enormous scope for innovation,research,and technology.Here,we reviewed the latest applications of RH and its derivatives,including fuel and other energy resources,construction materials,pharmacy,medicine,and nanobiotechnology to keep this versatile biomaterial in the spotlight.展开更多
This paper critically reviewed the current knowledge and challenges of rice husk biochar(RHB)production and its effects on soil properties,plant growth,immobilization of heavy metals,reduction of nutrient leaching and...This paper critically reviewed the current knowledge and challenges of rice husk biochar(RHB)production and its effects on soil properties,plant growth,immobilization of heavy metals,reduction of nutrient leaching and mitigation of greenhouse gas emissions.The characteristics of RHBs produced at various pyrolysis temperatures were discussed and compared to biochars derived from other agro-industrial wastes.RHBs produced at higher pyrolysis temperatures show lower hydrogen/carbon ratio,which suggests the presence of higher aromatic carbon compounds.The increase of pyrolysis temperature also results in production of RHBs with higher ash content,lower yield and higher surface area.RHB usually has higher silicon and ash contents and lower carbon content compared to biochars derived from other feedstocks at the same pyrolysis conditions.Although it depends on soil type,RHB application can improve soil organic carbon content,cation exchange capacity,available K concentration,bulk density and microbial activity.The effect of RHB on soil aggregation mainly depends on soil texture.The growth of different crops is also enhanced by application of RHB.RHB addition to soil can immobilize heavy metals and herbicides and reduce their bioavailability.RHB application shows a significant capacity in reduction of nitrate leaching,although its magnitude depends on the biochar application rate and soil biogeochemical characteristics.Use of RHB,especially in paddy fields,shows a promising mitigation effect on greenhouse gas(CH4,CO2 and N2O)emissions.Although RHB characteristics are also related to other factors such as pyrolysis heating rate and residence time,its performance for specific applications(e.g.carbon sequestration,pH amendment)can be manipulated by adjusting the pyrolysis temperature.More research is needed on long-term field applications of RHB to fully understand the advantages and disadvantages of RHB as a soil amendment.展开更多
Incorporating small amounts of biochar into cementitious materials has partial effects on the environment.In this present study,rice husk was collected as agricultural biomass from a local area of Roorkee Uttarakhand,...Incorporating small amounts of biochar into cementitious materials has partial effects on the environment.In this present study,rice husk was collected as agricultural biomass from a local area of Roorkee Uttarakhand,which contains siliceous material to a significant extent.Biochar was prepared from agricultural waste in a muffle furnace at a temperature of 500℃for 90 min and ground to a fineness of less than 10μm.Prior to incorporation into building envelopes such as mortar and concrete,a basic study on cement pastes is essentially required.For this purpose,different dosages of biochar such as 0,3%,5%and 10%wt.were replaced with cement in cementitious materials.Physical properties such as water absorption,density and porosity were investigated.Furthermore,mechanical and thermal properties such as compressive strength and thermal conductivity were studied.Advanced tools like field emission scanning electron microscopy(FESEM),X-ray diffraction(XRD)and thermogravimetric analyzer(TGA)were used to identify the hydration products.As the dosages increased in the cement matrix,the physical properties of sample were increased and porosity decreased.The compressive strength of biochar incorporated cement paste improved according to 0,3%,5%and 10%wt.It further reveals that as the dosage increased,the thermal conductivity of the samples decreased significantly.Moreover,the sustainable assessment showed that biochar could reduce embodied carbon,embodied energy and strength efficiency substantially over the control sample.A satisfactory result was obtained at 5%wt.and 10%wt.of biochar.The overall result revealed that biochar up to 10%wt.can be incorporated into mortar and concrete due to better results than the control mix.展开更多
Phosphorus(P)is an essential element for plant growth but is often limiting in ecosystems;therefore,improving the P fertilizer use efficiency is important.Biochar and arbuscular mycorrhizal fungi(AMF)may enhance P cyc...Phosphorus(P)is an essential element for plant growth but is often limiting in ecosystems;therefore,improving the P fertilizer use efficiency is important.Biochar and arbuscular mycorrhizal fungi(AMF)may enhance P cycling in paddy soils that contain high content of total P but low content of available P(AP).In this study,the effects of biochar addition and Rhizophagus irregularis inoculation on the organic and inorganic P contents and phosphatase activities in paddy soils,rice seedling growth,and AMF colonization were investigated.Compared with no biochar addition,biochar addition enhanced the percentage of spore germination at day 7,hyphal length,most probable number,and mycorrhizal colonization rate of R.irregularis by 32%,662%,70%,and 28%on average,respectively.Biochar and R.irregularis altered soil P cycling and availability.Biochar and R.irregularis,either individually or in combination,increased soil AP content by 2%–48%.Rice seedlings treated with biochar and R.irregularis produced greater biomass,improved root morphology,and increased nutrient uptake compared with those of the control without biochar and R.irregularis.The results suggest that combined application of biochar and R.irregularis is beneficial to rice cultivation in paddy soils with high content of total P but low content of AP.展开更多
The Original Belonio Rice Husk Gasifier (OBRHG), initially of height of 0.6 m, diameter of 0.15 m and thickness of 0.025 m was tested for biochar production through air gasification of rice husk (RH) and the design wa...The Original Belonio Rice Husk Gasifier (OBRHG), initially of height of 0.6 m, diameter of 0.15 m and thickness of 0.025 m was tested for biochar production through air gasification of rice husk (RH) and the design was upscaled to height of 1.65 m, diameter of 0.85 m and thickness of 0.16 m. A total of 27 experiments were conducted to monitor the gasifier performance and the system can operate with the centrifugal blower operating at a power input of 155 W and a maximum flow rate of 1450 m3/hr regulated according to the air requirement. Building the UBRHG is simple and inexpensive to fabricate and with the fairly satisfactory performance and ease of construction along with the convenience of operation, the UBRHG with RH as feed would find abundant avenues of applications in a rural setting for biochar production alongside thermal, mechanical and electrical energy delivery.展开更多
文摘Excessive waste production has led to the concept of a circular bioeconomy to deliver valuable by-products and improve environmental sustainability.The annual worldwide rice production accounts for more than 750 million tons of grain and 150 million tons of husk.Rice husk(RH)contains valuable biomaterials with extensive applications in various fields.The proportions of each component depend primarily on rice genotype,soil chemistry,and climatic conditions.RH and its derivatives,including ash,biochar,hydrochar,and activated carbon have been placed foreground of applications in agriculture and other industries.While the investigation on RH’s compositions,microstructures,and by-products has been done copiously,owing to its unique features,it is still an open-ended area with enormous scope for innovation,research,and technology.Here,we reviewed the latest applications of RH and its derivatives,including fuel and other energy resources,construction materials,pharmacy,medicine,and nanobiotechnology to keep this versatile biomaterial in the spotlight.
文摘This paper critically reviewed the current knowledge and challenges of rice husk biochar(RHB)production and its effects on soil properties,plant growth,immobilization of heavy metals,reduction of nutrient leaching and mitigation of greenhouse gas emissions.The characteristics of RHBs produced at various pyrolysis temperatures were discussed and compared to biochars derived from other agro-industrial wastes.RHBs produced at higher pyrolysis temperatures show lower hydrogen/carbon ratio,which suggests the presence of higher aromatic carbon compounds.The increase of pyrolysis temperature also results in production of RHBs with higher ash content,lower yield and higher surface area.RHB usually has higher silicon and ash contents and lower carbon content compared to biochars derived from other feedstocks at the same pyrolysis conditions.Although it depends on soil type,RHB application can improve soil organic carbon content,cation exchange capacity,available K concentration,bulk density and microbial activity.The effect of RHB on soil aggregation mainly depends on soil texture.The growth of different crops is also enhanced by application of RHB.RHB addition to soil can immobilize heavy metals and herbicides and reduce their bioavailability.RHB application shows a significant capacity in reduction of nitrate leaching,although its magnitude depends on the biochar application rate and soil biogeochemical characteristics.Use of RHB,especially in paddy fields,shows a promising mitigation effect on greenhouse gas(CH4,CO2 and N2O)emissions.Although RHB characteristics are also related to other factors such as pyrolysis heating rate and residence time,its performance for specific applications(e.g.carbon sequestration,pH amendment)can be manipulated by adjusting the pyrolysis temperature.More research is needed on long-term field applications of RHB to fully understand the advantages and disadvantages of RHB as a soil amendment.
文摘Incorporating small amounts of biochar into cementitious materials has partial effects on the environment.In this present study,rice husk was collected as agricultural biomass from a local area of Roorkee Uttarakhand,which contains siliceous material to a significant extent.Biochar was prepared from agricultural waste in a muffle furnace at a temperature of 500℃for 90 min and ground to a fineness of less than 10μm.Prior to incorporation into building envelopes such as mortar and concrete,a basic study on cement pastes is essentially required.For this purpose,different dosages of biochar such as 0,3%,5%and 10%wt.were replaced with cement in cementitious materials.Physical properties such as water absorption,density and porosity were investigated.Furthermore,mechanical and thermal properties such as compressive strength and thermal conductivity were studied.Advanced tools like field emission scanning electron microscopy(FESEM),X-ray diffraction(XRD)and thermogravimetric analyzer(TGA)were used to identify the hydration products.As the dosages increased in the cement matrix,the physical properties of sample were increased and porosity decreased.The compressive strength of biochar incorporated cement paste improved according to 0,3%,5%and 10%wt.It further reveals that as the dosage increased,the thermal conductivity of the samples decreased significantly.Moreover,the sustainable assessment showed that biochar could reduce embodied carbon,embodied energy and strength efficiency substantially over the control sample.A satisfactory result was obtained at 5%wt.and 10%wt.of biochar.The overall result revealed that biochar up to 10%wt.can be incorporated into mortar and concrete due to better results than the control mix.
基金financially supported by the Guiding Fund of the Central Government for Local Science and Technology Development,China(No.2023JH6/100100056)the Science and Technology Plan Project of Shenyang,China(No.22317-2-08)the Earmarked Fund for Modern Agroindustry Technology Research System,China(No.CARS-01-52)。
文摘Phosphorus(P)is an essential element for plant growth but is often limiting in ecosystems;therefore,improving the P fertilizer use efficiency is important.Biochar and arbuscular mycorrhizal fungi(AMF)may enhance P cycling in paddy soils that contain high content of total P but low content of available P(AP).In this study,the effects of biochar addition and Rhizophagus irregularis inoculation on the organic and inorganic P contents and phosphatase activities in paddy soils,rice seedling growth,and AMF colonization were investigated.Compared with no biochar addition,biochar addition enhanced the percentage of spore germination at day 7,hyphal length,most probable number,and mycorrhizal colonization rate of R.irregularis by 32%,662%,70%,and 28%on average,respectively.Biochar and R.irregularis altered soil P cycling and availability.Biochar and R.irregularis,either individually or in combination,increased soil AP content by 2%–48%.Rice seedlings treated with biochar and R.irregularis produced greater biomass,improved root morphology,and increased nutrient uptake compared with those of the control without biochar and R.irregularis.The results suggest that combined application of biochar and R.irregularis is beneficial to rice cultivation in paddy soils with high content of total P but low content of AP.
文摘The Original Belonio Rice Husk Gasifier (OBRHG), initially of height of 0.6 m, diameter of 0.15 m and thickness of 0.025 m was tested for biochar production through air gasification of rice husk (RH) and the design was upscaled to height of 1.65 m, diameter of 0.85 m and thickness of 0.16 m. A total of 27 experiments were conducted to monitor the gasifier performance and the system can operate with the centrifugal blower operating at a power input of 155 W and a maximum flow rate of 1450 m3/hr regulated according to the air requirement. Building the UBRHG is simple and inexpensive to fabricate and with the fairly satisfactory performance and ease of construction along with the convenience of operation, the UBRHG with RH as feed would find abundant avenues of applications in a rural setting for biochar production alongside thermal, mechanical and electrical energy delivery.
