A new technique was introduced for sand stabilization and re-vegetation by use of lignin sand stabilizing material(LSSM). LSSM is a reconstructed organic compound with lignin as the most dominant component from the ex...A new technique was introduced for sand stabilization and re-vegetation by use of lignin sand stabilizing material(LSSM). LSSM is a reconstructed organic compound with lignin as the most dominant component from the extracts of black-liquor issued by straw pulp paper mills. Unlike the polyvinyl acetate or foamed asphalt commonly used for dune stabilization, the new material is plant-friendly and can be used with virescence actions simultaneously. The field experimental study was conducted since 2001 in China's Northwest Ningxia Hui Autonomous Region and has been proved that LSSM is effective in stabilizing the fugitive dunes, making the arenaceous plants survive and the bare dune vegetative. The advisable solution concentration is 2% and the optimal field spraying quantity is 2 5 L/m^2 The soil nutrients of the stabilized and greened dune, such as organic matter, available phosphorous and total nitrogen are all increased compared with the control treatment, which is certainly helpful to the growth of arenaceous plants. The technique is worthwhile to be popularized because it is provided not only a new method for desertification control but also an outlet for cleaning contaminants issued from the straw paper mills.展开更多
TOC and color in the bleaching effluent from straw pulp paper process could not reach draining standard after its treatment by a biochemical process. In this study, advanced treatment by integrated micro-electrolysis ...TOC and color in the bleaching effluent from straw pulp paper process could not reach draining standard after its treatment by a biochemical process. In this study, advanced treatment by integrated micro-electrolysis （Fe^0） method and Fenton-like process was investigated under various conditions, i.e. pH, Fe/C ratio, initial I-I2O2 concentration and carrier gas. Results showed that Fe/C ratio（V/V = 1.5）, larger H2O2 dosage around 50 rag/L, lower pH（pH= 3） turned out to be particularly efficient. Temperature was a key parameter, remarkably increasing reaction rates. Carrier air not only improved reaction efficiency, but also saved H2O2 dosage. Chlorinated organic compounds could be reductive dechlorinated by Fe^0 reaction and oxidated by OH produced from Fenton process. The combination of Fe^0 and H2O2 reactions had been proved to be highly effective for the advanced treatment of such a type of wastewaters, and important advantages concerning the application in the study.展开更多
A magnesia adsorbent was prepared from straw pulp black liquor and magnesium sulfate for the first time, and its adsorption of phenol from aqueous solution was examined. The characteristics of the adsorbent were teste...A magnesia adsorbent was prepared from straw pulp black liquor and magnesium sulfate for the first time, and its adsorption of phenol from aqueous solution was examined. The characteristics of the adsorbent were tested through chemical analysis, surface analysis, X-ray diffraction and FT-IR spectroscopy. The effects of various factors, such as dose, adsorption time and adsorption temperature, on phenol adsorption behavior were studied. The results show that the adsorption processes can be fitted to the isotherm Langmuir model very well. It was found that the adsorption process was strongly influenced by temperature and the optimal temperature for phenol removal was 40 ℃. The optimum adsorption time was 10 min, and desorption would happen afterwards. Between the models of Langmuir and Freundlich, the adsorption process of phenol onto magnesia fitted the Langmuir equation better.展开更多
A pulping method using NH4OH with less amount of KOH as cooking liquor on wheat straw was developed. KOH could reduce consumption of NH3 and cooking time for its strong alkalinity. The effects of various pulping condi...A pulping method using NH4OH with less amount of KOH as cooking liquor on wheat straw was developed. KOH could reduce consumption of NH3 and cooking time for its strong alkalinity. The effects of various pulping conditions such as composition of cooking liquor, liquid-to-solid ratio, maximum temperature, cooking time to the maximum temperature and cooking time at the maximum temperature were studied. Experimental results indicated that the rate of delignification was 85.12% and the pulp yield was 49.65% under suitable pulping conditions. It looks promising to use black liquor containing nitrogen, phosphorus, potassium and organic substance as fertilizer resources for agricultural production. A new pattern of ecological cycling may be set up between paper industry and farming.展开更多
The various properties of bentonite samples with different sources and their synergistic retention effect with CPAM on wheat straw pulps were investigated. The investigated properties of bentonite included adsorptive ...The various properties of bentonite samples with different sources and their synergistic retention effect with CPAM on wheat straw pulps were investigated. The investigated properties of bentonite included adsorptive capacity based on methylene blue, cation-exchange capacity, swelling volume, colloidal volume, particle size and charge properties. The results show that particle size is the most important properties of bentonite for its synergistic retention effect with CPAM. Using Wyoming type sodium bentonite without drying after modification can obtain the excellent furnishes retention.展开更多
Coordinated pretreatment of xylanase and laccase on Soda-AQ wheat straw pulp before CEH bleaching was studied. Results show: Pretreatment of xylanase and laccase has better effect than of sole xylanase and sole laccas...Coordinated pretreatment of xylanase and laccase on Soda-AQ wheat straw pulp before CEH bleaching was studied. Results show: Pretreatment of xylanase and laccase has better effect than of sole xylanase and sole laccase; Coordination can increase pulp brightness and bleachability, improve pulp filterability of water, lighten degree of effluent pollution in bleaching workshop, and develop overall strength properties of bleached pulp.展开更多
The influences on the brightness, viscosity and Kappa of the straw pulp under the different oxygen-alkali bleaching conditions have been studied in this paper.
Before calcium hypochlorite bleaching (H) and chlorination,alkaline extraction, calcium hypochlorite three-stage-bleaching (CEH),we used a kind of hemicellulase, xylanase, to treat wheat straw pulp from Gaoyou Papermi...Before calcium hypochlorite bleaching (H) and chlorination,alkaline extraction, calcium hypochlorite three-stage-bleaching (CEH),we used a kind of hemicellulase, xylanase, to treat wheat straw pulp from Gaoyou Papermill. Xylanase pretreatment contained tow stages, the first stage was xylanase treatment, which was followed by alkaline extraction, the second stage. The xylanase could act on partial lignin and carbohydrate, chiefly xylan. The following alkaline extraction could dissolve something that could not be removed during the first stage. The result of pretreatment was to facilitate penetration of bleaching chemicals, to reduce effective chlorine consumption and to lower pollution loading of bleaching effluent. In the case of these two bleaching processes, the enzymatic pretreatment substantially enhanced the optical properties of the pulps. To calcium hypochlorite bleaching, strength properties of pulps were improved.展开更多
Thick black liquor, thin black liquor and solid state sodium hydroxide are added to the liquor treated by sulfur dioxide, then the blended liquor is used to recycle cooking of straw pulp. The black liquor, separated l...Thick black liquor, thin black liquor and solid state sodium hydroxide are added to the liquor treated by sulfur dioxide, then the blended liquor is used to recycle cooking of straw pulp. The black liquor, separated liquor and pulp of every cycles are analyzed respectively. Result shows that the content of lignin and organism in recycle black liquor and separated liquor increases faster in the first three cycles and then continues to increase slowly till four or five times, after that it trends to a stable state. The main organism separated from waste liquor of AS-AQ treated by sulfur dioxide is alkali-lignin, above 50% of total lignin in black liquor. The yield of pulp made from recycle cooking is steady, the hardness of pulp has a great improvement with recycle cooking. The brightness of pulp reduces correspondingly before bleaching, and after bleaching the brightness of pulp is relatively high and steady at the same sodium hypo chlorite dosage.展开更多
Long-time fermentation has always been one of the reasons restricting the development of straw biological pulping.This study aimed to develop a novel straw pulp film with shortened solid-state fermentation time with l...Long-time fermentation has always been one of the reasons restricting the development of straw biological pulping.This study aimed to develop a novel straw pulp film with shortened solid-state fermentation time with less than 20%mass loss rate by bio-pulping synergistic treatment of straw fibers with deep eutectic solvent(DES)and Streptomyces rochei(S.rochei).Results illustrated that at 3%S.rochei concentration with 7-day fermentation,both cellulose and hemicellulose enzyme activities of the treated rice straw fiber reached peak values with a fiber mass loss rate of 17.01%.Microstructural morphology revealed that S.rochei colonization initiated on straw surfaces and progressively penetrated internal structures,resulting in surface loosening and distinct disruption of cell wall tissues within vascular bundles in transverse sections.The treated rice straw strip indicated a maximum tensile strength of 46.22 MPa for(Bacteria)BA 3%at day 7,attributed to optimized synergistic effects of microfibril angle(MFA)and cellulose/hemicellulose relative content ratio.The modified straw pulp film exhibited significant enhancement in the tensile index(44.9%increase),burst index(10.3%increase),and tear index(60%increase)compared to untreated groups.This work demonstrated the important role ofDES and S.rochei bio-pulping synergistic treatment in improving rice straw pulp performance,suggesting an eco-friendly,novel,and efficient biomass pretreatment technology for potential application prospects in sustainable agricultural mulching materials.展开更多
A pulping technology of wheat straw with aqueous ammonia and diluent caustic potash was investigated. Because its strong alkalinity, the addition of caustic potash not only reduced the quantity of NH3 consumed and coo...A pulping technology of wheat straw with aqueous ammonia and diluent caustic potash was investigated. Because its strong alkalinity, the addition of caustic potash not only reduced the quantity of NH3 consumed and cooking time, but also enriched the black liquor with nutrients such as potassium and nitrogen, which could be used as fertilizer for agriculture. Various pulping conditions including composition of cooking liquor, liquor-to-solid ratio, maximum cooking temperature, time to reach the maximum temperature and time at the maximum temperature were studied systematically to determine the suitable pulping conditions. Results of the cooking course showed that there were three distinct delignification phases, namely, the bulk delignification phase from the beginning of cook- ing to 100℃, the supplementary delignification phase from 100℃ to 155℃ for 45min and the third delignification phase till the end of cooking. The rate of delignification was found to be first order with respect to residual lignin and 0.34 order with respect to [OH - ]. The activation energy of the delignification reaction was 29.75kJ·mol-1 and the rate equation of delignification was also obtained.展开更多
Wheat straw was cut into a certain size range and treated with a strain of the white rot fungus Phanerochatete Chrysosporium for 5 days before subjected to a chemi-mechanical treatment. Chemical analyses revealed the ...Wheat straw was cut into a certain size range and treated with a strain of the white rot fungus Phanerochatete Chrysosporium for 5 days before subjected to a chemi-mechanical treatment. Chemical analyses revealed the effects of the white rot fungus on the wheat straw components. SEM was applied to observe the changes in fiber micromorphological structures. CODcr of the effluent from the sulfonation treatment of wheat straw was also discussed. Handsheets made from the treated and untreated wheat straw exhibited different optical and physical properties after chemi-mechanical pulping.展开更多
In this study,wheat straw pulp was prepared by sulfiteformaldehyde(SF) pulping combined with oxygen delignification to develop a sustainable methodology for chemical pulping of straw materials.The bleachability of oxy...In this study,wheat straw pulp was prepared by sulfiteformaldehyde(SF) pulping combined with oxygen delignification to develop a sustainable methodology for chemical pulping of straw materials.The bleachability of oxygen-delignified SF pulp was also evaluated by hypochlorite bleaching.The results indicated that the Na_2SO_3 charge played an important role in lignin removal during SF pulping as well as oxygen delignification.The efficiency of oxygen delignification of wheat straw SF pulp was markedly high.After the oxygenation stage,the Kappa number decreased by over 50%(the original Kappa number of SF pulp was lower than 30) when the Na OH charge was in the range of 3%~5%.The optimal conditions for preparing bleached pulp via combined SF pulping and oxygen delignification involved the use of 12% of Na_2SO_3 and 3% of Na OH,respectively.Pulp with relatively high brightness,a low Kappa number,as well as an acceptable viscosity could be obtained when oxygen-delignified SF pulp was bleached with hypochlorite under a low active chlorine dosage.展开更多
The measurement of lignin content in black liquid of straw AS-AQ by ultraviolet spectrophotometer(UV) is discussed in this paper. Different dilution multiple and contrast solutions have an effect on the measured resul...The measurement of lignin content in black liquid of straw AS-AQ by ultraviolet spectrophotometer(UV) is discussed in this paper. Different dilution multiple and contrast solutions have an effect on the measured results of the lignin content by UV. The calculation method for the absorption coefficient and the scanning spectrum property of liquor acidified by SO2 are introduced in this paper.展开更多
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
文摘A new technique was introduced for sand stabilization and re-vegetation by use of lignin sand stabilizing material(LSSM). LSSM is a reconstructed organic compound with lignin as the most dominant component from the extracts of black-liquor issued by straw pulp paper mills. Unlike the polyvinyl acetate or foamed asphalt commonly used for dune stabilization, the new material is plant-friendly and can be used with virescence actions simultaneously. The field experimental study was conducted since 2001 in China's Northwest Ningxia Hui Autonomous Region and has been proved that LSSM is effective in stabilizing the fugitive dunes, making the arenaceous plants survive and the bare dune vegetative. The advisable solution concentration is 2% and the optimal field spraying quantity is 2 5 L/m^2 The soil nutrients of the stabilized and greened dune, such as organic matter, available phosphorous and total nitrogen are all increased compared with the control treatment, which is certainly helpful to the growth of arenaceous plants. The technique is worthwhile to be popularized because it is provided not only a new method for desertification control but also an outlet for cleaning contaminants issued from the straw paper mills.
文摘TOC and color in the bleaching effluent from straw pulp paper process could not reach draining standard after its treatment by a biochemical process. In this study, advanced treatment by integrated micro-electrolysis （Fe^0） method and Fenton-like process was investigated under various conditions, i.e. pH, Fe/C ratio, initial I-I2O2 concentration and carrier gas. Results showed that Fe/C ratio（V/V = 1.5）, larger H2O2 dosage around 50 rag/L, lower pH（pH= 3） turned out to be particularly efficient. Temperature was a key parameter, remarkably increasing reaction rates. Carrier air not only improved reaction efficiency, but also saved H2O2 dosage. Chlorinated organic compounds could be reductive dechlorinated by Fe^0 reaction and oxidated by OH produced from Fenton process. The combination of Fe^0 and H2O2 reactions had been proved to be highly effective for the advanced treatment of such a type of wastewaters, and important advantages concerning the application in the study.
基金the financial support from the Natural Science Foundation of China (No. 20477041)
文摘A magnesia adsorbent was prepared from straw pulp black liquor and magnesium sulfate for the first time, and its adsorption of phenol from aqueous solution was examined. The characteristics of the adsorbent were tested through chemical analysis, surface analysis, X-ray diffraction and FT-IR spectroscopy. The effects of various factors, such as dose, adsorption time and adsorption temperature, on phenol adsorption behavior were studied. The results show that the adsorption processes can be fitted to the isotherm Langmuir model very well. It was found that the adsorption process was strongly influenced by temperature and the optimal temperature for phenol removal was 40 ℃. The optimum adsorption time was 10 min, and desorption would happen afterwards. Between the models of Langmuir and Freundlich, the adsorption process of phenol onto magnesia fitted the Langmuir equation better.
文摘A pulping method using NH4OH with less amount of KOH as cooking liquor on wheat straw was developed. KOH could reduce consumption of NH3 and cooking time for its strong alkalinity. The effects of various pulping conditions such as composition of cooking liquor, liquid-to-solid ratio, maximum temperature, cooking time to the maximum temperature and cooking time at the maximum temperature were studied. Experimental results indicated that the rate of delignification was 85.12% and the pulp yield was 49.65% under suitable pulping conditions. It looks promising to use black liquor containing nitrogen, phosphorus, potassium and organic substance as fertilizer resources for agricultural production. A new pattern of ecological cycling may be set up between paper industry and farming.
文摘The various properties of bentonite samples with different sources and their synergistic retention effect with CPAM on wheat straw pulps were investigated. The investigated properties of bentonite included adsorptive capacity based on methylene blue, cation-exchange capacity, swelling volume, colloidal volume, particle size and charge properties. The results show that particle size is the most important properties of bentonite for its synergistic retention effect with CPAM. Using Wyoming type sodium bentonite without drying after modification can obtain the excellent furnishes retention.
文摘Coordinated pretreatment of xylanase and laccase on Soda-AQ wheat straw pulp before CEH bleaching was studied. Results show: Pretreatment of xylanase and laccase has better effect than of sole xylanase and sole laccase; Coordination can increase pulp brightness and bleachability, improve pulp filterability of water, lighten degree of effluent pollution in bleaching workshop, and develop overall strength properties of bleached pulp.
文摘The influences on the brightness, viscosity and Kappa of the straw pulp under the different oxygen-alkali bleaching conditions have been studied in this paper.
文摘Before calcium hypochlorite bleaching (H) and chlorination,alkaline extraction, calcium hypochlorite three-stage-bleaching (CEH),we used a kind of hemicellulase, xylanase, to treat wheat straw pulp from Gaoyou Papermill. Xylanase pretreatment contained tow stages, the first stage was xylanase treatment, which was followed by alkaline extraction, the second stage. The xylanase could act on partial lignin and carbohydrate, chiefly xylan. The following alkaline extraction could dissolve something that could not be removed during the first stage. The result of pretreatment was to facilitate penetration of bleaching chemicals, to reduce effective chlorine consumption and to lower pollution loading of bleaching effluent. In the case of these two bleaching processes, the enzymatic pretreatment substantially enhanced the optical properties of the pulps. To calcium hypochlorite bleaching, strength properties of pulps were improved.
文摘Thick black liquor, thin black liquor and solid state sodium hydroxide are added to the liquor treated by sulfur dioxide, then the blended liquor is used to recycle cooking of straw pulp. The black liquor, separated liquor and pulp of every cycles are analyzed respectively. Result shows that the content of lignin and organism in recycle black liquor and separated liquor increases faster in the first three cycles and then continues to increase slowly till four or five times, after that it trends to a stable state. The main organism separated from waste liquor of AS-AQ treated by sulfur dioxide is alkali-lignin, above 50% of total lignin in black liquor. The yield of pulp made from recycle cooking is steady, the hardness of pulp has a great improvement with recycle cooking. The brightness of pulp reduces correspondingly before bleaching, and after bleaching the brightness of pulp is relatively high and steady at the same sodium hypo chlorite dosage.
基金funded by the Agricultural Science and Technology Innovation Fund of Jiangsu Province[Grant/Award Number:CX(24)1008]Key Research and Development Program Project of Henan Province(251111110100)National State Science Foundation of China[Grant/Award Number:21808093].
文摘Long-time fermentation has always been one of the reasons restricting the development of straw biological pulping.This study aimed to develop a novel straw pulp film with shortened solid-state fermentation time with less than 20%mass loss rate by bio-pulping synergistic treatment of straw fibers with deep eutectic solvent(DES)and Streptomyces rochei(S.rochei).Results illustrated that at 3%S.rochei concentration with 7-day fermentation,both cellulose and hemicellulose enzyme activities of the treated rice straw fiber reached peak values with a fiber mass loss rate of 17.01%.Microstructural morphology revealed that S.rochei colonization initiated on straw surfaces and progressively penetrated internal structures,resulting in surface loosening and distinct disruption of cell wall tissues within vascular bundles in transverse sections.The treated rice straw strip indicated a maximum tensile strength of 46.22 MPa for(Bacteria)BA 3%at day 7,attributed to optimized synergistic effects of microfibril angle(MFA)and cellulose/hemicellulose relative content ratio.The modified straw pulp film exhibited significant enhancement in the tensile index(44.9%increase),burst index(10.3%increase),and tear index(60%increase)compared to untreated groups.This work demonstrated the important role ofDES and S.rochei bio-pulping synergistic treatment in improving rice straw pulp performance,suggesting an eco-friendly,novel,and efficient biomass pretreatment technology for potential application prospects in sustainable agricultural mulching materials.
基金the Natural Science Foundation of Jiangxi Province (No.0520003).
文摘A pulping technology of wheat straw with aqueous ammonia and diluent caustic potash was investigated. Because its strong alkalinity, the addition of caustic potash not only reduced the quantity of NH3 consumed and cooking time, but also enriched the black liquor with nutrients such as potassium and nitrogen, which could be used as fertilizer for agriculture. Various pulping conditions including composition of cooking liquor, liquor-to-solid ratio, maximum cooking temperature, time to reach the maximum temperature and time at the maximum temperature were studied systematically to determine the suitable pulping conditions. Results of the cooking course showed that there were three distinct delignification phases, namely, the bulk delignification phase from the beginning of cook- ing to 100℃, the supplementary delignification phase from 100℃ to 155℃ for 45min and the third delignification phase till the end of cooking. The rate of delignification was found to be first order with respect to residual lignin and 0.34 order with respect to [OH - ]. The activation energy of the delignification reaction was 29.75kJ·mol-1 and the rate equation of delignification was also obtained.
文摘Wheat straw was cut into a certain size range and treated with a strain of the white rot fungus Phanerochatete Chrysosporium for 5 days before subjected to a chemi-mechanical treatment. Chemical analyses revealed the effects of the white rot fungus on the wheat straw components. SEM was applied to observe the changes in fiber micromorphological structures. CODcr of the effluent from the sulfonation treatment of wheat straw was also discussed. Handsheets made from the treated and untreated wheat straw exhibited different optical and physical properties after chemi-mechanical pulping.
基金financial support from the China Postdoctoral Science Foundation(Grant No.2016M591853)the Foundation of the State Key Laboratory of Pulp and Paper Engineering,China(Grant No.201616)+1 种基金the Youth Science and Technology Innovation Fund of Nanjing Forestry University,China(CX2015015)the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘In this study,wheat straw pulp was prepared by sulfiteformaldehyde(SF) pulping combined with oxygen delignification to develop a sustainable methodology for chemical pulping of straw materials.The bleachability of oxygen-delignified SF pulp was also evaluated by hypochlorite bleaching.The results indicated that the Na_2SO_3 charge played an important role in lignin removal during SF pulping as well as oxygen delignification.The efficiency of oxygen delignification of wheat straw SF pulp was markedly high.After the oxygenation stage,the Kappa number decreased by over 50%(the original Kappa number of SF pulp was lower than 30) when the Na OH charge was in the range of 3%~5%.The optimal conditions for preparing bleached pulp via combined SF pulping and oxygen delignification involved the use of 12% of Na_2SO_3 and 3% of Na OH,respectively.Pulp with relatively high brightness,a low Kappa number,as well as an acceptable viscosity could be obtained when oxygen-delignified SF pulp was bleached with hypochlorite under a low active chlorine dosage.
文摘The measurement of lignin content in black liquid of straw AS-AQ by ultraviolet spectrophotometer(UV) is discussed in this paper. Different dilution multiple and contrast solutions have an effect on the measured results of the lignin content by UV. The calculation method for the absorption coefficient and the scanning spectrum property of liquor acidified by SO2 are introduced in this paper.
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.
