The products of monoammonium phosphate containing Cr^3+resulted in disqualification,and further posed a serious threat to ecological environment and human beings.Herein,the porous adsorbent of fluor(calcium silicate)c...The products of monoammonium phosphate containing Cr^3+resulted in disqualification,and further posed a serious threat to ecological environment and human beings.Herein,the porous adsorbent of fluor(calcium silicate)composites(FCSc)was prepared by hydrothermal method using diatomaceous earth,hydrated lime and additive(NaF)as raw materials,which was characterized and used for the removal of Cr^3+from monoammonium phosphate solutions.The effects of different parameters,such as solution pH,initial Cr^3+concentration,temperature and contact time on the adsorption of Cr^3+onto FCSc were investigated in details.The results indicated that the adsorption process was in agreement with the pseudo-second-order kinetic model and Freundlich isotherm.The spontaneous and endothermic nature of the adsorption process was obtained by analyzing various thermodynamic parameters(△G0,△H0,and△S0).In addition,computational monte carlo simulations between Cr3+ions and FCSc were conducted to elucidate the adsorption mechanism.Such kind of porous adsorbent provided a potential application in the removal of impurities from monoammonium phosphate industry.展开更多
The mitogen-activated protein kinase (MAPK) cascade is the most important mechanism in environmental responses and developmental processes in plants. The OsMAPK2 gene has been found to function in plant tolerance to d...The mitogen-activated protein kinase (MAPK) cascade is the most important mechanism in environmental responses and developmental processes in plants. The OsMAPK2 gene has been found to function in plant tolerance to diverse biotic/abiotic stresses. This paper presents evidence that OsMAPK2 (Oryza sativa MAP kinase gene 2) is responsive to Pi deficiency and involved in Pi homeostasis. We found that full-length expression of OsMAPK2 was up-regulated in both rice plants and cell culture in the absence of inorganic phosphate (Pi). The transgenic rice and Arabidopsis plants overexpressing OsMAPK2 showed affected root development and increased plant Pi content compared with wild-type plants. Overexpression of OsMAPK2 controlled the expression of several Pi starvation-responsive genes. Our results indicated that OsMAPK2 enables tolerance phosphate deficiency and is involved in Pi homeostasis.展开更多
Ammonium phosphate fertilizer is the compounds containing nitrogen and phosphorus that are usually produced through the neutralization reaction of phosphoric acid and ammonia.At present,there are a variety of products...Ammonium phosphate fertilizer is the compounds containing nitrogen and phosphorus that are usually produced through the neutralization reaction of phosphoric acid and ammonia.At present,there are a variety of products,such as slurry monoammonium phosphate(MAP),diammonium phosphate(DAP),industrial grade MAP,water soluble MAP,water soluble ammonium polyphosphate(APP)and so on.After more than 60 years of development,China’s ammonium phosphate fertilizer industry has experienced the road of from scratch and from weak to strong.The successful development of the slurry MAP technology ended the history that the high concentration phosphate fertilizer cannot be produced by using the medium and low grade phosphate ore.The continuous,stable and large-scale production of DAP plant provides sufficient guarantee for DAP products in China.The development of new ammonium phosphate fertilizer products,such as industrial grade MAP,water soluble MAP,water soluble APP,provides technical support for the transformation and upgrading of phosphorus chemical enterprises.In this paper,the production methods,the development history and the latest research progress of ammonium phosphate fertilizers were reviewed.展开更多
It is necessary to adjust reaction pH when a single kind of PO3-4 is used as phosphorus source to remove NH+4-N in a chemical precipitation process.However,this tedious step could be avoided in experiments that use th...It is necessary to adjust reaction pH when a single kind of PO3-4 is used as phosphorus source to remove NH+4-N in a chemical precipitation process.However,this tedious step could be avoided in experiments that use the buffering effect of the composite phosphate and employ PO3-4 and HPO2-4 as phosphorus sources.pH was controlled by properly changing the proportion of PO3-4 to HPO2-4.The influences of pH,material proportion and different addition modes of magnesium on NH+4-N removal efficiency were investigated,with NH+4-N concentration in influent being 200mg/L.It showed that the ratio of HPO2-4:PO3-4 was concerned with phosphorus and NH+4-N removal.Under the condition that the total amount of phosphate is definite,the removal efficiency of NH+4-N decreased with the enhancement of HPO2-4 concentration,while the efficiency of phosphorus increased.When increasing PO3-4 concentration,it benefited the removal of NH+4-N,but the remaining phosphorus was high.The results showed that NH+4-N concentration decreased from the initial 200mg/L to 39.14mg/L with the remaining PO3-4 at 5.14mg/L if the ratio of HPO2-4:PO3-4 remained at 1:3.展开更多
基金the National Natural Science Foundation of China(U1633203)the Major Project of the Civil Aviation Administration of China(J2020-108)。
文摘The products of monoammonium phosphate containing Cr^3+resulted in disqualification,and further posed a serious threat to ecological environment and human beings.Herein,the porous adsorbent of fluor(calcium silicate)composites(FCSc)was prepared by hydrothermal method using diatomaceous earth,hydrated lime and additive(NaF)as raw materials,which was characterized and used for the removal of Cr^3+from monoammonium phosphate solutions.The effects of different parameters,such as solution pH,initial Cr^3+concentration,temperature and contact time on the adsorption of Cr^3+onto FCSc were investigated in details.The results indicated that the adsorption process was in agreement with the pseudo-second-order kinetic model and Freundlich isotherm.The spontaneous and endothermic nature of the adsorption process was obtained by analyzing various thermodynamic parameters(△G0,△H0,and△S0).In addition,computational monte carlo simulations between Cr3+ions and FCSc were conducted to elucidate the adsorption mechanism.Such kind of porous adsorbent provided a potential application in the removal of impurities from monoammonium phosphate industry.
文摘The mitogen-activated protein kinase (MAPK) cascade is the most important mechanism in environmental responses and developmental processes in plants. The OsMAPK2 gene has been found to function in plant tolerance to diverse biotic/abiotic stresses. This paper presents evidence that OsMAPK2 (Oryza sativa MAP kinase gene 2) is responsive to Pi deficiency and involved in Pi homeostasis. We found that full-length expression of OsMAPK2 was up-regulated in both rice plants and cell culture in the absence of inorganic phosphate (Pi). The transgenic rice and Arabidopsis plants overexpressing OsMAPK2 showed affected root development and increased plant Pi content compared with wild-type plants. Overexpression of OsMAPK2 controlled the expression of several Pi starvation-responsive genes. Our results indicated that OsMAPK2 enables tolerance phosphate deficiency and is involved in Pi homeostasis.
文摘Ammonium phosphate fertilizer is the compounds containing nitrogen and phosphorus that are usually produced through the neutralization reaction of phosphoric acid and ammonia.At present,there are a variety of products,such as slurry monoammonium phosphate(MAP),diammonium phosphate(DAP),industrial grade MAP,water soluble MAP,water soluble ammonium polyphosphate(APP)and so on.After more than 60 years of development,China’s ammonium phosphate fertilizer industry has experienced the road of from scratch and from weak to strong.The successful development of the slurry MAP technology ended the history that the high concentration phosphate fertilizer cannot be produced by using the medium and low grade phosphate ore.The continuous,stable and large-scale production of DAP plant provides sufficient guarantee for DAP products in China.The development of new ammonium phosphate fertilizer products,such as industrial grade MAP,water soluble MAP,water soluble APP,provides technical support for the transformation and upgrading of phosphorus chemical enterprises.In this paper,the production methods,the development history and the latest research progress of ammonium phosphate fertilizers were reviewed.
文摘It is necessary to adjust reaction pH when a single kind of PO3-4 is used as phosphorus source to remove NH+4-N in a chemical precipitation process.However,this tedious step could be avoided in experiments that use the buffering effect of the composite phosphate and employ PO3-4 and HPO2-4 as phosphorus sources.pH was controlled by properly changing the proportion of PO3-4 to HPO2-4.The influences of pH,material proportion and different addition modes of magnesium on NH+4-N removal efficiency were investigated,with NH+4-N concentration in influent being 200mg/L.It showed that the ratio of HPO2-4:PO3-4 was concerned with phosphorus and NH+4-N removal.Under the condition that the total amount of phosphate is definite,the removal efficiency of NH+4-N decreased with the enhancement of HPO2-4 concentration,while the efficiency of phosphorus increased.When increasing PO3-4 concentration,it benefited the removal of NH+4-N,but the remaining phosphorus was high.The results showed that NH+4-N concentration decreased from the initial 200mg/L to 39.14mg/L with the remaining PO3-4 at 5.14mg/L if the ratio of HPO2-4:PO3-4 remained at 1:3.
