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This work reports the application of an electromembrane process, Donnan dialysis (DD), for the purification of so-called wet-process phosphoric acid (WPA). Nitric acid is used as the stripping solution to remove metallic cations (mostly Fe3+, Al3+, and Mg2+) that are harmful to the further processing of WPA. The paper first presents a set of experimental data on the measurements of the metallic cation fluxes through a perfluorinated sulfonic acid cation-exchange membrane. Not only WPA, but also synthetic phosphoric acid solutions with mixed metallic cations (MPA) and with a single metallic cation (SPA) were studied. This confrontation confirms (1) that the order of metallic cations fluxes is Mg2+ > Al3+ > Fe3+; (2) that, compared with MPA, the purification effect of WPA causes only negligible change; (3) that, by comparing the DD processes with SPA and MPA solutions, the reason for the low transmembrane fluxes of Fe3+ and Al3+ could be explained by the large ionic charge and large hydrated ion radius. Furthermore, by analyzing the ion composition of membranes equilibrated in SPA solutions, we conclude that the forms of cations in the membrane are most likely Fe3+, Al3+, and Mg2+.
Qin Zhong; Tao Luo; Zhengjuan Yan; Lin Yang; Zhiye Zhang; Xinlong Wang. Purification of Wet-Process Phosphoric Acid via Donnan Dialysis with a Perfluorinated Sulfonic Acid Cation-Exchange Membrane. Membranes 2021, 11, 298 .
AMA StyleQin Zhong, Tao Luo, Zhengjuan Yan, Lin Yang, Zhiye Zhang, Xinlong Wang. Purification of Wet-Process Phosphoric Acid via Donnan Dialysis with a Perfluorinated Sulfonic Acid Cation-Exchange Membrane. Membranes. 2021; 11 (4):298.
Chicago/Turabian StyleQin Zhong; Tao Luo; Zhengjuan Yan; Lin Yang; Zhiye Zhang; Xinlong Wang. 2021. "Purification of Wet-Process Phosphoric Acid via Donnan Dialysis with a Perfluorinated Sulfonic Acid Cation-Exchange Membrane." Membranes 11, no. 4: 298.
Water contamination is often reported in agriculturally intensive areas such as the Indo-Gangetic Plain (IGP) in south-eastern Asia. We evaluated the impact of the organic and conventional farming of basmati rice on water quality during the rainy season (July to October) of 2011 and 2016 at Kaithal, Haryana, India. The study area comprised seven organic and seven conventional fields where organic farming has been practiced for more than two decades. Water quality parameters used for drinking (nitrate, NO3; total dissolved solids (TDS); electrical conductivity (EC) pH) and irrigation (sodium adsorption ratio (SAR) and residual sodium carbonate (RSC)) purposes were below permissible limits for all samples collected from organic fields and those from conventional fields over the long-term (~15 and ~20 years). Importantly, the magnitude of water NO3 contamination in conventional fields was approximately double that of organic fields, which is quite alarming and needs attention in future for farming practices in the IGP in south-eastern Asia.
Debjani Sihi; Biswanath Dari; Zhengjuan Yan; Dinesh Kumar Sharma; Himanshu Pathak; Om Prakash Sharma; Lata Nain. Assessment of Water Quality in Indo-Gangetic Plain of South-Eastern Asia under Organic vs. Conventional Rice Farming. Water 2020, 12, 960 .
AMA StyleDebjani Sihi, Biswanath Dari, Zhengjuan Yan, Dinesh Kumar Sharma, Himanshu Pathak, Om Prakash Sharma, Lata Nain. Assessment of Water Quality in Indo-Gangetic Plain of South-Eastern Asia under Organic vs. Conventional Rice Farming. Water. 2020; 12 (4):960.
Chicago/Turabian StyleDebjani Sihi; Biswanath Dari; Zhengjuan Yan; Dinesh Kumar Sharma; Himanshu Pathak; Om Prakash Sharma; Lata Nain. 2020. "Assessment of Water Quality in Indo-Gangetic Plain of South-Eastern Asia under Organic vs. Conventional Rice Farming." Water 12, no. 4: 960.
Understanding soil P transformation is critical to optimizing P supply to crops while minimizing P loss to water. Nitrogen application in agricultural fields can cause acidification, changing soil chemistry and altering P cycling. In a calcareous vegetable field in China, 13 years of N application (1172 kg N ha−1 year−1) significantly decreased soil pH, CaCO3, and Mehlich-3 extractable (M3) Mg and increased M3-Fe and M3-Al. Nitrogen addition also increased microbial biomass C (MBC), decreased alkaline phosphomonoesterase (ALP) activity, and changed the total bacterial and phoD-harboring bacterial community composition. Soil total P, Olsen-P, and M3-P were not affected by N fertilization, but there were significant increases in soil total organic P (Po), NaOH-extractable Po, and the proportion of orthophosphate diesters. Redundancy analysis showed that soil pH, organic C, CaCO3, and ALP activity had significant effects on the compositions of soil P form (P < 0.05) and could explain 36.4, 13.3, 27.5, and 10.6% of the total variances observed in the composition of P forms. This suggests that soil acidification from N application in this P-rich calcareous soil altered soil abiotic P cycling processes through increasing the chemical adsorption of Po by Fe and Al. It also altered biotic P cycling processes by increasing microbial P uptake and immobilization and decreasing P biochemical mineralization, resulting in Po accumulation.
Shuo Chen; Zhengjuan Yan; Shuai Zhang; Bingqian Fan; Barbara J. Cade-Menun; Qing Chen. Nitrogen application favors soil organic phosphorus accumulation in calcareous vegetable fields. Biology and Fertility of Soils 2019, 55, 481 -496.
AMA StyleShuo Chen, Zhengjuan Yan, Shuai Zhang, Bingqian Fan, Barbara J. Cade-Menun, Qing Chen. Nitrogen application favors soil organic phosphorus accumulation in calcareous vegetable fields. Biology and Fertility of Soils. 2019; 55 (5):481-496.
Chicago/Turabian StyleShuo Chen; Zhengjuan Yan; Shuai Zhang; Bingqian Fan; Barbara J. Cade-Menun; Qing Chen. 2019. "Nitrogen application favors soil organic phosphorus accumulation in calcareous vegetable fields." Biology and Fertility of Soils 55, no. 5: 481-496.