Environmental Technology & Innovation
·
2022
·
IF 7.758
Yingnan Wang,Zhanbin Huang,Linlin Sheng,Mengmeng Zhao,Junyi Feng
Humic acid (HA) has led to promising developments in the improvement of soil remediation. The low utilization efficiency of the residue produced in the proceeding of HA production causes environmental pollution and the waste of resources. The humic acid residue (HAS) was used as the feedstock for the preparation of an NH 4 H 2 PO 4 modified material (NH 4 H 2 PO 4 -HAS) adsorbent for the adsorption of Pb 2 + in aqueous solutions. Response surface methodology (RSM) using the Box-Behnken design(BBD) to investigate the effects of concentration, temperature, and volume on the adsorption effectiveness of Pb 2 + by the modified material. The optimal parameters of the modified materials are as follows: concentration of NH 4 H 2 PO 4 3%volume 27.7 mL, temperature 71.8 °C. The adsorption equilibrium shows a well fit with the Langmuir isotherm model. The maximum adsorption amounts of Pb 2 + by HAS and NH 4 H 2 PO 4 -HAS composites were 272.185 mg/g and 343.166 mg/g, respectively; the kinetic adsorption data of HAS and NH 4 H 2 PO 4 -HAS exhibit a well fit with the pseudo-second-order model. The desorption of NH 4 H 2 PO 4 -HAS was less than that of HAS at different temperatures and pH. The thermodynamic parameters, Δ Hº, Δ Gº, and Δ Sº, obtained from the isotherm data indicate that the process of Pb 2 + adsorption by HAS and NH 4 H 2 PO 4 -HAS is spontaneous and the uptake of Pb 2 + by HAS and NH 4 H 2 PO 4 -HAS composite is more favored at high temperatures. The adsorption mechanism of NH 4 H 2 PO 4 -HAS on Pb 2 + mainly includes physical adsorption, surface complexation adsorption, and precipitation.
研究领域:
环境科学
·
土壤修复
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2023
·
IF 3.8
Yingnan Wang,Zhen Huang,Linlin Sheng,An Wang,Zhanbin Huang
Humic acid residue (HAS), as a waste product from the extraction of humic acid from low-rank coal such as weathered coal and lignite, is characterized by its abundant yield and low price. However, the low efficiency and high pH value of HAS in passivating heavy metals limit their application in the passivation of heavy metals in soils. To improve the passivation efficiency of humic acid residues against heavy metals, in this study, modified humic acid residues (N-HAS) were prepared by pretreatment with HNO 3 and modification with NH 4 H 2 PO 4 . The results showed that the passivation efficiency of N-HAS was up to 87.75% and 57.07% for Hg and Pb in the effective state, and the adsorption kinetics were under the pseudo-second-order model. The addition of N-HAS to the soil resulted in a change in the morphology of the heavy metals, with the acid extractable state of Hg and Pb reduced by 66.92% and 30.44% respectively, and the results of the Toxicity Leaching Test (TCLP) showed that the addition of N-HAS significantly reduced the leaching toxicity and potential ecological risk index (RI). The soil physicochemical properties changed after the addition of N-HAS and there was a correlation between the soil physicochemical properties and the effective state of Hg and Pb content. In conclusion, N-HAS has a positive effect on the remediation of heavy metal-contaminated soil and has a broad application prospect.
研究领域:
环境科学
·
土壤学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2020
·Vol. 10
·期 30
·17686-17693
·
IF 3.119
Yonghao Tan,Lin Sha,Nengkui Yu,Zhengshuo Yang,Jun Qu,Zhigao Xu
In this study, a citric acid-soluble fertilizer of dittmarite (NH4MgPO4·H2O) was synthesized by balling talc with NH4H2PO4. The effects of ball milling speed and milling time on the dissolution rates of N, P and Mg in deionized water and 2% citric acid were explored. Characterization technologies such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TG) and Scanning electron microscopy (SEM) were applied to test the prepared samples. In water, the prepared dittmarite was changed into struvite (NH4MgPO4·6H2O) with almost no N, P or Mg release, while the dissolution rates of nutrient elements reached almost 100% in 2% citric acid. The proposed work presented a facile and environmentally friendly method to produce CASF with high agricultural and ecological value.
研究领域:
化学工程
·
材料科学
·
农业化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Physical Chemistry Letters
·
2020
·
IF 6.71
Lei Meng,Chen He,Wei Ji,Fei Yen
We observe sharp step-down discontinuities in the magnetic susceptibility of NH4H2PO4 and NH4H2PO4-d60 (60% deuterated) along the a- and c-axes occurring exactly at their antiferroelectric transition temperatures. For the case of KH2PO4, less pronounced discontinuities occur at the ferroelectric transition temperature. To explain this, we treat the acid protons as individual oscillators that generate current elements that translate to magnetic forces in near resonance with each other. With decreasing temperature, the resonant forces become more commensurate, which amplifies a disproportionate drop off of two types of magnetic forces to eventually trigger the structural phase transitions. For the case of NH4H2PO4, the associated internal magnetic field appears to aid the NH4+ to order at a higher temperature. At 49 K, a shoulder-like anomaly in both NH4H2PO4 and KH2PO4 is attributed to a possible onset of macroscopic quantum tunneling of protons. Our findings bring forth a new category of intrinsic multiferroic systems.
研究领域:
凝聚态物理
·
材料科学
·
固态物理
·
磁学
·
铁电学
✓ 已验证
DOI
高影响因子
STAR Protocols
·
2023
·
IF 0
Shuchao Jiang,Jikai Sun,Guoqing Ren,Weiqiao Deng
Summary CO 2 capture and utilization into liquid fuels and high-added-value chemicals has been regarded as an attractive strategy to mitigate excessive carbon emissions. Here, we present a protocol to capture and convert CO 2 into pure formic acid (HCOOH) solution and solid fertilizer (NH 4 H 2 PO 4 ). We describe steps for synthesis of an IRMOF3-derived carbon-supported PdAu heterogeneous catalyst (PdAu/CN-NH 2 ), which can efficiently catalyze (NH 4 ) 2 CO 3 -captured CO 2 into formate under ambient conditions. For complete details on the use and execution of this protocol, please refer to Jiang et al. (2023). 1
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
PubMed
JOURNAL OF THE ENERGY INSTITUTE
·
2021
·
IF 6.186
Youjian Zhu,Yun Liu,Liang Wang,Wei Yang,Haiping Yang,Long Jiang,Zhenyi Du,Jingai Shao,Hanping Chen
Combustion of agricultural residues for heat and electricity production is an efficient way to reduce amount of such waste source and emissions due to inappropriate treatment of them. However, unlike other biomass materials, agricultural residues often have high content of ash and certain ash forming elements with low meting temperatures, resulting in sintering and slagging during combustion processes . It complicates combustion of agricultural residues and restricts further utilization of this renewable energy source . In this work, sintering of a typical agricultural biomass cornstalk and effect of two phosphate additives, Ca(H 2 PO 4 ) 2 ·H 2 O and NH 4 H 2 PO 4 , were investigated by a combination of various techniques. Results indicated that the addition of Ca(H 2 PO 4 ) 2 ·H 2 O increased the initial melting temperature of cornstalk ash by 64–209 °C. The ash sintering behavior was greatly improved as a result of formation of high melting temperature K–Ca phosphates, Ca 9 MgK(PO 4 ) 7 and Ca 2 KP 3 O 10 upon addition of the Ca(H 2 PO 4 ) 2 ·H 2 O. It is accompanied with reduced generation of low melting temperature K-rich silicates and the formation of large ash aggregates. Addition of NH 4 H 2 PO 4 increased the initial ash melting temperature by 28–116 °C, but it had slight influence on the cornstalk ash sintering characteristics. The analysis revealed that, although the addition of NH 4 H 2 PO 4 resulted in the formation of high melting temperature K 2 CaP 2 O 7 , certain amount of K phosphates and silicates eutectics were still formed, initiating and promoting sintering of ash from mixture of cornstalk and NH 4 H 2 PO 4 . Reactions between Ca(H 2 PO 4 ) 2 ·H 2 O and potassium salts under different conditions were also studied. It was found that reactions between Ca(H 2 PO 4 ) 2 ·H 2 O and potassium salts might already start as the temperature higher than 300 °C. K 2 CaP 2 O 7 , Ca 2 P 2 O 7 , Ca(PO 3 ) 2 and KCa(PO 3 ) 3 were identified as main products from these reactions and amounts of them considerably depends on the heat treatment temperatures and mixing ratios between Ca(H 2 PO 4 ) 2 ·H 2 O and potassium salts. Compared to KCl, K 2 CO 3 had a higher reactivity toward the Ca(H 2 PO 4 ) 2 ·H 2 O under same study conditions. The current work shows the addition of Ca(H 2 PO 4 ) 2 ·H 2 O is a promising approach to alleviate the ash sintering issues and assure efficient and smooth combustion of cornstalk.
研究领域:
能源与环境科学
·
生物质能研究
✓ 已验证
DOI
高影响因子
FIRE AND MATERIALS
·
2019
·Vol. 43
·期 8
·905-916
·
IF 1.173
Hangchen Li,Li Feng,Dexu Du,Xinxin Guo,Min Hua,Xuhai Pan
Summary To enhance the performance of existing dry powders and ensure process security, a new type of dry powder based on ammonium dihydrogen phosphate (NH 4 H 2 PO 4 ) was prepared. The prepared composite superfine dry powder was denoted as NH 4 H 2 PO 4 /zeolite composite in this paper. The effectiveness of commercial ABC dry powder, superfine dry powder, and the NH 4 H 2 PO 4 /zeolite composite in fire suppression were compared in a small-sized fire-extinguishing chamber. Laboratory-scale tests showed that the NH 4 H 2 PO 4 /zeolite composite had considerably superior fire-extinguishing efficiency to that of commercial ABC dry powder and superfine dry powder, along with shorter average extinguishing time and less average mass of powders consumed. In addition, the NH 4 H 2 PO 4 /zeolite composite also displayed much improved toxic gas suppression ability. The physical and chemical characteristics of commercial ABC dry powder, superfine dry powder, and the NH 4 H 2 PO 4 /zeolite composite were characterized using a range of techniques of laser particle size analysis, scanning electron microscopy, thermogravimetric analysis, and differential scanning calorimetry. Based on the analysis results, the improved fire suppression performance of the NH 4 H 2 PO 4 /zeolite composite can be ascribed to smaller particle size, larger surface area, and a special chemical decomposition process.
研究领域:
消防工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2024
·
IF 9.7
Ye Xiao,Xiaomin Zhu,Huihui Zheng,Qin Tang,Rongliang Qiu
Rice husk is a locally available biomass for preparation of adsorbents to deal with cadmium (Cd) contamination in paddy system. In this study, phosphorylation of rice husk using H 3 PO 4 and NH 4 H 2 PO 4 was carried out in the presence of urea at 165℃ to obtain APB-C and NPB-C, respectively. According to the material characterizations, phosphonyl groups were successfully grafted on the rice husk. Both APB-C and NPB-C had high performance for Cd(II) adsorption with the capacities of 146 and 129 mg/g, respectively. The main mechanism of Cd(II) adsorption was ion exchange with NH 4 + . The adsorption capacity was linearly corelated with phosphorus content (R 2 = 0.9997), while the Langmuir constant had high correlation efficient (R 2 = 0.996) with phosphonyl group percentage. Further quantum chemical calculation showed higher interaction energy between Cd(II) and phosphonyl group than other groups. These results indicated that phosphonyl group governed Cd(II) adsorption on phosphorylated biomass.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）