Frontiers of Environmental Science & Engineering
·
2020
·Vol. 14
·期 4
·1-12
·
IF 4.053
Zhu Meng,Luo Yongming,Yang Ruyi,Zhou Shoubiao,Zhang Juqin,Zhang Mengyun,Christie Peter,Rylott Elizabeth L.
Diphenylarsinic acid (DPAA) is a phenyl arsenic compound derived from chemical warfare weapons. Macroscopic and microscopic work on DPAA sorption will provide useful information in predicting the partitioning and mobility of DPAA in the soil-water environment. Here, batch experiments and extended X-ray absorption fine structure (EXAFS) spectroscopy were used to investigate the sorption mechanisms of DPAA. The DPAA sorption data from 11 soil types was found to fit the Freundlich equation, and the sorption capacity, K f , was significantly and positively correlated with oxalate-extractable Fe 2 O 3 . The K f values of eight of the 11 untreated soils (1.51–113.04) significantly decreased upon removal of amorphous metal (hydr)oxides (0.51–13.37). When both amorphous and crystalline metal (hydr)oxides were removed from the untreated soils, the K f values either decreased or slightly increased (0.65–3.09). Subsequent removal of soil organic matter from these amorphous and crystalline metal (hydr)oxide-depleted samples led to further decreases in K f to 0.02–1.38, with only one exception (Sulfic Aquic-Orthic Halosols). These findings strongly suggest that ligand exchange reactions with amorphous metal (hydr)oxides contribute most to DPAA sorption on soils. EXAFS data provide further evidence that DPAA primarily formed bidentate binuclear ( 2 C ) and monodentate mononuclear ( 1 V ) coring-sharing complexes with As-Fe distances of 3.34 and 3.66 Å, respectively, on Fe (hydr)oxides. Comparison of these results with earlier studies suggests that 2 C and 1 V complexes of DPAA may be favored under low and high surface coverages, respectively, with the formation of 1 V bonds possibly conserving the sorption sites or decreasing the steric hindrance derived from phenyl substituents.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2020
·Vol. 27
·期 14
·16646-16655
·
IF 3.056
Zhu Meng,Luo Yongming,Cheng Nannan,Yang Ruyi,Zhang Juqin,Zhang Mengyun,Christie Peter
Diphenylarsinic acid (DPAA) is an emerging phenylarsenic compound derived from chemical warfare agents. It has been suggested that biostimulation of sulfate reduction decreases the concentrations of DPAA in soils. However, biostimulation often induces Fe(III) reduction which may affect the mobility and thereby the transformation of DPAA. Here, a soil incubation experiment was carried out to elucidate the impact of Fe(III) reduction on the mobilization and transformation of DPAA in a biostimulated Acrisol with the addition of sulfate and lactate. DPAA was significantly mobilized and then thionated in the sulfide soil (amended with sulfate and sodium lactate) compared with the anoxic soil (without addition of sulfate or sodium lactate). At the start of the incubation period, 41.8% of the total DPAA in sulfide soil was mobilized, likely by the addition of sodium lactate, and DPAA was then almost completely released into the solution after 2 weeks of incubation, likely due to Fe(III) reduction. The relatively low fraction of oxalate-extractable Fe in Acrisol, which contributes significantly to DPAA sorption and is more active and reduction-susceptible, may explain the observation that only < 40% of the Fe(III) (hydr)oxides were reduced when DPAA was completely released into the solution. A more rapid and final enhanced elimination of DPAA was observed in sulfide soil and the fraction of total DPAA decreased to 60.1 and 91.0%, respectively, at the end of the incubation in sulfide soil and anoxic soil. The difference appears to result from increased DPAA mobilization and sulfate reduction in sulfide soil. On the other hand, the formation of FeS precipitate, a product of Fe and sulfate reduction, may reduce the efficiency of DPAA thionation. Accordingly, the potentially contrasting effects of Fe(III) reduction on DPAA thionation need be considered when planning biostimulated sulfate reduction strategies for DPAA-contaminated soils.
研究领域:
环境科学
·
土壤学
·
污染修复
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Meng Zhu,Yuan Li,Xiaobao Wei,Zhenqi Yan,Lu Yang,Ruyi Yang
Iron reduction impacts the mobilization and thionation of diphenylarsinic acid (DPAA) in soil, but the contribution of crystalline and non-crystalline iron remains unknown. A paddy soil deficient in non-crystalline iron (P-Fe o ), crystalline and non-crystalline iron (P-Fe d ) were incubated with sulfate-plus-lactate, and the results were compared with paddy soil (P) in our previous study. For treatments without ferrous sulfide (FeS) precipitation, the solution-to-solid ratio ( R L/S ) of DPAA increased slightly and dramatically with iron reduction, respectively, for P-Fe o and P, suggesting that the reduction of non-crystalline iron contributes more to DPAA mobilization than crystalline iron. The R L/S was > 0.667 and ≤ 0.667 for treatments without and with FeS, respectively, in P and P-Fe o but not P-Fe d , indicating that crystalline, rather than non-crystalline iron contributes more to DPAA sequestration through reduction and the subsequent FeS precipitation. The degree to which iron reduction facilitates DPAA mobilization or sequestration is likely determined by the composition and amount of iron in paddy soil, respectively. For treatments with FeS, the DPAA transformation rate was < 44 % and 74–86 %, respectively, in P-Fe o and P-Fe d after 90 days, with the maximum value comparable to those without FeS in P after 30 days. This suggests that the crystalline iron in P-Fe o and the residual, small amount of non-crystalline iron in P-Fe d could reduce DPAA thionation by forming FeS, and such effect seems to depend on both the composition and the amount of iron in paddy soil. The results would deepen our understanding of the “As-Fe-S” interactions in soil.
研究领域:
土壤科学
·
环境化学
✓ 已验证
DOI
PubMed
高影响因子
GEODERMA
·
2015
·
IF 2.772
Meng Zhu,Chen Tu,Haibo Zhang,Yongming Luo,Peter Christie
A solvent extraction method coupled to high-performance liquid chromatography with tandem mass spectrometry detection (HPLC–MS/MS) was developed and validated for the simultaneous determination of soil diphenylarsinic acid (DPAA) and phenylarsinic acid (PAA). Several extraction solvents were evaluated with respect to the degree of soil extract-induced matrix effects and the recovery values for DPAA and PAA in the four studied soil matrices. Validation data showed that solvent extraction had a negligible impact on the accurate quantification of DPAA. In contrast, only with disodium hydrogen phosphate extraction did the method give both limited matrix effects (102–107%) with a coefficient of variation < 3% ( n = 4) and efficient recoveries (77–109%) at two spiking levels (20 and 50 mg kg − 1 ) for PAA. The selection of an appropriate extractant was the approach to reduce matrix effects while guaranteeing satisfactory recoveries of soil DPAA and PAA. Chromatographic separation was completed in 37 min and the analytes were detected in positive mode using selected reaction monitoring . MS/MS operating conditions were optimized for both electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) sources. Under optimal conditions the detection limit was 0.01 and 1.00 μg L − 1 for DPAA and PAA. The method detection limits (MDLs) obtained ranged from 2.52 to 3.42 μg kg − 1 for DPAA and from 0.23 to 0.33 mg kg − 1 for PAA depending on the soil types, and the intraday and interday precision was less than 5% for both analytes at two different concentrations. The method was successfully applied for the simultaneous determination of DPAA and PAA in one-month aged soils, satisfactory recoveries (> 74.03%) were obtained for both analytes. The results show that the proposed solvent extraction method coupled to HPLC–MS/MS analysis can provide accurate and reliable determinations of DPAA and PAA in soil samples.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）