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The study aimed to synthesize novel zeolite substrates modified with four types of ZnAl-LDHs including Cl-LDHs(1:1), Cl-LDHs(3:1), CO3-LDHs(1:1), and CO3-LDHs(3:1); investigate Cr(VI) removal efficiencies in lab-scale constructed wetlands (CWs); and explore the effect of different Zn/Al ratios and intercalated anions on the removal efficiencies of Cr(VI) by modified zeolite. Different ZnAl-LDHs were prepared by co-precipitation method and coated onto the surface of original zeolite. Field emission scanning electron microscope and energy dispersive spectrometer were used to analyze physicochemical properties of zeolite/ZnAl-LDHs. Obtained results confirmed the successful LDHs-coating modification. The results of both X-ray diffraction and Fourier transform infrared suggested that the typical diffraction peak and functional groups of ZnAl-LDHs were detected in modified zeolites, and the peak of CO32− in CO3-LDHs at 1362 cm−1 was stronger and sharper than Cl-LDHs. It could be demonstrated by above results that the synthesis crystallinity and coating effect of CO3-LDHs was better than Cl-LDHs. Furthermore, it could be found that under the condition of same intercalated anion, LDHs with metal molar ratio of 1:1 had better crystallinity than LDHs with metal molar ratio of 3: 1. Subsequent determination of the removal performance of Cr(VI) by purification experiments revealed that zeolite/Cl-LDHs(3:1) showed the best Cr(VI) removal performance, and the removal rate of Cr(VI) was improved by 32.81% compared with the original zeolite, which suggested that could be an efficient substrate of CWs for Cr(VI) removal. The high crystallinity indicated that the structure of LDHs was stable and it was difficult to remove Cr(VI) by ion exchange. The above explained why the Cr(VI) removal efficiency by zeolite/Cl-LDHs is superior to that by zeolite/CO3-LDHs under the condition of same metal molar ratio. With the increase of metal molar ratio, the charge density of LDHs layers and intercalated anion increased, thus enhancing the electrostatic attraction of LDHs layers to Cr(VI) and the interlayer anion exchange capacity. However, the effect of charge density on Cr(VI) removal efficiency may be greater than crystallinity on removal efficiency, which could be responsible for the fact that zeolite/ZnAl-LDHs(3:1) had better Cr(VI) removal efficiency than zeolite/ZnAl-LDHs(1:1) under the condition of same intercalated anion. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) contamination in edible agricultural products, especially in crops, has raised worldwide concerns regarding food safety consumption. This review summarizes the current knowledge of the applicable methods and perspectives for reducing Cd contamination of agricultural products. Agricultural approaches of soil amendments, irrigation management, microbial agent, and cropping patterns were systematically concluded to illustrate the developments and achievements in crop contamination management. The use of traditional soil amendments as well as novel nano-materials has contributed to producing safe crops in agricultural soil contaminated with Cd. This review provides an inspiring and promising tool for maintaining food safety by reducing Cd accumulation in edible agricultural products. [ABSTRACT FROM AUTHOR]

To investigate the molecular mechanism of Cd-accumulating difference between Lactuca sativa cultivars, full-length transcriptome comparison, as well as biochemical validation, have been conducted between Cd pollution-safe cultivar (Cd-PSC, cv. LYDL) and high-Cd-accumulating cultivar (cv. HXDWQ). The full-length transcriptome of L. sativa cultivars was achieved for the first time. The results showed high Cd compartmentalization in the cell wall of cv. LYDL was ascribed to the enhanced cell wall biosynthesis under Cd stress, which was consistent with the high cellular debris Cd level (32.10–43.58%). The expression levels of transporter genes in cv. HXDWQ were about 1.19 to 1.21-fold higher than those in cv. LYDL, which was in accordance with the high ratio of easy migrative Cd chemical forms (68.59–81.98%), indicating the high Cd accumulation in the shoot of cv. HXDWQ was ascribed to the higher transportation capacity in cv. HXDWQ. Moreover, the Cd-induced endoplasmic reticulum (ER) stress was associated with the higher Cd detoxification and tolerance in cv. HXDWQ rather than in cv. LYDL. The study provides new insights into the Cd-induced transcriptomic difference between L. sativa cultivars and further contributes to the molecular breeding of L. sativa Cd-PSC. [ABSTRACT FROM AUTHOR]

Triphenyl phosphate (TPhP) is one of the novel alternative retardants with increasing utility. As a potential obesogen, the direct disruption of TPhP on lipid metabolism in hepatocyte has been widely studied. However, the microRNAs (miRNAs) regulation patterns of lipid metabolism disruption effects in hepatocyte under TPhP exposure remain unknown. This study aimed to elucidate the adverse effect of TPhP on hepatocyte through cell viability, TPhP clearance, and epigenetic miRNA alterations of hepatocytes at short (3 h) and long term (48 h) exposures to TPhP. The cell viability of hepatocyte raised at the low TPhP concentration treatments but dramatically decreased after the 10 µg⋅mL-1 TPhP treatment, and concentration for 50% of maximal inhibitory effect was 46.7 µmol⋅L-1 . The clearance rates of TPhP in hepatocyte were 73.9% and 85.1% after 3 h and 48 h incubations, respectively. Plenty of miRNAs were differentially expressed under TPhP treatments of 5 µg⋅mL-1. The predicted target genes of these differential expressed miRNAs were mainly involved in metabolic, fatty acid biosynthesis, steroid biosynthesis and cancer related pathways. The regulation network of miRNA-mRNA was constructed according to the correlations between miR-34c-5p, miR-301a-5p, and miR-7 and lipid metabolism related genes. Lipid metabolism disruption by TPhP was achieved by a proposed integration network of differential expressed mRNAs and miRNAs. Our study provides important insight in potential miRNAs biomarkers such as miR-4484 and miR-7 and the miRNA-mediated lipid metabolism disruption effect on human hepatocytes under TPhP treatment. [ABSTRACT FROM AUTHOR]