Widespread soil contamination is hazardous to agricultural products, posing harmful effects on human health through the food chain. In China, Cadmium (Cd) is the primary contaminant in soils and easily accumulates in rice, the main food for the Chinese population. Therefore, it is essential to derive soil criteria to safeguard rice products by assessing Cd intake risk through the soil–grain–human pathway. Based on a 2-year field investigation, a total of 328 soil–rice grain paired samples were collected in China, covering a wide variation in soil Cd concentrations and physicochemical properties. Two probabilistic methods used to derive soil criteria are soil–plant transfer models (SPT), with predictive intervals, and species sensitivity distribution (SSD), composed of soil type-specific bioconcentration factor (BCF, Cd concentration ratio in rice grain to soil). The soil criteria were back-calculated from the Chinese food quality standard. The results suggested that field data with a proper Cd concentration gradient could increase the model accuracy in the soil–plant transfer system. The derived soil criteria based on soil pH were 0.06–0.11, 0.33–0.59, and 1.51–2.82 mg kg⁻¹ for protecting 95%, 50% and 5% of the rice safety, respectively. The soil criteria with soil pH further validated the soil as being safe for rice grains.

Potato is globally recognized as the fourth most crucial staple food crop, trailing behind wheat, rice, and maize. Cadmium (Cd), a predominant heavy-metal pollutant in agricultural soils, demonstrates high biological toxicity and mobility. Therefore, exploring the genetic and molecular mechanisms underpinning cadmium tolerance in potato is of substantial theoretical and practical significance. In this research, an F₂ population composed of 170 families was established through the cross-breeding of homozygous diploid potato lines HD-5 (highly cadmium-tolerant) and M9 (cadmium-sensitive). Employing hydroponic cultivation, six traits, namely plant height (PH), root length (RL), shoot fresh weight (SFW), root fresh weight (RFW), chlorophyll content (SPAD), and nitrogen content (LNC), were measured in potato seedlings following a 9-day treatment with 40 mg·L⁻¹ CdCl₂. By utilizing the high-density genetic map of this population for QTL mapping, a total of 35 genetic loci associated with cadmium tolerance in potato seedlings were identified. Notably, loci21 and loci22 on chromosome 9, loci29 on chromosome 10, and loci31 and loci33 on chromosome 12 were consistently detected across multiple environmental conditions. This reproducibility across environments suggests the phenotypic stability of these five loci, which are thus considered reliable and robust genetic determinants. In addition, transcriptome sequencing analysis of roots from parental lines HD-5 and M9 after cadmium treatment revealed that significantly differentially expressed genes between the two parents were associated with glutathione metabolism and photosynthesis. By integrating QTL mapping, transcriptome analysis, and gene annotation, we screened four candidate genes involved in cadmium tolerance regulation: DM8C09G01000 (GST), DM8C09G01060 (GST), DM8C09G02130 (OXP1), and DM8C06G22960 (PsaH). These findings provide molecular targets and a genetic basis for molecular breeding of cadmium-tolerant potato varieties.

Nano zero-valent iron (nZVI) and its modified forms are promising for remediation of heavy metal-contaminated soils, but bare nZVI aggregates and oxidizes readily. In this study, carboxymethyl cellulose (CMC), polyvinylpyrrolidone (PVP), and sodium dodecyl sulfate (SDS) were used to prepare modified nZVI. The modifiers increased electrostatic repulsion and steric hindrance, inhibited aggregation, and maintained reactivity. The modified particles were smaller (5–15 nm vs. ~50 nm for nZVI) and more dispersible. In three heavy metal-contaminated soils from Zn–Pb mine areas in China, modified nZVI showed improved mobility and retention; column effluent Fe reached 595.5 mg/L for P-nZVI in S1 and 639.6 mg/L for C-nZVI in S3, although mobility varied with soil properties. After stabilization, TCLP leaching of Zn, Cr, Pb, and Cu decreased significantly. Zn leaching was reduced by up to 95.0% (P-nZVI, S3) and 93.49% (C-nZVI, S2); Cr leaching was reduced by up to 98.6% (S-nZVI, S3) and 97.0% (P-nZVI, S3); Pb and Cu reached below detection limits under optimized treatments (C-nZVI or P-nZVI at 1.0 g/L Fe) in selected soils. The K value, defined as (F1 + F2)/(F3 + F4 + F5), decreased by up to 16.25% for Zn, 11.88% for Cr, 13.63% for Cu, and 10.04% for Pb. Because K represents the ratio of labile to stable fractions, its decrease indicates a shift from labile to stable fractions, enhanced immobilization, and reduced bioavailability. Overall, PVP-modified nZVI performed best for Zn and Cr, whereas CMC-modified nZVI was most suitable for Pb and Cu.

Historical chemical production sites often harbor irregularly distributed solid waste landfills, posing significant environmental risks. Traditional drilling methods, while accurate, are inefficient for comprehensive characterization due to high costs and spatial limitations. This study aims to develop an integrated geophysical drilling approach to accurately delineate the spatial distribution and volume of landfilled solid waste (predominantly organic pollutants) at two decommissioned chemical plant sites (total area: 8954 m²). Methods: We combined (1) geophysical surveys (transient electromagnetic (TEM, 50 profiles, 2936 points), high-density resistivity (HDR, 2 profiles, 192 points), and ground-penetrating radar (GPR, 22 profiles, 1072.1 m)) and (2) systematic drilling verification (136 boreholes, ≤10 m × 10 m density). Anomalies were interpreted through integrating geophysical responses, historical records, and borehole validation. Spatial modeling was conducted using Kriging interpolation in EVS software. The results show that (1) the anomalies exhibited a “sparse multi-point distribution” across zones A2 (primary waste concentration), A4, and A6, which were differentiated into solid waste, foundations, contaminated soil, voids, and cracks; (2) drilling confirmed solid waste at nine locations (A2: “multi-point, small-quantity” residues; A6: contaminated clay layers with garbage) with irregular thicknesses (0.2–1.3 m); (3) TEM identified diagnostic medium–high-resistivity anomalies (e.g., 28–37 m in A4L3), while GPR detected 17 shallow anomalies (only one validated as waste); and (4) the total waste volume was quantified as 266.9 m³. The methodology reduced the field effort by ∼35% versus drilling-only approaches, resolved geophysical limitations (e.g., HDR’s volume effect overestimating the thickness), and provided a validated framework for efficient characterization of complex historical landfills.

Through sampling and analysis of 20 groundwater monitoring wells from nine oil storage enterprises in the Jiangbei New District of Nanjing, the pollution characteristics and chemical spatial distribution of total petroleum hydrocarbons (TPH) in the groundwater of the study area were revealed. TPH was detected in all 20 groundwater samples, with concentrations ranging from 0.26 to 90.24 mg/L. A factor analysis identified two principal factors, F1 and F2, representing the biodegradation processes of iron–manganese reduction and sulfate reduction, respectively. A correlation analysis showed that TPH was significantly positively correlated with total dissolved solids (TDS), total hardness, Fe, Mn²⁺, and oxygen consumption, but its correlation with sulfides and SO₄²⁻ was not significant. A further multiple regression analysis indicated that the relative contribution rates of electron acceptors followed the order of iron reduction (90.62%) > manganese reduction (9.35%) > sulfate reduction (0.032%), suggesting that TPH biodegradation is primarily dominated by iron–manganese reduction. Additionally, the study found that microbial growth was more robust in freshwater environments, facilitating TPH degradation, whereas saline environments inhibited microbial activity, thereby hindering TPH degradation.