Soil Bacterial Community Structure and Diversity Variations at a Typical Hazardous Waste Illegal Dumping Site

Illegal dumping of hazardous waste is a major driver of environmental degradation, yet its site-specific associations with soil bacterial communities remain insufficiently understood. This study employed 16S rRNA gene high-throughput sequencing to investigate soil bacterial diversity and community composition and to examine their associations with measured environmental variables at a dumping site contaminated with nickel-bearing waste. The results showed lower soil pH and higher concentrations of nickel (Ni), chromium (Cr), and manganese (Mn) in the solid waste dumping area (SW) than in the control area (CK). The SW soils exhibited lower mean bacterial alpha diversity than the CK soils. This pattern was accompanied by variations in bacterial community composition between the two areas (p < 0.01). At the phylum and genus levels, the relative abundances of Acidobacteriota, Acidothermus, and Actinospica were significantly higher in the SW soils than in the CK soils. Correlation analyses indicated that variations in bacterial community composition were associated with pH, Ni, and Mn. These findings provide preliminary, site-specific evidence that bacterial community profiling may offer complementary biological information for characterizing ecological changes at the investigated site and warrant further investigation in the context of identification and assessment of environmental damage (IAED).