Impact assessment of odor nuisance, health risk and variation originating from the landfill surface.

Many researchers are concerned that municipal solid waste (MSW) threatens public health, causing them to increasingly focus on odor pollution. In this study, the odor nuisance and health risk impacts of landfill surface gas on eight sensitive receptors were assessed. The emission rates of odor and 145 volatile organic compounds (VOCs) were acquired by considering various landfilling operations, including high-density polyethylene (HDPE) membrane removal (MR), landfill tipping area (TA), temporary HDPE membrane cover (MC), top of the HDPE membrane (LM) and dumping platform (DP). Furthermore, differences in landfill surface geometry, such as emission height and source area, and variations in residential living floors were considered in odor assessment with the air dispersion model. Based on these uncertain factors, normal-, medial-, and worst-case scenarios were defined to elucidate the odor nuisance effect and health risk impact. Four of the eight sensitive receptors, which were 2.6 km away from the landfill surface, basically experienced odor nuisance and health risk impacts. Dichloromethane exerted an indelible and crucial impact on body health based on a comprehensive investigation of aromatics, halocarbons, and other chemicals. The odor nuisance and health risk impacts were notable near the landfill, and the local environment was remarkably damaged.

Correction to: The chemodiversity of paddy soil dissolved organic matter correlates with microbial community at continental scales.

An amendment to this paper has been published and can be accessed via the original article.

The chemodiversity of paddy soil dissolved organic matter correlates with microbial community at continental scales.

BACKGROUND: Paddy soil dissolved organic matter (DOM) represents a major hotspot for soil biogeochemistry, yet we know little about its chemodiversity let alone the microbial community that shapes it. Here, we leveraged ultrahigh-resolution mass spectrometry, amplicon, and metagenomic sequencing to characterize the molecular distribution of DOM and the taxonomic and functional microbial diversity in paddy soils across China. We hypothesized that variances in microbial community significantly associate with changes in soil DOM molecular composition. RESULTS: We report that both microbial and DOM profiles revealed geographic patterns that were associated with variation in mean monthly precipitation, mean annual temperature, and pH. DOM molecular diversity was significantly correlated with microbial taxonomic diversity. An increase in DOM molecules categorized as peptides, carbohydrates, and unsaturated aliphatics, and a decrease in those belonging to polyphenolics and polycyclic aromatics, significantly correlated with proportional changes in some of the microbial taxa, such as Syntrophobacterales, Thermoleophilia, Geobacter, Spirochaeta, Gaiella, and Defluviicoccus. DOM composition was also associated with the relative abundances of the microbial metabolic pathways, such as anaerobic carbon fixation, glycolysis, lignolysis, fermentation, and methanogenesis. CONCLUSIONS: Our study demonstrates the continental-scale distribution of DOM is significantly correlated with the taxonomic profile and metabolic potential of the rice paddy microbiome. Abiotic factors that have a distinct effect on community structure can also influence the chemodiversity of DOM and vice versa. Deciphering these associations and the underlying mechanisms can precipitate understanding of the complex ecology of paddy soils, as well as help assess the effects of human activities on biogeochemistry and greenhouse gas emissions in paddy soils.

[Effect of Simulated Climate Warming on Microbial Community and Phosphorus Forms in Wetland Soils].

Microbial community and phosphorus forms in response to simulated climate warming were studied by high-throughput sequencing and 31P nuclear magnetic resonance(31P-NMR) respectively, which were from wetland soils in constructed microcosm columns. The results revealed that relative abundances of Firmicutes, Clostridia, Clostridiales, Clostridiaceae and Clostridium were significantly decreased by 65%-98%, 69%-87%, 67%-87%, 73%-97% and 74%-93% under warming condition respectively, suggesting warming had a significant inhibitory effect on the bacterial lineage from Firmicutes to Clostridium at different taxonomic level. Particularly, principal coordinate analysis and cluster analysis also demonstrated warming had a significant effect on microbial community structure with obvious separation of samples between control and warmed groups from each wetland column site. Phosphorus forms were dominated by phosphomonoester and orthophosphate in each wetland column soil, which were significantly increased and decreased by 275% and 20% in XX wetland column soil respectively. Similarly, phosphomonoester and polyphosphate were also found to be increased and decreased by 85% and 49% in JH wetland column soil respectively, indicating that phosphorus forms in response to warming had soil heterogeneity. Canonical correspondence analysis showed that obvious changes in microbial community composition had significant effects on phosphorus forms under warming condition.