Characterization of phosphorus in the sedimentary environments of inundated agricultural soils around the Huainan Coal Mines, Anhui, China

• Published in: The Science of the total environment Vol. 472; pp. 538 - 549
• Main Authors: Yi, Qitao, Xie, Kai, Sun, Pengfei, Kim, Youngchul
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.02.2014; Elsevier
• Subjects: Agricultural soils; Agriculture; Applied sciences; Biological and physicochemical phenomena; Biological and physicochemical properties of pollutants. Interaction in the soil; China; Coal Mining; Environmental Monitoring; Eutrophication; Exact sciences and technology; Geologic Sediments - chemistry; Inundation; Iron; Lakes - chemistry; Natural water pollution; Phosphorus; Phosphorus - analysis; Pollution; Soil; Soil and sediments pollution; Water Pollutants, Chemical - analysis; Water treatment and pollution; Asia; China; China, People's Rep; Phosphorus; Iron; Agricultural soils; Inundation; Eutrophication; Laboratory study; Organic matter; Soil column; Transition metal; Agricultural soil; Nitrogen; Soil pollution; Sediments; Heavy metal; Characterization; Trace element; Iron Oxides; Flood; Coal mine; Environment; Water pollution; Ecological recovery; Rehabilitation; Dissolved inorganic carbon
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2013.11.060

Extensive coal mining in the Huainan Coal Mines, Anhui China, in light of the local hydrology and geology, has resulted in extensive land subsidence and submergence around the mines. This has led to the formation of large (>100km2) lakes. Three representative lakes were selected to study the mechanisms of phosphorus (P) unavailability for primary production from the perspective of sedimentary environments, which in turn owe their formation to permanently inundated agricultural soils. Two important issues were considered: (1) potential of P transport from the cultivated soil column toward surface sediments and (2) characterization of P behavior in view of regional ecological rehabilitation and conservation. Accordingly, we conducted field sediment analyses, combined with simulation experiments of soil column inundation/submergence lasting for four months. Enrichment of Fe-(hydr)oxides in surface sediments was verified to be the main reason for limitations in regional P availability in water bodies. Iron (Fe), but not its bound P, moved upward from the submerged soil column to the surface. However, an increasing upward gradient in the contents of organic matter (OM), total nitrogen (N), total phosphorus (TP), and different P fractions was caused by spatial heterogeneity in soil properties. Phosphorus was unable to migrate upward toward the surface sediments as envisioned, because of complex secondary reactions within soil minerals. Phosphorus bound to Fe and/or Al comprised over 50% of TP, which has important implications for local ecological rehabilitation and water conservation. •Coal mining activities underground have led to the formation of unique aquatic zones.•Potential of P contribution for inundated agricultural soils was characterized.•Fe, but not its bound P, moved upward from the inundated soil column to the surface.•Reactive Fe oxides in local submerged soils have great capacities for P adsorption.