| The Dabaoshan mine area is a very typical polymetallic sulfur mine,a large amount of sulphides are exposed to air oxidation when the mining resources are mined and smelted,resulting in serious acidification of the soil.Although aluminum toxicity caused by natural soil acidification is more studied,the characteristics of aluminum activation after acidification of the abandoned soil in the mining area are not clear.Aluminum toxicity is the main limiting factor for vegetation recovery and is an urgent problem to be solved in the vegetation restoration of the Dabaoshan mining area.In order to study the characteristics of aluminum activation in the Dabaoshan mining area and its inhibitory effect on the pioneer plants of Burma Reed?Neyraudia reynaudiana?,the basic physicochemical properties of the15 acidic spoil soils in the Dabaoshan mining area and 15 natural soils in the Guangdong Province were analyzed,and the morphology and effects of the soil aluminum were analyzed.By factor analysis,a four-factor,five-level,quadratic general combination design was used to study the synergistic relationship between aluminum and heavy metals on Neyraudia reynaudiana,which is soil and water conservation of the pioneer plant species,including the number of tillers,photosynthetic indicators,and the copper,zinc,calcium,and magnesium content in the leaves.Mathematical model between four factors:aluminum,copper,cadmium,and zinc.At the same time,the effect of the improver on the availability of aluminum and heavy metals in Dabaoshan acidic waste soil was studied by using lime and biomass ash.The results show:?1?The acid soil in the dump soil of the Dabaoshan mining area is dominated by sand and silt,and the pH value is generally low.The soil acidification is serious and the organic matter content is low.The extractable aluminum in the acidic waste of the Dabaoshan mining area mainly consists of exchanged,amorphous silicate aluminum and crystalline aluminum,with low content of organic bonded aluminum.The aluminum in the acidic waste of the Dabaoshan mining area mainly consists of exchanged,amorphous silicate aluminum and crystalline aluminum,with low content of organic bonded aluminum.In the Dabaoshan mining area,the acidic and water-extractable aluminum contents of the acidic soil were significantly higher than those of the natural soil.The maximum concentration of the centrifugal aluminum in Dabaoshan reached 2068.26 mg·L-1,but the highest in natural soil was only 34.42 mg·L-1.The maximum concentration of aluminum in the water extracted from Dabaoshan reached 188.35 mg·L-1,and the maximum concentration of aluminum in the water extracted from Dabaoshan reached 188.35 mg·L-1,whereas the highest concentration of aluminum in natural water was only 4.68 mg·L-1.The soil properties affecting the distribution of aluminum forms in the dump soil of the Dabaoshan mining area include pH value,organic matter content,cation exchange capacity,mechanical composition,total nitrogen,total phosphorus,total potassium,available phosphorus,and available potassium.Water-extracted and exchangeable aluminum are most susceptible to pH,organic matter,total nitrogen,and available potassium.In addition to the influence of pH,strong organic bonded aluminum also has a significant positive correlation with soil total nitrogen,available phosphorus,and available potassium.?2?According to the regression model established,when aluminum,copper,cadmium,and zinc are co-stressed,aluminum,copper,cadmium,and zinc all have a toxic effect on the reeds.Aluminum is the main influencing factor of tillering and photosynthesis to Neyraudia reynaudiana.The concentration of aluminum was 1500?mol·L-1 when it began to inhibit reeds.;Copper and cadmium are the main factors limiting the growth of roots;Zinc is the main factor that inhibits tillering.When aluminum interacts with zinc and copper,it inhibits the enrichment of copper and cadmium in the reed leaves,and the interaction between aluminum and cadmium and copper and zinc inhibits the enrichment of zinc in leaves.?3?Lime and biomass ash alone can effectively increase the pH of Dabaoshan's acidic soil and reduce the soil conductivity,thus reducing the effectiveness of aluminum and heavy metals in the soil.Low-level lime combined with biomass ash can effectively reduce the concentration of active aluminum.When the improved soil pH increased to 4.77,that is,lime10 g·kg-1 and biomass ash 40 g·kg-1,the concentration of aluminum in the as-spun and water-extracted forms decreased to almost zero.The zinc,cadmium content is also greatly reduced.The application of lime and biomass ash had no significant effect on the magnesium content in the soil. |
PDF Full Text Request