| In the process of mining and utilization of coal mines in Xinjiang's arid region,coal gangue,burning stone,coal ash,production and living sludge and other large quantities of wastes produced by coal power stations and sewage treatment stations of related facilities in the mining area not only occupy land,cause environmental pollution,but also cause resource waste.Hami Dananhu No.2 Mine in the test area is located in the desert Gobi,and the original ecological environment is very bad:extreme drought;Extremely high temperature in summer,the temperature difference between day and night is large;The soil is poor and salinized seriously;Sandstorms are frequent.Plants are difficult to survive,causing huge obstacles to the restoration of ecological environment.From 2018 to 2020,fly ash,burning stone and domestic sludge was used as experimental materials,and soil formulation was set in combination with desert soil in mining areas,so as to build a better microenvironment than the original ecology for plant growth,and provide theoretical basis and technical support for ecological restoration of coal mines in arid areas.(1)The pH value of 0-30 cm soil in the mining area is 8.62,and the salinization type is chloride-sulfate type.The soil type is mainly gypsum salt pan brown desert soil.The total nitrogen content was 0.12 g·kg-1,total phosphorus content was 0.20 g·kg-1,and total potassium content was2.68 g·kg-1,all of which were extremely deficient.The available potassium reached a high level of1050.12 g·kg-1.(2)The pH value of fly ash is 9.63,and the particle size of fly ash is mainly coarse powder,accounting for 45.19%.Total nitrogen content was 0.061 g·kg-1;The total phosphorus content was0.616 g·kg-1.The total potassium content was 0.888 g·kg-1.(3)The treatment of"desert soil+10%fly ash+stone over"has built a better microenvironment for plant growth than its original ecology,which is an effective way to preserve water and promote seedling soil.The addition of fly ash in desert soil can reduce the soil hardness,and the soil surface covered with burning stone can significantly reduce the soil water loss rate.Sorghum sudanense(Piper)Stapf.was planted in the plot experiment.The"desert soil+10%fly ash+stone over"plot was composed of stone crevasses to form the microenvironment for the growth of Sudan grass.1 to 4d after irrigation,the soil moisture content increased by 5.93-10.84%compared with CK.At 15:30,the surface temperature was significantly lower than the bare land temperature,and the temperature difference between day and night was small.The plant height,aboveground and underground biomass of Sudan grass were 1.9 times,5.9 times and 2.7 times of that of CK,respectively.(4)The application of fly ash and domestic sludge in desert soil had extremely significant effects on soil TN and TP adsorption(P<0.01).Through pot experiment to plant alfalfa,"desert soil+10%fly ash+1%sludge"combined application has the best effect.(5)Using coal ash,burning stone and yellow clay as materials,a landscape tree planting method was established."U"-shaped yellow clay layer and overburden stone treatment can significantly increase soil moisture content.In June and October,1 to 5d after irrigation,the soil water content in the pit of the treated plot was significantly higher than that of CK(P<0.05).Wind shield and other measures have reduced the temperature difference between day and night.In June,at 6:30 AM on the 1st to 5th day after irrigation,the surface temperature of the treated plot was higher than that of CK by 3-8?,while at 15:30 PM,it was significantly lower than that of CK by2-12?.Six months after planting,stem diameter increment,branch increment and leaf number of Ulmus pumila L.in the treatment community were higher than those in CK group. |
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