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Research On The Use Of Waste Textiles For Soil Salinization Control

Posted on:2022-06-01Degree:MasterType:Thesis
Country:ChinaCandidate:D WangFull Text:PDF
GTID:2510306494494654Subject:Environmental Engineering
Abstract/Summary:PDF Full Text Request
Soil salinization is one of the main types of land degradation.China's saline-alkali land area ranks the fourth in the world.Saline-alkali soil changes the physical and chemical properties of the soil and limits the range of soil use.Preventing soil salinization by scientific means can delay the increase of salinization land area,and the restoration of existing salinization land can alleviate the shortage of global land resources and solve the problem of food security.In this study,waste textile recycled materials were used to construct soil capillary barrier layer to regulate the migration direction of salt water in the soil to prevent soil salinization and avoid the secondary harm of salt and alkali in the restored soil.The specific research contents of this study are as follows:In this experiment,recycled polypropylene material and recycled polyester material were laid below the soil root growth zone as soil capillary barrier to prevent soil salinization by blocking the way of soil water and salt migration,and the influence of different materials on water and salt migration was analyzed.The results showed that the soil water content in the rhizophytic zone of the experimental group was stable below 10% and the soil salt content was stable at about 0.5ms/cm.The long-term observation of the polypropylene nonwoven group showed that the soil salt content in the rhizophytic zone was maintained at a low level for a long time.However,the salt content in the upper soil of the experimental group and the control group with large pore diameter polypropylene sheet increased gradually with the increase of soaking days,indicating that the experimental material can effectively block the migration of soil water and salt,and avoid the salinization of the soil layer in the root zone(0-30 cm depth).The results showed that laying recycled materials with pore diameter less than110 um below the root zone(0-30cm)could block the movement of soil water and salt and avoid the occurrence of soil salinization in the root zone.Water irrigation can form soil layer with lower salt content in soil root growth zone.Under the action of soil capillary,the cessation of irrigation will lead to the accumulation of salt in soil again to the root zone of soil,forming saline-alkali soil and causing harm.In this study,waste recycled materials were laid below the soil root growth zone to regulate the transport direction of soil water and salt to avoid the secondary harm of salt and alkali in the soil after restoration.In addition,materials with different physical and chemical properties were compared to analyze the influence of irrigation amount,materials and other factors on the improvement of soil physical and chemical properties,and the improvement measures to increase water flux were proposed.The research results showed that after 21mm/48h-20 irrigation,the soil residual amount in the soil column root growth zone with polyester nonwoven fabric as the barrier material was 2.76ms/cm,and the electrical conductivity of the underlying soil was increased by about 8 times.Moreover,polyester nonwoven fabric could block the upstream flow of soil water,so the soil was avoided from secondary damage.Due to its physical and chemical properties,the recycled polypropylene non-woven cloth completely blocks the transport of water and salt,which can be used for soil moisture conservation and soil remediation,reducing the loss of soil moisture and avoiding soil pollution.In conclusion,recycled polyester/polypropylene nonwoven fabric can play a better role in the remediation of saline-alkali soil and the prevention of saline-alkali soil.The physical and chemical properties of various recycled materials determine the different ways of use.
Keywords/Search Tags:soil salinization, Migration of soil water and salt, Soil capillary barrier, Saline-alkali soil restoration, Prevention of saline-alkali soil, Regenerated chemical fibre
PDF Full Text Request
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