论文部分内容阅读
Soda residue dumps are a special type of urban industrial wasteland which causes serious damage to the environment,but little is known how to restore these wastelands in China and other countries.The main chemical constituents of soda residue are calcium chloride and calcium carbonate,which have serious negative effects on surface water and soil quality.In a solid form,the granules are very tiny with big interspaces and the residue turns to dust and is readily dispersed by the wind causing severe atmospheric pollution that is hard to manage.A soda residue dump located in Tanggu district in Tianjin was formed by producing alkali using the ammonia-alkali process over the last 80 years.In this project,more than 16,000,000m3 of soda residues were converted into an engineered soil that was mixed with fly ash calcium from 1996 to 2001.Seven hills were constructed with the engineered soil and converted into a reconstructed park named Ziyun Park.Peak height of the dump is 32 m.The surface of the hill-body was covered with 0.8-1.2 meters deep top soil and then planted.More than 40,000 flowers and plants,160,000 m2 of lawn and almost 300,000 arbors and shrubs with more than 100 plant species were cultivated in this project.After five-years,the ecological restoration has been successful.The experience gained from this project can offer guidance for other similar ecological restoration projects.