标题: seqjSU1tR73BoKd61y [打印本页] 作者: oquvq3520 时间: 2015-4-25 20:28 标题: seqjSU1tR73BoKd61y Fortunately, there is good news recently: Land and Resources, China Geological Survey Bureau, said the status quo will be fully consultation soil heavy metal pollution, soil heavy metals being drawn "map of human pollution." It is reported that China is building covers 81 chemical indicators (including 78 kinds of elements) geochemical reference network: 200 000 map sheets to the reference grid cells, each grid is laid sampling points, each point each Acquisition of a deep soil samples and soil samples a surface. Samples from 1 meter deep, were not representative of the nature of human pollution geochemical background; surface samples from shallow surface 25 cm, is a natural geological background superimposed pollution and human activities. Deep content by subtracting the surface content of heavy metals that come "Human pollution map." To repair a hundred years More bad news is that after the soil is contaminated we can not expect it to be like air and water self-repair. "In theory.
heavy metal contaminated soils can be repaired, but it is difficult to fully restore its ecological functions." Shi-Bao told reporters that at present the world of heavy metal contaminated soils for restoration measures proposed, there are many, including the two contaminated soil remediation Principle: containment (in-aiturem ediation) and removal (rem ove, ex-situ). Based on these two principles, remediation of contaminated soils are mainly isolated embedded, curing stability, the rule of separation of thermal and chemical stability, electrical repair, new soil and tilling the soil, leaching and soil bioremediation (including phytoremediation), but each measures there are some limitations apply. "Once heavy metals into the soil, and then be very difficult to repair, it takes a lot of time and money. For pollution characteristics of contaminated farmland (low level, a large area, the need to secure sustainable use, etc.), in situ chemical passivation (to reduce heavy metals soil - plant system migration into the core) technology because of its cost-effective.
fast repair time, easy operation and a wide range of advantages, more suitable for the repair of heavy metal pollution of farmland, with better environmental, economic and social benefits, and significant progress has been made. "Shi-Bao said. 70s over Japan Toyama soil remediation century, for example, a total of 863 hectares (12,945 acres) of farmland, invested $ 340 million in total, spent 33 years time off homemade repairs are completed, the average repair cost per acre of nearly 180,000 yuan. It is worth noting that Japan limits for cadmium rice is 0.4mg / kg.
while the limit value of cadmium rice only 0.2mg / kg, health risk control is to be strict in other developed countries. Strict limits cadmium in rice, which means that the soil quality standard cadmium correspondingly stringent. Shi-bao said Japan cadmium contaminated soil remediation cases, if the rice cadmium in accordance with our standards, then the repair cost and time will be greater,scarpe hogan donna, repair measures are more difficult. From the Chinese point of view of actual operation, contaminated site remediation funding sources can be divided into four categories: Lot's original owner, land acquisition side, the land of the repair side BT mode (Build and Transfer of abbreviations, which means "build - transfer" is a government uses non-government funding for a financing model based non-operating facilities construction projects) advances.
loans and related funds. Lixiang Ju stressed the need to strengthen the government's dominant soil remediation responsibility.