Reading guidance：Urban sludge because it contains heavy metals, bacteria and pathogenic microorganisms, organic matter, such as, direct access to the environment will be caused by environmental pollution events. After

    Urban sludge because it contains heavy metals, bacteria and pathogenic microorganisms, organic matter, such as, direct access to the environment will be caused by environmental pollution events. After effective treatment of municipal sewage sludge for agricultural use must also follow certain standards, in order to ensure sludge use in agriculture, the pollution of the environment pollution minimum risk. Among them, the research in this area in western developed countries and use to priority in China, therefore, to understand the west of sludge in agricultural use of standard of our country agriculture using standard construction has certain influence, from which they can draw the valuable experience and give up which is not suitable for the situation of our country's terms, through this, the sludge treatment disposal industry development.
    The history of city land utilization of sewage sludge is longer, the city in 1983 for sludge disposal and utilization regulation of.1993 in February. The city ordinance amendment again revised sludge land, according to the level and ecological risk assessment of city sludge heavy metal concentration will result in city sludge is divided into two types: one is the so-called clean city sludge or "quality" city sludge, another is to meet the city sludge heavy metal concentration control standard. The city sludge can meet the quality requirements, as long as the application of heavy metals into the city sludge does not exceed the annual limit, can be applied directly on the land. If the heavy metal content is higher than the quality of city sludge, but do not exceed the maximum concentration control criteria can also be used in the land, but also must meet 2 conditions: one is the total amount of heavy metals entering the land does not exceed the limit standard Two years into the quasi; heavy metal pollutants amount can not exceed the per unit land area control standards. In addition, the revised standards according to the city sludge pathogen content will be divided into a and B city sludge class 2, class a refers to the fecal coliform below 100 pg (dry weight) of city sludge, B refers to the class fecal coliform is less than 2 * 106 PG (dry weight) of the city. A city sewage sludge sludge can be applied in the food chain of crop land cultivation, and the application of B class city sludge has many specific provisions. The city does not meet the highest concentration of heavy metal sludge control standards shall not be applied in the land, must be taken other measures such as incineration, landfill disposal. The EU has enacted in 1986 the city sludge heavy metal control standards, the maximum allowable amount of heavy metals in farmland soil heavy metals in sewage sludge in farmland and city in the largest amount, than its standard The United States is strict.
    Sewage sludge application to the problem of environmental pollution control, the basic way is to determine the environmental capacity. Soil of sewage sludge of the largest capacity is usually in order to control the municipal sewage sludge and soil heavy metal concentrations and accumulation to develop.
 

：Have a good understand to shape of heavy metals; Pay attention to the influence of agricultural utilization of sludge ：Current situation of sludge disposal