A Research Of The Agricultural Technology On Surplus Mud Of Urban Sewage Of Treatment Plant

The urban sewage disposal in our country discharges about 300,000 tons of dry mud every year. The mud has the characteristics of large containing capacity, instability, easy corruption and stench, etc. If the mud weren't utilized and handled wantonly, it would cause the serious secondary pollution. On the other hand, the mud contains a large amount of organic matter, many kinds of nutrition elements and trace elements that are helpful to the crops, so it is a kind of effective biological energy. Therefore, the combination of disposal and use of the mud is being paid more and more attention, because it will become the substituting resources that can turn waste into wealth. China is a large agricultural country, and it is a kind of treatment that is suitable for Chinese national conditions to make mud agricultural. This research just studies the dehydrated mud of Jinan Second Plant of Water Quality Purifying, carrying a feasibility analysis to the urban mud agriculturally, testing on the compost of the dehydrated mud and studying the craft and perimeters. These are the following results:1. Analyze regularly about the mud composition of Jinan Second Plant of Water Quality Purifying, there contain higher organic matter, nitrogen, phosphorus, potassium, and lower heavy mental. It totally accords with the national relevant standards of agricultural mud. Therefore, it is feasible to make the mud agricultural ofJinan Second Plant of Water Quality Purifying.2.According to the mud composition of Jinan Second Plant of Water Quality Purifying, make sure to put into the rice husk which contains carbon and silicon that can absorb the heavy metal and improve the quality of the soil, and the grass charcoal that contains nutrition elements, such as organic matter, humic acid and nitrogen, phosphorus, potassium, and the gray coal of powder that contains the trace element which plants need and has passivation function on the heavy metal. According to C/N=25, these four elements can be made up into 7 kinds of prescription. Therefore, it not only gets up to various kinds of elements to the consonance of the physiological function of the plant and good result produced after the chemical reaction, but also develops the utilization of the rice husk and gray coal of powder.3. Have a compost test on the 7 kinds of prescription, passing the evaluation index of physics and plant experimental analysis, and selecting the prescription II & V to be studied: Prescription II: mud + rice husk + grass charcoal + gray coal of powder (FA25), Prescription V: mud + rice husk + grass charcoal + gray coal of powder (PT35 + FA25). The period should be restricted in 35-48 days, and on the 35th day the germination percentage of Prescription II & Vis 85.6% and 85.6% respectively and germination index is 46.8% and 51.4% respectively.4. Have a situation analysis on the change of the content of heavy mental and the degree of thorough decomposition: Prescription V is better than Prescription II, so Prescription V [mud + rice husk + grass charcoal + gray coal of powder (PT35 + FA25)] is the best prescription;according to C/N = 25, the mixing percentage should be, mud : rice husk : grass charcoal: gray coal of powder = 4.3:1:2.5:2.25. The results of the experiment show: Prescription V contains rich nutrition composition, after 49 days of compost according to this prescription, the situation of nutritious contents are: organic matter 16.6%, total Nitrogen 12g/kr, total Phosphorus 4.7g/kg, total Potassium 3.4g/kg, quick -acting Nitrogen 2.8g/kg, quick-acting Phosphorus 0.3g/kg, quick-acting Potassium 1.2g/kg. The nutritious contents can beused directly by the plant and increase the output of crops. At the same time, it improves the nutrient state of the soil, soil structure and the fertile supporting ability of the soil. The research opens up a new way for mud recycle treatment - making mud agricultural.