Inorganic composite conditioner for effective sludge dehydrating

Abstract

The invention discloses an inorganic composite conditioner for effective sludge dehydrating, comprising an inorganic high valent cation coagulant, quicklime and inorganic powder fine aggregate, wherein the weight percentages are as follows: 2-10% of the inorganic high valent cation coagulant, 30-50% of quicklime and 40-67% of inorganic powder fine aggregate. The invention also discloses a use method for the inorganic composite conditioner. The conditioner disclosed by the invention can obviously lower specific resistance of sludge (SRF) and capillary suction time (CST) so as to large raise the sludge dehydrating performance. In addition, the drugs of the conditioner are cheap, and the organic contents of the sludge cake after dehydrating are low, and the inorganic material compositions in the conditioner are helpful for forming the strength during the subsequent preparation of backfilling mulching soil and building materials, and the sludge cake after dehydrating can be used as a raw material for preparing the backfilling mulching materials and the building materials.

Description

technical field [0001] The invention relates to sludge treatment technology, in particular to an inorganic composite conditioner for treating sludge with a moisture content as high as about 97%. Background technique [0002] Sludge with a moisture content of about 97% produced by urban sewage treatment plants is a hydrophilic organic aggregate with extracellular polymer (ECP) as the main body. It has branches and network structures similar to fluff in appearance. Regular, highly non-uniform, very high specific surface area and porosity (porosity is often greater than 99%); high organic content, easy to spoil and odor; finer particles, small specific gravity; high moisture content, not easy to dehydrate. The current dehydration technology generally uses polyacrylamide (PAM) flocculant conditioning and then mechanical dehydration, and only mud cakes with a moisture content of about 80% can be obtained. Thermal drying technologies with high energy consumption and high operatin...

AI Technical Summary

Problems solved by technology

When the treatment effect is good, the content of organic polymer dehydration conditioner is high, the cost is high, and it is difficult to reuse the dewatered cake

In CN1986788A, the sludge is tempered by adding water first, and then adding iron salt, calcium salt or calcium oxide step by step. Although the dehydration effect is still good, the dosage of calcium salt or calcium oxide is too large, and the mud cake is highly alkaline.

The sludge dewatering agent disclosed in CN101100345A is aimed at dewatered sludge with a water content of about 80%, and the surface active ion dispersant is as high as 5%, and the surfactant in the filtrate will inevitably increase, causing secondary pollution

The composition of composite filter aid in CN101182095A includes as many as 9 kinds, and the preparation process is complicated

The disadvantage is that the dosage is too large, which is 5-20% of the mass of the water-containing sludge, which will inevitably lead to a large increase in sludge volume.

CN101693593A The organic matter content of the mud cake produced by the conditioning method is about 10% higher than that of the mud cake with iron salt and calcium oxide as dehydrating agents, which is not conducive to subsequent disposal methods such as landfill

[0005] First, the dewatered sludge with a water content of 80% is used as the treatment object. Although it meets the actual operation needs of the current sewage treatment plant, in the long run, adding 60% to 70% of the water to the dewatered sludge is used for conditioning. The treatment process is complicated, wastes water resources, and is not conducive to energy saving and emission reduction;

[0006] Second, the conditioning agent has both organic and inorganic components, which increases the organic matter content of the mud cake, which is not conducive to being used as a landfill covering material or to prepare building materials;

[0007] Third, the dosage of the agent is too large, resulting in a large increase in the size of the mud cake