JPS59147700A - Treatment of sludge - Google Patents

Abstract

PURPOSE:To treat easily sludge at a low cost by adding and mixing a solidifying material consisting essentially of a hydraulic cement material with the sludge then dehydrating and incinerating the sludge. CONSTITUTION:A solidifying agent consisting essentially of a hydraulic cement material (normal Portland cement) and if necessary a flocculating agent (a high polymer flocculating agent consisting essentially of polyaminoalkyl acrylate) are added and mixed to and with hardly solidifiable sludge such as sewer sludge in treating said sludge. After the sludge is dehydrated, the dehydrated sludge is incinerated. Septic smell is thus suppressed and auxiliary fuel is reduced. Water is added to the incinerated sludge to soften the same by water and the softened sludge is made into a granular material usable as land reclamation material, road bedding material, etc.

Description

Detailed Description of the Invention The present invention mainly relates to sewage sludge generated at sewage treatment plants, sludge as muddy industrial waste generated from the treatment of factory wastewater, etc., and the bottom of rivers, lakes, ports, sea areas, etc. The present invention relates to a method for treating various kinds of sludge, such as accumulated sludge, which can cause environmental deterioration if left untreated, so that they can be reused as landfill material, roadbed material, etc.

The conventionally known sludge processing power method is that after adding and mixing various flocculants to sludge, (1)
There are three treatment methods: (2) a solidification treatment method in which all assimilates are added and mixed after dehydration treatment, and (3) an incineration treatment method in which incineration is performed after dehydration treatment. The incineration method described in [3] is rapidly increasing from the viewpoint of saving storage space for waste materials and facilitating the transportation of waste materials. However, this incineration treatment method generally has various drawbacks as described below. That is, (a) When storing and transporting the dehydrated cake, the putrid odor of the dehydrated cake causes significant odor pollution.

(b) Since the moisture content of the dehydrated cake is as high as 75 to 85 yen, handling during transportation is extremely difficult, and a large amount of auxiliary fuel is required during incineration.

3. Because the dehydrated cake has viscosity, it takes on the shape of a nodule, and during incineration, the hearth drop opening is likely to be clogged and unburned areas inside the nodule easily occur.As a countermeasure, the dehydrated cake is incinerated. It is necessary to blow hot air into the oil to preheat it and granulate it, which complicates the processing process.

) In order to prevent the elution of heavy metals in the incineration ash and to quickly stabilize the ground during reclamation, it is necessary to assimilate the ash using special cement when reusing it.

These problems result in complicated processing and high processing costs.

The present invention has been developed based on the above-mentioned circumstances, as well as making handling easier by lowering the water content of the dehydrated cake, suppressing putrid odor to an extremely small amount, reducing the amount of auxiliary fuel used during incineration, and improving the hearth drop opening. This provides a very advantageous treatment method from an economical and construction perspective by preventing blockages and the occurrence of unburnt spots, and in addition, by making it extremely easy to fix heavy metals in the soot ash when reusing treated materials. There is a purpose in what you do.

The sludge treatment method according to the present invention, which has been made to achieve the above object, is characterized by adding and mixing an assimilating agent whose main component is a hydraulic cement type substance to the sludge, dewatering the sludge after sludge, and then dewatering the sludge. Dehydrated sludge? It is at the point of being incinerated.

The effects of the present invention having such characteristics are as follows.

In other words, hydraulic cement-based materials added to and mixed with sludge that emit a strong odor usually cause agglomeration or coagulation of hydrophilic colloid particles suspended in the sludge because it usually contains a large amount of organic substances in the form of colloidal particles. The sludge adsorbs the particles and at the same time binds them together, gradually turning them into coarse particles.The sludge exhibits good water permeability and becomes sand-like with low water content through dehydration. The amount of fuel used can be suppressed to an extremely small amount, and preheating in the next process of incineration is no longer necessary, making it possible to significantly reduce the amount of fuel and simplify the process. Furthermore, it is worth noting that the hydraulic cement-based materials added and mixed prior to the dewatering process may be affected by the large amount of organic material present during dewatering or by the pore water containing a large amount of molten matter in the dehydrated cake. However, by incinerating this dehydrated cake, hydration inhibition due to combustion is removed, and hydrate activation is achieved. When reusing the incinerated material, it becomes hydraulically hardened by simply adding and mixing special cement, and the heavy metals are insolubilized by the heavy metal wicking function. Etc. ground level
Stabilization can also be promoted, and we have now provided a processing method that is very advantageous in terms of economy and construction compared to conventional methods.

Next, an uninvented embodiment will be described.

Sewage sludge generated at sewage treatment plants, sludge as muddy industrial waste generated from the treatment of factory wastewater, rivers, etc.
The bottom sediment of lakes, ports, sea areas, etc., as well as various sludge such as accumulated sludge, can be reused as fill material for landfills, roadbed materials, etc. In the treatment, an assimilating agent mainly composed of hydraulic cement-based substances and a flocculant are added and mixed into the sludge, followed by dewatering treatment, followed by incineration of the dehydrated sludge, and further, Water is added to the incinerated material to form aqueous solution, producing granular grains that can be used as landfill material, roadbed material, etc.

Next, an experimental example will be shown.

Add and mix 100% of the solidifying agent to the dry matter amount of 4 m of sewage sludge having the following properties, and after about 10 minutes, add 0.7% of the cationic flocculant i, and perform dewatering using a decanter. Okay, next, make the dehydrated cake all in a Matsufuru oven.
000'0 Incineration was performed for 1 hour.

Sludge: Sewage treatment plant thickened sludge moisture content 297.12. Ignition loss related to: 59.97% Heavy metal 2 T2 GF2000 ~ Gradient (drying equivalent) Separate water: Centrifugal water (model decanter m:]. (l vHr) Centripetal force, differential speed, liquid level difference, slurry supply system 3000 () X 10rpm X 5mm X
1. Om” / & Incineration: Muffle furnace 1000° 01 hour 61 Environment Agency Notification 13-5J (3rd day of Zaisei Ma) Me2 Determined from the installation and maintenance aspect of incinerator @ τTg As a self-hydrous cement-based material For example, various Portland cements, blast furnace cements, fly ash cements, solid cements, pozzolan cements, high alumina cements, high alumina high sulfate cements, etc. can be used alone or in mixtures. ,
For example, calcareous additives such as slaked lime and quicklime may be mixed in to adjust the assimilation material.

In addition, the if'jf A specific agent is not necessarily necessary for carrying out the present invention, but when using it, water-soluble cationic flocculant and anionic flocculant AII are recommended. - They may be used simultaneously or separately, and other surfactants may be mixed into the kneading if necessary to form agglomeration h;j.

Especially, when dewatering sludge according to the method V of the present invention, various forced dehydration means and devices such as centrifugal dehydration, vacuum dehydration, filter press dehydration, belt press dehydration, pressure dehydration, etc. can be used. Needless to say).

In addition, when incinerating the dehydrated cake by the method of the present invention, it is possible to use various types of equipment, such as a vertical multistage furnace, fluidized combustion furnace, rotary drying incinerator, etc. j,'i Umaena 00 Agent Patent Attorney
Osamu Kitamura Continued from page 1 0 Inventor: Hiromizu Tajiri, Takenaka Corporation Osaka Main Store, 4-27 Honmachi, Higashi-ku, Osaka Inventor: Yutaka Sakaguchi, 4-27 Honmachi, Higashi-ku, Osaka Inventor: Toru Hongo Inside Takenaka Corporation Osaka Main Office, 4-27 Honmachi, Higashi-ku, Osaka City

Claims (1)

[Claims] ■ A method for treating sludge, which comprises adding and mixing an assimilating agent whose main component is a hydraulic cement-based substance into sludge, followed by dewatering the sludge, and then incinerating the dehydrated sludge. (2) The method for treating sludge according to claim 0, characterized in that a flocculant is used simultaneously with or separately from the solidifying agent. (2) The sludge treatment method according to claim 0, characterized in that the sludge is hard-to-solidify sludge such as sewage sludge. (2) The sludge treatment method according to claim 0, wherein ordinary Portland cement is used as the hydraulic cement-based material. (2) The sludge treatment method according to claim 0, wherein a polymer flocculant containing polyaminoalkyl acrylate as a main component is used as the flocculant.