CN101948231A

CN101948231A - High-concentration anaerobic sludge digestion treatment process for carrying out mechanical dewatering on sludge

Info

Publication number: CN101948231A
Application number: CN2010105049976A
Authority: CN
Inventors: 李子富
Original assignee: University of Science and Technology Beijing USTB
Current assignee: Nanjing Riverside Resources And Ecology Research Institute Co Ltd
Priority date: 2010-10-14
Filing date: 2010-10-14
Publication date: 2011-01-19
Anticipated expiration: 2030-10-14
Also published as: CN101948231B; WO2012048504A1

Abstract

The invention relates to a high-concentration anaerobic sludge digestion treatment process for carrying out mechanical dewatering on sludge, comprising the following steps of: conveying sludge with high water content into a concentration tank, wherein the water content of the concentrated sludge is reduced to 97 percent, and a supernate reflexes to a sludge treatment system; carrying out mechanical pre-dewatering on the concentrated sludge, wherein the water content is about 88-90 percent after the mechanical pre-dewatering; then carrying out anaerobic digestion on the pre-dewatered sludge under the high concentration condition by adopting a CSTR (Continuous Stirred-Tank Reactor); and further dewatering the sludge after anaerobic digestion, wherein the water content of a treated sludge cake is about 75 percent. The invention has following advantages and positive effects: by adopting the technical scheme, the dewatering effect of the sludge is favorable, the volume of an anaerobic sludge digestion tank is greatly shortened, and the capital construction investment and the operation cost of a sewage treatment plant are reduced; the load of organic matters in the sludge can be effectively improved by carrying out pre-dewatering on the sludge; and the CSTR anaerobic sludge digestion which is suitable for the high-concentration solid materials is used for treatment, which is beneficial to sludge resource utilization.

Description

Mud is carried out the high concentration sludge Anaerobic Digestion technology of the pre-dehydration of machinery

Technical field

The invention belongs to technical field of sludge treatment, relate to a kind of dewatering technology of mud that before the sludge digestion unit, adds pre-dewatering unit.

Background technology

In recent years, people are more and more higher to the requirement of environmental quality, and the management of various countries' environmental pollution is also constantly strengthened, and the biochemical processing of municipal wastewater and other organic sewages obtains general cognitive and popularization, yet these sewage treatment process can produce a large amount of residual active sludges.For the treatment and disposal of these residual active sludges, all relate to the thickening of mud.

In traditional dewatering technology of mud, general employing is carried out mud earlier and is concentrated, and carries out mechanical dehydration after the sludge digestion again.It is bulky to exist the anaerobic sludge digestion pond, and initial cost and running cost are higher, and the sludge dewatering effect is relatively poor, and the moisture percentage in sewage sludge height after the processing is unfavorable for the problems such as disposal that mud is follow-up.And the heat that usually produces in the winter time the time can not satisfy the insulation demand of anaerobic digester own.

Li Yaxin etc. ^[1](Li Yaxin; Yue Xiuping. flocculation agent is to the strengthening effect [J] of high-rate anaerobic reactor granular sludge. Environmental Pollution and Control; 2004; 26 (5): 333～335) studied the influence of flocculation agent to granular sludge in the anaerobic reactor; discovery can promote the growth of anaerobic digestion bacterium under the effect of an amount of flocculation agent.Li Baoshi ^[2](Li Baoshi. add the influence [D] that inert particulate and flocculation agent form anaerobic grain sludge under the normal temperature lower concentration water inlet condition. Chinese Marine University's environmental engineering, 2009.) inquired into and add the influence of flocculation agent to methanogenesis activity, after discovery adds the cationic quaternary ammonium salt flocculation agent, can improve the activity of anaerobic sludge, promote the activity of methanogen.Shi Yuejin ^[3](Shi Yuejin. the dehydration of sludge from wastewater treatment plant, anaerobic digestion and anaerobic composting [D]. environmental engineering system of Zhejiang Polytechnical University, 1999.) discover that when moisture percentage in sewage sludge was 86% left and right sides, the anaerobic sludge digestion effect was best, gas production rate is also the highest.Luo Gang etc. ^[4](Luo Gang, Xie Li, Zhou Qi, Sang Wenjing, Sun Jiawei. high temperature anaerobic CSTR reactor for treatment cassava alcohol waste water research [J]. Chinese water supply and drainage, 2008,24 (9): 13～16) studies show that, the anaerobism CSTR reactor that moves under the hot conditions can bear higher organic loading, can reach 14kgCOD/ (m ³D), have very strong anti impulsion load ability and anti-pH changing capability.

Summary of the invention

In order to address the above problem, the purpose of this invention is to provide and a kind ofly can significantly reduce the sewage water ratio, reduce the high concentration sludge Anaerobic Digestion technology of sludge volume, can obviously reduce investment and working cost, can reduce greenhouse gas emission simultaneously,

The high concentration sludge Anaerobic Digestion technology that mud is carried out the pre-dehydration of machinery of production renewable energy source.

Technical scheme of the present invention is: the high concentration sludge Anaerobic Digestion technology to mud carries out the pre-dehydration of machinery may further comprise the steps:

1. mud concentrates: the residue water ratio 99% above mud of sewage work is sent into the gravity concentration basin by sludge pump, and the moisture percentage in sewage sludge after concentrated is generally 97%, and when its water ratio reduced to 97% by 99%, the volume of mud can narrow down to original 1/3.Separated liquid supernatant is through being back to Sewage treatment systems;

2. mud dewaters in advance: described concentrated back mud is entered the dehydration machine room, dewatered by mechanical sludge dewatering equipment, the control moisture percentage in sewage sludge is 88%～90%;

3. anaerobic sludge digestion: the mud after the described dehydration is squeezed in the CSTR anaerobic sludge digester by sludge pump, kept that mixture pH carries out anaerobic digestion in the reactor under the condition of high temperature (about 60 ℃) about 7.0.

4. sludge dewatering: with sludge pump postdigestive mud is sent in the mechanical dewatering equipment, dehydration again, the final moisture content of the cake that generates further reduces, and is beneficial to the follow-up disposal of mud.

Advantage of the present invention and positively effect:

1. sludge dewatering is respond well, and sludge reduction is obvious;

2. take up an area of and lack, cost is low.The moisture percentage in sewage sludge that enters digester descends, and reduces the volume in anaerobic sludge digestion pond greatly, reduces the initial cost and the running cost of sewage work;

3. the pre-dehydration to mud can improve organic loading in the mud, is adopting the CSTR anaerobic digester that is suitable for the high concentrated, solid material to handle the advantage that then can give full play to this technology thereafter;

4. the ultimate disposal cost is low, reduces transportation cost, saves the landfill expense;

5. be beneficial to the recycling of mud, as marsh gas power generation, composting, agricultural, do building materials etc.

Description of drawings

Fig. 1 carries out the process flow sheet of the sludge anaerobic treatment process of the pre-dehydration of machinery to mud for the present invention.

Embodiment

Further specify the present invention by the following examples.

Mud concentrates: the excess sludge of sewage work (water ratio is more than 99%), and rely on sludge pump to send into the gravity concentration basin, the moisture percentage in sewage sludge after concentrating is generally 97%, and when its water ratio reduced to 97% by 99%, the volume of mud can narrow down to original 1/3.Separated liquid supernatant is through being back to Sewage treatment systems.

Mud dewaters in advance: concentrate back mud and enter the dehydration machine room, dewatered by mechanical sludge dewatering equipment, the control moisture percentage in sewage sludge is about 88%～90%.

Anaerobic sludge digestion: the mud after dehydration is squeezed into by sludge pump in the CSTR anaerobic sludge digester.Moisture percentage in sewage sludge after the pre-dehydration is lower, about 88%～90%, compares with traditional technology, can reduce the volume of anaerobic digester greatly, has improved the anaerobic digestion efficient and the unit volume biogas output of mud.

Sludge dewatering: with sludge pump postdigestive mud is sent in the mechanical dewatering equipment, dehydration again, the final moisture content of the cake that generates further reduces, and is beneficial to the follow-up disposal of mud.

Claims

1. the high concentration sludge Anaerobic Digestion technology that mud is carried out the pre-dehydration of machinery is characterized in that, concrete processing step is as follows:

1. the spissated technology of mud gravity:

The water ratio that the sewage work second pond is discharged is at the excess sludge more than 99%, send into mud gravity concentration basin, mud dependence mud scraper is scraped and is collected gravity concentration basin center, discharge by shore pipe then, by equalizing tank or the storage basin of sludge pumping to the desliming machine room, the water ratio that concentrates back mud is 97%, and supernatant liquor is separated and is back to Sewage treatment systems;

2. mechanical dewatering equipment carries out the technology of the pre-dehydration of mud:

To send into the dehydration machine room through the mud after the gravity concentration basin concentrates, and dewater by mechanical dewatering equipment, and make moisture percentage in sewage sludge be controlled at 88%～90%, the water after supernatant liquor is handled through washing unit is back to Sewage treatment systems;

3. anaerobic sludge digestion CSTR technology:

Mud behind filter-press dehydration is squeezed in the CSTR anaerobic digester by sludge pump, keeps that mixture pH carries out anaerobic digestion in the reactor under 60 ℃ about 7.0;

4. dewatering technology of mud:

With sludge pump postdigestive mud is sent in the mechanical dewatering equipment, dewatered again, the final moisture percentage in sewage sludge that generates is 75%.