CN1911834A

CN1911834A - Prewarning and control method of active sludge expansion and biological foam in sewage treatment

Info

Publication number: CN1911834A
Application number: CNA2006100252722A
Authority: CN
Inventors: 谢冰; 张辰; 徐亚同; 王国华; 陆嘉竑; 戴兴春
Original assignee: SCIENTIFIC RESEARCH INST SHANGHAI MUNICIPAL ENGINEERING DESIGN RESEARCH INST; East China Normal University; Shanghai Municipal Engineering Design Insitute Group Co Ltd
Current assignee: SCIENTIFIC RESEARCH INST SHANGHAI MUNICIPAL ENGINEERING DESIGN RESEARCH INST; East China Normal University; Shanghai Municipal Engineering Design Insitute Group Co Ltd
Priority date: 2006-03-30
Filing date: 2006-03-30
Publication date: 2007-02-14
Anticipated expiration: 2026-03-30
Also published as: CN100528769C

Abstract

The present invention belongs to the field of environment controlling technology, and is especially active sludge bulking and foaming controlling method for sewage treating yard. By means of analysis and calculation on the active sludge data in sewage treating yard, the sludge bulking and foaming conditions are divided into three grades, so as to take corresponding measures to control active sludge bulking and foaming effectively and prevent and reduce relevant hazard and loss.

Description

Sewage treatment systems activated sludge bulking and bio foam early warning and control method

Technical field

The invention belongs to the environmental improvement technical field, be specifically related to a kind of Sewage treatment systems activated sludge bulking and bio foam early warning and control method.

Background technology

Activated sludge sewage processing system is easier to take place sludge bulking and bio foam phenomenon.These phenomenons not only have influence on the water quality of water outlet when taking place, and bring the view problem.But because the complicacy of genesis mechanism, analyzing its occurrence cause needs the long time, brings inconvenience for operation control.Present many sludge bulkings and foamy control method have tangible lag-effect all in sludge bulking with foam is a large amount of takes after taking place, the expense height of Tou Ruing not only, and also effect is undesirable.

Summary of the invention

The objective of the invention is to propose a kind of method that can carry out early warning and in time be controlled the sludge bulking and the bio foam phenomenon of mud and sewage treatment system,, improve treatment effect to reduce running cost.

Because activated sludge bulking and foamy produce a process is arranged, when people observe tangible sludge bulking and a large amount of foam, qualitative change has taken place in Sludge System in fact, control for the quantitative change process that causes qualitative change, can eliminate in bud producing expansion and foamy trend, be major technique thinking of the present invention.

The present invention observes according to long-term experiment, has selected to influence 3 significant parameters that sludge bulking and frothing take place in the activated sludge sewage processing system, tests and assesses, and determines its occurrence degree, judges its corresponding rank, sends different alarms simultaneously.These 3 parameters are to be easy to the representative parameter index measuring and observe in production practice, are respectively sludge volume index SVI, and subjective graded index of filamentous bacterium and aeration tank foam coverage degree are established the grade of early warning system with this.The early warning system rank is divided into three grades, is 150～200ml/gMLSS at SVI, and filamentous bacterium quantity is 4 grades, and aeration tank foam coverage degree (visual inspection) is to be first-degree alert below 30%, and this rank is sludge bulking and foamy early period of origination; When SVI is 200～300mL/gMLSS, filamentous bacterium quantity is 5 grades, aeration tank foam coverage degree be 30～50% o'clock be the secondary warning, this rank is sludge bulking and foamy evolution period, take appropriate measures and control; When SVI is greater than 300mL/gMLSS, filamentous bacterium quantity is more than 5 grades or 5 grades, and the foam coverage degree is 50% to be three grades of warnings or serious warning when above, is sludge bulking and foamy peak period here.

According to the different stage of alarm, take different control reclamation activitiess respectively, specific as follows:

When first-degree alert, need arouse attention this moment, can take 1. suitably to shorten mud age, promptly controls sludge retention time at 6-8 days; 2. reduce the time 10-20% of the oxygen section of holding concurrently, improve aerobic section aeration time 10-20%,, keep dissolved oxygen under the condition of 2～4mg/L to improve dissolved oxygen content; 3. increase the sludge volume (increasing 50-100%) of aeration tank, reduce sludge concentration, control to improve sludge loading more than 0.3kgBOD/kgMLSSd;

When secondary is guarded against, can take 1. to shorten mud age, promptly control sludge retention time 5-7 days; 2. increase aeration time 10-20%; 3. improve load, the 4. braking measure of dosing coagulant (flocculation agent) or sterilant, adds the sterilant clorox at i, and dosage press available chlorine content 8～10mg/L calculating in the mixed solution, is equivalent to 0.3%MLSS; Ii, add coagulant aids polyacrylamide PAM, dosage is 1～2mg/L;

When being three grades of whens warning, can take 1. to shorten mud age, control residence time 6-8 days; 2. add the sterilant clorox of capacity, dosage is pressed available chlorine content 10-12mg/L calculating in the mixed solution; Interception guipure (highly dense nylon wire) 3. is set in the aeration tank, the foam that swims in the surface, aeration tank and scum silica frost is carried out net catch and tackle, regularly gather foreign material and the residual body of foam on labor cleaning's filter.

Initial stage in sludge bulking and foam generation is carried out early warning, take different countermeasures respectively, it is eliminated in original state, can reduce sludge bulking and foam probability that takes place and the loss that causes significantly, be the effective ways of practicable cost-effective active sludge sewage work's sludge bulking and foam control.

The following table of filamentous bacterium quantity rank:

Rank	Richness	Explain
Rank	Richness	Explain	0	Do not have	Do not observe mycelia
1	Few	There is mycelia to exist, but only in some flco, finds accidentally	0	Do not have	Do not observe mycelia
1	Few		2	Some	The mycelia ubiquity, but all exist in the not all flco
3	Common	All flcos all have mycelia to exist, but density very low (1～5 mycelia/flco)	2	Some	The mycelia ubiquity, but all exist in the not all flco
3	Common		4	More	All flcos all have mycelia to have density medium (5～20 mycelia/flcos)
5	Abundant	All there be (a 20-100 mycelia/flco) in a large number in mycelia in all flcos	4	More
5	Abundant		6	A lot	Thread fungus is far away more than flco, (greater than 100 a mycelia/flco)

Description of drawings

Photo when Fig. 1 reaches 3 grades of warnings for certain activated sludge sewage processing system sludge bulking and foam, visible reaction tank surface have the floating foam of large number of biological to exist.

Fig. 2 is abundant for filamentous bacterium, reaches the photo of a 20-100 mycelia/flco.

Fig. 3 is for reaching 3 grades of whens warning, the photo that the reaction tank surface has oil slick to exist.

Fig. 4 is for being provided with the photo of interception guipure in the aeration tank.

Fig. 5 is through aeration tank face photo after the repair process, and wherein biological floating foam disappears.

Fig. 6 is that certain sludge of sewage treatment plant is between the phase of expansion and adopt SVI change curve after the measure of control.

Embodiment

The present invention is further described below in conjunction with example

Certain sewage work's designing treatment amount is 150,000 m ³/ d sets up three group reaction ponds separately, and 50,000 m are born in every group reaction pond ³The treatment capacity of/d.

Owing to do not set up early warning mechanism, break out sludge bulking in November, 2004, has large number of biological to float the foam (see figure 1) in the activated sludge reaction pond.This time sludge age in service be 11～14 days, MLSS concentration～3000mg/L, SVI surpasses 300mL/g after testing, filamentous bacterium is abundant, reaches 5 grades of (see figure 2)s, on the face of reaction tank pond the oil slick (see figure 3) is arranged.Be in three grades of warnings.

The measure of taking be at first reduce mud age to 6～8 days, the interception guipure is set in the pond foam that swims in the surface, aeration tank and scum silica frost are carried out net catches and tackle (see figure 4), SVI drops to 100～130mL/g, the filamentous bacterium richness is common, reaches 2～3 grades.SVI slowly rises to 175～220mL/g then, and every group reaction pond adds the 150kg clorox, presses available chlorine content 9mg/L calculating in the mixed solution, is equivalent to 0.3%MLSS (weight ratio w/w).SVI drops to below the 120mL/g after the dosing, and the filamentous bacterium richness is few, reach 1 grade and below, the reaction tank pond floating foam disappearance (see figure 5) of thing of looking unfamiliar.Fig. 6 is seen in the SVI variation during this section.

Claims

1, the early warning system of sludge bulking and frothing takes place in a kind of Sewage treatment systems, it is characterized in that the early warning system rank is divided into three grades, at SVI is 150 ~ 200ml/gMLSS, filamentous bacterium quantity is 4 grades, aeration tank foam coverage degree is to be first-degree alert below 30%, and this rank is sludge bulking and foamy early period of origination; When SVI is 200 ~ 300mL/gMLSS, filamentous bacterium quantity is 5 grades, aeration tank foam coverage degree be 30 ~ 50% o'clock be the secondary warning, this rank is sludge bulking and foamy evolution period, take appropriate measures and control; When SVI is greater than 300mL/gMLSS, filamentous bacterium quantity is more than 5 grades or 5 grades, and the foam coverage degree is 50% to be three grades of warnings or serious warning when above, is sludge bulking and foamy peak period here;

Here, SV1 is a sludge volume index, and the rank of filamentous bacterium amount is: 4 grades of 5-20 mycelia/flcos, 5 grades: a 20-100 mycelia/flco, 6 grades: greater than 100 a mycelia/flco.

2, the control method of sludge bulking and frothing taking place in a kind of Sewage treatment systems, it is characterized in that when first-degree alert, take 1. to shorten mud age, promptly controls sludge retention time at 6-8 days; 2. reduce the time 10-20% of the oxygen section of holding concurrently, improve aerobic section aeration time 10-20%,, keep dissolved oxygen under the condition of 2～4mg/L to improve dissolved oxygen content; 3. increase the sludge volume of aeration tank, reduce sludge concentration with the load that improves mud more than 0.3kgBOD/kgMLSSd, control;

When secondary is guarded against, take 1. to shorten mud age, promptly control sludge retention time 5-7 days; 2. increase aeration time 10-20%; 3. improve load, the 4. braking measure of dosing coagulant or sterilant, adds the sterilant clorox at i, and dosage press available chlorine content 8～10mg/L calculating in the mixed solution, is equivalent to 0.3%MLSS; Ii, add coagulant aids polyacrylamide PAM, dosage is 1～2mg/L;

When being three grades of whens warning, take 1. to shorten mud age, control residence time 6-8 days; 2. add the sterilant clorox of capacity, dosage is pressed available chlorine content 10-12mg/L calculating in the mixed solution; 3. the interception guipure is set in the aeration tank, the foam that swims in the surface, aeration tank and scum silica frost is carried out net catch and tackle, regularly gather foreign material and the residual body of foam on labor cleaning's filter.