CN103663890B

CN103663890B - Method for reinforcing acid production amount of residual sludge alkaline fermentation through adding NaCl

Info

Publication number: CN103663890B
Application number: CN201310637257.3A
Authority: CN
Inventors: 王淑莹; 金宝丹; 袁悦
Original assignee: Beijing University of Technology
Current assignee: Beijing University of Technology
Priority date: 2013-12-02
Filing date: 2013-12-02
Publication date: 2015-07-08
Anticipated expiration: 2033-12-02
Also published as: CN103663890A

Abstract

A method for reinforcing the acid production amount of residual sludge alkaline fermentation through adding NaCl belongs to the technology field of activated sludge decrement and anaerobic fermentation for providing an internal carbon source. The method comprises the following steps: introducing residual sludge into an SBR reactor, slowly successively pumping a NaCl-containing solution and an alkali-containing solution from two sides of the bottom of the device, and at the same time, starting a stirrer. Culture conditions comprise that the temperature is 20 to 30 DEG C, the pH is 8 to 10, and the ORP is -100 to -150 mv. The acid production amount of volatile fatty acid can be stably prolonged for a certain time. The method further improves the acid production amount under the residual sludge alkaline fermentation condition, and at the same time, solves the problem of short stable time of acid production of residual sludge fermentation.

Description

A kind of NaCl of interpolation strengthens excess sludge alkaline fermentation and produces sour metering method

Technical field

The present invention relates to a kind of strengthening excess sludge alkaline fermentation and produce sour metering method, belong to sludge decrement, anaerobically fermenting provides internal carbon source technical field.By the acting in conjunction of acidication bacterium, sea salt bacterium, improve the prolongation simultaneously of excess sludge hydrolysed ferment product acid amount and produce sour steady time, realize mud decrement simultaneously.

Background technology

Activated sludge process is a kind of usual way processing waste water at present, but adopts the problem of sewage work's ubiquity carbon source deficiency of active sludge treatment process, seriously constrains the operating performance of sewage work.

The method of general solution sewage work carbon source deficiency is divided into two kinds:

Method one: add outer carbon source, generally based on methyl alcohol, ethanol, acetic acid, the method solves the problem of sewage work's carbon source deficiency to a certain extent, improves the operating performance of sewage work, but adds increase working cost for a long time.

Method two: utilize excess sludge acidication to provide internal carbon source, the method fundamentally solves the problem of sewage work's carbon source deficiency, solves excess sludge process problem simultaneously.

Simple sludge hydrolysis, acidification not only voltaile fatty acid yields poorly, and unstable.Fermenting after certain pre-treatment being carried out to excess sludge for the domestic and international expert of this problem, under experiment proves alkaline condition, the organic solubility rate of excess sludge can be increased substantially, shorten the sludge fermentation time, but it is short equally to there is the excess sludge fermentation stability time in alkaline fermentation, the problem that voltaile fatty acid stripping quantity is limited, if think continuous use, input fresh sludge that must be regular continuously, gets rid of fermented sludge.

Adopt salinity method alkaline fermentation excess sludge, when once adding excess sludge fermentation, the output of sludge fermentation voltaile fatty acid can not only be improve, and the steady time of producing acid can be extended; According to regularly adding fresh sludge, getting rid of fermented sludge, also can increase substantially the output of voltaile fatty acid, adopt salinity method alkaline fermentation excess sludge more effectively can carry out mud decrement.The method not only solves the problem of sludge sewage technique carbon source deficiency, also solves a process difficult problem for a large amount of excess sludge of sewage work simultaneously.

Summary of the invention

Remain sludge fermentation under the present invention is directed to alkaline condition and produce the limited and problem that steady time is short of acid amount, propose a kind of NaCl of interpolation and strengthen excess sludge alkaline fermentation and produce sour metering method.Present method is by small-sized SBR device, and change and traditional add merely alkali to improve the fermentation rate of mud, add sodium-chlor is assistant medicament simultaneously, solves the problem of sludge fermentation steady time.

The one that the present invention proposes is added NaCl strengthening excess sludge alkaline fermentation and is produced sour metering method, and its feature is as follows:

1) getting SBR pilot scale mud is fermentation unit primary starting mud, its sludge concentration MLSS=8000-9000mg/L, pH=7-8, SCOD=30-40mg/L; After cleaning, mud index is SCOD=0-5mg/L, NH ₄-N=0mg/L, NO ₃-N=0mg/L, sludge concentration MLSS=8000-9000mg/L, then drop into mud in fermentation reactor 1, starts agitator 2 simultaneously and stir;

2) start NaCl compound pump 4.1 when excess sludge reaches mark scale in question response device, NaCl solution pumped into, controlling NaCl concentration in reactor is that 0.2-0.5mol/L, NaCl enter prescription formula for once to add;

3) configure the NaOH solution of 1-2mol/L in alkali chemical tank 3, after NaCl solution pumps into reactor and stirs 30-50min, NaOH squeezes in fermentation reactor by ejector priming 3.1;

4) keep fermentation reaction actuator temperature at 20-30 DEG C, pH of mixed=8-10, MLSS=8000-9000mg/L, ORP=-100 ~-150mv;

5) fermentation reactor 1 is in operation and detects TVFA, SCOD, NH ₄-N, PO ₄ ^3-index; Fermentation reactor 1 operation 5-6 days after, TVFA=1700-2200mgSCOD/L, SCOD=3500-4000mg/L, NH ₄-N=200-250mg/L, PO ₄ ^3-=50-60mg/L, and Absorbable organic halogens is looked and is fermented successfully for more than 6 days.

First add NaCl and add NaOH again after stirring 30-50min, microorganism cells osmotic pressure in reactor is made to raise on the one hand, there is molten born of the same parents' phenomenon in part microorganism, cellular component discharges in a large number, another part microorganism active is suppressed, and in cell, dehydrogenase activity declines, and newborn metabolism slows down, add the unlikely quick death of microorganism after NaOH, the microorganism of survival provides bacterial classification for follow-up domestication; On the other hand, hypersaline environment suppresses methanogen growth, makes sludge fermentation stop at souring stage;

Accompanying drawing explanation

Fig. 1 application apparatus schematic diagram of the present invention.

Embodiment

Application apparatus schematic diagram of the present invention as shown in Figure 1, wherein fermentation reactor 1, stirring rake 2, NaOH chemical tank 3, NaOH compound pump 3, NaCl chemical tank 4, salt compound pump 4.1, pH determinator 5, ORP determinator 6, thief hole 7.

Get pilot scale mud, its character is as follows: sludge concentration MLSS=8000-9000mg/L, pH=7-8, SCOD=30-40mg/L.After cleaning, sludge quality is as follows: SCOD=0-5mg/L, NH ₄-N=0mg/L, NO ₃-N=0mg/L, sludge concentration MLSS=8000-9000mg/L, drop into mud in fermentation reactor-1, starts agitator simultaneously and stir, fully mix to make active sludge and medicament.The NaOH solution of configuration 2mol/L, first by NaCl throwing device, in control device, NaCl concentration is pump in device by NaOH after 0.5mol/L, 30min, and pH controls at 9-10.

After sludge fermentation 5-6 days, TVFA=1700-2200mgSCOD/L, SCOD=3500-4000mg/L, NH ₄-N=200-250mg/L, PO ₄ ^3-=50-60mg/L, and Absorbable organic halogens is looked and is fermented successfully for more than 6 days.Add NaOH solution merely, ferment TVFA=1000-1500mgSCOD/L, SCOD=3000-3500mg/L, NH after 7-8 days ₄-N=200-250mg/L, PO ₄ ^3-=50-60mg/L.The visible NaCl of adding can improve the product acid amount of mud alkaline fermentation.

Claims

1. add NaCl strengthening excess sludge alkaline fermentation and produce a sour metering method, its feature is as follows:

1) getting SBR pilot scale mud is fermentation unit primary starting mud, its sludge concentration MLSS=8000-9000mg/L, pH=7-8, SCOD=30-40mg/L; After cleaning, mud index is SCOD=0-5mg/L, NH ₄-N=0mg/L, NO ₃-N=0mg/L, sludge concentration MLSS=8000-9000mg/L, then drop into mud in fermentation reactor (1), starts agitator (2) simultaneously and stir;

2) NaCl compound pump (4.1) is started when excess sludge reaches mark scale in fermentation reactor (1), NaCl solution is pumped into, controlling NaCl concentration in fermentation reactor is that 0.2-0.5mol/L, NaCl enter prescription formula for once to add;

3) configure the NaOH solution of 1-2mol/L in alkali chemical tank (3), after NaCl solution pumps into fermentation reactor and stirs 30-50min, NaOH squeezes in fermentation reactor by ejector priming (3.1);

4) keep fermentation reactor (1) temperature at 20-30 DEG C, pH of mixed=8-10, MLSS=8000-9000mg/L, ORP=-100 ~-150mv;

5) fermentation reactor (1) is in operation and detects TVFA, SCOD, NH ₄-N, PO ₄ ^3-index; Fermentation reactor (1) operation 5-6 days after, TVFA=1700-2200mgSCOD/L, SCOD=3500-4000mg/L, NH ₄-N=200-250mg/L, PO ₄ ^3-=50-60mg/L, and Absorbable organic halogens is looked and is fermented successfully for more than 6 days.