Based on the information presented, an old sludge could possibly be the reason for your observation. It might help if you reported the sludge age. However, since you are treating an industrial waste, the reason could be that the influent may also contain inorganic solids and you may want to check the ratio of VSS to NonVSS in your influent.

grrun

One thing to check if you haven't is what does another lab say about the level.  It would be a good QC check.  What is the MLSS level you measure?  What are the dissolved solids levels at that point.  That 10000 mg/L is going somewhere.

I don't think that I understand what the problem is that we are trying to find a solution for. Is the secondary clarifier discharge outside of some control limit? Without knowing why you are concerned about the MLSS/MLVSS ratio (a 30 day sludge age does not seem too unreasonable for an extended aeration plant), I would carefully and slowly reduce sludge age to see if the change reduces the turbidity in the secondary clarifier discharge. If the clarifier discharge turbidity is not the concern, ignore my advice and describe the reason you have focused on the MLSS/MLVSS ratio.

grrun

Dear all

My concern is mainly on Turbidity that affects my RO operation.I thought this low MLVSS/MLSS ratio could be reason for this.
Also i could not understand why pH of the clarifier outlet(8.5) is higher than the feed(6.5to 7.5).

The MLSS level is 7000 ppm/TDS is 8500 ppm.

Dear Shasen,

turbidity maybe a direct result of the increase in pH leading to floc erosion and better conditions for producing stable colloid suspensions. (the suspended particles in wastewater treatment are usually negatively charged, which is increased increasing the pH leading to electrostatic stabilization).
You should consider dosing acids into the activated sludge process to counteract the pH shift. Probably organic acids are biodegraded.

You should start with the actual composition of the industrial wastewater if you would like to solve your problems.

KInd regards
T. Sobisch

dear shasen
it seems that inert material is accumulate in your aeration tank. waste some sludge from the calrifier on daily basis and develop new bio mass. SRT in ASP is 20 - 25 is good.

best of luck

Dear Shasen,

the biodegradation of organic acids will shift the pH to higher values by conversion of the carboxylic group to carbon dioxide. Floc erosion at higher pH is due to electrostatic stabilization as explained.

Kind regards
T. Sobisch

Dear all,
The reason for the turbidity and elevation in pH is identified.
The effluent contains sodium acetate and when biodegradation takes place the co2 liberates and combines with Na to form sodium carbonate that elevates the pH.
In turn due to HIgh pH and presence of Sodium carbonate, a strong dispersant,floc destabilisation and turbidity occurs.
now i think i need  focus to control the acetic acid source to knock out pH raise and turbidity.
ALso now there is improvement in MLSS/MLVSS ratio as i  reduced the sludge age to around 25 days by excess sludge wasting.
Hope i can still improve my system and i am working towards it. can any body suggest to maintain the pH at this condition by introducing inorganic acids directly into the aeration system if at all i am unable control acetic waste at the source.

Not sure what your acetic source is, but we have been working on removing acetic acid from textile processes by a combination of counterflow washing and initial use of mineral acids.  Just reviewing the process can save 70% of the acetic acid use.  The process is rarely optimized and until you point out the up to $1 Million dollar savings per year, you get little interest in fixing the problem.

Dear vin_saini

my concern is that due to high pH turbidity occurs in the clarifier outlet.