utilization of paper industry effluents as water reducing agents in concrete

Name: LIKHITH.J.M USN : 4AI07CV404 Guide: Dr.M.NAGESH

Introduction Need For Technology Transfer Experimental Work

Characteristics Of Commercial Admixtures Characteristics Of Paper Mill Effluent Effect Of effluents On The Setting Time Of Concrete Workability Of M30 Concrete In Terms Of Slump Value For Various

W/C Ratio Compressive strength

Conclusion References

Paper industry has tremendously expanded in the last five decades

They use wood & agriculture residues in paper making. In the process, lignin present in the wood is dissolved & thus

loosens the cellulose fibers. Lignin is converted into other forms during the process. Fibers require bleaching for making into white paper. Spent liquor is collected for recovery. Discharges huge volume of colored and highly toxic waste water

in the environment

1. Wood chip screening

2. Wood chip cooking

3. Pulp washing and screening

4. Bleaching and drying

5. Expedition

The process of pulp washing gives rise to dark brown colored waste known as Stock Waste or Black Liquor.

Toxicity of effluents arise due to presence of low and high molecular weight chlorinated compounds generated during the manufacturing process.

Medium & high molecular weight CL remains unaffected to treatment process and pass into water bodies with effluents.

Slow decomposition of these, releases toxic & bioaccumable phenols, dioxins & carcinogenic compounds

Regular monitoring of pollution parameters , is thus necessary in effluents w.r.t TSS, BOD, COD, color etc, to maintain safety.

Receiving water bodies will be aesthetically unpleasant.

Chronic toxicity to fishes and other aquatic species

Organic & inorganic chemicals in effluents damages the plant

Inhibits germination & seedling growth.

In order to reduce the cost of treatment of effluent and to avoid polluting the water bodies ,thus it becomes worthwhile ,to utilize the effluent as a water reducing agent.

Eventhen, PME contains Lignosulphonates, which are known as water reducing agents .

The effects of SPME & LPME on properties like setting time, workability & compressive strength were studied.

The results are compared with MLS & SNF. The experiments include: a) Effect of effluent, MLS, SNF on setting time of cement at

various dosages.

b) Effects on the workability of concrete mix determined by

slump test.

c) Effects on compressive strength at 3,7 & 28 days at various

w/c ratios & dosages.

DISCUSSION:

Addition of effluent has no remarkable effect on the setting time of cement & is well within the BIS limits

DISCUSSION:

• Addition of PME & CA exhibit improvement in the workability compared to control mix.• Slump increases with increase in the dosage level.• Slump value of concrete with effluent is comparable to CA.

With use of additives in concrete, final slump value was found to be comparable with the initial slump value of control mix, even after 30 minutes.

Even after the lapse of 30minutes with the addition of admixture, we get workable concrete, which was not possible for control mix.

One of the benefits of using reducing agent is to get better workability at the same w/c ratio or by reducing the w/c ratio at a given workability. The addition of paper mill effluent at same w/c ratio significantly improves the workability as compared to the control mix

CONCRETE AT 0.45 W/C RATIO

At 0.4 W/C ratio

Discussion: In the above cases, concrete with admixtures shows the strength

in all 3,7 & 28 days, which can be compared to the control mix. The final strength gain of concrete with SPME & LPME is more

or less same to that shown by concrete with CA. Studies reveal that ,with the use of effluents, 28 days compressive

strength shows same, or in some case, more than 10% increase as compared to control mix.

From results obtained, it is seen that PME containing Lignosulphonates can be effectively use as an admixture in concrete.

Setting behavior of cement is within the BIS limits on addition of effluent.

Addition of effluent has also remarkable effect on concrete, as it increases the workability and 28 day compression strength of concrete.

The characteristics of PME is well comparable with commercially available admixtures.

It can be said that effluents , which would have produce adverse effects on environment, if untreated, can be directed for an effective use in concrete, thereby reducing its concentration in the environment.

Agarwal .S.K and Kiran Patel.”Utilization Of Paper Industry Effluent As Water Reducing Agent In Concrete”. NBM & CW, volume 30, issue 9, April 2008:Pg 62-68

Baruah B.K and Das .M .” Study On Impact Of Paper Mill Effluent On Germination Behavior And Seedling Growth Of Crop Plant, “ Pollution Research Journal,Volume 22,issue4, October 2008 :Pg 65-68

Shetty .M.S.” Concrete Technology ,Theory And Practice” S.Chand & Company.

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