Methods and Techniques Used in Effluent treatment plant and solid waste Management

    Pharmaceutical and biotechnology manufacturing plants discharge different types of effluents and solid wastes. These effluents and solid wastes should be handled and treated carefully because they can cause a major threat to environment and biodiversity.
As these wastes contain varieties of contaminants, if they are not treated before disposal to the environment, they can cause pollution.
Industrial wastes are also a cause of contamination of soils. Sludge formed in industrial process destroy vegetation and result in formation of lifeless areas on earth surfaces.
According to a report of Central Board for Prevention and Control of Water Pollution (CBPCWP), 1979, the industries of Mumbai accounts for 13% of total dump into water bodies. In Kolkata, 89% of wastes are of domestic origin. In Delhi, Yamuna receives about more than 200 million of untreated human wastes while the industries account for only 20 million liters of effluent. (Trivedi, R.K. and Goel,P.K. (1984) Chemical and biological method for water Pollution)
These wastes can cause various effects to the environment, some of which are:-

PHYSIO-CHEMICAL EFFECTS: -

Pollutants can impart color, taste and odor to the receiving water, thus making them unaesthetic and even unfit for domestic consumption and pH effects the chemistry of water often triggering chemical reactions resulting in the formation of unwanted product.

BIOLOGICAL EFFECTS:-

Addition of pollutants lead to the shift in flora and fauna due to homeostasis factor operating in aquatic systems. Most of the fresh water algae are highly sensitive to pollutants and their elimination modifies the prey-predatory relationship by breaking down the food chains. These result in change of whole plant and animal communities. The diversity of organism decrease due to presence of only few tolerant forms in the polluted conditions.

TOXIC EFFECTS:-

These are caused by pollutants such as heavy metals, biocides, cyanides and other organic and inorganic compounds which are determined to the organisms. These substances usually have very low permissible limits in water and their presence beyond this limit can render the water unfit for aquatic biota and even for human use.

It is mandatory for the industries to properly treat the wastes before its disposal. The Government has laid certain norms for proper discharge of wastes and officials make regular visits to the industries for inspection. In order to maintain these norms

               Types Of Wastes

Effluents:-   Waste water streams in pharmaceutical and biotechnology manufacturing depend on specific process and may include chemical reaction streams; product wash water; spent acid and caustic streams; condensed streams from sterilization and strippers; equipments and facility wash water and clean-in-place waste water.
Waste water generated from various sections of industries are carried in two separate drains to the Effluent Treatment Plant (ETP). One drain carries the process water from various blocks like:

1.Tablet and Capsule block
2.Liquid and Lozenges block
3.Dry Powder Injection block

      The other drain carries sewage discharges from     domestic wastes as well as purified water systems.

Solid Wastes:-   Formulation processes in the pharmaceutical industry result in the production of significant quantities of waste material. These include:

oRejected plastic drums
oRejected polyethylene
oRejected corrugated box
oRejected blister foil
oRejected aluminium foil
oRejected wooden box
oThermocol

Operation Of ETP

The capacity of the ETP is XYZ KL per day. The existing ETP consists of following tanks:-

1. Process Collection tank
2. Equalization Sewage tank
3. Oil and Grease tank
4. Equalization Process Tanks 1 and 2
5. Sewage Collection tank
6. Flash Mixer tank
7. Primary Tube Settler tank
8. Aeration tank
9. Saff Reactor tank
10.Secondary Tube Settler tank
11.Final Treated tank
12.Dry chemical sludge bed
13.Dry bio sludge bed

ETP also contains following equipments:-

Chemicals used in ETP:-

1.Caustic soda
2.Alum
3.Poly Aluminium Chloride
4.Poly Electrolyte
5.Urea
6.Di-Ammonium Phosphate
7.Jaggery
8.Sodium Hypochlorite

 
Treated Water
used for Irrigation

•The procedure adopted for operating the ETP:-

Switch on the panel of the Effluent Treatment Plant.

1-Process effluent from the manufacturing process receives to the collection tank and than transfer to the Equalization Tank through the Oil & Grease tank. Add Caustic to the equalization tank to raise the pH up to 10 - 11

2-Switch on the Effluent transfer Pump and allow the effluent from Equalization tank, continuously to Flax Mixer. The domestic waste received in the septic collection tank, is then transfer to the Aeration tank as well as the Saff reactor.

3-Add ALUM (Aluminum Sulphate) respectively to adjust the pH to7-8 and PAC (Poly Aluminum Chloride) to remove the color in the Flux Mixer.

4-  Allow effluent after adjusting pH will be sent to Primary Clarifier by gravity. The solids will be settled down at the bottom through the tubular type clarifier. Allow clean water (supernatant) will be sent to Aeration Tank by gravity.

5- Add urea and Di – Ammonium Phosphate (DAP) to the Aeration tank as well as SAFF Reactor daily, which acts as nutrients for the bacteria and beneficial for the bacterial growth.

6-Switch on the Air Blower for supplying the diffused air from bottom.

7- Allow supernatant water from secondary clarifier will be sent to the Feed Sump by gravity. Transfer the loads from the Feed Sump to the Pressure Sand Filter (PSF) and then to the Activated Carbon Filter (ACF).

8- Send the drains from both the clarifiers to Sludge Drying Beds.

9- Send the filtrate from the sludge drying beds progress to the equalization tank. The dried sludge is used as manure in the garden.

10- From the ACF filtered water will be collected in the Final Treated Holding tank.

11- Add dosing of Sodium Hypo Chlorite (1 % sol v/v) in the Final Treated Holding tank for chlorination.

12- Allow the chlorinated water from the Final Treated Holding tank will be used for irrigation purpose in the green belt.

               ANALYSIS OF ETP

We conducted certain tests to analyze the standard specifications as declared by the various governmental and non-governmental organizations. These tests include:-

1.PHYSICAL TESTS:- Take 10ml of treated effluent water in a clean and dry test tube. Check the clarity, color and odor of treated effluent water and record.

2. pH:- Take about 50ml of treated effluent water in a clean and dry beaker and measure the pH by a calibrated pH meter / Pencil type pH Meter .     

3. TOTAL DISSOLVED SOLIDS (TDS ) :
I.By Pencil type TDS Meter

II.Evaporating Method:-
Aim: To determine the total dissolved solids of given sample by Evaporating Method.
7
•Apparatus and Equipment:
 Evaporating dish
 Filter paper
 Muffle furnace
 Desiccator
 Laboratory Oven
 Hot plate
 Vacuum Pump.
 Digital analytical balance

PROCEDURE

Take an evaporating dish and ignite it at 550 +- 50oC in a muffle furnace for about 1 hour, cool in desiccator and weigh.(‘A ‘gm)

Filter the sample through glass fibre filter paper applying the suction.

Evaporate 50 ml of this filtered sample ( or more in case the solids are less than 25 mg/l ) in the preweighed evaporating dish on a water bath or a hot plate having temperature not more than 98oC.

Heat the residue at 103oC - 105oC in an oven for one hour and take the final weight after cooling in a desiccator  (‘B’ gm).
•Calculation:
                                                                    ( B  - A)  x  10,00,000                    
                   Total Dissolved Solid =       
                                              V

                    Where B = Final wt in gm
                               A = Initial wt in gm
                               V = ml of sample taken

4.TOTAL SUSPENDED SOLIDS (TSS):

Aim: To determine the total suspended solids of given sample.
Apparatus and Equipment:
 Gooch crucible / filter paper
 Laboratory oven
 Vacuum pump.
Digital analytical balance
Procedure:
• Weigh clean, dry Gooch crucible after drying it at 105oC for 2 hours and cool it to room temperature.(‘A ‘gm)
•Take 50ml of treated effluent water in a calibrated measuring cylinder.
•Filter the treated effluent water through the Gooch crucible or filter paper and then wash the crucible with 10ml purified water and dry the Gooch crucible at 105oC till consecutive weights are constant. Cool Gooch crucible in a desiccator and weigh (‘B’ gm)
Calculation:
                                                                     (B - A) x 10, 00,000                    
                   Total suspended solid =  
                                                                                 V
                    Where B = Final Wt in gm   ,    A = Initial Wt in gm
                                             V = ml of sample taken

5.DISSOLVED OXYGEN (DO) :

•Aim:In the presence of Oxygen, Manganous sulphate reacts with the alkali ( KOH or NaOH) to form a white precipitate of  Manganous hydroxide, gets oxidized to a brown coloured compound. In a strong acid medium Manganic ions are reduced by iodide ions, which get converted in to iodine equivalent to the original concentration of oxygen in the sample. The iodine can be titrated against Sodium thiosulphate using starch as an indicator.

•Apparatus and Equipments:
Conical flask
Burette
BOD bottles of 300 ml
1 ml pipette
250 ml measuring cylinder
Starch solution
Manganese Sulphate
Alkali iodide azide solution
0.025M Na2S2O3
Potassium bi iodidate
Concentration Sulphuric acid
Potassium Iodide

•Preparation of Reagents : 

Preparation of Manganous Sulphate solution: Weigh accurately 100 gm of Mnso4 4 H2O in 200 ml of purified water and filter.

Preparation of Alkali iodide azide solution: - Dissolve 500 gm NaOH or 700 gm KOH and 150 gm of KI in purified water to make 1 liter of solution (a). Dissolve 10 gm of NaN2 in 40 ml of distilled water ( b ).Mix the two solution (a) and)(b)

Preparation of Potassium Iodide solution:            Dissolve 100 gm KOH and 50 gm KI in 200 ml boiled water

Preparation of Standard 0.025N Sodium Thiosulphate solution:
Dissolve 24.82 gm Na2S2O3 5 H2O in boiled purified water and make up the volume to 1 liter, Add 0.4 gm of borax or a pallet of NaOH as a stabilizer,  this is 0.1 N stock solution. Dilute it to 4 times with boiled distilled water to prepare 0.025 N solutions (250 to 1000 ml). Keep in a brown glass Stoppered bottle.

Starch solution: Dissolve 1 gm of starch in 100 ml of                      warm (80 oC - 90 oC) purified water and add a few drops of formaldehyde solution.
•Procedure:

Take effluent sample in 300 ml BOD bottle carefully, to avoid any kind of bubbles.                                                                                                                                                                                                                                                                                                            
Remove the air bubble in the bottle after placing the stopper by wrapping
.
Add 2 ml MnSO4 solution then add 2 ml alkali azide reagent by using separate pipettes for each solution.

When ppt. appear, stopper carefully to exclude air bubbles and mix by inverting the bottle for few minutes.
Keep the bottle aside to settle down the precipitate.

When precipitate settled sufficiently then add 2 ml con. H2SO4 and restopper the bottle and shake well to dissolve the ppts. Completely.

Take 200ml of this sample in a conical flask and titrate the contents against the previously standardized Sodium thiosulphate solution using Starch solution as an indicator. At the end of titration the colour of solution changes from deep blue to colorless.
•Calculation:

              Burette Reading x 8000 x Normality of Na2S2O3                                               
DO  = 
                                                                 Ml of sample taken

6. BIOLOGICAL OXYGEN DEMAND (BOD):
•Aim :  To measure the dissolved oxygen demand
Biochemical Oxygen Demand (BOD) is the measure of the degradable organic material present in water and can be defined as the amount of oxygen required by the micro organism in stabilizing the biologically degradable organic matter under aerobic condition.  The principle of the method involves measuring it for 3 days at 20o C ± 1oC
•Procedure:

Take 2 liters of purified water in a plastic bucket/ container and purge compressed air for about 24 hrs.

Add 1ml of each phosphate buffer, magnesium sulphate, calcium chloride, ferric chloride solution and 1 ml of sewage water for each one liter. and mixed thoroughly.

Neutralize the sample to pH around 7.0 by using 1M NaOH or H2SO4.

Since the DO in the sample is likely to be exhausted it is necessary to prepare a suitable dilution of the sample according to the expected BOD range.

Prepare dilution in a measuring cylinder and mix the content thoroughly. fill two sets of the BOD bottles.

Keep one set of bottles in BOD incubator maintained at 20oC for 3 days and determine the DO content in other set of bottle immediately.

Determine DO of the incubated sample bottles after the completion of 3 days incubation.
For determination of DO content all the sample shall titrated with 0.025M Na2S2O3 using the starch solution as an indicator till the colour changes from blue to colorless

•Calculation:                               
                    BOD = ( B1 –B2 ) -  (D1-D2)            
   Where,
B1 = D.O of dilution sample before incubation (1st day)
                  B2 = D.O of diluted sample after incubation (3rd day)
                  D1 = D.O of blank before incubation (1st day)
                  D2 = D.O. of blank after incubation (3rd day)
                  F = Dilution factor
                                   N of Thiosulphate x 8 x 1000    dilution for BOD(600 ml)
                    F =                                                    x
                                            ml of sample                      sample taken for DO  

7. CHEMICAL OXYGEN DEMAND (COD) :

•Aim: To determine chemical oxygen demand of the sample, boil mixture of potassium dichromate and sulphuric acid destroys most types of organic matter. A sample is refluxed with known amount of potassium dichromate and sulphuric acid the excess of potassium dichromate is titrated with ferrous ammonium sulphate. The amount of oxidisable organic matter, measured as oxygen equivalent is proportional to the potassium dichromate consumed.
•Apparatus and Equipments:
                   Condenser
                    Flat round bottom flask
                    Heating mental / Water Bath
                    Standard potassium dichromate solution (0.25 M)
                    0.1 M Ferrous Ammonium sulphate solution
                    Con. Sulphuric acid
                    Ferroin indicator
                    Mercuric sulphate
•Preparation of Reagents:

Standard 0.25 M Potassium Dichromate solution
Dissolve 12.259 gm K2Cr2O7 analytical reagent grade      previously dried at 103oC for 2 hrs. and dilute it to 1000ml with purified water.

0.1 M Ferrous Ammonium Sulphate solution
                Weight accurately 39.2 gm of Fe (NH4)2 (SO)4 6H2O and dissolve it in 200ml of purified water, add slowly 20 ml of Con. H2SO4 and cool, then dilute it to 1000ml.For standardization, dilute 10.0 ml of K2Cr2O7 to about 100 ml, add 30 ml of Conc. H2SO4, and titrate with ferrous ammonium sulphate using ferroin as an indicator. 

Ferroin Indicator
Dilute 1.485 gm of 1,10-phenonthroline and 0.695 gm of ferrous sulphate (FeSO4.7H2O) in purified water to make 100 ml of solution.
Sulphuric acid

H2SO4 Concentrated ( specific gravity 1.84)
Mercuric Sulphate
  HgSO4, solid
Silver Sulphate
  AgSO4, solid
•Procedure: 
Place 0.4 gm mercuric sulphate (HgSO4) in refluxing flask and dissolve it in 5 ml con. H2SO4.
Add 20ml treated effluent water (sample) and swirl to mix.
Add 10 ml 0.25M standard potassium dichromate solution.
Carefully add 25 ml of Con. H2SO4 cool the refluxing flask in ice bath.
Add some glass beads and shake the mixture then attach the flask to condenser and reflux the mixture for 2 hrs.
Cool the flask to room temperature and then wash interior side of the condenser with 80 ml purified water.
.Titrate the excess of potassium dichromate with pre standardized 0.1M ferrous ammonium sulphate solution using 3 to 4 drops ferroin indicator until the colour changes from blue-green to reddised-brown.
In the same manner reflux 20ml of purified water as a blank simultaneously with the sample.

•Calculation:
                           C.O.D. =             (a - b) x M x 8000                                                           
                                                   Volume of sample (ml)         
where,
         a = Volume of Fe(NH4)2(SO4).6H2Oused for blank
         b = Volume of Fe(NH4)2(SO4).6H2Oused for sample
                    M =Molarity of 0.1M Fe(NH4)2(SO4).6H2O

8. OIL AND GREASE:

•Aim: To measure the oil and grease content of given sample.
•Apparatus and Equipments
Evaporating dish
Separating funnel
Petroleum Ether
Water bath
•Procedure :
Take 250 ml of sample in 500 ml separating funnel.
Acidify the sample by adding 2 to 3 ml of HCl (1:1) and shake well.
Add 50 ml of petroleum ether in the separating funnel shake vigorously for 2 minutes.
Allow the ether layer to separate. Collect the aqueous layer into another separating funnel. Add the 50 ml of ether into aqueous layer of the separating funnel again shake it for 2 min and collect the ether layer into the separating funnel containing previous ether layer
Pass the ether layer through the Sodium sulphate bed previously moisten with ether and collect the ether layer in pre dried and pre weighed evaporating dish (W1).
Evaporate all ether extract on water bath till dryness.
Put evaporating dish in the oven at 105o C for complete dryness. Cool the evaporating dish in a desiccator and weigh the evaporating dish (W2).

•Calculation :-

                                                  OIL and GREASE  =    (W2 – W1)  X  1000  X  1000
                                                          ml of sample

SOLID WASTE MANAGEMENT

Manufacturing processes in pharmaceuticals and biotechnology industries generate hazardous as well as non-hazardous solid wastes that include aluminium foils, polyethylene, chemicals etc. These waste materials need to be disposed off properly otherwise they can cause serious problems to the environment.

Apart from these production wastes, solid wastes are also obtained in the form of sludge during effluent treatment. This sludge can be categorized into:

•Bio sludge:- This is taken into use as manure in                                 the garden.

•Chemical sludge:- This is a hazardous waste which is stored for a few days and then incinerated through some approved outer agency.

      
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                     THE END

Dheeraj kumar shukla