ETP for pharma formulation unit

Wastewater Management System

Wastewaters generated Cosmos will be generating the following wastewaters (see tables-1 & 2 for details):

1. Process effluent: 44.3 (say 50 ) m3/day2. Domestic effluent: 11-15 m3/day3. Non-process wastewater with quality closer to DM water: 60 m3/day4. Non-process wastewater with quality closer to raw water: 57 m3/day 5. Non-process wastewater with high TDS: 9 m/day

Table-1: Process Wastewater S.No. Source of the wastewater Quantity

(m3/day)Remarks

1. Wash water from external washing of vials of B-lactum

9.6 Need proper treatment prior to disposal

2. Wash water from external washing of vials of Oncology


3. From tablet coating through use of RO water


4. From bin washing through use of RO water


5. From dry granulation through use of RO water


6. From quality control through RO water use


7. From compression through use of RO water


8. From small utensil washing through RO water use


9. From solution preparation through RO water use


10. From cleaning in laundry through use of RO water


11. From miscellaneous sources through RO water use


12. CIP of Lyophilizer with RO water


13. From tablet coating through use of RO water


14. From loading through use of RO water


15. From dry granulation through use of RO water


16. From quality control through RO water use


17. From small utensil washing through RO water use


18. From miscellaneous sources through RO water use


19. From loading area through use of pure steam


20. From the SIP of liophilizer by pure steam


Total 44.3 Say 50 m3/day

Table-2: Non-process wastewaters and recyclable watersS.No. Wastewater/condensate stream Quantity

Recyclable as boiler feedwater/softwater

Recyclable as raw water

Rejects

1. Multigrade filter backwash water --- 14 ---2. UF reject stream and UF backwash

water--- 24.8 (19.2+5.6) ---

3. Regeneration wastewater of softwater plant

--- 2.6 1.4

4. Boiler blowdown water --- --- ???5. Cooling tower blowdown water --- --- ???6. DM water plants regeneration

wastewaters--- 15.7 (11+4.7) 7.7 (5+2.2)

7. Reject streams of RO plants 18.5 (12.9+5.6) --- ---8. Residual water of WFI plants ??? (..+..) --- ---9. Residual water of pure steam

generators??? (..+..) --- ---

10. Vial washing water 20.5 (12.8+7.7) --- ---11. Water from BUNG processors 13.5 (9.0+4.5) --- ---12. Autoclaving of seals, utensils, etc. 2.2 --- ---13. Vial washing with WFI in Oncology 2.3 --- ---14. CIP water of lyophilizer with WFI in

Oncology3.0 --- ---

Total >60 57.1 >9.1

Non-process wastewater of quality closer to DM water will be generated at the following locations:

1. Reject streams at the RO plants of both B-lactum and Oncology units (18.5 m3/day)2. Washwater generated at Vial washing and BUNG processors in both B-lactum and Oncology

units (34 m3/day)3. Water for injection used in the CIP of lyophilizers and in the vial washing of Oncology (5.3

m3/day)

4. Steam condensate generated at the autoclaving of seals, utencils, etc., in B-lactum unit (2.2 m3/day)

5. Residual water blown down from the water for injection and pure steam generating units (quantity not known)

These waters are the least polluted and have very low or negligible TDS. These will be collected separately and reused as makeup boiler feed water and also as makeup water in the circulating cooling water systems and cooling towers. Return steam condensate will be the main source for the boiler feed water. In case of insufficiencies, soft water will be used in the circulating cooling water systems.

Non-process water with quality closer to raw water will be generated at the following locations:

1. Backwash water of the multigrade filter (14 m3/day)2. Reject stream of the ultrafilter (24.8 m3/day)3. Backwash stage and rapid rinse stage wastewater from the regeneration of the ion exchange

resin beds of the soft water plant and of the DM water plants (18.3 m3/day)

These wastewaters have slightly higher TSS levels and otherwise better than the raw water in quality. These waters will be collected into a sump. From there, these waters will be pumped, filtered through a multigrade filter and taken back into the raw water tank for reuse as raw water.

Non-process wastewater with high TDS will be generated at the soft water plant and at the DM water plants in the chemical run and rapid rinse stages of the ion exchange resins regeneration. These wastewaters will be collected and reused in place of domestic water in all the toilet flushes and urinals and ultimately allowed to enter the domestic wastewater generated.

Of all the wastewaters generated, only two types of wastewaters, namely process wastewaters (50 m3/day) and domestic wastewaters (11-15 m3/day) need treatment in the effluent treatment plant to comply with the prescribed effluent standards and proper disposal. Characteristics of the typical process wastewaters are shown in table-3. Domestic wastewater has been considered to have the characteristics shown in table-4 for the design purposes.

Characteristics of the process wastewaterS.No. Parameter (units) Sample-1 Sample-2 Sample-31. COD (mg/L) 189 2978 2352. BOD3 at 27C (mg/L) 22 975 643. Total –P (mg/L as P) <0.2 <0.2 0.464. TKN (mg/L as N) 8.74 2.94 2.765. Nitrate (mg/L as N) 0.37 4.8 2.776. Nitrite (mg/L as N) <0.5 <0.5 <0.57. Alkalinity (mg/L as CaCO3) 8 20 278. Acidity (mg/L as CaCO3) 6 13 89. TDS (mg/L) 316 896 23810. TSS (mg/L) 4 5 2511. Sulfide (mg/L) <1.0 <1.0 1.1

12. Phenolic compounds (mg/L) 0.03 0.08 0.313. Oil and grease (mg/L) 1.4 12.1 5.3

Table-4: Characteristics of the domestic wastewater considered in the STP design

S.No. Parameter Value

1. TSS (mg/L) 300

2. VSS (as % of TSS) 65

3. BOD5 at 20°C (mg/L) 250

4. COD (mg/L) 450

5. TKN (mg/L) <35

6. Total-P (mg/L) 1-7

Scheme of treatment for the wastewaters

The process wastewaters will be collected into a detoxification tank. In this tank the wastewater will be dosed hypo for the detoxification and maintained for the desired minimum contact time. The detoxified wastewater will be allowed to overflow into a dechlornation sump, wherein the wastewater will be dechlorinated (through dosing sodium metabisulfite). Dechlorinated wastewater will then be pumped and taken into an up-flow anaerobic filter. Depending on the need, phosphoric acid, urea and even the other micronutrients will also be dosed into the wastewater at this place prior to the pumping.

Treated effluent of the anaerobic filter will be allowed to overflow into an Activated Sludge Treatment unit (ASP). Both the aeration tank and the secondary clarifier of this ASP will be integrated into a single unit. Diffused aeration system will be used for the supply of the air required for both mixing and oxygenation. Treated effluent of the ASP after clarification will be filtered through an upflow multigrade filter and allowed to flow into a subsurface flow constructed wetland system under gravity. Treated effluent of the constructed wetland system will be collected into a sump, and, from the sump, as and when required, the treated effluent will be pumped and used for irrigation of the green belt plantation, hedges and lawns. Excess of the treated effluent, if any is left, specially during odd weather, will be allowed to drain water along with the storm water.

Domestic wastewater of the plant will be collected into a small pit and from there pumped into a 2-stage baffled anaerobic reactor. Treated effluent of this reactor will be pumped and taken into the ASP of the effluent treatment plant for further treatment and disposal along with the process wastewater.

Sludge accumulating in the upflow anaerobic filter and in the upflow anaerobic filter, and excess sludge of the ASP will be drained into an aerobic sludge stabilization and thickening pit. Diffused air will be used in the sludge pit for the sludge stabilization. Clear wastewater overflowing the sludge pit from the thickening process will be allowed to flow into the domestic wastewater pit for pumping and treatment along with the domestic wastewater. The stabilized sludge of the pit will be dredged out and disposed off through using as soil conditioner in the green belt plantations.

The Effluent Treatment Plant

The effluent treatment plant has been designed for treating 50 m3/day of process wastewater and 11-15 m3/day of domestic wastewater. The schematic process and material flow diagram of the Effluent Treatment Plant (ETP) used is shown in figure-1.

The Effluent Treatment Plant proposed will include the following units:

1. Detoxification tank (with provisions for hypo dosing)2. Dechlorination sump (with provision for dechlorinator dosing) and pumps 3. Upflow anaerobic filter4. Domestic wastewater pit and pumps 5. 2-stage baffled anaerobic reactor6. ASP (activated sludge treatment plant) with integral secondary clarifier 7. Multigrade filter8. Sub-surface flow constructed wetland system9. Treated effluent sump and pumps10. Sludge thickening and stabilization pit11. Diffused aeration systems (3 numbers)

Dimensional and capacity details of the facilities of the ETP

Detoxification tankIt is within the boundary limits of the process and industrial project consultant. However the tank should have provisions for the overflow of detoxified wastewater into a dechlorination sump. Further, at the outlet end of the detoxification tank, a provision may be made for the monitoring of residual chlorine. Residual chlorine in the overflowing water will be maintained at the desired level through the dosing of hypo in the detoxification tank.

Dechlorination sump and pumpsThis sump can be an integral part of the detoxification tank (as a second compartment) receiving the overflows from the detoxification tank. Effluent holding capacity of this sump can be 5 m3. Provisions may be made in this tank, for the dosing of sodium metabisulfate and also the nutrients (urea, phosphate and other nutrients if needed), for mixing the tank contents and for monitoring the residual chlorine in the dechlorinated wastewater. A 10 m3/hour capacity pump (with one standby pump provision) may be used for pumping the dechlorinated effluent into the upflow anaerobic filter. Dosing of the sodium metabisulfite, monitoring of residual chlorine and pumping of the dechlorinated wastewater may activated by the liquid level in the sump.

Upflow anaerobic filterThis filter will be of 4 m x 4 m x 4.5 m liquid depth (0.3 m freeboard). It will have a central vertical inlet pipe of 150 mm internal diameter delivering the wastewater at the bottom below the packed medium. The packed medium will be supported over a stainless steel metallic grid of 8 to 10 mm size openings. Thickness of the packed medium will be 2.0 m, and below the packing, 2.0 m free space will be allowed for facilitating storage of the sludge and for the maintenance of a sludge blanket. Treated effluent will be siphoned off from 0.3 m below the liquid surface into the ASP. Plastic medium of 20-30 mm size and density slightly higher than that of water will be used. Bottom of the tank will be sloped towards center by 1 in 10/12. A drain will be provided at the bottom in the center of the tank for facilitating occasional draining out of the accumulated excess sludge.

Domestic wastewater pit and pumpsAll the domestic wastewater generated will be allowed to flow under gravity into this pit. This pit will have about 3 m3 capacity. A pump (and one standby pump) of 30 m3/hour capacity will used for pumping out the accumulated domestic wastewater. As and when the wastewater pit gets filled with the domestic wastewater, the pump will get activated and the wastewater will be pumped and emptied into the 2-stage baffled anaerobic reactor.

2-stage baffled anaerobic reactorThe two stage baffled anaerobic reactor will have an effluent zone of 4.5 m depth and a free board of 0.3m. Each of the stages will be a rectangular chamber of 2.0 m length and 2.0m width. The incoming wastewater will be released at the bottom at about 0.3m height in the stage-1 chamber and allowed to rise upwards. From the top of the stage-1 chamber without disturbing the floating scum layer the wastewater will be withdrawn subsurface at 0.3 depth from the liquid surface and released at the bottom of the stage-2 chamber. From the top of the stage-2 chamber, the wastewater will be withdrawn

subsurface at 0.3 m depth from the liquid surface and discharged into the activated sludge process (ASP) unit. Please see figure-2 for details. The piping used will be of 250 mm internal diameter. Both the stages of the baffled anaerobic reactor will have a sloping bottom (1 in 10/12) towards the center and at the center in the bottom drains will be provided for draining out the accumulated excess sludge.

ASP (activated sludge treatment plant) with integral secondary clarifier

A tank of 4m x 4m x (4.3m + 0.5m) dimensions and 68 m3 liquid holding capacity will be used as the ASP. A cylindrical tube of 2.5 m internal diameter and 2.5 m liquid depth and 0.5 m free board open from both the sides and located in the center of the aeration tank will be used as the secondary clarifier. At the bottom of the clarifier for deflecting the air bubbles while allowing sliding of the settled sludge back into the aeration tank a circular plate of 3 m diameter will be used below the cylindrical secondary clarifier at 1.5 m height from the bottom. Top face of this circular plate will be made conical in order to ensure sliding of the settled sludge into the aeration tank. On the top at the liquid level a clarified effluent trough running along the diameter with overflow weir on both the sides will be provided. This trough will carry the clarified effluent into the multigrade filter for filtration. For facilitating aeration, a diffused aeration system will be provided in the aeration tank. Provision will be made for draining out the excess activated sludge in the form of mixed liquor into the sludge pit. Please see figure-3 for details. Secondary clarifier in the ASP can be plastic sheet on angled steel frame.

Clarified secondary effluent will be collected from the secondary clarifier and allowed to flow into the multigrade filter for the filtration.

Two stage multigrade filterEffluent from the secondary clarifier will be passed through a two stage multigrade filter in order to remove suspended solids and also reduce the coliform count. In both the stages the wastewater will flow upwards through the filter bed. Each of the two stages will be (2 m x 1.5 m) rectangular cells and have a hopper bottom (1 in 10/12 slope towards center). The filter will be covered by a concrete slab with a manhole for facilitating occasional maintenance.

Both the stages of the multigrade filter will have a 1.2 m thick graded gravel layer, a bottom sludge storage space of 1.5 m depth and a top filtered water storage reservoir (of 1.0 m depth). Freeboard of these units will be 0.6 m. See figure-4 for details. Size of the gravel used will be decreased from stage-1 to stage-2 and from bottom to top in the beds. Please see table-5 for the profile of the graded gravel beds. The graded gravel bed will be supported on a metallic grid of 8-10 mm size openings provided at 1.5 m height from the bottom.

Table-5: Profile of the graded gravel used in the 2 stage multigrade filter

Stage-1 Stage-2

Layer thickness

in mm

Size in mm

Layer thickness

in mm

Size in mm

200 20-40 200 20-40

150 16-8.0 150 16-8.0

850 3.5-7.0100 3.5-7.0

750 1.5-3.0

Both the stages will be provided with drains at the bottom in the center for facilitating the filter back washing and removal of the accumulated sludge. A central vertical inlet pipe (of 125 mm internal diameter), capped at the top and connected to the outlet of the previous unit (previous stage of the filter or the clarified effluent piping of the secondary clarifier) will be used to deliver the influent wastewater below the graded gravel bed layer. Form the filtered water reservoir of the first stage, water is extracted subsurface and loaded as influent into the central vertical inlet pipe of the second stage. Form the second stage, the filtered water is allowed to overflow and flow under gravity into the subsurface flow constructed wetland system. Please see figure-4 for details. Inlets of both the stages of the multigrade filter will have regulatory valves for stopping effluent flow during backwashing.

When head loss across the 2 stage multigrade filter increases to 0.7 m, wastewater inflow to the filter will be closed and the sludge accumulated in the bottom hopper and in the graded gravel bed will be removed through backwashing the bed and draining out the water into the domestic wastewater pit.

Constructed wetland system (CWS)

The constructed wetland system will be of 200 m length, 2 m width and 0.4 m depth plus 0.2 m freeboard. The system will have a brick retaining walls on sides. The system will include a 4 m long non-vegetated inlet section, a 94 m long vegetated middle section and a 2 m long non-vegetated outlet section.

The inlet section will have 0.4 thick layer of 13-25 mm size gravel. The treated effluent inlet pipe will be submerged in the gravel layer and the treated effluent will come out into the CWS through a perforated pipe.

The vegetated section will have a bottom 150 mm thick layer of 13-25 mm size gravel, a middle 150 mm thick layer of <13 mm size gravel and a top 100 mm thick layer of sand (preferably coarse sand). Two rows of reeds (Phragmitis sp.) will be planted at 1 m spacing in the middle gravel layer in this section.

The non-vegetated outlet section will be having 0.4 m thick layer of <13 mm size gravel. A perforated pipe submerged in the gravel layer within the top 300 mm depth will be used to collect and convey the treated effluent into the treated effluent sump.

Please see figure-5 for details on the CWS.

Significant portion of the treated effluent will be lost through evapo-transpiration and through percolation into the underground. Annually once harvesting removal of the reed biomass may be needed. The harvested biomass has economic value and can even be sold out.

Treated effluent sump

A tank of 2 m length, 2 m width and 2 m liquid depth will be used as the treated effluent sump. Treated effluent from the CWS will be allowed to overflow into this sump under gravity. A overflow drain will be provided for this sump for allowing overflow of the excess treated effluent into the storm water drain of the industrial unit. Depending on the need the treated effluent will be pumped and disposed off within the industrial units premises through irrigation of the lawns, hedges and ornamental plants and the green belt plantation. If any of the treated effluent is left unutilized, specially during the rainy season, that will be allowed to overflow into the storm water drain for disposal.

Sludge thickening and stabilization pitSludge drained out from the anaerobic filter and from the 2 stage baffled anaerobic reactor and sludge wasted from the ASP will be collected into this sludge thickening and stabilization pit. This pit will be of 6 m length, 2.5 m width and 3.0 m depth and a freeboard of 0.3 m. It will have both vertical and inclined baffles for facilitating overflow of supernatant without disturbing the settled sludge and the floating scum. The outlet will have a flow regulating valve. Please see figure-6 for details. The clear supernatant separated will be allowed to return into the domestic

wastewater pit for further treatment and disposal along with the domestic wastewater. Sludge of the pit will be allowed to get thicken and stabilize within. For facilitating the thickening process diffused air will be supplied. Once in 6 months, sludge from the pit will be dredged out disposed off through using as soil conditioner in the green belt plantation.

Diffused aeration systems (3 numbers)

A single diffused aeration system will be used to supply air to both the ASP and the sludge thickening and stabilization pit. This system will include three route blowers (each of 50 Nm3/hour capacity and delivery pressure of 0.6 kg/cm2), two in operation and one standby, 18 diffusers (each with about 5 Nm3/hour air delivering capacity) and necessary piping and fittings. The diffusers will be fixed at about 300 mm height from the bottom of the tank. ASP will have 8 fine bubble disc diffusers (of silicon membrane) provided on a rectangular air main located at 0.5 m distance from the sides at the bottom. The sludge thickening and stabilization pit will have 10 diffusers (coarse bubble non-porous orifice type) in two rows of 5 each at 1.0 m spacing. No diffusers will be placed in the last 1.5 m length at the outlet end of the pit.

Hydraulic design of the ETP

Maximum water level in the detoxification tank, ground level of the industrial unit at the location of CWS (constructed wetland system) and invert level of the sewer conveying sewage to the ETP have been used as reference levels in the hydraulic design. Maximum water level in the detoxification tank has been taken

as –X m below/from the ground level, invert level of the incoming sewer to the ETP as –Y m from the ground level, and ground level at the CWS as 0.000 m were considered in the hydraulic design.

The Baffled anaerobic reactor, the upflow anaerobic filter, the ASP and the 2-stage multigrade filter all will be accommodated in a single civil structure of the following dimensions:

Width: 4 m (excluding the walls): in case of the 2-stage baffled anaerobic reactor and the 2-stage multigrade filter the width includes includes the dividing wall thickness.

Length: 11.5 m (excluding the walls) Depth: 4.8 m (in case of the 2-stage multi grade filter height can be reduced to 4.3 m from the

top)

Overflow of filtered water from the 2nd stage of the multigrade filter should be at least 0.5 m above the ground level.

The dechlorination tank can be an integral part of the detoxification tank and liquid depth in it will be at least 0.3 m below that of the detoxification tank.

The domestic wastewater pit can have 1.5 m liquid depth and its freeboard will be atleast 0.2 m greater than the depth to the invert level of the sewer conveying domestic wastewater to the ETP.

ETP for pharma formulation unit

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