The Waste Pickling Liquor (WPL) generated in the galvanizing industries is a hazardous waste (Cat.12.2) as per the Hazardous and Other Waste (Management and Transbounary Movement) Rules, 2016 (HW Rules 2016). Hazardous and Other Wastes in the country are required to be managed as per the methods, technologies and Standard Operating Procedures (SOPs) notified by the Govt of India under these Rules. These Rules also provide scope for utilization of the wastes generated from one source in various other applications. The interested users of the hazardous and other wastes are required to obtain permission from the Central Pollution Control Board (CPCB) for this purpose. The grant of permission by CPCB involves conducting of trial runs to study and confirm the environmentally safe use of the intended waste in the proposed activity. In case of the use is found to be environmentally safe, CPCB prepares the SOP for the use and grants permission on a case to case basis. There has not been any application made so far for obtaining such permission for the use of the spent acid that is generated in galvanizing industries. Also, the cheap and easy availability of the hydrochloric Acid (HCl) in the country does not leave much scope for a viable recovery of the virgin HCl from WPL. The galvanizing industries therefore have a limited option of treating the WPL in their premises. The treatment of WPL by lime is an effective and widely practiced method. However, the lime treatment of the WPL leaves a very high concentration of the Total Dissolved Solids (TDS) in the treated waste water. The installation of RO/MEE systems at the industry level does not seem to be viable. Solar evaporation system also requires lot of open to sky area in the industry. The treated effluent with high TDS can be either discharged as such in coastal areas or to be treated at a common facility. However, there is lot of scope for the segregation of the spent HCl and its use in other industries/activities after obtaining the required permission from the CPCB. The segregation of the spent HCl also eliminates the problem of TDS in the waste water resulting from the treatment of the rest of the WPL. The galvanizing industry therefore needs to explore the possible uses of the spent HCl in other industrial activities and obtain permissions from CPCB for such uses instead of allowing to it to become part of the WPL. The presentation gives details of the relevant provisions of the HW Rules 2016, the status of the SOPs prepared so far by the CPCB, the limitations of acid recovery from the WPL and the recommendations for an environmentally sound management of the WPL.

1. Environmentally Sound Management of
Waste Pickling Liquor
By
Dr R S Mahwar, Environmental Adviser, ILZDA
Former Additional Director, Central Pollution Control Board
(Ministry of Environment, Forest & Climate Change), Govt. of India, Delhi
India Lead Zinc Development Association
(ILZDA) Seminar
on
GALVANIZING
May 5-6, 2017, Nagpur

2. Environmentally Sound Management of Waste
Pickling Liquor
 Environmentally Sound Management of Industrial Wastes in
India ?
 Management as per the provisions of the Hazardous and
Other Wastes (Management and Transboundary Movement)
Rules, 2016 (HW Rules 2016) notified by the Govt. of India on
April 4, 2016
 The Hazardous Wastes (Management, Handling and
Transboundary Movement) Rules, 2008 (HW Rules 2008)
stand repealed.

3. Waste Pickling Liquor Management and the HW
Rules 2016
 Waste Pickling Liquor: The entire liquid stream from the
Pickling process including the spent acid.
 Pickling Liquor/Spent Acid Classification as per the HW Rules
2016 : Hazardous Waste
• Schedule – I, Process S.No 12 : Metal surface treatment, such
as etching, staining, polishing, galvanizing, cleaning,
degreasing, plating, etc.
• Category 12.2: Spent acid and alkali

4. Definitions - Section 3(1)
(*Most relevant to the Waste Pickling Liquor)
 13. Environmentally Sound Management of Hazardous and
Other Wastes”
Means taking all steps required to ensure that the hazardous
and other wastes are managed in a manner which shall
protect health and the environment against the adverse
effects which may result from such waste;
 14. Environmentally Sound Technologies
Mean any technology approved by the Central Government
from time to time.

5. Definitions - Section 3(1)
 31. Storage
Means storing any hazardous or other waste for a temporary
period, at the end of which such waste is processed or
disposed of;
 35. Treatment
Means a method, technique or process, designed to modify
the physical, chemical or biological characteristics or
composition of any hazardous or other waste so as to reduce
its potential to cause harm.
 37. Utilisation
Means use of hazardous or other waste as a resource;

6. Grant of authorisation for Managing Hazardous and
Other Wastes – Section 6(1)(c)
 (i) Any person authorised under the provisions of the HW
Rules 2008 prior to the date of commencement of these rules,
shall not be required to make an application for authorisation
till the period of expiry of such authorisation;
(Relates to the existing permitted practices of waste disposal)
 (ii) any person engaged in recycling or reprocessing of the
hazardous waste specified in Schedule IV and having
registration under the provisions of the HW Rules 2008, shall
not be required to make an application for authorisation till
the period of expiry of such registration.
(Relates to the sale of Zinc Dross, Zinc Skimmings and zinc
Ash)

7. Utilisation of hazardous and Other wastes – Section 9
 (1) The utilisation of hazardous and other wastes as a
resource or after pre-processing either for co-processing or
for any other use, including within the premises* of the
generator (if it is not part of process), shall be carried out only
after obtaining authorisation from the State Pollution Control
Board in respect of the wastes on the basis of standard
operating procedures or guidelines provided by the Central
Pollution Control Board.
(* Means even a captive facility requires permission)
 (2) Where standard operating procedures or guidelines are
not available for specific utilisation, the approval has to be
sought from Central Pollution Control Board which shall be
granting approval on the basis of trial runs and thereafter,
standard operating procedures or guidelines shall be prepared
by Central Pollution Control Board.

8. Utilisation of hazardous and Other wastes – Section 9
 Provided, if trial run has been conducted for particular waste
with respect to particular utilisation and compliance to the
environmental standards has been demonstrated,
authorisation may be granted by the State Pollution Control
Board with respect to the same waste and utilisation, without
need of separate trial run by Central Pollution Control Board
and such cases of successful trial run, Central Pollution
Control Board shall intimate all the State Pollution Control
Board regarding the same.
(In case the spent acid from the galvanizing industry has
been in use for specific industrial applications in an
environmentally sound manner, the SPCBs can use this
clause to grant authorizations after conformation with CPCB)

9. Standard Operating Procedures or Guidelines for actual
Users of Hazardous and Other Wastes – Section 10
 The Ministry of Environment, Forest and Climate Change or
the Central Pollution Control Board may issue guidelines or
standard operating procedures (SOPs) for environmentally
sound management of hazardous and other wastes from time
to time.
 CPCB has published the documents
 Standard Operating Procedures and Checklist of Minimal
Requisite Facilities for utilization of hazardous wastes
<http://www.cpcb.nic.in/SoPs_for_utilisation_of_HW_July201
6.pdf>
 Processing of the proposals
<http://www.cpcb.nic.in/SOP_Rule_9_Dec_2016.pdf>

10. SOPs Prepared by CPCB for Use of the Spent Acid
Generated from Different Industrial Activities
 Utilization of Spent H2SO4 generated form Pickling of MS
Rods/Sheets for manufacturing Ferrous Sulphate. (Use of
Ferrous Sulphate in water purification not permitted) .
 Utilization of Spent HCl generated form steel rolling mills for
producing Ferric Chloride. (Use of Ferric Chloride in water
purification and agricultural applications not permitted)
 Utilization of Spent Acid (H2SO4 & HNO3 mixture) containing
Molybdenum generated from filament industries for
producing Molybdenum Trioxide by heating process.

11. Management of Waste Pickling Liquor (WPL) in
Galvanizing Industry – Possible Options
 The Waste Pickling Liquor Management- Primarily the
problem of managing the spent pickling acid.
 Possible Options
• Acid Purification/recovery and reuse on site
• Acid Purification/Recovery at a common facility
• Management/Disposal of WPL on site
• Utilization of the spent acid by other industries

12. Viability of the Spent Acid Purification/Recovery
and Reuse on Site
 Easy and cheap availability of the virgin Hydrochloric Acid
(Strength about 33%) in India.
 Virgin Hydrochloric Acid is a by-product of Caustic Soda
Industry.
 Application virgin HCl in galvanizing industry -already a reuse.

13. Viability of the Spent Acid Purification/Recovery
and Reuse on Site (contd.)
 Spent acid Purification/Recovery of virgin acid on site
requires:
• Proper segregation of the pickling bath discharges from other
liquid waste streams to prevent the impurities getting into the
acid
• Purchase of Virgin acid is still required though in reduced
quantities.
• Savings due to reduction in the disposal costs and reduced
virgin acid purchases are not expected to be more than the
overall costs involved in meeting the demand through
purchase of the virgin acid.

14. Viability of the Spent Acid Purification/Recovery
and Reuse on Site (Contd.)
• Distillation of the spent acid (just 5% w/w):
 Energy intensive
 High O/M costs including the O/M of the ECS/APCS.
 The residue Iron Oxide is unfit for the other applications as it
contains high concentration of heavy metals.

15. Viability of the Acid Purification/Recovery at a
Common Facility
 Involvement of all issues stated in respect of the on site
purification/recovery of the spent acid.
 Hazards/risks involved in the collection of the spent acid from the
individual industries and its transportation to the common facility
and supply of the recovered acid back to the industries ?
 Quality of the spent acid/recovered acid ?
 Disposal of the Iron Oxide Containing high levels of heavy Metals ?
 Landing cost of the recovered acid compared to the fresh acid ?
 The Establishment of a common facility –Requires Environmental
Clearance as per the EIA notification 2006
(Common facilities for the treatment of waste liquid streams are
encouraged only for the industries located in clusters/specific
industrial areas)

16. Management/Disposal of the Waste Pickling
Liquor on Site
 Preparation of a protocol by each industry for the
Environmentally Sound Management of the Waste
Pickling Liquor (WPL) at its own level.
 Fixing the Objectives
• Treatment of the WPL ?
• Sale/Giving of the Spent Pickling Acid (SPA) to other
industries and treatment of rest of waste water in
ETP ?

17. Treatment of the Waste Pickling Liquor
 Step -1:
Ensure following of the BMPs in regard to minimization of the
generation of waste water
Best Management Practices & Environmental Regulations for
Galvanizing Industry in India
<https://www.slideshare.net/rsmahwar1/best-management-practices-
environmental-regulations-for-galvanizing-industry-in-india>
 Step -2: (Optional..?)
Add a pre-calculated quantity of iron oxide to the spent
pickling acid before the latter becomes part of the WPL.

18. Treatment of the Waste Pickling Liquor
 Step-3:
• Treat the WPL with lime in a way that the mixture has a pH of
9 along with aeration to enable conversion of Ferrous into
ferric and precipitation as Ferric Hydroxide.
• Ferrous Hydroxide is very sticky and difficult to handle. The
appearance of greenish blue colour in the lime dosing tank
indicates precipitation of ferrous hydroxide.
 Step-4:
Filter the mixture into filter press to get the cake and filtrate.

19. Treatment of the Waste Pickling Liquor
 Step- 5:
• Disposal of the Filter cake
 The cake falls in the category 35.3 – “Chemical sludge from
waste water treatment ” as per Schedule-I of the HW Rules
2016
 Send the cake to TSDF or to the cement plants as per the
conditions of the authorization
 Get the Toxicity Characteristic Leaching Procedure (TCLP) or
Soluble Threshold Limit Concentration (STLC) tests done for
the cake as per Schedule –II of the HW Rules 2016.
 In case the waste passes the TCLP and STLC tests apply to
MoEFCC seeking exemption of the wastes from being
classified as Hazardous.
 Initiation of the action for seeking exemption from MoEFCC is
better if taken at the Association level.

20. Treatment of the Waste Pickling Liquor
 Step- 6 :
• Disposal of the Filtrate
 Filtrate Contains very High TDS
 Direct discharge into marine coastal areas in case of no limit
of TDS prescribed in the consent.
 Solar/forced evaporation or RO treatment in the premises.
 The treatment for TDS at the industry level is not expected to
be viable except for solar evaporation which also needs a
large open to sky area and also much less effective in the
rainy season.
 A common RO or MEE facility for TDS is more viable and
effective

21. Treatment of the Waste Pickling Liquor
 Transportation of the filterate to CETP.
 The treatment of high TDS at a common facility is much better
as the treated waste water with only high TDS does not
involve hazards in its transportation.
 Step-7:
• Disposal of the Evaporation residue (Evaporation in Industry)
 Get the TCLP and STLC tests done for the residue.
 Dispose as non hazardous waste in case it passes the tests
 Dispose as per the authorization in case it does not pass the
tests.

22. Utilization of the Spent Pickling Acid (SPA) in other
Industries
 Step -1:
• Obtain data on the average quality of the spent HCl generated
from the steel rolling mills and keep that as a reference for
maintaining the quality of the Spent HCl generated in
Galvanizing.
 The quality of the spent HCl generation from the Galvanizing
industry is expected to be inferior compared to steel rolling
mills.
 SOP for Utilization of Spent HCl generated form steel rolling
mills for producing Ferric Chloride already published by CPCB .
Use of Ferric Chloride in water purification and agricultural
applications not permitted.

23. Utilization of the Spent Pickling Acid in other
Industries
 Step-2:
• Make arrangements for the separate collection of the spent
pickling HCl in way that the other liquid streams are not
allowed to mix with it.
 Step-3:
• Identify the broad range of the industrial applications of the
spent HCl generated from the Galvanizing industry.
 Action needs discussions at the Association level, survey and
input of experts.

24. Utilization of the Spent Pickling Acid (SPA) in
other Industries
 Step-4:
• Make an application under Rule 9 of the HW Rules 2016 to
CPCB for obtaining the permission.
 This will involve conducting of the trial runs by the user
industries as per the SOPs/Protocol of CPCB.
• CPCB’s permission expected only if the findings of the trial
runs confirm environmentally safe use of the Spent HCl.
 Step-5:
• Obtain Authorization from the SPCB to sale the Spent HCl for
the uses specified in the permission of CPCB.

25. Conclusions and Recommendations
 The Environmentally Sound Management of Hazardous
Wastes in India is governed by the methods, technologies and
Standard Operating Procedures notified under the HW Rules
2016.
 The cheap and easy availability of the virgin Hydrochloric Acid
in India does not leave much scope for considering recovery
of the spent acid from the Waste Pickling Liquor and reuse at
site.
 The disposal of the WPL in the industry’s own premises
appears to be most viable and environmentally sound option.

26. Conclusions and Recommendations (contd.)
 The problems of TDS in the treated waste water could be
better managed at a common facility.
 There is scope for utilization of the Spent Hydrochloric Acid in
other industrial applications which should be identified and
permissions obtained from CPCB.
 The segregation of the Spent Hydrochloric Acid at source and
use in other industrial applications will also eliminate the
problem of TDS in the treated waste waters from galvanizing
industries.