HELCOM RECOMMENDATION 16/7
Adopted 15 March 1995, having regard to Article 13, paragraph b) of the Helsinki Convention
BASIC PRINCIPLES IN WASTE WATER MANAGEMENT IN THE LEATHER INDUSTRY
THE COMMISSION,
RECALLING Article 5 of the Convention on the Protection of the Marine Environment of the Baltic Sea Area, 1974 (Helsinki Convention), in which the Contracting Parties undertake to counteract the introduction of certain hazardous substances, as specified in Annex I of the Convention, into the Baltic Sea Area,
RECALLING ALSO that according to Article 6 of the Helsinki Convention all appropriate measures to control and strictly limit pollution by noxious substances listed in Annex II of the Convention, shall be taken, and that according to Annex III of the Convention the pollution load of industrial wastes shall be minimized,
RECALLING FURTHER that the Ministerial Declaration of the ninth meeting of the Helsinki Commission calls for a considerable reduction of land-based pollution,
RECOGNIZING that the leather industry is responsible for a part of the discharges of hazardous substances, especially chromium, into the Baltic Sea,
RECOGNIZING ALSO that many leather industry plants discharge to municipal sewerage systems where HELCOM Recommendation 13/2 should be applied,
RECOMMENDS to the Governments of the Contracting Parties that they apply to leather industry plants discharging into water bodies or municipal sewerage systems, the following basic principles:
a)to reduce pollution loads from the leather industry Best Available Technologies as per examples listed in Appendix 1, should be selectively applied. It is essential to reduce the volume of waste water discharges through, i.a., a specific water consumption reduction to a maximum rate of 50 m3/t input hide;
b)waste water discharges into either water bodies or municipal sewerage systems should be treated using optional waste water treatment processes, examples of which are listed in Appendix 2;
c)the limit values for waste water discharges from the leather industry into water bodies or municipal sewerage systems should not exceed the following values:
Crtot -0.075 kg/t input hide as annual mean and 1.5 mg/l Cr as 24 h-value or shorter sampling period
CODCr -20 kg/t input hide as annual mean for discharges to water bodies and for discharges into sewerage systems which are not connected to municipal treatment plants
tot-N -8 kg /t input hide as annual mean for discharges to water bodies and for discharges into sewerage systems which are not connected to municipal treatment plants
Internationally accepted standardized sampling, analysing and quality assurance methods (e.g. CEN-standards, ISO-standards and OECD-Guidelines) should be used whenever available;
d)the tanning odour influence should be taken into account in siting of a new production unit as well as in a sludge dumping location,
RECOMMENDS ALSO that the above limit values should be implemented for production units newly constructed or reconstructed by 1 January 1996, and for existing units by 1 January 2000,
DECIDES that the above limit values be re-examined in 1998,
RECOMMENDS FURTHER that the Contracting Parties report to the Commission every three years starting in 1997.
Appendix 1
BEST AVAILABLE TECHNOLOGY
Examples of preventive technologies in leather industry reducing the amounts of pollutants
Examples of preventive Potential Manufacturing Reduction
technologies pollutants process
General good house Water consumption All wet Water consumption
keeping, short floats, general processes
modern tannery vessels,
spring valves, recycling
Hide chilling Salt Hide preserve No salt
Hair recovery High COD and BOD Unhairing Reduced COD
and BOD
Reduced sulphide unhairing Sulphide Unhairing Reduced sulphide
Low-lime unhairing Lime Unhairing Reduced SS (lime)
Ammonium free deliming Ammonium Deliming No use of ammonia
compounds bating Reduced BOD and N
Aqueous degreasing Solvents Degreasing No solvent
(effluent)
Improved chromium Chromium Chrome tanning Reduced chromium
exhaustion/fixation effluent
Chromium recovery/ Chromium Chrome tanning Reduced chromium
recycling effluent
Chromium replacement Chromium Chrome tanning Reduced or no chromium
partial or complete effluent and solid waste
Wet white pretanning Chromium Chrome tanning Reduced chromium
solid waste
Appendix 2
Examples of waste water treatment processes for leather industry
Examples of treatment Potential Reduction
processes pollutants
1. Pretreatment
Screening large fragments up to 30-40% of total SS
Settling COD up to 30%
Flow equalization neutralization agent and possibility
(balancing) of mutual precipitation in certain cases
2. Primary treatment
Catalytic oxidation or direct sulphides
precipitation of sulphides lower pH
Precipitation/Flocculation chromium up to 0.5 mg/l
Chromium
Physical-chemical treatment BOD up to 95% of SS around 70% of BOD
for BOD and solids removal SS
3. Secondary treatment
Biological treatment BOD
- biological filters COD
- activated sludge below 20 mg/l
(oxidation ditch) of BOD5 and
- activated sludge 250 mg/l of COD
(conventional)
- anaerobic process up to 85% of BOD5
(lagoons)
4. Tertiary treatment
Nitrification/denitrification N eutrophication reduction
Sedimentation/filtration SS up to 95% efficiency
REPORTING FORMAT ON HELCOM RECOMMENDATION 16/7 CONCERNING BASIC PRINCIPLES IN WASTE WATER MANAGEMENT IN THE LEATHER INDUSTRY
1.Country
2.Plant and location
3.Actual production (tonnes of input hides/a and/or m2/a)
4.Water consumption, sewage discharge and pollution loads
Water consumpton m3/a | Sewage dischaged into: municipal sewerage water bodies systems m3/a m3/a
| |
| Parameters | Load t/a Specific load (kg/t) or max Load t/a concentration for Crtot only | Specific load (kg/t) or max concentration (mg/l) for Crtot only |
| Crtot | ||
| CODCr *) | ||
| tot-N | ||
| *) For Contracting Parties who are measuring TOC the conversion factor should be indiccated | ||
5.Description of technological processes, chemicals in use, preventive and waste water treatment processes
6.Actions undertaken for reducing discharges in the last three years.