STEPS SO FOR TAKEN AND THEIR IMPACTS

As a result of initiatives taken in recent years which have been reinforced through the Environmental Pollution Control Authority and directions of the Hon’ble Supreme court, the impacts in terms of pollution reduction as confirmed by CPCB findings include the following:

        (I) Unleaded Petrol

With the progressive reduction of lead content in petrol (from 0.56 gm./litre to 0.15 gm./litre), introduction of unleaded petrol for new passenger cars from April, 1995 and supply of only unleaded petrol for all vehicles from September, 1998, in UT of Delhi a lethal pollutant from vehicular exhaust has been removed. The lead content in the atmosphere near traffic intersections of UT of Delhi has reduced by more than 60% with the introduction of unleaded petrol. The apprehensions that the unleaded petrol would adversely affect the performance of engines and increase the emission of benzene have also been allayed. The refineries have been asked to ensure that the benzene content in unleaded petrol is not increased beyond the limit of 5% (v/v) as prescribed for the leaded petrol in 1996 and 3% (v/v) from 2000. However, the ambient air quality monitoring data indicate high levels of benzene and polyaromatic hydrocarbons before and after introduction of unleaded petrol. Hence, in addition to phasing out of lead it is necessary to reduce the benzene (to 1% or lower) and aromatics in petrol not only for Delhi but also for other parts of the country.

  (II) Sulphur in 
         Diesel 

Sulphur content in diesel supplied in Delhi was reduced to 0.5% in 1996 and it was further reduced to 0.25% in 1997. It is expected that diesel with 0.25% sulphur will be - available throughout the country by September, 1999. Considering the fact that several countries have introduced diesel with much lower sulphur content and it is necessary to have low sulphur diesel for meeting the emission norms beyond EURO-II norms (for EURO-I to EURO-II norms, sulphur content in diesel is 0.3%), the refineries will need to take steps for bringing down the sulphur content. 

SULPHUR IN DIESEL

Diesel emissions contain sulphur in particulate and gaseous form, and thus any reduction in sulphur has dual advantages. Recent evaluations carried out in Europe show the benefits of reduced sulphur in diesel fuel for lowering particulates. For example, preliminary data released from the Auto/Oil study showed that lowering the diesel fuel sulphur level from 2000 particles per million (ppm) 500 ppm reduced overall particulate from light-duty diesels by 2.4 percent, and from heavy-duty diesels by 13 percent. The relationship between particulates and sulphur level was found to be linear; for every 100 ppm reduction in sulphur, there is a 0.16 percent reduction in particulate from light-duty vehicles and a 0.87 percent reduction from heavy-duty vehicles. 

Options to Reduce the Sulphur Content of Diesel Fuel

    • In the crude state, increase the proportion of low-sulphur crude oil. 
    • Reduce the cut point of diesel fractions from both primary distillation as well as from the fractionation of secondary processing streams to 350-360oC. 
    • Improve fractionation efficiency to eliminate inter-stream overlaps during fractionation of diesel oils. 
    • Hydro-treat straight-sun diesel and thermally cracked diesel and/or hydrofine; reduce proportions of FCC oil blended into final product diesel oil. 
    • Install hydrocrackers that would enable production of very low-sulphur saturated diesel with high cetane numbers. 
 
  • GASOLINE LEAD PHASE OUT PROGRAMME IN INDIA
    Phase – IJune 1994Lowleaded
    (0.15 g/l)
    Cities of Delhi, Mumbai, Calcutta and Chennai 
    Phase – II 1.4.1995Unleaded (0.013 g/l)
    (+ low leaded)
    Cities of Delhi, Mumbai, Calcutta and Chennai 
    Phase – III 1.1.1997Lowleaded (0.15 g/l) Entire country
    Phase – IV1.9.1998Ban on Leaded fuel (Only unleaded fuel)NCT Delhi
    Phase – V 31.12.1998(Advanced to 1.9.98)Unleaded (0.013 g/l)
     (+ low leaded)
    All other capitals of States / UTs and other major cities.
    Phase - VI1.1.99Unleaded only 
    (0.013 g/l) 
    NCR
    Phase – VII 1.4.2000Unleaded (0.013 g/l)
    (+ low leaded)
    Entire country
    DIESEL SULPHUR PHASE OUT ROGRAMME IN INDIA
    Phase IApril 96Low Sulphur  (0.5%)Four metros and Taj Trapezium
    Phase IIAugust 97Low Sulphur (0.25%)Delhi and Taj Trapezium
    Phase IIIApril 98Low Sulphur  (0.25%)Metro Cities 
    Phase IVApril 99Low Sulphur  (0.25%)Entire Country

    (III) Tightening of vehicular emission norms

    During 1990-91, for the first time, mass emission norms for vehicles at manufacturing stage as well as for in-use vehicles have been notified. For meeting these norms, the manufacturers did not require any major modifications. The emission norms along with fuel quality specifications laid down in 1996 required the automobile manufacturers to make modification in the engine design particularly in regard to crankcase emission and evaporative emission control. From April, 1995 new passenger cars were allowed to register only if these were fitted with catalytic converters. Emission norms for such cars were tightened by 50 percent as compared to 1996 norms. The testing method for Passenger Cars norms was changed to cold start from hot start from April 98 which is a stricter procedure than the previous one. The norms for the year 2000 notified in August 1997 under the Motor Vehicle Rules require major modifications in the engine design specially in regard to fuel injection system in passenger cars and fitment of catalytic converters in 2 stroke engines. These standards are akin to EURO-I norms adopted in the European countries in 1992. With the recent directions of the Hon’ble Supreme Court, passenger cars (both petrol and diesel) are required to meet atleast EURO-I norms June 1999 and from April 2000 only such vehicles meeting EURO-II norms will be registered in the National Capital region. CNG operated vehicles are also permitted by the Supreme Court directions.

    (IV) 2-T oil for 2 stroke engines

    On the recommendation of CPCB, the Ministry of Environment & Forests notified the specifications for 2T oil which became effective from 01.04.99. The specifications required use of low smoke 2T oil which is one of the causes of pollution from 2 stroke engines. To prevent the use of 2T oil in excess of the required quantity, pre-mixed 2T oil dispensers have been installed in all the petrol filling stations of Delhi. Sale of loose 2T oil has also been banned from December, 1998.

    POLLUTION REDUCTION THROUGH PREMIX 2T OIL DISPENSER
    The two stroke two and three wheelers require 2 T oil for lubrication of engine. The lubrication is carried out either through premixing modes or through oil injection modes. In either case it is a total loss system as the oil is burnt along with the fuel and goes through the exhaust. The burnt oil comes out through the exhaust, which is responsible for smoke and particulate matter emission.The burning quality of mineral based lubricating oil is very poor as compared to that of petrol. Major fraction of the lubricating oil entering the engine may therefore burn only partially or remain unburned. Some of the burnt oil may lead to formation of solid particles while major fraction may remain unburnt. This reflects itself as visible smoke in the exhaust in the form of oil droplets and some solid particles. The totality of these solid particles is referred to as particulate matter.The two stroke vehicles required 2 T oil at concentration not more than 2% i.e. 20 ml in a litre of petrol. There is tendency to mix excess oil in petrol keeping disbelief in mind that more lube oil increase engine life.Excess use of 2 T oil causes following problems :
    1. Increases visible smoke and particulate matters. It has been found that with increase of 1% of oil there is increase of about 15% of particulate matter.
    1. Oil consumption is more.
    2. More engines deposit.
    3. Reduction in life of spark plug and engine.
    (V) Phasing out of grossly polluting vehicles To begin with, 20-year old vehicles were prohibited from plying from December 1998, followed by phasing out of 17-year old vehicles from November 98 and 15-year old vehicles from December 1998. Registration of new auto-rickshaws with front engine has been banned from May 1996 and the registration of old defence service and govt. auctioned vehicles has been banned from April, 1998.(VI) Impacts on pollution load and air quality The steps taken so far taken had some impact on vehicular pollution load and air quality. The major impacts have been observed through implementation of emission norms and fuel quality specifications effective from 1996, as also phasing out of 15-year old commercial vehicles and leaded petrol in the year 1998. Table 1 shows estimated vehicular pollution load in different years if no measures were taken and with various measures taken. Due to increase in growth of vehicles, the vehicular pollution load has increased from 1990-91 to 1995-96. With the implementation of emission norms and fuel quality specifications, phasing out of 15-year old vehicles and leaded gasoline the pollution load has decreased in 1998-99. The ambient air quality monitored in different areas of Delhi also shows a similar trend (Table 2). As compared to 1995, the levels of pollutants in the ambient air of Delhi has decreased by 4-40 percent in case of SO2, 4-13 percent in case of NO2, 6-17 percent in case of Particulate Matter, 3 percent in case of Carbon monoxide and 11 to 60 percent in case of lead during 1998.

    Table 1 Estimated Vehicular Pollution Load in Delhi
    Pollutants
    Pollution Load in thousand tonnes
    % reduction as compared to 1995-96
    Without measures
    With measures
    1990-91
    1995-96
    1998-99
    1995-96
    1998-99
    Carbon monoxide
    243
    373
    451
    351
    337
    4
    Hydrocarbons
    82
    123
    148
    113
    115
    +2
    Nitrogen Oxides
    139
    208
    248
    207
    182
    12
    Sulphur dioxide
    10
    15
    17
    15
    11
    27
    Lead
    0.190
    0.259
    0.362
    0.259
    0.007
    97
    Particulate Matter
    19
    28
    33
    28
    21
    25
    Total Pollution Load
    394
    747
    897
    714
    666
     
    Emission Load in t/day
    1351
    2047
    2459
    1957
    1825
     

    Table 2 Estimated Vehicular Emission load in Delhi

    Pollutants
    Pollution load in thousand tonnes
    1990-911995-961998-99% reduction as compared to 1995-96
    Sulphur dioxide10151127
    Nitrogen dioxide13920718212
    Particulate Matter19282125
    Lead0.1900.3620.00797
    Carbon Monoxide2433513374
    Hydrocarbons0.83113115+2

    Table 3 Ambient air quality in Delhi

     
    1995
    1998
    Percent reduction as compared to 1995
    INDUSTRIAL AREA
       
    Sulphur dioxide
    24.1
    20.2
    16
    Nitrogen dioxide
    35.5
    34.7
    4
    Suspended Particulate Matter
    420
    367
    13
    Lead
    110
    105
    5
    RESIDENTIAL AREA
       
    Sulphur dioxide
    16.5
    15.8
    4
    Nitrogen dioxide
    32.5
    28.6
    13
    Suspended Particulate Matter
    409
    341
    17
    Lead
    155
    95
    39
    TRAFFIC INTERSECTIONS
       
    Sulphur dioxide
    42
    25
    40
    Nitrogen dioxide
    66
    63
    5
    Suspended Particulate Matter
    452
    426
    6
    Lead
    335
    136
    60
    Carbon Monoxide
    5587
    5450
    3
    all units are in microgramme/cubic metre except for lead which is in nanogramme/cubic metre.


    Table 4 National Ambient Air Quality Standards

    PollutantsTime-weighted average
    Concentration in ambient air
    Method of measurement
    Industrial AreasResidential, Rural & other AreasSensitive Areas
    Sulphur

    Dioxide (SO2)

    Annual Average*80 m g/m360 m g/m315 m g/m3- Improved West and Greake Method
    24 hours**120 m g/m380 m g/m330 m g/m3- Ultraviolet Fluorescence
    Oxides of Nitrogen as NO2Annual*80 m g/m360 m g/m315 m g/m3- Jacob & Hochheiser Modified (Na-Arsenite) Method
    24 hours**120 m g/m380 m g/m330 m g/m3- Gas Phase Chemiluminescence
    Suspended 

    Particulate Matter (SPM)

    Annual*360 m g/m3140 m g/m370 m g/m3- High Volume Sampling,
    24 hours**500 m g/m3200 m g/m3100 m g/m3(Average flow rate not less than 1.1 m3/minute).
    Respirable

    Particulate matter (RPM) (size less than 10 nm)

    Annual*120 m g/m360 m g/m350 m g/m3- Respirable particulate
    24 hours**150 m g/m3100 m g/m375 m g/m3matter sampler
    Lead (Pb)Annual*1.0 m g/m30.75 m g/m30.50 m g/m3- ASS Method after sampling using EPM 2000 or equivalent Filter paper
    24 hours**1.5 m g/m31.00 m g/m30.75 m g/m3 
    Carbon

    Monoxide (CO)

    8 hours**5.0 mg/ m32.0 mg/ m31.0 mg/ m3- Non dispersive infra end
    1 hour10.0 mg/ m34.0 mg/ m32.0 mg/ m3Spectroscopy
    * Annual Arithmetic mean of minimum 104 measurements in a year taken twice a week 24 hourly at uniform interval. ** 24 hourly/8 hourly values should be met 98% of the time in a year. However, 2% of the time, it may exceed but not on two consecutive days.

    NOTE: 1. National Ambient Air Quality Standard: The levels of air quality with an adequate margin of safety, to protect the public health,, vegetation and property. 2. Whenever and wherever two consecutive values exceeds the limit specified above forthe respective category, it would be considered adequate reason to institute regular/continuous monitoring and further investigations.

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