324
F. Hell and 1. Lahnsteiner
fraction in the raw water is 17%, whereas the fraction in the brine amounts to 37%
of total salt content.
Due to the relatively low sodium content of the raw water, the sodium
adsorption ratio [see Eq. (1)] is very low. Sodium damage of the crop is not to be
expected.
Sodium adsorption ratio (SAR) [Eq. (1)J
SAR = CNa [mEq]
~cca : CMg I
(1)
Even though magnesia is a vegetable nutrient, the magnesium fraction [see Eq.
(2)] should not exceed a value of 50 (Eberhard 1993).
Magnesium fraction [Eq. (2)]
CM
Mg fraction =
g
* 100 (eq%)
CMg +cCa
(2)
In general, the alkalinity of the groundwater is lower than the total hardness.
Hence, the value of the residual sodium carbonate (RSC) is negative and the water
is suitable for irrigation purposes.
To summarise, the brine is suitable for use in direct irrigation, at least for
chloride-tolerable plants. In reality, the brine is blended with other irrigation
waters. Thus, the water is suitable for irrigation for all kinds of plants.
After start up in August 1997, the plant was in operation for approximately 2
months, then mothballed during the winter and restarted in May 1998. After
seasonal operation in 1998 and 1999, in autumn 2000 the plant was kept in
operation. Nevertheless, the winter operation was as low as possible. The plant
was switched on only to avoid stagnation of the water in the system. This
procedure should be tested as an alternative to the preservation system.
Regarding operating costs, the calculated values could be confirmed by the
actual costs.
Considering an operating time of only 4 months and the maximum guaranteed
annual replacement of membranes and electrodes, the total operating costs amount
to 0.24 €m"3. The main part of the operating costs are related to membrane
replacement. Due to the automatic system, the local supervision could be
minimised and hence personal costs are low. The plant proved to be reliable and
easy to control via the remote control system.
F. Hell and 1. Lahnsteiner
fraction in the raw water is 17%, whereas the fraction in the brine amounts to 37%
of total salt content.
Due to the relatively low sodium content of the raw water, the sodium
adsorption ratio [see Eq. (1)] is very low. Sodium damage of the crop is not to be
expected.
Sodium adsorption ratio (SAR) [Eq. (1)J
SAR = CNa [mEq]
~cca : CMg I
(1)
Even though magnesia is a vegetable nutrient, the magnesium fraction [see Eq.
(2)] should not exceed a value of 50 (Eberhard 1993).
Magnesium fraction [Eq. (2)]
CM
Mg fraction =
g
* 100 (eq%)
CMg +cCa
(2)
In general, the alkalinity of the groundwater is lower than the total hardness.
Hence, the value of the residual sodium carbonate (RSC) is negative and the water
is suitable for irrigation purposes.
To summarise, the brine is suitable for use in direct irrigation, at least for
chloride-tolerable plants. In reality, the brine is blended with other irrigation
waters. Thus, the water is suitable for irrigation for all kinds of plants.
After start up in August 1997, the plant was in operation for approximately 2
months, then mothballed during the winter and restarted in May 1998. After
seasonal operation in 1998 and 1999, in autumn 2000 the plant was kept in
operation. Nevertheless, the winter operation was as low as possible. The plant
was switched on only to avoid stagnation of the water in the system. This
procedure should be tested as an alternative to the preservation system.
Regarding operating costs, the calculated values could be confirmed by the
actual costs.
Considering an operating time of only 4 months and the maximum guaranteed
annual replacement of membranes and electrodes, the total operating costs amount
to 0.24 €m"3. The main part of the operating costs are related to membrane
replacement. Due to the automatic system, the local supervision could be
minimised and hence personal costs are low. The plant proved to be reliable and
easy to control via the remote control system.