BS EN 16087-1 pdf free download

BS EN 16087-1 pdf free download.Soil improvers and growing media- Determination of the aerobic biological activity.
Place the calculated quantity of the sample in the clean reaction vessel (see SA). Add 180 ml water (see f1) and 10 ml complete nutrient solution (see 65) using a dispenser (see 58). Add 10 ml p11 buffer (see 6.2) using a dispenser (see 5.8). Add 2,5 ml nitrification inhibitor (see 6.6) using a dispenser (see 5.8). Place the sample on the mixing device (see 5.5) and start the mixing for 4 h to 8 h in the conditioned room (see 5JJ. Do not close the bottles.
The nitrification inhibitor is added to prevent the use of oxygen for nitrification processes.
Then measure the p11 of the suspension. The value should be between 6,5 and 745. If this is not the case, base or acid should be added (see 68 and 1i.9).
The analyses shall be performed at least in duplicate.
At first instance, an equivalent of 2 g organic matter should be used for analysis. Ii it appears during the test that the pressure drop during the first three days is not higher than 2 kPa, then the amount of organic matter should be increased but with a maximum of 20 g dry matter. If on the other hand the pressure drop during the first three days is more than 5 kPa, the amount of organic matter should be adjusted to I g.
NOTE If it appears there is not enough material available, the complete test can he repeated with new material.
7.4 Respiration measurement
Fill the C02-absorbent containing unit (see 5.3) with the absorbent (see 6.7). The pellets can be used several times. Before every use, they shall be inspected for colour changes. If the colour has changed, they shall be replaced. Replace the bottle top sensor and ensure a gas-tight fit.
Start the shaking table (120 ± 20) rpm or magnetic stirrer (between 180 rpm and 450 rpm) and measure the pressure over seven days. Record the pressure 2 to 4 times per hour over seven days with the connected pressure transducer (see 52). The measurement ends, in principle, after seven days but can be ended if the pressure difference between the maximum and minimum value is more than 10 kPa.
NOTE If a magnetic stirrer is used and the amount of sand and gravel in the sample is high, it is important to check that the stirrer is not in contact with the base.
To check the tightness of the measurement system, it is necessary to include a blank measurement without sample material, but all necessary solutions.
8 Calculations
8.1 Theoretical background
The pressure drop as a function of time in principle looks like Figure 8.3. During the first period (0 h to 8 h), the pressure rises by the rising pressure of water vapour in the head space. Thereafter is a short period (0 h to 12 h) in which the pressure is more or less stable. This is the growing phase of microorganisms and is dependent on the number of active microorganisms initially present. In the third period, the pressure drops linearly and in the fourth phase the pressure drop decreases to become constant. In the final phase, the oxygen runs out. BS EN 16087-1 pdf download.