HJ 905-2017Technical specification for environmental monitoring of odor (English PDF)

4.1 Organized emission source sampling points

4.1.1 Sampling location

According to GB/T 16157 gas pollutants sampling method of the relevant requirements.

With a vacuum flask to collect foul gas samples, the sampling position should be selected at the exhaust pressure is positive pressure or atmospheric pressure at the point.

4.1.2 Sampling points

According to GB/T 16157 gas pollutants sampling method of the relevant requirements.

4.2 Unorganized source sampling points

4.2.1 Point layout

Follow HJ/T 55 in the relevant requirements.

Winds and wind speeds should be monitored during sampling of malodorous monitoring of unorganized emissions. Should be arranged in the downwind direction of the perimeter Monitoring point. Under normal circumstances, the point set up in the perimeter of the main wind direction of the downwind axis and wind direction change standard deviation ± S° range or within the stench orientation of the odor, as shown in Figure 1. ± S ° calculation and measurement method reference HJ/T 55, measured every minute Secondary wind angle, continuous determination of 10 times, whichever is the average and calculate the standard deviation range.

When the measured circumference unconditionally sets the monitoring point, the monitoring point can be set within the circumference. In principle, the distance from the circumference does not exceed 10 Meter. When the discharge source is close to the wall (perimeter of the unit) and the wind speed is less than 1.0m/s, additional monitoring points will be set up outside the wall.

When two or more units of unorganized emission sources are adjacent to each other, the unorganized emission sources to be tested shall be selected in the upwind direction when the concentration of odor monitoring, the distribution method with the former.

Rain, snow and the weather, due to pollutants will be absorbed, affecting the representativeness of the monitoring data should not be odorless organized emission monitoring.

Figure 1 under normal circumstances monitoring point settings diagram

4.2.2 The number of sampling points Generally set 3 points, according to changes in wind conditions may be appropriate to increase or decrease the monitoring point.

4.3 Ambient air sampling point

Site monitoring of malodor, spot investigation (pollution occurs at the time, place, etc.) way to determine the sampling point.

For monitoring of malodor in the water area, if the polluted water area is close to the shore, the side of the river is selected for monitoring when the wind direction is downwind, taking the shore as the perimeter.

4.4.1 Sampling frequency of organized emission sources

a) Continuous organized emission sources According to the production cycle to determine the sampling frequency, the number of samples collected not less than 3 times, whichever is the maximum measurement Value. Production cycle within 8h, the sampling interval of not less than 2h; production cycle is greater than 8h, the sampling interval of not less than 4h.

b) Intermittent organized sources should be sampled at the peak of the odorous pollution concentration, the number of samples collected is not less than 3 times, whichever is the maximum measured value.

4.4.2 Sampling frequency of unorganized emission sources

a) Continuous unorganized sources are collected every 2 hours and collected 4 times, whichever is the maximum.

b) Intermittent, unorganized sources should be sampled at the highest level of malodour contamination for a minimum of 3 samples, whichever is greater the maximum measured value.

4.4.3 Ambient air sampling frequency

For the monitoring of ambient air-sensitive spots, according to the site survey, the investigation identified the sampling period, the number of samples collected at least 3 times, whichever is the maximum measured value.

5.1 Sampling methods for organized sources

5.1.1 Vacuum bottle sampling

5.1.1.1 System components

Vacuum bottle sampling system consists of vacuum bottles, washing bottles, drying filters and suction pump and other components, shown in Figure 2.

1- three-way valve; 2- vacuum gauge; 3- drying filter; 4- vacuum bottle; 5- washing bottle; 6- suction pump

Figure 2 vacuum bottle sampling system

5.1.1.2 Sampling operation

a) After the dehumidification of the vacuum flask, evacuated to a negative pressure before sampling 1.0 × 105Pa. Observe and record the pressure in the vacuum bottle, Place for at least 2 hours, the vacuum bottle pressure changes can not exceed 20% of the specified negative pressure 1.0 × 105Pa, or can not be used to replace the vacuum bottle.

b) System air leak check. Connect the system as shown in Figure 2. Close the sampling tube outlet three-way valve, open the suction pump exhaust, so Vacuum pressure gauge negative pressure rose to 13kPa, close the suction pump side of the valve, such as the pressure drop within 1min does not exceed 0.15kPa, it is regarded as airtight system. If found to leak, to re-check, install, leak again to confirm the system can not leak before mining kind. Before sampling, turn on the suction pump to purge the air at 1L/min for about 5 minutes to replace the air in the sampling system.

c) Turn on the sampling line, open the vacuum flask cock and allow the gas to enter the vacuum flask, then close the cock and remove the vacuum flask.

d) Record the sampling conditions, ambient temperature, atmospheric pressure and pressure in the bottle before vacuum sampling if necessary.

Note 1. This system sampling can not be adopted when the pressure in the pipeline is negative, and the sampling position can be moved to the positive pressure after the fan.

Note 2. The vacuum bottle should be as close to the discharge pipe, and should be used inert pipe (such as Teflon tube, etc.) as the sampling tube.

Note 3. Wash bottles should be used when collecting strong acids or strong alkaline gases. Take 100ml washing bottle, containing washing liquid, such as gas to be measured the system is acidic, with 5mol/L sodium hydroxide solution to wash the gas, if alkaline is 3mol/L sulfuric acid solution to wash the gas.

5.1.2 Airbags sampling

5.1.2.1 System composition

Air bag sampling system consists of air bag sampling box, sampling bag, suction pump and other components, see Figure 3.

5.1.2.2 Sampling operation

a) Connect the components as shown in Figure 3.

b) System air leak check. Install a vacuum pressure gauge before the air pump, other operations are the same as the vacuum bottle sampling system, see this standard 5.1.1.2.

c) Open the valve between the sampling gas conduit and the sampling bag, start the suction pump, extract the sampling bag of the air bag into a negative pressure, Into the sampling bag, the sampling bag is full of gas, close the sampling bag valve.

d) Sampling according to the above operation, with the gas to be washed three times the sampling bag.

e) Sampling ends, remove the sample bag filled with sample gas from the air bag sampling box and return it to the laboratory.

f) Record the sampling conditions, ambient temperature and atmospheric pressure as necessary.

Note. When the exhaust temperature is high, pay attention to the applicable temperature of the air bag.

1-sampling bag; 2-air bag sampling box; 3-intake port; 4-exhaust port;

Figure 3 air bag sampling system

5.2 Unorganized sources and ambient air sampling method

5.2.1 Meteorological parameters monitoring

Under normal circumstances, the monitoring of meteorological parameters should include the measurement of ambient temperature, atmospheric pressure, prevailing wind direction and wind speed, and Sampling synchronization. When the wind direction changes, the deviation of wind direction standard deviation ± S ° obviously deviates, it is necessary to adjust the monitoring point in time.

5.2.2 Vacuum bottle sampling

5.2.2.1 Laboratory Preparation. After the dehumidification of the vacuum flask, evacuated to a negative pressure before sampling 1.0 × 105Pa. Observation and record the pressure in the vacuum flask, placed at least 2 hours, the vacuum bottle pressure changes can not exceed 20% of the specified negative pressure 1 × 105Pa, no You can not use, replace the vacuum bottle.

5.2.2.2 On-site sampling. Select the sampling location of malodorous unorganized emission source according to 4.2.1, and sample at the maximum time of malodour smell.

When sampling, open the air stop clip (or air inlet valve) of the air inlet hose of the vacuum bottle to fill the sample gas in the bottle to atmospheric pressure, then Seal with gas stop inlet.

5.2.2.3 fill in the sample records. including sampling date, start time, sample number, sampling location, ambient temperature, mining Sample before the vacuum bottle pressure, vacuum bottle capacity, sampling point schematic and odor sensory description of the state of odor.

5.2.3 Air bag sampling

5.2.3.1 Laboratory Preparation. Check that the sampling bag is intact.

5.2.3.2 Site Sampling. As shown in Figure 4, the sample bag after emptying should be installed in the air bag sampling box. According to 4.2.1 choose evil Smell unorganized emission source sampling position, to smell the odor during the maximum sampling period. Open the intake check valve sampling, so evil Stink gas quickly filled with gas bag. Remove the sampling bag from the lid and send the collected samples back to the laboratory.

5.2.3.3 fill in the sampling records. including sampling date, start time, sample number, sampling location, ambient temperature, mining Sample bag capacity, sampling point schematic and sensory description of foul-smelling conditions.

1- intake stop valve; 2- negative pressure table; 3- suction shut-off valve; 4- sampling bag

Figure 4 air bag sampling box

6.1 Sample pre-treatment method

Samples can be prediluted when the concentration of the organized source sample is too high.

6.1.1 Vacuum bottle sample pre-dilution

The vacuum bottle after the sample into the laboratory to stand for half an hour to reach a temperature balance, and then pre-dilution treatment. Dilution operation is to connect the air bag at the air inlet of the vacuum bottle, inject the known volume of tasteless air or high-purity nitrogen gas from the large-end silicone rubber catheter, Forcing the gas in the vacuum bottle into the air bag, pushing the syringe repeatedly and injecting the air and the sample gas evenly to obtain the dilution factor Sample gas for K. The dilution K is calculated according to formula (1). Ensure gas and syringe airtight, the pipeline is not adsorbed.

Where. V1-- vacuum bottle collected sample gas volume, L;

V2 - injected air volume, L;

K - the dilution of the sample.

The actual concentration of the diluted sample is calculated according to equation (2).

C = C analysis × K (2) where. K-- dilution of the sample;

C Analysis - Analytical concentration of the sample, dimensionless;

C - the actual concentration of the sample, dimensionless.

6.1.2 Air bag samples pre-diluted

Airbags collected samples to the laboratory for half an hour to reach a temperature balance, and then pre-dilution treatment. Dilution operation is Use a syringe to extract a certain amount of sample gas V1, into another air bag, and then according to the analysis of the need to inject V2 volume Air or high purity nitrogen mixture, to obtain a diluted sample gas. The dilution K is calculated according to formula (1).

6.2 Odor analysis method

6.2.1 odor concentration analysis in accordance with GB/T 14675 related requirements.

6.2.2 Determination of emissions source odor concentration, the gas distributor first dilution test, the initial determination of the initial dilution factor. And then More suitable for sniffing personnel to carry out experimental dilution concentration for follow-up experiments.

6.2.3 Determination of environmental odor concentration, the results of the group average resolution of the M may have several results, the following provisions Analyze.

A. M1 The average dilution rate of the first average solution is less than 0.58, then stop the analysis, the sample odor concentration of less than 10.

B. M1 first dilution factor average solution rate is less than 1 and greater than 0.58, and then increase the dilution factor 10 times, obtained in paragraph the average dilution rate of the second dilution rate of M2, if M2 is less than 0.58 to stop the analysis, according to GB/T 14675 in the relevant formula Sample odor concentration.

C. If the average rate of the first dilution of M1 is less than 1 and greater than 0.58, the average of the second dilution Although the dissolution rate M2 is less than M1 but still greater than 0.58, then continue to 10 times the gradient dilution gas distribution until the final average rate of dissolution is less than 0.58, and calculate the odorous concentration results with the average rate of one adjacent immediate solution as M1. At this time t1 in the formula is adjacent to the thin Release multiple.

D. M1 is greater than 0.58. When M2 is greater than M1 after continuing the sample dilution, it indicates that people have a sense of smell of the gas Sensitivity is high, M1 gas concentration away from the olfactory threshold, should continue to increase the dilution factor until the average positive solution rate Mn small at Mn-1, and less than 0.58, the analysis was stopped.

8.1 Monitoring personnel requirements

8.1.1 Requirements of the supervisor

In accordance with GB/T 14675 in the relevant requirements.

8.1.2 Sniffing work requirements

In accordance with GB/T 14675 in the relevant requirements.

8.2 Sampling equipment preparation

8.2.1 Vacuum bottle

a) For odor concentration sampling, the sample should be used before the air purge, and then use the vacuum, the vacuum bottle after use should be Purge with air. When the use of the vacuum bottle after the more serious pollution, the method should be used boiling or potassium dichromate washing method Reason. For details, see Appendix A.1.3.

b) When the sample concentration of organized emission sources is too high and the sample needs to be pre-diluted, the vacuum bottle should be set before sampling Capacity, can be used to measure the volume of vacuum flask fixed volume, vacuum flask after volume should be dehumidified and then exhaust sampling. Fixed volume addition Wet method see Appendix A.1.4.

c) A leak test should be performed on newly purchased vacuum bottles or newly installed stoppers. Vacuum tight with a rubber stopper with a vacuum gauge Bottom of the big mouth, vacuum decompression to the absolute pressure 1.33kPa below, placed 1h, if the absolute pressure inside the bottle does not exceed 2.66 kPa, it is regarded as airtight.

8.2.2 Syringes

The newly purchased syringes should be leak tested. Wet the syringe stopper with water, inhale air to the mark 1/4, with a rubber cap blocked vent, repeatedly push the pull out of the plug a few times, such as the plug every time the position back to the original error Difference is not more than 2.5% of the original volume, can be regarded as airtight.

8.3 Sample Management

8.3.1 Identification of the sample

Sample should be prepared unique identification code, including the sample number, sampling time, sampling location,, frequency, monitoring project. The source sample should also indicate the information on the exhaust tube.

8.3.2 Sample Storage and Transportation

a) Samples should be sealed after sample collection. Samples of environmental samples and sources of contamination should be separated during transport and storage Set, and prevent odor pollution.

b) The sample stored in the vacuum bottle should have the corresponding box, to prevent light and collision, airbag samples should be stored in the dark.

c) All samples should be stored at 17 ~ 25 °C.

d) Samples for odor concentration analysis shall be determined within 24 h after sampling.

Appendix A.

(Informative)

Sampling equipment and auxiliary facilities A.1 vacuum bottle A.1.1 Vacuum bottle specifications Vacuum bottle structure shown in Figure A.1, according to its size, divided into large, medium and small three specifications, respectively, the capacity of about 10L, 3L, 1.5L. Vacuum bottle large mouth, sealed with a No. 2 silicone rubber stopper, the sealing plug with a vacuum gauge. Vacuum bottle inlet, a spherical interface, Seal with silicone rubber conduit and air-tight clip. After vacuuming the vacuum flask, the vacuum gauge on the sealant may be used to measure the vacuum pressure of the vacuum flask.

1- air inlet; 2- vacuum gauge; 3- air outlet

Figure A.1 vacuum bottle schematic

A.1.2 vacuum flask technical requirements Vacuum bottle made of borosilicate glass, should have 2kg/cm2 compression capacity.

A.1.3 vacuum bottle cleaning A.1.3.1 vacuum bottle air purge Vacuum bottle sampling can be used before the air purge, which uses a silicone rubber tube vacuum sampling bottle inlet end (small mouth) and suction pump inlet Take over the connection, open the vacuum flask large mouth rubber stopper, in the air environment, with the suction pump air extraction about 2min, so that the residual sample bottle the adsorbed odor material is volatilized and removed until it is confirmed that the sample bottle is odorless and ready for use.

A.1.3.2 vacuum bottle washing method If the vacuum bottle has stains to be cleaned, the same method of cleaning glassware, after cleaning using A.1.4 method of drying.

If the vacuum flask has obvious odor, such as the sample of the sample with higher odor concentration, when using the suction pump to purge the air is invalid, the the vacuum sampling bottle into the large steamer on the bottom of the boiling water boil 0.5h, dry naturally, then air purge the above method.

Steam cleaning method with high temperature desorption and rapid cleaning effect, can be applied to strong adsorption of pollutants after sampling cleaning. Equipment main to be composed of a vacuum bottle holder and a controlled flow steam generator, the output of the steam condensing treatment can be cold pool. Main Specifications.

Steam temperature is greater than 100 °C, steam flow greater than 80L/min, steam absolute pressure less than 100kPa, the device has a pressure valve.

The use of potassium dichromate liquid infiltration vacuum flask wall 3 to 5 times, rinsed with water to neutral, with A.1.4 method of drying spare.

A.1.4 Vacuum flask constant volume and drying pretreatment the capacity of the vacuum flask volume measurement, the amount of water can be used law, the vacuum flask to be tested after filling the water, measuring the volume of water into the bottle, the the volume is the actual volume of the vacuum flask.

Vacuum bottle dehumidification method applied to the vacuum flask volumetric water volumetric method or wet vacuum drying after treatment, the treatment method shown in Figure A.2 as shown. Connect the large-end airway of the vacuum bottle to the desiccant, connect the air inlet of the other end of the vacuum bottle to the suction pump or sampler, Empty bottle thoroughly dry. Note that in the drying process, in order to prevent laboratory air pollution on the vacuum flask, in Figure A.2 drying bottle After the connection activated carbon filter.

1-vacuum bottle; 2-drying bottle; 3- Suction pump

Figure A.2 vacuum bottle drying pretreatment schematic

A.2 air bag sampler (air bag sampling box) A.2.1 air bag sampler structure Airbag sampler structure shown in Figure A.3, by the air sampling box, sampling bag, suction pump and other components. Sampling bag inlet and seal Cover the interface connection, the sample bag is placed in the box, covered with a sealing cover, suction pump to the box exhaust, the negative pressure inside the box, the external gas into the Sampling bags, flow meters and needle valves control the suction flow rate.

1-air bag; 2-air bag sampling box; 3- air inlet; 4- exhaust port; 5- suction pump

Figure A.3 air bag sampler schematic

A.2.2 Technical requirements the air bag sampler should be sufficiently air-tight to create a negative pressure of 50 kPa. Flowmeter range of 0.4 ~ 4L/min, accuracy of not less than 2.5%.

Sampling bags can be polyester or fluoropolymer and other materials. Specifications are 5L, 10L, 30L and...