Volatile Organic Compounds in Soil Gas and Groundwater

Using blow and sweep capture-Gas chromatography can be used to detect soil gas and groundwaterV O C sMonitoring can determine different forms of existenceV O C s. Includes sampling and capture-Analyze the entire process, which consists of a blowing and capturing pre-treatment system, a volatile organic compound monitoring subsystem, and a data acquisition and processing subsystem. Monitor and summarize all component concentration information and work status information, while generating reports, storing data, recording historical data, and communicating with environmental protection departments through networking. Provides relatively fast and low-cost information on site pollution, which can guide the next sampling plan and research on how to select more affordable and accurate investigation and suitable remediation techniques. Widely applicable for monitoring volatile organic compounds in various soil gases and groundwater,V O C sQualitative and quantitative analysis.

Monitoring and analysis module

System parameters:

1.Quantitative lower limit: ≤ groundwater standard limit1/4

2.System qualitative repeatability: ≤0.5%The system is determined

Quantity repeatability:≤5%System indication error: ±10%

3.System standard sample addition test:90%-110%

4.Short term stability of the system: ≤5%（24h）

5.Long term stability of the system: ≤5%（7d）

6.System linearity:R≥0.99

7.Analysis liquid volume: ＜50mL

8.Program heating repeatability: ≤0.2%

9.systemzuiMinor maintenance cycle:≥168h

10.Carrier gas type: nitrogen

11.Range:25%-400%Groundwater limit

Functional technical parameters:

Gas chromatograph column temperature box parameters:

1.Operating temperature range: above room temperature+8℃～400℃；

2.Programmable temperature rise: ≥29step30Platform;

3.ConfigurablezuiHigh heating rate:≥250℃/min（

with0.01℃/minIncrease);

4.Cooling and cooling of column temperature box（20-25℃ room temperature)

from350℃ drops to50℃≤400s；

5. Uniformity of furnace temperature:≤3%；

Technical parameters of injection port:

1.zuiHigh operating temperature≥450°C；

2.High precision electronic pressure/Flow control, column head pressure setting range:0～100psi;optional0～150psi）；

Column head pressure control setting accuracy:0.001psi

3.zuiLarge diversion ratio≥1:10000；

Technical parameters of detector:

1.Hydrogen flame ionization detector（FID）High precision electronic flow rate/Pressure control,zuiHigh operating temperature430℃；

2.zuiSmall detection limit≤1.5 pg C/s(Hexadecane), baseline drift（30min）≤3×10^-13A；

baseline noise≤8×10^-14 ADynamic linear range ≥10^7；

3.Data collection frequency:zuitall1000Hz；

4.Microcell electron capture detector（uECD）：zuiHigh operating temperature:400℃, the radioactive source is10mCiof63NiBeta rays,

zuiLow detection limit≤6×10^-15g/mLBaseline drift of (C-666)（30 min）≤5HzBaseline noise ≤1Hz；

linear range ≥1×10^4.

Purge Trap

Technical parameters for blowing:

1.Volume:5mlThe25mlOptional;

2.Heating method: direct resistance heating;

3.zuiHigh operating temperature:≥350℃，zuiHigh heating rate:>2400℃/Minutes, cooling rate: ≥240℃/min

(In)50Within seconds,200℃ drops to30℃）；

4.The sample heater is an infrared sample heater, which can control the temperature and heat the sample water sample to ensure that the temperature at the center and edge of the sample is consistent,

Heating is uniform, and the blowing condition of the sample can be observed while heating;

5.The parameter setting and control function of electronic pressure control for all flow paths in the system, with the communication function to trigger the operation of the gas chromatograph.

Technical parameters of data acquisition and control system:

1.Has abnormal information feedback function (gas shortage alarm, component failure alarm, and over limit alarm, etc.);

2.After an unexpected power outage, it should have the function of automatically discharging the test substance and reagent being measured before the power outage, and automatically cleaning each channel

Reset to restart the measurement state. If it is in a heating state before power failure, it can automatically cool down after being powered on again and reset to restart

The state of initial measurement;

3.The system has functions such as data and operation log collection, storage, processing, display, and output, and can store at least12Original data for months

And running logs, and possessingsanjiOperation management permissions, general operators can only query corresponding logs and instrument settings parameters;

4.The system has automatic sample verification and calibration functions, and records the results in the operation log;

5.Capable of adding maintenance, fault, automatic calibration, and standard verification labels to different test data;

6.Automatic dilution function: During the injection process, the sample or standard solution is automatically diluted to meet the measurement requirements for high concentration samples.

Measurement items:sanChloromethane, dichloromethane1,2-Dichloroethane1,1-Dichloroethylene, cis-1,2-Dichloroethylene

trans-1,2-Dichloroethylene, trichloroethylene, tetrachloroethylene, tribromomethane, styrene, benzene, toluene, ethylbenzene, meta-Paraxylene, o-xylene, isopropylbenzene, chlorobenzene1,2-Dichlorobenzene1,4-Dichlorobenzene.

Soil gas module:

1.The entire sampling pipeline is made of inert materials such as Teflon or stainless steel.

2.Two sampling pipelines, located respectively100~500ml/minand500~2000ml/minAccurate adjustment within the range.

3.Real time display of exhaust flow rate, flow display instrument range:0~3000ml/min；

4.Negative pressure gauge range0~2.5KPa;Resolution ≤5Pb；

5.real-time displayVOCTheCO2TheO2TheCH4TheH2STesting data;

6.VOCRange:0-20PPM，zuiSmall exploration measurement1.5ppb;

7.Carbon dioxide: Range:0-1000 ppmAccuracy: ±3%FSResolution:1 ppm；

8.Oxygen: Range0-35%VOL, Resolution0.1%Accuracy ±0.5%；

9.Methane: Range:0-5VOL %Accuracy: ±5%FSResolution:0.01 VOL %；

10.hydrogen sulfide:0 - 10 ppm,Accuracy: ＜2%, Resolution< 0.01 ppm；

11.Real time display of sampling flow rate and pressure; The sampling flow rate can be automatically adapted, and the pumping flow rate can be automatically adjusted according to the well conditions to control the start and stop of the pump;

The air inlet is equipped with a drying device for easy replacement, and the replacement frequency should not be less than12Hourly working conditions required;

Sampling pump flushing and sampling:

Pump body material:316stainless steel;Pump body diameter:50mm;洗井流量：0.1L~12L/minadjustable;zuiHigh lift:70m;

Hydrodynamics: Detecting groundwater flow velocity, direction, water temperature, and discharge water level parameters; zuiSmall detection particle size≤10um；

Flow velocity measurement range:0-30mm/s;Flow velocity measurement accuracy: ≤1um/s;Measurement direction accuracy ≤±2°；

Direction resolution:0.1°; Probe applicable depth: not less than300rice;

Probe environmental adaptability: meets the requirements4℃~70Temperature range of ℃; Power supply method:AC220VorDC12V;

Working temperature and humidity range:-10℃~50℃，≤90%RH;

Downview camera and360Full surround view camerafangObserving the state of water bodies;

Monitoring visual acuity: ≥2.7mm*2mm;Discharge range:0~20mCable length: ≥100m；

Measurement accuracy:±2mmMeasurement resolution:1mmProbe diameter: ≤22mm；

Output: Digital quantity, can also be linked with airbag pump or sampling pump.

Groundwater module

Sampling preprocessing:

water temperature:

Testing method: electrode method Measuring range:-5℃～50Accuracy at ℃: ≤±0.1℃ resolution: ≤0.01℃

pH:

Test method: Glass electrode method Measuring range:0～14pHAccuracy: ≤±0.1pHResolution: ≤0.01pH

Conductivity:

Testing method: electrode method Measuring range:0～100mS/cmAccuracy: ±1%Resolution:0.1Ms/cm

Redox potential:

Testing method: electrode method Measuring range:-999~999mVAccuracy: ±20 mVResolution:1mV

Turbidity:

Testing method: Optical method Measuring range:0.1～1000NTUAccuracy: ±0.3NTUResolution: Resolution0.01NTU

Airbag pump well cleaning sampling:

Diameter of airbag pump body: not greater than43mm.

Length of airbag pump body: less than50cm.

Airbag pump head: standard configuration70rice,Can be achieved as needed300mEven higher lift.

Airbag pump supply pipe: used in conjunction with airbag pump,PVCmaterial Airbag pump outlet pipe: Used in conjunction with the airbag pump, made of PTFE material.

Work environment:

1.Power Supply:220VMunicipal power supply;2.Environmental temperature: outdoor temperature-25˚C~45˚C；3.Environmental humidity: not exceeding90%；

4.Insulation impedance:2MAbove Ω;

Data storage:

Capable of storing data locally for more than one year, including but not limited to: instrument operation status, monitoring data, alarm information, etc.

Data transmission and remote control:

1.Equipped with wireless transmission function, able to transmit through wireless network（4Gor5GTransmitting data to the purchaser through communicationdingThe data terminal.

2.Supporting remote control function:

① Support automatic generation of sampling reports, including site number, sampling point location, sampling start time, sampling end time

Monitoring indicator values;

② Support program timed sampling function, which can automatically complete well flushing work and achieve timed and fixed-point continuous sampling through software control,

Can achieve intermittent sampling at different time periods;

③ Support graphical interface, capable of displaying historical monitoring data in a graphical manner. Data can be automatically generated and exportedExcelFormat for analysis purposes;

④ Support remote control to start real-time sampling function, support through mobile phone orPCReal time sampling and returning detection values.

3.Equipped with video surveillance function, with video archiving and backtracking time not less than48Hour.

4.Data can be viewed and displayed on-site, including real-time data, historical data, and quality control data;

Automatic well washing function: flow range0-16 L/min，zuiLarge lift300Mi, with frequency conversion function. Sampling pump integrated with underground water level

The water temperature sensor can be placed in a standard monitoring well. The downhole probe has temperature compensation function.

Manual sampling interface:Can be connected to flat mouth bottles or glass bottles for sampling;

Conventional factor probe access port:MeasurablepHTheORPAnd conductivity, etc. The range of monitoring indicators complies with the Technical Specification for Groundwater Environmental Monitoring

（HJ 164-2020）The relevant requirements for monitoring conventional indicators in China.

Sampling pipeline:Using inert materials or undergoing inert treatment. Set up well washing wastewater that meets the environmental protection requirements of the surrounding area according to the site conditions

Sampling tailwater discharge method and collection device.