sampling of solid samples(sludge, sediments), liquid samples (natural waters ... · 2020. 9. 1. ·...

Analysis, fate and risks of organic contaminants in river basins under water scarcity Valencia, 7-8 February 2011

Sampling of solid samples(sludge, sediments), liquid samples (natural waters,

wastewaters, drinking water) and biota (fish)

Alícia Navarro-Ortega,Damià Barceló

IDAEA-CSIC, Department of Environmental Chemistry, Barcelona, Spain

ICRA - Catalan Institute for Water Research, Girona, Spain

Muestreo

Preparación de lamuestraAnálisis

Tratamiento de datos

Sampling

Sample prep.

Analysis

Data treatment

How much time is necessary for each step of ananalytical procedure?

Sampling is not the longest but it is the first step of the analytical procedure so its importance has to be considered

• Sampling is a critical part in analytical methods. If not performed using adequate

techniques and according to specific objectives, the result of the analysis can

have a high bias.

• The sampling strategy should reflect the composition of the environmental

compartment. Besides, should preserve the sample in order to determine the exact

concentration.

• The design of the sampling plan is linked to the purposes of the sampling and to the

specific information one can gather.

Sampling: what we look for is what we find

STEPS

Sampling (sampling plan)

Storage and preservation

Transport

Stability

Analysis

DECISIONS

• Selection of sample locations• Frequency of sampling

• Size of the sample (mass/volume required)

• Number of sample units in each sampling site

• Selection of sampling devices, containers and their cleaning

requirements• Type of sample (discrete,

composite, multilevel or passive)

Sampling plan

CONSIDERATIONS

• Which contaminants are going to be analysed?

• Are samples required for qualitative or quantitative analysis?• Contamination from inorganics or organics can be random, uniform,

patchy, stratified or following a gradient, a preliminary testing to

establish likely distribution is recommended

• Which are the requirements of the analytical methods to be applied to

the samples

Sampling plan: organisation• Preparation of sampling site records:

• UTM coordinates• Map and description of access

• Decision of dates (meteorological conditions)• Compilation of necessary material• First time always harder than the subsequent ones

Judgmental

Systematic

Random

Types of sampling strategy

Types of environmental samples• Frequency: hours, days, weeks, months (from fast

degradation to long term monitoring)• Depending on the depth (surface, determinated

depth, depth integrated sampling, multilevel)• Discrete or composite sample

• Passive samples

DEPENDING ON THE MATRIX

• Water• Sediment

• Soil• Sludge• Biota• AirWATER PASSIVE

SAMPLER

MULTILEVEL WELL

SOIL GRABS

SOIL CORE

SEDIMENT CORE

SEDIMENT GRABS

WATER GRABGROUNDWATER FLOW

SEDIMENT LAYER

BURIED SEDIMENT LAYER

WATER COLUMN

SOIL

Types of samples• Discrete sample

• Collected at a given point within a short period of time• Represents the compartment at the exact moment of the sampling• Recommended when the source remains constant• Fails to detect episodic contamination events• Surface or determinated depth

WATER PASSIVE SAMPLER

MULTILEVEL WELL

SOIL GRABS

SOIL CORE

SEDIMENT CORE

SEDIMENT GRABS


SEDIMENT LAYER


WATER COLUMN

SOIL

• Composite sample• Collection of samples, mixed in the same container. It can also be over different sampling sites• Average characteristics of the compartment• Long term monitoring • Wastewater treatment plants monitoring


MULTILEVEL WELL

SOIL GRABS

SOIL CORE

SEDIMENT CORE

SEDIMENT GRABS


SEDIMENT LAYER


WATER COLUMN

SOIL

Types of samples

• Multilevel sample• Collection of discrete samples taken at different locations at the same time over a vertical line• Characteristics and quality of the compartment may vary within their vertical profile• Very useful to follow contamination plumes within groundwater systems


MULTILEVEL WELL

SOIL GRABS

SOIL CORE

SEDIMENT CORE

SEDIMENT GRABS


SEDIMENT LAYER


WATER COLUMN

SOIL

Types of samples

• Passive sample• Collection of a sample over time• Modern sampling strategies• Combine sampling, analyte isolation, and pre-concentration into a single step• Sampling a water body without collecting a discrete amount of samples


MULTILEVEL WELL

SOIL GRABS

SOIL CORE

SEDIMENT CORE

SEDIMENT GRABS


SEDIMENT LAYER


WATER COLUMN

SOIL

Types of samples

CONSIDERATIONS

• To retard biological action• To retard hydrolisis of chemical

compounds and complexes• To reduce volatility

• To reduce adsorption• To avoid photodegradation

ACTIONS

• pH control• Addition of chemicals• Preservation from light

(amber materials)• Refrigeration

• Freezing• In situ processing

• Mail to the main lab

(depends on the compound or chemical class to be analysed, the matrix and

the analytical technique)

Storage and preservation / TransportThe composition of the sample should be preserved during storage and

transport

Sampling devices and containers have to be chosen depending on the compound to be analysed to avoid adsorption or contamination:

• Organic compounds: avoid plastics since they contain phthalates, be careful with glass: 10% of high lipophilic compounds may be adsorbed

• Borosilicate amber glass (it can break)• Stainless steal (high acidic conditions might oxidize them)• Teflon (it is banned for perfluorinated organic compounds)• PET (it can not be reused)

• Metals: avoid glass• Plastic

• No headspace for volatile organic compounds• Cleaning protocols are important to avoid cross-contamination• Field blanks are required to check the possible contamination from the devices and containers

Considerations depending on the type of compounds to be analysed

WATER SAMPLESTYPES OF SAMPLE• Groundwater: collected from well or springs (location is not always available), over hot spots to establish contaminant plume movements

• Interstitial water: water entrapped in soil, sampled with pumps through filters or by passive samplers

CHARACTERISATION• DOC• pH

• Temperature• Conductivity

• Solved oxygen

• Should be analysed within 15 days

• Storage at 4ºC

WATER SAMPLES• Surface water (rivers, dams, lakes): bank sampling, grab samples from boats, bridges or a shore platform. Upstream or downstream agricultural, industrial areas, urban discharge, outflows of lakes, dams, WWTPs…

• Wastewater: easy to sample as they have pipes directly linked to the inflow and outflow. The most common is the composite (during 24 hours)

GRABS• Provide discrete or composite samples• Provide rapid descent in water• Prevent minimal drift from the vertical• Have a suitable closing mechanism• Should be easy to use and maintain• Have and appropiate sample capacity• Used for surface water and groundwater• Used from platform shore, boat, bridge

K-B Corer(for sampling of deep

water over 100 meters)Grab water

sampling device

WATER SAMPLES: sampling devices

PUMPS• Must be purged before obtaining the sample to avoid sampling of stagnant water• There are many different pumps• The choice will mainly depend on the distance to the sampling point• Used for groundwater, intersticial water and surface water


MULTILEVEL DEVICES• Multilevel wells that are built for the occasion and may be unique in terms of materials, depths or pumping systems• Materials for the construction must be chemically inert• Used for groundwater


PASSIVE SAMPLER• Is based on the free flow of analyte molecules from the sampled medium to a collecting medium, as a result of a difference in chemical potentials of the analyte between the two media

• It requires the deployment of a calibrated device which uses a diffusion gradient to collect pollutants over a period of days to weeks

• Applied to surface waters for integrated time screening or for sites where it is not easy to collect or pump water

• There is a variety of passive sampling methods


PASSIVE SAMPLER: devices• Diffusion-based samplers• Chemcatchers• Membrane samplers (more popular):

• semi-permeable membrane devices (SPMD) (the most effective in mimicking the biological concentration of analytes in fat tissues)• passive in situ concentration/extraction samplers (PICES)• supported-liquid membrane devices (SLM)• solvent-filled devices• sorbent-filled devices


• SPMD consists of a sealed, tubular, low-density polyethylene, flat membrane (25- to 250-µm thin), filled with a high-molecular-weight lipid –typically, high-purity synthetic triolein.

washing with KOH⇓

dialysis against nonpolar solvents⇓

clean-up(size exclusion chromatography,

SEC)(adsorption chromatography)

⇓chromatography

⇒ matrices: surface waters, ground water, agriculture run-offs, industrial effluents….. ⇒ pollutants: PAH, PCB, dioxins,

furans, organochlorine pesticides, organotin compounds, chlorophenols, polar biocides…..


SEDIMENT SAMPLES• Unconsolidate material transported by surface water or deposited under it• Sediments are not always present•They should be fine sediment (<200 μm)• Sediments have high mobility, existing monitoring sediment might not be suitable for future samplings• We have to avoid disturbance of the sediment layer

CHARACTERISATION• TOC• pH

• Composition percentage

• Long storage period• Storage at ~ -20ºC

GRABS• Provide discrete or composite samples• Provide rapid descent in water• Surface sediment sample• Used from platform shore, boat, bridge• From the shore also by hand when it is not very deep

Van Veen grab

SEDIMENT SAMPLES: sampling devices

CORES• Provide composite or layered samples• Consist on a different diameter tube made of a resistant and inert material• They can be manual (surface waters) or drop hammer (deep waters) • Used from platform shore, boat, bridge or directly inside the water

SEDIMENT SAMPLES: sampling devices

MANUAL CORES

Gravity corer in support frame

Core segments are brought into lab and labeled:archive halves, core number, core depth upper and lower end of segment

Box corer used for sediment surface sampling

SEDIMENT SAMPLES: sampling devicesASSISTED CORES

Multicorer used for both bottom-water and sediment surface sampling. It is the preferred sampling device for investigation of the water-sediment interface, flux studies and high resolution measurements in the uppermost part of the sediment

The sediment is kept in place by a titanium or stainless steel shovel, the shutters are removed and replaced by rubber stoppers

The closed tubes are carefully stored in a tube stand

SEDIMENT SAMPLES: sampling devicesASSISTED CORES

SOIL SAMPLES• Unconsolidate mantle of mineral material lying above soil rock and subjected to and influenced by environmental factors• Acts as the organic phase of the water cycle, retaining hydrophobic molecules and lixiviating the polar ones• Enormous spatial variability of chemical properties• Random sampling mixing the samples is very common

CHARACTERISATION• TOC• pH

• Composition percentage

• Cation exchange capacity


GRABS• Stainless steal augers and tubs• Minimum of 3 discrete samples mixed together• Provide discrete or composite samples• Surface soil sample (first 25 cm)

SOIL SAMPLES: sampling devices

CORES• Little cores for surface discrete sampling• Big cores for multilevel samples• Made of stainless steal or Teflon

BIOTA SAMPLES (fish)• Fish present in the water body• They are not always present or are not possible to fish• Different individuals of the same specie• Different age classes • Protected species have to be considered

CHARACTERISATION• Specie • Weight• Length

• Furcal length• Sex


ELECTRIC FISHING• An electric field is produced by a generator• The cathode is placed into the water• The anode produces electric discharges when required• The fishes swim to the anode and are paralyzed• They are fished with a net

BIOTA SAMPLES: sampling devices

Electric fishingequipment Erreka III

anode

generator

cathode

net

sampling of solid samples(sludge, sediments), liquid samples (natural waters ... · 2020. 9. 1. ·...

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