KOVALEN: Jurnal Riset Kimia, 11.
, 2025: 35-42 https://bestjournal.
id/index.
php/kovalen Speciation and Bioavailability of Heavy Metals Pb and Cd in Palu Bay Sediments after the Earthquake and Tsunami Husain SosidiA.
Khairuddin.
Ruslan.
Rahma Lolita Abustiana.
Aksar Ramli.
Erwin Abdul Rahim Department of Chemistry.
Faculty of Mathematics and Natural Sciences.
Tadulako University Jl.
Soekarno-Hatta Km.
Kampus Bumi Tadulako.
Tondo-Palu.
Central Sulawesi Abstract.
Major disturbances to seafloor morphology and input of terrestrial material due to the earthquaketsunami in Palu City in 2018 have the potential to alter the chemical form .
, bioavailability, and flux of lead (P.
and cadmium (C.
in Palu Bay sediments.
This study was conducted to analyze the speciation of Cd2 ions and Pb2 ions and determine the concentration of elusion ions using Diffusive Gradient in Thin Film (DGT).
this study, two methods were carried out, namely the fractionation method and the DGT method.
The results showed that the analysis of ion speciation at 3 locations using the fractionation method obtained the highest concentration of Cd2 ions of 1.
4492 mg/L at location 1 and the highest concentration of Pb 2 ions of 0.
0200 mg/L at location 3.
The results of ion analysis at 3 locations using the DGT method obtained the highest elution yield concentration of Cd2 ions of 0.
0225 mg/L at location 1 and the highest elution yield concentration of Pb 2 ions of 0155 mg/L at location 3.
This study shows that the presence of heavy metals Pb and Cd in Palu Bay sediments after the earthquake-tsunami is still detected with varying concentrations between locations.
The fractionation method is able to describe the distribution of metal speciation in sediments, while the DGT method provides information on labile fractions that are more relevant to bioavailability.
The combination of these two methods is important for understanding the potential risk of heavy metals to Palu Bay aquatic ecosystems and can be used as a basis for post-disaster environmental monitoring and management efforts.
Keywords: Fractionation, diffusive gradient in thin films (DGT), cadmium, lead Abstrak.
Gangguan besar pada morfologi dasar laut dan input material darat akibat gempa-tsunami di Kota Palu pada tahun 2018 berpotensi mengubah bentuk kimia .
ketersediaan hayati .
serta fluks Pb dan Cd di sedimen Teluk Palu.
Penelitian ini dilakukan untuk menganalisis spesiasi ion Cd 2 dan ion Pb2 serta menentukan konsentrasi ion hasil elusi menggunakan Diffusive Gradient in Thin Film (DGT).
Pada penelitian ini dilakukan dua metode yaitu metode fraksinasi dan metode DGT.
Hasil penelitian menunjukkan bahwa analisis spesiasi ion pada 3 titik lokasi menggunakan metode fraksinasi diperoleh konsentrasi tertinggi ion Cd 2 1.
mg/L pada lokasi 1 dan konsentrasi tertinggi ion Pb 2 0.
0200 mg/L pada lokasi 3.
Hasil analisis ion pada 3 titik lokasi dengan metode DGT diperoleh konsentrasi hasil elusi tertinggi ion Cd 2 0.
0225 mg/L pada lokasi 1 dan konsentrasi hasil elusi tertinggi ion Pb2 0.
0155 mg/L pada lokasi 3.
Penelitian ini menunjukkan bahwa keberadaan logam berat Pb dan Cd di sedimen Teluk Palu pasca gempa-tsunami masih terdeteksi dengan konsentrasi yang bervariasi antar lokasi.
Metode fraksinasi mampu menggambarkan distribusi spesiasi logam pada sedimen, sementara itu metode DGT memberikan informasi mengenai fraksi labil yang lebih relevan terhadap ketersediaan Kombinasi kedua metode ini penting untuk memahami potensi risiko logam berat terhadap ekosistem perairan Teluk Palu serta dapat dijadikan dasar dalam upaya pemantauan dan pengelolaan lingkungan Kata kunci: Fraksinasi, diffusive gradient in thin film (DGT), kadmium, timbal Received: March 22, 2025.
Accepted: August 21, 2025 Citation: Sosidi.
Khairuddin.
Ruslan.
Abustiana.
Ramli.
Erwin.
Speciation and Bioavailability of Heavy Metals Pb and Cd in Palu Bay Sediments after the Earthquake and Tsunami.
KOVALEN: Jurnal Riset Kimia,11.
: 35-42.
Corresponding author E-mail: husainasfah.
chem@gmail.
https://doi.
org/10.
22487/kovalen.
2477-5398/ A 2025 Sosidi et al.
This is an open-access article under the CC BY-SA license.
KOVALEN: Jurnal Riset Kimia, 11.
, 2025: 35-42 Sosidi et al.
INTRODUCTION
naturally or due to human activities and nature On 28 September 2018, the city of Palu and will have an impact both directly on the life of its surrounding areas were shaken by a 7.
organisms, and indirectly on human health.
magnitude tectonic with its epicenter on the Heavy metals, in addition to polluting waters.
mainland of Donggala.
Central Sulawesi.
The will also settle in sediments and will become earthquake triggered a 4Ae7-meter tsunami that contaminants into the bodies of living things hit the coast of Palu Bay just minutes after the through the process of bioaccumulation (Niyogi main shock.
In addition to the tsunami, et al.
, 2024.
Chen et al.
, 2.
Cadmium (C.
liquefaction and submarine landslides caused is one of the heavy metals that has soft and severe damage to infrastructure and huge loss corrosion-resistant properties so it is widely of life (Paundanan et al.
, 2025.
Alfauzi et al.
used in the chemical industry and electronic While Lead (P.
has a soft blackish This disaster not only had socio-economic brown color and is easily purified which can be impacts, but also caused significant changes to found in pure metal form as well as inorganic and organic compounds (Anggraeni et al.
ecosystems of Palu Bay.
Sediment material Liu et al.
, 2.
The presence of various types of heavy contaminants were washed into the waters.
metal ions that dissolve in seawater and that causing changes in sediment and seawater form sediments will enter the food chain system These conditions have the potential to and affect the lives of various types of increase the bioavailability of hazardous heavy organisms in it, both aquatic plants and fish.
metals such as lead (P.
and cadmium (C.
Contamination of cadmium and lead in aquatic which can harm aquatic organisms and human organisms can have a toxic impact on the survival of these organisms.
Pollution in waters To date, studies of heavy metals in Palu due to heavy metals certainly cannot be left Bay have generally been limited to measuring unchecked, special monitoring is needed and total metal concentrations, without addressing frequent measurements of heavy metal levels aspects of speciation or labile bioavailability in the aquatic environment.
that are more relevant to ecological risks.
This be used to determine the concentration of .
of Cd and Pb, and the labile metals that are in various forms of compounds fractions potentially available to biota.
Thus, the and species of both organometallic compounds and minerals that can determine the total comprehensive understanding of post-disaster concentration in a water sample (Anggraeni et impacts on heavy metal dynamics, and can , 2.
Meanwhile, bioavailability is a form provide a new scientific basis for monitoring or species of a metal that can be absorbed by and managing coastal environments after living things.
therefore, it can change physical natural disasters.
properties and can then cause toxic effects.
Speciation is an approach method that can The presence of heavy metals in marine waters also occurs due to pollution that occurs The method used in this fractionation, which is a chemical compound KOVALEN: Jurnal Riset Kimia, 11.
, 2025: 35-42 Sosidi et al.
speciation defined as the process of classifying (Merc.
Chelex-100 resin, marine sediment, and grouping various species and phases seawater, and distilled water.
contained in a medium.
Instrumentation post-disaster The tools used in this study included bioavailability of heavy metals in Palu Bay micropipettes, 60-mesh sieve.
DGT probes, sediments using modern methods such as oven, centrifuge, analytical balance, hotplate, diffusive gradient in thin films (DGT).
The DGT method in the study was chosen because it has Spectrophotometer (AAS) (Shimadz.
the unique ability to measure labile and bioavailable heavy metal fractions in situ.
Unlike conventional analytical methods such as chemical extraction or fractionation that only provide a total picture or distribution of metal speciation, the DGT method is able to simulate the process of metal diffusion from sediments to aquatic organisms.
Thus, the data obtained DGT assessing the actual ecotoxicological risk in the aquatic environment (Zhang et al.
, 2024.
Akkermans et al.
, 2023.
Luo et al.
, 2.
The DGT method works on the principle of passively binding heavy metal ions in situ.
where metals in labile form .
ree ions or weak Atomic Absorption Procedures Sampling Sediment sampling was carried out at 3 locations and 3 points each location around the Talise River.
Palu Bay.
Before the seawater was taken, its acidity was measured first and then stored in polyethylene bottles.
At each sediment samples were taken at a depth of about 15 to 30 cm from the surface.
Sediment of as much as 1000 g was then put in polyethylene plastic and stored in a cool box.
Sampling was carried out 2 times and samples that were still mixed with seawater were sedimented separated and then dried.
inorganic/organic complexe.
diffuse through the diffusive gel and bind to the binding resin.
Thus.
DGT directly measures the labile fraction
of ecologically relevant metals, not just total
MATERIALS AND METHODS
Materials The materials used in this study were (C.
lead(II) (Pb.
HCEOCC)CC) p.
(Merc.
, nitric acid (HNOCE) (Merc.
, hydrochloric acid (HC.
(Merc.
, (HCCOCC) (Merc.
, acetic acid (CHCECOOH) p.
(Merc.
, (CHCECOONHCE) Point 1 of the Pondo River estuary at 0o52Ao46.
119o52Ao15.
Point 2 to the south at 0o53Ao2.
853oS 119o 52Ao5.
Point 3 to the north at 0o51Ao51.
422oS 119o 52Ao39.
Figure 1.
Map of sampling locations in the Nelayan village of Talise sub-district KOVALEN: Jurnal Riset Kimia, 11.
, 2025: 35-42 Sosidi et al.
Easily, freely, leachable, and exchangeable (EFLE) fraction analysis DGT application on samples Weighed 500 g of finely ground sediment Weighed 5 g of sediment in a 100 mL and then put it into a 1000 mL beaker.
Then 100 Erlenmeyer flask, added 25 mL of 0.
ppm Cd2 ion solution as much as 100 mL and CH3COOH, and then shaken for 3 hours.
Then diluted with seawater to a volume of 800 mL.
centrifuged, the filtrate obtained was filtered The DGT device that has been made is then and diluted with distilled water in a 50 mL immersed in the solution in a floating position measuring flask.
The solution was then using a thread for 3 times 24 hours.
then lifted analyzed by AAS at a wavelength of 228.
8 nm and eluted using 10 mL of 1 M HNO3 for 24 for Cd2 ions and a wavelength of 217.
0 nm for The metal content in the elution solution Pb2 ions.
is then analyzed by AAS at a wavelength of Analysis of the oxidizable fraction 8 nm for Cd2 ions and a wavelength of The residue in the EFLE fraction was previously washed with 10 mL of distilled water.
and then 10 mL of 8.
8 M H2O2 solution was and heated at 85AC in a water bath for 0 nm for Pb2 ions.
RESULTS AND DISCUSSION
Fraction Analysis on Sediments several minutes.
Then 20 mL of 1 M The results of sediment analysis at 3 CH3COONH4 was added and the acidity was different locations show the distribution of adjusted to pH 2 by adding HNO3.
The mixture metals in various fractions in the sediment as was then shaken for 3 hours and centrifuged.
can be seen in Table 1.
The resulting supernatant was filtered and diluted to 50 mL with distilled water in a volumetric flask.
The filtrate was then analyzed by SSA at a wavelength of 228.
8 nm for Cd2 Table 1.
Results of EFLE fraction analysis Location Ion Concentration .
g/L) Cd2 Pb2 ions and a wavelength of 217.
0 nm for Pb2 Resistant fraction analysis The residue obtained in the previous stage Based on the data obtained in Table 1, the .
xidizable fractio.
was washed with 10 mL of determination of speciation and bioavailability distilled water and then 10 mL of aquaregia of Cd2 ions and Pb2 ions was carried out using solution was added and heated using a hotplate the fractionation method.
Metal bioavailability is at 140AC for 45 minutes.
Then centrifuged, the obtained from the metal ion species associated filtrate obtained was filtered and diluted with with each fraction phase.
In the EFLE fraction, distilled water in a 50 mL measuring flask.
The metal ions move in water until they reach solution was then analyzed by AAS at a equilibrium .
The addition of wavelength of 228.
8 nm for Cd2 ions and a wavelength of 217.
0 nm for Pb2 ions.
CH3COOH aims to form a precipitate caused by therefore, metal ions can be The highest ion concentration was obtained in Cd2 ions originating from location This is because at location 1 the source of KOVALEN: Jurnal Riset Kimia, 11.
, 2025: 35-42 Sosidi et al.
water flow passes through a residential area Based on the data in Table 3, it is known whose domestic waste is discharged into the that the results of the analysis of non- This domestic wastewater is not treated bioavailable fractions were carried out to extract before being discharged, resulting in pollution.
this species by grinding it and then destroying it In the oxidizable fraction, metal ion species with aquaregia.
Aquaregia will oxidize all metals are strongly bound to the sediment, requiring a contained in the sediment .
emaining fractio.
strong oxidant to dissolve them.
The results of The metals in this fraction are not the same as the oxidizable fractionation analysis can be seen in Table 2 below.
bioavailable nature.
According to Yap et al.
Table 2.
Results of oxidizable fraction analysis Ion Concentration .
g/L) Location Cd2 Pb2 Based on the data in Table 2, it is known that the extraction results using H2O2 which is a strong oxidizer can extract metal ions from .
, the presence of metals in this fraction is not dangerous because aquatic organisms From the three stages of the analysis results obtained were then accumulated to determine the total ions contained in the sediment.
The results of the Ctotal ion Cd2 and Pb2 tests are shown in Table Table 4.
Result of Ctotal ion Cd2 dan Pb2 sediment by releasing metal bonds in organic Potentially Location bioavailable metals if there is a change in Ion Concentration .
g/L) Cd2 Pb2 sediment conditions due to the addition of strong oxidizers to the sediment will become non-bioavailable (Gasparatos et al.
, 2.
Cd2 ions and also Pb2 ions are associated In general, the extraction stage based on with the oxidizable fraction with the lowest the distribution pattern of species in the concentration at location 1.
sediments of Palu Bay after the Earthquake and In the resistant fraction, metal species are Tsunami using the fractionation method in the not bioavailable because they are strongly analysis of Cd2 ions is F1>F2>F3.
The marine bound to the primary minerals present in the sediments of Palu Bay are not classified as polluted by Cd2 ions.
Based on the sediment The fractionation analysis can be seen in Table 3.
distribution pattern, the metal is bioavailable at Table 3.
Results location 1, potentially bioavailable at location 2.
Location and not bioavailable at location 3.
The source Ion Concentration .
g/L) of Cd2 ion contamination accumulated in the Cd2 Pb2 sediment comes from natural activities.
In the analysis of Pb2 ions, the distribution pattern of species based on the average concentration of Pb2 ions in sediments by zone is F3>F2>F1.
KOVALEN: Jurnal Riset Kimia, 11.
, 2025: 35-42 Sosidi et al.
According to Bintal Amin .
, the type of sediment can affect the concentration of heavy metal ions with the category of heavy metals in mud to sandy mud to sand.
This is thought to Table 5.
Results of analysis of Cd2 and Pb2 ion concentrations Location Ion Concentration .
g/L) Cd2 Pb2 affect the increasing depth and distance from the coast, and the course of the sediment therefore, the smaller the concentration of Pb2 ions in the sediment.
Based on the data obtained in Table 5, it is Results of Analysis of Cd ion and Pb Ion Concentrations Using the DGT Method accumulated in the binding gel with the In this DGT method, metal ion species in calculation results of each location is 0.
the sediment will diffuse through the filter mg/L at location 1, as much as 0.
0059 mg/L at 0178 mg/L at location 3.
accumulate in the binding gel layer.
Therefore.
According to Purba et al.
, .
, the levels of the metal species will not undergo chemical Cd2 ions in sediment range from 2.
145 mg/L to changes, because it will be stored in the binding gel and then eluted with an acid to determine its bioavailable and have the potential to migrate In the DGT technique, the from sediment into seawater zonally, namely average solute concentration measured over a from location 3 to location 2 and to location 1 which follows the distribution of Pb2 metal ions contamination can be reduced, and it is in sediment using the sequential extraction possible to preconcentrate without damaging According to Khairuddin et al.
, .
the sample.
The concentration of analyte the concentration of Pb2 ions in the waters of species bound by the binding gel in DGT can be Palu Bay before the Earthquake and Tsunami considered equal to the concentration of ranged from 0.
024 mg/L to 0.
048 mg/L.
The analyte species diffusing from the water to the concentration of Pb successfully absorbed by fertiliser phase.
Therefore, this method can be DGT is much greater because this tool is only used to predict the bioavailability of labile able to absorb labile metal ion species or metals such as Pb2 and Cd2 ions.
complexes with weak bonds.
However, if mg/L.
Meanwhile.
Pb2 The application of the DGT tool to sediment associated with the history of mining by is carried out using the standard addition communities along the river basin that flows namely the addition of a standard into Palu Bay.
It is strongly suspected that this solution with a known concentration to the is the result of sedimentation that has long sample to be analyzed .
pike metho.
This is occurred due to traditional gold mining by the done to increase the concentration of ions in the surrounding community.
solution so that they can enter the calibration Based on the results of the analysis of The results of the analysis of the concentration of Cd2 ions and Pb2 ions can be extraction fraction.
there is shown in Table 5.
between the easily released .
fraction a difference and the Pb2 metal ion absorbed by DGT.
This KOVALEN: Jurnal Riset Kimia, 11.
, 2025: 35-42 Sosidi et al.
is because measurements with DGT can be carried out in situ so that it can minimize changes that occur in each metal species.
Speciation techniques cannot be carried out in situ which can result in changes in the sample due to the period between the sampling time and the sample characterization time.
CONCLUSION
The results of the speciation analysis of Cd2 ions and Pb2 ions at 3 locations using the fractionation method obtained the highest concentration of Cd2 ions of 1.
4492 mg/L at location 1 and the highest concentration of Pb2 ions of 0.
0200 mg/L at location 3.
The results of ion analysis at 3 locations using the DGT concentration of Cd2 ions 0225 mg/L at location 1 and the highest elution concentration of Pb2 ions of 0.
0155 mg/L at location 3.
ACKNOWLEDGEMENTS
We would like to express our deepest gratitude to the DIPA BLU Tadulako University in the Excellent Research Scheme for the funds provided in this project with contract number:
751ag/UN28.
2/PL/2022 dated November 20.
Likewise, we would like to express our gratitude to the Rector and the LPPM of Tadulako University and all parties involved for the assistance provided in completing this REFERENCES