Assessing the potential of Khayasenegalensis in phytoremediation of heavy metals under borehole water and tannery effluent irrigation

Khayasenegalensis was planted on soil irrigated with tannery effluent and borehole water for duration of three months. Plant samples were collected after harvest and soil samples were collected before planting and after harvesting. Atomic Absorption Spectroscopy (AAS) was used to determine the concentration of heavy metals in the planting media and plant tissues. The aim was to establish the phytoremediation potential of Khayasenegalensis under these conditions. After harvesting, a noticeable decrease in the concentrations of Cd, Cr, Cu Ni, Pb and Zn in the media was observed from the initial values. The highest levels of Cd (5.53±0.56mg/kg), Cr (13.99±0.82mg/kg), Pb(10.6110.61±0.57mg/kg, Ni (8.33±2.78mg/kg)and Zn(25.72±0.00 mg/kg) accumulation were found in the roots, whereas the highest Cu (7.29±1.80mg/kg) concentrations was observed in the shoot. The roots of Khayasenegalensis were found to be suitable for the phytostabilization heavy metals in both the tannery effluent and borehole water irrigated media. In addition, Cd, Cr, Cu, Ni and Pb mainly accumulated in the Khayasenegalensisroots. The results of translocation factors (TF) and bioconcentration factors (BCF) of Khayasenegalensis for heavy metals revealed that Khayasenegalensis is an excluder plant for Cd, Cr, Pb, Ni and Zn and a potential accumulator plant for Cu serving as an ideal remediation plant for this metal. Furthermore, the increasing heavy metal contents in soil that have been irrigated with tannery effluent resulted in the accumulation of these metals inKhayasenegalensis.

Bioaccumulation And Biotransformation of BDE-47 Using Zebrafish Eleutheroembryos (Danio Rerio)

Polybrominated diphenyl ethers (PBDEs) industrially used as flame retardants are nowadays considered emerging pollutants as they are endocrine disrupting chemicals (EDCs), persistent in the environment, bioaccumulative and in addition, its hydroxylated (OH-BDEs) and methoxylated (MeO-BDEs) metabolites have similar ecotoxic properties. The aim of this work was to develop an analytical method to be applied in the study of the bioconcentration and biotransformation of BDE-47 due to its bioavailability, toxicity and high persistence and abundance in environmental samples, including humans. So, a dependable ultrasonic extraction process followed to dispersive SPE clean-up step and GC-MS-μECD detection has worked out for the determination of BDE-47 and its main biotransformation products (MeO-BDEs and OH-BDEs), considering the polarity difference. In addition, an alternative method to bioconcentration official guideline OECD 305, developed previously with zebrafish (Danio rerio) eleutheroembryos (i.e., hatched but not yet free feeding embryos) is used, reducing dramatically the animal suffering but also time and reagents. Bioconcentration factors (BCF) were calculated using first order one-compartment toxicokinetic model. The profiles found show rapid absorption in the first hours of larval development and great bioaccumulative with capacity, finding bioconcentration factors (BCF) of 6631 and 44210 at nominal concentrations of 10 and 1 μg·L-1 (< 1% LC50), respectively. Metabolization studies show increasing concentrations of the metabolites BDE-28, 2'-OH-BDE-28 and 5-MeO-BDE-47 throughout the exposure time. The results obtained show the feasibility of the method for bioaccumulation and opens the possibility of metabolic studies with zebrafish eleutheroembryos, which is a very underdeveloped field without official testing or regulation.

The Impact of 242Pu Speciation on the Bioaccumulation of Plutonium by Babylonia spirata from Jakarta Bay

The research of bioaccumulation Plutonium of Babylonia spirata from Jakarta Bay using 242Pu radiotracer has been conducted. The aquaria experiments were applied by two oxidation states of Pu speciation with three replications. The experiment was carried out by 2 steps, such as uptake and depuration. The bioavailability of 242Pu in the (III) and (IV) oxidation states from sea has been studied for Babylonia spirata. Biokinetics parameters, such as concentration factors (CFss), uptake rate constants (ku), elimination rate constants (ke), bioconcentration factors (BCF), and biological half-life (tb1/2), were investigated. The dissection is carried out to separate the parts of the gastropod's body so that the target organs for Plutonium contamination can be identified. Each part of the gastropod's body was prepared radiochemically and analyzed using an alpha spectrometer. The research shows that Pu4+ is potentially accumulated in greater value than Pu3+ by B. spirata, in which Pu is more rapidly distributed and retained longer in proboscis and gastrointestinal tract.

Hydroponic Phytoremediation of Ni, Co, and Pb by Iris Sibirica L.

Heavy metal pollution in mine wastelands is quite severe. Iris sibirica L., an emergent wetland plant, is characterized by an ability to survive under high stress of heavy metals. This study aimed to explore the phytoremediation ability of nickel (Ni), cobalt (Co), and lead (Pb) by Iris sibirica L. under hydroponic conditions. A series of tests were conducted at different metal stress conditions to evaluate the phytoextraction and tolerance of Iris sibirica L. The concentrations of Ni, Co, and Pb in plant shoots reached their highest values in 500 mg L−1 treatments, where they were 6.55%, 23.64%, and 79.24% higher than those in 300 mg L−1, respectively. The same concentrations in roots also reached their peak in 500 mg L−1 treatments, where they were 5.52%, 33.02%, and 70.15% higher than those in 300 mg L−1, respectively. Bioconcentration factors (BCF) for Ni, Co, and Pb revealed the phytoextraction ability of Iris sibirica L., and the translocation factors (TCF) showed that Ni may be most easily translocated in the plant, followed by Co and Pb. This study indicates that, compared with Ni and Co, Iris sibirica L. is more suitable for the phytoremediation of Pb-contaminated metal mine wastelands.

Toxic Elements in Soil and Rice in Ecuador

The concentration of trace toxic metals (Cr, Zn, As, Pb, Cd, Cu, and Ni) in soil and rice plants, including the stems, leaves, and grain, from the main rice-producing provinces in Ecuador, was determined. Additionally, the soils were analyzed to determine their properties, composition, total content, bioavailable fraction, and geochemical fractions of toxic elements. Approximately 30% of soil samples in the case of Cr and Cu and 10% of samples in the case of Ni exceeded the legal thresholds for Ecuador. Moreover, for Cr and Cu, approximately 4% and 13% of samples, respectively, exceeded the threshold value of 100 mg kg−1 proposed for these two elements in several international regulations. Concentrations of As, Pb, and Cd in the soils were below the threshold values established both by Ecuadorian laws and by other countries. The concentrations of metals in rice plants did not correlate linearly with the total metal concentrations in the soil, nor with their bioavailability. However, the bioconcentration factors for As, Cd, Cu, Ni, and Zn could be predicted from bioavailability by a power law with exponents ranging from −0.724 to −1.625, which is typical of accumulator plants, where trace metal homeostasis plays an important role.

Dynamics and mechanisms of bioaccumulation and elimination of Nonylphenol in Zebrafish

Nonylphenol (NP) has been widely concerned for its endocrine disrupting effects and bioconcentration in aquatic organisms. However, the knowledge on the dynamic uptake and depuration in model organisms - zebrafish (Danio rerio) were still limited. In this study, we investigated the accumulation and elimination of NP for the whole body and trunk of zebrafish by a modified pretreatment and analysis method with fewer samples. The results of acute toxicity test showed that the LC50 values of NP in zebrafish ranged from 474 µg·L− 1 for a 24-h exposure to lower than 238 µg·L− 1 for a 96-h exposure. Meanwhile, the NP concentrations in zebrafish during the depuration stage fitted the first-order kinetic model well, and the depuration rate constant (K2) was reduced with higher NP concentrations. Both the accumulation and elimination of NP in the trunk were faster than those in the whole fish, indicating the preferential transfer from viscera to muscle and rapidly diffusion in reverse. The bioconcentration factors at a steady state (BCFSS) of NP were 104–112 L·kg− 1 in the whole body and 76–104 L·kg− 1 in the trunk, respectively, suggesting that the muscle was a major position for NP storage. The BCFSS were increased within a certain concentration due to the decreasing depuration capacity inhibited by NP toxicity. To our knowledge, this study was the first to emphasize the correlation between NP exposure concentration and bioconcentration capacity.

Akumulasi Besi (Fe) pada Kerang Hijau di Perairan Tanjung Mas, Semarang

The source of iron in waters can come from human activities that carry out activities such as waste disposal in household and industrial activities. Green mussels containing iron are very dangerous for the shells themselves and for human health if consumed in excess. This study aims to analyze the concentration of iron in green mussel meat, determine the safe limit of green mussel meat for consumption by humans, and calculate the value of bioconcentration factors. This research was conducted in the sea of Tanjung Mas, Semarang. Samples taken in the form of green mussels, sediments, and water were then analyzed for iron concentrations with Atomic Absorption Spectrophotometer. The results of the study showed that the range of iron concentration values in green mussels from July to November was 39–283,97 mg/kg. The range of MTI values for adults was 1.18–4.92, while for children the range was 0.24–0.98. The value of the bioconcentration factor of green mussels and water was 3271–24839, while the value of the bioconcentration factor of green mussels and sediments was 0.010–9.647. Keywords: bioconcentration, green mussels, iron, maximum tolerable intake, Tanjung Mas