The Heavy Metal Characteristics (Pb and Cu) in Wideng Crab Tissue from the Gonjol River, Demak

Objective and Background: The Gonjol river serves as a lifeline for the communities surrounding Demak's brackish water ponds. Currently, factory waste is poisoning rivers. The purpose of this research was to investigate the levels of heavy metals Pb and Cu in Wideng crab tissue, water, and sediment in the Gonjol river's upper course and estuary. Methods: This study was place from January to March 2020. Heavy metal concentration was determined using atomic absorption spectroscopy. The linear regression method was used to analyze the data. Results: Except for Cu in upstream and estuary sediments, the concentration of Pb and Cu in the waters, sediments, and Wideng crab tissue remained below the acceptable limits. Heavy metals Pb and Cu in both sediment and tissue did not reveal a significant association in the upstream and estuary, although there was a correlation between water and tissue. There is no association between silt and water in the upstream and estuary. The river's quality is based on the Decree of the Minister of the Environment of the Republic of Indonesia No.115 of 2003, which places it in category C, which means it has moderate levels of Pb and Cu pollution. While tissue and sediment levels are below the tolerance limit. Conclusion: The state of the Gonjol River is a source of concern, particularly the circumstances of Cu and Pb, which allow bioaccumulation in the future, posing a threat to the ecosystem and the communities surrounding it.

Ultrastructural Changes of the Digestive Tract of Pomacea canaliculata Exposed to Copper at Lethal Concentration

The present study was undertaken to elucidate the basis of cellular reactions and to verify the suitability of Pomacea canaliculata digestive tract ultrastructure as a biomarker for assessing the Cu pollution in freshwater environments. Two-month-old P. canaliculata were exposed to 96-h lethal concentration of Cu (0.15 mg L-1) for 96 h. Electron microscope investigations showed different alterations of organelles in the epithelial cells lining the esophagus and intestine. The most striking changes were damages to the mitochondria, RER, and nucleus typified by loss of cristae and degeneration of mitochondria; degranulation and fragmentation of RER. In nucleus, karyolysis and rupture of nuclear envelope were observed. These changes were attributed to membrane destabilization and increased membrane permeability to ions under the influence of toxicants or heavy metals. These findings indicate the possibility of using the P. canaliculata as biomonitor for Cu contamination in the freshwater environment.

Evaluation Heavy Metals Pollution in Topsoil around Dalate Power Plant in Erdos

The concentrations of heavy metals(Cd, Cr, Zn, Cu and Pb) in topsoil and dust-fall around Dalate Power Plant were analyzed for assessing heavy metals pollution risk in Erdos, China. Topsoil and plants were collected in open area. The results show topsoil windward of Dalate Plant is clean. Topsoil leeward is polluted by heavy metals, heavy metals concentrations increase till 2500m, then decrease to background level. Dust-fall is an important heavy-metals source leeward.CF and PN indicate there are slight Cr and Cd pollution in 2500m topsoil. The rest topsoil is suspected contaminated by heavy metals. Ex indicate Cr and Cd pollution can be monitored and restored by Didymodon vinealis and Bryum argenteum Hedw., Zn and Cu pollution can be monitored and restores by Populus sinonii and Artemisia ordosica in the area.

Assessment of Soil Heavy Metal Cu, Zn and Cd Pollution in Beijing, China

The soil heavy metal pollution have be paid more attention because the sources of soil heavy metals become multiple and complicated with the accelerated urbanization. According to this research, the order of spatial distribution of soil heavy metal Cu, Zn and Cd pollution in Beijing shows that: the center district > suburb > outer suburb. The soil pollution by Zn is more serious in Beijing and the grade of the soil Zn pollution has reached highest in the central district. By comparison, the soil pollution by Cu and Cd is slight, the soil in central district, Chaoyang, Changping and Miyun has caught light Cu pollution, and only in center district, Chaoyang and Fengtai has caught light Cd pollution.

Effect of FA/O Chelating Agent on Copper Ion Removing on Silicon Surface

Along with the feature size reducing and the increase of integration level rapidly in ULSI，the request for metal impurities contamination on silicon substrate surface appears specially rigorous. In this paper the chelating agent was added in cleaning solution in order to removing copper ion. FA/O, a new kind of chelating agent was studied in RCA cleaning solutions, which has 13 chelating rings and is free of sodium, stable and easily soluble. The XPS and GFAAS measured results indicate that FA/O is more efficient than NH4OH as a ligand. Cu contaminations on silicon wafer can be removed remarkably when adding a little FA/O to the cleaning solution or polishing slurry. When the chelating agent concentration of cleaning solution is 0.1% the removal rate of Cu atom reaches 83 percent. The FA/O chelating agent substituting NH4OH in SC-1 may simplify cleaning steps, and one cleaning step can remove Cu pollution on silicon wafer surface and meet the requirements of microelectronics technology.