Employing sodium hydroxide in desulfurization of the actual heavy crude oil: Theoretical optimization and experimental evaluation

Trace elements contamination and accumulation in bottom sediment represents a risk to environment and aquatic biota. Their anthropogenic or natural discharge, extension and cumulation can cause large scale of ecological destructions. Bioaccumulation and biomagnification is capable of leading to toxic level of these chemical substances in fish and other fresh water organisms (benthos, zooplankton), even when the exposure is low. The fish contamination through trophic structure can cause serious consequences to human health. The aim of the manuscript was to assemble and summarize the latest literature on the environmental and the aquatic biota effects of trace element contamination of bottom sediments. The article is also a review of new methods for trace elements elimination and their assessment to impact on aquatic organisms. Based on collected scientific publications in last 20 years the most common and important trace elements in aquatic ecosystem are Chromium, Arsenic, Mercury, Cadmium and Copper. These compounds are dangerous for living organisms and can disrupt their homeostasis as well as a cardiovascular, nervous and digestive system. Nowadays exist many instrumental methods, which are available to determine the trace element concentration such as PMF, INNA, BCR, XRF and bioassay. In searched studies the most preferred and used analyse of trace element concentration in aquatic bottom sediments is bioassay. This biological method is good complement to physical and chemical analyses in procedures of sediment quality assessment. Bioassay method can indicate sensitive response of planktonic organisms to various trace elements and provide information about the real risk to aquatic life.

Trace elements in aquatic environment. Origin, distribution, assessment and toxicity effect for the aquatic biota

Cross-linked chitosan into graphene oxide-iron(III) oxide hydroxide as nano-biosorbent for Pd(II) and Cd(II) removal.

Iron-Doped Mesoporous Powders of Hydroxyapatite as Molybdenum-Impregnated Catalysts for Deep Oxidative Desulfurization of Model Fuel: Synthesis and Experimental and Theoretical Studies

This paper revealed that the level of certain potentially toxic elements (PTEs) can be reflected in stream and terrace sediments from Harsit Stream in Northeast Turkey. The potential toxicity of these elements was established by determining and interpreting the enrichment factor (EF), contamination index (Pi), ecological risk index (
 $$ {E}_{\mathrm{r}}^i $$
 ), modified hazard quotient (mHQ), hazard quotient (HQ), and hazard index (HI). The distribution of PTEs in the sediment samples was non-uniform along the different sites of the stream. The change in concentration was attributed to the release of these elements from different sources (agricultural activities, industrial activities, and gasoline discharges). Results indicated that the stream sediments were locally contaminated by the following PTEs: Pb, As, and Cd based on EF values; Cu, Pb, Zn, As, Cd, and Hg based on Pi; Pb, Cd, and Hg based on $$ {E}_{\mathrm{r}}^i $$
 ; and Pb, As, Cd, and Hg based on mHQ. According to the HQ and HI values of Pb, risks were posed to human health especially to children. Meanwhile, terrace sediments were locally contaminated as follows: Zn and As based on EF; Cu, Pb, Zn, As, and Cd based on Pi; and Zn and Cd based on $$ {E}_{\mathrm{r}}^i $$
 . The HQ and HI values of As were found to be > 1, suggesting a high chance of health risk to children. The PTE levels and the local distribution pattern revealed that agricultural activities, industrial functions, and gas stations along the stream were probable sources of toxic element contamination in sediments from the Harsit Stream. These findings can help evaluate the potential toxicity risks affecting living organisms.

Distinct contamination indices for evaluating potentially toxic element levels in stream sediments: a case study of the Harşit Stream (NE Turkey)

The article dealt with Pollution of our environment with different metal. These metal called heavy metal attributed to its toxicity properties. Cr, Mn, Fe, Co, Ni, Cu, Cd, Zn, Hg, Ar, Pb, Ag, are example of heavy metals pollutant. The ways and methods of polluted the environment are different and all be as a waste of humans activities. Pollution of soil and water with this waste drive to polluted or raise the ratio or concentration of metal in plants. Humans and animals are feeding to plant products which mean raise of concentration of metal at human and animal more than its normal ratio. At last the property of cumulating for heavy metal will hike the concentration of them at living organism, animals and humans bodies. Then it leads to toxicity with it. This Article highlighted to toxicity of heavy metal as pollutant and it`s risk to environment and living life.

Environmental Pollution with the Heavy Metal Compound

/pdf/oxidative-desulfurization-of-hydrotreated-gas-oil-using-4ph8zimsdr.pdf

Wessal Metaab Khamis Al-Jubori

Papers

Environmental Pollution with the Heavy Metal Compound

Oxidative Desulfurization of Hydrotreated Gas Oil using Fe2O3 and Pd Loaded over Activated Carbon as Catalysts