Mesopotamian Journal of Marine Science

In this present study, the bioaccumulation of heavy metal, cadmium (Cd) and major element magnesium (Mg), in the liver tissues of Oreochromis niloticus, was investigated after exposing the fish over 96 h period to Cd LC50 (0.8 mg/l) and Mg LC50 (3.03 mg/l). These tissues were investigated by light and scanning electron microscopy. Scanning electron microscopic X-ray microanalysis of fish liver exposed to Cd or Mg confirmed that these metals were accumulated in liver tissues.

Diversity, abundance and community structure of fish species in the lower part of the Euphrates River was investigated during May 2016 to April 2017. Three stations were selected to conduct the work. Monthly variance of water temperature ranged from 11ºC in January and February to 31ºC in August, turbidity differs from 2.31 in June to 24.10 NTU in November. The overall values of hydrogen-ion differ from 7.52 in April to 8.27 in November and December. The overall values of salinity in the work area were 0.91 ‰ in October to 1.52 ‰ in May. Several fishing methods were used to collect the samples of fishes. A total of 4380 specimens' of fish were collected included 23 fish species belonging to 23 genera and 11 families, ten of them represented native fish species, eight alien fish species and five marine species. Oreochroims aureus was the most abundance species formed 34.27 % of the total number then Liza abu (24.66 %) of the total number of species and Carassius gibelo (14.36 %). Values of three dominate species (D3) was 73.29 %. The mean values of diversity index (H) in the study area ranged from 1.11 to 1.92, evenness index (J) from 0.53 to 0.90 and richness index (D) from 1.15 to 2.33. The study showed the dominance of small species of exotic and native fish in the study area and the scarcity of large economic species due to the overfishing.

Bioaccumulation of Ulothrix zonate was compared for cadmium, copper, nickel, and zinc removal at various concentrations and contact time. The results of the present investigation showed that the lowest amount of Cd, Cu, Ni and Zn was adsorbed when the initial heavy metal concentration was 10 ppm whereas Cd showed highest concentration at 20 ppm and Cu exhibited greatest removal at 30 ppm. The metals Ni and Zn exhibited highest removal at 40 ppm. The value of Freundlich model constant (1/n) for different metals ranged from 0.334 to 0.721 and the values of Langmuir separation factor values (RL) varied between 0.111 and 0.722 which indicated favorable bio-sorption by the biomass of the algae. The order of metals uptake was found to be Ni>Zn>Cu>Cd. The finding of the study showed that U. zonate has much potential as a biosorbent for the sorption of Cd, Cu, Ni and Zn and indicated that the metal uptake was concentration-independent for Cd and Zn whereas for Cu and Ni an increase in initial metal concentration resulted in higher metal uptake. This present study leads the way for the future studies on the use of algae as a cheap bio-adsorbent for heavy metals removal in Iraq which is suffering from huge inland waste water.

Industrial wastewater and other polluted water need to be treated to make it possible to discharge into rivers and reuse them. Adsorption takes the importance of ways to remove organic and inorganic pollutants in water. The search for materials that are locally available and cheap to use as adsorbent surfaces. The Iraqi porcellanite powder can be used to remove the dye of Rhodamine B in batch method. The effect of various experimental parameters such as contact time, temperature, solution pH, weight of adsorbent initial dye concentration, ionic strength were investigated. The adsorption studies included both equilibrium adsorption isotherms and kinetics. The applicability of Langmuir and Freundlich equations was investigated at different temperature, and the Freundlich isotherm exhibited the best fit with experimental data. The thermodynamic parameters indicated that the adsorption was a spontaneous process (ΔG was negative), the negative value of ΔH indicate endothermic and ΔS was positive value (random), the kinetic data well described by Pseudo-second order kinetic model with intra particle diffusion as one of the rate limitring steps.

Sawa Lake is an abnormal lake in Iraq. It was characterized by the high degree of salinity among the Iraqi marshes. It is a euhyline water body of no inflow and outflow. The lake is an elongated closed basin with no channel of surface water available to it. The results of the present study are showed three types of fauna, the biggest numbers of fauna belong to Ostracods. The other fauna are represented in type of algae (Charophyta) and one genus of Gastropods. The SEM analysis indicated that the organisms are affected with water lake chemistry, the element S exists in the wall of Charophyta and Ostracoda, while the gastropods does not contain this element. They concluded that these organisms were affected with the salinity except gastropods genus which transport by bird feet from Caspian Sea. There are many fauna that occurred in Sawa Lake, these are reflect of fresh water sources enter to the lake.