فهرست مطالب محمد رسول اسدی امیرآبادی

Heavy metals are among the most stable and non-degradable biological pollutants in the environment that can enter the water, soil, air, and therefore, the food chain. In recent years, biological methods, especially with the help of bacteria, have been used to remove heavy metals from industrial waste. The purpose of this study was to identify nickel-resistant (Ni) bacteria in the chemical refinery of Mobarakeh Steel Complex in Isfahan, Iran.

Samples of wastewater and sludge were evaluated regarding bacterial species and Ni (II)-resistance after dilution and transfer on the culture medium. Ni-resistant strain (II) and Micrococcus luteus SEHD031RS strains were selected for morphological and biochemical tests as well as Ni (II) removal, respectively.

This study showed that five strains had high Ni (II) resistance. Moreover, Micrococcus luteus SEHD031RS and Paenibacillus lautus SEHD031MRA strains showed the highest resistance to Ni (II) with growth at the concentrations of 110 and 90 mg/l, respectively. In this study, the highest nickel (II) removal rate was at pH 6 with a yield of 75.39% and the lowest nickel (II) removal rate was at pH 2 with a yield of 3.22% for Micrococcus luteus SEHD031RS strain. Ethics code: ir.skums. irac.1396-37

It can be concluded that the detected strains can be suitable choices for Ni (II) removal from industrial wastewaters according to the features mentioned in this study.

With the development of society and people's lifestyle changes/ the use of disposable containers has become inevitable. The use of these containers threatens public and personal health. At present/ Iran is among the 5 countries with the highest use of these containers in the world. This study is conducted to measure the concentrations of heavy metals including lead/ chromium and copper in disposable containers used in Shahrekord City.
For this purpose/ three disposable container samples including foam/ plant/ and plastic were provided from each company. The total number of collected samples was 72 samples were collected from three different companies.. The samples are extracted based on ISIRI standard and the concentrations of heavy metals were determined by atomic absorption spectroscopy. SPSS was used to statistically analyse the obtained data.
The mean concentrations of heavy metals in these containers for copper/ chromium and lead based on foam/ plant and plastic were (8.19/ 7.4/ 0.83- 4.5/ 6.04/ 3.33 and 3.73/ 7.09/ 0) based on the type of container glass/ food container and spoon (5.55/ 6.07/ 2.55- 5.26/ 7.48/ 2 and 4.32/ 6.75/ 0)/ and Iranian/ Ghaem and Kiyani in terms of brand (5.36/ 2.46/ 1.56- 5.68/ 10.76/ 1.68 and 4.35/ 7.1/ 1.12) per kg (mg / kg) of dry weight respectively.
The comparison of the amount of metals in disposable containers showed that the average concentration of lead compared to the maximum recommended amount of lead (2 mg.kg) is within the standard limits. And the average concentration of chromium in disposable containers is higher than the maximum recommended amount (1 mg.kg). No certain standard is determined for copper.