Heavy metals in sediments and their bioaccumulation in Phragmites australis in the Anzali wetland of Iran

Accumulation of metals in both sediments and Phragmites australis organs was studied. Samples were collected from seven stations located in Anzali wetland, Iran. The samples were analyzed by inductively coupled plasma mass spectrometry(ICP-MS). The results showed that concentration of the studied metals(except As and Cd) were higher in sediments than in P.australis organs. Metal accumulation was found to be signifi cantly(P <0.05) higher in roots than in above-ground organs of P.australis. The bioaccumulation factor(BAF) and the transfer factor(TF) also verifi ed the highest rate of metal accumulation in roots and their reduced mobility from roots to the above-ground organs. Pearson correlation coeffi cient showed signifi cant relationships between metal concentrations in sediments and those in plant organs. It should be pointed out that sediment and plant samples exhibited higher metal concentrations in eastern and central parts than in western and southern parts of the wetland. The mean concentrations of all studied elements(except for Fe, V and Al) were higher in these sediment samples than in the Earth's crust and shale. High accumulation of metals in P. australis organs(roots and shoots) is indicative of their high bioavailability in sediments of the wetland. The correlation between metal concentrations in sediments and in P. australis indicates that plant organs are good bioindicators of metal pollution in sediments of Anzali wetland.

Frequencies Rotation at High Sound Pressure Levels Toward Low Frequencies

Today,analyzing of sound pressure level and frequency is considered as an important index in human society.Sound experts believe that analyzing of these parameters can help us to better understanding of work environments.Sound measurements and frequency analysis did to fix the harmful frequency in all sections in Shiraz gas power plant with sound analyzer model BSWA 308.The sound pressure levels(LP)and the one and one-third octave band were continuously measured in A and C weighting networks and slow mode for time response.Excel 2013 and Minitab 18.1 software used for statistical calculations.Results analyzed by Minitab 18.1 software.The highest harmful frequency in Shiraz Gas Power Plant(SGPP)was 50 Hz with 115 dB.The sound pressure level(SPL)ranged from 45 dB to 120 dB in one-third octave band and weighting network C.The maximum sound pressure level was in Craft electricity generator with 105.3 dB and 67 Hz.Sound pressure level in surrounded environment was 120 dB.According to the results,in this industry the sound pressure level exceeded the Occupational Exposure Level of Iran(OEL).The value of sound pressure level were higher than the Standard of occupational health.SGPP consumes 47000 cubic meters of natural gas per hour to produce 100 MW(Mega Watt)of electricity.It is very high and it is not economical and cost effective.These numbers indicate that the power plant’s efficiency is low.It could be concluded that the noise pollution is an important issue in these industries.Moreover,SGPP produce noise with loss energy.Frequencies rotation at high sound pressure levels toward low frequencies were happened.