Pollution, degrees

Meanwhile, the pollution of riverine and sea waters by different hazardous chemicals such as pesticides, phenols, and, at selected places, oil products also increased. The highest pollution degree is observed in the near-mouth regions of the Don and Kuban rivers and in the areas adjacent to major ports. These ecological changes resulted in a sharp drop in the biological productivity of the sea. The trophic base for fish multifold reduced and the total fish hauls, especially those of valuable fish species, also decreased. 

Line- neutral voltage V System voltage V Impulse voltage kV Overvoltage category III IV Minimum clearances mm Pollution degree 3 4 Minimum Voltage clearance V mm ... 

In addition, the reliability of an insulating material is strongly influenced by the pollution which may occur on its surface. So, creepage distances have to be increased for a higher pollution degree. 

The third main feature of increased safety - e - is the increase of creep-age distances compared with those for pollution degree 3 and the adoption of the values for pollution degree 4 in the low voltage range. In addition, material Group IIIB is excluded. 

In the high voltage range, the creepage distances are identical to those for pollution degree 3. It should be remembered that increased safety asks for IP 54 as an adequate ingress protection degree for the enclosure (with bare live parts inside). 

Material group IIIB is not recommended for application in pollution degree 3 above 630 V and in pollution degree 4 4 For external connections, creepage distances shall have a minimum value of 3 mm... 

Organic Pollution Degree of Seaside Lakes Water... 

Romanian regimentations about water quality protection show that between the strictly surveyed parameters that can indicate organic pollution degree are chemical oxygen demand (CODMn), dissolved oxygen (DO), and biochemical oxygen demand (BOD). 

When the sulfides and COD concentration increase, the DO decrease and this fact indicates the increasing of the pollution degree. The most polluted sources of Tabacarie lake are 4, 5, 6 and 7. The mean values of the total Fe, Cr and Cu concentrations determined by the standard addition method are presented in the Table 2. 

Deposition on feather surfaces reflects also better changes of emission of some bioelements, such as, e.g. Cu in comparison to internal tissues. The accumulation of these elements in internal tissues is very often equal independently from a pollution degree. 

To control the sea surface pollution, essentially by urban sewage, a simple indicator obtained by counting the colonies of luminescent and non-luminescent bacteria developing on filters, a solid culture medium, was applied [312]. Results from a reference area and polluted sites, and their variations during the year are reported. This method allows to assess the pollution degree and the area of the polluted sites to give recommendations on cleaning. 

Verschmutzungsgrad amount of pollution, degree of contamination Verschnitt/Blend blend... 

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