Answer to Question #164128 in General Chemistry for kyle

Question

2. Some old electrical transformers were stored in the basement of a university maintenance building and were “forgotten.” One day a worker entered the basement and saw that some sticky, oily substance was oozing out of one of the transformers, and into a floor drain. He notified the director of grounds, who immediately realized the severity of the problem. They called in hazardous waste consulting engineers who first of all took out the transformers and eliminated the source of the polychlorinated biphenyls (PCBs) that were leaking into the storm drain. Then they traced the drain to a little stream and started taking water samples and soil samples in the stream. They discovered that the water was at 0.12 mg/L PCB, and the soil ranged from 32 mg PCB/kg (dry soil) to 0.5 mg/kg. The state environmental management required that streams contaminated with PCBs be cleaned so that the stream is “free” of PCBs. Recall that PCBs are very toxic and extremely stable in the environment and will biodegrade very slowly. If nothing was done, the contaminant in the soil would remain for perhaps hundreds of years. The cleanup resulted in the PCB concentration in the water being at 0.000073 mg/L. Was the treatment sufficient?

Explain in detail.

Answer 1

Yes, MPC in the air of the working area - 1.0 mg / m 3, vapors, 2nd hazard class (GOST 12.1.005-88; SSBT ... UEC - approximate allowable amounts of PCBs in soil (in total) - 0.06 mg / kg.