a typical limit on arsenic contamination of soil is about 10mg/kg. What is the limit in ppm? b. A typical limit on mercury pollution in soil is 100 ppb What is the limit in mg/kg?

A- An industrial wastewater stream flows at a rate of 13500 m³/d containing 100 mg/L. Suspended solids, ferric sulfate [Fe(SO4)] is used as a coagulant' at a dose of 50 mg/L. a) Assuming that there is very little in water, what is the daily lime dose? b) If the sedimentation tank removes 90% of the inlet solids, what is the daily solids production from the sedimentation tank?

Problem 4. A small community with a population of 25,200 is seeking your services as a consulting environmental engineer. They have tested their drinking water supply for coliform organisms by the fermentation tube method (five 10 ml portions per sample). They have come up with the following tabulated results for their April 2023 samples: No. of Samples 1 1 2 0 3 24 No. of + portions 5 4 3 2 1 0 No. of - portions 0 1 2 3 4 5 a. What is the calculated monthly average MPN? b. Just by looking at the calculated MPN can you comment on the safety of the drinking water of your client? -coliforms/100 ml.

A water quality analysis of a well water used for drinking water in a rural home found an arsenic concentration of 0.5 micromolar. This value seems very small to you. But you need to see if it still exceeds the drinking water standard of 10 ppbm. Is the well water violating the standard (and therefore the water would require treatment)?