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18) Which pH is closest to normal body pH? 

400 cubic yards of gasoline-contaminated soil will be treated using bioremediation.  The soil has low organic content.  It is desired to bring the water moisture level to 60% to maintain high reaction rates.  Calculate how much water (cubic feet) should be added. Soil porosity, n = 30% Initial saturation, S = 20% Conversion: 1 yd = 3 ft

Hydraulic conductivity of soil is measured as 2×10-2  cm/sec.  After an accident, a truck carrying dissolved salt solution releases its contents to surface.  The distance between the spill and a groundwater well is 1600 meter.  The groundwater elevation at the spill location is 5.5 meter and well location is 5.3 meters. Porosity of soil is 0.4.  Travel time of contaminant to the well is most nearly (years):

100 mL of a solution with a TOC (total organic carbon) concentration of 0.5% is placed in each of the five containers with activated carbon and shaken for 48 hours. The samples are filtered and the concentration of TOC measured, yielding the following analyses: Test beaker no.:          1          2          3          4          5 Carbon (grams):          10        8          6          4          2 TOC (mg/L):               42        53        85        129      267   The Freundlich isotherm is to be used:  X/M = k Cf 1/n The value of X (TOC removed) in the 1st beaker is (mg):

100 mL of a solution with a TOC (total organic carbon) concentration of 0.5% is placed in each of the five containers with activated carbon and shaken for 48 hours. The samples are filtered and the concentration of TOC measured, yielding the following analyses: Test beaker no.:          1          2          3          4          5 Carbon (grams):          10        8          6          4          2 TOC (mg/L):               42        53        85        129      267   The Freundlich isotherm is to be used:  X/M = k Cf 1/n The value of X (TOC removed) in the 1st beaker is (mg):

The following data have been collected during the trial burn studies for incineration of a waste mixture.  The principle hazardous constituent (POHC) for the waste has been determined as dioxin.   Compound                  inlet flow rate (lb/hr)              outlet flow rate (lb/hr) Benzene                      1200                                                    4 Toluene                       800                                                      3 Dioxin                         30                                                        1 Destruction removal efficiency for the POHC is:

The following data have been collected during the trial burn studies for incineration of a waste mixture.  The principle hazardous constituent (POHC) for the waste has been determined as dioxin.   Compound                  inlet flow rate (lb/hr)              outlet flow rate (lb/hr) Benzene                      1200                                                    4 Toluene                       800                                                      3 Dioxin                         30                                                        1 Destruction removal efficiency for the POHC is:

Solid waste with the density of 110 kg/m3 is spread in a 0.5 m layer at a landfill. If a steel wheeled compactor can achieve a density of 400 kg/m3, what is the compaction ratio (CR)? Note:   CR= Vinitial/Vfinal

Solid waste with the density of 110 kg/m3 is spread in a 0.5 m layer at a landfill. If a steel wheeled compactor can achieve a density of 400 kg/m3, what is the compaction ratio (CR)? Note:   CR= Vinitial/Vfinal

For subsurface investigation, soil borings are considered as: