3. Primary treatment. The wastewater still contains organic solid matter-or human waste. The next stage is to seperate this from the water, and to do this, we put the wastewater into large settlement tanks, which causes the solids to sink to the bottom of the tank. We call these settled solids âsludgeâ.
Between 2004 and 2014, the share of STEM-related bachelor's degrees earned by women decreased in all seven discipline areas: engineering; computer science; earth, atmospheric and ocean sciences; physical sciences; mathematics; biological and agricultural sciences; and social sciences and psychology.
The probability of switching majors was also higher among students whose STEM grades were lower than their non-STEM grades (by 0.5 to 0.9 points), compared with those whose STEM grades were equal to or higher than their non-STEM grades (31 percent vs. 24 percent).