Environmental Engineering FOURTH EDITION

44 ENVZROWNTALENGINEERING Table 3-1. Adult Deaths in the United States/lOO,OOO Population (National Center for Health Statistics ...

Risk Analysis 45 For all causes of death, the annual SMR is 106 95.8 SMR(t0tal) = - = 1.1. Without performing a test of statisti ...

46 ENVIRONMENTAL ENGINEERING The factor 2000/8760 in Eq. (3.4~) is the fraction of hours per year spent in the workplace. For ai ...

Riskhalysis 47 ECOSYSTEM RISK ASSESSMENT Regulation of toxic or hazardous substances often requires an assessment of hazard or r ...

48 ENVIRONMENTAL ENGINEmG background is 25 mrem per source per year. Average background is about 360 mrem per year. How many fat ...

RiskAnalysis 49 effects resulting from these incidents. Assume that toxic material leaked into the soil, air, and drinking water ...

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Chapter 4 Water Pol I ut ion Although people intuitively relate filth to disease, the transmission of disease by pathogenic orga ...

52 ENVIRONMENTALENGINEERING as discussed in Chap. 11. Point source pollution comes mainly from industrial facilities and municip ...

Water Pollution 53 has a population equivalent of 1,000/0.2, or 5,000. The current estimate of the popu- lation equivalent of mu ...

54 ENVIRONMENTAL, ENGINEERING By far the most notorious recent incident has been the Exxon Valdez spill in Prince William Sound ...

Water Pollution 55 Three categories of organisms make up an ecosystem. The producers use energy from the sun and nutrients like ...

56 ENVIRONMENTAL ENGINEERTNG Figure 4-1. A typical terrestrial ecosystem. The numbers refer to trophic level above the autotroph ...

Water Pollution 57 perturbations. In addition to the direct effect of toxic materials like metals, pesti- cides, and synthetic o ...

58 ENVIRONMENTAL ENGINEERING c a, L E =l F w ~ Digestion-very rate of decomposition high microbial degradation Residual energy ...

Water Pollution 59 DEAD Organic nitrogen Organic ORGANICS carbon \ Organic sulfur WASTES Organic phosphorus INITIAL PRODUCTS Amm ...

60 ENVIRONMENTAL, ENGINEEmG DEAD Organic nitrogen Organic carbon Organic sulfur WASTES Organic phosphorus INITIAL PRODUCTS Organ ...

Water Polhtion 61 humans, but have little impact on stream communities. For example, coliform bac- teria are an indicator of ani ...

62 ENVIRONMENTAL ENGINEERING 0 5 10 15 20 25 30 Time Figure 4-6. Amount of oxygen required at any time t(z(t)) for various deoxy ...

Water Pollution 63 Time Figure 4-7. Dissolved oxygen used (BOD) at any time t plus the dissolved oxygen still needed at time t(z ...