Estimates of Nitrogen, Phosphorus, Biochemical Oxygen Demand, and Fecal Coliforms Entering the Environment Due to Inadequate Sanitation Treatment Technologies in 108 Low and Middle Income
Countries |
Authors: |
Erica R. Fuhrmeister, Kellogg J. Schwab, and Timothy R. Julian |
Source: |
Environmental Science and Technology, 49(19):11604-11611; DOI: 10.1021/acs.est.5b02919 |
Topic(s): |
Environmental health
|
Country: |
More than one region
Multiple Regions
|
Published: |
AUG 2015 |
Abstract: |
Understanding the excretion and treatment of
human waste (feces and urine) in low and middle income
countries (LMICs) is necessary to design appropriate waste
management strategies. However, excretion and treatment are
often difficult to quantify due to decentralization of excreta
management. We address this gap by developing a
mechanistic, stochastic model to characterize phosphorus,
nitrogen, biochemical oxygen demand (BOD), and fecal
coliform pollution from human excreta for 108 LMICs. The
model estimates excretion and treatment given three scenarios:
(1) use of existing sanitation systems, (2) use of World Health
Organization-defined “improved sanitation”, and (3) use of
best available technologies. Our model estimates that more than 109 kg/yr each of phosphorus, nitrogen and BOD are produced.
Of this, 22(19-27)%, 11(7-15)%, 17(10-23)%, and 35 (23-47)% (mean and 95% range) BOD, nitrogen, phosphorus, and
fecal coliforms, respectively, are removed by existing sanitation systems. Our model estimates that upgrading to “improved
sanitation” increases mean removal slightly to between 17 and 53%. Under the best available technology scenario, only
approximately 60-80% of pollutants are treated. To reduce impact of nutrient and microbial pollution on human and
environmental health, improvements in both access to adequate sanitation and sanitation treatment efficiency are needed. |
|