xiv Abbreviations and symbols
psi pound per square inch
psi pound per square inch (referring to pressure)
PVC polyvinyl chloride
RCRA Resource Conservation and Recovery Act of the U.S.A.
RI rapid infiltration process (referring to land treatment)
RMP red mud plastic
rpm revolution per minute
s or sec second
S sulfur
SAR sodium adsorption ratio
SD stocking density (of fish or aquatic weeds)
SF subsurface flow (constructed wetlands)
SI international system
SOx sulfur oxides in various oxidation states
SR slow rate (irrigation) process (referring to land treatment)
SS suspended solids
TKN total Kjeldahl nitrogen = organic N + NH 4 +-N + NH 3 -N
TLW total live weight of animal
TN total nitrogen
TOC total organic carbon
ton metric tonne = 1000 kg
TP total phosphorus
TS total solids
TSS total suspended solids
TVS total volatile solids
TWW total wet weight
U.N. United Nations
U.S. DA United States Department of Agriculture
U.S. EPA United States Environmental Protection Agency
UASB upflow anaerobic sludge blanket digester
UMER unit mass emission rate (referring to tapioca starch
wastewater)
UNEP United Nations Environment Program
UNESCO United Nations Eduction, Science and Culture Organization
UV ultraviolet
VIP ventilated improved pit
VSS volatile suspended solids
W Watt
WHO World Health Organization
WHP water hyacinth ponds
wk week