Environmental Engineering Reference
In-Depth Information
Fig. 3.11
Schematic diagram of coal fly ash pond assembly (I-III) showing ash slurry supply pipe
from from CPP discharge points and recycling of treated water back to CPP for reuse
5
Landfil Leachate and Hazardous Wastewater
Utilization for Establishment of High Rate Algal
Ponds for Biodiesel Production
Algae grown in wastewater (= high rate algal ponds, HRAPs) assimilate nutrients
and thus subsequent harvest of the algal biomass recovers the nutrients from the
wastewater. Leachate from hazardous waste dump sites are being put to use to es-
tablish HRAPs for production of biodiesel (Fig.
3.14
; Park et al.
2011
). The har-
vested phytomass of aquatic plants used in treatment wetlands serves as a valuable
feedstock for biogas production (Abbassi et al.
1991
).
6 Conclusions
The engineered phyto-cover functions as a sponge and pump system, with the root
zone acting as the sponge, and trees acting as the solar-driven pumps. In contrast
to restrictive permeability barrier design, the engineered phyto-cover design in-
volves the storage of free water in soil pores and the extraction of stored water
by the tree roots. Use of constructed wetlands is spreading rapidly in developed
