en |
Urban wastes to remediate industrial sites: a case of polycyclic aromatic hydrocarbons contamination and a new process
Montoneri, E.; Tomasso, L.; Colajanni, N.; Zelano, I.; Alberi, F.; Cossa, G. & Barberis, R.
Abstract
The objective of the present paper was to
investigate the potential of urban wastes derived soluble
bioorganic substances (SBO) to perform as auxiliaries for
enhanced washing of urban soil contaminated by industrial
activities. The second objective was to show how the SBO
could be used for remediating the environmental impact
caused by industrial activities and, at the same time, be
compatible with the real-world situation demanding zero
waste processes. The SBO, isolated from four urban
biowastes, were characterized for their lipophilic/hydrophilic
(LH) and aliphatic/aromatic C ratios, and for their
surface activity properties. Soil, containing about 0.45 %
w/w polycyclic aromatic hydrocarbons (PAHs), was sampled
from a dismissed coal gasification site. The efficiency
of the SBO for washing the contaminated soil was investigated.
The most lipophilic SBO, in spite of the highest
surface activity, was the least efficient. The products having
lower LH, poorer surface activity, but higher concentration
of aromatic C were more efficient. All SBO allowed
developing a two steps process. This comprised soil
washing, and the recovery and chemical treatment of the
washing solution, to yield a PAHs–SBO precipitate and the
clean water phase to recycle to further soil washing. Data
were obtained under the same experimental conditions
using Triton X-100 commercial surfactant. The results
indicated that, although the commercial surfactant is the
most efficient in the soil washing step, it does not allow
removal of PAHs from the recovered washing solution. On
the contrary, 95–99 % PAHs removal from the recovered
SBO washing solutions is attained.
Keywords
Biosurfactants; Environment; Remediation; Biomass; Soil; Washing
|