Volume 14 [2012]

Arsenic is an ubiquitous and highly toxic metalloid widely distributed in the environment through
both natural and anthropogenic pathways (Liu et al., 2004) and its presence in food composites is a
matter of concerns to the well being of both humans and animals. In fact, As has been recently
found in drinking water (network and groundwater) in some Italian regions, including Lazio (Central
Italy), at concentration ranging between 25 and 80 μg L-1, higher than the limits set by law (10 μg L-
1) where Arsenic-contaminated groundwaters are often used in agriculture to irrigate crops for food
and animal consumption; this determines that arsenic can enter human food chain. Inorganic or
organic species of the metalloid arsenic occur in the environment. Either inorganic or organic As
occurs in the environment and inorganic forms (iAs) are more toxic than the organic ones (oAs).
Most of the human health effects of arsenic have been established based on epidemiologic studies,
which have shown a significant association between the consumption of arsenic through drinking
water and cancers of the skin, lung, bladder, liver, and kidney, neurologic disease, cardiovascular
disease, as well as other non-malignant diseases. Arsenic is not an essential element for plants and
its over-concentration in soils can generate toxicity phenomena. Its translocation from soil to plant
constitutes one of the main human exposure ways. In this research we evaluated the effects of As
exposure on Vicia faba seedlings by means of infrared (FTIR) and near infrared (FTNIR)
spectroscopy to investigate molecular modifications caused by the interactions of plant with As. Both
techniques showed relevant molecular modifications depending on As exposure. Molecular
modifications evidenced by FTIR spectroscopy were mainly related to modified structures involving
methyl groups of polysaccharides proteins and lipids, resulting better evidenced in meristem root
samples. However, seconds derivative FTIR spectra did not show modification of the secondary
structure of proteins.
The molecular modifications shown by FTNIR spectroscopy were mainly related to the bands of
hydroxyl groups with carboxylic and methyl groups, involving hydrogen bonds between
carbohydrates and nucleic acids and lipids. These molecular and structural modifications are
determined by the direct introduction of As within the plant biomolecules.

This research work has been focused in the study of gallinaceous feathers, a waste that may be
valorised as sorbent, to remove the Dark Blue Astrazon 2RN (DBA) from Dystar.
This study was focused on the following aspects: optimization of experimental conditions through
factorial design methodology, kinetic studies into a continuous stirred tank adsorber (at pH 7 and
20ºC), equilibrium isotherms (at pH 5, 7 and 9 at 20 and 45ºC) and column studies (at 20ºC, at pH 5,
7 and 9). In order to evaluate the influence of the presence of other components in the sorption of
the dyestuff, all experiments were performed both for the dyestuff in aqueous solution and in real
textile effluent.
The pseudo-first and pseudo-second order kinetic models were fitted to the experimental data, being
the latter the best fit for the aqueous solution of dyestuff. For the real effluent both models fit the
experimental results and there is no statistical difference between them. The Central Composite
Design (CCD) was used to evaluate the effects of temperature (15 - 45ºC) and pH (5 - 9) over the
sorption in aqueous solution. The influence of pH was more significant than temperature. The
optimal conditions selected were 45ºC and pH 9. Both Langmuir and Freundlich models could fit the
equilibrium data. In the concentration range studied, the highest sorbent capacity was obtained for
the optimal conditions in aqueous solution, which corresponds to a maximum capacity of 47± 4 mg g-1.
The Yoon-Nelson, Thomas and Yan’s models fitted well the column experimental data. The highest
breakthrough time for 50% removal, 170 min, was obtained at pH 9 in aqueous solution. The
presence of the dyeing agents in the real wastewater decreased the sorption of the dyestuff mostly
for pH 9, which is the optimal pH. The effect of pH is less pronounced in the real effluent than in
aqueous solution. This work shows that feathers can be used as sorbent in the treatment of textile
wastewaters containing DBA.

Olive oil mill solid residue (OMSR) is the solid waste generated during olive oil production process in
three-phase olive mills. It consists of the remaining pulp of olive processing after the extraction of oil,
as well as the cracked seeds of the olive fruits, containing thus mainly lignocellulose and residual oil.
The commonly used practice for OMSR management is combustion, after having extracted the
residual oil by secondary extraction using organic solvents. Other proposed ways of OMSR
management are their exploitation as substrate for edible fungi production and compost, and as
feedstock for biofuels generation such as methane and bioethanol. In the latter case, the complex
carbohydrates (cellulose and hemicellulose) of the lignocellulose of OMSR have to be degraded
towards their simple sugars and further fermented via microorganisms.
The purpose of the present study was to investigate the effect of thermochemical pre-treatment of
OMSR, on the final ethanol yield from the yeast Pachysolen tannophilus. Nine different types of
OMSR-based substrates were tested i.e. raw OMSR, hydrolysates generated from pretreated OMSR
with NaOH (0.5 %, 1.5 % w/v) and H2SO4 (0.5 %, 1.5 % v/v), and pretreated OMSR with NaOH (0.5 %,
1.5 % w/v) and H2SO4 (0.5 %, 1.5 % v/v) whole biomass. It was shown that in all cases pretreatment
enhanced the consumption of carbohydrates as well as ethanol final yields.

The aim of this study was to assess the feasibility of co-digesting lipids originated from domestic
wastewater along with sewage sludge. Three lab-scale single stage mesophilic anaerobic digesters
were operated under a constant hydraulic retention time (15 days). One system (C) was fed on a
daily basis with sewage sludge and served as the control system and its operation was compared
with two experimental systems (E1 and E2). Both experimental systems received mixtures of sludge
and lipids with different lipids content (20 % for system E1 and 60 % for system E2 on a VS basis),
whereas organic loadings were 2 KgVS m-3 d-1 and 3,5 KgVS m-3 d-1 for systems E1 and E2,
respectively.
According to the results it can be stated that the addition of lipids to sewage sludge up to 60 % on a
VS basis resulted in a significant increase of biogas production without producing any severe effects
on the properties of the digested sludge. More specifically biogas production of reactor E1 was 18 %
greater than that of reactor C, whereas biogas produced in reactor E2 was even greater (50 %
higher than that of reactor C). Finally it is interesting that during start-up a lag phase was recorded at
reactor E2 before biogas production initiated, which should be attributed to the time required for
growth of acetogenic bacteria capable to degrade LCFA.