368
8.4.4 Treatment of Organic Substances and Metals Present
in Industrial Discharge Waters
It is extremely difficult to remove pollutants present at low concentrations in industrial discharge waters (Badot et al. 2007; Crini and Badot 2008). For this purpose, a
sequential dual approach can be considered: firstly, adsorption onto commercial
activated carbon to remove organics, e.g., oils, solvents, and organic load, combined
with ion exchange by means of commercial organic resins to remove inorganic pollutants, e.g., metals and anions such as fluorides (Sancey et al. 2010, 2012; Crini
2015a). At the industrial scale, this type of sequence is acknowledged for its efficiency. However, it is an approach to water treatment that combines two methods of
separation using two distinct commercial materials. Materials capable of combining
the two functions are not yet available (Morin-Crini et al. 2019b).
With the exception of a few works, studies of real applications using cyclodextrin polymers are rare (Vélaz et al. 2007; Romo et al. 2008; Jurecska et al. 2014;
Nagy et al. 2014; Crini et al. 2019b; Fenyvesi et al. 2020). Thanks to industrial
grants and a French-Romanian research program, at the end of the 2000s, our group
carried out the first pilot studies demonstrating that a single ECP with amphoteric
and ion-exchange properties material could replace two conventional adsorbents
(activated carbon and resins) to effectively treat multi-contaminated effluent (Sancey
et al. 2010, 2011a, b, 2012; Sancey and Crini 2012). Coupled with an advanced
oxidation preliminary step, adsorption on ECP materials was efficient for the treatment of water with multiple inorganic (e.g., metals, boron, fluoride) and organic
(e.g., polycyclic aromatic hydrocarbons, volatile organic compounds, chlorophenols, and alkylphenols) contaminants both from a chemical and from an environmental point of view. The proposed process combined the advantages of oxidation
(i.e., mineralization and/or degradation of part of the organic substances) with those
of adsorption (i.e., physisorption and chemisorption of the pollutants by the crosslinked framework of the cyclodextrins). After use, the materials could be eliminated
by incineration, thus avoiding the need for fastidious and expensive regeneration.
This is the first time that such systems were able to treat both so-called emerging
pollutants such as chlorophenols and alkylphenols and conventional pollutants such
as metals, present in trace amounts in industrial effluents. We were talking about
two-in-one materials (Sancey and Crini 2012), a term coined by Professor French in
the 1950s and taken up by Professors Casu and Szejtli in the 1960s and 1980s,
respectively (Crini 2014).
In the early 2010s, our group proposed biomonitoring tests with plants or animals used as bioindicators to determine and compare the toxicity of industrial effluent from wood, pulp and paper, textile, and surface treatment industries before and
after treatment with an ECP material (Sancey et al. 2010, 2011a, b, c, 2012; Charles
et al. 2010). For example, to evaluate the usefulness of this process, bioassays based
on lettuce seed germination (Lactuca sativa L.) were proposed for the first time. The
results showed that, after treatment, the impact on lettuce germination was significantly reduced, thanks to the reduction in effluent toxicity. These phytotoxicty tests
G. Crini
8.4.4 Treatment of Organic Substances and Metals Present
in Industrial Discharge Waters
It is extremely difficult to remove pollutants present at low concentrations in industrial discharge waters (Badot et al. 2007; Crini and Badot 2008). For this purpose, a
sequential dual approach can be considered: firstly, adsorption onto commercial
activated carbon to remove organics, e.g., oils, solvents, and organic load, combined
with ion exchange by means of commercial organic resins to remove inorganic pollutants, e.g., metals and anions such as fluorides (Sancey et al. 2010, 2012; Crini
2015a). At the industrial scale, this type of sequence is acknowledged for its efficiency. However, it is an approach to water treatment that combines two methods of
separation using two distinct commercial materials. Materials capable of combining
the two functions are not yet available (Morin-Crini et al. 2019b).
With the exception of a few works, studies of real applications using cyclodextrin polymers are rare (Vélaz et al. 2007; Romo et al. 2008; Jurecska et al. 2014;
Nagy et al. 2014; Crini et al. 2019b; Fenyvesi et al. 2020). Thanks to industrial
grants and a French-Romanian research program, at the end of the 2000s, our group
carried out the first pilot studies demonstrating that a single ECP with amphoteric
and ion-exchange properties material could replace two conventional adsorbents
(activated carbon and resins) to effectively treat multi-contaminated effluent (Sancey
et al. 2010, 2011a, b, 2012; Sancey and Crini 2012). Coupled with an advanced
oxidation preliminary step, adsorption on ECP materials was efficient for the treatment of water with multiple inorganic (e.g., metals, boron, fluoride) and organic
(e.g., polycyclic aromatic hydrocarbons, volatile organic compounds, chlorophenols, and alkylphenols) contaminants both from a chemical and from an environmental point of view. The proposed process combined the advantages of oxidation
(i.e., mineralization and/or degradation of part of the organic substances) with those
of adsorption (i.e., physisorption and chemisorption of the pollutants by the crosslinked framework of the cyclodextrins). After use, the materials could be eliminated
by incineration, thus avoiding the need for fastidious and expensive regeneration.
This is the first time that such systems were able to treat both so-called emerging
pollutants such as chlorophenols and alkylphenols and conventional pollutants such
as metals, present in trace amounts in industrial effluents. We were talking about
two-in-one materials (Sancey and Crini 2012), a term coined by Professor French in
the 1950s and taken up by Professors Casu and Szejtli in the 1960s and 1980s,
respectively (Crini 2014).
In the early 2010s, our group proposed biomonitoring tests with plants or animals used as bioindicators to determine and compare the toxicity of industrial effluent from wood, pulp and paper, textile, and surface treatment industries before and
after treatment with an ECP material (Sancey et al. 2010, 2011a, b, c, 2012; Charles
et al. 2010). For example, to evaluate the usefulness of this process, bioassays based
on lettuce seed germination (Lactuca sativa L.) were proposed for the first time. The
results showed that, after treatment, the impact on lettuce germination was significantly reduced, thanks to the reduction in effluent toxicity. These phytotoxicty tests
G. Crini