**3.1 Influence of COD in raw effluents on the behavior and chlorophyll concentration in algae**

The presence of hormones in the effluent has significantly affected the velocity of surface ascent rate, since it was inhibited (**Figure 2**). The same was observed in the algae's r-value. The phenomenon was similar to the one observed by Pinto et al [8].

However, it is important to say the COD, unlike the original ED, presents a certain potential of chlorophyll degradation.

#### **Figure 1.**

*CGMS chromatogram showing ED absence after POA/UA for 120 minutes.*

#### **Figure 2.**

*Changes in behavioral parameters of Euglenas gracilis exposed to post-ozonating effluents at the Laboratory of Hormones, compared to the raw effluent. Pearson correlation test: There are significant connections between the pairs of variables (P > 0,050).*

To better comprehend this effect on chlorophyll degradation by COD, a comparison between the concentration before and after the ozonating process was performed (**Figure 3**). Considering the influence over the chlorophyll concentration, it was seen a clear difference between the laboratories and the pre- and post-ozonating, as it is possible to seen in **Figure 3**.

In this comparison, it was seen that in the solids and psychotropics laboratories there was reduction in *a*-chlorophyll in the presence of raw effluent. The result was very similar when compared with the same waste treated using ozonating. However, in the dermato-cosmetics laboratory, as well as in the LMH, it was difficult to see influence of raw effluent, but is was observed influence of the treated effluent, which now has a concentration similar to the ones from the other laboratories treated with ozone/UV. It is important to emphasize the ozone in excess was not present, because in reaction with potassium permanganate the result was negative for the ozone. The justification for the LHM was the antioxidating activity, while a probable explanation for the dermato-cosmetics was the small quantity of highly lipophilic products manipulated there, besides the little influence in the algae physiology [17].

Another relevant variable is the quantity of actives and substances disposed through the sinks and that compound the raw effluent of the laboratories.

For this purpose, the pharmacy's average monthly production of six months was taken into account, and the monthly average production was calculated, in order to verify the laboratories' pre-ozonating activity average. The results obtained accordingly Eq. (1) are presented in **Figure 4**.

The most impacting treated effluent that has COD, in an independent way, on *a*-chlorophyll concentration came from the laboratory of hormones, since it has the lowest production and significant reduction of *a*-chlorophyll concentration. At the same time, in the presence of raw effluent, its concentration was similar to the control one.

Then, it is clear that the removal process via ozone/UV, in the total estrogenic activity removal, interferes on *a*-chlorophyll degradation with COD. Both the raw effluent and the treated one influence on *a*-chlorophyll concentration, reducing it, except at LMH. The reduction of chlorophyll concentration might affect the algae's photosynthetic efficiency and cause ecotoxicity hazards, when there is not compensatory mechanism to assure the algae's survival. Anyway, the condition does not dispense the monitoring of effluents [18].

#### **Figure 3.**

*Influence on chlorophyll concentration. Variance analysis on Kruskal-Wallis variables. H = 7.812 with 2 liberty degrees. P (est.) = 0.020 P (exact) = 0.011. The difference among the average value between the treatment groups are greater than the expected. There is a statistically significant difference (P = 0.011).*

#### **Figure 4.**

*Influence of the produced quantity versus pre-ozonating chlorophyll concentration. Pearson correlation test: Alteration on chlorophyll concentration at the laboratory (P > 0,050).*

#### **Figure 5.**

*Comparison between chlorophyll concentration and global photosynthetic efficiency. Variance analysis on Kruskal-Wallis variables. H = 7.812 with 2 liberty degrees. P (est.) = 0.020 P (exact) = 0.011. The difference among the average value between the treatment groups are greater than the expected. There is a statistically significant difference (P = 0.011).*

Thus, considering the reduction of *a*-chlorophyll concentration was strongly influenced by the COD, it was also pursued if these reductions would interfere on the global photosynthetic efficiencies of the post-ozonating samples, in order to confirm if the chlorophyll concentration influence anyhow this physiologic parameter, denoting one more risk/environmental hazards (**Figure 5**).

The global photosynthetic efficiency has presented variations among the raw effluent samples, revealing a direct correlation between the chlorophyll concentration and the global photosynthetic efficiency in all the laboratories, except in the hormones one, in which the probable antioxidating action attributed to the steroidal hormone structure helps the electrons transference and contributes to the global photosynthetic efficiency improvement [8, 19].

The global photosynthetic efficiency was influenced by the COD in all laboratories, and the laboratory of hormones has showed the lowest value in the presence of COD and the highest difference between the efficiencies found in the exposure of raw effluents and the treated ones. The hormones' antioxidating activity has assured a good global photosynthetic efficiency performance. The reduction of

*Evaluation of the Use of Advanced Ozone Oxidative Process in Reducing the Danger… DOI: http://dx.doi.org/10.5772/intechopen.95068*

global photosynthetic efficiency after the ozonation occurred because the hormone decomposition and its oxidizing potential, as well as the possible ethylene formation, which affects the chlorophyll activity [20].

Regarding the solids and psychotropics laboratories, the global photosynthetic efficiency reduction was due to the presence of substances that act on action potentials, listed in the production of both laboratories. These changes may influence the algae's movement ability, being an extra factor on the global photosynthetic efficiency, or the reduction is only attributed to the decline on chlorophyll concentration.

Maybe, the potential cellular action attributed to the manipulated medicines in these laboratories prevent these mechanisms, which affect the algae's flagellar mobility [21].
