Effect of the association of coagulation/flocculation, hydrodynamic cavitation, ozonation and activated carbon in landfill leachate treatment system.

Mature landfill wastewater is a complex effluent due to its low biodegradability and high organic matter content. Currently, mature leachate is treated on-site or transported to wastewater treatment plants (WWTPs). Many WWTPs do not have the capacity to receive mature leachate due to its high organic load leading to an increase in the cost of transportation to treatment plants more adapted to this type of wastewater and the possibility of environmental impacts. Many techniques are used in the treatment of mature leachates, such as coagulation/flocculation, biological reactors, membranes, and advanced oxidative processes. However, the isolated application of these techniques does not achieve efficiency to meet environmental standards. In this regard, this work developed a compact system that combines coagulation and flocculation (1st Stage), hydrodynamic cavitation and ozonation (2nd Stage), and activated carbon polishing (3rd Stage) for the treatment of mature landfill leachate. The synergetic combination of physicochemical and advanced oxidative processes showed a chemical oxygen demand (COD) removal efficiency of over 90% in less than three hours of treatment using the bioflocculant PGα21Ca. Also, the almost absolute removal of apparent color and turbidity was achieved. The remaining CODs of the treated mature leachate were lower when compared to typical domestic sewage of large capitals (COD ~ 600 mg L-1), which allows the interconnection of the sanitary landfill to the urban sewage collection network after treatment in this proposed system. The results obtained with the compact system can help in the design of landfill leachate treatment plants, as well as in the treatment of urban and industrial effluents which contains different compounds of emerging concern and persistence in the environment.

Effects of Avermectins on the Environment Based on Its Toxicity to Plants and Soil Invertebrates-a Review.

Avermectins are pharmaceutical drugs widely used mainly in livestock to combat both ectoparasites and endoparasites. Drugs belonging to this family include ivermectin, abamectin, doramectin, selamectin, eprinomectin, and emamectin benzoate, and they share similar chemical characteristics. When administered to livestock, between 80 and 98% of the drug is estimated to leave the body without being metabolized in feces, thus reaching the soil. For this reason, concern for avermectin contamination in soil is increasing, and researchers are focused on estimating the effects on non-target organisms, such as plants and soil invertebrates. This review aimed to compile and discuss updated data of avermectin toxicity on non-target organisms to better comprehend its effect on the environment. Effects on plants are scarcely studied, since they were not believed to absorb these drugs. However, recent studies suggest that plants can be negatively affected. Regarding soil invertebrates, negative effects such as increased mortality and reduced reproduction are best known to dung-beetles. Recently, some studies have also suggested that earthworms, springtails, and enchytraeids can be adversely affected by avermectin exposure. Since ivermectin was the first avermectin marketed, most of the data refers to this product. According to new data on scientific literature, avermectins can now be considered harmful to non-target organisms, and its prudent use is recommended in order to reduce negative effects on the environment. For future investigations, inclusion of avermectins other than ivermectin, as well as field and "omics" studies is suggested.

Environmentally realistic concentrations of eprinomectin induce phytotoxic and genotoxic effects in Allium cepa.

Eprinomectin, a veterinary drug within the family of avermectins, is widely used in the agricultural sector to combat a variety of parasites, mainly nematodes. However, only 10% of the drug is metabolized in the organism, so large quantities of the drug are released into the environment through urine and/or feces. Soil is the first and main environmental compartment to be contaminated by it, and nontargeted organisms can be affected. Thus, the present study aims to evaluate the phytotoxicity (through the evaluation of germination, root development, and germination speed) and genotoxicity (through an assessment of the induction of micronuclei and chromosomal aberrations) of eprinomectin. For the analyses, Allium cepa seeds were germinated in soil contaminated with a range of concentrations of eprinomectin: from 0.5 to 62.5 µg/g for the genotoxicity test and from 0.5 to 128.0 µg/g for the phytotoxicity test. The results showed that seed germination was not affected, but root development was affected at concentrations of 0.5 µg/g, 1.0 µg/g, 4.0 µg/g, 8.0 µg/g, 64.0 µg/g, and 128.0 µg/g, and germination speed was significantly changed at concentrations of 1.0 µg/g, 4.0 µg/g, 16.0 µg/g, 32.0 µg/g, and 64.0 µg/g. Significant differences in the mitotic index and genotoxicity index were observed only at concentrations of 2.5 µg/g and 12.5 µg/g, respectively. Only the 0.5 µg/g concentration did not show significant induction of micronuclei in the meristematic cells, but the damage observed at other concentrations did not persist in F1 cells. According to the results, eprinomectin is both phytotoxic and genotoxic, so the release of eprinomectin into the environment should be minimized.

Evaluation of residual antimicrobial activity and acute toxicity during the degradation of gatifloxacin by ozonation.

The concerns regarding the occurrence of pharmaceuticals in wastewater treatment plants have increased in the last decades. Gatifloxacin (GAT), the fourth generation of fluoroquinolones, has been widely used to treat both Gram-positive and Gram-negative bacteria and has a limited metabolization. The present study aimed to evaluate ozonation as a technique to degrade GAT. An exchange A UHPLC-MS/MS by an UHPLC-MS/MS method was used to quantify the residual of GAT and to assess its degradation products. The removal efficiency was higher under alkaline conditions (pH = 10), reaching up to 99% of GAT after 4 min. It was also observed that the first ozone attack on the GAT molecule was through the carboxylic group. In contrast, under acid conditions (pH = 3), the ozone attack was first to the piperazinyl ring. The antimicrobial activity was evaluated using Escherichia coli and Bacillus subtilis as test organisms, and it was observed that the residual activity reduced most under alkaline conditions. In contrast, the best condition to remove the residual toxicity evaluated for the marine bacteria V. fischeri was the acidic one. Due to this, ozonation seemed to be an exciting process to remove GAT in aqueous media.

SARS-CoV-2: a systematic review of indoor air sampling for virus detection.

In a post-pandemic scenario, indoor air monitoring may be required seeking to safeguard public health, and therefore well-defined methods, protocols, and equipment play an important role. Considering the COVID-19 pandemic, this manuscript presents a literature review on indoor air sampling methods to detect viruses, especially SARS-CoV-2. The review was conducted using the following online databases: Web of Science, Science Direct, and PubMed, and the Boolean operators "AND" and "OR" to combine the following keywords: air sampler, coronavirus, COVID-19, indoor, and SARS-CoV-2. This review included 25 published papers reporting sampling and detection methods for SARS-CoV-2 in indoor environments. Most of the papers focused on sampling and analysis of viruses in aerosols present in contaminated areas and potential transmission to adjacent areas. Negative results were found in 10 studies, while 15 papers showed positive results in at least one sample. Overall, papers report several sampling devices and methods for SARS-CoV-2 detection, using different approaches for distance, height from the floor, flow rates, and sampled air volumes. Regarding the efficacy of each mechanism as measured by the percentage of investigations with positive samples, the literature review indicates that solid impactors are more effective than liquid impactors, or filters, and the combination of various methods may be recommended. As a final remark, determining the sampling method is not a trivial task, as the samplers and the environment influence the presence and viability of viruses in the samples, and thus a case-by-case assessment is required for the selection of sampling systems.

Degradation of antidepressant pharmaceuticals by photoperoxidation in diverse water matrices: a highlight in the evaluation of acute and chronic toxicity.

Photoperoxidation (UV/H2O2) was used to degrade three of the worldwide most consumed antidepressant pharmaceuticals-bupropion, escitalopram, and fluoxetine-in ultrapure water, drinking tap water, surface water, and reclaimed water. The study was performed with antidepressants in concentration levels in which these compounds usually occur in the water matrices. Online solid-phase extraction coupled to UHPLC-MS/MS was used to quantify the analytes during degradation studies. The UV/H2O2 process was able to degrade bupropion and fluoxetine in ultrapure water, using 0.042 mmol L-1 of H2O2 and 1.9 kJ of UV-C irradiation. Nevertheless, escitalopram, which had the most recalcitrant character among the studied antidepressants, needed a tenfold more oxidant and UV-C irradiation. The primary metabolites of the antidepressants were identified as the major by-products generated by the UV/H2O2 process, and they persisted in the solution even when the parent compound was degraded. The residual toxicity of the solution was evaluated for two different trophic levels. The UV/H2O2 process reduced the toxicity of the solution to Raphidocelis. subcapitata microalgae after 30 min of reaction. On the other hand, the toxicity of the residual solution increased over the reaction time to the marine bacteria Vibrio fischeri (reaching up to 48.3% of bioluminescence inhibition after 60 min of reaction). Thus, our results evidenced that the toxicity against different trophic levels and the monitoring of the by-products formed are important aspects to be considered regarding the safety of the treated solution and the optimization of the treatment process.

Sulfaquinoxaline Oxidation and Toxicity Reduction by Photo-Fenton Process.

Sulfaquinoxaline (SQX) has been detected in environmental water samples, where its side effects are still unknown. To the best of our knowledge, its oxidation by Fenton and photo-Fenton processes has not been previously reported. In this study, SQX oxidation, mineralization, and toxicity (Escherichia coli and Staphylococcus aureus bacteria) were evaluated at two different setups: laboratory bench (2 L) and pilot plant (15 L). The experimental design was used to assess the influence of the presence or absence of radiation source, as well as different H2O2 concentrations (94.1 to 261.9 mg L-1). The experimental conditions of both setups were: SQX = 25 mg L-1, Fe(II) = 10 mg L-1, pH 2.8 ± 0.1. Fenton and photo-Fenton were suitable for SQX oxidation and experiments resulted in higher SQX mineralization than reported in the literature. For both setups, the best process was the photo-Fenton (178.0 mg L-1 H2O2), for which over 90% of SQX was removed, over 50% mineralization, and bacterial growth inhibition less than 13%. In both set-ups, the presence or absence of radiation was equally important for sulfaquinoxaline oxidation; however, the degradation rates at the pilot plant were between two to four times higher than the obtained at the laboratory bench.

Degradation of benzimidazoles by photoperoxidation: metabolites detection and ecotoxicity assessment using Raphidocelis subcapitata microalgae and Vibrio fischeri.

Benzimidazoles (BZ) are among the most used drugs to treat parasitic diseases in both human and veterinary medicine. In this study, solutions fortified with albendazole (ABZ), fenbendazole (FBZ), and thiabendazole (TBZ) were subjected to photoperoxidation (UV/H2O2). The hydroxyl radicals generated by the process removed up to 99% of ABZ, and FBZ, in the highest dosage of H2O2 (i.e., 1.125 mmol L-1; 4.8 kJ L-1). In contrast, 20% of initial TBZ concentration remained in the residual solution. In the first 5 min of reaction (i.e., up to 0.750 mmol L-1 of H2O2), formation of the primary metabolites of ABZ-ricobendazole (RBZ), albendazole sulfone (ABZ-SO2), and oxfendazole (OFZ)-was observed. However, these reaction products were converted after the reaction time was doubled. The residual ecotoxicity was investigated using the Raphidocelis subcapitata microalgae and the marine bacteria Vibrio fischeri. The results for both microorganisms evidence that the residual solutions are less harmful to these microorganisms. However, after 30 min of reaction, the treated solution still presents a toxic effect for V. fischeri, meaning that longer reaction times are required to achieve an innocuous effluent.

Removal of the antimicrobial activity from fortified effluents with fluoroquinolones by photocatalytic processes: a comparative study of differently synthesized TiO2-N.

This study presents a comparison of three methods for TiO2-N synthesis that were applied in the photocatalytic oxidation of the fluoroquinolones (FQs) ciprofloxacin, ofloxacin, and lomefloxacin in aqueous solution. The TiO2-N bandgap is small enough to allow the use of solar energy in the photocatalytic oxidation (PCO) reactions. The TiO2 doped by a sol-gel method with titanium butoxide (TiO2-N-BUT) and titanium isopropoxide (TiO2-N-PROP) as the precursor were effective as the TiO2 (P25) impregnation with urea (TiO2-N-P25) to degrade the FQs. The FQ degradation was higher by 74, 65, and 91%, respectively for TiO2-N-BUT, TiO2-N-PROP, and TiO2-N (load 50 mg L-1, 20 min of reaction under 28 W UV-ASolar). The TiO2-P25 with urea showed the best performance in FQ degradation. The reaction intermediates might present modifications in their acceptor groups by PCO and, because of that the antimicrobial activity dropped as the reaction time increased. Reactions with TiO2-N-P25 (100 mg L-1) and TiO2-N-BUT (100 mg L-1) achieved ≥ 80% of antimicrobial activity removal from the mixed FQ solution (Cciprofloxacin = 100 µg L-1; Cofloxacin = 100 µg L-1; Clomefloxacin = 100 µg L-1) after 40 min of reaction, for both for Escherichia coli and Bacillus subtilis.

Pre-ozonation of surface water: An effective water treatment process to reduce the risk of infection by Giardia in drinking water.

Giardia is a protozoan parasite of primary concern for the drinking water industry. High contact times are required for Giardia inactivation by chlorination, while ozonation may be effective at much lower Ct products. In this study, we have assessed the occurrence of Giardia cysts in raw water, and in chlorinated or ozonated water from a drinking water treatment plant (DWTP) in Brazil, over a 16-month period. Moreover, we analyzed the effects of primary disinfection on cysts, and calculated the infection risk caused by the occurrence of Giardia cysts in raw water, chlorinated or ozonated water. Furthermore, we assessed the correlation of Giardia cysts with indicator bacteria in raw water. Data referring to concentration of Giardia cysts in raw water showed adherence to a gamma distribution at a significance level α = 0.05. The detection frequency and the mean concentration of Giardia cysts were higher in raw water (86.6%, 26 cysts∙L-1), than in chlorinated (46.1%, 15.7 cysts·L-1) or ozonated water (43.5%, 11.1 cysts·L-1). Overall, Giardia non-viable cysts were detected more frequently in ozonated water (80%) than in chlorinated water (68.2%) or raw water (37.7%). Ozonation and chlorination resulted, respectively, in ≈27.5- and ≈13- fold reduction of Giardia infection risk, when compared to the risk calculated for raw water. Total coliform and Escherichia coli proved to be suitable surrogates to predict the occurrence of Giardia cysts in raw surface water, however, the indicator bacteria may not be suitable surrogates to predict the disinfection of Giardia cysts, as no correlation was found between indicator bacteria and Giardia cysts in treated water. To our knowledge, this is the first study reporting the efficacy of chlorine and ozone at Ct products actually applied at a full-scale drinking water treatment plant against Giardia cysts naturally occurring in the source water, i.e. real situation. Ozonation has proven more efficient than chlorination against Giardia cysts in surface water. Escherichia coli proved to be suitable surrogate to predict Giardia cysts in raw surface water.

Advanced oxidation processes on doxycycline degradation: monitoring of antimicrobial activity and toxicity.

Advanced oxidation processes (AOPs) have been highly efficient in degrading contaminants of emerging concern (CEC). This study investigated the efficiency of photolysis, peroxidation, photoperoxidation, and ozonation at different pH values to degrade doxycycline (DC) in three aqueous matrices: fountain, tap, and ultrapure water. More than 99.6% of DC degradation resulted from the UV/H2O2 and ozonation processes. Also, to evaluate the toxicity of the original solution and throughout the degradation time, antimicrobial activity tests were conducted using Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacteria, and acute toxicity test using the bioluminescent marine bacterium (Vibrio fischeri). Antimicrobial activity reduced as the drug degradation increased in UV/H2O2 and ozonation processes, wherein the first process only 6 min was required to reduce 100% of both bacteria activity. In ozonation, 27.7 mg L-1 of ozone was responsible for reducing 100% of the antimicrobial activity. When applied the photoperoxidation process, an increase in the toxicity occurred as the high levels of degradation were achieved; it means that toxic intermediates were formed. The ozonated solutions did not present toxicity.

Pre-ozonation of source water: Assessment of efficacy against Giardia duodenalis cysts and effects on natural organic matter.

The protozoan Giardia duodenalis is one of the parasites of primary concern in drinking water treatment plants, due to its resistance to chlorination. Another matter of concern regarding chlorination of drinking water is the formation of disinfection by-products in the presence of precursors such as natural organic matter (NOM). In this study, the effects of ozonation (5 mg L-1) on G. duodenalis cysts in raw surface water from a drinking water treatment plant were evaluated, and the presence and alteration of NOM were assessed, as an indicative of the potential to prevent total organic halogen (TOX) formation during post-chlorination. Following ozone treatment, the presence of damaged cysts was observed by direct immunofluorescence assay (IFA) and confirmed by the molecular approach propidium monoazide-polymerase chain reaction (PMA-PCR). Using an animal model, analysis of the intestinal tissues revealed that 80% of the animals inoculated with ozonated water were positive for trophozoites. This study shows that analysis of intestinal fragments is imperative to accurately assess animal infection following inoculation of treated cysts. More importantly, considering the low infective dose of Giardia cysts in susceptible hosts, an ozone dosage usually applied in drinking water treatment plants did not completely inactivate G. duodenalis cysts in surface water. Nonetheless, the results suggest that competitive reactions with NOM have occurred, and the applied ozone dosage has proven useful to remove NOM reactivity, and thus prevent halogenated DBP formation during post-chlorination.

Photocatalytic removal of fluoroquinolones and their antimicrobial activity from water matrices at trace levels: a comparison of commercial TiO2 catalysts.

In this study, a solution containing the fluoroquinolones (FQs) ciprofloxacin, lomefloxacin, and ofloxacin (antimicrobial agents) was subjected to photocatalytic oxidation under UVA irradiation, employing the commercial titanium dioxide as catalyst. On-line solid phase extraction coupled to ultra-high-performance liquid chromatography-mass spectroscopy was used to pre-concentrate and quantify the analytes. The process provided an almost 95% degradation efficiency for all the FQs. The TiO2 PC500 (100% anatase) was more efficient than TiO2 P25 (80% anatase) for FQs degradation. The matrix effect on the efficiency of the process was evaluated by ultrapure water - UW, simulated water - SW, bottled water -BW, and public drinking tap water - TW. Simulated water showed lower interference, compared to drinking water and bottled mineral water, due to the lower concentrations of hydroxyl radical scavengers. The assessment of the residual antimicrobial activity in the solution, when using 50 mg L-1 PC500 or 100 mg L-1 P25, showed reductions of biological activity (after 120 min of reaction) of 92.4% and 95.4% for Escherichia coli, and 78.1% and 84.2% for Bacillus subtilis, respectively. It shows that the photocatalytic oxidation process was able to not only degrade the FQs but also deactivate its biological activity in the resultant solution.

Abatement and toxicity reduction of antimicrobials by UV/H2O2 process.

Antimicrobials are continuously detected in environmental waters and their removal is important to avoid health and microorganisms damage. In this work, the peroxidation assisted by ultraviolet radiation (UV/H2O2) was studied to verify if the process was able to degrade sulfaquinoxaline and ofloxacin antimicrobials and to remove the toxicity and the antimicrobial activity of the solution. This process was effective on degradation of the antimicrobials, despite the antimicrobial activity removal, the toxicity of the solution increased throughout the reaction time.

Antimicrobial activity and acute toxicity of ozonated lomefloxacin solution.

Lomefloxacin (LOM) is a synthetic antimicrobial from the fluoroquinolone family (FQ) used as a veterinary and human drug. Once in the environment, LOM may pose a risk to aquatic and terrestrial microorganisms due to its antimicrobial activity. This study evaluated the effect of ozonation of LOM (500 µg L-1), the residual antimicrobial activity against Escherichia coli and acute toxicity against Vibrio fischeri. In addition, degradation products were investigated by UHPLC-MS/MS and proposed. Ozonation was carried out varying the applied ozone dose from 0 to 54.0 mg L-1 O3 and pH values of 3, 7, and 11. Ozonation was most efficient at pH 11 and led to 92.8% abatement of LOM in a 9-min reaction time (54.0 mg L-1 O3 applied ozone dose). Ozonation at pH 3 was able to degrade 80.4% of LOM. At pH 7, 74.3% of LOM was degraded. Although the LOM concentration and the antimicrobial activity of the solution dropped as ozone dose increased (antimicrobial activity reduction of 95% at pH 11), toxicity to V. fischeri increased for pH 7 and 11 (i.e., 65% at pH 7 and 75% at pH 11). The reduction in antimicrobial activity may be related to the oxidation of piperazinyl and the quinolone moiety. The formation of intermediates depended on the oxidant (hydroxyl radicals or/and molecular O3) that acted the most in the process.

Antimicrobial activity against Gram-positive and Gram-negative bacteria during gatifloxacin degradation by hydroxyl radicals.

Gatifloxacin, an antimicrobial drug belonging to the fluoroquinolone family, is active against Gram-positive and Gram-negative bacteria and is extensively used for the control of infections in humans. The presence of the drug in environmental matrices has already been reported. This study investigated the degradation of gatifloxacin in water by hydroxyl radicals generated by the UV254 nm/H2O2 process ([Formula: see text] 0.4-2.4 mmol L-1) and evaluated the capacity of the radicals to reduce the antimicrobial activity against Gram-positive and Gram-negative bacteria. Acute toxicity assays were performed with Vibrio fischeri, and the degradation products were proposed. The hydroxyl radicals formed in the processes were able to degrade the fluoroquinolone and remove the antimicrobial activity from the aqueous solution. Approximately 97 % gatifloxacin degradation was observed after applying 2.4 mmol L-1 of initial H2O2 concentration and 20 min of UVC254nm irradiation (130 J s-1). The acute toxicity assays showed that the toxicity of the treated solution for V. fischeri increased as the gatifloxacin concentration in the solution decreased.

Influence of pH and ozone dose on sulfaquinoxaline ozonation.

Sulfaquinoxaline (SQX) is an antimicrobial of the sulfonamides class. Usually employed in veterinary medicine, this contaminant of emerging concern has been found in superficial and groundwater and its consequences for the environment and human health are not completely known. In this study, SQX (C0 = 500 µg L-1, 1 L) degradation by an ozonation process at pH 3, 7, and 11 was evaluated. Ozonation was effective in degrading SQX: efficiency exceeding 99% was obtained applying an ozone dose of 2.8 mg L-1 at pH 3. Assays were performed according to a 22 design of experiments (DOE) with star points and three central points for statistical validity. Minimum and maximum levels were set at 3 and 11 for pH, and 0 and 11.5 mg L-1 for applied ozone dose. There was no significant interaction between these variables, and the pH value played the most important role in terms of contaminant degradation. In relation to toxicity, samples ozonated at pH 3 did not inhibit the luminescence of the bacteria, even though different intermediates were formed and identified by mass spectra. At pH 7, inhibition of luminescence remained almost constant (at around 30%) according to ozonation time or ozone dose. However, the hydroxyl radical, the major oxidant at pH 11, was responsible for the formation of toxic intermediates.

Ammonia removal from landfill leachate by struvite formation: an alarming concentration of phosphorus in the treated effluent.

This study examined the removal of ammonia nitrogen from the leachate of a landfill site using the chemical precipitation of struvite (MgNH4PO4.6H2O). This procedure achieved a reduction in the ammonia concentration that was higher than 99% when the molar ratio of 1.8:1.0:1.4 for Mg2+:NH4+:PO43- was adopted. The metal concentration found in the precipitate formed was lower than the limits set by Brazilian and American regulations (CONAMA 375/2006 and US EPA, 40 CFR 503.1993). This demonstrates the potential use for this practice in agriculture. However, the effluent obtained from the tests presented a phosphorus concentration higher than the one in the raw leachate. This shows that removing this compound from the effluent must be further studied. Otherwise, adopting the chemical precipitation of ammonia by the formation of struvite may become unfeasible.

Ciliated protozoa community of a combined UASB-activated sludge system in southeastern Brazil.

The aims of the present study were (1) to evaluate the abundance and taxonomic composition of ciliated protozoa in the activated sludge of a full-scale combined anaerobic-aerobic system operating in a tropical country and (2) to study the relationship between the effluent quality, the physicochemical variables, and the ciliates present in the operating system. The total ciliate fauna of the activated sludge of the Piçarrão Wastewater Treatment Plant (Piçarrão WWTP) was composed of 36 morphospecies belonging to 33 genera. These included 21 species observed in the activated sludge samples on the day of collection and 15 species found in cultures. The activated sludge of the Piçarrão WWTP contained a diversified ciliate community composed mainly of indicator organisms. The most frequently occurring morphospecies were Aspidisca cicada, Vorticella spp., Gastronauta aloisi, Acineria uncinata, and Epistylis plicatilis complex. These results showed that satisfactory operating conditions prevailed at the Piçarrão WWTP. In the combined UASB-activated sludge system, the presence of Aspidisca cicada suggests the occurrence of denitrification in the process while the presence of Acineria uncinata and G. alosi indicates the removal of carbonaceous organic matter.

Fate of ivermectin in the terrestrial and aquatic environment: mobility, degradation, and toxicity towards Daphnia similis.

Ivermectin (IVM) is a broad-spectrum antiparasitic drug that is regularly employed in veterinary medicine. In this work, the sorption and desorption of IVM in two Brazilian soils (N1-sand and S2-clay) as well as its leaching capacity, dissipation under aerobic conditions, and degradation in aqueous solution by photocatalysis with TiO2 in suspension were evaluated. The kinetic sorption curves of IVM were adjusted to a pseudo-second-order model. The sorption and desorption data were well fitted with the Freundlich isotherms in the log form (r > 0.96). The Freundlich sorption coefficient (K F (ads) ) and the Freundlich desorption coefficient (K F (des) ) were 77.7 and 120 µg(1-1/n) (cm(3))(1/n) g(-1) and 74.5 and 138 µg(1-1/n) (cm(3))(1/n) g(-1), for soils N1 and S2, respectively. A greater leaching capacity of IVM was observed for the sandy soil N1 than for the clay soil S2. Under aerobic conditions, the dissipation (DT50) at 19.3 °C was 15.5 days (soil N1) and 11.5 days (soil S2). Photocatalysis with UVC and TiO2 in suspension resulted in the degradation of 98 % of IVM (500 µg L(-1)) in water in 600 s. The toxicity (Daphnia similis) of the solutions submitted to the photocatalytic process was completely eliminated after 10 min.