Browsing by Author "Buleje-Del-Carpio, Robert"

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Assessment of tannery effluents quality treated by electrocoagulation and ozonation: Physicochemical and ecotoxicological characterization
(Public Library of Science (PLoS), 2025-07-22) Aguilar-Ascón, Edwar; Marrufo-Saldaña, Liliana del Rosario; Barra-Hinojosa, Julio Alexis; Buleje-Del-Carpio, Robert
Tannery effluents are characterized by their high toxicity and complex pollutant load, posing significant risks to aquatic ecosystems. Although conventional treatment processes often achieve regulatory standards for pollutant concentrations, they do not necessarily guarantee the reduction of effluent toxicity. This study aimed to evaluate the quality of tannery effluents treated by electrocoagulation (EC) and the combined electrocoagulation-ozonation (ECO) process, while analyzing the associated toxicity reduction, in order to determine the suitability of these technologies for application and ensure environmental protection of receiving water bodies. For this purpose, tannery wastewater was treated sequentially using an electrocoagulation reactor followed by an ozonation system, yielding three sample types: raw (C), electrocoagulation-treated (EC), and electrocoagulation-ozonation treated (ECO). Physicochemical parameters were measured, toxicity was assessed through bioassays with Lactuca sativa and Eisenia fetida, and chemical changes were analyzed using FTIR spectroscopy. EC achieved 96.4% removal of total suspended solids (TSS), 30.9% of chemical oxygen demand (COD), and 99% of chromium, while ozonation further removed 10% of COD and 99% of sulfides. Toxicity assays indicated a reduction from 23.89 toxicity units (TUs) in the raw effluent to 8.32 TUs after EC and 11.12 TUs after ECO. The slight increase in toxicity after ozonation was associated with elevated ammoniacal nitrogen levels and the formation of new functional groups, as evidenced by the FTIR spectrum. Despite significant pollutant removal, the results highlight that treated effluents may still present residual toxicity, emphasizing the need for complementary treatment strategies to achieve true environmental safety.
Determination of the Tolerant Concentration of Eisenia fetida to Chrome Solid Residues from Tannery
(Leather and Footwear Research Institute (INCDTP-ICPI), 2020-12-15) Buleje-Del-Carpio, Robert; Marrufo-Saldaña, Liliana del Rosario
The tanning industry, although it is characterized by the use of the skin waste originated by the cattle raising, in contrast, produces huge volumes of waste, among which chrome shavings stand out due to their high percentage of chromium. The objective of this research was to determine the concentration where earthworms (Eisenia fetida) could tolerate chrome shavings, in order to evaluate the potential for degradation of these wastes through biological treatment. To determine the tolerant concentration, an experimental design was established that included as factors, the time of exposure in weeks (0-11) and the concentrations of exposure: 0.01, 0.02, 0.04, 0.08, 0.12 and 0.16 grams of shavings per grams of substrate. The response variable was the mortality rate. Each treatment was performed in triplicate and a negative control was included. Statistical treatment was performed using ANOVA and multiple comparison tests at 95% confidence with the statistical complement Real Statistics, Statgraphics and Yupana software. The tolerant concentration established in the study was 0.04 g/g (grams of shavings per grams of substrate) which is equivalent to 636 mg/kg (based on dry weight) expressed in weight of chrome per weight of compost.
Estimation of the Allowable Concentration of Chlorides in Soaking Effluents from the Tanning Process Using Ecotoxicological Tools
(Leather and Footwear Research Institute (INCDTP-ICPI), 2020-12-15) Mogollon-Ropa, Ruth; Marrufo-Saldaña, Liliana del Rosario; Barra-Hinojosa, Julio Alexis; Contreras-Panizo, Rosa; Buleje-Del-Carpio, Robert
The use of sodium chloride for the preservation of pelts and skins destined for tanning is a very widespread technique in Peru, therefore the quantities used of this salt represent high concentrations of chlorides in the liquid effluents that are generated, which can affect the environmental quality of ecosystems and human health. The present study aimed to estimate an allowable concentration of chlorides in tanning effluents using ecotoxicological tools so that it would serve as a guide for the tanning industry and the authorities in their efforts to establish better conservation practices and effluent control parameters, which are currently absent from national environmental legislation. The permissible concentration of chlorides was determined using bioassays with seeds of Lactuca sativa species (lettuce), which was exposed to soaking effluents obtained from local tanneries. The studied species was determined based on sensitivity tests to zinc sulfate (ZnSO4) applied to three commercial lettuce species. The selected lettuce seed presented a germination rate higher than 90%, a CV lower than 30% and an IC50 of 38.97 mg/L of Zn+2 with a confidence interval between 19.30 mg/L and 58.65 mg/L of Zn+2. The admissible guide concentration determined for chlorides in soaking effluents from IC50 was 582.30 mg/L with a minimum value of 258.45 mg/L and a maximum of 906.15 mg/L. Additionally, because of the presence of other pollutants in the soaking effluents, such as bactericides, organic matter, enzymes and salts added in soaking process, tests with synthetic solutions of sodium chloride at the same concentrations of the soaking effluents were conducted, to evaluate the effect produced by those substances.