Browsing by Author "Buleje Del Carpio, Robert"

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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
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; Barra Hinojosa, Julio; 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.