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The use of mercury in gold mining adversely affects the ecosystems and has raised concerns, especially in specific areas of Colombia. An alternative to the use of mercury involves using the mucilage of plant species for gold separation. Here we present the use of mucilage extracted from Theobroma cacao L pod husks. The coagulant agent can be obtained by: (i) cutting and macerating cocoa pod husks to obtain the mucilage, (ii) mixing the mucilage with water, and (iii) thermally treating the mucilage until a coagulant is obtained. This research showed that the coagulant agent from cocoa pod husks waste can replace mercury use in artisanal small-scale gold mining in Colombia. Our coagulant agent collects impurities, leaving the gold completely free, with a recovery percentage of 95%. Consequently, we can eliminate the use of mercury from the gold beneficiation process and thereby reduce water, soil, and air contamination. Additionally, by using solid waste as a coagulant agent, this becomes a successful case of circular economy. [ABSTRACT FROM AUTHOR]

Context: The use of natural coagulants for water clarification is being globally researched due to their low cost, high biodegradability, and ability to replace highly toxic synthetic coagulants. Knowledge gap: The water of the Ciénaga Grande (Great Swamp in English) in Atlantico Department, Colombia, is used for cleaning, consumption, and food preparation by the inhabitants of the area. However, it does not comply with water quality for human consumption, as defined by the Resolution 2115 of 2007 regarding the turbidity parameter. For this reason, it is important to analyze the synergy generated by using the coagulant combination of moringa seeds and cassava starch in the search to improve its conditions. It is important to note that there are few reports in the literature on the simultaneous use of these coagulants. Purpose: This research aims to evaluate the clarification of the water from Ciénaga Grande using mixtures of natural coagulants composed of moringa seeds and cassava starch to reduce its turbidity. Methodology: The combinations of coagulants, moringa seeds, and cassava starch, were mixed with a ratio of 90:10, 80:20, 70:30, and 60:40, respectively. The turbidity and pH of Ciénaga Grande water were evaluated. In addition, clarification was simulated in accordance with the regulation NTC 3903 of 2010 with each treatment. It began with agitation at 120rpm for 1 min., then an agitation at 30rpm was carried out for 20 min., and, finally, it was left to sediment for 15 min. Then, a sample was extracted from each jar, and the final turbidity was measured. A factorial design was carried out for each coagulant combination, with six dose levels (mg/L) and one response variable, the final water turbidity (nephelometric turbidity unit, NTU). The analysis of variance ANOVA and Duncan's multiple range test were carried out using 95% reliability. Results and conclusions: The treatment with the highest turbidity removal (NTU) was treatment 4, which has a 60:40 ratio of moringa seeds and cassava starch. Additionally, the turbidity parameter decreased by 80.4%. The doses used in treatments 1, 2, and 3 influenced the final turbidity of the water. It was concluded that high initial turbidity increases the coagulating activity of the natural mixture, causing a higher removal of such a parameter. [ABSTRACT FROM AUTHOR]

This study analyzed the effectiveness of banana and plantain (Musa paradisiaca L.) as coagulants-flocculants in the treatment of raw water from the Guatapurí River (Cesar region, Colombia). The experimental design was completely randomized. Coagulating solutions with banana and plantain as organic solute were evaluated to treat raw water with different initial turbidity, analyzing their effect on the elimination of dissolved solids that provide turbidity, electrical conductivity and alkalinity. The results showed a significant turbidity removal up to 86.8% (banana) and 84.1% (plantain) when applying 10 ppm of coagulant for an initial turbidity of 250 NTU. When applying doses of 5, 20, and 75 ppm in water with an initial turbidity of 576 NTU, a significant elimination of turbidity was achieved (banana = 99.3, 98.5 and 98.5%; plantain = 99.3, 98.3 and 98.4%). It is concluded that the coagulating solutions with plantain and banana solutes allowed to eliminate the turbidity of the raw water of the Guatapurí river. [ABSTRACT FROM AUTHOR]

Biochemical and biological differences in the venom of Crotalus durissus cumanensis from three ecoregions of Colombia were evaluated. Rattlesnakes were collected from the geographic areas of Magdalena Medio (MM), Caribe (CA) and Orinoquía (OR). All three regionally distributed venoms contain proteases, PLA2s and the basic subunit of crotoxin. However, only crotamine was detected in the CA venom. The highest lethality, coagulant, phospholipase A2 and hyaluronidase activities were found in the MM venom. Also, some differences, observed by western blot and immunoaffinity, were found in all three venoms when using commercial antivenoms. Furthermore, all three eco-regional venoms showed intraspecific variability, considering the differences in the abundance and intensity of their components, in addition to the activity and response to commercial antivenoms. [ABSTRACT FROM AUTHOR]

This research analyzed the efficiency of the banana pith as a coagulant substance in the clarification of natural waters and was compared with aluminium sulphate. It was used a factorial experimental design, being the dosage (10, 20, 40, 60, 80 and 100 mg/L) and the type of coagulant (chemical or natural) the factors. The turbidity of the Magdalena river water was used as a variable response. The clarification process was carried out by applying jar-test using water samples from the river in Barranquilla, Atlántico departament, Colombia. It was verified by the statistical analysis ANOVA and the Tukey's HSD (honestly significant difference) test, that the natural coagulant reduces the initial turbidity of the water object of study (210 NTU) in 67.57%. The banana pith being an agro-industrial waste is a viable and sustainable option in the partial removal of water turbidity in the Magdalena river. [ABSTRACT FROM AUTHOR]