Comparison of the Optimization of the Coagulation-Flocculation and Electrocoagulation Treatment of Slaughterhouse Wastewater Using the Response Surface Method

In this work, the coagulation-flocculation and electrocoagulation treatments were compared in the removal of pollutants from wastewater from the Conchucos slaughterhouse, Lima. For the coagulation-flocculation treatment, we worked with 4 independent variables with their respective experimental ranges, coagulant dose (600-1000 mg / L), flocculant dose (4-8 mg/L), fast stirring speed (250-350 rpm), slow stirring speed (80-100 rpm), for electrocoagulation the parameters of stirring speed (250-350 rpm) and stirring time (15-30 rpm). The central compound design method (DCC) optimizing by response surface (RSM) was used as an experimental method for the reduction of pollutants as a function of chemical oxygen demand (% COD), a jar test equipment was used for the coagulation-flocculation and a one-liter shaker with aluminum plate electrodes at 30 V. The results show that coagulation/flocculation and electrocoagulation presented statistical models with F-values of 5.33, 20.30, significance p<0.05, with adjustments of R2 of 0.6179, and 0.7571 for an optimal arrangement with %COD reduction prediction, respectively. The electrocoagulation treatment presented a reduction of 75.43% similar to the predicted model, of the 2 treatments compared, the electrocoagulation is below the maximum admissible values (VMA) in COD, BOD and Oils and Fats, complying with the necessary parameters for the discharge to the sewerage system. &nbsp

Edible Mushroom, an Ecosystem Service of Pine Forests (Pinus Radiata): A Study of the Communities Cuyuni and Yuracmayo (Cusco, Peru)

The present study aims to identify and quantify the edible mushroom with high production value in Pinus radiata forests, and their natural production as an ecosystem service for the peasant communities of Cuyuni and Yuracmayo in the district of Ccatca (Cusco, Peru). Fifty fungal samples were collected according to cap diameter (10 cm, 15 cm and 20 cm), for counting and taxonomic identification. The samples were collected in 5 Pinus radiata forests with different growth ages (forest younger than 3 years, between 4 to 7 years and older than 7 years). The edible fungal species identified were Laccaria laccata and Suillus luteus, both in symbiotic growth with Pinus radiata, the latter being the most representative species due to its abundance and usefulness food, which gives it a high commercial value. The non-parametric Kruskal-Wallis test of SPSS software was used and determined that there is a statistical difference between different groups of the Suillus luteus and Pinus radiata forests with different growth ages. For example, it presents a higher average growth rate in Pinus radiata forests older than 7 years with an average production rate of 523.6 kg in fresh weight per harvesting season. However, there is also a homogeneity of the Suillus luteus species in all the Pinus radiata forests. Therefore, this type of fungus represents the most productive edible mushroom component for the Cuyuni and Yuracmayo communities. &nbsp

Immobilization of Lead by Phosphated Biochar Produced from Fish Farming Sludge and Sewage Sludge in a Contaminated Urban Soil

An evaluation was conducted on the application of phosphate biochar produced from Sewage Sludge (SS) of a Wastewater Treatment Plant (WWTP) for lead immobilization in contaminated soils of the Human Settlement (HS) Virgin of Guadalupe, in the district of Mi Peru. Biochar was generated by a slow pyrolysis process at 500°C. The biochar was dosed at 10% biochar/soil on lead-contaminated soil, and the factors studied were the type of biochar and time of application. A complete factorial design was performed, and the data were processed using Design Expert v11 software. The results showed that the maximum lead immobilization was 50.83% for BSS for 20 days at a dose of 10% biochar/soil. According to the factorial model, an R² of 0.85, an adjusted R² of 0.83, an F-value of 79.64, and p-values lower than 0.05 (95%) were obtained, indicating that the factor (F2) of application time is significant for the treatment. It was concluded that both types of sludge have the potential for lead immobilization in contaminated soil, and the application time is significant for lead immobilization

Application of Factorial Design for the Optimization of Pleurotus Afin Ostreatus Production Using Grass As Substrate

The organic residue from gardens, which is generally not used efficiently, has been the central focus of this research work. That is why the present work used the factorial methodology in the optimization of the production of Pleurotus afín ostreatus using an organic residue, with the primary objective of using this organic residue as a substrate, adjusting it through the balance of the C/N ratio, for the specific cultivation of Pleurotus. This is one of the edible mushroom species worldwide, known for its mycelial biomass and bioactive components. The methodology comprised several stages, including propagation of the fungus, generation of seeds using barley grains, inoculation with 5% inoculum in polypropylene bags containing four different types of substrates, with five replicates for each variant. The resulting production was measured, and the nutritional analysis of the fruiting bodies obtained from the substrate with the highest productivity was carried out. The results obtained in the parameters of responses in the production of Pleurotus afin ostreatus on an organic residue by the ANOVA method were (p<0.05) and the F-values for the models of factor A (type of substrate), factor B (type of crop) and factor AB (type of substrate and crop) were 6.78, 2.99 and 6.10, respectively. The nutritional composition of the fruiting bodies obtained from this substrate was determined. These fruiting bodies exhibited a considerable water content, which reached 75.44%. On the other hand, a low concentration of carbohydrates was observed, with a value of 15.86%, and a minimal amount of fats, barely 0.13%. It is important to note that there was a particularly notable protein content, which reached 8.09% in relation to the wet weight. Finally, it is concluded that the production values obtained in this research work indicate that the best substrate for the growth of the fungus Pleurotus afín ostreatus is the organic residue S3, whose biological efficiency is among the highest values recorded (37.849%) in the cultivation of this fungus. In addition, in the optimization by means of the factorial design, it was observed that in order to have a greater productive capacity of Pleurotus afín ostreatus, it is necessary to work with a ratio of 40.13C/N and with a type of sampling per day with a mass amount of 77g