Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

Editors' Foreword

This article presents the results obtained from the valuation of solid waste generated in the packaging lines in an agrochemicalcompany. The guidelines established by Dr. Kunitoshi Sakurai were used to separate, classify and characterize solid waste into two groups:recyclable and non-recyclable, in the month of July 2016. The results obtained determined that 81% of solid waste is recyclable and 9% arenot recyclable. The classification and characterization of non-recoverable residues showed that the group called "rags" has the highest heatcapacity (1.04e14 kJ / kg). Additionally, it was demonstrated through the valuation that the recyclable solid waste from the factory wouldprovide an annual income of $ 16,793.

The treated waters from the effluent of a facultative lagoon used to the secondary treatment of domestic wastewaters from the Aurora II colony in the wastewater treatment plant Arturo Pazos Sosa, can be reused in a tertiary treatment by using common carp (Cyprinus carpio) and golden carp (Carassius auratus) fingerlings. In this articule, the results of the research are presented using a small-scale ponds system with common carp and golden carp fingerlings, configured in parallel where the flow coming from the effluent facultative lagoon of the secondary treatment was distributed equitably to each of the ponds, with a hydraulic retention time (HRT) design of approximately 76 minutes. Each pond contained 25 fingerlings per type, this in order to evaluate the removal efficiency of selected water quality parameters. Eight water quality sampling were determined at the input and at the output of tertiary treatment for 4 months. The simple or punctual samples were taken every fifteen days, for a total of thirty-two samples. To evaluate the removal efficiency of the tertiary treatment were selected three main parameters, being the biochemical oxygen demand (DBO5), total phosphorus and fecal coliforms. The removal efficiency of the common carp fingerlings was of 8.86% to DBO5, 7.13% to total phosphorus and 7.46% to fecal coliforms. The removal efficiency of the golden carp fingerlings was of 7.69% to DBO5, 7.97% to total phosphorus and 8.47% to fecal coliforms. The efficiency in the removal of the parameters evaluated by the presence of the fingerlings were less than 10.0%, for this reason the use of fish as tertiary treatment is not recommended, however, they can be used as bioindicators capable of demonstrate that the water quality in the effluents of the facultative lagoon is good.

This article presents an analysis of the volumes, technical and environmental aspects for the proper management of solid waste generated in the municipality of Salcajá, department of Quetzaltenango, based on the physical and chemical characteristics, and the capacities of the municipality. The current situation was diagnosed, in terms of the waste characteristics, collection and transport service, cleaning of public areas, treatment and final disposal. An average production volume of 11,214 kg / day of solid waste was determined, equivalent to a per capita production of 0.54 kilograms / habitant / day, of which 52.58% is organic compostable. 4.55% paper and cardboard, 9.48% sanitary waste, 4.84% plastic, 8.62% food waste, 4.15% textiles, 5.86% metals, 1.59% duroport, 3.42% glass, 2.28% aluminum and 2.64% electronic, the pH of waste generated solids is 5.74, the humidity percentage is 82.68%, the percentage of ash is 16.76%. Based on these results, a proposal was made for the final disposal of waste, and the capacity of the municipality to develop this action plan in a way that is technically sustainable, as well as the factors that allow the environmental sustainability of said proposal, were analyzed through the implementation of a modified Leopold matrix.

This article presents the main results to determine if it is technically feasible or not the use of residual cooking oil for the formulation of a bar soap, as an alternative to reduce or minimize the impacts to the environment due to its inadequate final disposal in soils and water bodies. The bar soap was formulated using the next ingredients: waste cooking oil from a restaurant, sodium hydroxide, distilled water and fragrance. The technical feasibility in making bar soap was determined based on the basis of the similarity of the physicochemical properties of pH, electrical conductivity, surface tension, density and COD of soapy water respect to the conventional bar soap, evaluated at through the Student's t-distribution. The range obtained of the results of pH are from 7,05 to 9,13 units, the electrical conductivity from 32,5 to 182,5 μS/cm, density from 0,99 to 1,04 g/mL, the surface tension from 27,88 to 37,39 dyne/cm and for the COD from 300 to 2 800 mg/L. The obtained graphs present similar trends, whose data were corroborated by Student's t-distribution. The formulation and elaboration of bar soap is technically feasible, since there is no significant difference between the evaluated physicochemical properties of soapy water, being an option for environmental sanitation. The final product was a yellow soap, with a pleasant characteristic door, which when applied to the skin duringhand washing, leaves the skin clean, soft and moisturized, without dryness, which contributes to the health benefit of people.

This article shows the results of applying Moringa Oleifera as a coagulant in turbidity removal processes for the purification of raw water. Thisgenerates sludge to which it is necessary to give them some type of treatment prior to their final disposal, therefore, it is necessary to determinetheir biodegradability. To determine the biodegradability of the sludge, a methodology was proposed in which sample water was used fromthe high plateau and conducted through the Xayá Pixcayá aqueduct to Guatemala City, dividing this sample water into five parts and thendiluting it to five turbidity ranges. For each of the turbidity ranges, biochemical oxygen demand (BOD5) and chemical oxygen demand (COD5)were determined under optimal dosing conditions. The biodegradability index was obtained as a result of dividing the COD with the BOD5,which resulted in the average biodegradability index of 2.23 with a confidence interval of 1.83 to 2.62, which indicates that these sludges arevery biodegradable, using the criterion of Hernández & Galán (2004). When considering both the biodegradability index obtained and itsconfidence interval, it is determined that these sludges can be subjected to biological treatment, in order to reduce their volume and healthrisk.

This article presents the relationship between the bacteriological quality of water and the oxide-reduction potential (ORP) in a water treatment plant. For this, a monitoring it was carry out determining the values of ORP and fecal and total coliforms in the fast filtration unit and in the reservoir of drinking water with disinfected water. According to the results obtained, the presence of fecal and total coliforms occurred with average values of oxide-reduction potential (ORP) of 250 mV, and the absence of these was presented with an average ORP of 760 mV. The research work showed that there is a relation of presence absence of fecal and total coliforms with respect to the potential of oxide reduction, so it is possible to use this parameter to determine the presence or absence of coliforms in water in a water treatment plant. According to the statistical analysis performed for the data obtained from coliforms in the filtration unit, it was obtained that there is no direct correlation between the ORP and fecal and total coliforms, given that the Pearson coefficients found were -0.203, -0.388 with a significance of 0.549 and 0.239 respectively, which shows that there is no statistically significant relationship between these variables. For ORP values below 300 mV, there is no linear behavior that allows to establish the ratio of fecal and total coliforms with the oxide-reduction potential.

The study of kinetic coefficients of trickling filters in stages, filtration medium of volcanic stone, in the treatment of wastewater of Wastewater Treatment Plant of USAC, which responds to a good performance in the efficiency of removal of organic matter; but it is important to the study of the kinetic coefficients to determine design parameters for this type of units. The characterization of residual water from domestic, as the biochemical oxygen demand (BOD5) and the chemical oxygen demand (COD) are the main parameters to be evaluated. This study uses the equation of Eckenfelder, whose model considered the kinetic coefficients of: (n) and (K); and according to the methodology it is solved using COD and BOD5 data in the laboratory by graphical method. According to the results of the filters trickling manages to remove the 89.70% of organic matter, considering that the filter medium is stone maze of sizes 2 1/2 ", 3"and 3 1⁄2"respectively in each filter. The characteristic of organic and hydraulic load are low load, and the average temperature of 25°C. The kinesthetic certain coefficients are: n = 0.673; K = 0.0294 m0.673*day-0.673.  

This article presents an assessment of vulnerability and risk of the underlying aquifer in the municipality of San Pedro La Laguna, Sololá. The evaluation was carried out applying the GOD method (Groundwater occurrence-overall aquifer class-Depth) (Foster, 1987), to determine the vulnerability, and to determine the risk and protection priority, the vulnerability results were combined with the pollutant load evaluation method. POSH (Pollutant Origin Surcharge Hydraulically) (Foster and Hirata, 1988). With the application of the methodology in a small region, risk zones were established that were compared with the concentrations of nitrates detected in the analytical campaigns carried out in which concentrations of nitrates in a range of 7.92 to 118.80 mg/L in rainy season and 13.00 to 506.0 mg/L in dry season. For a simple utility, vulnerability, risk and protection maps were developed that can be useful tools for the planning of the territorial ordering of the area, the management and control of water resources.

This article presents the issue of the production of domestic sewage sludge, in the stabilization lagoons of the pilot plant Ing. Arturo Pasos Sosa, of the ERIS Sanitary Engineering Regional School of the University of San Carlos of Guatemala, in the system in series of two lagoons, being the first facultative and the second of maturation, in order to determine the production of sludge per capita. The estimation of the total volume of sedimented muds and their spatial distribution was determined by performing bathymetry, which was developed with a grid with squares of one meter by one meter, on which the measurement of heights was made. For the facultative lagoon, 736 measurements of mud height were made, and 768 height measurements were made in the maturation lagoon. The zones with the highest accumulation of sediment sludge were determined by analyzing the behavior of the sedimentation in relation to the total length of the lagoon. A sludge production value of 0.075 m3 / inhabitant / year was obtained. The operation time for the analysis of the stabilization ponds, on the date of the study was 12 years (2,004 - 2,016) from its construction and operation.