The soils of rural roads in Guayas province are characterized by being clayey and expansive, causing problems for vehicular and pedestrian traffic. This research analyzes the use of gravel as granular material in its natural state and then combined with another aggregate of the same category for soil stabilization. A qualitative experimental procedure was conducted to obtain laboratory results from natural and combined samples.
After testing, soil properties were compared in both states, determining that a 50% dosage of each material improved the soil’s physical-mechanical characteristics: reduced plasticity index, increased maximum dry density, and significantly improved bearing capacity, meeting MTOP guidelines for subgrade improvement with selected material.
This study evaluates the degradation of surfactants in wastewater generated by the electroplating industry using an integrated treatment train comprising physicochemical, biological, and electrochemical processes. The research addresses compliance with maximum permissible discharge limits established by the Unified Text of Secondary Environmental Legislation (TULSMA) and contributes to sustainable water resource management in the province of Guayas. The primary objective was to determine a technically efficient, scalable, and environmentally sound treatment configuration capable of reducing surfactants and associated contaminants derived from electroplating operations.
Comprehensive wastewater characterization, treatability tests, and process performance evaluations were conducted at an average influent flow rate of 20 m3 per day. Primary treatment via dissolved air flotation achieved effective removal of oils and greases and ten percent reduction in chemical oxygen demand and biochemical oxygen demand. Secondary treatment consisted of an activated biological system enriched with enzymes, urea, and phosphates, which enhanced microbial activity, promoted biodegradation of organic matter, facilitated surfactant removal, and induced precipitation of dissolved heavy metals. Tertiary treatment involved electrochemical oxidation using electrolytic cells, enabling surfactant hydrolysis and further reduction of recalcitrant compounds.
The integrated treatment system achieved significant reductions in organic load, surfactant concentration, and metal content, producing an effluent that met all applicable regulatory discharge standards. The results demonstrate that the combined biological and electrochemical approach represents an effective, robust, and sustainable alternative for the treatment of electroplating wastewater. Furthermore, the proposed treatment scheme exhibits operational flexibility and potential applicability to other industrial effluents characterized by complex pollutant matrices and stringent regulatory requirements.