In this research, the presence of microplastics was detected through a differential scanning calorimetry (DSC) analysis of three wastewater treatment plants. One of these plants applied only a preliminary treatment stage while the others applied up to a secondary treatment stage to evaluate their effectiveness. The results showed the presence of polyethylene (PE), polystyrene (PS), polypropylene (PP) and polyethylene terephthalate (PET), which were classified as fragments, fibers or granules. During the evaluation of the plants, it was determined that the preliminary treatment did not remove more than 58% of the microplastics, while the plants applying up to a secondary treatment with activated sludge achieved microplastic removal effectiveness between 90% and 96.9%.

The addition of polymers in construction is a new tendency and an important step toward the production of structures with better functional properties. This work investigates the addition of polyurea (PU) as a polymeric material in mortars. Polymer mortars were manufactured with the addition of polyurea retained in different sieves (T50 and T100) and different concentrations (2% and 5%). The characterization of the, polyurea (PU)control mortar (PU0%) and manufactured polyurea mortars (PU2%T50, PU5%T50, PU2%T100, and PU5%T100) was conducted by means of morphological analysis, SEM, XRF, TGA, and a compressive strength test of hydraulic mortars. The results show that mortars with polyurea retained in sieve 100 with a particle size of 150 μm exhibit better thermal behavior and a greater resistance to compression with a concentration of 5% polyurea with respect to the other samples. The present work reveals that polyurea retained in sieve 100 can be considered as a polymeric additive for mortars, indicating that it could be a candidate for applications such as construction.

<p>This paper presents the first systematic atmospheric corrosion assessment in Bogota. Main facts about the study are related with special characteristics of the City, such as population (more than eight million inhabitants), and altitude (2600 m over the sea level). Relative humidity, temperature, and SO2 concentration were measured. Simultaneously, corrosion rate of AIS/SAE 1006 plain steel was measured along one year. Results show that atmospheric corrosion is between C₂ – C₃ levels, according to the ISO 9223 standard. Nevertheless, estimations from meteorological parameters produce lower corrosivities and, taking into account SO2 concentrations, corrosivities in places with higher relative humidity, are higher than corrosivities measured on steel coupons. In general, the main pollution problem is particulate matter, but higher corrosion rates were directly associated with SO2 levels. Gaps between found results and international estimation methodologies are evident. Some explanations about that, are proposed.<strong></strong></p>

Limited studies have been carried out in emerging nations on the correlation among the environmental pollution, economic factors, and architectural heritage. For this reason, this research presents an assessment of environmental parameter values on materials deterioration used in architectural heritage in Cartagena de Indias; furthermore, it depicts the effect of heritage degradation on socioeconomic aspects of people whose livelihood depends on trade, tourism, and service activities. Dose-response functions were used for estimating of deterioration of carbon steel, copper, and zinc caused by relative humidity (RH), temperature (T), sulphur dioxide deposition (DSO2), and chloride deposition (DCl−). In addition, socioeconomic impact on architectural heritage was studied using a Socioeconomic Impact Survey (SEIS), with the sample of 174 individuals who work in areas of great architectural value in the city. The results show a corrosion rate (Vcorr) in the range of 80 < Vcorr < 200, 2.8 < Vcorr < 5.6 and 4.2 < Vcorr < 8.4 μm/year for carbon steel, copper, and zinc, respectively, due to the high level of pollutants. The high deterioration jointly with the lack of citizen culture affect the architectural heritage monuments causing a negative impact in several economic aspects. The establishment of public programs is essential for the conservation of the heritage monuments of the city.

The corrosion behavior of electrolytic copper (&gt;99.5% purity [UNS C11000]), carbon steel (AISI/SAE 1016 [(UNS G10160]), and Type 304 (UNS S30400) stainless steel in neutral tap water was examined by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) using a rotating cylinder electrode (RCE). The instantaneous corrosion rates determined from polarization curves were 0.2, 15, and 140 μm y−1 for stainless steel, copper, and carbon steel, respectively. These values were found to be consistent with those reported by the weight-loss method, thereby allowing RCE to be used for the rapid estimation of corrosion rates. Results showed that the corrosion behavior is not directly dependent on hydrodynamic conditions even under turbulent flow. The corrosion resistance does not seem to be related to the intrinsic reactivity of each metal but rather to the oxide film structure on the metal surface. The low resistance of carbon steel, hence, is caused by the formation of a porous layer that does not prevent metal dissolution. In the case of copper, the corrosion process is controlled by the formation of a stable oxide film. Finally, stainless steel showed a very low corrosion rate because of a passive protective layer on its surface.