The Beginnings of Unsustainability: Urban Problems and Institutions in Temuco, 1955-1970

This paper explores the urban problems that took place in Temuco (Chile) between 1955 and 1970 and how the institutions tried to solve them. To reconstruct the history of the local urban development primary sources, press archives, regional management records and minutes written by the municipal councils were used. The results indicate that, at that time, the city experienced a strong population growth derived from rural-urban migration generated by the ISI model, which led to a number of drawbacks such as paving, traffic congestion, and lack of basic services and housing. We conclude that centralized institutional efforts offered slow solutions that did not fit completely the local conditions and intensified the effects of the problems as well as helped to destabilize the balance between the spheres of sustainability

Nitrification in the presence of sulfide and organic matter in a sequencing moving bed biofilm reactor (SMBBR) with zeolite as biomass carrier

BACKGROUND: The biological nitrification process is inhibited in the presence of sulfide and organic matter (OM). The use of immobilized biomass on inert carriers may help to decrease this inhibition. Thus, the main goal of the present work was to develop a sequencing moving bed biofilm reactor (SMBBR) using zeolite as biomass carrier and to determine its performance in presence of sulfide and OM. RESULTS: The use of zeolite as biomass carrier improves both the total ammonia nitrogen (TAN) oxidation and nitrate accumulation, allowing the system to be able to treat higher nitrogen loading rates. The SMBBR with zeolite in presence of sulfide and OM performed nitrification better than a sequencing batch reactor (SBR), by keeping the TAN and chemical oxygen demand (COD) removal efficiency at >90% for both inhibitory conditions. The SMBBR also is able to degrade COD by ≤98%. Finally, biomass with zeolite settled faster than biomass without zeolite, improving the sludge volume index (SVI) by 53.8%. CONCLUSIONS: It was possible to develop a SMBBR system using zeolite as biomass carrier. The SMBBR could maintain a nitrifying system under inhibitory conditions, allowing efficiencies of TAN and COD removal as high as 90%. © 2019 Society of Chemical Industry

Elemental sulfur-based autotrophic denitrification in stoichiometric S0/N ratio: Calibration and validation of a kinetic model

The inclusion of S0 hydrolysis in a kinetic model of autotrophic denitrification has been recently proposed; however the model has not been calibrated or validated yet. Thus, a new methodology was developed and applied to calibrate and validate this kinetic model for the first time. An inoculum adapted from a poultry wastewater treatment plant at stoichiometric S0/NO3− ratio was used. The model was calibrated with batch data (initial nitrate concentrations of 50 and 6.25 mg NO3−-N/L) at an S0/N ratio = 2.29 mg S/mg N and validated with seven different batch data. The sensitivity analysis showed that the most sensitive parameters are related to S0 hydrolysis. The kinetic model was successfully calibrated with the new methodology and validated, with Theil inequality coefficient values lower than 0.21. Thus, the proposed model and methodology were proved to be well suited for the simulation of elemental sulfur-based autotrophic denitrification in batch systems

Mapuche-Pewenche knowledge transmitted by teachers and parents: perception of schoolchildren in rural schools of the Araucania region (Chile)

In Chile, two public policies focusing on teaching-learning among primary school children have been implemented to contribute to the development of the language and culture of indigenous peoples and to the formation of intercultural citizens: 1) the Bilingual Intercultural Education Programme (PEIB); and 2) the Indigenous Language Sector (SLI). The present study assessed perception of Mapuche knowledge among schoolchildren in schools located in the Mapuche-Pewenche territory of the Araucania Region. The methodology used for data collection was analytical-observational with a Likert-type questionnaire, applied to children in schools registered and not registered for these policies. The statements had two dimensions: the roles assumed in the transmission of knowledge by these public policies and by families respectively. The results showed that the children belonging to schools registered for these policies, expressed disagreement with most of the statements concerning the transmission of that knowledge; while the children in schools not registered for the policies considered that there was indeed transmission of knowledge. The latter result was related to the loss of valuation of this knowledge by these children. In both cases, the children recognised that knowledge is transmitted fundamentally within the family