Model-Driven Strategies for Sulfide Control in a Regional Wastewater System Receiving Tannery Effluents in Portugal

Abstract

Ageing infrastructure are a concern for many wastewater utilities. This is accentuated with the presence of hydrogen sulfide within the sewer headspace, known to induce concrete corrosion, toxicity and odours. Some industrial effluents contain significant sulfide concentrations, however most field studies in the literature refer to domestic networks, or lab/pilot scale sulfide abatement strategies for varied effluents. Hence, the objectives of this work are: (1) To obtain data regarding the evolution of sulfides in a full-scale industrial sewer system in Portugal, receiving wastewater from a number of tanneries; (2) model their fate within the system and (3) experimentally evaluate sulfide precipitation with iron salts. Field work evidenced heavily sulfide loaded effluents, exceeding by far literature values for sewer systems. Modelling was carried out based on the AeroSept+ model, specifically calibrated to this type of effluent. Results showed the model was capable of reproducing the overall levels of sulfide in wastewater and H2S in the sewer headspace, while allowing insights into industrial discharges, originating a set of proposed interventions for sulfide abatement. This may be carried out by iron salts addition, in a ratio of 2.75:1, at existing monitoring stations. This approach was fundamental for an affordable performance assessment, under considerable uncertainty.

External Thermal Insulation Composite Systems (ETICS) from Industry and Academia Perspective

“…The study of the global performance of systems with the ICB and EPS by Malanho et al has shown that ETICS with ICB that reduces the environmental footprint is characterized by satisfactory global performance, similar to ETICS with EPS global performance [93]. Matos et al presented an overview of the LCA study of ETICS with ICB developed to obtain EPD according to EN 15804 and ISO 14025 [94]. Recently, Silvestre et al considered ETICS with EPS and ICB in the energetic renovation of the building envelope during a fifty-year study period.…”