Biofilter response to biomass reactivation for VOC treatment

[Abstract] This research has undertaken a comparative study on using a fresh activated sludge or a refrigerated/ reactivated sludge as active biomass source for biofiltration purposes. A sludge sample was initially selected based on the ratio between volatile solid content and total solid content before and after refrigeration at 6 oC for 90 days. The degradation rate of the activated sample for three addition doses of toluene was established before and after refrigeration. The same procedure was also carried out for ethylbenzene and p-xylene after refrigeration/reactivation. Surprisingly, the degradation rate for toluene was higher after refrigeration and the results were very similar for an addition of 2 and 8 µL. Subsequently, one biofilter was inoculated with the activated sample and another with the reactivated sample, and both were fed with toluene ranging from 2.6 to 26.2 g toluene m-3 h-1. Concerning the elimination capacity of both biofilters, no relevant differences were found. It was concluded that the active biomass degrading toluene was not affected by refrigeration, in spite of the fact that the SV/ST ratio decreased after the storage period. The elimination capacity of the other two biofilters (ethylbenzene and p-xylene) was highly influenced by the gas flow rate. 1 INTRODUCTION Environmental regulations for pollution control are frequently enacted before «suitable» (affordable, effective and environmentally friendly) technologies have been fully developed. Amongst biotechnologies, biofiltration is a seemingly simple system whose effectiveness relies on the optimization of several operating parameters and the selection of a suitable packing material and degrading biomas

A comparative study of two processes for indoor vocs treatment: biofiltration vs. hybrid system (biological process+adsorption)

Biofiltration technology and the hybrid system combining biofiltration and adsorption (onto activated carbon) were compared as possible methods to treat indoor air pollution. Toluene and p-xylene at ppb concentration levels (2-45 and 1-33 ppb, respectively) were chosen as characteristic indoor pollutants for this study. An organic material was used as packing material for the biofiltration stage and its acclimation was carried out for 100 days at higher concentrations. Even at low empty bed residence time (EBRTs) and concentrations, toluene removal efficiency reached 100% and p-xylene showed an increasing trend in their removal efficiency over the time. The assessment of by-products and particles generation by the biofilter and the hybrid systems was taken into account. Acetone and acetic acid were identified as by-products of the biofilter. Particle emissions in the range of 0.03 to 10 µm were recorded for both systems which suggest the necessity of using a particle filter at the end of the process chain. Please click Additional Files below to see the full abstract

Multiple Intelligence Informed Resources for Addressing Sustainable Development Goals in Management Engineering

The competence-based model focuses on acquiring skills and abilities, yet each student’s individual circumstances condition the way in which they learn, develop, and implement them. Accordingly, there is a growing interest in defining learning activities that consider the diverse range of intelligences, abilities, and prevailing mindsets in each individual in order to promote inclusive education and sustainable development. This article seeks to design a methodology for the teaching–learning resources associated with the nature of the prevailing intelligence in the competence-based model. Thus, the “competence-intelligence-resource triangle” was proposed for promoting inclusive education in the degree in Management Engineering at the University of the Basque Country (UPV/EHU). A total of 99 teaching–learning resources, 11 competences, and 9 types of intelligence were combined. As far as the multiple intelligence approach is concerned, the 50 students surveyed prioritized logical–mathematical, interpersonal, intrapersonal, linguistic, and spatial intelligences. As a conclusion, the use of teaching–learning resources designed for promoting different types of intelligence in the competence-based model constitutes an adaptive strategy for the students to successfully acquire competences

Bioiragazpena: gasen korronteak tratatzeko aukera garbia

Gasen tratamendurako metodo biologikoak, mikroorganismoek molekula kutsatzaileak degradatzeko duten ahalmenean oinarritzen dira. Metodo hauetariko bat bioiragazpena dugu eta teknologia "garbia", "merkea" eta "eraginkorra" da. Aplikazio ugari ditu, besteak beste, H2S-a bezalako konposatu kirasdun edota toxikoak dituzten gas emarien tratamendua. Kutsatzailearen kontzentrazioa txikia denean eta tratatu behar den gas bolumena handi samarra denean erabiltzen da batez ere. Beraz, hainbat industriak igorritako gasak tratatzeko aplikazio zuzena du

Bioiragazpena: gasen korronteak tratatzeko aukera garbia

Gasen tratamendurako metodo biologikoak, mikroorganismoek molekula kutsatzaileak degradatzeko duten ahalmenean oinarritzen dira. Metodo hauetariko bat bioiragazpena dugu eta teknologia "garbia", "merkea" eta "eraginkorra" da. Aplikazio ugari ditu, besteak beste, H2S-a bezalako konposatu kirasdun edota toxikoak dituzten gas emarien tratamendua. Kutsatzailearen kontzentrazioa txikia denean eta tratatu behar den gas bolumena handi samarra denean erabiltzen da batez ere. Beraz, hainbat industriak igorritako gasak tratatzeko aplikazio zuzena du

Katalizatzaileen prestakuntza industri prozesuetarako

Prozesu katalitikoak gero eta gehiago erabiltzen ari dira industria eskalan. Prozesu hauetan erabiltzen diren katalizatzaileak arreta handiz prestatu behar dira, solidoak ezaugarri fisiko-kimiko (aktibotasun, hautakortasun ete egonkortasun) onak eduki ditzan, eta erreakzio katalitikoa egoki gerta dadin. Artikulu honetan industria eskalan masa-katalizatzaileak eta katalizatzaile inpregnatuak prestatzeko normalean erabiltzen diren metodoak deskribatzen dira eta prestakuntza-etapa bakoitza zertan datzan aztertzen da

Katalizatzaileen prestakuntza industri prozesuetarako

Prozesu katalitikoak gero eta gehiago erabiltzen ari dira industria eskalan. Prozesu hauetan erabiltzen diren katalizatzaileak arreta handiz prestatu behar dira, solidoak ezaugarri fisiko-kimiko (aktibotasun, hautakortasun ete egonkortasun) onak eduki ditzan, eta erreakzio katalitikoa egoki gerta dadin. Artikulu honetan industria eskalan masa-katalizatzaileak eta katalizatzaile inpregnatuak prestatzeko normalean erabiltzen diren metodoak deskribatzen dira eta prestakuntza-etapa bakoitza zertan datzan aztertzen da

Ohizko energiak vs. energia berriztagarriak

Fosil-erregaien erreserbak gero eta urriagoak dira eta munduko leku mugatuetan baino ez daude. Gainera, erregai mota hau erabiltzen duten prozesuak oso kutsatzaileak izan ohi dira. Arazo hauek dira medio, gizartean energia aurrezteko konpromisoa gero eta finkatuago dago (batez ere herrialde industrializatuetan) eta gero eta energia lor tzeko prozesu eraginkorragoak eta garbiagoak diseina tzen ari dira. Hala ere, oraindaino energia garbia eta ugaria lor tzeko lehendabiziko pausuak baino ez dira eman. Lan honetan ohizko energiak eta energia berriztagarriak deskribatzen dira eta bai eta energia mota bakoi tzaren abantailak eta desabantailak

Ohizko energiak vs. energia berriztagarriak

Fosil-erregaien erreserbak gero eta urriagoak dira eta munduko leku mugatuetan baino ez daude. Gainera, erregai mota hau erabiltzen duten prozesuak oso kutsatzaileak izan ohi dira. Arazo hauek dira medio, gizartean energia aurrezteko konpromisoa gero eta finkatuago dago (batez ere herrialde industrializatuetan) eta gero eta energia lor tzeko prozesu eraginkorragoak eta garbiagoak diseina tzen ari dira. Hala ere, oraindaino energia garbia eta ugaria lor tzeko lehendabiziko pausuak baino ez dira eman. Lan honetan ohizko energiak eta energia berriztagarriak deskribatzen dira eta bai eta energia mota bakoi tzaren abantailak eta desabantailak

Sustainable mold biomachining for the manufacturing of microfluidic devices

Biomachining has been investigated as a sustainable and effective alternative to conventional prototyping techniques for molding polymeric materials for their subsequent use as microfluidic devices. A novel and simple process based on the combination of a Pressure Sensitive Adhesive mask and a varnish has been proposed for preparing metal workpieces as an alternative to photolithography, with the latter being the most widely used technique for protecting workpieces. As far as the bioprocess is concerned, it has been applied in successive mold-etching and oxidant bio-regeneration stages. Metal solubilization has proven to be repeatable in several consecutive mold-etching stages when using the regenerated oxidant solution. As a result, the lifespan of the biomachining medium has been prolonged, contributing to process sustainability. An equation with two restrictions has been proposed to predict the time required to obtain a mold with a fixed height, as metal solubilization evolves differently between the first and subsequent hours. Finally, the bio-engraved copper pieces have acted as effective molds in the fabrication of self-powered polydimethylsiloxane microfluidic devices. This new biomachining application is therefore an effective and ecofriendly process for producing microfluidic devices.This work was supported by the State Agency for Research (AEI) of the Spanish Government-European Regional Development Fund (FEDER-ERDF, EU) [grant number: CTM2016-77212-P], Spain’s Ministry of Science and Education [grant number: PID2020-120313 GB-I00/AIE/10.13039/501100011033], and the Basque Government’s Department of Education for the consolidation of research groups [grant number: IT1633-22]. Professor L. N. López de la Calle is acknowledged for his assistance with the copper samples