Abstract
Laboratories consume great amounts of hazardous chemicals substances and consequently generate wastewater containing them, for example formaldehyde. This substance is widely utilized to preserve biological samples generating many liters of this residue every year. The present work proposes the use of the photo-Fenton process to treat formaldehyde wastewater using sunlight irradiation. Some aspects were investigated such as the iron source, sample and hydrogen peroxide concentration and also the use of stirred systems. The use of ferrioxalate (0.5 mmol L-1) improved the efficiency of the process in relation to the use of iron nitrate, while at least 1.0 mol L-1 H2O2 is necessary to treat the sample of the 500 mg C L-1. Under these conditions, every formaldehyde detectable was degradeted and 89% of the dissolved organic carbon was removed in two hours of exposure to sunlight. These results are satisfaction considerate for São Paulo State Environmental Agency.
Highlights
A large number of biological laboratories use solutions of formaldehyde to preserve anatomic pieces, generating many liters of formaldehyde waste every year
Every formaldehyde detectable was degradeted and 89% of the dissolved organic carbon was removed in two hours of exposure to sunlight
The photodegradation process was monitored by measuring the Total Organic Carbon (TOC) concentration using an organic carbon analyzer (TOC 5000A Shimadzu)
Summary
A large number of biological laboratories use solutions of formaldehyde to preserve anatomic pieces, generating many liters of formaldehyde waste every year. The concentration of formaldehyde is just 3.7% w/w, discharging formaldehyde without treatment can cause serious damage from aquatic environment, due to its carcinogenicity [4] and there is no safe limit to exposition for this class (carcinogenic). The adequate treatment of wastes generated by industrial, agricultural or domestic activities is regulated by environmental agencies throughout the world, [5,6] which the levels of specific parameters are limited and checked in the discharged wastes. This is necessary due to large volumes of toxic generated wastes and to the impacts that this cause. Iinntteerrffeerreenngccreeessa,,taaessrwwwaahssetthhnee, cacaalosseendgdeewssccirrtiihbbeetddheaabbaooqvvueee.. ous solution of formaldehyde, the residue presents a high concentration of organic compound and interferences, as was the case described above
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
