Looking forward to comments and suggestions to the following:
It is quite common to use chlorine-based (sodium hypochlorite) Open Plant Cleaners (OPC) foam cleaners in slaughter houses. Using such cleaners can however lead to high levels of AOX in waste waters.
To adjust the final pH of the waste water carbon dioxide (CO2) is used instead of using standard acids, e.g. sulfuric or hydrochloric acid.
The CO2 is injected via a nozzle. The question is whether there is such a significant drop in the pH value at this point and whether this promotes the formation of AOX due to the higher reactivity.
Are there any extra ways we can reduce the AOX levels, considering high AOX levels cannot not be avoided when using hypochlorite-based cleaners?
Looking to response!
Dear Anthony,
this is a really good use of CO2. but could you please let me know how do you adding CO2? pure CO2?
thanks,
Amila.
AOX is a measure of the organic halogen load at a sampling site such as soil from a land fill, water, or sewage waste. In this procedure chlorine, bromine, and iodine are measured as equivalent halogens, but does not measure fluorine levels in the sample. It is determined by adsorption onto granular activated carbon (GAC), washing the adsorbed sample and GAC to remove inorganic halides, combustion of the sample and GAC to form the hydrogen halides’ Organic halides are organic compounds containing a halogen atom bonded to a carbon (C) atom. Fluorine (F), chlorine (Cl), bromine (Br), and iodine (I) are all types of halogen atoms. A compound that contains an carbon atom bonded to a fluorine atom (C–F) is called an organofluoride.
In water treatment plants, organic halides are adsorbed using GAC or PAC in agitated tanks. The loaded carbon is separated using a membrane made out of materials like polypropylene or cellulose nitrate. Measuring the AOX levels into and out of the treatment zone shows a drop in organic halide concentrations. Some processes use a two-step GAC filtration to remove AOX precursors, and thus reduce the amount of AOX in treated waters. A two step filtration process consists of two GAC filters in series. The first filter is loaded with exhausted GAC, while the second filter is loaded with fresh GAC. This set up is preferred for its increased efficiency and higher throughput capacity. The GAC is replaced cyclically and the extracted organic halide-carbon mixture is then sent for subsequent biological or chemical treatment such as ozonation to regenerate the GAC. Often, these chemical treatments, while effective, pose economical challenges to the treatment plants. https://en.m.wikipedia.org/wiki/Adsorbable_organic_halides
A more economically attractive option for treatment of the organic halides is through utilization of biological agents. Recently, bacteria (Ancylobacter aquaticus), fungi (Phanerochaete chrysosporium and Coiriolus versicolor), or synthetic enzymes have been used in the degradation of chlorinated organic compounds. The microorganisms degrade halocompounds using either aerobic or anaerobic processes. The mechanisms of degradation include utilization of the compound as carbon source for energy, cometabolite, or as an electron acceptor. Note that enzymatic or microbial action could be regulated through feedback inhibition-the final product in the series inhibits a reaction in the process. https://en.m.wikipedia.org/wiki/Adsorbable_organic_halides
I recently read some article in this field
I hope they are helpful
Article Relationship between centrifugation and drying of sludge and...
Article Biodegradability Studies on Pulp and Paper Mill Wastewater: A Review
Article BIOREMEDIATION OF INDUSTRIAL EFFLUENTS OF ASANSOL DURGAPUR I...
Regards
Hello Anthony,
Kindly read this paper.
https://core.ac.uk/download/pdf/147253364.pdf