Basic situation of pesticide wastewater
This case study is to share our method, testing processes, and results toward pesticide wastewater solely from pesticide and herbicide manufacturing plants.
Challenges: pesticide wastewater source, pollutants
Major water samples of this pesticide wastewater are originated from pesticide and herbicide manufacturer, this manufacturer mainly manufacture and supply Acetamiprid, imidacloprid, malathion, nicosulfuron, imazethapyr, clethodim and etc.
And the water source are mixed waste streams collected from different processes and manufacturing department of this manufacturer, therefore the main pollutants, substances and content are pesticide and herbicide.
Volume of this pesticide wastewater
There were three types of pesticide wastewater, and we managed to sorting these pesticide waste streams into accordingly, 50-100 metric ton per day
Some 9000 tons of sodium salt wastewater is with a salt content of 14.18%, mainly sodium chloride, and a 3000 tons of wastewater with ammonium salt, with a sale content of 34.07%, and mainly ammonium sulfate and ammonium chloride, and 6000 tons of wastewater with a comparatively lower salt content at 7.6%, mainly with sodium chloride.
Characteristics of pesticide wastewater
Check the major characteristics of this pesticide wastewater we listed below:
Initial COD value of pesticide wastewater:
Ammonium salt wastewater, 120800 mg/l
Sodium salt wastewater, 107200 mg/l
Low-salt wastewater, 206400 mg/l
Initial TOC value of pesticide wastewater:
not recorded back the date of testing.
Initial Ammonia value:
Ammonium salt wastewater, 21200 mg/l
Sodium salt wastewater, 378 mg/l
Low-salt wastewater, 56.2 mg/l
pH value:
Ammonium salt wastewater, 8.56
Sodium salt wastewater, 5.87
Low-salt wastewater, 7.42
Chloride ion concentration level:
Ammonium salt wastewater, 32489.93
Sodium salt wastewater, 69978.3
Low-salt wastewater, 21243.41
The pesticide manufacturer reaching out to Evoaeo team to conduct site inspection, alternative treatment processes and technology proposals, and erection of electrochemical oxidation wastewater treatment systems to tackle the challenges.
Site conditions
These water tanks are 18,000 cubic meters in existence, and the production plant has closed down. No new water will be produced. It takes about a year to complete the processing, so the future processing capacity of the system is 50 tons/day.
Electrochemical oxidation wastewater treatment system covering electrochemical oxidation wastewater treatment electrolyzers, control panel integrated PLC, circuit control, and pumping system, septic tanks, and supporting accessories, ready to intallation for on-site treatment of pesticide wastewater with high amount of sodium salt, source, Evoaeo pesticide wastewater degradation project introduction and data report from this specific case study, copyrights reserved.
Experimental approaching for on-site advanced electrochemical oxidation treatment of pesticide wastewater
This experiment was aimed to conduct on-site electrochemical oxidation treatment of pesticide wastewater based on the mechanisms and basic principle of electrochemical oxidation wastewater treatment processes and technologies by utilizing BDD electrode as the core catalyst material, and an enhanced electrochemical reactor to reduce recalcitrant organic pollutants gradually, and then eventually mineralize those organic compounds that are refractory to conventional treatment processes and technologies, and given the high salinity of this type of waste stream, refractory to conventional biological wastewater treatment methods, and degrade those organic compounds into inorganic compounds, carbon dioxide (CO2) and H2o.
With boron doped diamond BDD anodes, and coated titanium cathodes, and well engineed electrochemical reactor, once electric current applied, mineralization of organic compounds sorted into to two basic methods,
That is direct oxidation, direct oxidation involves direct electron transfer among the boron doped diamond BDD anodes and organic compounds, which means those organic compounds were converted to intermediates, followed by further oxidation within the solution.
The other process is indirect oxidation which including electrogeneration of oxidizing agents, mainly hydroxyl radicals, Ozone, hydrogen peroxide, and active secondary oxidants, given the unmatched oxidation power of these oxidizing agents, recalcitrant organic compounds were destroyed and decomposed into intermediates, bulk generation of those oxidizing agents ensured constant decomposition and mineralization of these organic compounds.
4. Electrodes
4.1 Anode:
Two BDD electrodes with a single crystal silicon substrate, with an area of 200cm2.
4.2 Cathode:
Three titanium sheets.
5. Experimental operation
Take 900 mL of water samples and place them in a beaker; put in the BDD electrode module (the actual area of the anode is 150cm2), heat the water sample to a constant temperature of 7oC; connect the power supply, adjust the current intensity to 4.5A, and begin to degrade. During the degradation process, the water sample was stirred with a magnetic stirrer to make it uniform. Samples are taken at regular intervals, the current and voltage values are recorded, and the temperature and pH value is measured.
6. Experimental phenomenon
Before degradation, the water sample was brown-black; during the degradation process, the color gradually faded; a small amount of brown precipitation was produced.
