The removal of fats, oils and grease (FOG) from food industry wastewater by magnetic coagulation

Wastewater containing fats, oils and grease (FOG) is problematic in several ways: foul odors, blockage of sewer lines, interference with the proper sewage treatment operation and excess amount of FOG that can lead to certain fines for responsible wastewater generator. In this paper, the magnetic coagulation process is used to destabilize the oily wastewater emulsions while assisting with the oil floc formation. The oil/magnetic powder flocs were subsequently deposited and removed with the assistance of magnetic field. Preliminary investigations were devoted to calculations of optimal magnetic field. Preliminary investigations were devoted to calculations of optimal magnetic powder proportions were devoted to calculations of optimal magnetic powder proportions of various sizes and their oil sorption capacity. The results from the jar test confirmed the effectiveness of the magnetic coagulation procedure. It was demonstrated that the magnetic coagulation process with optimum amount of magnetic powder of 12 g/L could remove 94.2% of FOG, 96.9% of total suspended solids (TSS), and 86.7% of chemical oxygen demand (COD) on average.

The removal of fats, oils and grease (FOG) from food industry wastewater by magnetic coagulation

Wastewater containing fats, oils and grease (FOG) is problematic in several ways: foul odors, blockage of sewer lines, interference with the proper sewage treatment operation and excess amount of FOG that can lead to certain fines for responsible wastewater generator. In this paper, the magnetic coagulation process is used to destabilize the oily wastewater emulsions while assisting with the oil floc formation. The oil/magnetic powder flocs were subsequently deposited and removed with the assistance of magnetic field. Preliminary investigations were devoted to calculations of optimal magnetic field. Preliminary investigations were devoted to calculations of optimal magnetic powder proportions were devoted to calculations of optimal magnetic powder proportions of various sizes and their oil sorption capacity. The results from the jar test confirmed the effectiveness of the magnetic coagulation procedure. It was demonstrated that the magnetic coagulation process with optimum amount of magnetic powder of 12 g/L could remove 94.2% of FOG, 96.9% of total suspended solids (TSS), and 86.7% of chemical oxygen demand (COD) on average.

Investigation of Fats, Oils, and Grease Co-digestion With Food Waste in Anaerobic Membrane Bioreactors and the Associated Microbial Community Using MinION Sequencing

Co-digestion of fats, oils, and grease (FOG) with food waste (FW) can improve the energy recovery in anaerobic membrane bioreactors (AnMBRs). Here, we investigated the effect of co-digestion of FW and FOG in AnMBRs at fat mass loading of 0.5, 0.75, and 1.0 kg m–3 day–1 with a constant organic loading rate of 5.0 gCOD L–1 day–1 in both a single-phase (SP) and two-phase (TP) configuration. A separate mono-digestion of FW at an identical organic loading rate was used as the benchmark. During co-digestion, higher daily biogas production, ranging from 4.0 to 12.0%, was observed in the two-phase methane phase (TP-MP) reactor compared to the SP reactor, but the difference was statistically insignificant (p > 0.05) due to the high variability in daily biogas production. However, the co-digestion of FW with FOG at 1.0 kg m–3 day–1 fat loading rate significantly (p < 0.05) improved daily biogas production in both the SP (11.0%) and TP (13.0%) reactors compared to the mono-digestion of FW. Microbial community analyses using cDNA-based MinION sequencing of weekly biomass samples from the AnMBRs revealed the prevalence of Lactobacillus (92.2–95.7% relative activity) and Anaerolineaceae (13.3–57.5% relative activity), which are known as fermenters and fatty acid degraders. Syntrophic fatty acid oxidizers were mostly present in the SP and TP-MP reactors, possibly because of the low pH and short solid retention time (SRT) in the acid phase digesters. A greater abundance of the mcrA gene copies (and methanogens) was observed in the SP and MP reactors compared to the acid-phase (AP) reactors. This study demonstrates that FW and FOG can be effectively co-digested in AnMBRs and is expected to inform full-scale decisions on the optimum fat loading rate.

Hair Care Products Manufacturing Wastewaters: Toxicity and test Organism Sensitivity

Wastewater from two (A and B) small-scale hair care product manufacturers located in the state of Minas Gerais were characterized, with regard to physical, chemical and ecotoxicological parameters. Wastewater characteristics typical for this industrial sector were found in three samples collected at each manufacturing plant, with high levels of both particulate and dissolved organic matter (soluble and total COD), oils and grease and acute toxicity to the microcrustacean Daphnia similis (EC50 < 0.5 %). Strong positive correlations between turbidity, oils and grease and acute toxicity were observed. It is worth mentioning that only one of the manufacturers operates a wastewater treatment plant, while the second discharges untreated wastewater to a local sewer system. Furthermore, neither of the two cities where the enterprises are located has a municipal sewage treatment plant, aggravating environmental impacts of the industrial contributions to sewage discharges in receiving waters. A battery of tests was performed with species from three trophic levels (primary producers and primary and secondary consumers) to select the most sensitive test organisms to the wastewaters evaluated. The microcrustacean Ceriodaphnia dubia is indicated for use in routine monitoring, since it exhibited the highest sensitivities to hair care products wastewaters, for both acute and chronic effects.