Removal of fluor and nitric compounds from waste water

Research performed in the area of decontamination and fluor removal from waste water using AVS shows (table 5) that these devices are more efficient compared to the existing equipment.

Fluor removal and transformation of phosphates into water-insoluble compounds occurs in one stage. The content of fluor in purified waste water in optimal conditions (pH = 10-11) up to 1.5 mg/dm³, no phosphates. Duration of processing in the vortex layer: 1-3 seconds. A reasonable choice of reagent is lime with 5-10% excess of CaO from the theoretically calculated amount. Using AVS in the process of fluor removal reduces reagent consumption, electric power consumption, equipment footprint and improves the quality of purification.

Mean processing rate of the AVS is approximately 30000 m3/hour per 1m³ of active zone volume, which corresponds to AVS -100 capacity up to15 m³/hour, and AVS-150 capacity up to 40 m³/hour.

Table 5

Influence of AVS processing on waste water purification

Initial parameters				Waste water parameters after AVS processing
Waste water			Lime milk
pH	F, mg/dm 3	P2O5, mg/dm3	CaO, %	pH	F, mg/dm 3	P2O5, mg/dm 3
3,65	350	2100	105	7,6	10	32
3,65	700	2250	105	8,2	7,5	8
5,9	1100	3200	105	9,2	5	0
3,0	1500	6500	105	11,5	1,2	0
3,0	1500	5100	110	11,6	1,15	0
3,95	750	5000	110	9,3	4,5	0
3,95	750	5050	110	8,6	7,1	0
3,95	750	5050	110	10,0	1,4	0

The use of AVS to remove aromatic nitric compounds from waste water by reducing them to the corresponding amines is quite promising as well. The recommended ferromagnetic elements for this process are made of carbon steel, 1 – 1.4 mm in diameter, with 1/d ratio of 12 to 16.