Afm pressure filter compared against a moving bed sand filter in sewage effluent

The following graphs relate to a direct comparison between a moving bed sand filter with a bed depth of approximately 2.5 metres and a simple pressure filter containing a 30cm (1/10th of the sand) bed depth. The water in question was final effluent discharge from a sewage works using percolating filters.

There was not a great deal of difference between the results of the sand filters and AFM filters. However when the size, flowrates and bed depth are taken into consideration, the results from the AFM filter was quite remarkable.

Trials are now being planned to use AFM in moving bed sand filters in comparative trials. It is expected that AFM will allow moving bed filters to be used in applications previously considered not suitable. For example, waste water with high BOD levels and solids load. AFM does not become biofouled, and will remove much smaller particles from the water than can be achieved by using sand, the improvement in performance is anticipated to be substantial.

	Suspended solids
	inlet	AFM	sand
26/05/2004	32	5	8
27/05/2004	29	5	5
03/06/2004	23	7	3
04/06/2004	13	3	4
08/06/2004	28	12	32
09/06/2004	27	15	11
10/06/2004	27	13	7
11/06/2004	16	11	9
17/06/2004	33	3	7
18/06/2004	39	16	18
22/06/2004	70	15	10
23/06/2004	61	8	5
30/06/2004	39	4	12
01/07/2004	37	6	6
06/07/2004	45	54	17
07/07/2004	30	16	20




	Ammonium
	Inlet	AFM	sand
26/05/2004	1.6	1.4	0.9
27/05/2004	1.5	1.2	0.5
03/06/2004	0.9	0.67	0.52
04/06/2004	0.93	0.39	0.3
08/06/2004
09/06/2004	1.6	1	0.55
10/06/2004	1	0.63	0.53
11/06/2004	0.98	0.63	0.64
17/06/2004	0.88	0.89	0.6
18/06/2004	0.96	0.82	0.77
22/06/2004	0.55	1.2	1
23/06/2004	1.2	0.31	0.46
30/06/2004	0.8	0.6	0.7
01/07/2004	0.9	0.7	0.8
06/07/2004	0.92	1.1	0.76
07/07/2004	1.4	0.83	0.84


	BOD
	inlet	AFM	sand
26/05/2004	11	4	7
27/05/2004	11	4	6
03/06/2004	14	8	8
04/06/2004	8	3	4
08/06/2004	17	7	6
09/06/2004	10	6	8
10/06/2004	15	4	6
11/06/2004	13	5	5
17/06/2004	14	7	6
18/06/2004	20	9	11
22/06/2004	25	11	9
23/06/2004	27	11	8
30/06/2004	6	7	2
01/07/2004	15	7	5
06/07/2004	21	13	10
07/07/2004	13	7	9


	COD
	inlet	AFM	sand
26/05/2004	99	60	65
27/05/2004	78	43	50
03/06/2004	75	49	44
04/06/2004	58	36	36
08/06/2004	98	66	67
09/06/2004	82	61	74
10/06/2004	86	51	53
11/06/2004	69	64	74
17/06/2004	75	47	45
18/06/2004	120	68	72
22/06/2004	130	68	62
23/06/2004	120	45	48
30/06/2004	110	55	58
01/07/2004	89	55	47
06/07/2004	110	75	76
07/07/2004	81	58	59