Dear Jacky,

I would like to circulate the general information out of which a part is the answer for Chrstie's question.

Christie wrote:
>Could you please brief me on the composition of what is accepted as
>Liquid N03-fertilizer (i.e the concentration limits of NO, NH4, P & SS,etc)
>from a nitrified effluent.

In this connection, we would like to convey you the following information (Source: The Biogas Technology in China, BRTC, China, 1989).

Nutrients                       Inhibitory concentration

NH4                             above 200 mg/litre
NO3                             above   50 mg/litre
Copper (cu++)                   above 100 mg/litre
Chromium (Cr+++)                above 200 mg/litre
Nickel (Ni++)                   200-500 mg/litre
Potassium (K+)                  2500-4500 mg/litre
Calcium (Ca++)                  2500-4500 mg/litre
Magensium (Mg++)                1000-1500 mg/litre
Sodium Chloride                 40,000 ppm
Sulphate                        5,000 ppm

Best regards!