Wastewater C,N,P
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In the A/O process, why should the ratio of C, N, and P in wastewater be around 100:5:1? Does the reflux ratio refer to the ratio of the amount that returns from pool O to pool A to the feed amount? The pH of the incoming water is 7.8; what is the optimal pH for anaerobic conditions?
This post was last edited by ray1513 on 2012-4-3 09:56. The optimal pH for anaerobic conditions is 6.8–7.0, while the pH of the effluent is 7.2–7.5:$
This post was last edited and replied to by ray1513 on 2012-4-3 09:56. Reply to 2# ganchinghua: Isn’t anaerobic digestion a nitration process? Then why is the pH of the effluent still high? By \"effluent,\" do you mean the water after treatment?
This post was last edited by ray1513 on 2012-4-3 09:57. Reply to 1#: Shouhou – it’s not the C,N,P ratio; rather, it’s BOD5:N:P=100:5:1. This ratio is related to the composition of activated sludge, whose molecular formula can be expressed as C60H87O23N12P. Moreover, the longer the sludge age, the lower the requirements for nitrogen and phosphorus. The understanding of the reflux ratio is correct.:lol
This post was last edited and replied to by wgh11231123 on 2011-7-20 at 20:20. Reply 3# Shouhou: Anaerobic conditions are involved in the denitrification process, and the pH value of the effluent will increase slightly. If the influent load increases, it will activate the acidification stage while suppressing the methanogenesis stage, thereby causing acid accumulation and a decrease in pH value ； If the influent load is reduced significantly, insufficient nutrients will be available in the methanogenesis stage later on, leading to self-decomposition and an increase in suspended solids and pH in the effluent.
This post was last edited and replied to by ray1513 on 2012-4-3 09:57. Reply to 2# ganchinghua: The optimal pH value for anaerobic conditions is 6.8–7.2, and the pH value of the effluent should also be at this level. The anaerobic system must maintain a certain level of alkalinity to mitigate the impact of the acidification phase on the pH value of the entire treatment system.
The nitration process occurs under aerobic conditions. :$
You mean that low raw water concentration and low water inflow lead to malnutrition. Methanogens break it down, causing an increase in SS and pH?:$
This post was last edited by ray1513 on 2012-4-3 09:57. Reply to 8# ganchinghua: Prolonged nutrient deficiency can lead to the degradation of methanogenic bacteria. If stored at lower temperatures, enzyme activity is reduced, but it is still possible to maintain activity for several months or even longer. I was once in charge of the operation of sugar production wastewater treatment; they used the IC process there. In 2009, the production volume was relatively low, and the amount of granular sludge added was twice the actual required amount. At that time, the amount of sludge was around 300 cubic meters, while the total volume of the IC system was about 700 cubic meters. After operating it for three to four months, it was observed that the sludge amount decreased very rapidly, dropping to around 220 cubic meters. The various parameters of the treated water were still within normal ranges, except that sometimes there was suspended solid present, as well as sludge that appeared whitish in color (normal granular sludge is black). The pH value was also acceptable. The reason for this was that pretreatment processes such as hydrolysis and acidification were used before the IC process, which helped to keep the pH value inside the IC tower at a normal level.