Аutomation
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The automation of the BIOTAL Plant of a capacity of 1 to 10 m3/24-hour-period ensures four direct links and three feedback links:
- direct links:
- compressor control;
- control of electric magnetic valve for pumping out treated waste waters;
- control of electric magnetic valve for separation of surplus active sediments;
- control of electric magnetic valve for filter cleaning (if there is such);
- feedbacks:
- receiving signals from the level indicator, which is responsible for switching the system into First (after 1 hour) and Second (after 24 hours) Economy Mode of Operation;
- receiving signals from the level indicator, which is responsible for switching the system into a Forced Mode of Operation when the waste water quantity exceeds the design quantity;
- receiving signals from the system active sediment quantity control indicator, which is responsible for switching airlift (16) electric magnetic valve, which separates the surplus sediments to the sediment tank in case the determined active sediment quantity is exceeded.
There are five waste water treatment phases in the system: mixing in an anaerobic environment, aeration of sediment mixtures, settling, pumping out of the treated waste waters and pumping out of surplus sediments.
Mixing Phase: it is carried out in all three SBR Reactors by periodic short (to ensure that the oxygen in the sediment mixtures does not exceed 0,5 ml/l) start-up of aerators. During the period of the short start-up of aerators there is also re-circulation of sediment mixtures between the three reactors. The running time and the idle time are set during the automation set-up.
Aeration phase: there is aeration in all three SBR Reactors with a simultaneous re-circulation of sediment mixtures between the reactors. Controllable airlift (13) during the preceding cycles has reduced the level in Reactors І and ІІ, thus creating first and second accumulating reservoirs. The waste waters arriving into the system are collected in these reservoirs during the phases of mixing, aeration, pumping out of treated waste waters and surplus sediments. In its turn, controllable airlift (15), during the phase of pumping out of the treated waste waters, reduces the water level in the third SBR Reactor, thus creating a third accumulating reservoir. All these three accumulating reservoirs collect the arriving waste waters during the mixing and aeration phases of the system. Thanks to these accumulating reservoirs, the sediment mixture does not get into the tertiary settling tank until the settling process is completed in the third SBR Reactor and then the treated waste waters are pumped out by airlift (15) into the tertiary settling tank during the treated water pumping-out phase.
Settling Phase: during this phase (in BIOTAL Plants from 1 to 10 m3/24-hour-period) all elements are switched off. The third SBR Reactor switches into a Mode of Operation as a secondary settling tank, while the arriving waste waters are collected in the accumulating reservoirs of the first and second Reactors.
Treated Waste Water Pumping-out Phase: during this phase the treated waste waters are pumped out by airlift (15) from the third SBR Reactor to tertiary settling tank ІV, accompanied with aeration in І and ІІ SBR Reactors.
Surplus Active Sediment Pumping-out Phase: this phase (in BIOTAL Plants from 1 to 10 m3/24-hour-period) begins at the same time with the Treated Waste Water Pumping-out Phase but it is shorter. The surplus active sediments are pumped out either into a special reservoir connected to the receiving chamber by a spillway for the sediment surplus water, or into filter bags, which are drained in ІІ SBR Reactor.
- direct links:
- compressor control;
- control of electric magnetic valve for pumping out treated waste waters;
- control of electric magnetic valve for separation of surplus active sediments;
- control of electric magnetic valve for filter cleaning (if there is such);
- feedbacks:
- receiving signals from the level indicator, which is responsible for switching the system into First (after 1 hour) and Second (after 24 hours) Economy Mode of Operation;
- receiving signals from the level indicator, which is responsible for switching the system into a Forced Mode of Operation when the waste water quantity exceeds the design quantity;
- receiving signals from the system active sediment quantity control indicator, which is responsible for switching airlift (16) electric magnetic valve, which separates the surplus sediments to the sediment tank in case the determined active sediment quantity is exceeded.
There are five waste water treatment phases in the system: mixing in an anaerobic environment, aeration of sediment mixtures, settling, pumping out of the treated waste waters and pumping out of surplus sediments.
Mixing Phase: it is carried out in all three SBR Reactors by periodic short (to ensure that the oxygen in the sediment mixtures does not exceed 0,5 ml/l) start-up of aerators. During the period of the short start-up of aerators there is also re-circulation of sediment mixtures between the three reactors. The running time and the idle time are set during the automation set-up.
Aeration phase: there is aeration in all three SBR Reactors with a simultaneous re-circulation of sediment mixtures between the reactors. Controllable airlift (13) during the preceding cycles has reduced the level in Reactors І and ІІ, thus creating first and second accumulating reservoirs. The waste waters arriving into the system are collected in these reservoirs during the phases of mixing, aeration, pumping out of treated waste waters and surplus sediments. In its turn, controllable airlift (15), during the phase of pumping out of the treated waste waters, reduces the water level in the third SBR Reactor, thus creating a third accumulating reservoir. All these three accumulating reservoirs collect the arriving waste waters during the mixing and aeration phases of the system. Thanks to these accumulating reservoirs, the sediment mixture does not get into the tertiary settling tank until the settling process is completed in the third SBR Reactor and then the treated waste waters are pumped out by airlift (15) into the tertiary settling tank during the treated water pumping-out phase.
Settling Phase: during this phase (in BIOTAL Plants from 1 to 10 m3/24-hour-period) all elements are switched off. The third SBR Reactor switches into a Mode of Operation as a secondary settling tank, while the arriving waste waters are collected in the accumulating reservoirs of the first and second Reactors.
Treated Waste Water Pumping-out Phase: during this phase the treated waste waters are pumped out by airlift (15) from the third SBR Reactor to tertiary settling tank ІV, accompanied with aeration in І and ІІ SBR Reactors.
Surplus Active Sediment Pumping-out Phase: this phase (in BIOTAL Plants from 1 to 10 m3/24-hour-period) begins at the same time with the Treated Waste Water Pumping-out Phase but it is shorter. The surplus active sediments are pumped out either into a special reservoir connected to the receiving chamber by a spillway for the sediment surplus water, or into filter bags, which are drained in ІІ SBR Reactor.