The activated sludge settles in the secondary settlement tank and collects at the bottom. The collected sludge is removed and taken back to the aeration tank as return activated sludge, or is conveyed to the digesters as surplus activated sludge. Digestion is the last station of the biological treatment stage. The sludge is stabilized in the digester. Stabilization is understood to mean the most advanced anaerobic degradation of organic compounds with the aid of specific bacteria. These bacteria convert the organic components of the anaerobic digested sludge to biogas.
To survive in the digester, the bacteria need a constant temperature of 35 to 37 ºC. This means that it is absolutely essential to monitor the temperature in the digester. The JUMO PROCESStemp RTD temperature probe with ATEX approval and the JUMO di 308 digital indicator are exactly the right products for this. Additional measurement variables to monitor are the liquid level and the pressure in the digester. The JUMO dTRANS p20 pressure transmitter and the JUMO dTRANS p33 level measurement probe are the ideal solution for measuring the pressure and liquid level in explosion-risk areas. To monitor measurements, you can connect your measuring points to the JUMO LOGOSCREEN nt recorder.