The invention discloses a municipal
sludge reduction method. The method includes the steps of: 1) introducing municipal
sludge into a
sludge concentration tank for concentration, and letting the supernatant flow back to the front end of a
sewage treatment
plant; 2) introducing the concentrated municipal sludge into a biological conditioning tank I, adding
ferrous salt and
sulfur powder, conductingstirring and
aeration, and performing first-stage conditioning; 3) introducing the municipal sludge subjected to the first-stage conditioning into a biological conditioning tank II, replenishing
ferrous salt and
sulfur powder, and conducting stirring and second-stage conditioning; 4) introducing the municipal sludge subjected to the second-stage conditioning into a modification tank, adding acid,and performing modification treatment; and 5) introducing the modified municipal sludge into a diaphragm filter, adding an external
magnetic field, and performing filter pressing to obtain a
filter cake and filtrate, subjecting the
filter cake to concentrated treatment, and returning the filtrate to the sludge concentration tank. The municipal sludge reduction method provided by the invention hasthe advantages of small
reagent dosage, low
energy consumption, simple treatment process, good sludge reduction effect and the like, and can reduce the
water content of sludge to 50% or below.