The invention relates to the field of
wastewater treatment, in particular to a zero
discharge system for high-efficiency low-cost desulfurization
wastewater treatment of a
coal-fired power
plant. Thezero
discharge system comprises a pretreatment unit, a concentration reduction unit and a
tail end curing unit, the pretreatment unit is used for removing suspended matters,
fluoride,
sulfide and heavy
metal ions in the
wastewater through
flocculation reaction, reducing chemical
oxygen consumption and
ammonia nitrogen and effectively adjusting the pH value; pretreated water of the pretreatment unit is treated by the concentration reduction unit in a direct
contact type thermal concentration mode, obtained wet
flue gas enters a desulfurizing
tower to be treated, obtained precipitated mud entersa
tail end solidification unit, and obtained mud supernatant strong brine circularly enters the concentration reduction unit to be treated; after mixing of a
tail end curing unit precipitated slurrywith
fly ash, quick
lime,
ferrous sulfate and an inorganic polymerizing agent, a low-grade
building material if formed.
Flue gas
waste heat is used for concentrating desulfurization wastewater, the inlet
flue gas temperature of the desulfurization
tower is reduced, and the
evaporation water consumption of the desulfurization
tower is reduced; the wastewater
recovery rate is high, and the water-saving purpose is achieved.