Using dewatered sludge from sewage treatment plant and fly ash, clay as raw materials, sludge ceramsite was prepared through mixing in an appropriate ratio and high-temperature sintering. The adsorption law of Ni~(2+) on sludge ceramsite was studied. The results show that, with increasing of adsorption time, adsorption capacity of sludge ceramsite to metal ions increases, Ni~(2+) adsorption time to reach the equilibrium is 140 min, the corresponding maximum adsorption is 0.001 64 mg/g. Thermodynamic study r...