NOVELTY - Soil residue, humus residue, compost residue, and bottom-sludge residue containing calcium salts generated after calcined lime neutralizes the residue after electric-power generation, as fertilizer component addition soil or soil conditioner. A suspension liquid containing acids, such as phosphoric acid, sulfuric acid, and hydrochloric acid, added to a suspension of soil, humus, compost, and bottom sludge in water, is used for electronic supply source of fuel cell by metal air battery. Also claimed is, resource circulation apparatus.    USE - For soil-pollution restoration, electric-power generation, wastewater treatment, farmland restoration, and suppressing carbon-dioxide emission (all claimed).    ADVANTAGE - The method enables efficient restoration of soil pollution and environmental preservation.    DETAILED DESCRIPTION - Soil residue, humus residue, compost residue, and bottom-sludge residue containing calcium salts, such as calcium phosphate, calcium sulfate, and calcium chloride generated after calcined lime neutralizes the residue after electric-power generation, as fertilizer component addition soil or soil conditioner. A suspension liquid containing acids, such as phosphoric acid, sulfuric acid, and hydrochloric acid, added to a suspension of soil, humus, compost, and bottom sludge in water, is used for electronic supply source of fuel cell by metal air battery. Also claimed is, resource circulation apparatus. INDEPENDENT CLAIMS are included for the following:    (1) soil-bottom-sludge electricity repair apparatus and method which involves drawing and removing toxic ionic substances, such as cadmium, to an electrode by making ionic harmful-substance contaminant-containing soil and bottom-sludge into component of fuel-cell electric-power generation;    (2) suppression of carbon-dioxide emission;    (3) method and apparatus which carry out farmland restoration by using as a fertilizer the calcium phosphate obtained by calcined lime neutralizing phosphoric acid after electrolyte-liquid recovery in fuel-cell electric-power generation systems using phosphoric acid as electrolyte liquid;    (4) organic-matter amount measuring method and apparatus in water quality, using silver electrode; and    (5) method and apparatus using metal electrodes other than silver electrode.