Abstract: An improved method for underwater reclamation is disclosed. Dredged mud sent under pressure by an earth and sand conveying device is treated with solidifying material, and before it is solidified, it is directly fed to an underwater reclaiming apparatus. The treated mud is fed through a discharge port of the underwater reclaiming apparatus, while the discharge port is always maintained embedded at a constant depth in a previously deposited underwater reclamation mud layer at the bottom of the water. An apparatus for underwater reclamation that is suitable for practicing the improved method is also disclosed.

Abstract: A combination of a dehydration process for dehydrating sewage sludge by mixing a quicklime-containing material with the sludge, a cement conversion process for introducing the solids produced by the dehydration process into a cement kiln with other cement raw materials to yield cement, and a gas treatment process for introducing gases generated in the dehydration process into a cement burning process, thereby enabling conversion of the sewage sludge into cement without releasing wastes, with a reduction in fuel consumption for the cement burning, and a reduction in NOx content of the exhaust gas.

Abstract: There is disclosed a softy mud solidifying agent which comprises cement, and at least two members selected from the group consisting of pozzolanic substances, inorganic compounds and organic compounds. The solidifying agent is capable of solidifying dredged earth, sand, softy mud, etc. in such a manner that their mixture can be re-cast into water to form submerged banks, artificial fish-gathering places, etc., without causing water pollution.