Abstract: A method for removing a heavy metal from water includes subjecting a microbial solution containing a liquid culture of a urease-producing bacterial strain and a reaction solution containing a manganese compound and urea to a microbial-induced precipitation reaction, so as to obtain biomineralized manganese carbonate (MnCO3) particles, admixing the biomineralized MnCO3 particles with water containing a heavy metal, so that the biomineralized MnCO3 particles adsorb the heavy metal in the water to form a precipitate, and removing the precipitate from the water.

Abstract: The present invention provides a rotary engine having: a stationary cylinder with an intake aperture, an exhaust aperture, and an ignition aperture on the surface; a driving disk disposed inside the stationary cylinder connected to an external driving source through a shaft, the driving disk being secured to a surface of at least one rotational cylinder that are together driven by the driving source; and a swing piston installed inside the rotational cylinder driven by a driving member to move within the rotational cylinder to alter the intake and exhaust volume of the rotational cylinder. The intake and exhaust volume changes corresponding to the position of the rotational cylinder which follows the intake, ignition, and exhaust sequential process to complete the intake, compression, combustion, and exhaust cycle of an engine to create a simple yet high output, low-friction engine with superior cooling.