Abstract: A system, that may be portable, for purifying liquid flowing gravitationally from a source/reservoir into a purified liquid receptacle is described. The system includes a housing with a generally horizontal filtering space. More than one liquid inlet disposed at a top portion of the filter is provided as well as one or more liquid outlets disposed at a bottom portion. The liquid flows in a generally lateral direction through the liquid treatment medium. Two or more first walls extending upwardly into the filtering space from a bottom wall thereof and ending with an apex are provided inside the device. One or more second walls downwardly extending into the filtering space from a top wall thereof are also provided. Each of the walls defines a closed path. The first and second walls jointly cause the liquid to flow in a curvilinear flow path from the inlet to the outlet.

Abstract: The present subject matter provides a filter medium for filtering aqueous solutions, particularly water for human and animal consumption. The medium may be employed in a great variety of filters of various sizes and constructions.

Abstract: A water treatment device and method for treating a quantity of water is powered by gravitational flow. The device includes an upper collecting chamber (14) and a filtration chamber (18). The filtration chamber includes a set of reactance containg at least three components wherein one of the components is a polycation and another one of the components is a polyanion. The method includes subjecting the water to gravitational flow through the filtration chamber (18).