Abstract: The invention relates to an apparatus for the purification of a liquid effluent containing pollutants, particularly metals and/or radionuclides, as well as to a process for purifying the effluent.An object of the invention is to provide a continuously functioning purifying apparatus.This object is achieved with the aid of an apparatus incorporating a confinement enclosure containing a support in which are immobilized living cells of photosynthetic microorganisms. The support is made from a material transparent to light rays. The apparatus also incorporates a mechanism for introducing and circulating the effluent to be treated and a culture medium within the enclosure.

Abstract: An apparatus for the automatic, continuous cleaning of the pipe of a solar receptor of a photobioreactor also having a carbonator associated with the solar receptor. The solar receptor and the carbonator both being traversed in series in a closed loop by a nutrient medium solution. A branch duct being provided between an outlet and an inlet of the solar receptor to permit a circulation of cleaning balls therebetween. The apparatus including a motorized valve on a vertical portion of the branch duct for bringing about the automatic passage of the balls with the exclusion of the solution, as well as a pivoting sleeve placed in the inlet of the solar receptor, downstream of the junction with the branch duct. The sleeve serving as a support for a controllable manual valve and permitting the introduction or removal of cleaning balls with respect to the pipe.

Abstract: Apparatus for the intensive, controlled production of microorganisms by photosynthesis.This apparatus comprises at least one photobioreactor (6) to be placed on an expanse of water (8), which has first group of flexible tubes (38), which are transparent to light and in which circulates the culture medium and a second group of inflatable tubes (62), disposed and maintained beneath the first group by means of detachable Y-shaped interpolated members (70), which are regularly spaced. At least one two-column carbonator (12) connected to the photobioreactor intake (43) for charging the liquid medium with the CO.sub.2 necessary for photosynthesis is provided. Two degassing means (36) connected to the two ends of the photobioreactor are provided for eliminating the oxygen produced by the microorganisms from the liquid medium. There is at least one expansion tank (2) connected to the photobioreactor (6) for reducing possible volume variations in the photobioreactor (6).