Abstract: Process for the continuous separation of oil-in-water emulsions, which may contain surfactants, for example oil- and surfactant-containing effluents, by electrolysis, which comprises electrolysing such emulsions at a pH value of 5 to 10 and under a potential difference of at least 1.5 volts between the electrodes, optionally in the presence of a coagulating agent, with the formation of discrete oil particles, floating these oil particles with the aid of hydrogen gas formed simultaneously at the cathode, and then separating off the oily phase thus formed which is optionally condensed by the addition of flocculating agents.

Abstract: A process for purifying effluents which contain proteins, which process comprises treating said effluents with a basic polymer compound and separating the flocks that are formed from the effluent.

Abstract: An electrolytic process is used to reduce the silver content of fixer solution to a level such that it can be discharged as effluent. In the process silver is removed from aqueous fixer solutions by circulating the solution in a closed cycle through an electrolytic cell such that the residence time in the cell is not greater than one minute for each passage. The electrode loading is within the range between 5 and 15 mA/cm.sup.2 initially but is reduced in at least one further chronologically consecutive stage. Exhausted developer solution may be added to the fixer solution to act as a pH controlling redox system.

Abstract: A device for sampling fluid is provided which comprises a plurality of sample vessels uniformly spaced apart in a circle and means for the alternate feeding of fluid into the individual sample vessels. A buffer vessel whose volume is at least three to five times greater than that of each individual sample vessel is connected upstream in series to the sample vessels. The sample vessels are U-shaped and have two substantially upright tubular arms which are joined together at their bottom ends. One arm is smaller in diameter and ends below the opening of the other arm or has a mouth or opening below the opening of the other arm. The means for feeding the fluid enter the thicker and higher arm of the sample vessels and are so built as to be able to empty the entire contents of the buffer vessel in the course of at most one to two minutes into the sample vessel.