Trickling filter

About: Trickling filter is a research topic. Over the lifetime, 1098 publications have been published within this topic receiving 20219 citations.

The role of the trickling filter in sewage purification.

Abstract: The introduction of the activated sludge process, about a quarter of a century ago, revolutionized sewage purification concepts and, for a while, threatened to relegate the trickling filter to a minor role in sewage treatment, if not to displace it entirely. Twenty-five years of experience has indicated, however, that the trickling filter has certain virtues which, under some conditions, may render it useful and effective where the activated sludge process is doomed to failure. Necessity for finding some method of successfully treating creamery wastes from small Iowa dairies soon taught us that marked fluctuations in the con centration of creamery wastes tended to seriously disturb and dis rupt the purifying functions of the activated sludge floe, whereas the trickling filter (probably because its upper layers serve as a sort of equalizing and storage mechanism, thereby partially protecting the lower purifying zones against sudden changes) was found to be much more applicable for treatment of this industrial waste. The change of concept as to criteria of purification also played a vital role in the revival of interest in trickling filters. In the conventional sewage treatment plant, consisting of sedimen tation followed by trickling filters, the action in the settling tank was looked upon as primarily, and in a sense exclusively, mechanical. Such biological action as might take place in the settling tank was considered incidental and more recently it has been recognized that any appreci able biological action would be detrimental, so that chlorination was introduced to reduce such activity to a minimum and, if possible, to arrest it entirely. The filter, on the other hand, was looked upon as a purely biological agent and its mechanical agglomeration functions were either disregarded or minimized so that the efficiency of the trickling filter was evaluated primarily upon the degree of mineraliza tion effected, as measured by nitrification. A highly nitrified effluent can be attained only through aerobic biological oxidation. The intro duction of the criterion of oxygen demand reduction (which could be effected by physical and chemical as well as biological agencies) as a measure of purification efficiency, made possible utilization of the trickling filter's capacity for such physico-chemical reductions in B.O.D. This new emphasis on the nature of the desired accomplish ment in sewage treatment served to bring filters back into the picture of sewage purification, as it was recognized that properties other than

Sulfur dioxide desorption experimental equipment

Abstract: The utility model discloses sulfur dioxide desorption experimental equipment which comprises a sulfur dioxide tank, a nitrogen tank, a gas mixing tank connected with the sulfur dioxide tank and the nitrogen tank, a first trickling filter tower of which the bottom is connected to an outlet of the gas mixing tank, a first liquid storage tank which is connected with a sprinkle head at the top end inside the first trickling filter tower, a second trickling filter tower of which the bottom is connected with an outlet in the top of the first trickling filter tower, and a second liquid storage tank connected with a sprinkle head at the top end inside the second trickling filter tower. The utility model provides an experiment device, wherein multiple nutrient liquid can be sprayed to sulfur dioxide, and thus the sulfur dioxide desorption effect can be observed.