The influence of wastewater type and organic loading on the protozoan and metazoan population of a peat bed filter

Three peat bed filters treating wastewaters with differing proportions of industrial input were compared experimentally by analysis of their population structure. The plants were all full scale and served village communities around Madrid, Spain. AH three plants showed a high ciliated protozoan population density (> 105/1), but the least loaded system, which received only domestic wastewater, exhibited a 10 fold greater abundance and a predominance of Paramecium. The plants with an industrial input performed less well and showed a population structure predominated by Chilodonella and Colpidium as well as having substantial populations of nematodes and rotifers. Protozoans may contribute towards an enhanced BOD and COD removal efficiency and can be used as indicators of optimum oxygenation conditions with the peat bed

The population structure of a peat filter bed system for treating domestic wastewater, and comparisons with conventional activated sludge

The protozoan population growing in a peat filter bed located at an urban wastewater treatment plant ("La Cabrera”;, Madrid, Spain) was studied. A high density of microorganisms (2.7106 No./l) was found indicating a considerable biological activity. Comparing the mean characteristics of the protozoan population of a peat filter bed with that of a conventional activated-sludge pilot plant, it was found that 80% of the total population corresponded to free swimming ciliates in the first case, whilst sessile or fixed ciliates dominated in the activated-sludge system. These differences in population structure between purification systems could indicate, that the ciliate population in the peat bed did not reach an equilibrium phase, due to the relatively short operation time used in a pond (25-30 days), and was more similar to the transitional phase in an activated-sludge system. Paramecium sp. was found to be the predominant ciliate in the peat bed although a reasonably diverse population structure was found, which was indicative of aerobic conditions

Additional file 2: of Risk factors for revision of total knee arthroplasty: a scoping review

Characteristics of Included Studies. [16–20, 27–34, 35–37, 38–44, 55–65]. (DOCX 70 kb

Additional file 1: of Risk factors for revision of total knee arthroplasty: a scoping review

Search Strategy. (DOCX 14 kb