Trickling filter

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

Development of natural treatment system consisting of black soil and Kentucky bluegrass for the post-treatment of anaerobically digested strong wastewater

Abstract: To develop a sound post-treatment process for anaerobically-digested strong wastewater, a novel natural treatment system comprising two units is put forward. The first unit, a trickling filter, provides for further reduction of biochemical oxygen demand and adjustable nitrification. The subsequent soil–plant unit aims at removing and recovering the nutrients nitrogen (N), phosphorus (P) and potassium (K). As a lab-scale feasibility study, a soil column test was conducted, in which black soil and valuable Kentucky bluegrass were integrated to treat artificial nutrient-enriched wastewater. After a long-term operation, the nitrification function was well established in the top layers, despite the need for an improved denitrification process prior to discharge. P and K were retained by the soil through distinct mechanisms. Since they either partially or totally remained in plant-available forms in the soil, indirect nutrient reuse could be achieved. As for Kentucky bluegrass, it displayed better growth status when receiving wastewater, with direct recovery of 8%, 6% and 14% of input N, P and K, respectively. Furthermore, the indispensable role of Kentucky bluegrass for better treatment performance was proved, as it enhanced the cell-specific nitrification potential of the soil nitrifying microorganisms inhabiting the rhizosphere. After further upgrade, the proposed system is expected to become a new solution for strong wastewater pollution.

Design and performance of a fibrous bed bioreactor for odor treatment.

Abstract: Biological processes have become popular for odor treatment. In this study, a novel fibrous bed bioreactor was applied for treatment of odorous gas. The column reactor was packed with spirally wound fibrous sheet material on which a consortium of microorganisms selected from activated sludge was immobilized. The first stage of this work comprised a preliminary study that aimed at investigating the feasibility of the fibrous bed bioreactor for treatment of odorous volatile fatty acids (VFAs). In this stage, the performance of a fibrous bed bioreactor at increasing mass loadings ranging from 9.7 to 104.2 g/(m3.h) was studied. VFA removal efficiencies above 90% were achieved at mass loadings up to 50.3 g/(m3.h). At a mass loading of 104.2 g/(m3.h), removal efficiency was found to be 87.7%. In the second stage of the work, the process was scaled up with design and operational considerations, namely, packing medium, process condition, and configuration selections. A trickling biofilter with synthetic fibrous packing medium was selected. It was operated under countercurrent flow of gas and liquid streams. The effects of inlet concentration and empty bed retention time on bioreactor performance were studied. The bioreactor was effective in treating odorous VFAs at mass loadings up to 32 g/(m3.h), at which VFAs started to accumulate in the recirculation liquid, indicating that the biofilm was unable to degrade all the VFAs introduced. Although VFAs accumulated in the liquid phase, the removal efficiency remained above 99%, implying that the biochemical reaction rate, rather than gas-to-liquid mass transfer rate, was the limiting factor of this process. The bioreactor was stable for longterm operation; no clogging and degeneration of the packing medium was observed during the 4-mo operation.

Method of obtaining methyl alcohol from raw gas and installation for carrying out said method

Abstract: In a first purification stage (1) hydrogen sulfide contained in the raw gas is separated by microbial oxidation into water and sulfur. In a second (17) and third (32) purification stage the methane contained in the desulphurized raw gas is oxidized by further microbial oxidation to yield methyl alcohol. The first purification stage (1) comprises a first fixed trickling filter device (2), the second purification stage (17) comprises a second fixed trickling filter device (18) and the third purification stage (32) comprises a third fixed trickling filter device (33). The first fixed trickling filter device (2) contains microorganisms which carry out the oxidation of H2S into sulfur. The second (18) and third (33) fixed trickling filter devices contain a mixed population of bacteria and yeasts which primarily carry out the oxidation of the methane. The wash water emerging from the wash water bottom (36) of the third purification stage (32) is filtered in a filter press (44). The filtrate flows through a microfilter device (49) and enters the distillation column (50). The distillation vapour precipitates in a condenser (51) and the distillate is collected in a product tank (52). This distillate has a methanol content of between 30 and 40 %.