Trickling filter

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

Biological fixed-film systems

Abstract: This paper includes reports on several biological fixed film systems in wastewater and hazardous waste treatment. Biological treatment of a refinery wastewater was studied in a rotating biological contactor (RBC) unit coupled with polyurethane foam (PUF) as a porous biomass support attached on both sides of the biodisks. The RBC-PUF bioreactor exhibited better performance than conventional RBCs for the removal of chemical oxygen demand (COD), NH{sub 3}-N, phenol, hydrocarbons, and suspended solids because of higher concentrations of active biomass. Successful performance of an anaerobic-aerobic treatment process using a combination of RCBs with activated sludge was achieved for treating a dye wastewater. Two high-rate trickling filters, cross-flow (CF) and vertical flow, were examined over a two year period for biological treatment of seafood processing wastewater. Results suggested superior performance of CF plastic media with substrate removal following a pseudo half-order kinetic reaction. Submerged structured packings in biofilm reactors were tested and characterized for a wide range of applications. Their efficiency was discussed in terms of contaminant removals and SS retention.

Biologically enhanced oxygen transfer in a fixed-film system

Abstract: Mecanisme d'augmentation du transfert d'oxygene base sur le transfert a l'interface du lit bacterien. Description quantitative du phenomene

Selected organic pesticides, occurrence, transformation, and removal from domestic wastewater.

Abstract: Chlorinated hydrocarbon pesticides (chp) and chlorophenoxy herbicides (cph) are two groups of compounds that have contaminated the aquatic environment as a result of their widespread usage and persistence. Measur able concentrations of chp and cph have been detected in the nanogram per litre to the microgram per litre level in almost all major U. S. rivers and lakes.1-5 One of the potential sources of chp and cph for natural waters is domestic wastewaters. From a literature review it is apparent that studies concerned with the effectiveness of conventional and advanced wastewater treat ment processes in removing organic pesticides are few, with the result that very little is known today about the ability of wastewater treatment processes such as activated sludge or trickling filters to remove these pesticides and herbicides. This paper presents a study performed on the occurrence, transformation, and removal of chp and cph from Dallas, Tex., municipal wastewater. A 3 785-m3/d (1-mgd) water reclamation pilot plant was used for this study. The pilot plant, built in 1969 by the city of Dallas, was designed to study the effectiveness of different sequences of unit processes in producing high quality effluent and includes two completely mixed activated sludge units (aeration basins and final clarifiers), a chem ical treatment module, two mixed-media filters, and two activated carbon columns. The in fluent to the pilot plant was derived from three different points in Dallas' White Rock Waste water Treatment Plant (WRWTP): second stage filter effluent prior to final clarification, final effluent prior to chlorination, and primary effluent. WRWTP is a 204 000 m3/d (54-mgd) high-rate, two stage trickling filter facility. From 1972 to 1975, a research program was conducted to investigate the feasibility of wastewater recycling processes. Active par ticipants in this program included the civil engineering department of Texas A&M Uni versity, the Dallas Water Utilities, and the U. S. Environmental Protection Agency (EPA). The pilot plant was operated with varying sequences of units processes, and samples from each treatment unit were subjected to an ex tensive analytical program. The analytical program included, in addition to chp and CPH, heavy metals, nutrients, viruses, and all the common water and wastewater control parameters such as pH, alkalinity, biochemical oxygen demand (bod), chemical oxygen de mand (cod), and suspended solids (ss). The study of chp and cph represents only one aspect of a broad research program designed to evaluate the performance of different se quences of unit processes. The results pre sented in this paper include the characteriza tion of domestic wastewater in terms of chp and cph and an evaluation of the effects of the activated sludge process on these com pounds. The effects of chemical and physical

Overlapping photodegradable and biodegradable organic nitrogen in wastewater effluents.

Abstract: Photochemical degradation of dissolved organic nitrogen (DON) in final effluent of trickling filter and activated sludge wastewater treatment plants (WWTPs) was studied. Inorganic N, mostly nitrite, was produced from the photodegradation of DON for samples from both WWTPs. Photodegradable DON (PDON), biodegradable DON (BDON), and overlapping photodegradable–biodegradable DON (OPBDON) were determined. BDON was associated with PDON as well as non-PDON. BDON and PDON concentrations in the final effluent samples were 4.71 and 4.62 mg N/L for the trickling filter plant and 3.95 and 3.73 mg N/L for the activated sludge plant, indicating that photodegradation is as important as biodegradation in the mineralization of effluent DON in receiving waters. OPBDON, which is more problematic in the water environment because it can be mineralized by light or bacteria or both, was 3.68 and 2.64 mg N/L (57% and 43% of total DON) in the final effluent samples from the trickling filter and activated sludge plants, respective...