The Effect of Substrate Variation on Biofilm Growth for Use in Wastewater Treatment

The formation of biofilms on surfaces exposed to water has had significant impacts on wastewater treatment technology. Biofilms are used advantageously in wastewater treatment as rotating biological contractors to degrade harmful organic and inorganic materials. However, biofilm formation on equipment designed to inspect water quality, such as a passive sampler, can alter calculated pollution concentrations. This project investigates the effect of salt and heavy metals on a slowly rotating biological contactor and the effect of a strong magnetic field on a quickly rotating biological contactor. The extent of biofouling on a passive sampler is also examined

Review on Process, Application and Performance of Rotating Biological Contactor (RBC)

Abstract- The rotating biological contactor is an attached growth biological treatment used in removal of biodegradable matter present in wastewater is popular due to its simplicity low energy requirement, low land requirement, stable in various shock loading and recirculation not required and low hydraulic retention time. This review paper focuses on various controlling parameter of RBC like organic loading, hydraulic retention time, speed of rotation, dissolve oxygen, staging, temperature, submergence etc. The paper also highlights on the performance studies of RBC for different types of wastewater. Index Terms- Rotating biological contactor, organic loading, speed of rotation, dissolves oxygen, staging and submergence. A I

Rotating biological contactors for wastewater treatment - A review

Rotating biological contactors (RBCs) for wastewater treatment began in the 1970s. Removal of organic matter has been targeted within organic loading rates of up to 120 g m−2 d−1 with an optimum at around 15 g m−2 d−1 for combined BOD and ammonia removal. Full nitrification is achievable under appropriate process conditions with oxidation rates of up to 6 g m−2 d−1 reported for municipal wastewater. The RBC process has been adapted for denitrification with reported removal rates of up to 14 g m−2 d−1 with nitrogen rich wastewaters. Different media types can be used to improve organic/nitrogen loading rates through selecting for different bacterial groups. The RBC has been applied with only limited success for enhanced biological phosphorus removal and attained up to 70% total phosphorus removal. Compared to other biofilm processes, RBCs had 35% lower energy costs than trickling filters but higher demand than wetland systems. However, the land footprint for the same treatment is lower than these alternatives. The RBC process has been used for removal of priority pollutants such as pharmaceuticals and personal care products. The RBC system has been shown to eliminate 99% of faecal coliforms and the majority of other wastewater pathogens. Novel RBC reactors include systems for energy generation such as algae, methane production and microbial fuel cells for direct current generation. Issues such as scale up remain challenging for the future application of RBC technology and topics such as phosphorus removal and denitrification still require further research. High volumetric removal rate, solids retention, low footprint, hydraulic residence times are characteristics of RBCs. The RBC is therefore an ideal candidate for hybrid processes for upgrading works maximising efficiency of existing infrastructure and minimising energy consumption for nutrient removal. This review will provide a link between disciplines and discuss recent developments in RBC research and comparison of recent process designs are provided (Section 2). The microbial features of the RBC biofilm are highlighted (Section 3) and topics such as biological nitrogen removal and priority pollutant remediation are discussed (Sections 4 and 5). Developments in kinetics and modelling are highlighted (Section 6) and future research themes are mentioned

PENGARUH NUTRISI BAKTERI Pseudomonas sp DALAM ROTATING BIOLOGICAL CONTACTOR (RBC) TERHADAP KANDUNGAN BOD DAN COD AIR LIMBAH KILANG PARAXYLENE

Air Limbah pabrik perminyakan adalah air yang masih mengandung sedikit minyak, suspended solid, BOD dan COD yang relative masih tinggi. Penelitian ini bertujuan memperoleh hasil analisa air limbah outlet Rotating Biological Contactor (RBC) yang memenuhi standar KEP. 09 / MENLH/4/1997 khususnya kandungan BOD dan COD .Proses reduksi BOD dan COD terjadi di rotating biological contactor (RBC) oleh bakteri Pseudomonas. Pada penelitian ini digunakan variabel tetap flow rate air limbah 7 m3/jam, kecepatan putaran RBC 2,12 rpm sedangkan variable berubahnya adalah injeksi urea (1,1.1,1.2 kg/day) dan phospat (0.2,0.3,0.4 kg/day) kedalam RBC. Air limbah outlet RBC dianalisa setiap hari dengan metode API method 728-53. Dari hasil penelitian diketahui bahwa terjadi penurunan BOD dan COD di air limbah setelah diinjeksi urea dan phospat di RBC. Injeksi yang memberikan hasil terbaik dalam penelitian ini adalah urea 1.2 kg dan phospat 0.4 kg, untuk BOD terjadi penurunan dari rata-rata 166 ppm menjadi 97 ppm, untuk COD terjadi penurunan rata-rata 272 ppm menjadi 198 ppm. Kata kunci: Rotating Biological Contactor, BOD, COD, Urea, Phospa

Increased salinity improves the thermotolerance of mesophilic nitrification

Nitrification is a well-studied and established process to treat ammonia in wastewater. Although thermophilic nitrification could avoid cooling costs for the treatment of warm wastewaters, applications above 40 A degrees C remain a significant challenge. This study tested the effect of salinity on the thermotolerance of mesophilic nitrifying sludge (34 A degrees C). In batch tests, 5 g NaCl L-1 increased the activity of aerobic ammonia-oxidizing bacteria (AerAOB) by 20-21 % at 40 and 45 A degrees C. For nitrite-oxidizing bacteria (NOB), the activity remained unaltered at 40 A degrees C, yet decreased by 83 % at 45 A degrees C. In a subsequent long-term continuous reactor test, temperature was increased from 34 to 40, 42.5, 45, 47.5 and 50 A degrees C. The AerAOB activity showed 65 and 37 % higher immediate resilience in the salt reactor (7.5 g NaCl L-1) for the first two temperature transitions and lost activity from 45 A degrees C onwards. NOB activity, in contrast to the batch tests, was 37 and 21 % more resilient in the salt reactor for the first two transitions, while no difference was observed for the third temperature transition. The control reactor lost NOB activity at 47.5 A degrees C, while the salt reactor only lost activity at 50 A degrees C. Overall, this study demonstrates salt amendment as a tool for a more efficient temperature transition for mesophilic sludge (34 A degrees C) and eventually higher nitrification temperatures

Evaluation of treatability of high strength wastewater in a three stage-rotating biological contactor

Cheese whey effluent contains biodegradable organic compounds in the range of 40 to 80 g. L–1. In this study, a three–stage rotating biological contactor was fabricated as a bench scale experimental unit to remove organic matters from cheese whey. First, the treatability of cheese whey effluent in the three–stage rotating biological contactor (RBC) was evaluated. Then the effect of extended specific surface area (SSA) and recirculation rate on COD removal was investigated. The obtained results showed that the organic removal rate increased with an increase in loading rate, till other limiting parameters affect the process. Prior to application of the designated modifications to the system, maximum COD removal efficiency at hrts of 24 and 36 h with OLR of 50 gcod.L–1.d–1 was 90 and 92.4%, respectively. The removal efficiency was improved as a result of increasing the SSA and recirculation rate. Also, recirculation rate may assist to increase the DO level of the wastewater, especially at high olrs. To sum up, obtained results showed that whey effluent has been efficiently treated in a continuous operation of bench scale RBC. First published online: 26 Jun 201

Biodegradation of 2-fluorophenol in a rotating biological contactor

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Rotating biological contactors : a review on main factors affecting performance

Rotating biological contactors (RBCs) constitute a very unique and superior alternative for biodegradable matter and nitrogen removal on account of their feasibility, simplicity of design and operation, short start-up, low land area requirement, low energy consumption, low operating and maintenance cost and treatment efficiency. The present review of RBCs focus on parameters that affect performance like rotational speed, organic and hydraulic loading rates, retention time, biofilm support media, staging, temperature, influent wastewater characteristics, biofilm characteristics, dissolved oxygen levels, effluent and solids recirculation, stepfeeding and medium submergence. Some RBCs scale-up and design considerations, operational problems and comparison with other wastewater treatment systems are also reported.Fundação para a Ciência e a Tecnologia (FCT

APPLICATIONS OF ROTATING BIOLOGICAL CONTACTORSIN WASTEWATER TREATMENT

Rotating biological contactors are generally used as secondary treatment of domestic, hospital and industrial wastewater, operating asan aerobic and anaerobic fixed film biological treatment. Rotating biological contactors areeffective in the removal of biodegradable matter,pathogenic bacteria,nitrogen, recalcitrant compounds, heavy metals,emerging contaminants, and dyes from wastewater. In this paper, we present the design and operating principles of rotating biological contactors, and we review some of the most important results related to the applications of rotating biological contactors for the treatment of wastewater originating from different activities