Biological Filter Process Research Articles

생물학적 질소 제거를 위한 생물담체 공정의 최근 동향 – 리뷰

Biological nitrogen (N) removal with the bio-media process has been the preferred technology and recent developments in this technology have focused on improving N removal. However, integrated fixed film activated sludge, external nitrification, membrane, aerobic granulation BNR systems and more efficient N removal bioprocesses have been developed nowadays. To achieve N removal more efficiently, methods of nitrification and denitrification have been developed by preventing nitrate formation and enforcing nitrification-denitrification over nitrite. The process requires less oxygen and organics than nitrification-denitrification over nitrate allowing lower N concentrations to be achieved for the same influent organic’s concentration and oxygen supply. Biological filtration process using the bio-media technique that utilizes micro-organisms to remove nutrients from the wastewater. A recent study has been shown that various bio-media efficiently used for the nitrification-denitrification process, also the growth of biofilm is the potential for ammonia removal. Moreover, this technology applies to a wide range and effective in removing up to 90-95% nutrients from the effluents. Therefore, the specific surface area of bio-media is available for bio-film growth depends on media types. The main purpose of this review paper is to study the application and performance of different bio-media and their removal efficiency using biological biofilm process.

Denitrification mechanism and artificial neural networks modeling for low-pollution water purification using a denitrification biological filter process

Low-pollution water treatment is an important process for improving surface water quality. In the present study, a denitrification biological filter (DNBF) was used to treat synthetic low-pollution water, representing the typical water present in a heavily polluted urban seasonal river. The feasibility of alkali treated corncob as a denitrification slow-release carbon source was investigated. Furthermore, the performance of DNBF with different media (ceramsite, quartz sand and polypropylene plastics) and operating conditions was studied. The DNBF denitrification mechanism was analyzed and an artificial neural network model was established to predict the water quality of DNBF treated low-pollution water effluent. Results showed that when the alkali treated corncob dosage was 20 g and hydraulic retention time (HRT) was 2 h, the denitrification efficiency of DNBF with ceramsite as the filter medium was highest (≥94.7% for nitrate nitrogen and ≥ 85.6% for total nitrogen), with the effluent total nitrogen concentration meeting Class IV of the Environmental Quality Standard for Surface Water (GB 3838-2002, China). The total nitrogen removal efficiency increased with increasing HRT (0.5–2.0 h) and alkali treated corncob dosage (0–20 g). The denitrification rates established for DNBF with different media were ranked in the following order: ceramsite medium DNBF > polypropylene plastic medium DNBF > quartz sand medium DNBF. The relative abundance of denitrifying bacteria was highest (10.07% for quartz sand medium DNBF, 13.92% for polypropylene plastic medium DNBF and 23.13% for ceramsite medium DNBF) in the lower layer of the DNBFs, indicating that denitrifying bacteria are concentrated in the lower layer of the up-flow DNBF. Environmental factors (nitrite nitrogen, nitrate nitrogen, water temperature and pH) were found to affect the DNBF microbial community structure. The established artificial neural network model accurately predicted the effluent nitrogen concentration in DNBF treated low-pollution water. DNBF provides a feasible system for the treatment of heavily polluted urban seasonal rivers, achieving high total nitrogen removal efficiency using a low cost and easy operation method.

Review on biological treatment of cyanobacterial toxin in natural waters

In recent years, eutrophication has not been effectively controlled and algal pollution still breaks out frequently. At the same time, the cyanobacteria and release of algal toxins have posed a serious threat to the environment and human health. In this review, the classification and main physicochemical properties of algal toxins were summarized, and the biological removal strategies of algal toxins including biological contact oxidation process, biological filter process and biological ecological coupling process and their biodegradation mechanisms were reviewed. The influence factors on biological treatment process, including operation conditions (temperature, pH and hydraulic retention time), water property and nutrient limitation factors, were analyzed. The research on the removalmechanisms of other algae toxins and the development and optimization of new biological technology were prospected to develop and improve algal toxin removal technology and ensure drin-king water safety.

Progress in Slow Sand and Alternative Biofiltration Processes

This book provides a state-of-the-art assessment on a variety of biofiltration water treatment systems from studies conducted around the world. The authors collectively represent a perspective from 23 countries and include academics/researchers, biofiltration system users, designers, and manufacturers. Progress in Slow Sand and Alternative Biofiltration Processes !! Further Developments and Applications offers technical information and discussion to provide perspective on the biological and physical factors affecting the performance of slow sand filtration and biological filtration processes. Chapters have been submitted from the 5th International Slow Sand and Alternative Biological Filtration Conference, Nagoya, Japan in June 2014. ISBN: 9781780406381 (eBook) ISBN: 9781780406374 (Print)

Study on the Treatment of Surfactant Wastewater by Anaerobic Biological Filter

Through experimental study on industrial wastewater of NanFengRiHua by Anaerobic Biological Filter process (AF), AF was proved as an efficient treatment process for refractory industry wastewater. AF process can change molecular structure and improve the biodegradability of nonbiodegradable organic, so AF process has very good practical prospects

Biological treatment options for cyanobacteria metabolite removal – A review

The treatment of cyanobacterial metabolites can consume many resources for water authorities which can be problematic especially with the recent shift away from chemical- and energy-intensive processes towards carbon and climate neutrality. In recent times, there has been a renaissance in biological treatment, in particular, biological filtration processes, for cyanobacteria metabolite removal. This in part, is due to the advances in molecular microbiology which has assisted in further understanding the biodegradation processes of specific cyanobacteria metabolites. However, there is currently no concise portfolio which captures all the pertinent information for the biological treatment of a range of cyanobacterial metabolites. This review encapsulates all the relevant information to date in one document and provides insights into how biological treatment options can be implemented in treatment plants for optimum cyanobacterial metabolite removal.

The effect of air supply on nitrogen removal using a biological filter proposed for ventilated pit latrines

Pit latrines are the most commonly used sanitation systems in many developing countries. Various researchers have reported elevated nitrate concentrations in groundwater in the vicinity of pit latrines and this could pose a serious health risk to the users of the water source. Faecal sludge from pit latrines contains high concentrations of nitrogen and organicmatter (3-5 g·l-1 N and 20-50 g·l-1 COD); however, it is produced at a very low rate (1.5 l·capita-1·d-1) relative to that of waterborne sewage systems. A pit latrine basically only confines the waste and no real treatment takes place. In this research the nitrogen was removed in a biological filter using a combination of nitrification and denitrification processes. The aim of this investigation was to determine the effect of air supplied at different rates, namely, 0, 0.3, 1.0 and 2.0 m3·h-1 N, on the biological filtration process. The application rate was 0.04 m3·m-2·d-1. More than 90% removal of nitrogen was observed at an air supply rate of 1.0 m3·h-1 N. At lower air supply rates nitrification was not complete. At an air supply rate of 2.0 m3·h-1 nitrogen removal was also approx. 90%, but the biological filter only became stable after about 2 months of operation, possibly due to desiccation of the biomass.

Phosphorus Removed by High Calcium Fly Ash Ceramsite in Artificial Biological Filter Bed

Fly ash Ceramsite, Artificial Biofilter Bed, Dry Umbrella Bamboo, Phosphorus Removal Abstract: High calcium fly ash ceramsite had tremendous surface area and porosity, the unit weight of fly ash adsorption column adsorption capacity of ceramsite was 0.032mg•g-1, which was higher than normal calcium fly ash ceramsite adsorption capacity. The fix adsorption column tests showed that the adsorption capacity got stable when the contact time was 3 hours and the saturation adsorption was got at the ninth hour. The result of subsequent tests showed that the phosphorus resolve would not occur if the adsorption condition doesn’t change. The pilot test with actual wastewater was done and the results showed that the PO43- concentrations of effluent were less than 0.2mg•L-1 and the removal rate reached 90%, dry umbrella bamboo was the most suitable aquatic plant. The artificial biological filter process monitoring showed that the phosphorus of the sewage was mainly removed in the front of artificial biological filter bed.

Sewage Treatment of Post-Denitrification Oxic/Anoxic Biological Filter

The paper is intended to investigate the effect of denitrification and COD removal in the post-denitrification biological filter process, adding an external carbon source. Tow carbon sources are dosed, methanol and sewage. The experiment performs in a tow-classes biological filter, oxic zone and anoxic zone, indicate that denitrification rate can be instantaneously increased through the addition of either carbon source. The perfect inputs flow of methanol and sewage are 20 mg/L and 0.2Q (Q is the effluent flow). These results indicate that methanol is better than sewage to denitrification as carbon source and the effluent concentration of COD was low.

Development of biological filter as tertiary treatment for effective nitrogen removal: Biological filter for tertiary treatment

A biological filtration process applicable to tertiary treatment of sewage for effective nitrogen removal was developed. It consisted of a nitrification filter (Filter 1) and/or a polishing filter with anoxic and oxic parts (Filter 2). A pilot plant set at a municipal sewage treatment plant was operated for 525 d with feed of real sewage. The maximum apparent nitrification rate in Filter 1 in winter was 0.54 kgN/m 3- filter-bed d. In Filter 2, the maximum denitrification capacity was 4 kgN/m 3 filter-bed d) in winter. SS was stably removed and high transparency water was obtained. The target water quality (SS, BOD, and T-N⩽5 mg/L) was accomplished in winter with the LV of 202 m/d in Filter 2, which corresponds to 0.24 h of HRT. These results proved that this process is compact, stable, convenient to install, and cost effective to build and operate as tertiary treatment to remove nitrogen effectively.

Three Stage Biological Filter Process to Achieve Extremely Low Total Nitrogen Discharge to the Long Island Sound

Three Stage Biological Filter Process to Achieve Extremely Low Total Nitrogen Discharge to the Long Island Sound

AOC removal and accumulation of bacteria in experimental sand filters

Using small sand filets under well defined laboratory conditions, filtration experiments were performed with tap water supplemented with acetate. The objective of these experiments was to determine the effect of different acetate concentrations on (i) the removal of easily assimilable organic carbon (AOC) in the filter (ii), the clogging of the tiller and (iii) the bacteriological quality of the filtrate. The results of the experiments revealed that the reduction capacity of biological filtration processes for acetate is relatively high. Acetate removal resulted in an increased microbiological activity in the top layer (< 1cm) of the filter bed and accumulation of bacterial matter was observed at an influent AOC concentration as low as 0.005 mg of ac-C eq/l. Clogging of the filter bed occurred at an influent acetate concentration of 0.01 mg C/l. Based on these observations it was concluded that the AOC concentration of water used for infiltration in recharge wells should be less thon 0.01 mg ac-C eq/l. This level is similar to the level advised for biologically-stable drinking water. A linear relationship was found between the acetate removal in the experimental filters and the colony count in the filtrate. It was recommended that the AOC load in the final filtration process in water treatment therefore should be limited to prevent high colony counts in the filtrate, thus leading to the use of post disinfection.

Development of a biological filtration model applied for advanced treatment of sewage

A mathematical model of biological filtration process is developed in this paper. A biological filtration process has advantages that filtration action and biological activities are combined in a single reactor with aid of filter media. Both physical and biological functions are incorporated in this developed model to simulate both mechanisms. Backwashing is expressed by the assumption that a mean captured solids concentration is input as data, and a captured solids concentration is kept at that value during each filtration run. The developed model is applied to explain the experimental performance with biological filtration reactors, in which batch cultivation of autotrophic bacteria and continuous treatment of actual sewage are carried out. Its applicability is discussed by comparing the simulated results with the experimental data. This model can favourably estimate maximum accumulation of autotrophic bacteria on the medium in batch cultivation, long-term treatment performance in continuous treatment, details of water quality profiles through the filter bed, and biomass. Required hydraulic retention time for nitrification and an appropriate recirculation ratio in a winter season are discussed with this model. This model predicts that a HRT of 1.1 h or above is required to achieve nitrification with remaining NH 4 +-N of less than 1 mgN/L and that an appropriate recirculation ratio is 2–3.

Advanced treatment of sewage by pre-coagulation and biological filtration process

A pre-coagulation and bio-filtration process for advanced treatment of sewage was developed and experimentally discussed with a pilot plant. The bio-filtration unit consists of a denitrification filter, a nitrification filter with side stream to the denitrification filter, and a polishing filter with anoxic and aerobic parts. Concentrations of SS, T-COD Cr, T-carbonaceous BOD, T-N and T-P in the effluent were stably kept at less than 3, 20, 5 mg/L, 2 mg N/L and 0.2 mg P/L, respectively, and transparency at higher than 100 cm, under total hydraulic retention time of 3.2 h in the bio-filtration parts (filter-bed). ORP in an anoxic tank before a nitrification tank should be at a low level of less than −120 mV to keep remaining NO x −–N less than 1 mg N/L, but must be maintained at a level higher than −150 mV. The maximum nitrogen-loading rate under a water temperature of 18°C should be less than 0.25 kg N/(m 3-filter-bed·d). Concentrations of microorganisms kept in the reactors were as high as 4000–5000 mg COD/L-filter-bed. Denitrification activity of 0.4 or 0.7 kg N/(m 3-filter-bed·d), and nitrification activity of 0.3 kg N/(m 3-filter-bed·d) were obtained, respectively, under a water temperature of about 18°C. Backwashing in each tank as well as methanol addition and aeration in the polishing filter were operated successfully by the automatic control systems. These results proved that this process is applicable to advanced treatment of sewage with easy maintenance.

Improvement of Nitrogen Removal Efficiency of an Anaerobic Filter-Aerobic Biological Filtration Process by Using Nitrifying Bacteria Immobilized Pellets

In order to improve nitrogen removal efficiency, an anaerobic filter-aerobic biological filtration process was modified by filling. with nitrifying bacteria immobilized carrier made of polyethylene-alcohol (immobilized pellets) as a media for biological filtration tank. The effect of water temperature on T-N removal efficiency was investigated.When aeration was performed so that the immobilized pellets were fluidized above the ceramic carrier filled in the biological filtration tank, T-N was successfully removed. T-N removal efficiency was increased by increasing the filled ratio of immobilized pellets by replacing a portion of the ceramic carrier at the water temperature of 10°C. Conversely, the removal efficiency was lower when the filled ratio of immobilized pellets was 60%, due to the increase of suspended solids in the effluent. Therefore, a proper filled ratio of immobilized pellets was thought to be about 50%.The nitrification rate at the water temperature of 5°C was 17 mg·l-1·h-1 for the immobilized pellets and 3.9 mg·l-1·h-1 for the ceramic carrier, thus the nitrification rate of the former was 4.4 times that of the latter. Removal rates of the inflow carbon and nitrogen were 72% as carbon dioxide and 65% as nitrogen gas, respectively.

Removal of Humic Substances by Oxidation/Biofiltration Processes - a Review

The paper is concerned principally with summarising the experience to-date of treating low alkalinity, low turbidity, humic-rich surface waters by the combination of ozone oxidation and biological filtration processes. In the UK, USA and other countries, upland coloured waters have often been treated by slow sand filtration in which only moderate removals of DOC have been achieved (< 20%). The presence of significant levels of humic matter in filtrate waters has led to difficulties in achieving compliance with the standards for colour and THMs, and concern about the stability of residual chlorine and potential biogrowth in water supply pipework. This has led to several investigations (eg. in the UK, Sweden and the USA) of the benefits of applying ozonation prior to slow sand filtration in view of its known capability to decolorise humic substances and enhance biodegradability of the organic fractions. This paper summarises the experience to-date and highlights the benefits and problems that have been identified. Some studies have attempted to compare the relative performances of slow sand filters and granular activated carbon (GAC) filters for the removal of BDOC and the paper reviews the principal findings of these studies in view of the growing worldwide interest in the application of ozone-GAC. One major limitation with the use of ozone-GAC is the need periodically to remove and regenerate the carbon, since bed lives for the removal of humic substances are typically short. An alternative approach is to use inorganic adsorbents instead of carbon which have the potential to be chemically regenerated in-situ. The paper refers to the results of laboratory tests that have been carried out on the potential use of pre-ozonation followed by inorganic adsorbents (eg. Activated alumina, bauxite) for the removal of humic substances.

Removal of humic substances by oxidation/biofiltration processes — A review

The paper is concerned principally with summarising the experience to-date of treating low alkalinity, low turbidity, humic-rich surface waters by the combination of ozone oxidation and biological filtration processes. In the UK, USA and other countries, upland coloured waters have often been treated by slow sand filtration in which only moderate removals of DOC have been achieved ( in-situ . The paper refers to the results of laboratory tests that have been carried out on the potential use of pre-ozonation followed by inorganic adsorbents (eg. Activated alumina, bauxite) for the removal of humic substances.

生物ろ過による池水浄化に関する実験的検討

Two laboratory-scale biological filter treatment systems packed with ceramics media and plastic media and control system withuot biological filter process were operated to treat polluted pond water. Three algal culture tanks with sufficient nutrient and light for growth were used as polluted ponds. A portion of water from the algal culture tank was withdrawn and treated through the biological filter process. The effluent was recirculated into the algal culture tank. Treatment performance of biological filter system was compared based on water quality of three algal culture tanks. The range of circulation ratio (feeding rate to biological filter process divided by the volume of the algal culture tank) was varied from 1.5 d-1 to 0.1 d-1. Growth of algae was depressed and sedimentation rates of suspended solids increased in the tank with biological filter process even if the circulation ratio was low (i.e., 0.1 d-1). There was no difference between water quality and algal composition in the two tanks with two different packing media. The biological filter process could increase the transparency of polluted pond water and the diversity of algal species compared to the control tank.

Simultaneous Removal of Nitrogen and THM Precursor by Developed Submerged Biofilm Process for Drinking Water

Reciprocating motion submerged biofilm process(RMSBP) was developed for nitrogen, biodegradable carbon and trihalomethane (THM) precursor simultaneous removal as a pre-treatment of polluted raw water for drinking water supply. The focus of this study is to get a stable treatment water through four seasons under no pre-sedimentation systems. All experiments were done at the lake side, and raw water was introduced from the lake continually. There is no sedimentation tank in the reactors and biofilm carrier clogging dose not occur and biofilm growth is uniform through the whole reactors by reciprocating motion carrier. RMSBP was able to decrease NH4−N, and NO2−N and NO3−N simultaneously under unaerated conditions. Decrease of nonpurgeable DOC and ultraviolet(UV) absorbance (1 cm path length, pH7.0, 260nm) is possible almost two toten times more expensive than the traditional biological filtration process. Nitrification, denitrification, biodegradable carbon and THM precursor removal was stably achieved simultaneously from autumn to spring when water temperature is low