Biological Treatment Methods Research Articles

UASB performance in presence of algae and synthetic media

An upflow anaerobic sludge blanket (UASB) technology has showed an excellent performance compared to other biological treatment methods when a high organic loading rate of domestic and industrial wastewaters was applied. The objective of this study was to investigate the effect algae from lake-sediments and synthetic activated ceramic as media on UASB performance. The algae and synthetic media were introduced to the UASB reactor in order to obtain the enhanced granulation, which resulted in the increase in the UASB performance. 1–3% higher methane content and 3–10% higher COD removal efficiency were obtained in the reactors with the media than in the reactor without the media. The respective gas production rates in reactors 1,2, and 3 were 0.15–0.36 m3/kg COD-day, 0.24–0.54 m3/kg COD-day, and 0.24–0.56 m3/kg COD-day. As organic loading rate increased, gas production rates increased.

5582732 Biological method of waste water treatment : Mao Huazhong; Lourenco Jose J Edmonton, Canada Assigned to Aquatex Corporation

5582732 Biological method of waste water treatment : Mao Huazhong; Lourenco Jose J Edmonton, Canada Assigned to Aquatex Corporation

5468392 Submerged fixed-film biological waste treatment method and system

A system for the collection and use of radiation data on airborne particulate materials, which system provides one or more facets of enhanced data accuracy, security, retrievability, accountability of personnel, chain of custody, or the like, the system having the following components: (a) an airborne material collection filter means having bar code indicia thereon; (b) a computer adapted for storing and/or processing record data and property data; (c) a bar code reader adapted for interfacing with the bar code on the filter means and accessing record data thereon, the reader also being adapted for interfacing with the computer for the transport of record data thereto; and (d) a radiation counter adapted for analyzing and providing radioactivity (property data) on particulate materials collected by the filter means and for interfacing with the computer for the transport of the property data thereto; (e) the computer being adapted for correlating the record data and property data and calculating and reporting work radiation exposure, and/or forwarding the same to storage or further data processing facilities.

Radiolytic Elimination of Organochlorine in Pulp Mill Effluent

Chlorinated organic compounds, formed during the bleaching of Kraft pulp with chlorine and chlorine dioxide bleaching agents, are commonly measured in pulp mill effluent as adsorbable organic halogen (AOX). Existing biological treatment methods can typically remove less than 50% of the AOX, which may not be adequate for compliance with future regulations. As a potential treatment method, the radiolytic elimination of organochlorine in pulp mill effluent was investigated in bench-scale experiments. Biotreated and untreated effluent as well as E-stage and C-stage filtrates from a pulp mill were irradiated in a cobalt-60 γ-cell. For treated, untreated, E-stage, and C-stage effluent more than 95%, 90%, 70%, and 60% AOX removal was obtained for doses up to 60 kGy, respectively. An increase in organochlorine removal was observed at high pH and in the absence of oxygen. In treated effluent, AOX removal increased from less than 70% in the aerated neutral solution to 80% in the basic media (pH = 12) and to 96% in the absence of oxygen for a dose of 10 kGy.

Biological Remediation of Polynuclear Aromatic Hydrocarbon Contaminated Soils UsingAcinetobactersp.

Soils contaminated with polynuclear aromatic hydrocarbons (PAHs) pose a hazard to life. The remediation of such sites has been attempted using various methods such as solvent washing, air stripping, incineration, composting, electrokinetic remediation, and supercritical extraction. However, applicability of these physical, chemical, and biological treatment methods or their combination is critically dependent on soil characteristics, nature and level of contamination, site specifications, and economic feasibility, to name a few. Present research is aimed at studying the applicability of biological treatment for decontamination of industrial soil containing PAHs. The current preliminary study included soil analysis, contaminant characterization, and soil treatment using Acinetobacter sp. The soil treatment over a 5-week period, with minimal supplemental nutrient addition, showed removal efficiencies of 80% and more. The effect of initial microbial population in soil on the removal efficiency over a 5-week ...

Engineering Model for Fixed-Film Bioscrubbers

The three basic types of biological treatment systems for the control of volatile organic compounds in air streams are the following: biofilters, in which microorganisms grow on a medium, such as soil, compost, peat, or mixtures of these materials with wood chips or polystyrene particles; suspended-growth bioscrubbers, in which microorganisms are suspended in a liquid; and fixed-film bioscrubbers, in which microorganisms are attached to a packing material. Design and application of biological treatment methods for air pollution control are difficult because only limited experimental data and few theoretical models are available. This paper utilizes an engineering simulation model of a fixed-film bioscrubber to investigate the applicability, removal efficiency, operational parameters, and design requirements for gaseous waste streams. Model results indicate that the removal efficiencies can be increased by increasing the column height, decreasing the superficial gas velocity or the superficial liquid veloc...

A Review of Hydraulics in Fluidized-bed Biological Filters

Fluidized sand-beds are efficient and cost-effective methods for biological treatment within recirculating aquaculture systems, and have recently been the topic of considerable research. However, their hydraulic design has been largely undescribed in the aquaculture literature, and at this point, hydraulic criteria are typically obtained from preliminary laboratory fluidization studies on media samples obtained from distributors. This article summarizes and applies techniques developed in other disciplines for calculating fluidization hydraulics, based solely upon characteristics of the granular medium, for the purpose of designing biological fluidized-bed units for use in recycle aquaculture. These calculations require knowledge of five characteristics: (1) and (2) the mediums size gradation and effective diameter, estimated from sieve analysis provided by the supplier, (3) the mediums density, obtained from a property of materials table, and (4) and (5) the mediums sphericity and the bed porosity, both of which can be reasonably assumed, particularly with sands. Solutions to fluidization calculations are presented as simplified curves useful for sensitivity analysis for optimizing unit design. This article also discusses the (1) characteristics which make a medium suitable for use in nitrifying fluidized beds in aquaculture, (2) design criteria for proper distribution of water at the bottom of the fluidized bed, and (3) special issues involving fluidization hydraulics and the application of fluidized beds to aquaculture.

A Novel Method for Biological Treatment of Bleached Kraft Mill Wastewaters

Removal of adsorbable organic halogen (AOX) and chemical oxygen demand (COD) from bleached kraft mill effluent was investigated in laboratory and pilot scale aerobic suspended carrier reactors and abiotic thermo-alkaline reactors. Laboratory treatment focused on determination of loading capacity of the suspended carrier process and operation of the process at elevated temperature and pH values in order to combine abiotic thermo-alkaline dechlorination and biological treatment in one reactor. At pH 7, 37°C and hydraulic retention times (HRTs) longer than 3.5 hours, a maximum COD removal of 55% was achieved in the suspended carrier process. The COD conversion rate at the minimum HRT was 2.6 kg COD/(m3*d). The suspended carrier treatment was operated successfully at pH 9.0 and 45°C and at pH 7.0 and 50°C with over 50 percent COD removal with a HRT of four hours. The AOX removal achieved at pH 9 and 45°C (50%) was significantly higher than the removal at pH 7 and 37°C (39%), most certainly because of an increased abiotic dechlorination at the higher pH and temperature levels. Sequential thermo-alkaline and biological treatment were studied on a pilot scale. Tbermo-alkaline treatment at pH 10, 54°C and a HRT of two hours followed by biological treatment at pH 8, 35°C and a HRT of four hours, removed almost 80% of AOX and 50% of COD from the kraft mill effluent.

International conference on contemporary methods of biological treatment of mental disorders

International conference on contemporary methods of biological treatment of mental disorders

Modification of chemical characteristics of organically enriched sediment by Capitella sp. I

The influence of biological activities of a deposit feeding polychaete, Capitella sp. I to the chemical characteristics of the organically enriched sediment was examined in the laboratory experiments. The laboratory colonies of Capitella increased very rapidly in the organically enriched sediment of the culturing boxes. In the process of the rapid population growth, the biological activities of the worms apparently promoted the decomposition of organic matter in the sediment, and decreased the levels of acid volatile sulphide (AVS) in the sediment. The results of the present study indicate that the effect of Capitella imposed on the sediment may be a method of biological treatment of the organically polluted sediment.

活性汚泥混合液中でのウイルス感染価の低減について

Recently reported virus contamination in natural waters is considered to be closely dependent upon insufficient virus removal in the sewage treatment process. Therefore, it is necessary to clarify the behavior of viruses in the treatment process.This research was undertaken to elucidate the factors effecting virus behavior in an aeration tank in the activated sludge process. This process is at present the most popular biological sewage treatment method. The effects of MLSS concentration, temperature and pH on virus reduction were investigated in batch experiments using a vaccine strain of attenuated poliovirus type 1 (LSc, 2ab) as a model virus. The infectivity of virus was determined by the plaque assay using BGM cells.The results indicated that the virus infectivity in a mixed liquor of activated sludge decreased exponentially with time. Regardless of MLSS concentration, temperature and pH, the time course of virus infectivity reduction could be expressed as two consecutive stages. The first stage decreased more rapidly than the second one while both were characterized by first-order kinetics. The reduction of virus infectivity was found to be proportional to MLSS concentration and effective for the condition of low pH and high temperature in the aeration tank.

Effect of Shear Stress on Granulation in Oxygen Aerobic Upflow Sludge Bed Reactors

Aerobic upflow sludge blanket(AUSB) process is a new biological wastewater treatment method applying the concept of the self-immobilization to activated sludge. Two sets of AUSB system with different mixing velocities of 3 rpm(R1) and 6 rpm(R2) were operated for high-rate treatment of synthetic wastewater. The COD removal efficiency in R2 was higher than R1 at the same loading rate up to 7 kg/m3·day. However, in R1, the sludge bulking was observed at the end of the experiment. The chocolate colored granules were formed about 5 days after the start-up. The morphological study on the granular sludge consortia was made with both scanning electron and optical microscopes. The granules were 0.5-2.5 mm in diameter and mainly consisted of bacteria with pili-like appendages and filamentous bacteria, which were thought to be Sphaerotilus natans and Beggiatoa. In R1, the long multicellular filaments causing bulking were prevalent in the granule, while in R2 overgrowth of filamentous bacteria was prevented with appropriate shear stress resulting in higher MLSS density. Experimental results indicated that granulation could be controlled by physical stress on granular sludge.

Mechanisms of bacterial degradation and transformation of chlorinated monoaromatic compounds

Chloroaromatics are xenobiotic compounds of environmental concern. They can be removed from the environment by (bio)degradation or by (bio)transformation. Recognition of the mechanisms and requirements of their biodegradation is of cardinal importance for understanding the fate of these chemicals in the environment, and for developing methods for biological treatment of wastes containing compounds of this type. Cleavage of the carbon-halogen bond is the critical step in degradation of chloroaromatics. As exemplified with chlorophenols, chlorobenzoates and chlorobenzenes in this review, two distinct strategies are employed by bacteria for degradation of chlorinated aromatic compounds: the particular chlorine substituents are removed either directly from the aromatic ring (as an initial step in degradation) or after oxygenative ring cleavage (from chlorinated aliphatic intermediates). Direct elimination of chlorine substituents from the aromatic ring occurs by displacement with either hydroxyl groups (hydrolytically or oxygenolytically) or hydrogen atoms (reductive dechlorination). Dechlorinations of the latter type require reducing power and are significant in anaerobic environments, but have also been observed with strictly aerobic bacteria. Various biotransformation reactions, with only minor alteration of the parent compound, are an alternative to biogradation. Two environmentally significant transformation reactions discussed here are O-methylation and O-demethylation. The capability to O-methylate chlorinated hydroxybenzenes seems to be widespread in bacteria. O-Methylation is an environmentally important transformation reaction, since methylation increases the lipophilicity of the compound and thus the potential for bioaccumulation. Bacterial O-demethylation of chlorinated methoxylated compounds has been observed under both aerobic and anaerobic conditions.

Selection of the Most Appropriate Leachate Treatment Methods: Part 1: A Review of Potential Biological Leachate Treatment Methods

Abstract This paper presents a review of North American and European literature concerning the physical and chemical characteristics of leachate and the biological treatment methods that have been used or could be used to treat leachate. Leachate characteristics of particular interest include five-day biochemical oxygen demand (BOD5) , chemical oxygen demand (COD), the BOD5/COD ratio, molecular weight and or size of the organics, volatile fatty acids (VFA’s), ammonia and metals. It is demonstrated that biological leachate treatment is most appropriate when the BOD5/COD ratio is high (i.e. > 0.4) and the molecular weight of the majority of the organics is less than 500 g/mole. Tables summarizing the various biological leachate treatment process loading rates are presented. This paper serves as the basis for two companion papers: ”Selection of the Most Appropriate Leachate Treatment Methods, PART 2 : A Review of Recirculation, Irrigation and Potential Physical-Chemical Treatment Methods” and “Selection of the Most Appropriate Leachate Treatment Methods, PART 3: A Decision Model for Treatment Train Selection”.

On the Utilization of Biological Methods in Groundwater Treatment

Biological water treatment has been used for more than a century. The processes involved, however, have not been optimally utilized, since knowledge about their character and significance has been insufficient. As conventional water purification techniques developed, the use of biological processes remained in the background until a few decades ago. However, at the moment several biological treatment methods are in use to remove iron and manganese from groundwater, and the future looks promising. The same methods can be used to improve numerous other water quality parameters, e.g. to oxidize reduced nitrogen compounds into nitrates. Biological removal of nitrate, too, will be a future water treatment method.

Process Alternatives for Enhanced Biological Treatment Efficiency of Forest Industry Effluents

Biological wastewater treatment methods are being used at an ever increasing extent for the treatment of wastewaters from the Finnish forest industry. Conventional activated sludge processes treating the composite wastewaters from the mill are most commonly used. Present plants may turn out to be inadequate in some cases, or they may not serve the purpose. This can happen for example when 1) the process fails or the running costs become extremely high, 2) the legal regulations concerning the quality of the treated wastewater change or 3) production of the mill expands or is diversified. These situations can be handled by expanding the existing treatment capacity. An alternative is to develop specific additional treatment units more appropriate for the wastewaters in question. In this paper the advantages and disadvantages of some biological process units completing activated sludge treatment plants are studied. In experimental studies a, b and c, a two-stage activated sludge process, a modified activated sludge process and an anaerobic pretreatment, respectively, are examined. The results of these studies show that a selective, highly loaded first stage of a two-stage activated sludge process can efficiently equalize and improve effluent quality, especially when the suspended solids concentration in the influent is high (Study a), that an anoxic/anaerobic unit together with a small aerated contact unit combined with a conventional activated sludge process can reduce phosphorus levels in the effluent (Study b), and that anaerobic pretreatment of concentrated wastewaters efficiently reduces the organic loading, improves sludge settling properties, and reduces sludge yield and phosphorus demand (Study c).

4662900 Method for biological treatment of waste gases: Simon P P Ottengraf, Stiphout, Netherlands assigned to Clair Tech B V

4662900 Method for biological treatment of waste gases: Simon P P Ottengraf, Stiphout, Netherlands assigned to Clair Tech B V

4662900 Method for biological treatment of waste gases

4662900 Method for biological treatment of waste gases

Recent Findings in Adolescent Depression and Suicide

Adolescent depression and suicide are currently the focus of lively investigation. While diagnostic terminology and prevalence of depression remain unresolved, promising clarification is likely from the new assessment techniques readily available. These range from vigorous history taking and the use of questionnaires to biological tests. Associated depressive spectrum conditions are being defined. Like depression itself, they often respond to the new biological and psychological treatment methods of demonstrated effectiveness. Compounds are under development which may lessen side effects, and plasma antidepressant measurements are of proven value. Even with respect to adolescent suicidal behavior, where similar biological and psychological approaches have yielded less impressive results to date, energetic diagnosis and intervention can be lifesaving.

Apparatus and a method for biological treatment of waste waters : Ferdinan Besik, Mississauga, Ontario, Canada

Apparatus and a method for biological treatment of waste waters : Ferdinan Besik, Mississauga, Ontario, Canada