scholarly journals Odours in Sewerage—A Description of Emissions and of Technical Abatement Measures

Environments ◽  
2019 ◽  
Vol 6 (8) ◽  
pp. 89 ◽  
Author(s):  
Pochwat ◽  
Kida ◽  
Ziembowicz ◽  
Koszelnik
Keyword(s):  
Chemical Nature ◽  
Sewage Treatment ◽  
Complex Mixture ◽  
Green Technology ◽  
Process Conditions ◽  
Wastewater Management ◽  
Legal Regulations ◽  
Anaerobic Conditions ◽  
Eu Member States ◽  
Odour Annoyance

Malodorous compounds arise at practically every stage of wastewater management, starting from the sewer network, via the technological sewage-treatment system, through to the sludge-management stage. The formation of hydrogen sulphide is a significant problem even while sewage remains in sewers, as anaerobic conditions prevalent in the network are conducive to wastewater putrefaction, and therefore contribute to increased malodorous emissions. The development of such anaerobic conditions is favoured by the oversizing of conduits or designs that feature inadequate gradients, causing wastewater in the network to stagnate. Where emissions to the air from wastewater occur, they are found to constitute a complex mixture of perhaps even 1000 different substances, produced under varying process conditions. Among those present are compounds of sulphur and nitrogen, chlorinated compounds, and other organics. In Poland, the issue of odour annoyance has not yet been subject to standardisation in either legal or methodological terms. Indeed, as only 11 EU Member States have regulations in place regarding air-quality standards, it is likely that such a law will soon be developed to try and resolve problems with odour annoyance, including those originating in the systems dealing with wastewater. This denotes a need to develop methods of counteracting the formation of odours, and those of a chemical nature are regarded as among the most effective, hence their growing popularity. They also abide by green-technology principles. Against that background, this article seeks to consider the process by which malodorous substances arise in sewer and wastewater-treatment systems, as well as to discuss methods of odour abatement. The work also presents the current legal regulations of relevance to the issue.

Sewage Treatment by Waste Stabilization Pond Systems

2018 ◽  
Vol 3 (1) ◽  
pp. 7-14
Author(s):  
J. Kenneth, R. S. Suglo
Keyword(s):  
Management Practices ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Wastewater Management ◽  
Stabilization Pond ◽  
Waste Stabilization Pond ◽  
Quality Guidelines ◽  
Waste Stabilization ◽  
High Reduction ◽  
Wastewater Samples

Sewage generated in Ghana is commonly discharged into the environment without any form of treatment to reduce the degree ofcontamination and mitigate potential public health and environmental issues. Although some attempts have been made in someparts of Ghana to utilize the waste stabilization pond (WSP) system to treat domestic sewage, the ponds often fail to achievetheir purpose due to lack of basic maintenance and supervision. To assess the utility of the WSP system for treating sewage,wastewater samples were collected from the raw sewage, anaerobic, facultative and maturation ponds of WSPs at Obuasi inGhana, and analyzed for physicochemical and microbiological contaminants. The results show that the final pond effluent meetsrecommended microbiological and chemical quality guidelines. The waste stabilization pond system demonstrates high removalefficiencies of wastewater contaminants. The biochemical oxygen demand, total suspended solids, nitrate and faecal coliformsreduction efficiencies of 97.3%, 97.6%, 83.3% and 99.94% respectively are highly significant, and compare well with reportedremoval efficiencies in the literature. Additionally, the ponds have high reduction efficiencies for heavy metals and pathogenicmicroorganisms. The wastewater treatment system complies with standard wastewater management practices, and provides auseful method for treating and disposing wastewater in Ghana.

Multi-species plant systems for wastewater quality improvements and habitat enhancement

1996 ◽  
Vol 33 (10-11) ◽  
pp. 231-236 ◽  
Author(s):  
Martin M. Karpiscak ◽  
Charles P. Gerba ◽  
Pamela M. Watt ◽  
Kennith E. Foster ◽  
Jeanne A. Falabi
Keyword(s):  
Municipal Wastewater ◽  
Sewage Treatment ◽  
Giant Reed ◽  
Coliform Bacteria ◽  
Wastewater Management ◽  
Joint Project ◽  
Pima County ◽  
Wastewater Quality ◽  
Habitat Enhancement ◽  
Constructed Ecosystems

The use of macrophytic plants for the treatment of municipal wastewater is growing rapidly. The Constructed Ecosystems Research Facility (CERF) is a joint project of the Pima County Wastewater Management Department and The University of Arizona's Office of Arid Lands Studies. The facility consists of five 30-mil-hyperlon-lined raceways measuring 61 m long, 8.2 m wide, and 1.4 m deep and one slightly larger raceway. Research has been and is being conducted with aquatic plants such as water hyacinth (Eichhornia crassipes), duckweed (Lemna spp.), giant reed (Arundo donax), bulrush (Scirpus olneyi), black willow (Salix nigra), and cottonwood (Populus fremontii). Composite water samplers are used to collect refrigerated samples from incoming secondary wastewater from Pima County's Sewage Treatment Facility and from the effluent leaving each raceway. Water samples have been analyzed for parameters such as pH, BOD5, and total nitrogen. Microbiological studies have concentrated on the removal of indicator coliform bacteria, as well as Giardia, Cryptosporidium and viruses from the wastewater. Data from the water quality studies indicate that these constructed ecosystems reduce BOD5 consistently to below the 10 mg/L BOD5 tertiary standard, remove nitrogen as well as decrease the concentration of pathogens significantly.

The oxidation of hexane in the cool-flame region

1952 ◽  
Vol 212 (1110) ◽  
pp. 311-330 ◽  
Keyword(s):  
Atmospheric Pressure ◽  
Chemical Nature ◽  
Complex Mixture ◽  
Cyclic Ethers ◽  
Reaction Products ◽  
Cool Flame ◽  
Oxidation Of Methane ◽  
Cool Flames ◽  
Flame Region ◽  
Considerable Support

The chemical nature of the cool flame of hexane at 300°C, maintained stationary in a flow system at atmospheric pressure, has been investigated. The relative intensities of cool flames obtained from mixtures of differing composition have been measured, using a photomultiplier cell, and correlated with analyses made of the complex mixture of reaction products. The stationary two-stage flames which may be obtained at either higher oxygen concentrations or higher pressures than the cool flame are also described, and investigated similarly. The results are examined in the light of a theory of combustion of the higher hydrocarbons via aldehydes and hydroxyl radicals, which is an extension of a mechanism derived for the oxidation of methane. This receives considerable support, particularly from the identification of the complete homologous series of saturated aldehydes which can result from the hexane molecule. Associated with these reactions are others due to the greater stability of peroxide radicals at 300°C than at the higher temperatures of methane oxidation. Thus the building up of a partial pressure of hydroperoxide sufficient to ignite in the presence of oxygen may initiate the cool flame, and considerable amounts of cyclic ethers have been found which probably had a peroxidic precursor.

scholarly journals Decolorization, Biodegradation and Detoxification of Reactive Blue Azo Dye Using Immobilized Mixed Cells

2019 ◽  
Vol 25 (6) ◽  
pp. 53-66 ◽  
Author(s):  
Basma Basim Hameed ◽  
Zainab Ziad Ismail
Keyword(s):  
Azo Dye ◽  
Immobilized Cells ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Water Soluble ◽  
Phase Estimation ◽  
Bacterial Cells ◽  
Anaerobic Conditions ◽  
Batch Mode

Drastic threat to the natural system is caused by the uncontrolled release of synthetic pollutants, including azo dyes. This study centered on the decolorization and biodegradation of water soluble azo dye reactive blue (RB) in a batch mode sequential anaerobic-aerobic processes. A local sewage treatment plant was the source where activated sludge was collected to be used as non-adapted mixed culture with both free and the alginate immobilized cells for RB biodegradation. Under anaerobic conditions, the free and immobilized mixed cells were proved to completely decolorize 10 mg/ L of RB within 20 and 30 h, respectively. Alginate- immobilized mixed cells, resulted in 88%, 87%, and 87% maximum COD removals with samples containing RB at initial concentration of 10, 20, and 40 mg/L, respectively.  UV-vis spectra showed the biological cleavage of the azo bond in the anaerobic phase. Estimation of the phytotoxicity of the degraded metabolites suggested that the non-adapted immobilized mixed bacterial cells successfully detoxified RB azo dye.  

scholarly journals Identification of Biogenic Sulphate Corrosion of Concrete in Sewage Treatment Plant Settling Tank Walls

2020 ◽  
Vol 30 (3) ◽  
pp. 253-264
Author(s):  
Łukasz Krysiak ◽  
Paweł Falaciński ◽  
Łukasz Szarek
Keyword(s):  
Sulphuric Acid ◽  
Municipal Wastewater ◽  
Sewage Treatment ◽  
Settling Tank ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Cement Matrix ◽  
Wastewater Management ◽  
Municipal Wastewater Treatment ◽  
Biochemical Processes

Abstract One of the basic threats in terms of concrete used for tanks or ducts applied in wastewater management is the phenomenon of biogenic sulphate corrosion (BSC). BSC is a particular case of corrosion caused by the action of sulphuric acid (IV), which is formed as a result of a number of biochemical processes, which can take place, e.g. in an environment encountered within the aforementioned structures. Ions present in sulphuric acid react with cement hydration products, which leads to replacing the primary cement matrix components with compounds easily-soluble or highly-swelling during crystallization. The outcome of advanced corrosion is usually an observed formation of a white, amorphous, sponge-like mass, which is easily separated from the underlying concrete. The article discusses a case study of a BSC process in a newly constructed primary settling tank in a municipal wastewater treatment plant.

scholarly journals Fenton-type chemistry by a copper enzyme: molecular mechanism of polysaccharide oxidative cleavage

2016 ◽  
Author(s):  
Bastien Bissaro ◽  
Asmund K Rohr ◽  
Morten Skaugen ◽  
Zarah Forsberg ◽  
Svein J Horn ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Reaction Kinetics ◽  
Mode Of Action ◽  
Process Conditions ◽  
Enzyme Assays ◽  
Enzymatic Conversion ◽  
Redox Enzymes ◽  
Anaerobic Conditions ◽  
Lytic Polysaccharide Monooxygenases ◽  
Polysaccharide Monooxygenases

The discovery of Lytic Polysaccharide Monooxygenases (LPMOs) has been instrumental for the development of economically sustainable lignocellulose biorefineries. Despite the obvious importance of these exceptionally powerful redox enzymes, their mode of action remains enigmatic and their activity and stability under process conditions are hard to control. By using enzyme assays, mass spectrometry and experiments with labeled oxygen atoms, we show that H2O2, and not O2 as previously thought, is the co-substrate of LPMOs. By controlling H2O2 supply, stable reaction kinetics and high enzymatic rates are achieved, the LPMOs work under anaerobic conditions, and the need for adding stoichiometric amounts of reductants is alleviated. These results offer completely new perspectives regarding the mode of action of these unique mono-copper enzymes, the enzymatic conversion of biomass in Nature, and industrial biorefining.

scholarly journals Different Pyrolysis Process Conditions of South Asian Waste Coconut Shell and Characterization of Gas, Bio-Char, and Bio-Oil

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1970 ◽  
Author(s):  
Jayanto Kumar Sarkar ◽  
Qingyue Wang
Keyword(s):  
Pyrolysis Temperature ◽  
Fixed Bed ◽  
Complex Mixture ◽  
Product Yield ◽  
Vital Role ◽  
Fixed Bed Reactor ◽  
Coconut Shell ◽  
Process Conditions ◽  
Bio Oil ◽  
The Impact

In the present study, a series of laboratory experiments were conducted to examine the impact of pyrolysis temperature on the outcome yields of waste coconut shells in a fixed bed reactor under varying conditions of pyrolysis temperature, from 400 to 800 °C. The temperature was increased at a stable heating rate of about 10 °C/min, while keeping the sweeping gas (Ar) flow rate constant at about 100 mL/min. The bio-oil was described by Fourier transform infrared spectroscopy (FTIR) investigations and demonstrated to be an exceptionally oxygenated complex mixture. The resulting bio-chars were characterized by elemental analysis and scanning electron microscopy (SEM). The output of bio-char was diminished pointedly, from 33.6% to 28.6%, when the pyrolysis temperature ranged from 400 to 600 °C, respectively. In addition, the bio-chars were carbonized with the expansion of the pyrolysis temperature. Moreover, the remaining bio-char carbons were improved under a stable structure. Experimental results showed that the highest bio-oil yield was acquired at 600 °C, at about 48.7%. The production of gas increased from 15.4 to 18.3 wt.% as the temperature increased from 400 to 800 °C. Additionally, it was observed that temperature played a vital role on the product yield, as well as having a vital effect on the characteristics of waste coconut shell slow-pyrolysis.

Integrated odour modelling for sewage treatment works

2004 ◽  
Vol 50 (4) ◽  
pp. 169-176 ◽  
Author(s):  
P. Gostelow ◽  
S.A. Parsons ◽  
M. Lovell
Keyword(s):  
Liquid Phase ◽  
Sewage Treatment ◽  
Emission Rates ◽  
Dispersion Models ◽  
Odour Source ◽  
Treatment Processes ◽  
Flow Quality ◽  
Odour Annoyance ◽  
Further Development

Odours from sewage treatment works are a significant source of environmental annoyance. There is a need for tools to assess the degree of annoyance caused, and to assess strategies for mitigation of the problem. This is the role of odour modelling. Four main stages are important in the development of an odour problem. Firstly, the odorous molecules must be formed in the liquid phase. They must then transfer from the liquid to the gaseous phase. They are then transported through the atmosphere to the population surrounding the odour source, and are then perceived and assessed by that population. Odour modelling as currently practised tends to concentrate on the transportation of odorants through the atmosphere, with the other areas receiving less attention. Instead, odour modelling should consider each stage in an integrated manner. This paper describes the development of integrated odour models for annoyance prediction. The models describe the liquid-phase transformations and emission of hydrogen sulphide from sewage treatment processes. Model output is in a form suitable for integration with dispersion models, the predictions of which can in turn be used to indicate the probability of annoyance. The models have been applied to both hypothetical and real sewage treatment works cases. Simulation results have highlighted the potential variability of emission rates from sewage treatment works, resulting from flow, quality and meteorological variations. Emission rate variations can have significant effects on annoyance predictions, which is an important finding, as they are usually considered to be fixed and only meteorological variations are considered in predicting the odour footprint. Areas for further development of integrated odour modelling are discussed, in particular the search for improved links between analytical and sensory measurements, and a better understanding of dose/response relationships for odour annoyance.

INTEGRATED SEDIMENTOLOGICAL ANALYSIS: THE EOCENE OF THE BASS BASIN

1989 ◽  
Vol 29 (1) ◽  
pp. 312
Author(s):  
Peter W. Baillie ◽  
Carol A. Bacon
Keyword(s):  
Sea Level ◽  
Sequence Stratigraphy ◽  
Complex Mixture ◽  
Sediment Supply ◽  
Log Analysis ◽  
Core Analysis ◽  
Anaerobic Conditions ◽  
Complex Interplay ◽  
Maximum Thickness ◽  
Sand Bars

The Eocene section in the Bass Basin comprises the upper part of the siliciclastic coal- bearing Eastern View Group and the thin but regionally extensive Demons Bluff Formation.An integrated sedimentological study utilising core analysis, log analysis, palynology, coal maceral studies and geochemistry, together with sequence stratigraphy, has been used to determine Eocene sedimentation styles in the basin.The most likely environment during deposition of the Upper Eastern View Group was a tide- dominated delta consisting of a complex mixture of distributary channels, strandline sand bars, peat swamps and shallow lagoons, the sedimentary successions resulting from a complex interplay between sea- level, tectonics and sediment supply. A major coal- forming episode occurring in the interval 48- 51.5 m.y. is related to oscillations of sea- level following a major highstand.A locally developed progradational unit, Konkon Sandstone, comprising two sandy parasequences separated by a very thin shaly interval is recognised at the top of the Eastern View Group in the northwestern sector of the basin and reaches a maximum thickness of 140 m.The Demons Bluff Formation is a diachronous unit consisting dominantly of siltstone probably deposited in a barred basin with anaerobic conditions.

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