58 research outputs found
Filament identification and dominance of Eikelboom Type 0092 in activated sludge from wastewater treatment facilities in Cape Town, South Africa
Routine characterisation of activated sludge and identification of the filamentous population by microscopic and/or other non-culture dependent techniques can assist in diagnosing the aetiology of poor performance of wastewater treatment works (WWTWs). In South Africa, most facilities rely solely on physicochemical indicators, treating reactors as âblack-boxesâ, with the result that process adjustments are often delayed, to the detriment of the environment. This study was performed in order to gain insight into the filamentous population found in activated sludge in Cape Town WWTWs, to compare these with other global and local literature findings, and to build capacity in this science. Physicochemical and plant performance parameters, in terms of nutrient removal and settling, were obtained from routine operational data and assessed in conjunction with the microscopic analyses of activated sludge samples taken over a 6-month period. Hypotheses on the links between filament types and/or plant configurations and/or operational parameters were formulated using existing literature. In order of prevalence, the five most common dominant filament species in 96 activated sludge samples were: Eikelboom Type 0092, Eikelboom Type 1851, nocardioforms, Microthrix parvicella and Eikelboom Type 021N. In order to compile a statistically significant database, it is recommended that an extensive nationwide study is conducted to link filament types with plant configurations, operational parameters and geographical locations.Keywords: activated sludge, bulking, identification, filament, Type 009
Selection of diazotrophic bacterial communities in biological sand filter mesocosms used for the treatment of phenolic-laden wastewater
Agri effluents such as winery or olive mill waste-waters are characterized by high phenolic concentrations. These compounds are highly toxic and generally refractory to biodegradation. Biological sand filters (BSFs) represent inexpensive, environmentally friendly, and sustainable wastewater treatment systems which rely vastly on microbial catabolic processes. Using denaturing gradient gel electrophoresis and terminal-restriction fragment length polymorphism, this study aimed to assess the impact of increasing concentrations of synthetic phenolic-rich wastewater, ranging from 96 mg Lâ1 gallic acid and138 mg Lâ1 vanillin (i.e., a total chemical oxygen demand (COD) of 234 mg Lâ1) to 2,400mg Lâ1 gallic acid and 3,442 mg Lâ1 vanillin (5,842 mg COD Lâ1), on bacterialcommunities and the specific functional diazotrophic community from BSF mesocosms. This amendment procedure instigated efficient BSF phenolic removal, significant modifications of the bacterial communities, and notably led to the selection of a phenolic-resistant and less diverse diazotrophic community. This suggests that bioavailable N is crucial in the functioning of biological treatment processes involving microbial communities, and thus that functional alterations in the bacterial communities in BSFs ensure provision of sufficient bioavailable nitrogen for the degradation of wastewater with a high C/N ratio.Web of Scienc
Assessment of a DNA vaccine encoding an anchored-glycosylphosphatidylinositol tegumental antigen complexed to protamine sulphate on immunoprotection against murine schistosomiasis
Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018.
Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence, and mitotic catastrophe, we discuss the utility of neologisms that refer to highly specialized instances of these processes. The mission of the NCCD is to provide a widely accepted nomenclature on cell death in support of the continued development of the field
Programmed cell death and its role in inflammation
Cell death plays an important role in the regulation of inflammation and may be the result of inflammation. The maintenance of tissue homeostasis necessitates both the recognition and removal of invading microbial pathogens as well as the clearance of dying cells. In the past few decades, emerging knowledge on cell death and inflammation has enriched our molecular understanding of the signaling pathways that mediate various programs of cell death and multiple types of inflammatory responses. This review provides an overview of the major types of cell death related to inflammation. Modification of cell death pathways is likely to be a logical therapeutic target for inflammatory diseases
Analysis of substrate degradation, metabolite formation and microbial community responses in sand bioreactors treating winery wastewater: A comparative study
There is a global need for the implementation of more cost-effective green technologies for the treatment
of effluent from wineries. However, systems reliant on microbial biodegradation may be adversely
affected by the highly seasonal character of cellar waste. In this study, the biodegradation of two different
formulations of winery effluent in sand bioreactors was compared. The degradation of organic substrates
and formation of metabolites was monitored by physicochemical analyses of pore water and final
effluent samples. Changes in the bacterial community structures were detected using molecular
fingerprinting. In wastewater with an overall COD of 2027 mg/L, a formulation with a high concentration
of acetate (800 mg COD/L) was more recalcitrant to degradation than a formulation with a high concentration
of glucose (800 mg COD/L). Ethanol, glucose and phenolics were degraded preferentially in
the deeper layers of the sand bioreactors (average Eh 25 mV) than in the superficial layers (average Eh
102 mV). The redox status also played a pivotal role on the bacterial community composition. The study
yielded valuable insight that can be utilized in the design (configuration and operation) of full scale sand
bioreactors.Water Research Commission
of South Africa (K5/2104) and the Cape Peninsula University of
Technology for funding of this project and the National Research
Foundation of South Africa for the provision of student/internship
bursaries for Ms Zaida Palmer and Ms Shafieka Isaac
Bioremediation of synthetic winery wastewater using sand columns containing Phillipi sand
CPUT Research Da
Characterisation of winery wastewater from continuous flow settling basins and waste stabilisation ponds over the course of 1 year: implications for biological wastewater treatment and land application
Wineries generate 0.2 to 4 L of wastewater per litre of wine produced. Many cellars make use of
irrigation as a means of disposal, either directly or after storage. In order to consider the potential
downstream impacts of storage/no storage, this study critically compared the seasonal organic and
inorganic composition of fresh winery effluent with effluent that had been stored in waste
stabilisation ponds. Ethanol and short chain volatile fatty acids were the main contributors to
chemical oxygen demand (COD), with average concentrations of 2,086 and 882 mgCOD/L,
respectively. Total phenolics were typically present in concentrations <100 mg/L. The concentration
of sodium from cleaning agents was higher in the non-crush season, while the converse was true for
organics. The effluent was nitrogen-deficient for biological treatment, with COD:N ratios of 0.09 to
1.2. There was an accumulation of propionic and butyric acid during storage. The composition of the
pond effluent was more stable in character, and it is possible that bacterial and algal nitrogen fixation
in such systems may enhance biological wastewater treatment by natural nitrogen supplementation.
It is therefore recommended that if land requirements can be met, winery effluent should be stored
in ponds prior to treatment
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