Sludge accumulation pattern on the plate settlers and the optimum washout

2019 ◽  
Vol 144 ◽  
pp. 65-71 ◽  
Author(s):  
Moharram Fouad ◽  
Hoda El-Gamal ◽  
Yasmin Abdullah
Keyword(s):  
Accumulation Pattern ◽  
Sludge Accumulation

scholarly journals The performance of sludge blanket clarifier against conventional settler under high water turbidity conditions

2018 ◽  
Vol 13 (3) ◽  
pp. 642-653 ◽  
Author(s):  
Moharram Fouad ◽  
Shaban Hassan
Keyword(s):  
Removal Efficiency ◽  
Field Data ◽  
High Water ◽  
Ease Of Use ◽  
Turbid Water ◽  
Water Turbidity ◽  
Turbidity Removal ◽  
Accumulation Pattern ◽  
Algae Removal ◽  
Sludge Accumulation

Abstract The performance of a sludge blanket clarifier was evaluated and compared to conventional settlers under high levels of turbidity and algae in the field and experimentally. Field data of sludge blanket and conventional clarifier operation were observed simultaneously for the treatment of highly turbid water. In addition, a comparison was carried out on turbidity removal efficiency, algae removal, and sludge accumulation pattern. Finally, these systems were simulated in the laboratory and operated to treat turbid water with high levels of turbidity and algae up to 80 NTU and 109cells/l respectively. Field data confirmed that the sludge blanket clarifier equipped with upper sludge cones has a high removal efficiency of turbidity and algae, ease of use and has insignificant sludge accumulation compared to the conventional settler. Further, laboratory experiments have confirmed that sludge blanket clarifier is also very effective for the treatment of high algae concentrations up to 109cells/l, with a short retention time, compared to a conventional settler, which was not effective under these conditions.

Sludge accumulation pattern inside oxidation ditch case study

2014 ◽  
Vol 69 (12) ◽  
pp. 2468-2475 ◽  
Author(s):  
Moharram Fouad ◽  
Ahmed El-Morsy
Keyword(s):  
Suspended Solids ◽  
Municipal Wastewater ◽  
Weather Conditions ◽  
System Failure ◽  
Oxidation Ditch ◽  
Accumulation Pattern ◽  
Mixed Liquor ◽  
Economical Design ◽  
Sludge Accumulation

The sludge accumulation pattern of an oxidation ditch (OD) plant treating municipal wastewater was observed under dry and wet weather conditions, during 3 years of operation. The accumulation patterns along the ditches and their rates were revealed. In addition, the composition of the accumulation was investigated. Finally, the ratio of sand and volatile particles, mixed liquor suspended solids (MLSS), and mixed liquor volatile suspended solids, as well as the removal efficiency were also observed against the accumulated sludge. Further, a laboratory-scale channel was used to investigate the settleability of grit after mixing with variable values of MLSS. The observed results indicated that the economical design and operation of ODs using a velocity value between 0.3–0.35 m/s is not recommended, to avoid the settling of all solids. High values of MLSS and sludge age need high horizontal velocity (more than 0.35 m/s) and more power to avoid settling problems and system failure. The influence of flow velocity on the sludge settleability was studied, enabling better planning of future ditch design and operation.

Sludge accumulation pattern in an anaerobic pond under Mediterranean climatic conditions

2003 ◽  
Vol 37 (3) ◽  
pp. 634-644 ◽  
Author(s):  
A Papadopoulos ◽  
G Parisopoulos ◽  
F Papadopoulos ◽  
A Karteris
Keyword(s):  
Climatic Conditions ◽  
Accumulation Pattern ◽  
Sludge Accumulation

scholarly journals Explore the gene network regulating the composition of fatty acids in cottonseed

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lihong Ma ◽  
Xinqi Cheng ◽  
Chuan Wang ◽  
Xinyu Zhang ◽  
Fei Xue ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Linoleic Acid ◽  
Linolenic Acid ◽  
Gene Network ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Accumulation Pattern ◽  
Time Points ◽  
Expression Characteristics

Abstract Background Cottonseed is one of the major sources of vegetable oil. Analysis of the dynamic changes of fatty acid components and the genes regulating the composition of fatty acids of cottonseed oil is of great significance for understanding the biological processes underlying biosynthesis of fatty acids and for genetic improving the oil nutritional qualities. Results In this study, we investigated the dynamic relationship of 13 fatty acid components at 12 developmental time points of cottonseed (Gossypium hirsutum L.) and generated cottonseed transcriptome of the 12 time points. At 5–15 day post anthesis (DPA), the contents of polyunsaturated linolenic acid (C18:3n-3) and saturated stearic acid (C18:0) were higher, while linoleic acid (C18:2n-6) was mainly synthesized after 15 DPA. Using 5 DPA as a reference, 15,647 non-redundant differentially expressed genes were identified in 10–60 DPA cottonseed. Co-expression gene network analysis identified six modules containing 3275 genes significantly associated with middle-late seed developmental stages and enriched with genes related to the linoleic acid metabolic pathway and α-linolenic acid metabolism. Genes (Gh_D03G0588 and Gh_A02G1788) encoding stearoyl-ACP desaturase were identified as hub genes and significantly up-regulated at 25 DPA. They seemed to play a decisive role in determining the ratio of saturated fatty acids to unsaturated fatty acids. FAD2 genes (Gh_A13G1850 and Gh_D13G2238) were highly expressed at 25–50 DPA, eventually leading to the high content of C18:2n-6 in cottonseed. The content of C18:3n-3 was significantly decreased from 5 DPA (7.44%) to 25 DPA (0.11%) and correlated with the expression characteristics of Gh_A09G0848 and Gh_D09G0870. Conclusions These results contribute to our understanding on the relationship between the accumulation pattern of fatty acid components and the expression characteristics of key genes involved in fatty acid biosynthesis during the entire period of cottonseed development.

Regulation of proboscipedia in Drosophila by Homeotic Selector Genes

Genetics ◽  
2000 ◽  
Vol 156 (1) ◽  
pp. 183-194
Author(s):  
Douglas B Rusch ◽  
Thomas C Kaufman
Keyword(s):  
Expression Pattern ◽  
Regulatory Element ◽  
Polycomb Group ◽  
Accumulation Pattern ◽  
Cis Acting ◽  
Polycomb Group Genes ◽  
Gap Genes ◽  
Combined Action ◽  
Selector Genes

Abstract The gene proboscipedia (pb) is a member of the Antennapedia complex in Drosophila and is required for the proper specification of the adult mouthparts. In the embryo, pb expression serves no known function despite having an accumulation pattern in the mouthpart anlagen that is conserved across several insect orders. We have identified several of the genes necessary to generate this embryonic pattern of expression. These genes can be roughly split into three categories based on their time of action during development. First, prior to the expression of pb, the gap genes are required to specify the domains where pb may be expressed. Second, the initial expression pattern of pb is controlled by the combined action of the genes Deformed (Dfd), Sex combs reduced (Scr), cap'n'collar (cnc), and teashirt (tsh). Lastly, maintenance of this expression pattern later in development is dependent on the action of a subset of the Polycomb group genes. These interactions are mediated in part through a 500-bp regulatory element in the second intron of pb. We further show that Dfd protein binds in vitro to sequences found in this fragment. This is the first clear demonstration of autonomous positive cross-regulation of one Hox gene by another in Drosophila melanogaster and the binding of Dfd to a cis-acting regulatory element indicates that this control might be direct.

scholarly journals Evaluation of micro-energy dispersive X-ray fluorescence and histochemical tests for aluminium detection in plants from High Altitude Rocky Complexes, Southeast Brazil

2014 ◽  
Vol 86 (1) ◽  
pp. 285-296 ◽  
Author(s):  
NAIARA V. CAMPOS ◽  
TIAGO A.R. PEREIRA ◽  
MARIANA F. MACHADO ◽  
MARCELO B.B. GUERRA ◽  
GLÁUCIA S. TOLENTINO ◽  
...  
Keyword(s):  
High Altitude ◽  
Accumulation Pattern ◽  
X Ray ◽  
Edx Analysis ◽  
Lycopodium Clavatum ◽  
Histochemical Tests ◽  
Ecological Success ◽  
Positive Correlations ◽  
Non Destructive ◽  
Potential Tool

The soils developed under High Altitude Rocky Complexes in Brazil are generally of very low chemical fertility, with low base saturation and high exchangeable aluminium concentration. This stressful condition imposes evolutionary pressures that lead to ecological success of plant species that are able to tolerate or accumulate high amounts of aluminium. Several analytical methods are currently available for elemental mapping of biological structures, such as micro-X-ray fluorescence (μ-EDX) and histochemical tests. The aim of this study was to combine μ-EDX analysis and histochemical tests to quantify aluminium in plants from High Altitude Rocky Complexes, identifying the main sites for Al-accumulation. Among the studied species, five showed total Al concentration higher than 1000 mg kg−1. The main Al-hyperaccumulator plants, Lavoisiera pectinata, Lycopodium clavatum and Trembleya parviflora presented positive reactions in the histochemical tests using Chrome Azurol and Aluminon. Strong positive correlations were observed between the total Al concentrations and data obtained by μ-EDX analysis. The μ-EDX analysis is a potential tool to map and quantify Al in hyperaccumulator species, and a valuable technique due to its non-destructive capacity. Histochemical tests can be helpful to indicate the accumulation pattern of samples before they are submitted for further μ-EDX scrutiny.

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