Sewage Pool Research Articles

Distribution and diversity of aquatic insects in different water bodies of Qatar.

Aquatic insect fauna remains an important tool for bio indication of environmental disturbance, while maintaining a healthy aquatic system. The purpose of the study was to document and to identify the diversity and distribution patterns of aquatic insect, a highly ignored aspect from the Qatar. Following the standard procedures, the samples were collected from aquatic habitats during the period October 2015 to May 2017 on monthly basis. A total of 11,287 individuals, belonging to 6 orders were captured. Dipterans were the abundant with the percentages of 71.01 (n=8,015), while the lowest percentage was observed for Coleoptera 0.04 (n=05). Twelve insects families were identified, among these five were reported under Diptera, followed by Hemiptera (03), while Coleoptera, Tricoptera, Odonata, and Ephemeroptera were represented by single families. Among the selected localities, Dipterans were collected from 10 stations, followed by Hemiptera (9), Coleoptera (4), Odonota (4), Ephemeroptera (3) and Trichoptera (1) respectively. Among the water bodies samples, streams were the most preferred habitats (n=2,767), while drinking water pools were the least (27). Moreover, the highest Simpson diversity index of 1.48 and lowest of 0.47 was recorded for flooded sewage pool and plastic containers respectively, while the low evenness values were observed for ponds, and less than 1 Margalef's diversity values were seen for all habitats. This study documents the patterns of the diversity and distribution of aquatic insects, and provides a baseline for the future studies from Qatar.

Study on VOC Emission Accounting Method from Sewage Pool in Oilfield Based on COMSOL and Response Surface Methodology

Study on VOC Emission Accounting Method from Sewage Pool in Oilfield Based on COMSOL and Response Surface Methodology

Bacillus amyloliquefaciens CU33 fermented feather meal-soybean meal product improves the intestinal morphology to promote the growth performance of broilers

This study is aimed to select optimum keratin degradation ability from Bacillus strains for feather meal-soybean meal fermentation, and favorably water content for the strain during fermentation of feather meal-soybean meal, and finally investigate the effects of the fermented feather meal-soybean meal product (FFSMP) on growth performance, carcass trait, clinical blood biochemistry, and intestinal morphology of broilers. Thirty-six bacteria strains from soil, sewage pool, and feather waste were screened and selected Bacillus subtilis var. natto N21 (N21), B. subtilis CU14 (CU14), and B. amyloliquefaciens CU33 (CU33) with better keratinase activity and feather-degrading rate. The result of trial 1 showed that the FFSMP produced by CU33 had the optimum physiochemical characterizations, amino acid composition and feeding performance for broilers. Hence the effects of water content (45, 50, 55, and 60%) on FFMSP fermentation of CU33 were investigated in trial 2. Result showed that pH value, counts of Bacillus-like bacteria, γ-PGA, viscosity, surfactin yield and odor all significantly increased according to the water content (P < 0.05). The protease activity reached significantly highest in the 55% and 60% water content groups (P < 0.01). The broilers performance of 55% and 60% water content group were significantly higher than control group (P < 0.05) in weight gain (WG), feed intake (b) at 0 to 21-d-old and the WG, feed conversion ratio (FCR), and production efficiency factor at 0 to 35-d-old, and could reach the similar growth performance as fish meal group (P > 0.05). The fermentation groups significantly decreased urea nitrogen (P < 0.05) and increased creatinine (P < 0.05) in the blood. The fermentation groups also significantly decreased the crypt depth in the duodenum (P < 0.05) and increased villus height to crypt depth ratio of the duodenum (P < 0.05). In conclusion, CU33 shows the best degradation rate for feather and keratinase activity, and the FFSMP with a water content of 50% to 60% during fermentation is suggested. Diets supplemented with 5% FFSMP can promote the growth of broilers by improving the morphology of the duodenum and achieve the feeding effect of high-quality fish meal.

Research on VOCs Treatment Technology of Oily Sewage Pool in Oil Field

Research on VOCs Treatment Technology of Oily Sewage Pool in Oil Field

Pollution Characteristics and Comprehensive Evaluation of Soil Organic Compounds at a Chemical Contaminated Site

Urban soil is one of the main components of urban ecosystem. Taking organic pollution in a chemical plant after relocation as the research object, which is left behind by a chemical plant after relocation, 13 deep soil samples were collected. According to the requirements of “Soil environmental quality Risk control standard for soil contamination of development land” (GB36600-2018), 43 organic contents were tested and analyzed. Mass ratio statistical analysis, single pollution index method and Nemerow synthetic evaluation index were used to analyze the organic pollution in the site. Results show that chloroform, benzene, trichloroethylene (TCE), 1,2-dichloropropane and 1,2,3-trichloropropane were significantly enriched in the reactor and the sewage pool, and the pollution depth was up to 10m. This shows that the chemical plant has a great impact on the site, and there may be leakage or stolen discharge, which is also an important source of soil organic pollution in this area, so detailed monitoring and remediation work should be carried out in the later stage.

Detection of New Delhi metallo-beta-lactamase enzyme gene bla NDM-1 associated with the Int-1 gene in Gram-negative bacteria collected from the effluent treatment plant of a tuberculosis care hospital in Delhi, India.

Background Organisms possessing the bla NDM-1 gene (responsible for carbapenem resistance) with a class-1 integron can acquire many other antibiotic resistance genes from the community sewage pool and become multidrug-resistant superbugs. In this regard, hospital sewage, which contains a large quantity of residual antibiotics, metals and disinfectants, is being recognized as a significant cause of antimicrobial resistance (AMR) origination and spread across the major centres of the world and is thus routinely investigated as a marker for tracing the origin of drug resistance. Therefore, in this study, an attempt has been made to identify and characterize the carbapenem-resistant microbes associated with integron genes amongst the organisms isolated from the effluent treatment plant (ETP) installed in a tertiary respiratory care hospital in Delhi, India.Methods One hundred and thirty-eight organisms belonging to Escherichia , Klebsiella , Pseudomonas and Acinetobacter spp. were collected from the incoming and outgoing sewage lines of the ETP. Carbapenem sensitivity and characterization was performed by the imipenem and imipenem-EDTA disc diffusion method. Later DNA extraction and PCR steps were performed for the Int-1 and bla NDM-1 genes.Results Of the 138 organisms, 86 (62.3 %) were imipenem-resistant (P<0.05). One hundred and twenty-four (89.9 %) organisms had one or both of the genes. Overall, the bla NDM-1 gene (genotypic resistance) was present in 71 % (98/138) of organisms. 53.6 % (74/138) organisms were double gene-positive (bla NDM-1 + Int-1), of which 40 were producing the metallo-beta-lactamase enzyme, making up almost 28.9 % (40/138) of the collected organisms.Conclusion The current study strengthens the hypothesis that Carbapenem resistant organisms are in a high-circulation burden through the human gut and hospital ETPs are providing an environment for resistance origination and amplification.

The Enrichment and Transfer of Heavy Metals for Two Ferns in Pb-Zn Tailing

The enrichment and transfer of 8 heavy metals of Equisetum ramosissimum and Pteris vittata growing naturally close to edge of the sewage pool in Bencun Pb-Zn Tailing, Eastern Guangdong were investigated. The results indicated that the pollution of Cd, Pb, Hg, Zn was very severe in this tailing, followed by Cu and Mn. The potential ecological risk of heavy metals was assessed to be very strong based on soil background values of Guangdong Province and at high risk according to criteria of the second grade State Soil Environmental Quality Standard, and Cd, Hg, Pb were the main factors leading to potential ecological risk. The content of 8 heavy metals in the two ferns did not reach critical content of hyperaccumulator, so neither of them was typical hyperaccumulator, but both had a certain tolerance to these heavy metal pollution. Underground parts of Pteris vittata had an enrichment coefficient above 1 and that of Equisetum ramosissimum had a value near 1, therefore the two ferns could be utilized as potential enrichment plants. The two ferns have strong adaptability to the tailing habitat and can be used as pioneers in ecological restoration of Pb-Zn tailings.

Identification of a yeast strain able to oxidize and remove sulfide high efficiently.

Hydrogen sulfide is a common odor gas of volatile sulfur-containing compound. The emission of hydrogen sulfide in the waste gas from industrial processing and agricultural operations could cause air pollution to the surrounding environment. The aim of this study was screening and isolation of wild yeast strains from the sludge of sewage pool in the fishmeal processing plant to remove hydrogen sulfide odor. A yeast strain ZJY-7 was obtained. Its hydrogen sulfide removal efficiency was 97.1%. The morphology studies were investigated using microscope and scanning electron microscope. The yeast isolate was then identified by biochemical tests using API 20 C AUX strip and sequencing 26S rDNA genes. Both biochemical tests analysis and the molecular identification indicated that the yeast isolate ZJY-7 was Candida tropicalis ZJY-7. The NCBI GenBank accession number is KX259479. Batch tests showed that the yeast strain tolerated up to 300mg/l of dissolved S2- concentration. The yeast also tolerated a wide pH range (2.5-9.0). The optimal initial sulfide concentration of C. tropicalis ZJY-7 on sulfide oxidation and sulfate generation was 200mg/l, and at initial pH value 6. The highest accumulated sulfate was 91.8mg/l at 48h. These results broadened the range of sulfide-oxidizing organism and new application of C. tropicalis on the control of hydrogen sulfide odor pollution. The yeast may have potential to be used in bioreactor for removal of hydrogen sulfide gas.

Ecological desert environment suffers from industrial wastewater pollution in northwestern China

There is an increasing number of high-energy and waterconsumption industries locating in arid regions of China. In recent years a number of pollution incidents have occurred in these desert areas, damaging the desert ecosystem, in some cases irreparably. Using the Tengger Desert and Mu Us Desert as two cases in point, the serious situation of uninhibited discharge of industrial wastewater in desert regions is discussed. How can governments effectively environmentally protect fragile desert environments and at the same time sustainably develop these areas? The authors point out the vulnerability of the ecosystem in desert areas and the prerequisites to its protection that involve the immediate strengthening of supervision, reporting and enforcement of waste disposal from manufacturing and chemical industries. China is one of the countries that suffers from the most serious desertification in the world, with 2.622 million km land area having become desert, over 27 % of the national territorial area (Ministry of Land and Resources of the People’s Republic of China 2011). The local ecosystem in areas of desertification is fragile, mainly due to the low biodiversity, poor ability of self-regulation and simple community structure (Ma et al. 1998). More and more manufacturing and chemical plants were built and caused problems of groundwater overexploitation and excessive wastewater discharge, which led to the formation of a number of large sewage pools. In some incidents, the wastewater seeped into groundwater through a sand layer and led to the deterioration of groundwater quality and the death of plants. Currently, to control the wastewater discharge into deserts and restore their local ecosystems, there is an urgent need for the government to improve the regulations and their enforcement. In September 2014, The Beijing News (2014a, c) reported that several large wastewater pools had been detected in the hinterland of the Tengger Desert and Mu Us Desert. Tengger Desert is located between the Mount Helan and the Mount Yabulai in northwest China and the Mu Us Desert is located in the south part of the Ordos region in Inner Mongolia and adjacent with Shaanxi and Ningxia. These pools were factory-waste evaporation ponds that were improperly planned for the local chemical industry use (Caixin Online 2014a). All of the pools of wastewater, each of which is as large as a football field, are full of black chemical wastewater and give off a terrible smell. The wastewater accumulated in the pools and was left to evaporate. Thereafter, the viscous sediments at the bottom were dug out and buried directly in the desert without any treatment, which recontaminated the surrounding environment (The Beijing News 2014a). The pollution is not only making the ecosystem of the desert oasis breakdown, but also having a strong negative impact on the water security. According to some local herdsmen, many livestock have been moved away from this region because of the serious grassland deterioration and environmental pollution. The cases of chemical wastewater drainage and groundwater pollution in the Tengger Desert were reported in March 2014, but drew little attention from the local governments. To maintain the local fiscal revenue, the governments hid the truth of these events from the public using the excuse of insufficient supervision and became the shelters of the & Ming Dou dou_ming@163.com

Experimental research on the high-density polyethylene anti-permeable membrane of waste-water pools

Since a high-density polyethylene membrane has good mechanical properties and stable chemical properties, it is widely used in all kinds of anti-permeable layers. But for a sewage pool of a drilling engineering in the western desert oil field, it is not only facing a high temperature and drying environment, but also quite a complex drilling fluid composition. Yet an experimental study system on application has not set up in China. According to the working environment of the high-density polyethylene membrane, a series of aging tests are carried out in the paper. Measured the change value of the high-density polyethylene membrane, mechanical properties are expressed directly the aging properties of high-density polyethylene membranes.

Experimental and modeling study of pure terephthalic acid (PTA) wastewater transport in the vadose zone.

PTA wastewater discharged from a factory was selected as the research object in this project and CODcr was selected as the characteristic pollution factor. Static adsorption and soil column leaching experiments of silty clay and clayey soil were carried out to study the adsorption, bio-degradation and dispersion coefficient of CODcr in PTA wastewater. Hydrus-1D was used to build the convection-diffusion model to demonstrate the migration of PTA wastewater in the vadose zone. The results indicate that silty clay and clayey soil in the vadose zone can adsorb, degrade and impede the contaminants in PTA wastewater; however, the coefficient of adsorption and degradation were very low, they were down to 0.0002 L g(-1), 0.0003 L g(-1) and 0.0097 d(-1), 0.0077 d(-1) for silty clay and clayey soil, respectively. Under the virtual condition that, wastewater in the sewage pool is 5 m deep, CODcr concentration is 4000 mg L(-1), vadose zone is 21 m, PTA wastewater will reach the phreatic surface after 20.87 years. When wastewater in the sewage pool is 7 m with other conditions unchanged, after 17.18 years PTA wastewater will reach groundwater. The results show that there is a higher pollution risk for groundwater if we do not take any anti-seepage measures.

INNER FLOW FIELD OF POOL MIXED BY THREE SUBMERSIBLE MIXERS

To study the agitating effect of submersible mixers in a square sewage treatment pool, the three-dimensional modeling Pro/E software was adopted to establish the physical model. The large-scale computational fluid dynamics software FLUENT6.3 was used, and the large-scale software ICEM was selected to build an unstructured tetrahedron grid of the sewage treatment pool. Next, the sewage treatment pool was numerically simulated by RNG k-ε turbulent model and move coordinate system technology. The macrofluid field and the flow field distribution of each section were analyzed to observe the efficiency of each submersible mixer. The average velocity of the fluid and the stirring volume were studied simultaneously. Results show that, under the action of three mixers, fluid of the sewage pool forms a continuous circulating water flow. The fluid is mixed adequately. The average velocity of fluid in the pool is at around 0.3 m/s, and the fluid mixing area in the pool is more than 90%, which is in agreement with the working requirements. Consequently, it can provide a reference basis for the practical engineering application of submersible mixers by using this method.

Study on velocity distribution in a pool by submersible mixers

To study the distribution of submersible mixers and agitating effect in the sewage treatment pool, Pro/E software was utilized to build the three-dimensional model. Then, the large-scale computational fluid dynamics software FLUENT6.3 was used. ICEM software was used to build unstructured grid of sewage treatment pool. After that, the sewage treatment pool was numerically simulated by dynamic coordinate system technology and RNG k-ε turbulent model and PIOS algorithm. The macro fluid field and each section velocity flow field distribution were analyzed to observe the efficiency of each submersible mixer. The average velocity and mixing area in the sewage pool were studied simultaneously. Results show that: the preferred project B, two submersible mixers speed is 980 r/min, and setting angles are all 30°. Fluid mixing area in the pool has reached more than 95%. Under the action of two mixers, the fluid in the sewage pool form a continuous circulating water flow. The fluid is mixed adequately and average velocity of fluid in the pool is at around 0.241m/s, which agreed with the work requirements. Consequently it can provide a reference basis for practical engineering application of submersible mixers by using this method.

Numerical Simulation of Benzene in Soil Contaminant Transport by Finite Difference Method

In this paper, the two-dimensional saturated soil adsorption and desorption of contaminant transport model was considered, and it is discreted by the Crank-Nicolson difference scheme method. The benzene contaminant in the original organic chemical cesspool was determined, and the transportation of benzene contaminant is simulated by Matlab software. Simulation results show that the benzene concentration in the sewage pool reduced to 1.15mg/kg, where can be used for various soil types by the migration effect of the soil after a decade. This established model and simulation methods can be used for estimating other existing benzene contaminated soil pollution.

Analysis of the immune-inducible transcriptome from microbial stress resistant, rat-tailed maggots of the drone fly Eristalis tenax

BackgroundThe saprophagous and coprophagous maggots of the drone fly Eristalis tenax (Insecta, Diptera) have evolved the unique ability to survive in aquatic habitats with extreme microbial stress such as drains, sewage pools, and farmyard liquid manure storage pits. Therefore, they represent suitable models for the investigation of trade-offs between the benefits resulting from colonization of habitats lacking predators, parasitoids, or competitors and the investment in immunity against microbial stress. In this study, we screened for genes in E. tenax that are induced upon septic injury. Suppression subtractive hybridization was performed to selectively amplify and identify cDNAs that are differentially expressed in response to injected crude bacterial endotoxin (LPS).ResultsUntreated E. tenax maggots exhibit significant antibacterial activity in the hemolymph which strongly increases upon challenge with LPS. In order to identify effector molecules contributing to this microbial defense we constructed a subtractive cDNA library using RNA samples from untreated and LPS injected maggots. Analysis of 288 cDNAs revealed induced expression of 117 cDNAs corresponding to 30 novel gene clusters in E. tenax. Among these immune-inducible transcripts we found homologues of known genes from other Diptera such as Drosophila and Anopheles that mediate pathogen recognition (e.g. peptidoglycan recognition protein) or immune-related signaling (e.g. relish). As predicted, we determined a high diversity of novel putative antimicrobial peptides including one E. tenax defensin.ConclusionWe identified 30 novel genes of E. tenax that were induced in response to septic injury including novel putative antimicrobial peptides. Further analysis of these immune-related effector molecules from Eristalis may help to elucidate the interdependency of ecological adaptation and molecular evolution of the innate immunity in Diptera.

Ecological niche modeling as a predictive tool: silver and bighead carps in North America

The silver carp and bighead carp (Cyprinidae), native to eastern Asia, have been introduced into the United States in attempts to improve water quality in aquaculture ponds, reservoirs, and sewage pools. Escaped or released specimens from fish farms have been reported in many states, and both species are already locally established and spreading further. We used the Genetic Algorithm for Rule-set Prediction (GARP) to model the niches of these two carps in their native ranges using hydrologic and general environmental parameters in concert with native distributional data. The results accurately predicted native occurrence data withheld from the modeling process (P < 0.01). We then projected the niche models onto the North American landscape. Native niche range models significantly predicted known occurrence data from North American introductions (P < 0.001). Further, the models suggest that both species have the potential of spreading throughout the eastern U.S. and selected areas of the West Coast.

City Management, Local Power, and Social Practice

The metropolises of Brazil, as in most of Latin America, give the appearance of two different cities in one. There is the city of curbs and gutters and sidewalks and pavement, on the one hand, and the city of raw sewage pools and uncollected garbage, on the other. A large percentage of urban inhabitants, sometimes half or more, are squatter citizens, as Hardoy and Satterthwaite (1989) have called them. Unemployed, underemployed, or self-employed, they are always severely underpaid. Their homes are built illegally, on land occupied illegally, and their work is also outside the official norms, standards, and regulations of the formal labor market. Spatially segregated on the hills in the suburbs or on the banks of rivers, this part of the city, the substandard city, is nonetheless closely integrated, socially and economically, with the planned and fully urbanized part of the metropolis (Perlman, 1976). The marginal condition of the poor has, over the years, been mitigated to some extent, most apparently in the juridic sphere, as collective conflicts over land tenure brought about changes in Brazil's legal system (Moura, 1993a, 1995). The apparent dichotomy between the formal/informal, legal/ illegal, planned/substandard metropolis is caused by the extreme income, social, cultural, and political disparities and inequalities that exist within the metropolis. Throughout the history of Brazil, urban policy has led to a pattern of social exclusion. This exclusion was intensified by the country's political and economic elite when urban modernization was attempted in the early 20th century. In the face of demands for an export-oriented economy, the elite established policy guidelines according to which progress meant transporta-