Domestic Sewage Treatment Plant Research Articles

Antibiofilm activity of selenium nanorods against multidrug-resistant Staphylococcus aureus

Objective: This study aimed at the synthesis and application of selenium nanoparticles (SeNPs) against biofilm formation by multidrug-resistant (MDR) Staphylococcus aureus isolated from the domestic sewage treatment plant. Materials and Methods: Chemically synthesized SeNPs were characterized using Ultraviolet–visible spectroscopy, X-ray diffraction, and high resolution scanning electron microscopy (HR-SEM).. Bacteria were isolated from domestic sewage water samples and characterized and identified using standard techniques. The drug resistance pattern of the isolates was determined using a disk diffusion assay. Biofilms of this MDR isolate were established (microtiter plate method—colorimetric assay and a slide method). Minimum inhibitory concentrations (MIC) of selenium nanorods (SeNRs) and their effect on biofilm formation were established using a colorimetric method. Results: The HR-SEM analysis of nanomaterials revealed its shape (rod), size (between 85 nm and 275 nm), and purity of the material. The disk diffusion assay attributed MDR status to an isolate that was identified and found to be S. aureus, a pathogenic bacterium isolated from an environmental sample. The MICs of antibiotics against biofilm were found to be at least threefold higher than those against the planktonic state. In the presence of SeNRs, biofilm formation was inhibited. Conclusion: SeNRs synthesized using wet chemical method showed antibacterial activity against MDR S. aureus and inhibited biofilm formation by this organism. These SeNRs can be further developed as an alternate drug lead to combat the challenge posed by the MDR bacteria. The study has a future prospectus in investigating the mechanism of inhibition of biofilm formation and its action on preformed biofilm by this isolate.

Weak Disposability of Input and Output in a Nonparametric Production Analysis

In some production processes, unlike traditional data envelopment analysis (DEA), decision making units (DMUs) consume widely used inputs since increasing them is more favorable for improving the efficiency. Plastic wastes and rotten fruits are two instances of widely used inputs for recycling factories. In this paper, weak disposability of inputs will be presented with non-uniform profit factors for inputs, and then the model will be extended to cases which consume normal and widely used inputs, and produce desirable and undesirable outputs, simultaneously. Due to a nonlinear form of the final model, a linearization method is presented to provide a linear structure of the technology. Actually, a directional distance function approach, including weakly disposable inputs and outputs is introduced to deal with widely used inputs and undesirable outputs. Finally, the approach will be tested by applying it on some domestic sewage treatment plants in China. Results show the proposed approach can discriminate between DMUs in a rational way and less computational efforts and also it can be used for the efficiency analysis when widely used inputs and undesirable outputs are presented.

VALUE OF THE SEWAGE MANAGEMENT DEVICES IN RURAL AREAS IN THE OPINION OF LOCAL COMMUNITIES ON THE EXAMPLE OF THE WYSZKI COMMUNE

The aim of the article is to present the public reception of the implementation of household-level sewage treatment plants in the Municipality of Wyszki. The CVM method of conditional valuation was used to learn the opinion of residents on the implementation of domestic sewage treatment plants, using the willingness test for payment (WTP). The method of conditional valuation was carried out based on a survey. The research trial was conducted using direct interviews among 100 inhabitants of the commune of Wyszki. The questionnaire contained, among other things, questions about the types of sewage collection and treatment system in the municipality. For the article, the answers of the commune residents who were not connected to the sewage system or had a holding tank were considered

Study on performance test methods and test rules of small complete set of domestic sewage treatment plant

This paper describes the test methods and corresponding test rules for the appearance, function, manufacturing, strength and tightness, safety, environmental protection, reliability, economy and generality of the small domestic sewage treatment plant, it can provide technical support for the quality improvement of small domestic sewage treatment plants in China.

Study on technical standard of small complete domestic sewage treatment plant

This paper expounds the industry and policy background of small complete domestic sewage treatment plant in China, and discusses the basic principles and basic investigation of the development of technical standard for small complete domestic sewage treatment plant, the key technical contents of standard for small complete domestic sewage treatment plant are expounded. Through the development and implementation of this technical standard, it will provide standardized technical support for standardizing and improving the manufacturing level of small complete domestic sewage treatment plants in China.

ANÁLISE DA EFICIÊNCIA DO TRATAMENTO ANAERÓBIO DA MANIPUEIRA

In the processes of industrialization of cassava flour (Minihot esculenta), there is the generation of an effluent called manipueira, which requires treatment before being released into the water body. The objective of this work was to evaluate the efficiency of effluent degradation by an anaerobic reactor, using as substrate, manipueira of a flour producing industry, and, as inoculum, two distinct sludges, one from an anaerobic reactor of ascending flow (RAFA) of domestic sewage treatment plant, and another from the activated sludge system of effluent treatment of a grain producing industry. The efficiency of the process was evaluated by the physicochemical parameters: COD, BOD, total solids (TS), total volatile solids (STV), fixed total solids (STF), pH, turbidity and cyanide. Throughout the treatment there was a significant removal of Cyanide in the effluent, that is, one of the major problems of the effluent can be solved effectively via anaerobic treatment.

Effects of the constructed wetland on dissolved organic matter properties in the drainage channel of domestic sewage treatment plant in winter

As a low investment and low energy consumption wastewater treatment technology, the constructed wetland has been gradually accepted by the world. However, there is still a lack of systematic assessment on the impact of the constructed wetland on dissolved organic matter (DOM) properties in the drainage channel of domestic sewage treatment plant in winter. In this study, 3D excitation-emission matrix fluorescence spectroscopy and ultraviolet spectroscopy were combined to reveal the evolution process of DOM properties in the constructed wetland in winter. The results showed that DOC contributed more than 55% of COD in the drainage channels of Shijiazhuang domestic sewage treatment plant in winter, but the COD was significantly decreased after treated by the constructed wetland, which was mainly caused by the more extensive degradation of elements N, H, S and P in DOM. In addition, water DOM in the constructed wetland in winter was mainly contributed by microorganisms, and humus-like components in water DOM were more easily degraded than protein-like components. And humus-like components gradually transformed into protein-like components in the degradation process, and fulvic-like and humic-like components had the same decomposition fate in the constructed wetland in winter.

Analysis and Discussion on Operation Stability of Urban Sewage Treatment Plant

Based on the acceleration of the development of the national economy and the overall progress of urbanization, the discharge of domestic sewage has increased significantly, and the characteristics of domestic sewage within each city are significantly different. Therefore, the design and operational stability of urban sewage treatment plants are proposed higher requirements. In this case, the urban domestic sewage treatment plant should follow the basic principles of adapting measures to local conditions, taking into account the characteristics of domestic sewage drainage and water quality in different areas to ensure the rationality of the sewage treatment process design and the safer and more stable subsequent operations. Based on this, the article takes the urban domestic sewage treatment plant as the main research object, and focuses on the related content of its operational stability.

岷沱江流域城镇污水处理厂提标改造实例分析

岷沱江流域城镇污水处理厂提标改造实例分析

Degradation of 2,4-Dichlorophenol by Ethylenediamine-N,N′-disuccinic Acid-Modified Photo-Fenton System: Effects of Chemical Compounds Present in Natural Waters

This paper describes a study of the treatment of 2,4-dichlorophenol (2,4-DCP) with an ethylenediamine-N,N′-disuccinic-acid (EDDS)-modified photo-Fenton system in ultrapure water and different natural waters. The results showed that the EDDS-modified photo-Fenton system is adequate for 2,4-DCP degradation. Compared with a medium containing a single organic pollutant, the removal of pollutants in a more complex medium consisting of two organic compounds is slower by around 25 to 50% as a function of the organic pollutant. Moreover, 2,4-DCP can be further effectively degraded in the presence of organic materials and various inorganic ions. However, the photodegradation of 2,4-DCP in different natural waters, including natural lake water, effluent from domestic sewage treatment plants, and secondary effluent from pulp and paper mill wastewaters, is inhibited. Chemical compounds present in natural waters have different influences on the degradation of 2,4-DCP by adopting the EDDS-modified photo-Fenton system. In any case, the results obtained in this work show that the EDDS-modified photo-Fenton system can effectively degrade pollutants in a natural water body, which makes it a promising technology for treating pollutants in natural water bodies.

Analysis of Microbial Communities and Pathogen Detection in Domestic Sewage Using Metagenomic Sequencing

Wastewater contains diverse microbes, and regular microbiological screening at wastewater treatment plants is essential for monitoring the wastewater treatment and protecting environmental health. In this study, a metagenomic approach was used to characterize the microbial communities in the influent and effluent of a conventional domestic sewage treatment plant in the metropolitan city of Jeddah. Bacteria were the prevalent type of microbe in both the influent and effluent, whereas archaea and viruses were each detected at <1% abundance. Greater diversity was observed in effluent bacterial populations compared with influent, despite containing similar major taxa. These taxa consisted primarily of Proteobacteria, followed by Bacteroidetes and Firmicutes. Metagenomic analysis provided broad profiles of 87 pathogenic/opportunistic bacteria belonging to 47 distinct genera in the domestic sewage samples, with most having <1% abundance. The archaea community included 20 methanogenic genera. The virus-associated sequences were classified mainly into the families Myoviridae, Siphoviridae, and Podoviridae. Genes related to resistance to antibiotics and toxic compounds, gram-negative cell wall components, and flagellar motility in prokaryotes identified in metagenomes from both types of samples. This study provides a comprehensive understanding of microbial communities in influent and effluent samples of a conventional domestic sewage treatment plant and suggests that metagenomic analysis is a feasible approach for microbiological monitoring of wastewater treatment.

Study on Rapid Start-Up Technology Of Hydrolysis Acidification Process

Domestic sewage treatment plant is an important environmental unit in the city. The hydrolysis acidification process after the overhaul of the sewage treatment plant usually had a more than three-month’s slow started-up and run unstable, seriously affecting the daily operation and also existing big environmental risks. This paper mainly expounds the factors affecting rapid start-up such as the type of inoculating sludge, the amount of sludge, the hydraulic conditions and the bacteria start-up agent for hydrolytic acidifying bacteria. The start-up speed and operation effects of hydrolysis acidification process were improved by adjusting process parameters.

A Comparative Study on the Reduction Effect in Greenhouse Gas Emissions between the Combined Heat and Power Plant and Boiler

The purpose of this study is to compare the effect of a reduction in greenhouse gas (GHG) emissions between the combined heat and power (CHP) plant and boiler, which became the main energy-generating facilities of “anaerobic digestion” (AD) biogas produced in Korea, and analyze the GHG emissions in a life cycle. Full-scale data from two Korean “wastewater treatment plants” (WWTPs), which operated boilers and CHP plants fueled by biogas, were used in order to estimate the reduction potential of GHG emissions based on a “life cycle assessment” (LCA) approach. The GHG emissions of biogas energy facilities were divided into pre-manufacturing stages, production stages, pretreatment stages, and combustion stages, and the GHG emissions by stages were calculated by dividing them into Scope1, Scope2, and Scope3. Based on the calculated reduction intensity, a comparison of GHG reduction effects was made by assuming a scenario in which the amount of biogas produced at domestic sewage treatment plants used for boiler heating is replaced by a CHP plant. Four different scenarios for utilizing biogas are considered based on the GHG emission potential of each utilization plant. The biggest reduction was in the scenario of using all of the biogas in CHP plants and heating the anaerobic digester through district heating. GHG emissions in a life cycle were slightly higher in boilers than in CHP plants because GHG emissions generated by pre-treatment facilities were smaller than other emissions, and lower Scope2 emissions in CHP plants were due to their own use of electricity produced. It was confirmed that the CHP plant using biogas is superior to the boiler in terms of GHG reduction in a life cycle.

Sustainable treatment of real-mine drainage using crude glycerol and brewery waste as electron donors in a micro-aerobic system

This study evaluated the sustainability of biological mine drainage (MD) treatment using industrial by-products. Crude glycerol (CG) from biodiesel production and trub—a brewery waste — were used as electron donors for the biological reduction of sulfate. Batch assays were prepared using anaerobic inoculum (from a domestic sewage treatment plant) and mine drainage (from a gold mining company). The MD showed high concentrations of pollutants (in mg.L−1): 3,860.5 sulfate, 1.39 arsenic, 14.77 cadmium, 1.78 lead, 3.85 antimony, and 209.03 zin. Under a chemical oxygen demand/SO42− ratio of 3.2, sulfate removal was similar among tested substrates and positive controls of pure glycerol (PG) and ethanol, between 89.5 and 92.2 % of sulfate removed. The removal of Pb using crude glycerol was 88.3 %, while that for the other metals was above 99 %. On the other hand, the removal of all metals was over 99 % using trub. The substrates CG and trub were good carbon sources as compared to the positive controls. It is thus believed that industrial by-products are as effective as positive controls in making the MD treatment more sustainable by eliminating organic substrate acquisition costs and the consumption of products requiring treatment before environment discharge. To obtain 1 g of COD with trub, 538 mL of product is consumed at no cost. To obtain the same COD value with CG, PG and ethanol is necessary to invest US $ 0.0053, 0.1184 and 14.4, respectively.

Design of Sewerage System and Wastewater Treatment Plant in Asemrowo, Surabaya, Indonesia

Asemrowo sub-district is a high-risk area in terms of environmental health. 1113 households in Asemrowo Subdistrict still defecate (BAB) openly. In Asemrowo sub-district 89.6% of the community has a private latrine. This article attempts to design a domestic sewage and wastewater treatment plant in Asemrowo District based on Surabaya City Regulation Number 12 of 2016 concerning Water Quality Management and Wastewater Control. Meanwhile, the effluent quality refers to the Regulation of the Minister of Environment and Forestry of the Republic of Indonesia number 68 of 2016 concerning domestic wastewater quality standards. The processes of the design includes acquiring primary data from field observations, distributing community questionnaires with random sampling of 105 respondents and analyzing the quality of wastewater for references in the wastewater treatment plant (WWTP) design. The domestic wastewater distribution system uses Shallow Sewerage which is divided into 4 blocks. The diameter of the wastewater pipe used in this plan is 114 mm, 140 mm, 216 mm and 267 mm. WWTP used in blocks A, B and C use Aerobic Biofilter and Clarifier. As for WWTP block D, it uses Aerobic Biofilter.

Tandem anaerobic-aerobic degradation of ranitidine, diclofenac, and simvastatin in domestic sewage

There is a consensus among scientists that domestic sewage treatment plants are the main sources of drugs entry into the aquatic environment. Therefore, this work studies the biodegradation of the drugs ranitidine (RNT), diclofenac (DCF), and simvastatin (SVT) (50 μg L−1, each), in real domestic sewage, using a continuous anaerobic-aerobic reactor with immobilized biomass and an anaerobic batch reactor. The continuous anaerobic-aerobic reactor was operated for 6 months with hydraulic retention time (HRT) of 8 h. The initial degradation rates and the maximum oxidation capacities (MOC) of the system were estimated, achieving 90, 72, and 62% removals and 100, 93, and 72% of MOC for RNT, DCF and SVT, respectively, as well as 71% removal of soluble chemical oxygen demand (COD). RNT was degraded throughout the reactor, while DCF was degraded mainly in the two anaerobic chambers and SVT in the first anaerobic chamber. Anaerobic batches were used for the identification of biodegradation by-products (2,6-dichloro-N-(2-methylphenyl) aniline and simvastatin acid), the evaluation of the specific methanogenic activity (SMA) inhibition, and the estimation of acute and chronic ecotoxicities using the ECOSAR 1.11 software. The present study showed that, even at environmental concentrations, RNT, DCF, and SVT were capable of inhibiting the SMA. Lipophilicities dictated the behavior of those three drugs. The greater their lipophilicities, the greater the SMA inhibition and their ecotoxicity.

Metabolism of 17β-estradiol by Novosphingobium sp. ES2-1 as probed via HRMS combined with 13C3-labeling

This study investigated the biodegradation and metabolic mechanisms of 17β-estradiol (E2) by Novosphingobium sp. ES2-1 isolated from the activated sludge in a domestic sewage treatment plant (STP). It could degrade 97.1% E2 (73.5 μmol/L) in 7 d with a biodegradation half-life of 1.29 d. E2 was initially converted to estrone (E1), then to 4-hydroxyestrone (4-OH-E1), before subsequent monooxygenation reactions cleaved 4-OH-E1 into a metabolite with long-chain ketones structure (metabolite P8). However, when 4-OH-E1 was cleaved through the 4,5-seco pathway, the resulting phenol ring cleavage product could randomly condense with NH3 to yield a pyridine derivative, accompanied by the uncertain loss of a carboxy group at C4 before the condensation. The derivative was further oxidized into the metabolites with both pyridine and long-chain ketones structure (metabolite N5) through a similar formation mechanism as for P8 performed. This research presents several novel metabolites and shows that E2 can be biodegraded into the metabolite with long-chain structure through three optional pathways, thereby reducing E2 contamination.

Mercury Distribution Characteristics and Its Mass Balance in a Multifunctional Urban Wetland

The distribution characteristics and the source-sink relationship of total mercury (THg) and methyl mercury (MeHg) were studied in a wastewater treatment area and in a lake deep purification area of a multifunctional urban wetland that integrates domestic sewage treatment plant effluent, water purification, and leisure entertainment in Chongqing. The results showed that the THg concentration ranged from 1.98 ng·L-1 to 38.03 ng·L-1[average concentration was (9.10±5.84) ng·L-1] and MeHg concentration ranged from 0.09 ng·L-1 to 0.84 ng·L-1[average concentration was (0.34±0.08) ng·L-1] in an outlet of wastewater treatment area. In the deep purification zone, the THg concentration ranged from 0.37 ng·L-1 to 85.69 ng·L-1[average concentration of (6.76±2.29) ng·L-1] and the MeHg concentration ranged from 0.04 ng·L-1 to 1.47 ng·L-1[average concentration of (0.35±0.17) ng·L-1]. The interference of human activities on mercury concentration is prominent. The vertical distribution of THg in the water is consistent with that of MeHg, the surface layer has lower values than the deep layer. Material balance suggested that THg in the wetland system decreases by 155.50 g per year, and MeHg decreases by 1.65 g per year, which has a protective effect on the downstream water.

Biological diversity of Lemna aequinoctialis Welw. isolates influences biomass production and wastewater phytoremediation

Duckweeds are promising biomass producers for bioenergy and other biotechnological applications such as phytoremediation. Genetic diversity of duckweed species could influence their biotechnological potential. Nine isolates of Lemma aequinoctialis Welw. that are native of the Recife metropolitan area, Pernambuco state, in northeastern Brazil, were characterized in vitro under 1X and 0.5X Schenk and Hildebrandt (SH) culture media. Molecular identification by plastid DNA atpF-atpH barcoding sequences revealed very low genetic diversity. In contrast, exposure to environmental stimuli under 0.5X SH growth medium revealed phenotypic differentiation between the isolates. Three of the nine isolates were evaluated further for their ability to remediate the effluent from a domestic sewage treatment plant. They were able to reduce up to 94.8% of the chemical oxygen demand and to remove up to 39.3% of total nitrogen and 57.1% of phosphorus in the effluent, while producing biomass that has potential as feedstock for bioenergy production.

Asynchronous Cultivation and Domestication of Aerobic Activated Sludge to Treat the Pickle Wastewater

The domestication of activated sludge which was from domestic sewage treatment plant was studied, the effects of the pre acclimated sludge and acclimated sludge on the pickle wastewater were investigated, and the effects of pH, HRT (hydraulic retention time), aeration intensity, dissolved oxygen DO and other factors on the removal efficiency of COD were studied during the continuous operation of acclimated sludge. Experimental results show, the domesticated sludge which has been domesticated for 28 days has a stronger ability to adapt and deal with the sludge before acclimation. Under the condition of continuous water inlet and outlet, pH = 7, aeration intensity of 1000ml / (min. L), temperature of 17 °C, HRT = 4h, the removal rates of COD, NH3-N and TP were 93%, 36% and above, respectively, the effluent concentrations were 88, 1.27 and 1.17mg/L respectively, and the removal load of COD was about 1.38kgCOD / (m3.d).