City Sewage Treatment Research Articles

REDUCING THE LEVEL OF TECHNOGENIC HAZARDS IN THE DISPOSAL OF URBAN SEWAGE SLUDGE

The article deals with the issue of reducing the level of man-made danger of the negative impact of urban sewage sludge on the environment by removing heavy metals with the help of humic substances. It is noted that urban sewage sludge contains more than 90% of organic substances that can serve as organic fertilizer for agriculture. However, these sediments are practically not used as fertilizers due to the lack of approved technical and sanitary-hygienic requirements for them. At the same time, it was established that the composition of urban wastewater generated at the city's sewage treatment plants contains heavy metals, which must be removed from wastewater sediments in order to use them as fertilizers in agriculture. A new method of removing heavy metals from urban sewage sludge using humic reagents with simultaneous ultrasound treatment is proposed. Effective modes of simultaneous mixing of humins and their ultrasonic treatment have been selected, as a result of which the efficiency of heavy metals, namely iron, copper and aluminum, is improved.

Public monitoring as a tool for assessing the state of the air basin in the Ukrainian Regions

Over the recent years automated observation systems that work continuously and allow obtaining information at any time have been widely implemented. Such systems include public monitoring systems in order to receive more complete information about the quality characteristics of the air basin over Ukraine. Examples of public monitoring organizations include SaveEcoBot, EcoCity, SaveDnipro.
 The information presented on the websites of the public monitoring system contains large amount of data that are difficult to process and analyze. In order to optimize data processing, a program called PublicMonitoringParser was developed. It transforms large volumes of data presented on the Internet resource SaveEcoBot.com into compact, convenient, small files containing average monthly concentrations of pollutants and indicators of meteorological parameters. The program is written using the C# programming language and the .NET platform. The structure of the program and the principles of its operation are presented in this research.
 According to the data of the website SavEecoBot.com the developed program was applied for assessment of the air basin state of Lviv Region in 2021. In general, for most substances, monitoring data were available only at the station in the city of Lviv at the following address: 13 Plastova Str. Monitoring of PM2.5 and PM10 content was carried out across the whole region.
 It was detected that the content of NO2, SO2, NH3 exceeded the limit value. Significant excesses were also noted for the NH3 content (up to 9 – 16 MPC). It was established that the location of the public monitoring station was surrounded by industrial buildings, numerous transport industry enterprises, an oil depot for OKKO gas stations and city sewage treatment facilities. A comparison of the data obtained at stationary and automated points that monitor individual pollutants showed that the results are comparable only for the NO2 content.
 Data from automated observation points complement the network of stationary points. Currently, the existing stationary network of atmospheric pollution monitoring across most regions of Ukraine is outdated and needs to be re-equipped. In general, it is necessary to further implement automated systems that are able to characterize the state of the air basin across individual populated places in a more complete and detailed manner.

Design of a sewage sludge energy conversion technology introduction scenario for large city sewage treatment plants in Japan: Focusing on zero fuel consumption

Current thermal treatment of dewatered sludge in Japan depends on incineration with no energy recovery, but new sewage sludge recycling strategies require that energy conversion technologies be applied to sewage treatment plants (STPs) in large cities. Strategic studies of decarbonization have shown that it is necessary to prioritize the reduction of CO2 emissions associated with the direct consumption of fossil fuels to work toward decarbonization. Therefore, a scenario that would minimize external fuel dependence was set in STPs located in 14 large cities in Japan. The scenario included a plan to introduce the following systems: incineration with waste heat power generation (WHPG) under no anaerobic digestion (AD), incineration with WHPG and a dryer under AD, and solid fuel conversion with AD. Results showed that the total energy balance in FY2030 would be reduced by 90% compared to that of FY2015. Digestion gas power generation in the scenario was reduced, and WHPG (2410 TJ) and solid fuel (1931 TJ) were recovered. Compared to FY2015, greenhouse gas (GHG) emissions in FY2030 were reduced by 118%, CO2 emissions from the use of A-heavy oil were eliminated, and N2O emissions from incineration were reduced by 90%. In addition, analysis of the contribution of the scenario to GHG reduction in the boundary of national-scale sludge treatment in the sewerage sector showed that a 48% reduction was possible in FY2030 compared to FY2015, allowing Japan to fully achieve its medium-term emission reduction target (a 46% reduction) in this field.

The Application Direction of Sludge Disposal Technology in City Sewage Treatment Plant

The Application Direction of Sludge Disposal Technology in City Sewage Treatment Plant

Spatial and Seasonal Assessment of Water Quality in the Lobo Stream River Basin, Brazil Using Multivariate Statistical Techniques.

In view of the complexity of the processes associated to water quality, this study objective is to identify the main factors related to spatial and seasonal variability in water courses of the Lobo Stream River Basin. To this, multivariate statistical techniques were used. Data collection for water quality and streamflow variables were carried out monthly, from May 2018 to April 2019, at 10 monitoring points along basin's tributaries. The results show that, during the dry season, the main causes for water quality decrease are related to erosion process on the river margins, which is intensified by inadequate handling in livestock activities in some monitoring points. In the rainy season, the main causes are related to soil leaching in agricultural areas that increases the nitrogen compounds concentration and reduces water quality. However, in addition to this, it was noted that regardless the environmental conditions, the most impactful factor is the point pollution from the effluent discharge of Itirapina City sewage treatment plant, responsible for nutrient concentration increase, organic contamination, OD reduction, and, consequently, water quality deterioration. With this, the study shows how multivariate statistical analysis enables more relevant evaluation of water quality data variability and supports further studies in the basin.

G시 하수처리장의 미세플라스틱 함유량 특성과 배출량 추정

G시 하수처리장의 미세플라스틱 함유량 특성과 배출량 추정

Evaluation of the Performance Efficiency of Al-Najaf City Sewage Treatment Plant

Evaluation of the Performance Efficiency of Al-Najaf City Sewage Treatment Plant

Characterizing and explaining spatio-temporal variation of water quality in a highly disturbed river by multi-statistical techniques.

Assessing the spatio-temporal variations of surface water quality is important for water environment management. In this study, surface water samples are collected from 2008 to 2015 at 17 stations in the Ying River basin in China. The two pollutants i.e. chemical oxygen demand (COD) and ammonia nitrogen (NH3-N) are analyzed to characterize the river water quality. Cluster analysis and the seasonal Kendall test are used to detect the seasonal and inter-annual variations in the dataset, while the Moran’s index is utilized to understand the spatial autocorrelation of the variables. The influence of natural factors such as hydrological regime, water temperature and etc., and anthropogenic activities with respect to land use and pollutant load are considered as driving factors to understand the water quality evolution. The results of cluster analysis present three groups according to the similarity in seasonal pattern of water quality. The trend analysis indicates an improvement in water quality during the dry seasons at most of the stations. Further, the spatial autocorrelation of water quality shows great difference between the dry and wet seasons due to sluices and dams regulation and local nonpoint source pollution. The seasonal variation in water quality is found associated with the climatic factors (hydrological and biochemical processes) and flow regulation. The analysis of land use indicates a good explanation for spatial distribution and seasonality of COD at the sub-catchment scale. Our results suggest that an integrated water quality measures including city sewage treatment, agricultural diffuse pollution control as well as joint scientific operations of river projects is needed for an effective water quality management in the Ying River basin.

Application of the public–private partnership model to urban sewage treatment

Funding shortages can greatly affect the construction and implementation of urban sewage treatment projects. Applying the public–private partnership model to urban sewage treatment projects will increase the financing capacity and mitigate the risk of local debt. Based on analyses of current urban sewage treatment projects and the relationship between the public–private partnership model and these projects, we demonstrated that the public–private partnership model is applicable to city sewage treatment projects, thereby enhancing social capital, improving the management and operation of the projects, and facilitating various management methods for innovation and optimization. We studied the relationships between responsibility and authority, benefit sharing, and risk sharing using the public–private partnership model as well as the main issues that affect urban sewage treatment, and we then analyzed these issues from the perspectives of government, enterprises, intermediary agencies, and public groups. We conclude that the implementation of public–private partnership models affects urban sewage treatment projects by defining the relationship between the government and market. Based on our comprehensive analysis, we provide policy suggestions regarding the public–private partnership model for urban sewage treatment with respect to government, social capital, and intermediary organizations, thereby providing a guide to the implementation of the public–private partnership model.

溧阳重点流域污染源解析研究

流域源解析可为水环境综合整治提供依据。本文采用调查和数学模型估算溧阳重点流域内点源和面源的典型水污染物的排放量和贡献率。结果显示，渔业养殖、种植农村生活污水和污水厂是溧阳主要的水污染源。工业排放的污染物虽然贡献率较小，但是从2011到2013有逐年增加的趋势。种植业的总氮、总磷排放量分别占溧阳排放总量的46.24%和46.88%。渔业养殖排放的COD、总磷分别占溧阳排放总量的26.01%和40.83%，且排放贡献率有增加的趋势。点污染源排放的COD、氨氮、总氮、总磷的贡献率分别为37.12%，44.02%，21.30%和7.63%，而面源的相应污染物的贡献率分别为62.88%，55.98%，78.70%和92.37%。对面源的管理控制措施是溧阳水环境整治的重点。 Source apportionment can provide the basis for comprehensive improvement of water environment. Based on the investigation and mathematical model, this paper estimated water pollutants emission and contribution from point source and non-point source in the key rivers of Liyang city. The results show that: the fishery, rural domestic sewage and city sewage treatment plant are the main water pollutant sources. The contribution of water pollutants from industrial emission source is small and the water pollutants emission from is increased from 2011 to 2013. The loss of the total nitrogen and total phosphorus from farmland accounted for 46.24% and 46.88% respectively. The loss of COD and total phosphorus from fishery accounted for 26.01% and 40.83% respectively and the pollutant contribution kept increasing. The contribution of COD, ammonia nitrogen, total nitrogen and total phosphorus from point source is 37.12%, 44.02%, 21.30% and 7.63%, and from non-point source is 62.88%, 55.98%, 78.70% and 92.37%, respectively. As a result, the management of non-point source is more important than that of point source.

태양광 발전량 예측 도구별 입력 요소 분석 및 실제 발전량 비교에 관한 연구

The objectives of this study are to investigate input variables of photovoltaic generation programs and to compare their prediction to actual generation of photovoltaic system in the C city hall and the C city sewage treatment plant. We investigated the actual amount of generation, the forecast amount of generation, the amount of solar radiation data, and calculated the relative errors. We simulated the photovoltaic system of C city hall and the C city sewage treatment plant located in Chungju using existing programs, such as SAM, RETSCREEN, HOMER, PV SYST, Solar Pro. The result of this study are as follows : Through examining the relative errors of monthly predicted and actual generation data, monthly generation data showed big errors in winter season?. Except winter season, actual amount of generation and the predicted amount of generation showed no large errors.

Assessment of Treating Laundry Wastewater Using Composites Based on Industrial Waste

For a long time, a large number of residential laundry wastewater emissions increased heavy burden to the city sewage treatment plant and brought serious pollution to the surface water. This study uses industrial waste (slag, fly ash) as substrate, mixed with some binder and pore forming agent to produce spherical composite materials for the study on adsorption of washing wastewater. Experiments show that the main pollutants of the laundry wastewater with sodium n-alkyl benzene sulfonate (LAS) are obviously removed.

Urban Sewage Treatment Process and Selection Principles

With the rapid development of modern society and economy, environmental problems have become increasingly prominent, especially the city water environment worsening, exacerbating the shortage of water resources, affecting people's physical and mental health, which has become the serious restriction factor of sustainable development of the city. This paper mainly discuss from the introduction of city sewage treatment technology and methods.

Research on Intelligent Control Integrated System of Water Treatment

This article analyzes, discusses the status of domestic water treatment and water treatment intelligent control systems, intelligent control of the water treatment system is deeply integrated, systematic research, the system successfully for a city sewage treatment.

The Hydraulic Optimization Design of High Specific Speed Axial Flow Pump for Sewage Treatment

With the development of the city sewage treatment, the request of the specific speed of axial flow pump has been higher and higher. At present China is lack of the system theory and method to design axial flow pump above 1400 specific speed. Selection methods of design parameters depend on experience. This paper used the improved lifting method to design axial flow pump. Optimize design of axial flow pump from cascade solidity, blade number, ratio hub and the airfoil of impeller. The feasibility of such optimize methods had been validated from theoretical analysis. Put forward new selection methods of design parameters. Design an impeller model. The rated condition of flow rate is 3000 m3/h and the rated condition of lift is 1 m. A useful reference of axial flow pump design, improvement and optimization was obtained.

Comparative Developmental Toxicity of New Aromatic Halogenated DBPs in a Chlorinated Saline Sewage Effluent to the Marine Polychaete Platynereis dumerilii

Using seawater for toilet flushing may introduce high levels of bromide and iodide into a city's sewage treatment works, and result in the formation of brominated and iodinated disinfection byproducts (DBPs) during chlorination to disinfect sewage effluents. In a previous study, the authors' group has detected the presence of many brominated DBPs and identified five new aromatic brominated DBPs in chlorinated saline sewage effluents. The presence of brominated DBPs in chlorinated saline effluents may pose adverse implications for marine ecology. In this study, besides the detection and identification of another seven new aromatic halogenated DBPs in a chlorinated saline sewage effluent, their developmental toxicity was evaluated using the marine polychaete Platynereis dumerilii. For comparison, the developmental toxicity of some commonly known halogenated DBPs was also examined. The rank order of the developmental toxicity of 20 halogenated DBPs was 2,5-dibromohydroquinone > 2,6-diiodo-4-nitrophenol ≥ 2,4,6-triiodophenol > 4-bromo-2-chlorophenol ≥ 4-bromophenol > 2,4-dibromophenol ≥ 2,6-dibromo-4-nitrophenol > 2-bromo-4-chlorophenol > 2,6-dichloro-4-nitrophenol > 2,4-dichlorophenol > 2,4,6-tribromophenol > 3,5-dibromo-4-hydroxybenzaldehyde > bromoform ≥ 2,4,6-trichlorophenol > 2,6-dibromophenol > 2,6-dichlorophenol > iodoacetic acid ≥ tribromoacetic acid > bromoacetic acid > chloroacetic acid. On the basis of developmental toxicity data, a quantitative structure-activity relationship (QSAR) was established. The QSAR involved two physical-chemical property descriptors (log P and pKa) and two electronic descriptors (the lowest unoccupied molecular orbital energy and the highest occupied molecular orbital energy) to indicate the transport, biouptake, and biointeraction of these DBPs. It can well predict the developmental toxicity of most of the DBPs tested.

The Automatic Control System Based on PROFIBUS for the City Sewage Treatment

On the basis of the computerized technological process control of sewage treatment in a urban sewage treatment plant in the Zone of Nanning, the author had brought forward a plan of PROFIBUS that based on automatic control system for sewage treatment, and designed the automatic control system diagram and the PROFIBUS network diagram for sewage treatment plant. At the same time, the author also made a study of techniques to control the sewage aeration, which was the most difficult problem in sewage treatment process. The fuzzy controller could indicate the changes of the water quality in treated sewage, effectively controlled the volume of aeration and then cut down the operation costs,it had produced good economic and social benefits.

Research on pH Value for City Sewage Optimized Control Based on HDP

During the city sewage treatment process, pH value has the nonlinear control characteristics of pure lag, large inertia and so on. This paper presents the adaptive system control method based on HDP (heuristic dynamic programming) in view of the above features. Three neural networks which are action, model and critic constitute a self-learning system for the approximate dynamic program the optimal performance index function to realize the optimized control on pH value. The emulation experiments show that this method has better control effects comparing with the traditional method PID on steady-state error, overshoot, response speed and anti-jamming ability.

Case study on pressured microfiltration and reverse osmosis membrane systems for water reuse

According to the announcement by OECD [1], Korea is listed as the most “severe water stress” nation among OECD countries. As competition for restricted water resources is expected in the coming decades, development of technologies for water treatment and reuse becomes urgently needed. The combined microfiltration (MF) and reverse osmosis (RO) process has been one of the mostly employed treatment methods in obtaining recyclable quality for wastewater reclamation and reuse, yet few has reported a pilot-scale investigation with the pressurized MF (without pretreatment) and RO system. The pilot plant operated in Gimcheon City Sewage Treatment Plant consists of a PVDF membrane in pressurized MF (treatment capacity of MF and RO: 30 and 20 m3/day) and a RO unit of wastewater reclamation. The result of the pilot study indicates that the reclaimed water can conform industrial water reuse standard (i.e., Turbidity (MF): 0.05 NTU, TDS (RO): 4.9 mg/L, TOC (RO): 0.79 mg/L). While the recovery rate run at the MF unit was 90%, the RO system was operated at 67%, to reach an overall system recovery rate of 60%. Herein, we report the performance of a pilot-scale pressurized MF and RO system operated for water reuse and discuss possible applications of the system for a test bed.

Analysis of some pharmaceuticals in municipal wastewater of Almadinah Almunawarah

The chemical pollution of water resources is a major challenge facing the humanity in this century. Pharmaceuticals and personal care products (PPCPs) are a group of emerging environmental chemical pollutants distinguished by their bioactivity and high solubility. They may also cause health complications to humans and living organisms. Pharmaceuticals enter the environment, mainly via wastewater and can eventually reach the surface and ground water. Despite this, PPCPs received less attention as environmental pollutants than other chemical pollutants (e.g. heavy metals and pesticides). The purpose of this work was to investigate the presence of some of the most frequently dispensed drugs for the residents of Almadinah Almunawarah, Saudi Arabia in the municipal wastewater before and after treatment. For this purpose, wastewater samples were collected biweekly from the city's sewage treatment plant for a period of 4months and analyzed the targeted drugs using tandem LC–MS. Out of the 19 investigated drugs, 5 pharmaceuticals have been found in concentrations greater than the limit of detection in both the influents and effluents of the sewage treatment plant. As expected, the concentrations of investigated pharmaceuticals in the wastewater were found to be low. These drugs and their average concentrations (in ngmL−1) in the influents were: acetaminophen (38.9), metformin (15.2), norfluoxetine (7.07), atenolol (2.04), and cephalexin (1.88). Meanwhile, the effluents contained slightly lower levels (in ngmL−1) than those of influents: acetaminophen (31.2), metformin (3.19), norfluoxetine (7.25), atenolol (0.545), and cephalexin (1.53). The results of this study supported by many other investigations indicate the inefficiency of current conventional wastewater treatment protocols in eliminating such a group of active and potentially hazardous pollutants from the wastewater.