Design and Operation of Municipal Rain and Sewage United Pumping Station

In the process of designing a municipal rainwater and sewage pumping station,it is necessary to accurately grasp the design points,reasonably determine the scale of the rainwater and sewage pumping station,scientifically select the location and layout,and select materials reasonably.After completing the process design of the municipal rainwater and sewage pumping station and putting it into operation,in order to ensure the normal and stable operation of the pumping station,it is necessary to focus on strengthening the operation and management of diving equipment,cleaning equipment,and electromechanical equipment.The author analyzes the key points and specific design path of the process design of municipal rainwater and sewage pumping stations,and puts forward effective strategies for operation management,hoping to contribute to the scientific design and stable operation of municipal rainwater and sewage pumping stations.

Analysis of Municipal Water Supply and Drainage Pipe Design Technology

The quality and safety of residents’water rely heavily on the design of municipal water supply and drainage pipes.Therefore,this paper aims to enhance the optimization of municipal water supply and drainage pipe design by focusing on design requirements,principles,and key elements.Drawing from relevant design optimization experiences,technology advancements,and optimization measures,the research will analyze and consolidate the essential aspects of municipal water supply and drainage pipe design.The goal is to fundamentally elevate the quality standards of these designs,ensuring they meet the criteria for engineering project excellence.Through this comprehensive approach,we aim to contribute to the improvement and sustainability of water supply and drainage systems,safeguarding the well-being of residents.

The Hydrochar Characters of Municipal Sewage Sludge Under Different Hydrothermal Temperatures and Durations

Innovative measure is a urgent requirement for managing the huge volume of municipal sewage sludge. The hydrothermal carbonation （HTC） shows some potential advantages for using hydrochar as a soil conditioner. The aim of this work was to investigate the properties of hydrochars, by means of the HTC of municipal sewage sludge under different temperatures （190 and 260~C） and reaction hours （1, 6, 12, 18 and 24 h）. The HTC led to the decreases of N, O and H contents by more than 54.6, 37.9 and 10.0%, respectively, and slight changes of C content. The Py-GC-MS analysis showed that a large proportion of fatty acids, in particular hexadecanoic acid, transferred into alkenes, olefins and aromatic compounds. The 13C-NMR and fourier transform infrared spectra （FTIR） confirmed the transformation and changes in chemical structure in which hydrochar contained lower oxygen-containing organic C of O-alkyl, carboxylic and carbonyl C and aliphaticity, but higher aromatic C and aromaticity. The rich hydrophobic functions induced in high positive charges in the charred sludge. The HTC facilitated the pore structure development, proved by higher specific surface area and specific pore volume, with a maximum of 17.30 and 0.83 cm^3 g^-1, respectively. The availabilities of N, P and K markedly reduced during HTC treatment. The activities of most heavy metals were depressed though they accumulated in the hydrochar. Further work is required to investigate the values and risk of the charred sludge amended to soil.

Long-term impact of municipal sewage irrigation on treated soil and black locust trees in a semi-arid suburban area of Iran

The effects of municipal sewage irrigation on the soil and black locust （Robinia pseudoacacia L.） tree were studied. For this purpose, two artificial black locust stands under irrigation of municipal sewage and well water were selected in south of Tehran, Iran. Data were collected using technique of systematic random sampling with 4 replicates in each stand. It was found that the growth of black locust tree, as indicated by diameter at breast height, total height, crown length, average crown diameter, basal area and volume, in sewage irrigation stand was much higher than that of well water irrigation stand （P 〈 0.01）. Plant analysis indicated that concentrations of leaf nutrients （N, E K, Ca, Mg, Na, Fe, Mn, Cu and Zn） were greater in sewage-irrigated trees, without toxicity to the minerals of tree leaf, than those of well waterirrigated trees, and positively correlated with their respective value in soil. Ni, Cr and Pb were not detected in leaf samples. Application of sewage resulted in a 1.5-fold increase in the concentrations of soil nutrients, Ni, Cr and Pb. Among these minerals only Pb and Ni in some soil samples exceeded the toxicity limit. The increase in pH, electrical conductivity （EC） and organic carbon of soil was also observed in sewage irrigation. Results confirm that besides the use as irrigation water, municipal sewages are also a potential source of plant nutrients. However, significant accumulation of heavy metals such as Pb and Ni in soil needs to be monitored.

Greenhouse gas emissions from a constructed wetland for municipal sewage treatment

The fluxes of greenhouse gases (methane and nitrous oxide) emission from a constructed wetland in the Eastern China as municipal sewage treatment were measured from June 1999 to August 2000 by the closed chamber method. The constructed wetland for municipal sewage treatment is a significant source of methane, up to 976 6×10 6 g CH 4/a, which was emitted from the constructed wetland with the area of 495000 m 2 and wastewater loading rate of 12000 m 3/d. Its daily mean methane flux reached 5 22 g CH 4/(m 2·d), 250 times as much as that in natural wetland in the same latitude region. 227 8 mg CH 4 was produced from the treatment of 1 liter wastewater, up to 700—1000 times as much as that in the secondary treatment. The emission of nitrous oxide from the constructed wetland is not higher than that from secondary treatment of wastewater, only 0 07 mgN 2O/L.

Effects of Municipal Sewage Sludge on Fixation of Cr,Ni,Cu,and Zn during Co-processing of Heavy Metal-containing Waste in Cement Kilns

Cement raw meal with MSS and different heavy metals was blended to examine the fixation ratios, chemical species, and cement crystalline phases in clinkers. The results showed that blending MSS could decrease the fixation ratio of Cr, Ni, Cu, and Zn in the produced clinker by 5% to 25%. And Cr, Cu, and Zn were mainly incorporated into clinkers as metal silicates, Ni was mainly solubilized in Mg O to form magnesium nickel oxides, and the transition phases were mainly metal aluminum oxides as indicated by X-ray diffraction. The reduction of fixation ratios was likely attributed to the presence of impure elements, such as sodium and phosphorus in MSS. In addition, high concentrations（eg, 1.7 wt%） of chlorine in MSS led to metal chloride formation that could vaporize Cu, Cr, Ni, and Zn. To summarize, introducing MSS would decrease the fixation ratios of heavy metals due to the presence of impure elements, such as sodium and phosphorus and chlorine.

Static aerobic composting of municipal sewage sludge with forced ventilation:Using matured compost as bulking conditioner

Static aerobic composting of municipal sewage sludge with forced ventilation or air ventilation using matured compost as bulking conditioner was investigated. Physical and chemical parame ,eters, e.g., temperature, moisture content, VSS, CODcr, pH, and germination index （GI）, were analyzed to characterize the composting process. Fermentation starts quickly in both forced and air ventilation compost heaps and reaches high-temperature stage after 2 d, owing to the bulking function of matured compost. Compared to air ventilation, however, forced ventilation enables the high-temperature stage to last longer for approximately 7 d. The moisture content of both compost bodies decreases from 62% to about 50% as a result of evaporation, and it decreases slightly faster in forced ventilation compost heap after 13 d due to the higher temperature and better ventilation condition. Although no obvious differences of VSS and pH are observed between both compost heaps, the soluble CODcr and GI show differences during the second half period of fermentation. In forced ventilation compost, the soluble CODcr has a small rebound after 13 d, and GI decreases from 46% to 35% but then increases. These results show that in general, the matured compost is a good conditioner and force ventilation with a proper air supply strategy can be more efficient than air ventilation.

The Physico-Chemical Quality of Effluents of Selected Sewage Treatment Plants Draining into River Rwizi, Mbarara Municipality, Uganda

As population increases in urban areas, the domestic and industrial activities increase resulting in an increase in the volumes of wastewater and anthropogenic pollution, hence posing a threat to public health and environment. This study assessed the physical chemical quality of two main sewage plant effluents discharging into River Rwizi. Effluent water samples were analyzed for dissolved oxygen, colour, turbidity, total suspended solid, total iron, phosphates, alkalinity, magnesium, calcium carbonate, temperature, pH, ammonium, electrical conductivity, chloride and nitrates. Parameters were analyzed following standard methods of APHA (1985). The values obtained were compared with EPA (2001), NWSC (2015) and NEMA (1999) standards for waste water. Results showed that the mean values most of the parameters tested were higher than the recommended EPA, NWSC and NEMA standards. The mean colour was 1627.67°C and 1414.33°C in Kakoba and Taso sewage effluents respectively compared to EPA (20-150), NWSC (500) and NEMA (300) standards (p > 0.05). The mean alkalinity was 1390.17 mg/l and 1308.33 mg/l for Kakoba and Taso respectively compared with EPA (400) and NWSC (800) standards. DO had a mean concentration of 68.27 mg/l and 63.03 mg/l in Taso and Kakoba respectively compared to EPA and NEMA standard of 5 mg/l. Mg was 243.29 mg/l and 246.49 mg/l in Kakoba and Taso sewage effluents respectively compared to NEMA standard for waste water of 100 mg/l (p > 0.05). The mean pH was 8.26 and 8.16 in Taso and Kakoba sewage effluents respectively compared to NWSC and NEMA standard of 6.0 - 8.0. Phosphate mean concentration levels were 32.2 mg/l and 27.11 mg/l for Taso and Kakoba respectively compared to standards of EPA (0.5 - 0.7 mg/l) and NEMA (10 mg/l). NO3 was 10 mg/l and 5.83 mg/l in Kakoba and Taso sewage effluents respectively compared to NWSC maximum permissible limit of 5 mg/l. The mean NH4 concentration was 385.33 mg/l (Kakoba) and 50.0 mg/l (Taso) compared to the EPA guideline range (0.2 - 4 mg/l). Chloride (Cl) had a mean of 833.33 mg/l in Kakoba compared to EPA (250 mg/l), NWSC and NEMA (500 mg/l) standards. Therefore the study recommends for effective treatment of waste effluents from Kakoba and Taso sewage treatment plants before recycling in order to avoid pollution of river Rwizi.

Removal of phosphate from municipal sewage by high gradient magnetic separation

The removal of phosphate from municipal sewage by high gradient magnetic separation using aluminium sulphate as precipitating agent and Fe3O4 as seeding material was studied. The effects of aluminium sulphate, Fe3O4, magnetic field intensity, pH value and flow-rate of sewage on phosphorus removal rate were investigated. The results show that addition of 200 mg/L Al2（SO4）3·18H2O and 300 mg/L Fe3O4, magnetic field intensity of 200 kA/m, pH value of 4.57.0 and flow-rate of 6.15 cm/s are both efficient and economic technical parameters for removal of phosphate. The pH value has a tremendous effect on the removal of phosphate. In the pH range of （4.5）7.0, more than 95% phosphate can be removed. Theoretical analysis indicates that the solubility of AlPO4 is minimum at pH 4.07.0 and the electrostatic attractive force between AlPO4 and Fe3O4 is maximum at pH 4.5（6.5.）

Utilization of coal fly ash and municipal sewage sludge in agriculture and for reconstruction of soils in disturbed lands： results of case studies from Greece and China

Coal fly ash （CFA） and municipal sewage sludge （MSS） management is a great concern worldwide. An alternative gaining high interest, is their use in agriculture and for reclamation of degraded lands. The purpose of this paper was to present very briefly the results of some case studies carried out in China and Greece related to land reclamation and agricultural use of CFA and MSS separately or combined. An experiment in Platanoulia area, central Greece showed clearly that CFA applied together with MSS at appropriate rates increased substantially wheat grain and biomass yield and improved soil quality （increased soil pH, organic matter content, total nitrogen, available P and boron）. In a long-term experiment carried out in Huaibei city, Anhui province, China with a reconstructed soil in a subsided land by using CFA, it was found that physicochemical characteristics （infiltration rate, bulk density, total nitrogen, available P and extractable K） tended to be improved over time. In another experiment in Rodia area central Greece, MSS application improved soil quality of limestone mining spoils from bauxite mining activities. Several other experiments with MSS in Greece showed a clear positive effect on cotton and maize yield and on soil quality.

Development of a novel modified EGSB reactor for municipal sewage treatment at ambient temperatures

A novel modified expanded granular sludge bed(EGSBm) reactor was developed for anaerobic treatment of municipal sewage with mixed liquid recirculation instead of effluent recirculation commonly adopted by a conventional EGSB(EGSBc) reactor.Performances of these two reactors were compared in treating municipal sewage at ambient temperatures ranging from 8 to 26 ℃.At an upflow liquid velocity(Vup) of 10.3 m/h,the mean concentrations of filtrated COD(CODfilt) and COD of the EGSBm effluent were determined to be 59.4 and 95.9 mg/L,respectively,which were significantly lower than those of the EGSBc effluent operated under identical experimental conditions.When the organic loading rate was suddenly increased from 1.2 to 7.2 kg COD/(m3·d),the EGSBm regained the removal efficiency of previous operation phase in 10 d.Hydrodynamic characteristics of the reactors were compared using the residence time distribution(RTD) model.It was found that the treatment efficiency of EGSBm kept increasing as the Vup increased.The polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis(PCR-DGGE) technique was used to analyze the microbial diversity in EGSBm.Fingerprinting pattern indicated that some species in the inoculating sludge were still reserved in the granular sludge of EGSBm,moreover,several new species occurred.

Kinetics of municipal sewage degradation in EGSB and UASB reactors at 10 ℃

Kinetics of municipal sewage degradation in Expanded Granular Sludge Bed(EGSB)and Up-flow Anaerobic Sludge Blanket(UASB)reactors at 10℃ were investigated via continuous experimental equipments.The results indicated that the whole reaction process can be simulated by the first-order dynamic equation model.Dynamic parameters such as k,Vmax and Ks of UASB in hydrolysis acidification stage were 1.08 d-1,2.8 d-1 and 372 mg/L comparing to those of 1.18 d-1,3.5 d-1 and 112 mg/L in the methanogenesis stage respectively.The EGSB’s k,Vmax and Ks were 2.91 d-1,14.3 d-1 and 470 mg/L in the hydrolysis acidification stage comparing to those of 1.68 d-1,6.6 d-1 and 103 mg/L in the methanogenesis stage respectively.Comparison of k values of the two stages in UASB and EGSB indicates that hydrolysis acidification stage is the controlling step for the whole reaction process of UASB,while methanogenesis stage is the controlling step in EGSB.Compared with UASB,municipal sewage treatment by EGSB at 10 ℃ can reach the same effluent requirement with lower retention time due to its effluent recirculation.

Research on Contribution ofPhosphate-based Detergent toMunicipal Sewage in Beijing

Based on the latest study of phosphate detergent ban and restrict, the phosphorus discharge from detergent in Beijing has been investigated. According to the status of wastewater treatment plants and its practical function, phosphate-based detergent's contribution to the municipal sewage is calculated to be 8.41%, which is less than the average (20% ) in most other cities of China.

CANON Process for Nitrogen Removal from Effluents of Municipal Sewage Treatment Plants

The feasibility and performance of nitrogen removal from municipal sewage were investigated through the completely autotrophic nitrogen removal over nitrite (CANON) process in a continuous reactor. CANON process was successfully started up with the transformation of nitrogen into gas by mass-balance analysis. For the synthetic waste-water (up to 480 mg NH4+-N/(L·d)), removal rates of the ammonia nitrogen and total nitrogen (TN) were about 80% and 55%, respectively, at 1.25 h hydraulic retention time (HRT). For the secondary effluent of municipal sewage, the effluent concentrations of NH4+-N and TN were below 5 mg/L and 9 mg/L, respectively. It is in accordance with the water quality standard for scenic environment with the reuse of urban recycling water (GB/T 18921-2002).

A preliminary study on total removal efficiency of organic pollutants in sewage by Harbin municipal sewage treatment plant

To evaluate the removal efficiency of organic pollutants in the sewage by Harbin municipal sewage treatment plant, the influent and effluent samples from the plant were pretreated by liquid-liquid extraction （LLE） under conditions of acidity, neutrality and alkaleseence in sequence, and then were analyzed by gas chromatograph-mass spectrum （GC-MS） procedures. Results indicate that there are 70 species of organic pollutants in the influent sample of the plant, which mainly consist of alkyls, benzene series, esters, and heteroeyclic compounds. Some of these organic pollutants are biotoxie and belong to persistent organic pollutants （POPs）. Four species among them are on the list of Prior Pollutants of Environmental Protection Agency of USA （USEPA）. However, 7 species of organic pollutants appearing in the effluent sample mainly include alkyls of multi-carbons and phthalate esters. The removal efficiency of phthalates is poor because of their poor biodegradability. The sewage treatment technique is effective in removing most＋of organics pollutants.

Phytoextraction of Nickel and Chrome in Paddy Soil Amended With Municipal Solid Waste and Sewage Sludge

A field study was conducted in the paddy soil amended with municipal solid waste （MSW） and sewage sludge （SS） to find out total, DTPA extractable nickel （Ni） and chrome （Cr） in soil and their uptake by rice plant as split-plot arrangement based on randomized complete block design with three replications. The results indicated that the most available Ni （2.10 ppm） measured under 3 years application of 40 ton.ha~ MSW＋I/2 chemical fertilizer （CF）. Also, with 3 application of 40 ton-ha＂l MSW concluded the highest available Cr. The most accumulation of Ni in root （14.51 ppm） and grain （8.89 ppm） happened under 3 years application of 40 ton.ha-1 SS and 20 ton ha-1 MSW＋I/2 CF, respectively. With application of 40 ton.ha-1 SS and 40 ton SS＋1/2 CF, respectively happened the maximum Cr uptake by root and grain （12.43 and 3.65 ppm, respectively）.

Low-carbon city communication:Integrated strategies for urban and rural municipalities in Thailand

As an important sustainable development goal,the creation of low-carbon cities(LCCs)has become crucial to creating livable cities and environmental sustainability.Thus,we aimed to understand the factors that support the transition of traditional cities to LCCs,by analyzing and synthesizing how to promote practical LCC across 15 pilot municipalities in four regions of Thailand,covering four strategies:City of Trees,City of Waste Minimization,City of Energy Efficiency,and City of Sustainable Consumption.Literature research,in-depth interviews,and observations were employed for data collection,while the 5​W(who,says what,in which channel,to whom,and with what effect)and SMCR(sender,message,channel,and receiver)models were used to create a communication analysis framework.Results revealed that the effective activities of municipalities should increase tree planting and implement more serious regulations for the conservation of existing trees.Making compost and establishing waste recycling banks are recommended for rural municipalities,while optimization of garbage and wastewater management systems and facilities should be highlighted in urban municipalities.Moreover,recycling,low-carbon agriculture,second-hand shops/markets,green markets,and homegrown vegetables should be encouraged for sustainable consumption.Working with local municipalities,credible leaders and representatives were the key senders.Additionally,message design should compare the pros and cons of behaviors,connect with local health and tourism,and promote dialogue in easy-to-understand and thought-provoking language.Receivers that drive LCC should have an excellent understanding of LCC practice and its benefits,be public-minded,and have a desire to live in a good environment.

Improved Denitrification of Municipal Sludge in Biofilm-electrode Reactor

The denitrification of municipal sludge was improved by combining biofilm process with the electro-chemical effect in a single novel reactor. Experiments in this reactor[electric current 60 mA, hydraulic retention time(HRTs) 6.0 h] showed that the removal of COD_ Cr, ammonia nitrogen and total nitrogen in the biofilm-electrode reactor were 2.5%, 1.2%, 14.9%, respectively, higher than those in a traditional biofilm reactor.

天津市市政污泥处理处置现状总结分析

市政污泥是污水处理的副产物,是污水处理过程的延续和必然要求。然而,如何实现低碳处理和资源化利用成为了当前重要的研究课题。本文对天津市市政污泥的产量现状进行了调研,概括总结并对比了现有污泥项目处理工艺、项目规模、处置现状等,最后展望了其资源化利用的新途径,以期为我国其他城市污泥处理处置工艺的选择提供一定的参考和借鉴。

长江大保护试点城市某污水处理厂尾水湿地净化效果研究

为探寻污水处理厂配套尾水湿地净化效果,以长江大保护试点城市某污水处理厂尾水湿地为例,通过现场调查与采样,分析湿地出水水质特征,探讨影响湿地污染物去除效率因素。结果表明:尾水湿地出水COD、NH_(3)-N及TP浓度满足设计目标,潜流湿地对COD去除率较高,表流湿地对氨氮及磷的去除率较高,优于涵养塘;湿地实际运行水力负荷、水力停留时间和污染物负荷与设计值不符,影响污染物去除效果;据此提出湿地运行优化建议,促进湿地深度脱氮除磷,提升尾水湿地效能;运行优化可提高潜流湿地污染物去除率,同时污水处理厂减少碳排放94.74 gCO_(2)m^(3)。研究结果可为该尾水湿地运行管理及长江大保护试点城市系列污水处理厂配套尾水湿地设计与运维提供参考。