•A hybrid NF/RO filtration scheme for nitrate removal is proposed and tested.•Production of low salinity brines allowed to be discharged to sewerage systems.•The new scheme can be applied in single ...or double NF stage modes prior to RO step.•Appropriate NF membranes for the process should reject Cl− better than NO3−.•The results show the process to be both technically feasible and energy efficient.
A novel and potentially cost effective filtration scheme for removal of nitrate from groundwater, characterized by production of low salinity waste brine that can be easily discharged to sewerage systems and high product-water recovery, is proposed. The inherent preference of particular NF membranes for rejecting chloride and sodium over nitrate ions is utilized in a preliminary NF stage to remove Na+, Cl+, Ca2+ and Mg2+ to a side stream. In a second stage, RO is applied to remove NO3− and the RO permeate is mixed with the side stream of the NF stage to create product water low in nitrate, yet with a balanced composition consisting all the required species and minerals. The number of NF stages depends mainly on the rejection efficiency of the NF membrane. Based on Israeli regulations for both drinking water and required composition of brines discharged to the sewage, a treatment scheme composed of a single and double NF stages followed by RO is shown to reach water recoveries of 91.6% and 94.3%, respectively. Each NF stage raises the energy cost by approximately 0.5cent/m3 product water. However, this cost is easily paid back by the inherent additional advantages of the combined scheme, i.e., less water treated by the RO, significant increase in total recovery ratio, no need in re-mineralization of the product water and minimization of calcium carbonate precipitation potential on the RO membrane. The principles for process design are described, making the specific treatment scheme proposed here easily adjustable to other regulatory requirements and other water characteristics. A provisional patent has been filed.
This study aims to show the development of sanitation and hygiene infrastructure in Bandung from the late 19th century to the early 20th century. This research positions sanitation and hygiene ...infrastructure as part of urban technology that contributes to public welfare. This research used the historical method which consisted of four stages: heuristics, critics, interpretation, and historiography. Results show that sanitation management in Bandung in the early 20th century was conducted by harmonizing technology and natural fortress. Gemeente Bandung anticipated the unhygienic habits of the villagers, environmental pollution, and spread of diseases by providing clean water, toilet facilities, public washing, and an integrated sewage system. The construction of infrastructure that supported sanitation management was carried out from 1910 to 1938. As a result, by 1938, Bandung had already had clean water reservoirs, clean water pipelines, open pipelines for rainwater disposal, closed pipelines for waste disposal, sewage treatment systems, waste treatment management, and road cleaning services.
Wastewater recycling is one of the criteria for continuous innovation at the campus level. Reclamation of water from the sewage system for gardening activities is one way to achieve this target at ...Universitas Pertamina. The aim of this study is to design and verify a water treatment unit from sewage to ready-to-use water for gardening activities. The units needed for the wastewater treatment system are a tank, Horizontal Roughing Filter (HRF), Rapid Sand Filtration (RSF), reservoir, and disinfection. The expected quality of effluent from processing is TDS 278 mg/L; TSS 1.3 mg/L; Turbidity 0.17 NTU; BOD5 0.63 mg/L; COD 6.12 mg/L; Total phosphate 0.95 mg/L; Nitrate 0.07 mg/L; detergent 0.7 mg/L; and total coliform MPN/100mL. The most important parameter in the sewerage water treatment process is the total coliform which must achieve an efficiency of 99%. This conventional method of water treatment is used because the availability of land is still sufficient, if it is not sufficient then further processing that is efficient, environmentally friendly, and has economic value is required.
The main purpose of this work is to provide calculations of annual weight of sediment formation deposit in Municipal Collector System (MCS). The article considers two-phases flow in the collector. ...The storm water collector is small culvert for storm water (rainwater) or for removing the river (creek, stream, flow) underground. The article defines the solid particles in flow as sand, clay, stones, silt, etc. It was found that in case of signif\icant flow rate, then all solid particles move in the pipe. If not, they settle to the bottom and sediment is formed. In this paper, total weight of sediment formation in Moscow collector system is calculated at average annual values. On this ground a consideration can be made that sediment deposit reduces efficiency of the system partially or completely.
This article focuses on socio-technical changes in the current context of climate changes: in particular, it examines regulations' role in accomplishing those changes. For this reason, it focuses on ...the regulations implemented to protect aquatic environments in France through the analysis of the self-monitoring procedure for sewerage systems. Thus, this article is based on a study of the legislative and regulatory texts instituting this procedure and is also based on two case studies on the Metropolis of Lyon and Nantes. These cases include in situ observations and interviews with actors involved in the monitoring of sewage networks. They point out the effects of regulations on organizations and on the surveillance implementation of wastewater system discharges into aquatic environments by local authorities. However, monitoring remains limited due to the restricted resources (particularly in terms of personnel) of the local authorities and of the other involved organizations; its sustainability even appears fragile in Nantes’ agglomeration. Under these conditions, monitoring generally fulfills the minimum requirements of regulations (producing data on wastewater system discharges into aquatic environments), but does not meet the environmental objectives that originally led to the procedure (protecting the environment, restoring the quality of aquatic environments).
Though urban sewer is an important CH4 emission source, it is impractical to assess overall CH4 emission from massive and closed underground sewer networks through either online or off-line ...measurements owing to the complexity in construction and operation of sewer systems and highly variable wastewater quality. Here, we develop a feasible method based on emission factors and official statistical data for overall CH4 estimation from sewers. By using this method, we show that the CH4 emissions from sewers in China was 0.6185 Tg in 2019 and the national mean of the per capita CH4 emission from sewers was 1361 g cap-1. We find that temperature significantly correlates with sewer CH4 emissions specified with population or sewage quantity. We further argue that economic growth and urban infrastructure management also affect the CH4 emissions from sewers or surface waters due to sewage leakage/discharge. Our proposed method is practical for the sewer CH4 estimation worldwide.
•A feasible method for overall CH4 estimations from sewer systems was developed.•Complex structure and highly variable conditions in sewers are avoided with this method.•CH4 emissions from sewers in China was 0.6185 Tg in 2019.•The national mean of the per capita CH4 emission from sewers was 1361 g cap−1.
The main difference between rural and urban area inundation is the existence of an impermeable layer and the complexity of the road and building configuration. Therefore, although surface overland ...flow can be appropriately simulated by the two‐dimensional diffusive model in a rural area, there also is a need for a more accurate and elaborate simulation model. Dual drainage concept has been popular to simulate urban drainage system. Although the concept has immense advantages, through which overland flow and pipe flow can be simulated simultaneously, many researchers set manholes as discharge exchange spots between ground surface and sewerage system, which causes lack of reality. Therefore, in this study, we developed a new urban inundation model that can reflect real field situation. Also, two kinds of simulations are carried out with homogeneous meshes and non‐homogeneous ones using manholes and storm drains as discharge exchange spots, respectively, and those results are compared to estimate the effect of road networks and building groups according to different discharge exchange spots. Two‐dimensional run‐off flow model and one‐dimensional slot‐model are used to simulate ground surface run‐off flow and sewer pipe flow. To connect both models, we used a newly suggested bi‐directional model and its coefficients. The simulated results showed that more reasonable results are obtained in the nonhomogeneous case; the results further reveal the importance of using storm drains as exchange spots in the model.
The importance of manhole in the sewerage system is to get the underground pipelines and alternative systems area unit in good shape. A manhole cover is a detachable plate setting the roof above the ...manhole opening, to prevent anything from dropping in, and to stay away from unauthorized persons and matter to fall in it. Manhole covers are usually manufactured of cast iron, concrete or combine both. This creates them economical, powerful, and dense, generally weighing more than 50 kg. The weight supports to maintain them in position when transportation moves across them and makes it complicated for an unauthorized person not having proper tools to remove them. The traditional method of removing the manhole with the assistance of the hook. So, to safely remove the manhole cover, many innovative and automated techniques are designed and used for analysis. In this paper, the finite element analysis of a power screw operated manhole cover is analyzed with the help of ANSYS R14.5.
Analysis efficiency operating drain sewer systems (DSS) is a part of urban water management. Two basic parameters flooding and sediment formation with average annual precipitation and with rains ...varying intensity are considering. Dealing with hydraulic problems, modelling focus lies on non-pressure systems with two-phase flows. The main requirement in the design of gravity collectors is the flow rate with self-cleaning velocity. The initial data for hydraulics calculation DSS is the flow rate in hole system and geometrical characteristic of the each elements. The average velocity in local tube depends on average flow rate and the cross-sectional area. For calculation, cross-section area needs to estimate depth of flow, which can be find only in situ. The average velocity was found for each element of the system by combining the two matrices. The first contains the initial data of the working collector, and the second contains all possible velocities and depth of the collector with such geometric characteristics. Verification of the proposed model was carried out using data from the standards and from engineering systems in Moscow. Maps with the coordinates of the tube outlet in the considered part of Moscow where the flooded collectors and collectors with sediment were compiled.
The study provides a comparative analysis of the quality of sewage discharged from selected sewerage systems. The analyzed data were collected from 10 agglomeration sewerage systems discharging ...sewage into collective wastewater treatment plants (WTP). The investigated pollution indicators included BOD
, COD
, total suspended solids and biogenic indicators such as total nitrogen and total phosphorus. These results were compared with the outcomes reported in commonly available research papers on sewage disposal. Considering the concentration of individual pollution indicators, more detailed categories of sewage pollution were adopted in this work. The sewage was divided into five basic groups: I – highly concentrated, II – concentrated, III – moderately concentrated, IV – diluted, and V – highly diluted. The sewage categories accounted for the following pollution indicators: BOD
, COD
, total suspended solids, total phosphorus and total nitrogen. Mean BOD
, COD
and total suspended solids in raw sewage were higher than average values reported in the referenced literature. Contrary to that, concentration of total phosphorus in raw sewage was significantly lower than reported by other authors. The outcomes of this study suggest that the predictions concerning pollution degree of raw sewage made at WTP design stage should not be based exclusively on general values provided in literature reports.
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