Modeling spatiotemporal domestic wastewater variability: Implications for measuring treatment efficiency

The present study has been undertaken to evaluate performance efficiency of wastewater treatment plants (WWTPs) in El-Fayoum Markaz, El-Fayoum governorate in Egypt. The wastewater treatment plants using different treatment techniques were Active sludge, Oxidation ponds, Secondary - active sludge and Chemical (nanotechnology) which wastewater samples were collected from both influent and effluent of each plant. The key performance of each plant is estimated based on the treated wastewater quality data. Based on the results, they showed that Old Quhafa (Secondary - active sludge technology) operates with removal efficiencies higher than 80% for biological oxygen demand (BOD), chemical oxygen demand (COD) and total suspended solids (TSS) were established. While Ezbet Ashour accomplished lowest performance efficiency that operates with chemical-nanotechnology. This analysis applied to define a performance measuring plan based on the most important parameters that can be reliable and applicable for any WWTP. The study suggested formula for performance WWTPs that described by the expressing removal efficiencies as relative values or percentages and the remaining fraction. The study recommended that sedimentation units must be cleaned, monitoring frequently of sludge analysis and calculation of building capacity for all WWTPs.

With the rapid economic development, water pollution has become a major concern in China. Understanding the spatial variation of urban wastewater discharge and measuring the efficiency of wastewater treatment plants are prerequisites for rationally designing schemes and infrastructures to control water pollution. Based on the input and output urban wastewater treatment data of the 31 provinces of mainland China for the period 2011–2015, the spatial variation of urban water pollution and the efficiency of wastewater treatment plants were measured and mapped. The exploratory spatial data analysis (ESDA) model and super-efficiency data envelopment analysis (DEA) combined Malmquist index were used to achieve this goal. The following insight was obtained from the results. (1) The intensity of urban wastewater discharge increased, and the urban wastewater discharge showed a spatial agglomeration trend for the period 2011 to 2015. (2) The average inefficiency of wastewater treatment plants (WWTPs) for the study period was 39.2%. The plants’ efficiencies worsened from the eastern to western parts of the country. (3) The main reasons for the low efficiency were the lack of technological upgrade and scale-up. The technological upgrade rate was −4.8%, while the scale efficiency increases as a result of scaling up was −0.2%. Therefore, to improve the wastewater treatment efficiency of the country, the provinces should work together to increase capital investment and technological advancement.

Pakistan being an agricultural country greatly depends on the water. Intense agriculture and ever-increasing population growth have created stress on the limited water resources of the country. Therefore, use of industrial discharge effluent and sewage water for irrigation is a common practice. Realizing the situation of safe disposal of wastewater in Pattoki to minimize the public risks of indiscriminate disposal of wastewater, Punjab government and Korea International Cooperation Agency (KOICA) constructed a wastewater treatment plant at Pattoki district Kasur. The purpose of this study is to check the efficiency of wastewater being treated by the treatment plant in compliance with the National Environmental Quality Standards (NEQS) and to check the efficiency of functional components of treatment plant. Water samples were collected from various points of the treatment plant in order to perform various onsite and laboratory test (DO, BOD5, COD, Chloride, TSS, and PH) to check the efficiency of the wastewater treatment plant. The results obtained for each water quality parameters (physical, chemical, and biological) were compared with National Environmental Quality Standards (NEQS). The recommended value of DO was greater than 2 mg/liter, BOD5, COD, Chlorides, TSS and PH by PEQS were less than 80 mg/liter, 150 mg/liter, 1000 mg/liter, 150 mg/liter and 6.5-9 respectively. The measured values of DO, BOD5, COD, Chlorides, TSS and PH were 0.3 mg/liter, 310 mg/liter, 48 mg/liter, 1760 mg/liter, 204 mg/liter and 8.3 respectively. The values of DO, BOD5 and TSS are not within PEQS recommended range. More facultative and anaerobic ponds should be constructed in order to treat total wastewater generated in Pattoki, as present plant is treating almost one fourth of total wastewater generated in Pattoki. Aerators should be provided at the aerobic ponds for improving the efficiency of wastewater treatment plant. Effluent from the treatment plant can be used for floriculture conjunctively with fresh water. Moreover, the concentration of physio-chemical parameters in the effluent also decreases after mixing the water available in drain. To some extent it also reduces the infiltration of dangerous components (as drain is not lined with concrete) present in wastewater that may contaminate the ground water or may have hazardous effects on quality of soil present in field. However, further studies are required to evaluate chemical parameters or heavy metals like arsenic, fluorides, chromium, zinc etc.

Biological oxygen demand (BOD5) or chemical oxygen demand (COD) analysis is widely used to evaluate organic pollutants in water systems as well as the efficiency of wastewater treatment plants. However, both analysis methods have restrictions such as being insensitive, imprecise, time-consuming, and the production of chemical waste. Therefore, total organic carbon (TOC) analysis for organic pollutants has been considered for an alternative analysis instead of BOD5 or COD. Several studies have investigated the replacement of BOD5 or COD with TOC in wastewater samples; however, few studies have investigated the relationships between water quality parameters in rivers and lakes. Therefore, this study evaluated the relationships between BOD5, COD, or NBOPs and TOC by the analysis of national water quality monitoring data of rivers and lakes for 5 years. High correlation coefficients (r) of 0.87 and 0.66 between BOD5 and TOC (p < 0.05) were obtained for rivers and lakes, respectively, and strong correlation coefficients (r) of 0.93 and 0.75 were observed between COD and TOC (p < 0.05) for rivers and lakes, respectively. The correlation coefficient (r) between NBOPs and TOC was 0.93 for rivers and 0.72 for lakes. The coefficients of determination (R 2) were 0.75 and 0.44 between BOD5 and TOC for rivers and lakes as well as were 0.87 and 0.57 between COD and TOC for rivers and lakes, respectively. The coefficient of determination (R 2) between NBOPs and TOC was 0.73 for rivers and 0.52 for lakes.

High-performance Multi-stage Baffled A2O Treatment Process for Domestic Sewage on Plateaus

The efficiency of the poultry wastewater treatment plant of Zartech Limited, Ibadan, Nigeria, was assessed based on percentage reduction of the various water contaminants while the unit cost of treated water was compared with that supplied through tankers. Wastewater and treated water samples were respectively collected from the points of generation and release after treatment for laboratory analysis for biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), oil and grease, nitrate, phosphate and pH. The values for BOD, COD, TSS, oil and grease, nitrate and phosphate obtained for the wastewater were 1680, 5199, 7125, 1266, 70.0 and 6.8 mg/l, as against 22.8, 15.6, 0, 15.2, 0 and 0 mg/l, respectively, for the treated water. This translates to treatment efficiencies in percentages of 98.7, 99.7, 100.0, 98.8, 100.0 and 100.0 for BOD, COD, TSS, oil and grease, nitrate and phosphate, respectively. The pH of the wastewater was 6.7 as against 7.2 for the treated water. Based on the results obtained, the plant was adjudged efficient for the treatment of poultry wastewater. The cost of treated water was ₦0.18/l compared with ₦0.50/l for that supplied through tankers, resulting in a daily savings of about ₦120,506.95. Further cost reduction can be achieved through adjustment of dozing pumps. Key words: Pollution, poultry, slaughter house, treatment, wastewater.

The environmental impacts from energy consumption account for a high percentage of the environmental impacts of wastewater treatment plants (WWTPs) throughout their life cycle; therefore, controlling energy use in WWTPs could bring substantial benefits to the environment. In this study, according to the different percentages of electricity generation from renewable energy compared to fossil energy, the global warming, acidification, eutrophication, human toxicity, and photochemical smog, the environmental impacts of WWTP operation were considered. Furthermore, to explore a more sustainable way of operating WWTPs under the “dual-carbon” strategic decision, the environmental impacts and energy utilization efficiency of different power allocation scenarios at present and in the next 40 years were compared based on the LCA+DEA integrated model. The study revealed that in scenarios 1–5, as the proportion of renewable energy power generation gradually increased, all LCA results showed a gradual decrease, of which GWP decreased by 83.32% and human toxicity decreased by 93.34%. However, in scenarios 2–5, the contribution ratio (proportion) of gas and electricity to GWP and POCP gradually increased, reaching 77.11% and 59.44%, respectively, in scenario 5. The contribution ratio (proportion) of biomass generation to AP and EP gradually increased as well, reaching 65.22% and 68.75%, respectively, in scenario 5. Meanwhile, the combined technical efficiency in energy utilization in the five scenarios showed a decreasing trend; only scenario 1 was fully efficient, and the combined efficiency was 1. The values of combined technical efficiency in scenarios 2, 3, 4, and 5 gradually decreased and were 0.7386, 0.4771, 0.2967, and 0.1673, respectively. This study discusses whether the use of renewable energy in place of fossil energy power elicits an environmental impact in WWTPs. We explore the feasibility of achieving energy savings and emission reductions in WWTPs within the Tumen River Basin, to provide a theoretical basis for their sustainable development.

Control technologies of wastewater treatment plants: The state-of-the-art, current challenges, and future directions

This study was conducted at I-9 treatment plant, Islamabad to analyze the physicochemical assessment of various parameters and heavy metals concentrations in wastewater and to check the wastewater treatment plant efficiency. Therefore composite wastewater samples were collected from influent, effluent and external streams. Their results were compared with Maximum permissible limits (MPL) of Pakistan Environmental Protection Agency (Pak-EPA). The results of influent, effluent and external stream of wastewater samples are: pH ranged from 6.2 to 6.9, 6.4 to 6.9 and 6.8, EC ranged from 840 to 1250, 830 to 930 and 700 to 890 (μS/cm), Total dissolved solids ranged from 570 to 850, 570 to 630 and 480 to 600 mg/l, total suspended solids ranged from 0.062 to 0.09, 0.008 to 0.42 and 0.068 to 0.069 mg/l, Fluoride ranged from 0.4 to 4.7, 0.8 to 3.5, 1.2 to 2.9 mg/l, Chloride ranged from 48 to 180, 56 to 71 and 44 to 55 mg/l, respectively. Heavy metal concentrations were analyzed by using Atomic Absorption Spectroscopy (AAS) and were found that iron ranged from 0.16 to 2.94, 0.75 to 2.055 and 2.673 to 3.374 mg/l and manganese ranged from 0.193 to 0.579, 0.1 to 0.861 and 0.407 to 0.85 mg/l. Similarly, zinc ranged from 1.9 to 2.7, 1.8 to 2.5 and 2.3 to 2.8 mg/l and Ni ranged from 1.19 to 1.66, 1.15 to 1.56 and 1.11 to 1.21 mg/l. Likewise, lead ranged from 0.32 to 0.6, 0.15 to 0.65 and 1.1 to 1.2 mg/l, chromium ranged from 1.04 to 1.1, 1.06 to 1.11 and 1.1 to 1.11 mg/l, cadmium ranged from 0.2 to 0.4, 0.13 to 0.38 and 0.3 to 0.8 mg/l, respectively. Results of some parameters like nickel, lead, chromium and cadmium were found above the permissible limits of Pak-EPA. So it is recommended that Waste water should be treated at industrial territory. Only treated water should be allowed to drain into Lai stream.

Wastewater treatment plant (WWTP) is a sustainable technique for making wastewater reusable for non-potable purposes. However, in developing countries, most conventional WWTPs are not equipped to trap all pharmaceutical residues (PRs) and pharmaceutically active chemicals (PhACs). This study aims to perform non-target screening of these contaminants in wastewater and explore health and environmental hazards and the removal efficiency of a WWTP in Malaysia. At Indah Water WWTP, a total of 28 wastewater samples (i.e., 2 L each of 14 influent and 14 effluent) were collected every day for a week from February to April 2023. The supernatant of the centrifuged sample was analyzed with the LCMS-QTOF system. Chromatographic profiles were analyzed, and the compounds were annotated using the METLIN database. Categorical data were statistically analyzed with SPSS 29.0 using a chi-square test and continuous variables using paired t-test and multiple regression. PRs like micronutrient (9, 2.3%) and PhACs like lipid (83, 20.8%) were more frequent. Detection frequencies of PRs and PhACs were 72 (18%) and 328 (82%), respectively. Efficiency of WWTP was 36.4 to 100% for PRs removal (mean ± SD: 65.85 ± 56.43%) and 20 to 100% for PhACs removal (mean ± SD: 49.30 ± 55.94%). A total of 943 (mean ± SD: 67.36 ± 43.28) and 400 (mean ± SD: 28.57 ± 32.44) unique PRs and PhACs were recorded. A total of 40 (10%) PRs and PhACs had the potential to irritate eyes, skin, and respiratory tract, and 46 (11.5%) chemicals needed to be avoided from being discharged into the environment. Though WWTP was 98.0% compliant with environmental standards, its efficiency should still be increased to remove the full range of PRs and PhACs. The research has implications for SDGs 6 and 14.

A comprehensive assessment of energy efficiency of wastewater treatment plants: An efficiency analysis tree approach

The application of partial nitritation and anammox processes (PN/A) to remove nitrogen can improve the energy efficiency of wastewater treatment plants (WWTPs) as well as diminish their operational costs. However, there are still several limitations that are preventing the widespread application of PN/A processes in urban WWTPs such as: (a) the loss of performance stability of the PN/A units operated at the sludge line, when the sludge is thermally pretreated to increase biogas production; (b) the proliferation of nitrite-oxidizing bacteria (NOB) in the mainstream; and (c) the maintenance of a suitable effluent quality in the mainstream. In this work, different operational strategies to overcome these limitations were modelled and analyzed. In WWTPs whose sludge is thermically hydrolyzed, the implementation of an anerobic treatment before the PN/A unit is the best alternative, from an economic point of view, to maintain the stable performance of this unit. In order to apply the PN/A process in the mainstream, the growth of ammonia-oxidizing bacteria (AOB) should be promoted in the sludge line by supplying extra sludge to the anaerobic digesters. The AOB generated would be applied to the water line to partially oxidize ammonia, and the anammox process would then be carried out. Excess nitrate generated by anammox bacteria and/or NOB can be removed by recycling a fraction of the WWTP effluent to the biological reactor to promote its denitrification.

The present study evaluates the performance efficiency of a wastewater treatment plant. A sewage treatment plant operating on biological treatment method (Rotating Media Bio-Reactor) with an average wastewater inflow of 6 MLD has been considered for the case study. Wastewater samples were collected at different stages of treatment units and analyzed for the major waste water quality parameters such as biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), and biodegradability. The performance efficiency of waste water treatment plant along with the major secondary treatment unit as Rotating Media Bio-Reactor (RMBR) was calculated. The performance analysis on above two aspects was studied over 17 weeks. Overall performance was found to meet the design and discharge/effluent criteria as prescribed by the authorities. The studies of six units of Rotating Media Bio-Reactor (RMBR) over a period of 13 weeks have shown the reduction profile of the unit in treatment of wastewater with parameters of BOD and COD. The RMBR treatment profile is useful for the design and operation of the unit.

Abstract. The stable isotopic composition of precipitation (δ2HP, δ18OP; “water isotopes”) is a powerful tool for tracking water through the atmosphere, as well as fingerprinting land-surface water masses and identifying water cycle biases in isotope-enabled climate models. Water isotopes also underpin our understanding of multi-decadal to multi-centennial water cycle variability via their retrieval from palaeoclimate archives. Water isotopes thereby increase our understanding of past and present – and hence future – water cycle variability. Understanding the drivers of spatial and temporal water isotope variability is a critical first step in applying these tracers for a better understanding of the water cycle. However, water isotope observations are sparse in both space and time. Here we develop and apply a machine learning (random forest) approach to predict spatially continuous monthly δ2HP and δ18OP across the Australian continent at 0.25° resolution from 1962–2023. We train the random forest models on monthly δ2HP (n=5199) and δ18OP (n=5217) observations from 60 sites across Australia. We also predict the deuterium excess of precipitation (dxsP, defined as δ2HP-8×δ18OP). Out-of-sample δ2HP and δ18OP prediction skill is high both geographically and temporally. Skill is slightly lower for the secondary parameter dxsP, likely reflecting the larger reliance of spatio-temporal dxsP variability on moisture source conditions. The random forest models accurately capture both the seasonal cycle of precipitation isotopic variability and long-term annual-mean precipitation isotopic variability across the continent, and outperform estimates from an isotope-enabled atmosphere general circulation model over an equivalent time period. We show that spatio-temporal variability in precipitation amount, precipitation intensity, and surface temperature are particularly important for monthly δ2HP and δ18OP variations across the continent, with local surface pressure also important for dxsP. Drivers of site-level δ2HP, δ18OP, and dxsP are more varied. Overall, the new random forest modelled dataset reveals clear spatial and temporal variability in δ2HP, δ18OP, and dxsP across the Australian continent over the past decades – providing a robust foundation for hydrology, ecology, and palaeoclimate research, as well as an accessible framework for predicting water isotope values in other locations.

In this paper, we propose the design and construction of Broadband Convergence Network(BcN) with WiFi and ZigBee combination to transmit sensor data in smart water grid. We collected sensor data to a broadband modem using ZigBee communication for integrated management server to transmit the sensor data values ​​used in the wastewater treatment plant. And then, we were built the system that transmitted collected sensor data real-time to the integration management server through WiFi communication. BcN with broadband modem improves the control capabilities the existing wastewater treatment plant. It is an efficient energy management is possible. Therefore, contribute to improve the energy efficiency of wastewater treatment plant is expected.