Design Of Wastewater Treatment Plants Research Articles

Synthesis of a Sustainable Wastewater Treatment Plant for Sago Industry using Fuzzy Optimisation

Wastewater treatment plant (WWTP) is an essential process in the manufacturing industry. However, wastewater treatment process is not a profitable process as it requires a significant amount of investment. It is important to design a WWTP that meets wastewater discharge legalisation with low investment costs. To do this, area footprint (land area) occupied by technologies in a WWTP must be factored into the design decision. Unfortunately, the area footprint is yet to be studied. As wastewater treatment processes involve multiple treatment units, the different combinations of these treatment units will give a range of capital costs and costs associated with the area occupied. In addition, the carbon footprint of technology resulting from power consumption must be considered. Each technology possesses unique power consumption requirements and these requirements may influence the total carbon footprint for a given WWTP design. Investment costs, area footprint and carbon footprint must be considered simultaneously but are conflicting in nature. This work aims to present a multi-objective decision-making tool to screen wastewater treatment technologies and to synthesise a WWTP design with low investment cost, low area footprint, and low carbon footprint. Specifically, fuzzy multi-objective optimisation (FMOO) is used to determine a desirable trade-off between investment costs, area footprint, and carbon footprint. To demonstrate the developed approach, a sago-based WWTP case study is solved. Based on the results, a trade-off between these optimisation objectives had reduced 5.35 m2 of area footprint, 986 USD/d of total investment cost, and 108 kg CO2/d of carbon footprint of the synthesised WWTP.

Physicochemical assessment of urban wastewater of Cotonou (Benin).

The present study aims to fill the data gap analysis in urban wastewaters characteristics in Benin and its statistical analysis. Physicochemical parameters such as pH, electrical conductivity (EC), Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD5), Total Kjeldahl Nitrogen (TKN), Total Phosphorus (TP) and UV Absorbance at 254 nm, were determined on domestic (greywater and blackwater) and industrial (hospital, pharmaceutical and commercial laundry) wastewater in Cotonou city. Analysis of variance showed a strong significant difference in the physico-chemistry of the various effluents. The pharmaceutical wastewater has the highest concentration of organic pollution (COD = 5,912 ± 1,026 mg/L, Abs.UV254 = 2.667 ± 0.327 cm-1). The organic load of blackwater is mainly in particulate and biodegradable form. Besides, the correlation study showed the limits of pH and EC as an indicator of organic load. Furthermore, the choice of COD or BOD5 as the main design parameter would be limited to blackwater treatment. Abs.UV254 was found to be the parameter having a strong relationship with other parameters of all effluents except blackwater. It then takes priority over COD for the treatment of greywater and industrial wastewater. For future wastewater treatment plant design, we recommend to consider Abs.UV254 as an important parameter.

Design for Wastewater Treatment Plants (WWTP) for Cattle in a Single House Model with a Bio Filter Process

Liquid waste generated from cattle farms is discharged directly into culvert and river. The liquid waste is not treated so it has high potential to threaten and pollute the water and ground water environment. With the average flushing done twice a day, the gross amount of wastewater that is wasted is not less than 100-150 liters/day/cattle for weight 400 kg (Saputro et al. 2014). Therefore a wastewater treatment plant (WWTP) is needed to control the massive liquid waste. In addition, WWTP must be simple, inexpensive, and appropriate so that the community can apply it. Data collection is needed, namely data on the number of cattle livestock, waste water quality data and waste water discharge data. The organic parameters of cattle waste that are considered are BOD, COD, TSS, NH3-N, and pH only (Regulation of the State Minister for the Environment Number 11 Year 2009 concerning Wastewater Quality Standards for Cattle and Pork Businesses and/or Activities). Design for wastewater treatment plants (WWTP) model using the MSL (Multi Soil Layering) method (Alternative 1) and the combination of MSL with anaerobic wasps nest biofilter (Alternative 2) (Said et al. 2001). Compare the effluent results in the both alternatives that available the quality standards and analyze more optimally.

The impact of sludge return liquors on South African wastewater treatment plants

There have been three considerable shifts, in the past 20 years, in the conventional design and modelling of wastewater treatment plants (WWTPs): (i) single unit process to plant-wide modelling, (ii) consideration of WWTPs as water and resource recovery facilities (WRRFs), and (iii) the need to simplify WWTP models to allow their intake by new stakeholders (i.e. plant operators, designers and decision-makers) who use these models for evaluation of WWTP optimisation strategies. The latter shift has prompted the debate about model complexity versus the required modelling purpose among modellers. In addition to the aforementioned shifts, there has been limited research on the impact of sludge recycling dewatering liquor on the overall plant performance, especially in the context of South African WWTPs. A simplified full-scale steady-state WWTP simulation tool was developed, based on principles of sound mass-balance stoichiometry and rate-limiting kinetics. This tool enables the user to analyse the impact of recycling the DWL on the plant performance through different scenarios. The strategic scenarios evaluated included the implementation of two side-stream treatment processes (STPs), namely BABE and struvite precipitation. The evaluation of various strategies was done using the benchmark simulation model (BSM) task group plant performance indices (i.e. effluent quality and operational cost indices, EQI and OCI, respectively) incorporated into the simplified steady-state full-scale models. The integration of STP in the WWTP layout results in better EQI and OCI. The composition of the DWL affects the choice of the STP to be used, i.e., for DWL from an AD treating WAS that is not P-rich the recommended side-stream treatment operation would be the BABE process rather than struvite precipitation.

Cost coupled removal efficiency analyses of activated sludge technologies to achieve the cost-effective wastewater treatment system in the meat processing units

This study was conducted to distinguish the most cost-effective activated sludge-based wastewater treatment technology by focusing on removal efficiency (RE) for applying in the meat processing units. Four different wastewater treatment plants (WWTPs), namely anaerobic/anoxic/oxic (A2O), membrane bioreactor (MBR), moving bed bioreactor (MBBR), and integrated fixed-film activated sludge (IFAS) were simulated regarding the daily annual data obtained from a meat processing unit. The descending order concerning the total cost (TC) was as follows: MBR > A2O > IFAS > MBBR while it was as MBR > IFAS > MBBR > A2O based on RE. Regarding the energy and material consumption costs, the A2O and MBR were the highest and lowest cost-effective systems, respectively. However, the MBR was the best from a biological treatment cost perspective. The boilers and co-generators contributed to 75% and 25% of the produced biogas, respectively, that supplied 50% of WWTP electricity demand. Among all different influent parameters, the effect of flow rate, COD, and BOD on the TC was statistically significant. Furthermore, the TC and present worth illustrated the most sensitivity to the construction cost alteration. This research provides insights into key economic parameters for a WWTP design and application.

Wastewater COD characterization: RBCOD and SBCOD characterization analysis methods

Wastewater characterization is the basis for process design and operation optimization of wastewater treatment plants (WWTPs). In this work, a comprehensive study of the respirometry method has been performed to evaluate the biodegradable organic matters of wastewater. First, the optimal initial substrate to biomass ratio (S0/X0) was confirmed. Second, under the optimal S0/X0, the degradation curves of wastewater carbon oxygen demand (COD) components rapidly biodegradable COD (RBCOD) and slowly biodegradable COD (SBCOD) were obtained. Third, the Mann–Kendall test was performed to confirm the time point (t2) when endogenous respiration levels were reached, and the hydrolysis model was used to determine the time point (t1) of the SBCOD degradation stage. Considering the results, an adequate wastewater COD characterization method for RBCOD and SBCOD has been proposed. This study provides strong support to carry out effective and feasible process design, process diagnosis and optimization capability, can help achieve refined and stable operational management of WWTPs.

The call for regional design code from the regional discrepancy of microbial communities in activated sludge.

Discerning the differences in activated sludge (AS) microbial community due to geographic location and environmental and operational factors is of great significance for precise design and maintenance of wastewater treatment plants (WWTPs). Hence, in this study, 150 AS samples collected from WWTPs in South China and North China were analyzed by 16S rRNA gene sequencing. In general, AS microbial community in North China had lower diversity, higher proportions of stochastic assembly (35.7% v.s. 15.8%) and more network keystone species (19 v.s. 5) compared with southern AS community. Conductivity and SRT had significant effects on AS community in both regions. Latitude, annual mean temperature, and influent BOD, COD, and ammonia influenced South China community significantly, while pH and influent total phosphorus affected North China community. To achieve stable performance, southern WWTPs should carefully monitor fluctuations in wastewater characteristics, while northern WWTPs should monitor AS communities for shifts in the dominant taxa from immigrant strains brought in through the influent. Additionally, WWTPs in North China should be aware of the need to proactively control sludge bulking because of the high abundance and occurrence of Haliscomenobacter in these AS communities. MAIN FINDING: The call for regional design based on the regional discrepancy of microbial communities in activated sludge is uncovered and according suggestions were given.

Design and Optimisation of Wastewater Treatment Plant for the Poultry Industry

The objective of this study is to optimise the wastewater treatment plant of poultry industry. The optimisation of simulation model was done using the SuperPRO designer as simulator. The performance of the wastewater treatment plant for the poultry industry has improved significantly at the minimum cost. The COD value reduced from 133 mg/L to 0.05 mg/L at the discharge stream 1 and 73.7 mg/L for discharge stream 2. In addition, the BOD5 value reduced from 66.7 mg/L to 0.03 mg/L at the discharge stream 1 and 47.1 mg/L at the discharge stream 2. Further to this, the TTS reduced from 33.3 mg/L to 0.0 mg/L at the discharge stream 1 and 1.69 mg/L at the discharge stream 2. Oil and grease also reduced from 3.3 mg/L to 0.024 mg/L at the discharge stream 1 and 18.7 mg/L at the discharge stream 2. The existing model and system can improve the wastewater treatment plant of poultry industry.

Penerapan Geometri dalam Perencanaan Instalasi Pengolahan Air Limbah Domestik : Studi Kasus Perumahan Mutiara Sartika, Kota Kendari

Penerapan konsep geometri sederhana untuk mendesain suatu instalasi pengolahan air limbah (IPAL) domestik penting dilakukan karena mengacu pada bangun ruang tiga dimensi untuk membuat bak penampungan. Oleh sebab itu dalam penelitian ini, kami menerapkan sistem geometri sederhana untuk perencanaan desain bak penampungan yang dapat diaplikasikan dibeberapa kawasan perumahan sederhana (Perumahan Mutiara Sartika-Kota Kendari). Hasil menunjukkan bahwa dengan kebutuhan konsumsi air bersih sebesar 150 L/hari/orang dengan jumlah perumahan 68 rumah type 36 dan 5 orang/rumah maka jumlah limbah yang dihasilkan sebesar 40.8 m3/hari. Sehingga dimensi bak penampungan air limbah yang dibangun berbentuk persegi panjang dengan total volume penampungan 79,1 m3 dengan perkiraan waktu tinggal selama 29 jam memperhatikan beberapa fungsi unit pengolahan. Berdasarkan hasil penelitian ini diharapkan dapat membantu untuk mengaplikasikan desain IPAL sederhana untuk pembangunan perumahan.

Effect of sewage sampling frequency on determination of design parameters for municipal wastewater treatment plants.

The uncertainty associated with the determination of load parameters, which is a key step in the design of wastewater treatment plants (WWTPs), was investigated on the basis of data sets from 58 WWTPs. A further analysed aspect was the organic load variations associated with variable sewage temperatures. Data from 26 WWTPs with a high inflow sampling frequency was used to simulate scenarios to investigate the effect of lower sampling frequencies through a Monte Carlo approach. The calculation of 85-percentile values for chemical oxygen demand (COD) loadings based on only 26 samples per year is associated with a variability of up to ±18%. Approximately 90 samples per year will be necessary to reduce this uncertainty for estimation of COD loadings below 10%. Hence, a low sampling frequency can potentially lead to under- or overestimation of design parameters. Through an analogous approach, it was possible to identify uncertainties of ±11% in COD loading when weekly average data was used with four samples per week. Finally, a tendency to lower COD input loads with increasing temperatures was identified, with a reduction of about 1% of the average loading per degree Celsius.

Risk Assessment Model for Planning and Design Processes of Wastewater Treatment Plants

Before joining the European Union, Serbia faces a big task related to the treatment and purification of wastewater. The capital of Serbia, Belgrade, and some larger cities do not have wastewater treatment plants. Although there are no plants in larger cities in Serbia, they still exist on the territory of the state itself. However, either they are not in good condition, or they do not work with the projected capacity or they do not work at all. This paper presents the model for risks quantification for the planning and design processes of wastewater treatment plants in which the risks are divided into 6 categories: legal, financial and economic, logistics, environmental protection, management and design risks. 37 risks have been defined, analyzed and evaluated by the experts participating in the Delphi method. Experts in various fields dealing with the planning, design or construction of wastewater treatment plants were selected to assess the risks through 2 rounds of Delphi methods and reach the consensus on major risks. By using statistical methods, it is determined that the experts reached the consensus after which each risk received its own relative weighting coefficient. Risk model has been initially verified by experts from Delphi team on two projects during construction phase. This model is important in the initial phases of the project, when the investor starts the project, as well as in the design phases.

A Data-Driven Soft Sensor to Forecast Energy Consumption in Wastewater Treatment Plants: A Case Study

Energy consumption is vital to the global costs of wastewater treatment plants (WWTPs). With the increase of installed WWTPs worldwide, the modeling and forecast of their energy consumption have become a critical factor in WWTP design to meet environmental and economic requirements. The accurate and swift energy consumption forecasting soft-sensors are not only supportive to the daily electric and financial budgeting by WWTP practitioners on the micro-scale, but also beneficial to local municipal operation and fundamental to regional environmental impact estimation on the macro-scale. Energy consumption in WWTPs is influenced by different biological and environmental factors, making it complicated and challenging to build soft-sensors. This article intends to provide short-term forecasting of WWTP energy consumption based on data-driven soft sensors using traditional time-series and deep learning methods. Ten data-driven soft sensors, including the ordinary least square, exponential smoothing state space, local regression, auto-regressive integrated moving average (ARIMA), structural time series model, Bayesian structural time series, non-linear auto-regressive, long short-term memory with and without updates, and gated recurrent units have been investigated and compared for WWTP energy consumption forecasting. Energy consumption time-series data from a membrane bioreactor-based WWTP in the middle east is used to evaluate the performances of the proposed soft-sensors. Results showed that ARIMA achieved slightly improved performances, among others. The employment of adaptive deep learning-based soft sensors is expected to enhance the capabilities of the deep models to quickly and accurately follow the trend of future data.

Seasonal Dynamics of the Activated Sludge Microbiome in Sequencing Batch Reactors, Assessed Using 16S rRNA Transcript Amplicon Sequencing.

Activated sludge is comprised of diverse microorganisms which remediate wastewater. Previous research has characterized activated sludge using 16S rRNA gene amplicon sequencing, which can help to address questions on the relative abundance of microorganisms. In this study, we used 16S rRNA transcript sequencing in order to characterize "active" populations (via protein synthesis potential) and gain a deeper understanding of microbial activity patterns within activated sludge. Seasonal abundances of individual populations in activated sludge change over time, yet a persistent group of core microorganisms remains throughout the year which are traditionally classified on presence or absence without monitoring of their activity or growth. The goal of this study was to further our understanding of how the activated sludge microbiome changes between seasons with respect to population abundance, activity, and growth. Triplicate sequencing batch reactors were sampled at 10-min intervals throughout reaction cycles during all four seasons. We quantified the gene and transcript copy numbers of 16S rRNA amplicons using real-time PCR and sequenced the products to reveal community abundance and activity changes. We identified 108 operational taxonomic units (OTUs) with stable abundance, activity, and growth throughout the year. Nonproliferating OTUs were commonly human health related, while OTUs that showed seasonal abundance changes have previously been identified as being associated with floc formation and bulking. We observed significant differences in 16S rRNA transcript copy numbers, particularly at lower temperatures in winter and spring. The study provides an analysis of the seasonal dynamics of microbial activity variations in activated sludge based on quantifying and sequencing 16S rRNA transcripts.IMPORTANCE Sequencing batch reactors are a common design for wastewater treatment plants, particularly in smaller municipalities, due to their low footprint and ease of operations. However, like for most treatment plants in temperate/continental climates, the microbial community involved in water treatment is highly seasonal and its biological processes can be sensitive to cold temperatures. The seasonality of these microbial communities has been explored primarily in conventional treatment plants and not in sequencing batch reactors. Furthermore, most studies often only address which organisms are present. However, the activated sludge microbial community is very diverse, and it is often hard to discern which organisms are active and which organisms are simply present. In this study, we applied additional sequencing techniques to also address the issues of which organisms are active and which organisms are growing. By addressing these issues, we gained new insights into seasonal microbial populations dynamics and activity patterns affecting wastewater treatment.

On‐site wastewater treatment using reactive filter media

AbstractThe aim of this study is to reduce the phosphate concentration in treated wastewater using a small amount of the reactive filter media, Filtralite P. Biologically treated wastewater was passed through a filter with 215 g of Filtralite P. In the laboratory, the phosphate removal efficiency was 51% at a flow speed of 0.87 m/h. Under real conditions, in an experimental stand filled with 0.5 m3 of Filtralite P, the phosphate removal efficiency was 85% and the removal efficiency of total suspended solids was 57% after a 5‐month period. The residual phosphate concentration in the filtrate from the experimental stand was 1 mg/L of PO4‐P after the 5‐month period. The experimental filtration plant was buried in the ground, and it did not freeze and worked well under winter conditions. The results of this study can be useful in the design and development of tertiary wastewater treatment plants in view of their sustainability potential.

Living on the edge: Prospects for enhanced biological phosphorus removal at low sludge retention time under different temperature scenarios

The design of new wastewater treatment plants with the aim of capturing organic matter for energy recovery is a current focus of research. Operating with low sludge residence time (SRT) appears to be a key factor in maximizing organic matter recovery. In these new configurations, it is assumed that phosphorus is chemically removed in a tertiary step, but the integration of enhanced biological phosphorus removal (EBPR) into these short-SRT systems seems to be an alternative worth studying. A key point of this integration is to prevent the washout of polyphosphate accumulating organisms (PAO) despite the low SRT applied. However, the minimum SRT required to avoid PAO washout depends on temperature, due to its effects on reaction kinetics, gas transfer rates, biomass growth and decay rates. This work includes a wide range of short and long-term experiments to understand these interactions and shows which combinations of SRT and temperature are detrimental to PAO growth. For example, an EBPR system operating at 20 °C and SRT = 5 d showed good performance, but EBPR activity was lost at 10 °C. EBPR operated at SRT = 10 d had 86% P removal at 20 °C but decreased to 71% at 15 °C and progressively lost its activity at lower temperature. The temperature coefficient obtained for PAO show a low degree of temperature dependence (θ = 1.047 ± 0.014), and should be considered when designing short-SRT systems with EBPR.

Sustainable wastewater treatment plants design through multiobjective optimization

Nowadays, an adequate design of wastewater treatment plants taking into consideration all sustainability dimensions– economic, environmental and social- is fundamental. This can be achieved by implementing systematic methodologies where conceptual and mathematical tools can be used together. This contribution proposes a framework that uses total cost, consumed energy, and reclaimed wastewater as sustainability metrics. A mixed-integer nonlinear programming problem arises from a general superstructure for wastewater treatment plants. A case study from Mexico City is solved by a hybrid multiobjective optimization approach that combines lexicographic and ε-constraint methods. Solutions are provided in the form of a Pareto front. A modified technique for order of preference by similarity to ideal solution (M-TOPSIS) analysis is used as a multiple criteria decision-making tool to find the best trade-off solution. The optimal sustainable configuration resulted consists of three levels of treatment and 100% of treated water reuse.

The SPPD-WRF Framework: A Novel and Holistic Methodology for Strategical Planning and Process Design of Water Resource Factories

This paper guides decision making in more sustainable urban water management practices that feed into a circular economy by presenting a novel framework for conceptually designing and strategically planning wastewater treatment processes from a resource recovery perspective. Municipal wastewater cannot any longer be perceived as waste stream because a great variety of technologies are available to recover water, energy, fertilizer, and other valuable products from it. Despite the vast technological recovery possibilities, only a few processes have yet been implemented that deserve the name water resource factory instead of wastewater treatment plant. This transition relies on process designs that are not only technically feasible but also overcome various non-technical bottlenecks. A multidimensional and multidisciplinary approach is needed to design water resource factories (WRFs) in the future that are technically feasible, cost effective, show low environmental impacts, and successfully market recovered resources. To achieve that, the wastewater treatment plant (WWTP) design space needs to be opened up for a variety of expertise that complements the traditional wastewater engineering domain. Implementable WRF processes can only be designed if the current design perspective, which is dominated by the fulfilment of legal effluent qualities and process costs, is extended to include resource recovery as an assessable design objective from an early stage on. Therefore, the framework combines insights and methodologies from different fields and disciplines beyond WWTP design like, e.g., circular economy, industrial process engineering, project management, value chain development, and environmental impact assessment. It supports the transfer of the end-of-waste concept into the wastewater sector as it structures possible resource recovery activities according to clear criteria. This makes recovered resources more likely to fulfil the conditions of the end-of-waste concept and allows the change in their definition from wastes to full-fledged products.

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.

Low complexity wastewater treatment process in developing countries: A LCA approach to evaluate environmental gains

Reliable Life Cycle Assessment (LCA) indicators for wastewater treatment plants (WWTP) construction and operation phases are still a demand mainly in developing countries. Thus, the purpose of this paper was to present and discuss the environmental performance of a full-scale WWTP installed in a Brazilian city using LCA approach. The treatment process consists of a UASB reactor followed by constructed wetlands, which makes it particularly attractive to developing countries due to its operational simplicity. The Life Cycle Inventory (LCI) was developed from a WWTP design and operation data including those of untreated wastewater and effluent quality. The results show that the environmental impacts from construction phase should not be neglected in LCA studies of low complexity treatment technologies (e.g. UASB reactor, constructed wetlands and pond systems). There is a trade-off between the use of materials and energy for construction and the low energy and materials consumption during the operation phase in these systems. The majority share of hydroelectric generation in the energy matrix and the combination of anaerobic and natural processes for wastewater treatment have contributed to a smaller impact potential for the operation phase. The LCA approach should be associated with plans and actions to face the challenges of providing wastewater treatment in developing countries. Only in this way, compliance with the eco-efficiency targets and protect public health will be guaranteed.

The effects of temperature, mixed liquor suspended solids and velocity on the removal of organic pollutants and kinetic modelling in wastewater sewer systems

ABSTRACT Wastewater materials change during transformation in sewer collection system. This study was conducted to evaluate the effects of temperature, mixed liquor suspended solids (MLSS) and velocity on the removal of organic pollutants and kinetic modelling in sewer systems. To evaluate the kinetics of organic pollutants, a pilot system was fabricated using a reactor in the laboratory scale. Chemical oxygen demand (COD) changes were assessed within 6 h of wastewater cycling in the reactor. The First order, Grau and Stover-Keane Canon models were used for predicting the removal of organic pollutants. The results showed that the pipeline removes COD during transformation. The results also showed that increased temperature, time and MLSS and decreased velocity significantly increased the removal of COD. Among the models used, the Grau and Stover-Keane Canon models efficiently predicted organic pollutants in real pipeline and the pilot system. It can be suggested that the Grau and Stover-Keane Canon models for predicting the removal of COD in sewer pipelines. The models can be used for more effective design and better real time control of wastewater treatment plants.