Wastewater Treatment Installations Research Articles

Analisis Parameter Fisika dan Kimia Outlet Ipal komunal Domestik Dusun Sukunan di Pusat Pengembangan Teknologi Tepat Guna Pengolahan Air Limbah (PUSTEKLIM) Yogyakarta

Instalasi Pengolahan Air Limbah (IPAL) komunal domestik Dusun Sukunan mengolah air limbah domestik yang dihasilkan dari kegiatan rumah tangga. Namun, pengolahan air limbah yang dilakukan belum menjamin kualitas air limbah yang dihasilkan. Dalam penelitian ini dilakukan pengujian beberapa parameter pada outlet IPAL komunal domestik Dusun Sukunan seperti TDS, TSS,BOD, dan pH. Pengujian kadar TDS dan TSS dilakukan dengan metode gravimetri, yaitu menimbang massa yang diperoleh setelah dilakukan pemisahan. Pengujian kadar BOD dilakukan dengan metode iodometri (modifikasi azida), yaitu menentukan volume larutan natrium tiosulfat (Na2S2O3) yang digunakan untuk titrasi iodium (I2) yang dibebaskan pada sampel hari ke-0 dan hari ke-5. Sedangkan penentuan nilai pH dilakukan dengan menggunakan pH universal. Berdasarkan pengujian diperoleh kadar TDS adalah 1440 mg/L, TSS adalah 80 mg/L, BOD adalah 70,5625 mg/L, dan memiliki pH 7. Hal tersebut menunjukkan bahwa terdapat parameter yang melebihi baku mutu air limbah domestik. Parameter tersebut adalah TSS, sedangkan parameter TDS, BOD, dan pH memenuhi persyaratan.

Activated Carbon and Coconut Coir with the Incorporation of ABR System as Greywater Filter: The Implications for Wastewater Treatment

Greywater refers to wastewater generated from domestic activities, which do not contain fecal contamination. Therefore, this study aims to treat greywater in Makassar city to speed up the water cycle and enable reuse, as an environmental conservation strategy. The water parameters measured were pH, Turbidity, Total Suspended Solid (TSS), Biological Oxygen Demand (BOD), and Chemical Oxygen Demand (COD). According to the results, the greywater’s BOD, COD, and TTS contents were 49.98 to 54.88 mg/L, 509 to 655 mg/L, and 404.40 to 464.65 mg/L, respectively, all of which exceed WHO wastewater quality standards. The use of a wastewater treatment installation comprising a combination of Activated Carbon (AC) and Coconut Coir (CC) with the incorporation of the Anaerobic Baffle Reactor (ABR) system as a greywater filter successfully reduced the city’s greywater pollution. In addition, the new BOD content fulfills the environmentally safe wastewater standards, while the new COD and TSS contents were 152 mg/L to 184 mg/L and 59.68 mg/L to 77.42 mg/L, respectively, which are close to the WHO domestic wastewater quality standards.

Advanced Electron Beam (EB) Wastewater Treatment System with Low Background X-ray Intensity Generation

Electron beam wastewater treatment is a very effective method for the destruction of organic and microbiological pollutants. The technology was implemented for municipal and textile industry wastewater treatment. Availability of electron accelerators characterized with different operation parameters make the technology applicable for different end-users and also for installation in confined spaces. In such a case, the design of wastewater irradiation room has to take into account the limited space available for shielding construction, which must restrict X-ray emission. Considering construction of an irradiation room for water treatment facility, it is important to focus not only on a stream formation for irradiation to achieve the desired electron penetration, but also on the reduction in x-ray generation. In the presented work, the X-ray field was tested, using modelling and experimental methods. The final results gave an advanced solution, which can be used in the installation of wastewater treatment, ballast and other types of origin, providing low cost shield and good radiation protection measures.

Genetic microbial faecal source tracking: rising technology to support future water quality testing and safety management

Recent developments in water resource monitoring have increased the demand for the reliable identification of faecal pollution sources, also defined as microbial (faecal) source tracking (MST). Standardized faecal indicator bacteria (SFIB) enumeration does not directly support MST, as SFIB occur in animal and human sources. The aim of this study was to rigorously evaluate the applicability of host-associated faecal genetic MST markers detected by quantitative PCR (qPCR) at representative Austrian water resources (ground-, surface-, raw and treated wastewater, n = 196 samples) with high importance for the water management sector. Groundwater covered a gradient of non- (i.e., deep wells) to surface influenced resources (i.e., karst and shallow wells). In addition, single faecal excreta from humans as well as representative livestock and wildlife species were collected to evaluate the faecal source-specificity and -sensitivity of the MST assays. Genetic MST marker resistance against UV irradiation was evaluated in on-site ground and wastewater treatment installations. Bacteroides-based human- (HF183II, BacHum), ruminant- (BacR), and pig-associated (Pig2Bac) MST marker qPCR quantification was performed in concert with cultivation of E. coli, intestinal enterococci, and Clostridium perfringens (SFIB diagnostics). The selected MST makers revealed high faecal source identification capacity for the Austrian water compartments and quantitatively reflected the selected faecal pollution gradient. The study also demonstrated that SFIB data can efficiently be combined with MST data to solve previously unanswered questions in water safety monitoring and management (e.g., support pollution source-targeted catchment protection, hazard assessment, and health risk management). Further research and development needs are discussed to exploit the full power of MST technology. In conclusion, this study illustrates the capacity of molecular faecal pollution diagnostics to revolutionize water quality testing in the decades to come.

Lifecycle Design of Disruptive SCADA Systems for Waste-Water Treatment Installations

Capacity to remotely monitor and control systems for waste-water treatment and to provide real time and trustworthy data of system’s behavior to various stakeholders is of high relevance. SCADA systems are used to undertake this job. SCADA solutions are usually conceptualized and designed with a major focus on technological integrability and functionality. Very little contributions are brought to optimize these systems with respect to a mix of target functions, especially considering a lifecycle perspective. In this paper, we propose a structured methodology for optimizing SCADA systems from a lifecycle perspective for the specific case of waste-water treatment units. The methodology embeds techniques for handling entropy in the design process and to assist engineers in designing effective solutions in a space with multiple constrains and conflicts. Evolutionary multiple optimization algorithms are used to handle this challenge. After the foundation of the theoretical model calibrated for the specific case of waste-water treatment units, a practical example illustrates its applicability. It is shown how the model can lead to a disruptive solution, which integrates cloud computing, IoT, and data analytics in the SCADA system, with some competitive advantages in terms of flexibility, cost effectiveness, and increased value added for both integrators and beneficiaries.

Evaluation of Illicit Drug Consumption by Wastewater Analysis Using Polar Organic Chemical Integrative Sampler as a Monitoring Tool.

Illicit drug abuse is a worldwide social and health problem, and monitoring illicit drug use is of paramount importance in the context of public policies. It is already known that relevant epidemiologic information can be obtained from the analysis of urban residual waters. This approach, named wastewater-based epidemiology (WBE), is based on the measurement of specific markers, resulting from human biotransformation of the target drugs, as indicators of the consumption of the compounds by the population served by the wastewater treatment installation under investigation. Drug consumption estimation based on WBE requires sewage sampling strategies that express the concentrations along the whole time period of time. To this end, the most common approach is the use of automatic composite samplers. However, this active sampling procedure is costly, especially for long-term studies and in limited-resources settings. An alternative, cost-effective, sampling strategy is the use of passive samplers, like the polar organic chemical integrative sampler (POCIS). POCIS sampling has already been applied to the estimation of exposure to pharmaceuticals, pesticides, and some drugs of abuse, and some studies evaluated the comparative performances of POCIS and automatic composite samplers. In this context, this manuscript aims to review the most important biomarkers of drugs of abuse consumption in wastewater, the fundamentals of POCIS sampling in WBE, the previous application of POCIS for WBE of drugs of abuse, and to discuss the advantages and disadvantages of POCIS sampling, in comparison with other strategies used in WBE. POCIS sampling is an effective strategy to obtain a representative overview of biomarker concentrations in sewage over time, with a small number of analyzed samples, increased detection limits, with lower costs than active sampling. Just a few studies applied POCIS sampling for WBE of drugs of abuse, but the available data support the use of POCIS as a valuable tool for the long-term monitoring of the consumption of certain drugs within a defined population, particularly in limited-resources settings.

EVALUASI KINERJA INSTALASI PENGOLAHAN AIR LIMBAH RSD MANGUSADA KABUPATEN BADUNG

The Mangusada Regional General Hospital (RSD) as a provider of health facilities certainly produces liquid waste in every operational activity. Wastewater in the Wastewater Treatment Installation (WWTI) RSD Mangusada contains Biological Oxygen Demand (BOD5), Chemical Oxygen Demand (COD), Total Suspended Solid (TSS), ammonia, total coliform, Total Dissolved Solid (TDS), detergent, oil and fat. This study aims to evaluate the performance of the WWTI as well as to determine the content in the wastewater after being treated by the IPAL RSD Mangusada according to the reference quality standards of the Governor of Bali Regulation No.16/2016 and Regulation of the Minister of Environment and Forestry of the Republic of Indonesia Number: P.68/Menlhk/Setjen/Kum.1/8/2016. The wastewater treatment system at RSD Mangusada uses a biological system. The data used in the analysis are secondary data, namely the Bed Occupation Rate (BOR) data in June 2020, the total number of beds, the average discharge of outlets in June 2020 and parameters of the quality and quantity of wastewater in the inlet and outlet of WWTI from January 2020 to July 2020. Based on the results of testing the quality and quantity of wastewater at the WWTI of RSD Mangusada outlet, the content of waste water in the outlet of WWTI is in accordance with the regulatory standards for the reference quality standards. In addition, the effectiveness of the efficiency of the WWTI at RSD Mangusada succeeded in reducing the ammonia content of 92.35%, BOD5 64.03%, COD 63.97%, TSS 67.03%, oil and fat 64.64%, total coliform 76.84%. , and detergent at 76.25%. But the efficiency of the WWTI of RSD Mangusada was not good enough in reducing the TDS content of -3.92%.

ANALISA DISPERSI PM2,5 MENGGUNAKAN MODEL GAUSS POINT SOURCE DIKAWASAN INDUSTRI DAN DESAIN VENTURI SCRUBBER BESERTA IPAL UNTUK EFFLUENT VENTURI (Studi Kasus : Industri Peleburan Aluminium PT.X Kecamatan Kesamben, Jombang)

Kegiatan Industri Peleburan Aluminium PT.X mengakibatkan kualitas udara di sekitar industri menurun hal tersebut ditandai oleh beberapa keluhan dari masyarakat, PM2,5 merupakan salah satu partikulat yang ditimbulkan dari proses peleburan aluminium yang mana sangat berpengaruh negatif terhadap kesehatan manusia. Tujuan dari penelitian adalah menganalisis konsentrasi PM2,5 di kawasan penduduk menggunakan model gauss point source serta mendesain alat pengendali pencemar udara venturi scrubber untuk dapur peleburan aluminium beserta instalasi pengolahan air limbah. Hasil perhitungan menunjukkan bahwa konsentrasi PM2,5 di kawasan industri PT.X titik 1 (50 m dari lokasi industri) yaitu 2,7 x 10-5/m3, titik 2 (100 m dari lokasi industri) yaitu 6,7 x 10-6/m3, titik 3 (200 m dari lokasi industri) yaitu 1,6 x 10-6/m3 dari ketiga titik tersebut masih memenuhi baku mutu udara ambient Peraturan Pemerintah Republik Indonesia No. 41 Tahun 1999. Hasil perhitungan desain venturi scrubber diperoleh dimensi venturi diameter throat (lebar) 0,55 m, panjang throat 1,65 m, dan panjang bagian diverging 2,2 m prosentase removal partikulat PM2,5 sebesar 95% dan hasil perhitungan desain IPAL diperoleh untuk bangunan koagulasi dengan dimensi Panjang 0,86 m, lebar 0,86 m dan tinggi 1,2 m, bangunan Flokulasi diperoleh panjang 2,1 m , lebar 4,2 m dan tinggi 2 m, bangunan Sedimentasi dengan diameter 5,6 m dan tinggi 1,57 m. Rencana Anggara Biaya dari perhitungan desain didapatkan untuk desain Venturi Scrubber dan IPAL yaitu sebesar Rp. 83.647.421.

A high-throughput assay to quantify protein hydrolysis in aerobic and anaerobic wastewater treatment processes.

Proteins, an important fraction of the organic matter in wastewater, typically enter a treatment facility as high molecular weight components. These components are degraded by extracellular protein hydrolytic enzymes, denoted as proteases. Adequate protein hydrolysis monitoring is crucial, since protein hydrolysis is often a rate-limiting step in wastewater treatment. However, current monitoring tools lack a high sample throughput and reliable quantification. Here, we present an improved assay for high-throughput protein hydrolysis rate measurements in wastewater treatment applications. A BODIPY FL casein model substrate was implemented in a microplate format for continuous fluorescent quantification. Case studies on a conventional and a high-rate aerobic municipal wastewater treatment plant and a lab-scale, two-stage, anaerobic reactor provided proof-of-concept. The assay presented in this study can help to obtain monitoring-based process insights, which will in turn allow improving biological performance of wastewater treatment installations in the future. KEY POINTS: • Protein hydrolysis is a crucial step in biological wastewater treatment. • Quantification of the protein hydrolysis rate enables in-depth process knowledge. • BODIPY FL casein is a suitable model substrate for a protein hydrolysis assay. • High sample throughput was obtained with fluorescent hydrolysis quantification. Graphical abstract.

Morpho-physiological analysis of aquatic plants for phytoremediation of wastewater from gold mine wastewater treatment installation (IPAL)

Several types of aquatic plants have a potential role in reducing pollutants from contaminated water through phytoremediation processes. The purpose of this study was to analyze the capacity of aquatic plants in phytoremediation process of cyanide and heavy metals from gold mine liquid waste, based on the growth and heavy metal deposition in the root and shoot. The study was conducted using a completely randomized design with two factors, i.e., the concentration of gold-mine wastewater (0%, 50%, and 100%) and the combination of two aquatic plants from 4 species (Eichhornia crassipes, Neomarica longifolia, Hydrilla verticillata, and Pistia stratiotes). The results showed that gold mine wastewater generally reduced the growth rate of all the plants, especially at 100% wastewater concentration. The treatment with gold mine wastewater caused an increase in lipid peroxidation specified by the increase of root and leaf MDA content, while it decreases leaf chlorophyll content significantly. The best combination of aquatic plants for gold mine phytoremediation was shown by N. longifolia – P. Stratiotes based on the smallest dry weight reduction and the greatest reduction of cyanide, Pb and Hg from the media.

PENINGKATAN PRODUKTIVITAS MELALUI UPAYA ENVIROMENTAL RISK ANALYSIS UNTUK MENDUKUNG PELAKSANAAN GREEN PRODUCTIVITY

PG XYZ as one of the sugar industries that have the potential for waste pollution needs to make improvements both in the production process and in the management of its environment. With various existing waste conditions such as in industrial wastewater. Therefore, a systematic application is needed to minimize the possibility of environmental risks. so that identification, assessment and analysis of environmental risk based on the concept of environmental risk management using qualitative methods, semi-quantitative methods and the significance of aspects. followed by EPI calculation to support the implementation of green productivity. the objectives of this study are to identify and analyze environmental risks in the sugar processing industry wastewater based on the concept of environmental risk management. Evaluate the factors that influence the productivity of environmental performance to support the implementation of green productivity. The result of this study is that installation of wastewater treatment has a low risk with a total risk value of 77 which means that management is carried out by routine procedures. Whereas the results of the environmental risk assessment of production activities which have the most environmental impact are turbine oil lubrication at the boiler station with a score of 1701, at the blotong process purification station with a score of 729. Factors that influence environmental performance productivity are the performance of the boiler station and oil from the turbine steam that is carried into liquid waste. EPI index measurement results have a positive value of 35.24%, this indicates that the environmental performance of the sugar mills studied is good enough.

Hotspot identification in the Indonesian tempeh supply chain using life cycle assessment

Tempeh is a traditional Indonesian fermented soybean product, which plays an essential role in its culture and economy and forms an important non-meat protein source in the diet of its people. Nationally, there are around 80,000 small and medium tempeh producers consuming more than 1 million tonnes of soybeans annually. This raw material is however mostly imported from the USA, which might bring unintended environmental consequences. This paper evaluates the life cycle environmental performance of tempeh by comparing existing tempeh production alternatives in Indonesia, identifying impact hotspots and analysing parameter sensitivity for possible improvement. A life cycle assessment (LCA) was conducted including 11 CML baseline impact categories for a case study of tempeh production in West Java. The study differentiated between two levels of technology, being conventional and hygienic tempeh production. The latter was characterised by the elimination of firewood, an increased energy and material intensity and higher product acceptance in certain market segments. Assuming that it best represents future practices, sensitivity analysis were further carried out on the hygienic tempeh production system. Minor differences in environmental impact exist between the conventional and hygienic production systems. For example, the global warming impact of 1 kg of either conventional or hygienic tempeh is between 0.9 and 1.0 kg CO2-eq. Where the soybean cultivation stage is the main contributor to the indicator results for land use and eutrophication, the transport stage is the main contributor to human toxicity, eco-toxicity, stratospheric ozone depletion, climate change, photochemical oxidation and acidification. Road transport within Indonesia was found to dominantly contribute to the total transport impact and to be a highly sensitive parameter, showing great variability due to changes in distance and assumed average load. This study also found that assumed average load from ecoinvent transport services may not reflect average transport conditions in Indonesia. Hotspots of Indonesian tempeh are related to the transport of soybeans to the tempeh factory and their cultivation. This means that the processing of soybeans into tempeh at the factory only has a small contribution to total environmental impacts. Therefore, improvements aimed at environmental gains should focus mainly on the development of locally grown soybean or other beans and efficient modes of local transport, and to a lesser extent on the installation of wastewater treatment, increased use of renewable energy and increasing energy efficiency.

Kajian Pengelolaan Instalasi Pengolahan Air Limbah di Rumah Sakit

Risk management is a process of knowing, analyzing, and controlling risks of every activity in product and, service sectors. The aims are the process runs effectively and efficiently. One of the ISO studies on risk management has been guided in ISO 31000. This ISO provides a standard framework with the title "Risk Management-Principles and Guidelines on Implementation". Based on the sources in the Ministry of Health in 2016, there are 2,488 hospitals spread throughout Indonesia. However, only 10.29% of hospitals have ability to control the Wastewater Treatment Plant (WWTP) properly. The purposes of this research are determining risk priority of Wastewater Treatment Installation and prioritizing risk evaluation of WWTP at Ibnu Sina hospital, Padang. In this research, fuzzy AHP method was used. The questionnaire was validated by environmental department which monitors hospitals’ waste. After ranking the priority risk, Risk Breakdown Structure method was then being used to evaluate the risk that has potentiallty in waste water processing.The result from the fuzzy AHP are five risks, the main priority risk is the pipe with sub risk of liquid waste stuck with value of 0,0779. The second risk is septictank with excess nitrification sub risk with value of 0,0713. The third risk is the sampit with subcritical liquid waste spilled with value of 0,0642. The fourth risk is the lack quality of human resources with the weight value of 0,0590 and the fifth risk is the blower with the condition is not feasible to use with the weight value of 0,0548.

BIAYA EKSTERNAL DAN INTERNALISASI LIMBAH PABRIK KELAPA SAWIT

The product of waste water from the process of millers may cause externality. In order to prevent the externality, millers has to internalize it by developing an installation of waste water treatment. The current is not sufficient for treating whole waste from the CPO process, therefore, can generate externality and external costs to community. This study aims to estimate the external cost and propose three alternatives of alternative of internalizations. The result of the research shows that the external cost is 146,194,433 IDR/year. The alternative of internalization offered are; compensation cost payment, sludge pond recovery, and well development.

Revitalization model of tapioca industry through environmental awareness reinforcement for minimizing water body contamination

Tapioca industry in Margoyoso District is a household industry which positively contributes to the growth of the region's economy as it is able to absorb 6,61% of productive age populationor absorb 3,300 workers.On the other hand, the industry impacts contamination of river water in the form of pollutants dissolved materials and particulates into water bodies so that the quality of water decreases even does not work anymore in accordance with the allocation for irrigation or run off of agriculture. The purpose of this research is to: strengthen environmental awareness; calculate the success of the reinforcement action and minimize water body contamination. The research was conducted in two villages of tapioca industry center in Margoyoso district - Pati Regency Administration Area. The determination coefficient of R Square is 0.802 which indicates a successful effort of 80.2%. Regression equation Y = 34.097 + 0.608 X. Industrial entrepreneur's concern increased on 8.45 from total indicator or position to 70.72 so that the gradual effort showed success to minimize water contamination of Suwatu River. The business community of tapioca should build installation of wastewater treatment.

DISAIN PERENCANAAN INSTALASI PENGOLAHAN AIR LIMBAH (IPAL) DAN RE-USE AIR DI LINGKUNGAN PERHOTELAN

Denpasar is one of the number one tourist destination in the world. This city needs a lot of water resources with high quality to meet the needs of the hotel. While the Bali island with a relatively small area can not save the water resources in large numbers, the good management of water resources and efficiency use of water is realy needed. Hotel is one of the largest water users in the city of Denpasar. The water source is from deep ground water and PDAM with the same quality. If someday deficit water and sea water intrusion in Denpasar happened, the hotel will be accused as one major cause of this problem. To overcome these problems, environmentally friendly hotel management will be needed to achieve "GREEN HOTEL RESORT" programs in Bali, such as water usage efficiency, water recycle and protect environment from wastewater polution. To achieve this without reducing the amount of water consumption, can be done by using the technology of wastewater reuse, with technology Waste Water Treatment Installation (WWTP) and continued with the water quality improvement technology using multi media filters, ultra-filtration or reverse osmosis. Key words : Hotel yang ramah lingkungan, re-use air limbah

PENGELOLAAN AIR LIMBAH DOMESTIK DI DKI JAKARTA

Water pollution problem caused by household waste water in the region of DKI Jakarta, and more made worse by affecting of expanding settlement area in buffer zone around Jakarta which without provided with waste water facilities, so that all waste water thrown to public channel and finally flowing into river bodies in region of DKI Jakarta.To overcome the mentioned above Government of Province DKI Jakarta have released Regulation of Governor Province Special District Capital of Jakarta Number 122 Year 2005 About Management Of Domestic Water Waste In Province Special District Capital Of Jakarta. According To Regulation Of Governor of DKI Jakarta Number 122 Year 2005 Section 7 express that house building and non house building is obliged to manage domestic waste water before discharge to public channel or drainage. Planning of domestic waste water treatment installation which represent environmental utilities or building represent conditions in course of publication of Permit Directing Of Usage Of Land;Ground (SIPPT), Plan Arrange Situation Building ( RTLB), Permission Found Building (IMB), and awaking up of domestic waste water treatment installation represent conditions in course of publication of Permit of Building Usage (IPB) and Elegibility Use Building (KMB), and also licensing of operational of institution in charge related to such operational. Kata Kunci : Air limbah domestik, air limbah rumah tangga, pengelolaan.

Preliminary Study of Contamination Wastewater on Environment in Slaughterhouse of Merauke City

The purpose of this research is to know the contamination of waste water that happened in slaughterhouse (RPH) city of merauke. Data were obtained based on surveys and field observations and the sample used was RPH water waste each in repeat as many as 6 replications. Data analysis was done descriptively by comparing the result obtained with the standard of quality which have been determined. The results showed that the contamination of waste water all exceeded the quality standard except at pH value. The ALT content of wastewater in RPH 2790 x 104 and contains E. Coli and Salmonella microbes. The high content of BOD, COD, TTS, Ammonia and microbial contamination is thought to be due to the absence of wastewater treatment installation (IPAL) at RPH in accordance with the standard. Proper handling of ammonia waste can reduce the amount of carbon in the atmosphere.

Assessment of the technological reliability of a hybrid constructed wetland for wastewater treatment in a mountain eco-tourist farm in Poland.

The aim of the present study was to assess the technological reliability of a domestic hybrid wastewater treatment installation consisting of a classic three-chambered (volume 6 m3) septic tank, a vertical flow trickling bed filled with granules of a calcinated clay material (KERAMZYT), a special wetland bed constructed on a slope, and a permeable pond used as a receiver. The test treatment plant was located at a mountain eco-tourist farm on the periphery of the spa municipality of Krynica-Zdrój, Poland. The plant's operational reliability in reducing the concentration of organic matter, measured as biochemical oxygen demand (BOD5) and chemical oxygen demand (COD), was 100% when modelled by both the Weibull and the lognormal distributions. The respective reliability values for total nitrogen removal were 76.8% and 77.0%, total suspended solids - 99.5% and 92.6%, and PO4-P - 98.2% and 95.2%, with the differences being negligible. The installation was characterized by a very high level of technological reliability when compared with other solutions of this type. The Weibull method employed for statistical evaluation of technological reliability can also be used for comparison purposes. From the ecological perspective, the facility presented in the study has proven to be an effective tool for protecting local aquifer areas.

Hydraulic characterization of an activated sludge reactor with recycling system by tracer experiment and analytical models

Fluid dynamic behaviour plays an important role in wastewater treatment. An efficient treatment requires the inexistence of certain hydraulic problems such as dead zones or short-circuiting flows. Residence time distribution (RTD) analysis is an excellent technique for detecting these inefficiencies. However, many wastewater treatment installations include water or sludge recycling systems, which prevent us from carrying out a conventional tracer pulse experiment to obtain the RTD curve of the installation. This paper develops an RTD analysis of an activated sludge reactor with recycling system. A tracer experiment in the reactor is carried out. Three analytical models, derived from the conventional pulse model, are proposed to obtain the RTD curve of the reactor. An analysis of the results is made, studying which model is the most suitable for each situation. This paper is useful to analyse the hydraulic efficiency of reactors with recycling systems.