scholarly journals Screening for Methane Utilizing Mixed Communities with High Polyhydroxybutyrate (PHB) Production Capacity Using Different Design Approaches

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1579
Author(s):  
Rana Salem ◽  
Moomen Soliman ◽  
Ahmed Fergala ◽  
Gerald F. Audette ◽  
Ahmed ElDyasti
Keyword(s):  
Wastewater Treatment Plants ◽  
Production Capacity ◽  
Nitrogen Sources ◽  
Carbon Substrate ◽  
Type Ii ◽  
Operational Parameters ◽  
Phb Production ◽  
Accumulation Phase ◽  
Broad Interest ◽  
Microbial Samples

With the adverse environmental ramifications of the use of petroleum-based plastic outweighing the challenges facing the industrialization of bioplastics, polyhydroxyalkanoate (PHA) biopolymer has gained broad interest in recent years. Thus, an efficient approach for maximizing polyhydroxybutyrate (PHB) polymer production in methanotrophic bacteria has been developed using the methane gas produced in the anaerobic digestion process in wastewater treatment plants (WWTPS) as a carbon substrate and an electron donor. A comparison study was conducted between two experimental setups using two different recycling strategies, namely new and conventional setups. The former setup aims to recycle PHB producers into the system after the PHB accumulation phase, while the latter recycles the biomass back into the system after the exponential phase of growth or the growth phase. The goal of this study was to compare both setups in terms of PHB production and other operational parameters such as growth rate, methane uptake rate, and biomass yield using two different nitrogen sources, namely nitrate and ammonia. The newly proposed setup is aimed at stimulating PHB accumulating type II methanotroph growth whilst enabling other PHB accumulators to grow simultaneously. The success of the proposed method was confirmed as it achieved highest recorded PHB accumulation percentages for a mixed culture community in both ammonia- and nitrate-enriched media of 59.4% and 54.3%, respectively, compared to 37.8% and 9.1% for the conventional setup. Finally, the sequencing of microbial samples showed a significant increase in the abundance of type II methanotrophs along with other PHB producers, confirming the success of the newly proposed technique in screening for PHB producers and achieving higher PHB accumulation.

Performance evaluation of different wastewater treatment technologies operating in a developing country

2011 ◽  
Vol 1 (1) ◽  
pp. 37-56 ◽  
Author(s):  
Sílvia C. Oliveira ◽  
Marcos von Sperling
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Septic Tank ◽  
Operational Parameters ◽  
Technical Literature ◽  
Effluent Quality ◽  
Loading Rates ◽  
Treatment Processes ◽  
Treatment Technologies ◽  
Uasb Reactors

This article analyses the performance of 166 wastewater treatment plants operating in Brazil, comprising six different treatment processes: septic tank + anaerobic filter, facultative pond, anaerobic pond + facultative pond, activated sludge, UASB reactors alone, UASB reactors followed by post-treatment. The study evaluates and compares the observed effluent quality and the removal efficiencies in terms of BOD, COD, TSS, TN, TP and FC with typical values reported in the technical literature. In view of the large performance variability observed, the existence of a relationship between design/operational parameters and treatment performance was investigated. From the results obtained, no consistent relationship between loading rates and effluent quality was found. The influence of loading rates differed from plant to plant, and the effluent quality was dictated by several combined factors related to design and operation.

scholarly journals Efficient tetracycline removal from aqueous solutions using ionic liquid modified magnetic activated carbon (IL@mAC)

2021 ◽  
Author(s):  
Edris Bazrafshan ◽  
Amin Allah Zarei ◽  
Leili Mohammadi ◽  
Muhammad Nadeem Zafar ◽  
Maryam Foroughi ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Activated Carbon ◽  
Wastewater Treatment Plants ◽  
Correlation Coefficients ◽  
Antibacterial Drug ◽  
Adsorption Efficiency ◽  
Operational Parameters ◽  
Magnetic Activated Carbon ◽  
Urban Wastewater Treatment ◽  
Poor Absorption

Abstract Tetracycline (TCy) belongs to PPCPs is such an widely used antibacterial drug, which is discharged from urban wastewater treatment plants or agricultural effluents. Due to low metabolism, poor absorption, overuse, and misuse, TCy is considered as threat to environmental and its removal from waste-water is vital. In this research, a novel ionic liquid modified magnetic activated carbon nanocomposite (IL@mAC) was synthesized, characterized, and the adsorption efficiency of IL@mAC for removal of TCy was investigated under different operational parameters of pH (3–11); dose of IL@mAC (0.01–0.1 g/50 mL); reaction time (30–240 min), and initial TCy concentration (50-1500 mg/L). The IL@mAC characterization was done using XRD, VSM, SEM-EDX, BET, and FTIR. Results of equilibrium experiment showed that the highest removal efficiency (~ 98%) was obtained using 0.06 g of IL@mAC in 135 min at pH 7 and temperature 303 K. Considering the correlation coefficients (R2) for different adsorption models, it can be deduced that adsorption of TCy onto IL@mAC is better followed by Langmuir (0.9977) in comparison to Freundlich (0.9412), and Temkin (0.9536) models. Furthermore, Langmuir adsorption capacity was observed to be 666.7 mg/g. The regeneration study showed that IL@mAC retained around 85% TCy adsorption efficiency after 6th cycle. Finally, the present study indicates that the IL@mAC is of a high applicability and has extremely high adsorbent capacity to remove TCy from water compared to most of other benchmark adsorbents reported in literature.

scholarly journals Full-scale performance of selected starch-based biodegradable polymers in sludge dewatering and recommendation for applications

2017 ◽  
Vol 77 (1) ◽  
pp. 7-16 ◽  
Author(s):  
Kuangxin Zhou ◽  
Johan Stüber ◽  
Rabea-Luisa Schubert ◽  
Christian Kabbe ◽  
Matthias Barjenbruch
Keyword(s):  
Biodegradable Polymers ◽  
Wastewater Treatment Plants ◽  
Pilot Scale ◽  
Full Scale ◽  
Municipal Sewage ◽  
Municipal Sewage Sludge ◽  
Operational Parameters ◽  
Sludge Dewatering ◽  
Dewatered Sludge ◽  
Green Polymers

Abstract Agricultural reuse of dewatered sludge is a valid route for sludge valorization for small and mid-size wastewater treatment plants (WWTPs) due to the direct utilization of nutrients. A more stringent of German fertilizer ordinance requires the degradation of 20% of the synthetic additives like polymeric substance within two years, which came into force on 1 January 2017. This study assessed the use of starch-based polymers for full-scale dewatering of municipal sewage sludge. The laboratory-scale and pilot-scale trials paved the way for full-scale trials at three WWTPs in Germany. The general feasibility of applying starch-based ‘green’ polymers in full-scale centrifugation was demonstrated. Depending on the sludge type and the process used, the substitution potential was up to 70%. Substitution of 20–30% of the polyacrylamide (PAM)-based polymer was shown to achieve similar total solids (TS) of the dewatered sludge. Optimization of operational parameters as well as machinery set up in WWTPs is recommended in order to improve the shear stability force of sludge flocs and to achieve higher substitution potential. This study suggests that starch-based biodegradable polymers have great potential as alternatives to synthetic polymers in sludge dewatering.

scholarly journals KARAKTERISTIK DAN POTENSI PENGGUNAAN IRIDIATOR MERAH PUTIH UNTUK PENANGANAN PRODUK PANGAN HASIL PERTANIAN

2020 ◽  
Vol 15 (3) ◽  
pp. 155
Author(s):  
Ari Satmoko ◽  
Hyundianto Arif Gunawan ◽  
Bonang Sigit Trenggono ◽  
NFN Mujiono
Keyword(s):  
Production Capacity ◽  
Absorbed Dose ◽  
Food Product ◽  
Total Activity ◽  
Operational Parameters ◽  
Absorbed Dose Rate ◽  
Dried Fruits ◽  
Dose Uniformity ◽  
Absorbed Doses ◽  
Potential Use

<p>Iradiator gamma, yang diberi nama iriradiator Merah Putih, telah selesai dibangun dan diisi dengan sumber Cobalt-60 dengan kapasitas sekitar 300 kCi. Dirancang untuk multiguna, iriadiator ini harus dapat menyediakan berbagai dosis serap dari rendah hingga tinggi. Sistem kontrol mengijinkan 4 opsi kombinasi rak-rak sumber dengan opsi aktivitas terkceil adalah 41,2 kCi. Di dalam bungker, produk akan menjalani mekanisme laluan iradiasi dengan tujuan agar mendapatkan dosis serap iradiasi yang beragam. Bungker menyediakan 72 posisi iradiasi. Di setiap posisi iradiasi, gerakan produk dapat dihentikan untuk jeda waktu tertentu menyesuaikan dosis serap iradiasi yang diinginkan. Waktu minimum bagi produk menyelesaikan menkanisme laluan iradiasi adalah 78,5 menit. Pengujian dosis dosimetri menunjukkan bahwa laju dosis serap opsi pengoperasiaan aktivitas sumber terkecil adalah 0,22 kGy per jam. Rasio Dmaks/Dmin bergantung pada densitas produk. Untuk densitas 0,2, 0,4, dan 0,6 g/cm3, rasio keseragaman dosis masing-masing adalah 1,54, 1,65, dan 1,71. Kombinasi karakterisasi mekanik dan dosimetri mengantarkan pada dosis serap minimum yang mungkin diperoleh sebesar 0,29 kGy. Dengan batasan minimum ini, segala tujuan iradiasi yang membutuhkan lebih besar dari dosis tersebut sangat dimungkinkan menggunakan iradiator Merah Putih seperti untuk karantina buah segar, pengawetan biji-biji serelia, buah-buahan kering, dan lain-lain. Permasalahan kapasitas produk juga menjadi bahan pertimbangan. Kapasitas produksi iradiasi bergantung berbagai parameter seperti dosis serap iradiasi yang diinginkan dan densitas produk, serta parameter operasional lainnya. Jika dibutuhkan dosis serap iradiasi Gy dan densitas produk 0,4 gr/cm3, maka kapasitas produksinya adalah 3,17 ton/jam atau 76 ton/hari. Kapasitas dapat berubah bila parameter iradiator juga berubah.</p><p> </p><p><strong>Characterisation and Potential use of Irradiator Red and White for Handling Food Product Agricultural.</strong></p><p>A gamma irrdiator called Irradiator Merah Putih, has been contructed and loaded with Cobalt-60 sources having a total activity of about 300 kCi. Designed for multipurposes, the irriditor should be able to provide low-to-high absorbed doses. The control system allows 4 options for combination of source racks with the smallest activity option is 41.2 kCi. Inside the irridiator bunker, the product to be irradiated will undergo an irridiation source pass mechanism in order to obetain uniform irradition absorbed dose. The bunker provides as many as 72 irradiation positions. At its position, the product maybe stopped for certain period of delight adjusting the desired irradition dose. The minimum time for the product to complete the source pass mechanism is 78.5 minutes. The dosimetry test showed that the absorbed dose rate for the smallest source activy operation was 0.22 kGy/hr. The Dmax/Dmin ratio depend on the product densitiy. For densities 0.2, 0.4, and 0.6 g/cm3, the dose uniformity ratios were respectively 1.54, 1.65, and 1.71. The combination of both mechanical and dosimetry characterization leads to a minimum absorbed dose of 0.29 kGy. With this minimum restriction, any irradiation objective requiring greater than that dose is posible using the irradiator Merah Putih such as for fresh fruit, quarantine, presservation of ceral grains, dried fruits,and others. The irradiator’s throughput is also considered. The irradiation capasity depends on various parameters such as the desired irradiation absorbed dose and the density of thr product as well as other operational paramters. If a 400 Gy of irradiation of absorbed dose is required for a product with the density of 0.4 g/cm3, its production capacity is about 3.17 ton/h or 76 ton/day. The capasity may change when irradiator operational parameters are also change.</p>

scholarly journals An Overview of Recent Advancements in Microbial Polyhydroxyalkanoates (PHA) Production from Dark Fermentation Acidogenic Effluents: A Path to an Integrated Bio-Refinery

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4297
Author(s):  
Rijuta Ganesh Saratale ◽  
Si-Kyung Cho ◽  
Ganesh Dattatraya Saratale ◽  
Manu Kumar ◽  
Ram Naresh Bharagava ◽  
...  
Keyword(s):  
Volatile Fatty Acids ◽  
Renewable Energy Sources ◽  
Value Added ◽  
Cost Effective ◽  
Research Progress ◽  
Carbon Substrate ◽  
Operational Parameters ◽  
Biomass Resources ◽  
Fermentative Hydrogen ◽  
Hydrogen Synthesis

Global energy consumption has been increasing in tandem with economic growth motivating researchers to focus on renewable energy sources. Dark fermentative hydrogen synthesis utilizing various biomass resources is a promising, less costly, and less energy-intensive bioprocess relative to other biohydrogen production routes. The generated acidogenic dark fermentative effluent [e.g., volatile fatty acids (VFAs)] has potential as a reliable and sustainable carbon substrate for polyhydroxyalkanoate (PHA) synthesis. PHA, an important alternative to petrochemical based polymers has attracted interest recently, owing to its biodegradability and biocompatibility. This review illustrates methods for the conversion of acidogenic effluents (VFAs), such as acetate, butyrate, propionate, lactate, valerate, and mixtures of VFAs, into the value-added compound PHA. In addition, the review provides a comprehensive update on research progress of VFAs to PHA conversion and related enhancement techniques including optimization of operational parameters, fermentation strategies, and genetic engineering approaches. Finally, potential bottlenecks and future directions for the conversion of VFAs to PHA are outlined. This review offers insights to researchers on an integrated biorefinery route for sustainable and cost-effective bioplastics production.

scholarly journals INVESTIGATION OF ELECTROCHEMICAL COLOR REMOVAL FROM ORGANIZED INDUSTRIAL DISTRICT (OID) WASTEWATER TREATMENT PLANTS USING NEW GENERATION Sn/Sb/Ni-Ti ANODES

2018 ◽  
Vol 21 (2) ◽  
pp. 106-112
Keyword(s):  
Energy Consumption ◽  
Current Efficiency ◽  
Current Density ◽  
Wastewater Treatment Plants ◽  
Salt Content ◽  
Color Removal ◽  
Ozone Production ◽  
Ambient Conditions ◽  
Operational Parameters ◽  
Oxidation Efficiency

<p>In this study, the application of Sn/Sb/Ni-Ti electrodes for the treatment of waste streams were investigated which is promising for ozone production by electrolysis of water because of their stability and high potential for ozone evolution reaction. These series of anodes have a high electrochemical ozone generation potential at ambient conditions (approximately up to 40% current efficiency). But using and testing of these novel anodes for real wastewater are too limited in the literature. Titanium mesh substrate coated with Sn/Sb/Ni-Ti alloy was used as anode immersed in wastewater at room temperature with platinized titanium cathode. These electrodes used for COD and color removal from OID wastewater in Inegol, Bursa, Turkey. Five operational parameters were evaluated for electrochemical COD and color removal processes, such as pH, salt content, applied voltage/current, current efficiency and contact time. Experimental results showed that after 30 min the electrochemical oxidation efficiency of COD and color could reach up to 98% and 99% respectively at pH 8.2 and temperature of 25°C as the optimum conditions. Current density observed as the most effective parameter for COD and color removal efficiencies. The lowest energy consumption was between 10-25 mA cm-2 of current density with only 0.6 kWh gCOD−1, while the highest energy consumption was 100 mA cm-2 of current density with 9.12 kWh gCOD−1 . The optimum current density value has been found as 50 mA cm-2 with 4.05 kWh gCOD−1 . These results were also supported with ANOVA test.</p>

scholarly journals OPTIMIZATION OF THE USE OF THE PRODUCTION CAPACITY OF A SHIPYARD

2021 ◽  
pp. 89-107
Author(s):  
Olga Girina ◽  
◽  
Svetlana Zhigalovskaya ◽  
Keyword(s):  
Production Process ◽  
Production Capacity ◽  
Static Model ◽  
Test Case ◽  
Operational Parameters ◽  
Mathematical Methods ◽  
Production Program ◽  
Shipping Company ◽  
Ship Repair ◽  
Structure Of Production

The article discusses the issues of determining the production capacity of a shipyard and modeling the production process of ship repair using a systematic approach. The production capacity of the plant is understood as the maximum possible annual output in terms of the indicators and nomenclature established for the shipyard, with the full use of equipment and areas.The maximum volume of production is achieved when the structure of products is fully consistent with the structure of production resources and the structure of production assets. Improvement of management at the ship repair enterprise can be carried out in directions, including by creation of the model of production based on allocation of its most essential characteristics, used of mathematical methods of optimization. A static model is proposed to optimize the use of the shipyard production capacity, whenperforming scheduled preventive maintenance of shipping company ships in market conditions and a dynamic model of the annual plan in order to maximize the shipyard load and uniform use of its production capacity. In the performed calculations of the test case on the basis of the static model, four optimal plans with different optimization conditions were obtained: a plan for using the production capacity of theshipyard with the given initial data; plan with maximum production capacity with full use of shipyard resources; a plan for changing the solvency of the shipping company; plan for changing the terms and standards of ship repair. In all plans, the volume of repairs and the availability of resources limiting the production process are analyzed.Based on the proposed models, the following groups of factors on which the use of the production capacity of the shipyard depends have been identified:1) technical and operational parameters of shipyard units;2) demand for shipyard services in the form of volumes of planned work by type of production activity;3) standards for the use of shipyard capacities;4) the solvency of customers;5) the way of organizing the production process.The method of organizing ship repair is understood as fixing of certain resources of the shipyard units for the fulfillment of planned or additional customer orders. All factors of the first four groups affect the volume of ship repair and other indicators of the production program in termsthe actual or optimal way of organizing production.Key words: shipyard, production capacity, economic and mathematical models, analysis, grouping of factors

Aerobic biological treatment of grease from urban wastewater treatment plants

2001 ◽  
Vol 44 (2-3) ◽  
pp. 219-226 ◽  
Author(s):  
J. P. Canler ◽  
C. Royer ◽  
Ph. Duchène
Keyword(s):  
High Performance ◽  
Wastewater Treatment Plants ◽  
Data Interpretation ◽  
Operational Parameters ◽  
Detailed Measurement ◽  
Low Load ◽  
Volumetric Loading ◽  
Operating Constraints ◽  
Operational Constraints ◽  
Urban Wastewater Treatment

Biological grease treatment is rapidly expanding in France, with about sixty plants recorded in 1998. They are designed at a volumetric loading of 2.5 kg COD/m3 of reactor per day. Several sites have been selected for their representativity and studied. Prior to detailed monitoring over a long period, preliminary investigations provided some information on the operation of these reactors. They showed that most of them are not optimized (low removal efficiency), but have limited operational constraints given their low load. This study enabled us to assess the quantity actually skimmed from the surface of the aerated grease separator in relation to the lipids in raw sewage, and to define the precautions to be taken for sampling and analysis of grease, before any data interpretation. A detailed measurement series was then implemented. It shows the considerable value of this process for the reduction of lipids and highlights the main operational parameters in order to obtain high performance while keeping low operating constraints.

scholarly journals Eliminace mikropolutantů z vod kombinací oxidačních a sorpčních procesů v laboratorním měřítku

Entecho ◽  
2021 ◽  
Vol 4 (1) ◽  
pp. 15-20
Author(s):  
Tamara Pacholská ◽  
Ivan Karpíšek ◽  
Jana Zuzáková ◽  
Vojtěch Kužel ◽  
Stanislav Gajdoš ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Wastewater Treatment Plants ◽  
Granular Activated Carbon ◽  
Pilot Scale ◽  
Post Treatment ◽  
Operational Parameters ◽  
Activated Carbon Adsorption ◽  
Boron Doped Diamond ◽  
Carbon Adsorption ◽  
Wwtp Effluent

Mikropolutanty v životním prostředí působí negativně na vodní ekosystémy a též představují potenciální riziko pro lidské zdraví. Zásadním zdrojem vnosu mikropolutantů do životního prostředí jsou městské ČOV, jejichž konvenční mechanicko-biologická technologie není na odstraňování mikropolutantů navržena. V této práci jsme testovali účinnost odstranění mikropolutantů řadou oxidačních (např. ozonizace, UV/H2O2, Fentonova reakce, borem dopovaná diamantová elektroda) a sorpčních (např. granulované aktivní uhlí GAU, zeolity) procesů. Účinnost odstranění vybraných léčiv (např. erythromycin, sulfamethoxazol, ibuprofen atd.) a metabolitů pesticidů (např. acetochlor ESA, metazachlor ESA) jsme testovali v jednorázových vsádkových testech. S přihlédnutím k ekonomickým i provozním parametrům byla pro následné testování v reálných podmínkách (poloprovozní měřítko) zvolena kombinace oxidace UV/H2O2 a sorpce na GAU. Mikropolutanty v modelové vodě byly úspěšně odstraněny z 91% (suma léčiv) a cca 100% (suma metabolitů pesticidů) při použití optimální dávky H2O2 5 mg/l a intenzity UV záření 4 kJ/m2 s následnou sorpcí na GAU. Tyto velmi slibné výsledky v současné době ověřujeme v pilotní jednotce pro dočištění reálného odtoku z městské ČOV. Abstract (EN) Micropollutants cause harm to aquatic ecosystems and can also negatively affect human health. Major sources of micropollutants input to aquatic environments are wastewater treatment plants due to their insufficient removal during the conventional mechanical-biological process. This study aimed to evaluate potential WWTP effluent post-treatment processes for the removal of selected pharmaceuticals and pesticides using oxidation (e.g., ozonization, UV/H2O2, Fenton, boron-doped diamond electrode) and sorption (e.g. granular activated carbon, zeolite) processes and their combinations. The removal of selected pharmaceuticals (e.g. erythromycin, sulphamethoxazole, ibuprofen) and pesticides (e.g. acetochlor ESA, metazachlor ESA) was tested in batch assays. The combination of UV/H2O2 and activated carbon adsorption was the most favorable in terms of removal efficiency and economic and operational parameters. This combination achieved the removal efficiencies of pharmaceuticals and pesticides of 91 and 100%, respectively, using an optimum H2O2 dose of 5 mg/L and UV intensity of 4 kJ/m2 followed by granular activated carbon adsorption. These promising results are currently adopted in a pilot-scale study for the post-treatment of a real WWTP effluent.

scholarly journals Sustainable Wastewater Treatment Using Electrocoagulation Process Coupled With Powdered Activated Carbon

2021 ◽  
Author(s):  
Farooq Sher ◽  
Sania Zafar Iqbal ◽  
Tahir Rasheed ◽  
Kashif Hanif ◽  
Jasmina Sulejmanović ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Carbon ◽  
Pilot Plant ◽  
Wastewater Treatment Plants ◽  
Thermal Analyses ◽  
Powdered Activated Carbon ◽  
Volume Index ◽  
Electrochemical Technique ◽  
Operational Parameters ◽  
Sedimentation Tank

Abstract In this research an electrochemical technique in combination with powdered activated carbon (PAC) for the removal of micropollutants by adsorption as an advanced stage purification step from effluents of pilot plant wastewater treatment plants (WWTP). The effluents of sedimentation tank comprised of wastewater plus PAC (WWPAC). The pilot plant mainly consists of two parts; the first one consists of electrocoagulation (EC) reactor and the second consists of electrophoretic deposition (EPD) discs and electroflotation (EF) setup. The electrocoagulation (EC) reactor is a fiber box consisting of two chambers and thirty four plates of one material (either Fe or Al) on the whole in one EC reactor while one cell has seventeen plates. Both types of electrodes have been tested with the outflow of sedimentation tank. The outflow from the sedimentation tank has been entered into the EC reactor for the determination of EC reactor efficacy for the successful accomplishment of EC process at the designed pilot plant for WW treatment. The effect of different operational parameters; PAC dosage (20 mg), electrode nature (Fe and Al), current density (0.34–2.02 A/m2) has been studied to find out the optimum conditions. Sludge volume index (SVI) of the sludge, thermogravimetric (TG), differential thermal analyses (DTA) and particle size distribution (PSD) of the flocs generated after the EC process has also been studied. The turbidity, pH and conductivity of effluents before and after EC treatment has also been carried out. This pilot plant research gave promising results for future work in advance wastewater treatment direction.

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