Investigation of operational parameters for retaining properties of micro-plastics for typical aerobic wastewater treatment unit

2021 ◽  
pp. 130254
Author(s):  
Feilin Hao ◽  
Mingwei Shen
2005 ◽  
Vol 51 (10) ◽  
pp. 211-219 ◽  
Author(s):  
N. Oyama ◽  
J. Nair ◽  
G.E. Ho

An alternative method to conserve water and produce crops in arid regions is through hydroponics. Application of treated wastewater for hydroponics will help in stripping off nutrients from wastewater, maximising reuse through reduced evaporation losses, increasing control on quality of water and reducing risk of pathogen contamination. This study focuses on the efficiency of treated wastewater from an on-site aerobic wastewater treatment unit. The experiment aimed to investigate 1) nutrient reduction 2) microbial reduction and 3) growth rate of plants fed on wastewater compared to a commercial hydroponics medium. The study revealed that the chemical and microbial quality of wastewater after hydroponics was safe and satisfactory for irrigation and plant growth rate in wastewater hydroponics was similar to those grown in a commercial medium.


Author(s):  
G. Variushina

Приводятся сведения об условиях формирования, объемах, химическом составе и свойствах осадков очистных сооружений производственных сточных вод автотранспортных предприятий. Даны примеры технологических решений по обезвоживанию образующихся в процессе очистки шламов. Рассмотрены технологические аспекты процесса интенсификации механического обезвоживания уплотненных осадков с использованием высокомолекулярных полиэлектролитов. Представлены данные лабораторных экспериментов по выбору типа флокулянта, его дозы, технологических параметров процесса, а также результаты определения влажности обезвоженных осадков, полученные на модели барабанного вакуум-фильтра. Приведены примеры эффективных обезвоживающих аппаратов отечественного производства и их технические характеристики, рекомендации и критерии их выбора, а также факторы, оказывающие влияние на эксплуатационные параметры обезвоживающего оборудования. Установлено, что наилучшая обезвоживающая способность барабанных вакуум-фильтров (остаточная влажность шламов от 66 до 83) может быть достигнута при применении катионного флокулянта ВПК-402 для осадков различных производственных цехов автотранспортного предприятия.Information on the conditions of generation, volumes, chemical composition and properties of sludge generated at the industrial wastewater treatment facilities of motor transport enterprises is provided. Examples of process engineering solutions for dewatering sludge generated during the wastewater treatment process are given. The technological aspects of enhancing mechanical dewatering of thickened sludge using high-molecular polyelectrolytes are considered. The data of laboratory experiments on choosing the type of flocculant, its dose, technological parameters of the process, as well as the results of determining the moisture content of dewatered sludge obtained in a model of a drum vacuum filter are presented. Examples of effective domestically produced dewatering apparatus and their technical characteristics, recommendations and criteria for their selection, as well as factors influencing the operational parameters of the dewatering equipment are given. It is found that the highest dewatering capacity of drum vacuum filters (residual sludge moisture content from 66 to 83) can be achieved by using VPK-402 cationic flocculant for processing sludge generated at the workshop premises of a motor transport enterprise.


1990 ◽  
Vol 22 (7-8) ◽  
pp. 153-160 ◽  
Author(s):  
Pradeep Kumar ◽  
R. J. Garde

With increasing stress on existing wastewater treatment systems, it is necessary either to upgrade the treatment unit(s) or install an entirely new treatment plant. Obviously, the upgrading is preferred over the alternative of having a new system. Keeping this in view, in the present project, an attempt has been made to explore the possibility of upgrading existing facultative ponds using water hyacinth. Bench-scale batch studies were designed to compare the performance of hyacinth treatment system with facultative ponds. Investigations were carried out with synthetic wastewater having COD in the range of 32.5-1090 mg/l. The efficiency of COD removal in water hyacinth ponds was 15-20 percent more than the facultative ponds. Based on the results, an empirical model has been proposed for COD removal kinetics. In the second phase of the project a hyacinth pond was continuously operated. BOD, COD, TS, TN, TP, pH, and DO were regularly monitored. However, the DO of the effluent from hyacinth treatment system was considerably reduced. Effluent should be aerated before it is discharged. The results indicate that the existing facultative ponds can be stalked with water hyacinth to improve their performance as well as hyacinth treatment systems can be installed to support the conventional treatment.


2011 ◽  
Vol 1 (1) ◽  
pp. 37-56 ◽  
Author(s):  
Sílvia C. Oliveira ◽  
Marcos von Sperling

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.


1993 ◽  
Vol 28 (7) ◽  
pp. 139-142 ◽  
Author(s):  
J. Chang ◽  
P. Chudoba ◽  
B. Capdeville

Maintenance energy plays an important role both in basic kinetic studies and in process development. Numerous studies have been devoted to the maintenance concept in various microbial fields but very few in biological wastewater treatment. Using a fermenter coupled to a mass spectrometer, we investigated the influence of the ratio So/Xo (ratio between initial substrate concentration and initial biomass concentration) on the observed sludge growth yield of an oxic-settling anaerobic (OSA) system. By measuring the substrate removed, the oxygen consumed and the carbon dioxide produced, we were able to estimate the substrate fraction used for maintenance purposes. The results indicate that at a high So/Xo ratio, a greater proportion of the substrate is devoted to maintenance thus significantly decreasing the observed growth yield. These findings are of particular importance in view of the cost associated with the disposal of excess sludge in aerobic wastewater treatment processes.


2003 ◽  
Vol 6 (1) ◽  
pp. 66-72 ◽  
Author(s):  
A. Gangagni Rao ◽  
K. Krishna Prasad ◽  
G. Venkata Naidu ◽  
N. Chandrashekar Rao ◽  
P. N. Sarma

2018 ◽  
Vol 85 (5) ◽  
Author(s):  
Veronica R. Brand ◽  
Laurel D. Crosby ◽  
Craig S. Criddle

ABSTRACTMultiple clades within a microbial taxon often coexist within natural and engineered environments. Because closely related clades have similar metabolic potential, it is unclear how diversity is sustained and what factors drive niche differentiation. In this study, we retrieved three near-complete Competibacter lineage genomes from activated sludge metagenomes at a full-scale pure oxygen activated sludge wastewater treatment plant. The three genomes represent unique taxa within theCompetibacteraceae. A comparison of the genomes revealed differences in capacity for exopolysaccharide (EPS) biosynthesis, glucose fermentation to lactate, and motility. Using quantitative PCR (qPCR), we monitored these clades over a 2-year period. The clade possessing genes for motility and lacking genes for EPS biosynthesis (CPB_P15) was dominant during periods of suspended solids in the effluent. Further analysis of operational parameters indicate that the dominance of the CPB_P15 clade is associated with low-return activated sludge recycle rates and low wasting rates, conditions that maintain relatively high levels of biomass within the system.IMPORTANCEMembers of the Competibacter lineage are relevant in biotechnology as glycogen-accumulating organisms (GAOs). Here, we document the presence of threeCompetibacteraceaeclades in a full-scale activated sludge wastewater treatment plant and their linkage to specific operational conditions. We find evidence for niche differentiation among the three clades with temporal variability in clade dominance that correlates with operational changes at the treatment plant. Specifically, we observe episodic dominance of a likely motile clade during periods of elevated effluent turbidity, as well as episodic dominance of closely related nonmotile clades that likely enhance floc formation during periods of low effluent turbidity.


Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2764
Author(s):  
Argyro Plevri ◽  
Klio Monokrousou ◽  
Christos Makropoulos ◽  
Christos Lioumis ◽  
Nikolaos Tazes ◽  
...  

Water reuse and recycling is gaining momentum as a way to improve the circularity of cities, while recognizing the central role of water within a circular economy (CE) context. However, such interventions often depend on the location of wastewater treatment plants and the treatment technologies installed in their premises, while relying on an expensive piped network to ensure that treated wastewater gets transported from the treatment plant to the point of demand. Thus, the penetration level of treated wastewater as a source of non-potable supply in dense urban environments is limited. This paper focuses on the demonstration of a sewer mining (SM) unit as a source of treated wastewater, as part of a larger and more holistic configuration that examines all three ‘streams’ associated with water in CE: water, energy and materials. The application area is the Athens Plant Nursery, in the (water stressed) city of Athens, Greece. SM technology is in fact a mobile wastewater treatment unit in containers able to extract wastewater from local sewers, treat it directly and reuse at the point of demand even in urban environments with limited space. The unit consists of a membrane bioreactor unit (MBR) and a UV disinfection unit and produces high quality reclaimed water for irrigation and also for aquifer recharge during the winter. Furthermore, a short overview of the integrated nutrient and energy recovery subsystem is presented in order to conceptualise the holistic approach and circularity of the whole configuration. The SM technology demonstrates flexibility, scalability and replicability, which are important characteristics for innovation uptake within the emerging CE context and market.


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