scholarly journals Using Oxidative Electrodes to Enrich Novel Members in the Desulfobulbaceae Family from Intertidal Sediments

2021 ◽  
Vol 9 (11) ◽  
pp. 2329
Author(s):  
Cheng Li ◽  
Clare E. Reimers ◽  
Yvan Alleau

Members in the family of Desulfobulbaceae may be influential in various anaerobic microbial communities, including those in anoxic aquatic sediments and water columns, and within wastewater treatment facilities and bioelectrochemical systems (BESs) such as microbial fuel cells (MFCs). However, the diversity and roles of the Desulfobulbaceae in these communities have received little attention, and large portions of this family remain uncultured. Here we expand on findings from an earlier study (Li, Reimers, and Alleau, 2020) to more fully characterize Desulfobulbaceae that became prevalent in biofilms on oxidative electrodes of bioelectrochemical reactors. After incubations, DNA extraction, microbial community analyses, and microscopic examination, we found that a group of uncultured Desulfobulbaceae were greatly enriched on electrode surfaces. These Desulfobulbaceae appeared to form filaments with morphological features ascribed to cable bacteria, but the majority were taxonomically distinct from recognized cable bacteria genera. Thus, the present study provides new information about a group of Desulfobulbaceae that can exhibit filamentous morphologies and respire on the oxidative electrodes. While the phylogeny of cable bacteria is still being defined and updated, further enriching these members can contribute to the overall understanding of cable bacteria and may also lead to identification of successful isolation strategies.

2020 ◽  
Vol 17 (3) ◽  
pp. 597-607 ◽  
Author(s):  
Cheng Li ◽  
Clare E. Reimers ◽  
Yvan Alleau

Abstract. Cable bacteria (CB) are multicellular, filamentous bacteria within the family of Desulfobulbaceae that transfer electrons longitudinally from cell to cell to couple sulfide oxidation and oxygen reduction in surficial aquatic sediments. In the present study, electrochemical reactors that contain natural sediments are introduced as a tool for investigating the growth of CB on electrodes poised at an oxidizing potential. Our experiments utilized sediments from Yaquina Bay, Oregon, USA, and we include new phylogenetic analyses of separated filaments to confirm that CB from this marine location cluster with the genus “Candidatus Electrothrix”. These CB may belong to a distinctive lineage, however, because their filaments contain smaller cells and a lower number of longitudinal ridges compared to cables described from other locales. The results of a 135 d bioelectrochemical reactor experiment confirmed that these CB can migrate out of reducing sediments and grow on oxidatively poised electrodes suspended in anaerobic seawater. CB filaments and several other morphologies of Desulfobulbaceae cells were observed by scanning electron microscopy and fluorescence in situ hybridization on electrode surfaces, albeit in low densities and often obscured by mineral precipitation. These findings provide new information to suggest what kinds of conditions will induce CB to perform electron donation to an electrode surface, further informing future experiments to culture CB outside of a sediment matrix.


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.


Author(s):  
G. Variushina

Приводятся сведения о разработанных специалистами АО МосводоканалНИИпроект научных исследованиях и проектных решениях в области очистки поверхностных сточных вод с территории Москвы, причинах загрязнения водоисточников неочищенными поверхностными стоками в 1970х годах. Представлены основные характеристики комплексов глубокой очистки поверхностных стоков, разработанных проектов очистных сооружений для промышленных предприятий с площадью водосбора 0,3 1 5 10 и 15 га. Показано, что эффективность очистки поверхностных сточных вод соответствует требованиям, предъявляемым к водоемам рыбохозяйственного значения. При этом для обезвоживания осадка, образующегося в накопительном резервуаре очистных сооружений, в технологической схеме предусмотрена песковая площадка, а для сбора плавающих нефтепродуктов нефтеразделитель. Новизна разработанной технологии обезвреживания поверхностного стока и обработки осадка была подтверждена пятью патентами РФ, одобрена Госстроем РФ, Центральным управлением по рыбохозяйственной экспертизе и нормативам по сохранению, воспроизводству водных биологических ресурсов и акклиматизации, Городской санитарной службой Москвы и области, службами Москомприроды и Мосгосэкспертизы. Показан вклад специалистов лаборатории обработки природных, промышленнодождевых сточных вод и осадка в решение проблем очистки поверхностного стока. Приведена информация об истории развития и перспективных направлениях научной деятельности лаборатории, ее планах в организационнометодической и воспитательной работе с молодыми специалистами.Information on the research and design solutions developed by the experts of MosvodokanalNIIproject JSC in the field of surface runoff treatment from the territory of Moscow, the causes of water sources pollution with raw surface runoff in the 1970s. The basic characteristics of the complexes for the enhanced treatment of surface runoff, the developed projects of wastewater treatment facilities for industrial enterprises with a catchment area of 0.3 1 5 10 and 15 ha. It is shown that the effectiveness of surface runoff treatment meets the requirements to water bodies of commercial fishing importance. At the same time, for dewatering of sludge generated in the retention basin of wastewater treatment facilities, a grit dewatering bay is included into the process flow scheme, and an oil separator is used to collect floating oil products. The novelty of the developed technology for neutralization of surface runoff and sludge treatment has been acknowledged by five patents of the Russian Federation, approved by Gosstroy of the Russian Federation, the Central Department of Fisheries Examination and Review and Protection and Renewal and Acclimatization Standards, the Moscow City and Moscow Region Sanitary Service, Moskompriroda and Mosgosekspertiza services. The contribution of the research workers of the laboratory for the treatment of natural, industrialstorm wastewater and sludge processing to the solution of problems of surface runoff treatment is demonstrated. The information about the history of development and promising areas of research activity of the laboratory, its plans in the organizational, methodological and educational work with young professionals is given.


1993 ◽  
Vol 27 (12) ◽  
pp. 205-208
Author(s):  
Dirk-Th Kollatsch

For upgrading the urban drainage system (UDS) the reduction of pollution impacts is the priority task concerning the environmental protection of the receiving waters. With simulation models the interactions between surface, sewer systems, overflow structures and treatment facilities within the UDS can be shown. Models to simulate the pollutant impacts, transport and the effects on the receiving waters are available. In a first step a pollutant transport model of sewer systems and a model to simulate the wastewater treatment processes are connected. With these models the efficiency of upgrading measures can be checked in all parts of urban drainage systems.


2017 ◽  
Vol 2017 (6) ◽  
pp. 4930-4947 ◽  
Author(s):  
Steven Hanna ◽  
Bruce Dvorak ◽  
Mohamed Dahab ◽  
Matthew Thompson

2021 ◽  
Vol 775 ◽  
pp. 145904
Author(s):  
Jaecheul Yu ◽  
Younghyun Park ◽  
Evy Widyaningsih ◽  
Sunah Kim ◽  
Younggy Kim ◽  
...  

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