Nitrogen is considered to be one of the most widespread pollutants leading to eutrophication of freshwater ecosystems, especially in drinking water reservoirs. In this study, an oligotrophic aerobic denitrifier was isolated from drinking water reservoir sediment. Nitrogen removal performance was explored. The strain was identified by 16S rRNA gene sequence analysis as Zoogloea sp. N299. This sp...

Problem statement: The activated sludge system is a complex dynamic process and must account for a large number of reactions between large numbers of components. There is necessity for simulation models which describe the dynamic behavior of the activated sludge process. The application of the models in most treatment plants is limited due to lack of appropriate data acquisition and parameters ...

Ammonia occurs in marine waters including effluents, receiving waters, and sediment interstitial waters. At sufficiently high concentrations, ammonia can be toxic to aquatic species. Toxicity identification evaluation (TIE) methods provide researchers with tools for identifying aquatic toxicants. For identifying ammonia toxicity, there are several possible methods including pH alteration and vo...

Previous work with leaching of metals from several fly ashes (both class F and class C) indicated minimal potential of leaching of toxic levels of metals from most fly ashes tested. Also, mixing fly ash with soil and other amendments (phosphate fertilizer) significantly decreases Cr, Li, Pb, and Cd in the leachate. One concern is that the characteristics of fly ash may be changed by the additio...

Many of the current greenhouse based intensive marine shrimp production systems have used photoautotrophic algae systems to control inorganic nitrogen accumulation. A second strategy of nitrogen control used in some indoor intensive recirculating production systems is using large fixed-film bioreactors. This option utilizes chemosynthetic autotrophic bacteria, Ammonia Oxidizing Bacteria (AOB) a...

Ammonia (NH3) emission from animal feeding operations (AFOs) has caused concerns on public health and environmental degradation, such as ecosystem acidification, eutrophication, and formation of PM2.5 fine particles. Current ammonia emission measurement methodologies are accurate and reliable, but time consuming, expensive, and impractical for most facilities. In the present study, an alternati...

Marshall’s1 urease method, in the modification proposed by Van Slyke and Cullen, is apparently the most accurate method available for the determination of urea. The method has, however, not yet attained the maximal degree of accuracy to be expected from volumetric processes in general. From the published figures of Van Slyke and Cullen, their modification appears to yield duplicates agreeing wi...

This study aimed to investigate the effects of carbon availability and intermittent aeration on nitrogen removal in a Sequencing Batch Biofilm Reactor (SBBR). The percentage of nitrogen removal in the SBBRs operating with dump fill and slow fill with optimum intermittent aeration was quite similar, 75.7% and 69.2%, respectively, indicating that intermittent aeration allowed a considerable energ...

This paper presents the experimental results obtained during the irradiation process with electron beam of flue gases generated by burning fuel with a high content in sulphur. The ALIN-10 accelerator was used for generating the electron beam. The necessary water was sprayed into the gaseous mixture as fine droplets by the mist pump. The highest removal efficiencies were obtained in the presence...

−A packed bed external loop airlift bioreactor (PBELAB) was proposed as an alternative treatment system for wastewater containing ammonia and nitrate compounds. The 60L PBELAB consisted of aeration and non-aeration zones, both of which were packed with plastic bioballs to enhance the surface area for the attachment of bacteria. The system was able to achieve complete removal of all nitrogen com...