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The EPS Matrix of Aerobic Granular Sludge
Published in Y.V. Nancharaiah, Vayalam P. Venugopalan, Microbial Biofilms in Bioremediation and Wastewater Treatment, 2019
Y.V. Nancharaiah, M. Sarvajith, V.P. Venugopalan
Ammonium nitrogen is released to the environment through various activities such as production of chemical fertilizers, release of unutilized reactive nitrogen in the agricultural runoff, sewage and animal manure. Landfill leachate, human urine, swine liquor and liquor from anaerobic digester are some of the examples of ammonium rich waste streams. Ammonium and its transformation products such as nitrite and nitrate are collectively called as reactive nitrogen because such higher levels of ammonium and nitrite nitrogen are toxic to living organisms. Nitrate contamination of ground water is widespread and consumption of nitrate contaminant water is linked to blue baby syndrome in children (Fowler et al. 2013, Nancharaiah and Venugopalan 2011). Therefore, pollution of waters with reactive nitrogen is a public health issue. Additionally, release of reactive nitrogen to surface waters (i.e., ponds and lakes) is associated with excessive growth of algae and aquatic plants and eutrophication. Removal of reactive nitrogen from waste streams is necessary to protect public health and to avoid eutrophication of water bodies.
Sea: Pollution
Published in Brian D. Fath, Sven E. Jørgensen, Megan Cole, Managing Water Resources and Hydrological Systems, 2020
Eutrophication is an increase in chemical nutrients, typically compounds containing nitrogen or phosphorus, in an ecosystem. It can result in an increase in the ecosystem’s primary productivity (excessive plant growth and decay), and further effects, including lack of oxygen and severe reductions in water quality and in fish and other animal populations.[11] The biggest culprits are rivers that empty into the ocean, and along with it many chemicals used as fertilizers in agriculture as well as waste from livestock and humans. An excess of oxygen-depleting chemicals in the water can lead to hypoxia and the creation of a dead zone.[49–51] Estuaries tend to be naturally eutrophic because land-derived nutrients are concentrated where runoff enters the marine environment in a confined channel. The World Resources Institute has identified 375 hypoxic coastal zones around the world, concentrated in coastal areas in Western Europe, the eastern and southern coasts of the United States, and East Asia, particularly in Japan. In the ocean, there are frequent red tide algae blooms that kill fish and marine mammals and cause respiratory problems in humans and some domestic animals when the blooms reach close to shore.[52–54] In addition to land runoff, atmospheric anthropogenic nitrogen can enter the open ocean. A study in 2008 found that this could account for around one-third of the ocean’s external (non-recycled) nitrogen supply and up to 3% of the annual new marine biological production. It has been suggested that accumulating reactive nitrogen in the environment may have consequences as serious as putting carbon dioxide in the atmosphere.[54]
Introduction to Biodegradable Polymers
Published in Arbind Prasad, Ashwani Kumar, Kishor Kumar, Biodegradable Composites for Packaging Applications, 2023
Arbind Prasad, Gourhari Chakraborty, Ashwani Kumar, Kishor Kumar
A biodegradable carboxymethyl cellulose (CMC)-based material for sustainable packaging application was reported. A value-added product of biodegradable material for sustainable packaging was developed. Waste-derived CMC mainly reduces the cost involved in the development of the film; at present, commercially available CMC is costly. During this process, CMC was mainly extracted from agricultural wastes such as sugarcane bagasse and the blends were prepared using CMC (waste derived), gelatin, agar, and varied concentrations of glycerol. The resultant product was characterized and observed to be suitable for packaging applications [21]. Nitrogen pollution impact and remediation through low-cost starch-based biodegradable polymers was reported. It was mentioned that high urea inputs raise the level of reactive nitrogen in the soil, air, and water. Unused reactive nitrogen acts as a pollutant and harms the natural resources. The use of controlled-release fertilizers for slowing down the nutrients’ leaching has recently come into practice among farmers worldwide. The starches, modified with urea and borate, showed good stability and mechanical strength over time [22]. Biodegradable polymers for biomedical additive manufacturing were reported. The source of extraction, chemical modification, or synthesis route, and their physicochemical and processing properties in relationship to additive manufacturing were studied. Finally, it was discussed that biodegradable polymers can also play a vital role in the function of the materials as well as drug carriers [23]. Biodegradable polymers were used in conductive sensing applications, and it was observed that more enhanced properties were achieved, which could be more useful in the fabrication of conducting polymers and sensors [24].
How changing environments alter the microbial composition and ecological response in marine biofilms: a mini review
Published in Egyptian Journal of Basic and Applied Sciences, 2023
Marine nitrogen deposition involves the atmospheric input of reactive nitrogen into the marine environment. The process by which reactive nitrogen is transferred from the atmosphere to the ocean affects the pH, nutrient status and biofilm formation of the marine environment. Nitrogen is the most important element that tends to alter primary productivity of marine environment due to its crucial role in marine biogeochemistry and its interrelation with other biogeochemical cycles such as carbon cycle. In marine environment, nitrogen ranges in form from NH4 and NO3 which are in reduce form and fully oxidized form, respectively. This is the reason why nitrogen could act as both electron donor and acceptor in marine environment. The alteration of marine environment caused by GHGE tends to have negative effect on marine biota. It is thereby important to study the role of marine biofilm in marine nitrogen deposition. The marine nitrogen deposition process involves different microbial transformations, and enzymes are found in the organism forming marine biofilm. These processes of transformation of nitrogen compounds in the marine environment tend to have important effects on the stability of nitrogen in marine environment. The present study reports processes involved in marine nitrogen deposition and the role of marine biofilm in the process of nitrogen transformation and deposition. The present study is based on marine-fixed nitrogen, marine-retained nitrogen and marine loss nitrogen.
Fertilizer nitrogen loss via N2 emission from calcareous soil following basal urea application of winter wheat
Published in Atmospheric and Oceanic Science Letters, 2019
Yukun ZHANG, Rui WANG, Zhanlei PAN, Yan LIU, Xunhua ZHENG, Xiaotang JU, Chong ZHANG, Klaus BUTTERBACH-BAHL, Binxiang HUANG
Anthropogenic activities have dramatically increased the amount of reactive nitrogen (Nr) circulating in the biosphere and atmosphere, creating a series of environmental consequences, such as eutrophication, acidification, and air pollution (Fowler et al. 2013). Terrestrial denitrification converts 30%–60% of the Nr back into nitrogen gas (N2) (Ciais et al. 2013), and thus contributes to close the global nitrogen (N) cycle (Gruber and Galloway 2008). Moreover, denitrification is an important process of fertilizer N loss from agricultural systems (Bouwman et al. 2013), as it converts nitrate and nitrite into nitric oxide (NO), nitrous oxide (N2O), and N2. Among these gases, the N loss through N2 emission is especially most uncertain in terrestrial N budgets because the high background atmospheric N2 concentration makes soil N2 emissions difficult to measure (Davidson and Seitzinger 2006). This situation is greatly hampering accurate quantification of terrestrial N budgets using experimental or modeling approaches.
Influence of stormwater control measures on water quality at nested sites in a small suburban watershed
Published in Urban Water Journal, 2018
Rachel D. Scarlett, Sara K. McMillan, Colin D. Bell, Sandra M. Clinton, Anne J. Jefferson, P. Suresh C. Rao
Urban runoff has been identified as a significant cause of water quality impairment and degraded ecosystem function in receiving waters (e.g. Klein 1979; Meyer, Paul, and Taulbee 2005; O’Driscoll et al. 2010). In particular, excess reactive nitrogen (N) and phosphorus (P) from urban land uses contribute to eutrophication of rivers, lakes, and coastal estuaries (Carpenter et al. 1998; Howarth et al. 2000). Elevated instream concentrations of other anthropogenic pollutants, such as major ions, can be toxic to aquatic food webs (Clements and Kotalik 2016). Macroinvertebrate community structure is a function of salinity (Kefford 1998; Timpano et al. 2018); increased salinity causes stark declines in richness and abundance of sensitive taxa such as mayflies (Timpano et al. 2018). In particular, increased magnesium and sulfate concentrations correlate with a decrease in macroinvertebrate community metabolism (Clements and Kotalik 2016).