Bioflocculants mediate the removal of suspended particles from solution and the efficiency of flocculation is dependent on the characteristics of the flocculant. Apart from the merits of biodegradability and harmlessness, bioflocculants could be viable as industrially relevant flocculants as they are a renewable resource. Additionally, the shortcomings associated with the conventionally used flocculants such as aluminium salts and acrylamide polymers, which include dementia and cancer, highlight more the need to use bioflocculants as an alternative. Consequently, in this study a marine sediment bacterial isolate was screened for bioflocculant production. Basic local alignment search tools (BLAST) analysis of 16S ribosomal deoxyribonucleic acid (rDNA) sequence of the bacterial isolate showed 98% similarity to MR-R1. The bacteria produced bioflocculant optimally with inoculum size (4% ) (85%), glucose (85.65%) and mixed nitrogen source (urea, ammonium chloride and yeast extract) (75.9%) and the divalent cation (Ca) (62.3%). Under optimal conditions, a maximum flocculating activity of over 85% was attained after 60 h of cultivation. The purified polysaccharide-bioflocculant flocculated optimally at alkaline pH 12 (81%), in the presence of Mn (73%) and Ca (72.8%). The high flocculation activity shown indicates that the bioflocculant may contend favourably as an alternative to the conventionally used flocculants in water treatment.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5664650 | PMC |
http://dx.doi.org/10.3390/ijerph14101149 | DOI Listing |
Rapid sand filters are established and widely applied technologies for groundwater treatment. In these filters, main groundwater contaminants such as iron, manganese, and ammonium are oxidized and removed. Conventionally, intensive aeration is employed to provide oxygen for these redox reactions.
View Article and Find Full Text PDFWater Res
June 2024
Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. Electronic address:
Inorganic coagulants such as poly aluminum ferric chloride (Al/Fe) are applied conventionally to sewage sludge dewatering and can be retained in the sludge cake, causing its conductivity to increase and generate secondary pollution. To reduce these disadvantages, there is a need to develop alternative, more sustainable chemicals as substitutes for conventional inorganic coagulants. In the present investigation, the application of a polymeric chitosan quaternary ammonium salt (CQAS) is explored as a complete, or partial, replacement for Al/Fe in the context of sludge dewatering processes.
View Article and Find Full Text PDFWater Sci Technol
February 2024
Institute for Sanitary Engineering, Water Quality and Solid Waste Management (ISWA), University of Stuttgart, Bandtäle 2, 70569 Stuttgart, Germany.
In the pursuit of a treatment approach that is both cost-effective and environmental-friendly, the applicability of microscreen (MS) techniques coupled with a primary sedimentation tank (PST) as a physical advanced primary treatment (APT) to enhance the removal of particulate organic carbon (POC) from municipal wastewater was investigated. A pilot unit, including a modified MS, adjustable to different meshes (including 20 and 15 μm) was operated continuously downstream to the PST at the Büsnau wastewater treatment plant in Stuttgart, Germany, and monitored for more than half a year. A strategy involving time-dependent backwashing and recirculation of MS permeate was employed to remove as much POC as possible from primarily treated wastewater, thereby extending the application of the MS.
View Article and Find Full Text PDFMethodsX
December 2022
School of Geography, Queen Mary University of London, London, UK, E1 4NS.
Flocculated suspended sediments (flocs) are found in a variety of environments globally, and their transport and behavior bear substantial importance to several industries including fisheries, aquaculture, and shipping. Additionally, the modelling of their behavior is important for estuarine and coastal flood prediction and defence, and the process of flocculation occurs in other unrelated industries such as paper and chemical production. Floc porosity is conventionally assessed using inferential indirect or proxy data approaches.
View Article and Find Full Text PDFWater Res
September 2021
Faculty of Engineering, Hokkaido University, N13W8, Sapporo 060-8628, Japan.
One of the main purposes of drinking water treatment is to reduce turbidity originating from clay particles. Relatively little is known about the removal of other types of particles, including conventionally sized powdered activated carbon (PAC) and superfine PAC (SPAC), which are intentionally added during the treatment process; microplastic particles; and viruses. To address this knowledge gap, we conducted a preliminary investigation in full-scale water treatment plants and then studied the removal of these particles during coagulation-flocculation, sedimentation, and rapid sand filtration (CSF) in bench-scale experiments in which these particles were present together.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!