Physico-chemical and biological treatment strategies for converting municipal wastewater and its residue to resources

Chemosphere ◽  
2021 ◽  
pp. 130881
Author(s):  
Asfak Patel ◽  
Ambika Arkatkar ◽  
Srishti Singh ◽  
Alija Rabbani ◽  
Juan David Solorza Medina ◽  
...  
1991 ◽  
Vol 24 (7) ◽  
pp. 285-292 ◽  
Author(s):  
F. A. El-Gohary ◽  
S. I. Abo-Elela ◽  
S. A. Shehata ◽  
H. M. El-Kamah

Physico-chemical sewage treatment via coagulation-sedimentation is put in action for suspended solids removal. The effectiveness of this technology concerning the soluble organic content is extremely low. In direct comparison, the use of a biological sand-bed and a high-rate oxidation pond as a tertiary treatment for the chemically treated effluent brought about a substantial increase in efficiency. Experimental investigations performed led to the conclusions that, for the reuse of wastewater for irrigation, chemical treatment is appropriate. For discharge of treated effluents into surface water, combination of the physico-chemical-biological scheme is recommended.


2003 ◽  
Vol 3 (4) ◽  
pp. 145-152 ◽  
Author(s):  
H. Heinonen-Tanski ◽  
P. Juntunen ◽  
R. Rajala ◽  
E. Haume ◽  
A. Niemelä

Municipal treated wastewater has been tertiary treated in a pilot-scale rapid sand filter. The filtration process was improved by using polyaluminium coagulants. The sand-filtered water was further treated with one or two UV reactors. The quality changes of wastewater were measured with transmittance, total phosphorus, soluble phosphorus, and somatic coliphages, FRNA-coliphages, FC, enterococci and fecal clostridia. Sand filtration alone without coagulants improved slightly some physico-chemical parameters and it had almost no effect on content of microorganisms. If coagulants were used, the filtration was more effective. The reductions were 88-98% for microbial groups and 80% for total phosphorus. The wastewater would meet the requirements for bathing waters (2,000 FC/100 ml, EU, 1976). UV further improved the hygiene level; this type of treated wastewater could be used for unrestricted irrigation (2.2 TC/100 ml, US.EPA 1992). The improvement was better if coagulants were used. The price for tertiary treatment (filtration + UV) would have been 0.036 Euro/m3 according to prices in 2001 in 22 Mm3/a. The investment cost needed for the filtration unit was 0.020 Euro/m3 (6%/15a). Filtration with coagulants is recommended in spite of its costs, since the low transmittance of unfiltered wastewater impairs the efficiency of the UV treatment.


Rheumatology ◽  
2021 ◽  
Author(s):  
Cécile Gaujoux-Viala ◽  
Christophe Hudry ◽  
Elena Zinovieva ◽  
Hélène Herman-Demars ◽  
René-Marc Flipo

Abstract Objectives The STRATEGE study aimed to describe treatment strategies in current practice in RA bDMARD-naive patients with an inadequate response to MTX therapy, and to compare clinical efficacy of the different therapeutic strategies on disease activity after six months. Methods Main inclusion criteria of this prospective, observational, multicentre study were confirmed RA diagnosis, treatment by MTX monotherapy, and need for therapeutic management modification. Results The 722 patients included had a mean (S.D.) RA duration of 5.3 (6.7) years, a mean DAS28 of 4.0 (±1.1); they were all receiving MTX monotherapy, 68% oral, at a mean dose of 15.0 (4.1) mg/wk. Two major strategies were identified: (i) MTX monotherapy dose and/or route optimization (72%) and (ii) bDMARD initiation ± MTX (16%). MTX dosing was modified for 70% of patients, maintained (dose and route) for 28% of patients, and interrupted for 2%. bDMARDs were started when the MTX mean dose was 17.4 mg/wk, 56% parenterally; MTX was maintained concomitantly for 96% of patients. Six-month follow-up results adjusted by propensity score showed that both options were equally successful in improving disease activity and physical function, with 63% and 68% of good-to-moderate EULAR responses, respectively. Conclusion The STRATEGE study shows the importance of initial MTX treatment optimization before initiation of a biological treatment and emphasizes the importance of treat-to-target strategy.


2018 ◽  
Vol 78 (3) ◽  
pp. 644-654 ◽  
Author(s):  
J. Olsson ◽  
S. Schwede ◽  
E. Nehrenheim ◽  
E. Thorin

Abstract A mix of microalgae and bacteria was cultivated on pre-sedimented municipal wastewater in a continuous operated microalgae-activated sludge process. The excess material from the process was co-digested with primary sludge in mesophilic and thermophilic conditions in semi-continuous mode (5 L digesters). Two reference digesters (5 L digesters) fed with waste-activated sludge (WAS) and primary sludge were operated in parallel. The methane yield was slightly reduced (≈10%) when the microalgal-bacterial substrate was used in place of the WAS in thermophilic conditions, but remained approximately similar in mesophilic conditions. The uptake of heavy metals was higher with the microalgal-bacterial substrate in comparison to the WAS, which resulted in higher levels of heavy metals in the digestates. The addition of microalgal-bacterial substrate enhanced the dewaterability in thermophilic conditions. Finally, excess heat can be recovered in both mesophilic and thermophilic conditions.


2015 ◽  
Vol 89 (1) ◽  
pp. 122-127 ◽  
Author(s):  
Cristina Mariana Nastasă ◽  
Mihaela Duma ◽  
Adrian Pîrnău ◽  
Laurian Vlase ◽  
Brîndușa Tiperciuc ◽  
...  

Background and aims. In the context of the increasing phenomenon of microbial resistance to usual drugs, the development of new treatment strategies and new therapeutic protocols is a constant need. Thiazolidinedione and chromone represent two important scaffolds in medicinal chemistry due to their large pharmacological applicability.Methods. We synthesized a new 5-(chromene-3-yl)methylene-2,4-thiazolidinedione starting from 6,8-dichloro-4-oxo-4H-chromene-3-carbaldehyde. Then, by treating with different α-bromoalkylarylketones, we obtained N-substituted derivatives. All new compounds were investigated for their antimicrobial potential, using the diffusion method, against Listeria monocytogenes ATCC 13932, Staphylococcus aureus ATCC 49444, Escherichia coli ATCC 25922, Salmonella typhimurium ATCC 14028 and Candida albicans ATCC 10231. Three concentrations, 10 mg/ml, 5 mg/ml and 1 mg/ml of compounds were used. The results were evaluated by the measurement of the inhibition zone diameters and compared to those of gentamicin and fluconazole respectively, as reference drugs.Results. All new synthesized compounds were characterized using physico-chemical and spectrometric methods. They displayed modest to good antimicrobial activity. New molecules 8, 9 and 10 may represent promising candidates, showing zone inhibition diameters superior to those of reference drugs.Conclusions. This work presents chemical synthesis, characterization and investigation of the antibacterial and antifungal potential of 5-(chromene-3-yl)methylene-2,4-thiazolidinedione derivatives, which may be worthy of future research for designing new chemical entities.


2018 ◽  
Vol 39 (1_suppl) ◽  
pp. 9S-15S ◽  
Author(s):  
Malcolm E. Dombrowski ◽  
Youichi Yasui ◽  
Christopher D. Murawski ◽  
Lisa A. Fortier ◽  
Eric Giza ◽  
...  

Background: The evidence supporting best practice guidelines in the field of cartilage repair of the ankle are based on both low quality and low levels of evidence. Therefore, an international consensus group of experts was convened to collaboratively advance toward consensus opinions based on the best available evidence on key topics within cartilage repair of the ankle. The purpose of this article is to report the consensus statements on “Conservative Management and Biological Treatment Strategies” developed at the 2017 International Consensus Meeting on Cartilage Repair of the Ankle. Methods: Seventy-five international experts in cartilage repair of the ankle representing 25 countries and 1 territory were convened and participated in a process based on the Delphi method of achieving consensus. Questions and statements were drafted within 11 working groups focusing on specific topics within cartilage repair of the ankle, after which a comprehensive literature review was performed and the available evidence for each statement was graded. Discussion and debate occurred in cases where statements were not agreed upon in unanimous fashion within the working groups. A final vote was then held, and the strength of consensus was characterized as follows: consensus, 51% to 74%; strong consensus, 75% to 99%; unanimous, 100%. Results: A total of 12 statements on Conservative Management and Biological Treatment Strategies reached consensus during the 2017 International Consensus Meeting on Cartilage Repair of the Ankle. Ten statements reached strong consensus (greater than 75% agreement), and 2 achieved consensus. Conclusions: This international consensus derived from leaders in the field will assist clinicians with conservative management and biological treatment strategies for osteochondral lesions of the talus.


2022 ◽  
Vol 11 (6) ◽  
pp. 667-675
Author(s):  
Amina-Afaf MOUFFAK

Furfural is one of the petroleum products posing a potential danger to the environment and human health. However, the decontamination of these pollutants released into the environment is primarily governed by biodegra-dation processes. This study is based on biodegradation kinetics at increasing concentrations of furfural by natural mixed culture in order to assess the potential of this process in the elimination of furfural from petrochemical effluents from the ARZEW refinery. This biodegradation was measured through physicochemical parameters such as pH, electrical conductivity, con-centration of hydrocarbons, the chemical oxygen demand (COD), biochemi-cal oxygen demand (BOD5) and the concentration of furfural. The results obtained show at a concentration of 250ppm of injected furfural: a decrease in pH 4.9 and an increase in other parameters (conductivity 3450 μS.cm-1, HC 102 mg / l; furfural 210 ppm, COD 327mg / l, BOD5 98mgO2 / l. The study findings indicated that the injection of these effluents with concentrations greater than 180 ppm leads to values of pH, EC, HC, Furfural, COD, BOD5 which do not comply with direct discharge standards and disrupt biological treatment. The high levels of furfural not only cause a pollution problem but can also disrupt the functioning of bacteria at the biological treatment level. Therefore, dilution with the filtration wash water before switching to biologi-cal treatment is recommended in order to reduce the concentrations below 180 ppm.


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