The Malachite Green Biodegradation in Bioreactors on Various pH Domains

2019 ◽  
Vol 70 (8) ◽  
pp. 2996-2999
Author(s):  
Viorel Gheorghe ◽  
Catalina Gabriela Gheorghe ◽  
Andreea Bondarev ◽  
Vasile Matei ◽  
Mihaela Bombos

In the experimental study was studied the malachite green colorant biodegradation in biological sludge with biological activity. The biodegradability tests were carried out in laboratory bioreactors, on aqueous solutions of green malachite contacted with microorganisms in which the dominant species is Paramecium caudatum, in a pH range between 8 and 12, temperatures in the ranges 25-350C, using pH neutralizing substances and biomass growth promoters. The colorant initial concentrations and those obtained after biological degradation depending on the contact time, at certain pH values, were established through UV-Vis spectrometry. The studies have shown the measure of possible biological degradation of some organic substances with extended uses, with largely aromatic structure, resistance to biodegradation of microorganisms, commonly used in wastewater treatment plants.

2008 ◽  
Vol 3 (1) ◽  
Author(s):  
Luchien Luning ◽  
Paul Roeleveld ◽  
Victor W.M. Claessen

In recent years new technologies have been developed to improve the biological degradation of sewage sludge by anaerobic digestion. The paper describes the results of a demonstration of ultrasonic disintegration on the Dutch Wastewater Treatment Plant (WWTP) Land van Cuijk. The effect on the degradation of organic matter is presented, together with the effect on the dewatering characteristics. Recommendations are presented for establishing research conditions in which the effect of sludge disintegration can be determined in a more direct way that is less sensitive to changing conditions in the operation of the WWTP. These recommendations have been implemented in the ongoing research in the Netherlands supported by the National Institute for wastewater research (STOWA).


Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 590
Author(s):  
Aiban Abdulhakim Saeed Ghaleb ◽  
Shamsul Rahman Mohamed Kutty ◽  
Gasim Hayder Ahmed Salih ◽  
Ahmad Hussaini Jagaba ◽  
Azmatullah Noor ◽  
...  

Man-made organic waste leads to the rapid proliferation of pollution around the globe. Effective bio-waste management can help to reduce the adverse effects of organic waste while contributing to the circular economy at the same time. The toxic oily-biological sludge generated from oil refineries’ wastewater treatment plants is a potential source for biogas energy recovery via anaerobic digestion. However, the oily-biological sludge’s carbon/nitrogen (C/N) ratio is lower than the ideal 20–30 ratio required by anaerobic digestion technology for biogas production. Sugarcane bagasse can be digested as a high C/N co-substrate while the oily-biological sludge acts as a substrate and inoculum to improve biogas production. In this study, the best C/N with co-substrate volatile solids (VS)/inoculum VS ratios for the co-digestion process of mixtures were determined empirically through batch experiments at temperatures of 35–37 °C, pH (6–8) and 60 rpm mixing. The raw materials were pre-treated mechanically and thermo-chemically to further enhance the digestibility. The best condition for the sugarcane bagasse delignification process was 1% (w/v) sodium hydroxide, 1:10 solid-liquid ratio, at 100 °C, and 150 rpm for 1 h. The results from a 33-day batch anaerobic digestion experiment indicate that the production of biogas and methane yield were concurrent with the increasing C/N and co-substrate VS/inoculum VS ratios. The total biogas yields from C/N 20.0 with co-substrate VS/inoculum VS 0.06 and C/N 30.0 with co-substrate VS/inoculum VS 0.18 ratios were 2777.0 and 9268.0 mL, respectively, including a methane yield of 980.0 and 3009.3 mL, respectively. The biogas and methane yield from C/N 30.0 were higher than the biogas and methane yields from C/N 20.0 by 70.04 and 67.44%, respectively. The highest biogas and methane yields corresponded with the highest C/N with co-substrate VS/inoculum VS ratios (30.0 and 0.18), being 200.6 mL/g VSremoved and 65.1 mL CH4/g VSremoved, respectively.


2021 ◽  
pp. 0734242X2110284
Author(s):  
Maria Rosaria Boni ◽  
Alessandra Polettini ◽  
Raffaella Pomi ◽  
Andreina Rossi ◽  
Alessandro Filippi ◽  
...  

The Circular and Green Economy principles is inspiring new approaches to municipal wastewater treatment plants (MWWTPs) design and operation. Recently, an ever-growing interest is devoted to exploring the alternatives for switching the WWTPs from being able to ‘simply’ removing contaminants from water to biorefinery-like plants where energy and material can be recovered. In this perspective, both wastewater and residues from process can be valorised for recovering nutrients (N and P), producing value added products (i.e. biopolymers), energy vectors and biofuels (i.e. bio-H2, bio-CH4 and bioethanol). As an additional benefit, changing the approach for WWTPs design and operation will decrease the overall amount of landfilled residues. In this context, the present research is aimed at evaluating the CH4 production potential of MWW screening units’ residues. While such a stream is typically landfilled, the expected progressive increase of biodegradable matter content due to the ban on single-use plastic along with the boost of bioplastics makes the investigation of different biochemical valorisation routes more and more interesting from an environmental and economical perspective. Thus, a full-scale data collection campaign was performed to gain information on screening residues amount and properties and to analyse the relationship with influent flowrate. The most relevant residue properties were measured, and lab-scale tests were carried out to evaluate the bio-CH4 potential.


Holzforschung ◽  
2009 ◽  
Vol 63 (6) ◽  
Author(s):  
Kim Granholm ◽  
Pingping Su ◽  
Leo Harju ◽  
Ari Ivaska

Abstract Chelation of thermomechanical pulp (TMP) was studied in this work. The desorption of Mn, Fe, and Mg due to their impact on peroxide bleaching was investigated. The desorption experiments were performed with EDTA, citric acid, oxalic acid, and formic acid as chelating agents at different pH. Chelation experiments with EDTA were carried out at pH 3–11. Sodium dithionite was used as the reducing agent in studying chelation with EDTA in a reducing environment. Mn was very effectively desorbed with EDTA from TMP at pH <10 and the reducing environment further improved the removal of all the studied metal ions from TMP with EDTA. Citric acid also removed Mn effectively from TMP at pH 5. The thermodynamic stability constants of different metal chelates do not present the correct picture of how strongly the metal ions are bound by the chelating agents in different conditions. But by means of the side reaction coefficients (α M(L)-coefficients) it is also theoretically possible to evaluate and compare the real binding strengths between the metal ions and different chelating agents at varying pH values and other solution conditions. In this study, a theory is given for the calculation of side reaction coefficients. Values of the α M(L)-coefficients, for the pH range 0–14, are presented for EDTA, DTPA, and also for some other new potential environmentally friendly chelating agents.


1998 ◽  
Vol 38 (1) ◽  
pp. 275-283 ◽  
Author(s):  
P. Battistoni ◽  
P. Pavan ◽  
F. Cecchi ◽  
J. Mata-Alvarez

Phosphate removal in anaerobic supernatant coming from a centrifugation sludge station of an A2O process is studied. A fluidized bed reactor is employed to crystallize phosphate as hydroxyapatite or struvite using only air stripping to reach the supersaturation pH. The classic composition of supernatant (alkalinity 3550 mgCaCO3/l, PO4 139 mg/l, Mg 24 mg/l) does not require any addition of chemicals for phosphate removal. Seventeen runs are performed in a bench scale FBR obtaining very high conversion and removal efficiency and phosphate loss in the effluent ≤3.5%. The use of Ca or Mg enriched supernatant has no meaningful influence on efficiency, but it determines the prevalent salt formed between MAP or HAP. Efficiency can be related to pH and sand contact time in a double saturational model. The half efficiency constants: 0.075 h for t and 7.75 pH, have an important role in the process knowledge and optimization of plant design. Exhaust sand analysis indicates the same composition at the top, bottom and mean of the sand bed (39% mol MAP and 61% mol HAP). This result together with the high half efficiency constant for contact time indicate that the phosphate growth on the bed is not competitive. Finally, the phosphate release from the plant is studied. Results show a weak release rate, equivalent to 2.8-10% d−1 phosphate as MAP, obtained at an operative pH range of 8.1-8.4.


2018 ◽  
Vol 7 (3) ◽  
pp. 123-129 ◽  
Author(s):  
Fakher Ayed ◽  
Hayfa Jabnoun-Khiareddine ◽  
Rania Aydi-Ben-Abdallah ◽  
Mejda Daami-Remadi

Sclerotium rolfsii is one of the devastating soilborne fungus responsible for significant plant losses. The effects of pH and aeration on pathogen mycelial growth, sclerotial production and germination were investigated for three Tunisian isolates. Optimal mycelial growth occurred at pH 6 for Sr2 and Sr3 isolates and at pH 6-7 for Sr1. Dry mycelial growth was optimum at pH values ranging between 4 and 7. Sclerotial initiation started on the 3rd day of incubation at all pH values tested and mature sclerotia were formed after 6 to 12 days. Optimal sclerotial production was noted at pH 5. The dry weight of 100 sclerotia varied depending on isolates and pH and occurred at pH range 4-7. At pH 9, mycelial growth, sclerotial production and dry weight of 100 sclerotia were restricted. The optimum sclerotial germination, noted after 24 h of incubation, varied depending on isolates and pH and occurred at pH 4-9. Mycelial growth was optimum in aerated plates with a significant isolates x aeration treatments interaction. Sclerotial initiation occurred at the 3rd day of incubation and mature sclerotia were observed after 6-9 days. Sclerotial development was very slow in completely sealed plates and dark sclerotia were produced only after 15 days of incubation. The highest sclerotial yields were noted in aerated plates. The highest dry weight of 100 sclerotia for Sr1 isolate was recorded in ½ sealed, no sealed and completely sealed plates, while for Sr2, it was noted in ½ and ⅔ sealed plates. For Sr3, the maximum dry weight of 100 sclerotia was recorded in ½, ⅔ and completely sealed plates. Germination of S. rolfsii sclerotia, after 24 h of incubation, did not vary significantly depending on aeration treatments and ranged from 90 to 100% for all isolates.


2020 ◽  
Vol 83 (1) ◽  
pp. 27-36
Author(s):  
Mardawani Mohamad ◽  
Rizki Wannahari ◽  
Rosmawani Mohammad ◽  
Noor Fazliani Shoparwe ◽  
Kwan Wei Lun ◽  
...  

Used coffee grounds usually end up as landfill. However, the unique structural properties of its porous surface make coffee grounds can be transformed into biochar and performed as an alternative low cost adsorbent. Malachite green (MG) is a readily water soluble dye which is used extensively in textile and aquaculture industries. The mordant complex structures of MG generate destructive effects to animals and environment. In this study, adsorption of malachite green using spent coffee ground biochar as adsorbent was investigated. The experiments were designed in two methods: classical and optimisation by response surface methodology. Three parameters were studied, which are adsorbent dosage, contact time and pH while the responses in this study are malachite green removal (%) and adsorption capacity (mg/g). Optimisation studies were performed using response surface methodology. Quadratic model was chosen for both response and studied using central composite design. The correlation coefficient, R2 for the quadratic model of malachite green removal (%) and adsorption capacity (mg/g) were 0.95 and 0.99, respectively. The optimum malachite green removal (%) predicted was found at 99.27%, by using 0.12 g of adsorbent dosage, 43.05 minutes of contact time and pH of 9.45 at desirability of 1.0. The optimum adsorption capacity (mg/g) predicted was found at 118.01 mg/g, by using 0.02 g of adsorbent dosage, 60 minutes of contact time and pH of 10.24 at desirability of 0.98. So, it was concluded that the spent coffee ground biochar can be used as an effective adsorbent for malachite green removal from aqueous solution.


2013 ◽  
Vol 62 (1) ◽  
pp. 101-108 ◽  
Author(s):  
LUBNA TAHIR ◽  
MUHAMMAD ISHTIAQ ALI ◽  
MUHAMMAD ZIA ◽  
NAIMA ATIQ ◽  
FARIHA HASAN ◽  
...  

Polystyrene is considered stable to biological degradation. Lantinus tigrinus isolated from wood sample produced esterase in growth medium under normal conditions. However, acidic medium, 37 degrees C temperature, presence of tween 80; and urea and yeast extract in mineral salt medium enhance the production of esterase and specific activity. Purified esterase was active at broad pH range and 45 degrees C. FTIR analysis confirmed that esterase produced by Lantinus tigrinus effectively degraded polystyrene film and broke macromolecules down to non-toxic molecules. This study concludes that the presence of Lantinus tigrinus at dumping sites can be exploited for waste management containing high molecular weight synthetic polymers.


Author(s):  
Daniela CIUPEANU CĂLUGĂRU

For turning to a high degree of favorability of sludge from wastewater treatment plants, currently the reintroduction in the natural circuit of this waste is an urgent priority. Knowing precisely the composition of chemical and biological sludge from waste water in accordance with the law and the rules of their application, along with modern wastewater treatment appropriate technologies play a key role on environmental protection. Involvement by precise rules, the content of heavy metals in relation to the maximum permitted by law, translate in to particularly advantageous results in terms of environmental quality.


1983 ◽  
Vol 40 (11) ◽  
pp. 1905-1911 ◽  
Author(s):  
R. W. Nero ◽  
D. W. Schindler

The population size of Mysis relicta in Lake 223 of the Experimental Lakes Area, northwestern Ontario, decreased from 6 700 000 ± 1 330 000 (± 95% confidence limits) during August of 1978, to 270 000 ± 75 000 during August of 1979, a 96% decrease. Because Mysis, a cold stenotherm, is restricted to the metalimnion and hypolimnion of lakes during summer, the pH range encountered by the population was 5.51 to 6.32 in 1978 and 5.23 to 6.10 in 1979, even though mean pH values in epilimnion waters for the 2 yr were 5.84 and 5.60. A decrease in pH of its habitat from 6.2 to 5.6 during fall overturn in 1979 caused the elimination of the remaining 4% of the population. Comparisons with four control lakes suggested that the decline and disappearance were not normal occurrences in unstressed lakes. Concentrations of Zn, Al, Mn, Fe, Cd, Cu, Ni, and Hg in Lake 223 water were low, and concentrations in Mysis were less than or equal to those in animals from five control lakes, suggesting that the decline in this species was not due to the toxic effects of metals. All size classes were affected, so that direct toxicity of hydrogen ion may be responsible for this abrupt population collapse. These results suggest that Mysis may be a useful early indicator of acidification damage to Precambrian Shield lakes.


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