scholarly journals Possible applications of ferrate(VI) in the treatment of industrial wastewater effluent in the laboratory

2015 ◽  
Vol 69 (1) ◽  
pp. 43-50
Author(s):  
Ljiljana Nikolic-Bujanovic ◽  
Milan Cekerevac ◽  
Milena Tomic ◽  
Mladen Zdravkovic

This paper shows the effects of ferrate(VI) application in the treatment of industrial wastewater effluent in laboratory conditions. Samples used are a mixture of wastewater effluent from various industrial plants whose composition was determined by analyzing samples before the ferrate(VI) treatment. Determining physical-chemical characteristics of the samples showed very high chemical oxygen demand (COD) and the concentrations of individual pollutants are higher than the maximum allowed. In the tested samples, the COD was from 18 (sample 1) to 580 times (sample 2) greater than allowed (allowed 45 - 150 mg/l), while the concentrations of certain metals were several times higher than allowed (Cu allowed 0,1 mg/l, Zn allowed 0,2 mg/l). Also, a high concentration of total phosphorus content (allowed 2 mg/l) and fluoride was found (allowed 20 mg/l), 2-3 times higher than permissible. The applied Na2FeO4 was synthesized by electrochemical method and applied in situ. Physical-chemical testing of samples, after treatment with different amounts (2, 5, 8, and 10 ml) of Na2FeO4, concentration of 8 g/l showed that ferrate(VI) can be used as a multifunctional agent in the purification of industrial wastewater, where in the amount of contaminating matter is reduced below the maximum permitted level. It was demonstrated the high efficiency of ferrate(VI) as a strong oxidant in the removal of total P and suspended materials. Also pointed out was the high sorption power of the generated ferric(III)hydroxide, which with its developed surface absorbs 95,5% of the F- and removes it from the solution in the form of sludge. Showed a high efficiency of ferrate(VI) in the total removal of P (70 to 99,5%), and F- (89 to 95,5%), but depending on the presence of the total COD value or the presence of the total organic substances. At high values of the COD major part of ferrate(VI) is consumed in the oxidation of organic material and the formation of Fe(OH)3, which accelerate the process of decomposition of ferrate(VI), which contributes to lower the efficiency of the removal of P and F-.

2013 ◽  
Vol 68 (6) ◽  
pp. 1223-1232 ◽  
Author(s):  
M. Gajewska ◽  
H. Obarska-Pempkowiak

The paper presents the influence of sewage composition on treatment in pilot-scale facility for reject waters (RW) from sewage sludge centrifugation. The facility consisted of mechanical (two tanks with 10 d retention each) and biological parts composed of three subsurface flow reed beds working in batch. Two years of monitoring of the facility proved high efficiency removal of predominant pollutants: chemical oxygen demand (COD) 75–80%, biochemical oxygen demand (BOD) 82.2–95.5% and total nitrogen 78.7–93.9% for low ratio of BOD5/COD in discharged RW. The differences in efficiency removal were correlated with the composition of organics and nitrogen compounds rather than with concentrations. It was assumed that high concentration of colloidal fraction of Org-N and COD in discharged RW led to a decrease in efficiency removal.


2020 ◽  
Author(s):  
◽  
Jeremiah Adedeji

The increasing demand for energy has led to the utilization of fossil fuels more abundantly as a quick alternative for generation of energy. The use of these sources of energy however as led to the generation of greenhouse gases which tend to cause climate change, thus affecting the ecosystem at large. Thus, there have been the search for alternative sources which cannot be depleted but do generate minimal greenhouse gases. One of such alternate sources is industrial wastewater which have shown to have high concentration of nutrients in the form of organic contents which can be converted by micro-organisms into energy, usually known as biogas, comprising majorly of CH4, CO2 and H2. Another important factor is that industrial wastewaters are a renewable energy source which are continuously generated due to increasing urbanisation and population growth. In this study, the characteristics of three agro-industrial based wastewaters used shows their potential for application in anaerobic co-digestion”. Anaerobic co-digestion method was utilized to harness the synergetic effect of both sewage sludge and agro-industrial wastewater as co-substrate for the generation of biomethane. The result of the effect of varying mix-ratio of the substrates on biomethane production of sugar wastewater and dairy wastewater indicated that mix-ratio of 1:1 for sewage sludge to sugar wastewater operated at 35oC was suitable for optimum generation of biomethane of 1400.99 mL CH4/g COD added and COD reduction of 54%. The model generated using design expert was found to navigate the design space and could perfectly predict the yield of biomethane effectively for the sugar wastewater mix. The biomethane potential tests (BMP) experiment using varying inoculum-substrate ratio (ISR) showed that operating at mesophilic temperature of 25oC with ISR of 1:2 and 2:1 for sugar wastewater and dairy wastewater respectively does increase the methane production within the first three (3) weeks. The kinetic models that best fit the anaerobic co-digestion for sugar wastewater was the first order model while the simplified Gompertz model favoured the dairy wastewater perfectly. The biomethane potential tests indicate significant increase the biomethane production and as well reduction in the volatile solid and chemical oxygen demand (COD) content. In conclusion, both sugar and dairy wastewater can be recommended as co-substrates for anaerobic digestion of sewage sludge for increased and improved biomethane production while simultaneously reducing their COD content at the same time.


2011 ◽  
Vol 64 (1) ◽  
pp. 117-121 ◽  
Author(s):  
Y. J. Lei ◽  
X. B. Wang ◽  
C. Song ◽  
F. H. Li ◽  
X. R. Wang

Ruthenium-based catalysts were prepared by a saturation-dip method. Their catalytic activity was evaluated by a catalytic wet oxidation (CWO) process. The ruthenium-based catalysts were used to purify organic pharmaceutical wastewater with high concentration pyridine and pyridine derivatives that have high chemical oxygen demand (COD). In the CWO process, organic pharmaceutical wastewater was continuously pumped into fixed-bed reactors filled with Ru-based catalysts, while the organic components in wastewater were catalytically degraded by oxygen at high temperatures and pressures (temperature, 170–300 °C; pressure, 1.0–10 MPa). The experimental results showed that the prepared catalysts could effectively purify pharmaceutical wastewater with high concentration organic components, which are difficult to degrade biochemically, and that the removal rates of both COD and total nitrogen were over 99%.


Author(s):  
Giti Kashi ◽  
Shahrbanou Younesi ◽  
Alireza Heidary ◽  
Zeinab Akbarishahabi ◽  
Babak Kavianpour ◽  
...  

Abstract Carwash is known as one of the most important urban services bring about production of huge volume of wastewater with high turbidity and high chemical oxygen demand (COD). Seasonal and carwash location features affect the quality of carwash wastewater. Various methods with special focus on chemical processes have been employed for carwash wastewater treatment and eliminating different pollutants from this wastewater of great concern for the environment. This review was conducted for identifying and comparing the efficiency of chemical processes for carwash wastewater treatment. To this aim, key words were identified and a search protocol was defined to search studies in three databases: Scopus, Web of Science, and PubMed. The results of this systematic review indicated that coagulation (66%) is the most common chemical processes for carwash wastewater treatment. Although chemical processes are able to reduce the turbidity and COD over 80%. Due to the characteristics of carwash wastewater, chemical processes are a necessary pre-treatment for processes such as membrane technology. Rapid treatment and high efficiency are the advantages of wastewater treatment by chemical methods, but the energy consumption and sludge volume are two main factors in selection the chemical processes for carwash wastewater treatment.


NANO ◽  
2019 ◽  
Vol 14 (09) ◽  
pp. 1950119 ◽  
Author(s):  
Chuncheng Yang ◽  
Mengchun Yu ◽  
Xiuling Cao ◽  
Xiufang Bian

Amorphous magnetic particles demonstrate excellent comprehensive properties and outstanding characteristics for numerous applications. In this report, magnetic crystalline Fe3O4 and amorphous Fe-B nanoparticles were successfully synthesized and introduced to prepare water-based magnetic fluids. The Fe3O4 and Fe-B particles are homogeneous nanoparticles with an average particle size of [Formula: see text][Formula: see text]nm. The shape of Fe-B amorphous nanoparticles is regular. The saturation magnetizations of Fe-B and Fe3O4 particles are 74 emu/g and 69 emu/g. The use of crystalline Fe3O4 magnetic fluid and amorphous Fe-B magnetic fluid in advanced treatment of high concentration organic wastewater was presented. The removal rate of chemical oxygen demand by using the amorphous Fe-B magnetic fluid reached 96%, about 16% higher than that by using the Fe3O4 magnetic fluid. Moreover, compared with Fe3O4 magnetic fluid, the treatment results demonstrate that the decolorizing effect by using the amorphous Fe-B magnetic fluid was 20% higher. It has been found that the nano-size Fe-B particles in magnetic fluid with amorphous structure led to high efficiency of wastewater treatment due to the catalytic activity.


2014 ◽  
Vol 07 (03) ◽  
pp. 1450028 ◽  
Author(s):  
Chun-Cheng Yang ◽  
Xiu-Fang Bian ◽  
Jian-Fei Yang

Using combination of ferrofluid (FF) and Fe -based amorphous alloy in the advanced treatment of high concentration, organic wastewater was investigated. The addition of Fe 73.5 Nb 3 Cu 1 Si 13.5 B 9 amorphous alloy powders into a FF give rise to a dramatic enhancement in decreasing chemical oxygen demand (COD) and decolorization. The removal rate of COD by using FF that combined Fe 73.5 Nb 3 Cu 1 Si 13.5 B 9 metallic glass (MG) particles reached 92% in the presence of H 2 O 2, nearly more than 50% higher than that by using only FF. Furthermore, compared with the FF, the decolorizing effect of the combination was 20% higher. It has been found that MG powders with the amorphous structures have high efficiency of waste water treatment and lead to high catalytic ability.


2014 ◽  
Vol 13 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Ghasem Najafpour Darzi ◽  
Reza Katal ◽  
Hossein Zare ◽  
Seyed Omid Rastegar ◽  
Poorya Mavaddat

1999 ◽  
Vol 40 (3) ◽  
pp. 57-65 ◽  
Author(s):  
Martin M. Karpiscak ◽  
Robert J. Freitas ◽  
Charles P. Gerba ◽  
Luis R. Sanchez ◽  
Eylon Shamir

An integrated wastewater treatment facility, consisting of upper (solids separators, anaerobic lagoons, and aerobic ponds) and lower (wetland cells) subsystems, has been built to replace the lagoon at a dairy in Arizona, USA. The collection sump of the new waste treatment facility collects all dairy wastewater outflow. Wastewater is then pumped to solids separators, and flows by gravity to anaerobic ponds and aerobic ponds. The upper subsystem is expected to treat the water sufficiently so that the wetland cells may achieve further pollutant reductions. The lower subsystem, comprised of 8 surface wetland cells with an approximate surface area of 5,000 m2, receives outflow from the ponds. The cells are planted with cattail (Typha domingensis), soft-stem bulrush (Scirpus validus), and reed (Phragmites australis). After treatment is completed via the lagoons and ponds followed by the wetland cells, the wastewater can be reused to flush barns or to irrigate crops. Performance of the overall system is evaluated by measuring physical, chemical and biological parameters in water samples taken from selected locations along the treatment system. Chemical parameters studied include biochemical oxygen demand, pH, total suspended solids, nitrogen species. Biological monitoring included coliforms (total and fecal) and Listeria monocytogenes.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yingfeng Yang ◽  
Hanze Ying ◽  
Zhixia Li ◽  
Jiang Wang ◽  
Yingying Chen ◽  
...  

AbstractMacrocycles are unique molecular structures extensively used in the design of catalysts, therapeutics and supramolecular assemblies. Among all reactions reported to date, systems that can produce macrocycles in high yield under high reaction concentrations are rare. Here we report the use of dynamic hindered urea bond (HUB) for the construction of urea macrocycles with very high efficiency. Mixing of equal molar diisocyanate and hindered diamine leads to formation of macrocycles with discrete structures in nearly quantitative yields under high concentration of reactants. The bulky N-tert-butyl plays key roles to facilitate the formation of macrocycles, providing not only the kinetic control due to the formation of the cyclization-promoting cis C = O/tert-butyl conformation, but also possibly the thermodynamic stabilization of macrocycles with weak association interactions. The bulky N-tert-butyl can be readily removed by acid to eliminate the dynamicity of HUB and stabilize the macrocycle structures.


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