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2021 ◽  
Vol 2120 (1) ◽  
pp. 012037
Author(s):  
S Nalatambi ◽  
K S Oh ◽  
L W Yoon

Abstract A novel chitosan/alginate composite membrane is proposed for the application of greywater treatment. In particular, the effect of stirring speed of mixing chitosan and alginate solution was investigated in this study. The study revealed that 150CSAL and 210CSAL membranes swell significantly compared to CS membrane due to the porous structure of composite membrane. The FTIR spectra revealed that the mixing speed has no influence in terms of molecular interaction between CS and AL due to fixed CS and AL concentrations used in this study. On the other hand, the complexation of AL with CS made outstanding improvement to the dense structure of CS where 180CSAL membrane has UP water flux as high as 90 L/m2h at 2 bar. All membranes have the capability to remove the pollutants present in GW and the COD removal was further improved up to 7% using CSAL membranes. In addition, increasing mixing speed improved the pathogen removal efficiency compared to CS membrane. The treated GW met the non-potable GW reuse standard for turbidity<5 NTU and TSS<20 mg/L. To summarize, the proposed fabrication technique on CSAL membrane showed improved characteristics to CS membrane and has significant performance on GW treatment.


Author(s):  
Irshad. S. Shaikh

Textile industry is one of the major industries in the world that provide employment with no required special skills and play a major role in the economy of many countries. The textile industry utilizes various chemicals and large amount of water during the production process. Colour is the major pollutants present in the effluent from various textile industries. These are highly toxic to living things and have hazardous effect on their health. Thus removal of colour using natural flocculant is a major step towards the protection of natural resources. Coagulation-flocculation is the most widely used method and is applicable for the removal of the colour even at low concentrations. This paper represents the results of investigations carried out for the removal of colour along with SS, DS, TS and COD from waste water by using natural flocculant i.e. Cactus, Aloevera, and combination of Cactus & Aloevera. The colour removal efficiency of flocculant was investigated by batch wise coagulation flocculation method. The effect of various important parameters on the % removal of colour was studied to find the optimum condition for the maximum removal of colour. The parameters like pH, coagulant dose, flocculant dose, coagulant mixing time, coagulant mixing speed, flocculant mixing time, flocculant mixing speed, setting time & concentration of waste water were investigated. These parameters for Cactus were found to be 12, 10 ml/L, 20 ml/L, 2 min, 140 rpm, 15 min, 70 rpm, 6 min, 300 ml/L respectively, for Aloevera were Journal of Water Resource Engineering & Pollution Studies Volume 5 Issue 1 found to be 11.5, 10 ml/L, 100 ml/L, 2 min, 140 rpm, 15 min, 30 rpm, 1 min, 300 ml/L respectively and simultaneously for combination of Cactus & Aloevera were found to be 12, 10 ml/L, 10% + 80% (Cactus + Aloevera dose) ml/L, 2 min, 140 rpm, 25 min, 50 rpm, 10 min, 300 ml/L respectively. These natural flocculants gives maximum colour removal efficiency in the range 85-100%. The colour removal efficiency was found in between 85-100% for all parameters. All the result was validated on the basis of mathematical analysis. All the graphs were fitted to various trend lines out of which polynomial third order curve is best fit to experimental work as the coefficient of correlation (R2 value) is closer to unity.


2021 ◽  
Vol 1203 (2) ◽  
pp. 022003
Author(s):  
Grzegorz Mazurek ◽  
Marcin Podsiadło

Abstract At the present time, the utilization of waste polymer materials belongs to one of the most important challenges where global economies have to tackle. This article concerned the modification of petroleum road bitumen with waste polymer. The bitumen modification process with the use of polymeric materials was carried out considering a number of other quantitative factors, such as: mixing time, mixing speed, bitumen temperature and qualitative factors such as: waste polymer content, type of grain size, type of neat bitumen and type of waste polymer. Two kinds of waste polymers (PET, PP) were used in the research, which served as a modifier. Two petroleum bitumens were used: 20/30 (hard) and 70/100 (soft). Based on the divalent Plackett-Burman experiment plan, the number of variables and the number of combinations of mixtures were determined, which were required to determine the final response surface model. The following features were tested as the output variables: penetration, softening point, Fraass breaking point, dynamic viscosity 60oC, 90oC, 135oC, deformation energy and maximum elongation. The use of the experimental design methodology allowed to identify the factors that had the greatest impact on the bitumen modification process. The assessment of the significance of the parameters also allowed to identify a significant model allowing to find the optimal bitumen and waste polymer composition. Based on the test results, it was shown that the consistency of the modified bitumen was influenced by the type of bitumen, its amount, mixing speed and mixing time. With regard to the softening point, the type of polymer was also an important factor. Ultimately, the optimization process allowed for the determination of such a combination of both qualitative and quantitative input factors, which resulted in bitumen showing higher utility than input 20/30 and 70/100 bitumens. Moreover, it was found that the increase in mixing time did not result in an excessive increase in bitumen stiffness caused by the mixing process. Thus, the low-temperature properties left unchanged significantly


2021 ◽  
Vol MA2021-02 (37) ◽  
pp. 1085-1085
Author(s):  
Erin Creel ◽  
Carlos Baez-Cotto ◽  
James L. Young ◽  
Scott A Mauger ◽  
Michael Ulsh ◽  
...  

2021 ◽  
Vol 25 (Special) ◽  
pp. 3-123-3-129
Author(s):  
Nada S. Joodi ◽  
◽  
Nagam O. Kariem ◽  

The AOPs advanced oxidation process has been studied in three ways: (UV/H₂O₂), Fenton, and Photo-Fenton in artificial water treating from vegetable oils. The corn, castor, and coconut oils emulsion were prepared and treated by AOPs. Several variables were studied: time, pH, mixing speed, temperature, the dose of chemicals (H₂O₂ & Fe2SO4.7H2O), and finally the oil concentration. The best conditions were obtained in several experiments where the Fenton and Photo-Fenton process operates in an acidic medium (pH = 3.5), while the UV/H₂O₂ process operates with the neutral medium (pH = 7). The optimum temperature for the Photo-Fenton and UV/H₂O₂ processes is 40°C, and for the Fenton process is 20°C. While there was an effect of mixing speed, higher efficiency was achieved at (1000 rpm) for the Photo-Fenton process and (500 rpm) for the Fenton and UV/H₂O₂ processes. Also, the H₂O₂ concentration was at (500 mg/L) for all processes, when the Fe2SO4.7H2O concentration for the photo-Fenton process = (50 mg/L), and for the Fenton process = (250 mg/L). Oil concentration = (1750 mg/L). Optimum conditions were applied to treat vegetable oils, the Fenton process gave a maximum removal efficiency of 95.2% for corn oil (COD 12800 to 610 mg/L), 94.5% for castor oil, while 57.5% for coconut oil after the total reaction time (180 minutes). The Photo-Fenton process gave removal efficiencies: 93% for corn oil (COD 12500 to 870 mg/L), 83.8% for castor oil, and 61.6% for coconut oil. The UV/H₂O₂ process gave removal efficiencies: 69.8% for corn oil, 32% for castor oil, and 23.4% for coconut oil after the total irradiation time. As real wastewater, the treatment was acceptable and achieved an efficiency of 44.7%, 89.2%, and 83.8% for the UV/H₂O₂, Fenton, and Photo-Fenton processes, respectively.


Author(s):  
Samuel Owusu Nti ◽  
Richard Buamah ◽  
Janet Atebiya

Abstract Alum, the predominant coagulant in conventional drinking water treatment schemes, has various disadvantages including the production of large volumes of sludge, lowering water pH (requiring pH adjustment using lime), limited coagulation pH range of 6.5 to 8.0, etc. At the Barekese Water Treatment Plant in Ghana, an alternative, the polyelectrolyte – Polyaluminium chloride (PAC) is also used in coagulation but limited information is available on the operating conditions required to achieve better performance than alum-based coagulation. The aim of this study was to determine the optimal coagulant dose, mixing speed and operating pH for enhanced performance in water treatment. The effects on the treatment process of three different sets of mixing speed pairs – 180/40, 180/25 and 150/25 revolutions per minute (fast/slow) – in a pH range of 6.5 to 8.0 were investigated. The mixing speed and PAC dose yielding the best coagulation were 150/25 rpm and 15 mg/L respectively. The optimal pH range for PAC coagulation performance was 7.5 to 8.0.


2021 ◽  
Vol 9 (7) ◽  
pp. 1443
Author(s):  
Heidi L. Cossey ◽  
Mian Nabeel Anwar ◽  
Petr V. Kuznetsov ◽  
Ania C. Ulrich

End pit lakes (EPLs) have been proposed as a method of reclaiming oil sands fluid fine tailings (FFT), which consist primarily of process-affected water and clay- and silt-sized particles. Base Mine Lake (BML) is the first full-scale demonstration EPL and contains thick deposits of FFT capped with water. Because of the fine-grained nature of FFT, turbidity generation and mitigation in BML are issues that may be detrimental to the development of an aquatic ecosystem in the water cap. Laboratory mixing experiments were conducted to investigate the effect of mudline biofilms made up of microbial communities indigenous to FFT on mitigating turbidity in EPLs. Four mixing speeds were tested (80, 120, 160, and 200 rpm), all of which are above the threshold velocity required to initiate erosion of FFT in BML. These mixing speeds were selected to evaluate (i) the effectiveness of biofilms in mitigating turbidity and (ii) the mixing speed required to ‘break’ the biofilms. The impact of biofilm age (10 weeks versus 20 weeks old) on turbidity mitigation was also evaluated. Diverse microbial communities in the biofilms included photoautotrophs, namely cyanobacteria and Chlorophyta (green algae), as well as a number of heterotrophs such as Gammaproteobacteria, Desulfobulbia, and Anaerolineae. Biofilms reduced surface water turbidity by up to 99%, depending on the biofilm age and mixing speed. Lifting and layering in the older biofilms resulted in weaker attachment to the FFT; as such, younger biofilms performed better than older biofilms. However, older biofilms still reduced turbidity by 69% to 95%, depending on the mixing speed. These results indicate that biostabilization is a promising mechanism for turbidity mitigation in EPLs.


2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Marcus Vinicius Ribeiro Ruggeri ◽  
Rodrigo Felipe Bedim Godoy ◽  
Pedro Augusto Arroyo ◽  
Elias Trevisan

AbstractThis study assesses two parameters that can result in high efficiency in the recovery of the microalgae Monoraphidium contortum. The significant contribution of this paper is to test different coagulants in different conditions of concentration in the coagulation and flocculation processes followed by sedimentation to evidence the best coagulant and the best condition for harvesting of Monoraphidium contortum biomass. So the proposed methodology aimed to perform preliminary tests using a tannin-based cationic coagulant (TANFLOC SG®), FeCl2, and Al2 (SO4)3, where they were performed at concentrations of 0, 20, 40, 60, 80, and 100 mg L−1 at a fast mixing speed of 400 RPM. The tests determined 20 mg L−1 of Tanfloc SG® as the most efficient turbidity reduction in the preliminary test. The obtained results were used to construct a non-factorial central composite planning. Therefore, after a design of experiments, the study outcome shows the best turbidity removal range from the main tests came at 35 mg L−1 and 550 RPM of fast mixing speed.


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