scholarly journals Solar photo-Fenton with simultaneous addition of ozone for the treatment of real industrial wastewaters

2018 ◽  
Vol 77 (10) ◽  
pp. 2497-2508 ◽  
Author(s):  
S. Sanchis ◽  
L. Meschede-Anglada ◽  
A. Serra ◽  
F. X. Simon ◽  
G. Sixto ◽  
...  

Abstract Simultaneous application of solar photo-Fenton and ozonation (SPFO) for the efficient treatment of real wastewaters was studied. Four different industrial effluents were selected for the study: landfill leachate, pharmaceutical effluent and two textile wastewaters, in order to demonstrate the effectiveness and versatility of the proposed technology. SPFO performance was compared with individual processes (either solar photo-Fenton or ozonation), as well as the hybrid Fenton and ozonation treatment. In highly polluted wastewaters, combined strategies led to higher organic matter removal than O3 and photo-Fenton processes applied individually. Solar light favoured catalyst regeneration, allowing removal efficiencies up to 67% of chemical oxygen demand (COD) and 62% of total organic carbon (TOC) (in the case of textile wastewaters) using an initial concentration of only 10 mg Fe2+ L−1. The reduction of catalyst consumption, along with the absence of sludge production (since Fe2+ removal from the effluent is not required), led to a significant decrease in operational costs (up to 1.22 € kg−1 COD removed) when combined Fenton and ozonation was applied under solar light. SPFO results in a versatile, effective and economically efficient technology, thus postulating as a promising alternative for reducing the organic load of highly polluted industrial effluents prior to biological treatment.

2020 ◽  
Vol 81 (9) ◽  
pp. 1914-1926 ◽  
Author(s):  
Y. Jaouad ◽  
M. Villain-Gambier ◽  
L. Mandi ◽  
B. Marrot ◽  
N. Ouazzani

Abstract Membrane bioreactor (MBR) has been proven to be an efficient technology capable of treating various industrial effluents. However, the evaluation of its performances in the case of olive mill wastewater (OMW) over a conventional activated sludge (CAS) have not been determined yet. The present study aims to compare OMW treatment in two laboratory scale pilots: an external ceramic MBR and CAS starting with an acclimation step in both reactors by raising OMW concentration progressively. After the acclimation step, the reactors received OMW at 2 gCOD/L with respect to an organic loading rate of 0.2 and 0.3 kgCOD/kgMLVSS/d for MBR and CAS, respectively. Biomass acclimation occurred successfully in both systems; however, the MBR tolerated more OMW toxicity than CAS as the MBR always maintained an effluent with a better quality. At a stable state, a higher reduction of 95% chemical oxygen demand (COD) was obtained with MBR compared to CAS (86%), but both succeeded in polyphenols removal (80%). Moreover, a higher MLSS elimination from the MBR treated water (97%) was measured against 88% for CAS. Therefore, CAS was suitable for OMW treatment and MBR could be proposed as an alternative to CAS when a better quality of treated water is required.


2020 ◽  
Vol 8 (10) ◽  
pp. 1588
Author(s):  
Graziella Chuppa-Tostain ◽  
Melissa Tan ◽  
Laetitia Adelard ◽  
Alain Shum-Cheong-Sing ◽  
Jean-Marie François ◽  
...  

Sugarcane Distillery Spent Wash (DSW) is among the most pollutant industrial effluents, generally characterized by high Chemical Oxygen Demand (COD), high mineral matters and acidic pH, causing strong environmental impacts. Bioremediation is considered to be a good and cheap alternative to DSW treatment. In this study, 37 strains of yeasts and filamentous fungi were performed to assess their potential to significantly reduce four parameters characterizing the organic load of vinasses (COD, pH, minerals and OD475nm). In all cases, a pH increase (until a final pH higher than 8.5, being an increase superior to 3.5 units, as compared to initial pH) and a COD and minerals removal could be observed, respectively (until 76.53% using Aspergillus terreus var. africanus and 77.57% using Aspergillus niger). Depending on the microorganism, the OD475nm could decrease (generally when filamentous fungi were used) or increase (generally when yeasts were used). Among the strains tested, the species from Aspergillus and Trametes genus offered the best results in the depollution of DSW. Concomitant with the pollutant load removal, fungal biomass, with yields exceeding 20 g·L−1, was produced.


2016 ◽  
Vol 75 (1) ◽  
pp. 228-238 ◽  
Author(s):  
Antoine Prandota Trzcinski ◽  
Chong Wang ◽  
Dongqing Zhang ◽  
Wui Seng Ang ◽  
Li Leonard Lin ◽  
...  

A biosorption column and a settling tank were operated for 6 months with combined municipal and industrial wastewaters (1 m3/hr) to study the effect of dissolved oxygen (DO) levels and Fe3+ dosage on removal efficiency of dissolved and suspended organics prior to biological treatment. High DO (>0.4 mg/L) were found to be detrimental for soluble chemical oxygen demand (COD) removals and iron dosing (up to 20 ppm) did not improve the overall performance. The system performed significantly better at high loading rate (>20 kg COD.m−3.d−1) where suspended solids and COD removals were greater than 80% and 60%, respectively. This is a significant improvement compared to the conventional primary sedimentation tank, and the process is a promising alternative for the pre-treatment of industrial wastewater.


2018 ◽  
Vol 10 (1) ◽  
pp. 367-374 ◽  
Author(s):  
Sangeeta Madan ◽  
Preeti Sachan ◽  
Utkarsh Singh

At present, a large amount of water required for paper production and various chemicals has been identified in effluents, which is produced at different steps of paper making in paper mills. The pulp and paper industry is typically related to pollution difficulties related to high biological oxygen demand (BOD), chemical oxygen demand (COD), colour, suspended solids, lignin and chlorinated compounds. Several studies have been made on eliminate these difficulties of pulp and paper effluents, the problem still continues. Although the physical and chemical methods are on the track of treatment, they are not on par with biological treatment because of cost ineffectiveness and residual effects. The biological treatment is known to be effective in reducing the organic load and toxic effects of paper mill effluents. Some microorganisms including bacteria and fungi have been involved in degrading the chemicals present in pulp and paper mill effluent. This article is an overview of the attempts made by several researchers worldwide to use biotechnological methods for degradation of the toxic compounds present in pulp and paper mill effluents by using fungi, bacteria, algae and enzymes. The current study clearly shows that application of native dominant bacterial and fungal isolates may be used forthe treatment of large pulp and paper mills effluents.


2015 ◽  
Vol 71 (8) ◽  
pp. 1165-1172 ◽  
Author(s):  
Xiangjuan Ma ◽  
Yang Gao ◽  
Hanping Huang

Attempts were made in this study to examine the efficiency of electrocoagulation (EC) using aluminum (Al) anode and stainless steel net cathode combined with electrochemical oxidation with a β-PbO2 anode or a mixed metal oxide (MMO) anode for treatment of papermaking tobacco sheet wastewater, which has the characteristics of high content of suspended solids (SS), intensive color, and low biodegradability. The wastewater was first subjected to the EC process under 40 mA/cm2 of current density, 2.5 g/L of NaCl, and maintaining the original pH of wastewater. After 6 minutes of EC process, the effluent was further treated by electrochemical oxidation. The results revealed that the removal of SS during the EC process was very beneficial to mass transfer of organics during electrochemical oxidation. After the combined process, 83.9% and 82.8% of chemical oxygen demand (COD) removal could be achieved on the β-PbO2 and MMO anodes, respectively. The main components of the final effluent were biodegradable organic acids, such as acetic acid, propionic acid, butyric acid, valeric acid, and hexahyl carbonic acid; the 5-day biochemical oxygen demand/chemical oxygen demand (BOD5/COD) ratio increased from 0.06 to 0.85 (Al + β-PbO2) or 0.80 (Al + MMO). Therefore, this integrated process is a promising alternative for pretreatment of papermaking tobacco sheet wastewater prior to biological treatment.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Andrea Speltini ◽  
Federica Maraschi ◽  
Michela Sturini ◽  
Valentina Caratto ◽  
Maurizio Ferretti ◽  
...  

The aim of this work was to couple physical-chemical approaches with photocatalysis to reduce by a simple, inexpensive way the organic load of olive mill wastewater (OMW), mandatorily prior to the final discharge. Before irradiation, different sorbents were tested to remove part of the organic fraction, monitored by measuring chemical oxygen demand (COD) and polyphenols (PP). Different low-cost, safe materials were tested, that is, Y zeolite (ZY), montmorillonite, and sepiolite. Considerable decrease of organic load was obtained, with the highest abatement (40%) provided by ZY (10 g L−1in 1 : 10 OMW). Use of the three sorbents, in particular ZY, was convenient compared to commercial activated carbons. UV light photocatalytic tests, performed using P25 TiO2on ZY-treated OMW, yielded quantitative remediation (ca. 90%). Also solar light provided significative results, PP being lowered by 74% and COD by 56%. Sol-gel anatase TiO2and N-doped anatase TiO2were also tested, obtaining good results, around-80% PP and-40% COD. Finally, an integrated approach was experimented by ZY-supported anatase TiO2(TiO2@ZY). Thisphotoreactive sorbentallowedone-pottreatment of OMW significative abatements of PP (-77%) and COD (-39%) with only 1 g L−1material, under solar light.


2018 ◽  
Vol 15 (29) ◽  
pp. 276-281
Author(s):  
M. L. NIELAND ◽  
M. C. DALLAZEN ◽  
A. UEBEL ◽  
M. P. MÜLLER ◽  
M. COLLING ◽  
...  

The dairy industry plays a major role both economically and socially in Brazil. However, it generates a significant volume of effluent that presents high organic load. Because of this, a proper treatment is required for the generated effluent, trying to minimize the environmental impacts of its disposal. One of the alternatives to make these wastes in accordance to the environmental standards is the use of flocculants and coagulants that are capable of neutralizing the negative charges, causing the particles to come together to facilitate the separation process. This study aims to analyze the efficiency of flocculants for the treatment of effluent from a dairy company located in the central region of the state of Rio Grande do Sul, in the Taquari Valley. The flocculants used were Aquafloc and Aquaflot. For this, the parameters of Oils and Greases, Sedimentable Solids and Chemical Oxygen Demand (COD) were tested. Similar results were obtanied with both flocculants. However, from the analyzed parameters, Aquafloc proved to be more efficient for removal of COD.


2021 ◽  
Author(s):  
Vivek Rana

Abstract River Kali-East, a tributary of river Ganga, is a non-perennial river of India which is highly driven by the discharge of sewage and industrial effluent. Twenty-seven locations on the entire stretch (approx. 550 km) of river Kali-East were monitored which indicated that color varied as 20-200 Hazen, dissolved oxygen (DO) as 0-8.16 mg/l, biochemical oxygen demand (BOD) as 6.6-410 mg/l, chemical oxygen demand (COD) as 22-1409 mg/l, total suspended solids as 38-4386 mg/l, total dissolved solids as 180-2536 mg/l and fecal coliform as 4.9 × 102 - 34 × 107 MPN/100 ml. High BOD and COD in the river revealed untreated/partially treated industrial discharge into the river and the self-purification capacity of the river Kali-East has been inhibited for a long distance by heavy and undiminished influx of domestic sewage into the river. Twenty-six drains discharge a total organic load of 148 tonnes per day into the river. Maximum pollution load was contributed by Odean Nala (42%) in Meerut district. This study recommends strict regulatory norms for discharge of industrial effluents by the industries in the catchment area of the river, reduction in sewage treatment gap by utilizing alternative treatment technologies (such as constructed wetlands) and proper dilution of polluted river water to improve the overall quality of the river.


Author(s):  
N. Zaletova ◽  
S. Zaletov

Биологический метод очистки сточных вод представляет собой сложный многокомпонентный процесс, ключевой составляющей которого является работа ферментной системы. Известно, что одним из важнейших ферментов, обеспечивающих биологический процесс, являются дегидрогеназы. Полностью сложнейший механизм действия ферментов до конца пока не раскрыт, однако в практике контроля процессов биологической очистки используется показатель дегидрогеназной активности ила. Результаты исследований позволили дополнить имеющуюся информацию фактическими данными о взаимообусловленности уровня дегидрогеназной активности ила и показателей отдельных технологических параметров биологической очистки. Показано, что режим работы аэротенков (нагрузка на ил, доза активного ила и др.) и величина показателей исходной дегидрогеназной активности и дегидрогеназной активности этого же образца ила со слабо концентрированным раствором (ДАИН2О) связаны между собой и зависят от нагрузки на ил по органическим веществам. Полученные результаты исследования могут быть использованы для контроля биологического процесса очистки сточных вод.The biological method of wastewater treatment is a comprehensive multicomponent process the activities of the enzyme system being the key component of it. It is known that dehydrogenases have been one of the most important enzymes the ensure the biological process. The complicated mechanism of the action of enzymes has not been fully described so far however, in the practice of monitoring biological treatment processes, an indicator of the dehydrogenase activity of sludge is used. The research results provided for supplementing the available information with actual data on the interdependence of the level of dehydrogenase activity of sludge and indicators of individual process parameters of biological treatment. It was shown that the mode of operation of aeration tanks (organic matter load on sludge, dose of activated sludge, etc.) and the values of the initial dehydrogenase activity and dehydrogenase activity of the same sludge sample with weakly concentrated solution (DASН2О) are interconnected and depend on the organic load on sludge. The results of the study can be used to control the biological process of wastewater treatment.The biological method of wastewater treatment is a comprehensive multicomponent process the activities of the enzyme system being the key component of it. It is known that dehydrogenases have been one of the most important enzymes the ensure the biological process. The complicated mechanism of the action of enzymes has not been fully described so far however, in the practice of monitoring biological treatment processes, an indicator of the dehydrogenase activity of sludge is used. The research results provided for supplementing the available information with actual data on the interdependence of the level of dehydrogenase activity of sludge and indicators of individual process parameters of biological treatment. It was shown that the mode of operation of aeration tanks (organic matter load on sludge, dose of activated sludge, etc.) and the values of the initial dehydrogenase activity and dehydrogenase activity of the same sludge sample with weakly concentrated solution (DASН2О) are interconnected and depend on the organic load on sludge. The results of the study can be used to control the biological process of wastewater treatment.


1977 ◽  
Vol 12 (1) ◽  
pp. 191-212
Author(s):  
B. Volesky ◽  
Q. Samak ◽  
P. Waller

Abstract Review of the available results appearing in the recent literature is presented focusing particularly upon the effects of metallic ions such as Cr, Cu, Zn, Cd, Hg, V, Zn, Ni and Co. Some original data involving the effects of Na are presented and discussed. Development of parameters used in evaluating the influence of toxic or inhibitory species on the mixed microbial population of an activated sludge system is of crucial importance and different techniques employed such as BOD-COD-TOC-removal rates, Oxygen Uptake Rate, and others are discussed, showing relative inadequacy of currently applied assays. From the data available, certain trends can be discerned. There is a definite threshold concentration for each metallic ion, depending on the organic load of the feed. In the order of increasing toxicity to activated sludge systems reflected in lower BOD removals the following metals have been listed as inhibiting factors at concentrations starting from 1 ppm applied on a continuous basis: hexavalent chromium, cobalt, zinc, cadmium, trivalent chromium, copper and nickel. Metals in combination have not been reported to exhibit any significantly different effects as compared to those observed with individually introduced metallic ions. Tolerance of some activated sludge systems to shock loadings by various inorganic ions and metals is reviewed. The conclusions are of particular importance for estimating the performance of biox systems handling industrial effluents which are likely to contain toxic components of inorganic or metallic nature.


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