Construction of novel electrochemical treatment systems for indigo wastewater and their performance

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Zhijie Huangfu ◽  
Wei Zhang ◽  
Shang Hao ◽  
Mengdi Zhang ◽  
Jiming Yao
Keyword(s):  
Stainless Steel ◽  
Wastewater Treatment ◽  
Sodium Chloride ◽  
Sodium Sulfate ◽  
Removal Rate ◽  
Pure Aluminum ◽  
Electrochemical Treatment ◽  
Treatment System ◽  
Content Type ◽  
Decolorization Rate

Purpose This study aims to evaluate the efficiency of metal electrode and electrolytes on the electroflocculation of indigo wastewater, produced by printing and dyeing factory, and to optimize the treatment system. Design/methodology/approach For effective purging, various types of metal electrodes (graphite, pure aluminum and stainless steel) and supporting electrolytes (sodium chloride and sodium sulfate) were selected for electroflocculation experiments. The decolorization rate and chemical oxygen demand (COD) removal rate were characterized. Findings The treatment effects of stainless steel and aluminum were similar, but the dissolution loss of aluminum and the production of flocs greatly limit its application. Electrolytes gave obvious effects to these systems. Sodium sulfate was better than sodium chloride, the decolorization rate was increased by 3.31%, the removal rate of COD in the solution was increased by 28.65% and the weight of flocculation precipitation was reduced by 0.214 g. Research limitations/implications The electrochemical treatment system was constructed to compare and analyze the influence of experimental parameters and to provide a reference for the actual treatment of indigo wastewater. Practical implications Electrochemical flocculation can remove the insoluble indigo solids and it plays a key role in wastewater treatment. Originality/value It is novel to optimize the combination of electrode and electrolyte to improve the efficiency of electroflocculation, which can be widely used in the actual wastewater treatment process.

scholarly journals Use of a duckweed pond for the domestic wastewater polishing in Ilha Solteira, SP, Brazil

2017 ◽  
Vol 28 (4) ◽  
pp. 477-489 ◽  
Author(s):  
Daiane Cristina de Oliveira Garcia ◽  
Liliane Lazzari Albertin ◽  
Tsunao Matsumoto
Keyword(s):  
Wastewater Treatment ◽  
Biomass Production ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Treatment System ◽  
Content Type ◽  
Stabilization Pond ◽  
Domestic Effluent ◽  
Duckweed Pond

Purpose The purpose of this paper is to evaluate the efficiency of a duckweed pond in the polishing of a stabilization pond effluent, as well as quantify its biomass production. Once an adequate destination is given to the produced biomass, the wastewater treatment plant can work in a sustainable and integrated way. Design/methodology/approach The duckweed pond consisted of a tank with volume 0.44 m3, operating in continuous flow with an outflow of 0.12 m3/day and hydraulic retention time of 3.8 days. Effluent samples were collected before and after the treatment, with analyzes made: daily-pH, dissolved oxygen and temperature; twice a week – total nitrogen (TN), total phosphorus (TP) and chemical oxygen demand (COD); and weekly – total solids (TS) and Biochemical Oxygen Demand (BOD5). The duckweeds were collected each for seven days for its production quantification. Findings The highest efficiency of TN, TP, COD, BOD5 and TS removal were of 74.67, 66.18, 88.12, 91.14 and 48.9 percent, respectively. The highest biomass production rate was 10.33 g/m2/day in dry mass. Research limitations/implications There was great variation in biomass production, which may be related to the stabilization pond effluent conditions. The evaluation of the effluent composition, which will be treated with duckweeds, is recommended. Practical implications The evaluated treatment system obtained positive results for the reduction in the analyzed variables concentration, being an efficient technology and with operational simplicity for the domestic effluent polishing. Originality/value The motivation of this work was to bring a simple system of treatment and to give value to a domestic wastewater treatment system in a way that, at the same time the effluent polluter level is reduced and it is also possible to produce biomass during the treatment process.

scholarly journals Burkholderia zhejiangensis sp. nov., a methyl-parathion-degrading bacterium isolated from a wastewater-treatment system

2012 ◽  
Vol 62 (Pt_6) ◽  
pp. 1337-1341 ◽  
Author(s):  
Peng Lu ◽  
Liu-Qiang Zheng ◽  
Jin-Jin Sun ◽  
Hong-Ming Liu ◽  
Shun-Peng Li ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Type Species ◽  
Methyl Parathion ◽  
Treatment System ◽  
Rrna Gene ◽  
The Novel ◽  
Content Type ◽  
Wastewater Treatment System ◽  
Link Type ◽  
Degrading Bacterium

The taxonomic status of a methyl-parathion-degrading strain, OP-1T, isolated from a wastewater-treatment system in China, was determined using a polyphasic approach. The rod-shaped cells were Gram-staining-negative, non-spore-forming and non-motile. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the novel strain belonged to the genus Burkholderia , as it appeared closely related to Burkholderia glathei ATCC 29195T (97.4 % sequence similarity), Burkholderia sordidicola KCTC 12081T (96.5 %) and Burkholderia bryophila LMG 23644T (96.3 %). The major cellular fatty acids, C16 : 0, C17 : 0 cyclo and C18 : 1ω7c, were also similar to those found in established members of the genus Burkholderia . The genomic DNA G+C content of strain OP-1T was 59.4 mol%. The level of DNA–DNA relatedness between the novel strain and the closest recognized species, Burkholderia glathei ATCC 29195T, was only 30 %. Based on the phenotypic, genotypic and phylogenetic evidence, strain OP-1T represents a novel species of the genus Burkholderia , for which the name Burkholderia zhejiangensis sp. nov. is proposed. The type strain is OP-1T ( = CCTCC AB 2010354T = KCTC 23300T).

scholarly journals Wastewater treatment for tofu home industries in Semanan, West Jakarta using electrocoagulation method with electrode al-stainless steel

2021 ◽  
Vol 894 (1) ◽  
pp. 012016
Author(s):  
A Wijaya ◽  
B Iswanto ◽  
M M Sintorini
Keyword(s):  
Stainless Steel ◽  
Wastewater Treatment ◽  
Aquatic Environment ◽  
Environmental Problems ◽  
Cod Removal ◽  
Treatment System ◽  
Detention Time ◽  
Wastewater Treatment System ◽  
Home Industries ◽  
Bod Removal

Abstract Tofu wastewater is dangerous for the aquatic environment because it contains high BOD, COD, and TSS, which will damage life in the river. Tofu home industries in Semanan have not used a proper wastewater treatment system, and this study was conducted to test the electrocoagulation system to reduce the levels of BOD, COD, and TSS. According to several studies, the electrocoagulation system can reduce BOD, COD, and TSS. It is hoped that this electrocoagulation system can solve environmental problems caused by tofu wastewater. From the research that has been done, namely with the stirring variable at a speed of 150 RPM and at a detention time of 10 minutes with a discharge of 0.6 liter/minute, the percentage of COD removal is 36%, the percentage of BOD removal is 27%, and the percentage of TSS removal is 51%. Then on the stirring variable at a speed of 100 RPM and at a detention time of 10 minutes with a discharge of 0.6 liter/minute, the percentage of COD removal is 32%, the percentage of BOD removal is 15%, and the percentage of TSS removal is 58%.

Corrosion fatigue behavior of Al-5Mg coated AISI 316L stainless steel in sodium chloride environments under bending load

2019 ◽  
Vol 66 (1) ◽  
pp. 34-39 ◽  
Author(s):  
Mustafa Öcal ◽  
Recep Sadeler
Keyword(s):  
Stainless Steel ◽  
Sodium Chloride ◽  
316L Stainless Steel ◽  
Fatigue Behavior ◽  
Base Material ◽  
Ambient Air ◽  
Aisi 316L ◽  
Aisi 316L Stainless Steel ◽  
Content Type ◽  
Bending Load

Purpose The purpose of this study is to describe the environmentally assisted cracking (EAC) of AISI 316L stainless steel as bare and coated cases in several corrosion environments. The main purpose of this study is to extend the lifespan of 316L material under corrosive fatigue in sodium chloride environments. Design/methodology/approach Fatigue tests carried out by using a Schenk type plane bending fatigue machine made by Tokyokoki Co. A scanning electron microscope (SEM) was used to observe the fracture surfaces and tested specimen surfaces. The micro-Vickers hardness of specimens was measured by using a PC-controlled Buehler–Omnimet tester. Findings Under reciprocating bending condition (R = −1) the behavior of 316L SS bare samples and 316L SS coated with Al-5%Mg samples were investigated comparatively at room temperature in ambient air and in several corrosion solutions. The results obtained from the data showed that Al-5Mg coating procedure significantly stabilized the 316L SS even in the most aggressive environment 5 per cent NaCl solution as compared with bare samples. Originality/value Al-5Mg coating showed a stable structure under the corrosion liquids used in the experiments. The coating material served as a stable barrier between the base material and the corrosion fluid, thus ensuring a tightness even in long-term tests below the endurance limit.

Performance of anode materials in electrochemical treatment system for indigo dyeing wastewater

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Wei Zhang ◽  
Mengdi Zhang ◽  
Zhijie Huangfu ◽  
Jiming Yao ◽  
Yuan Xie
Keyword(s):  
Anode Materials ◽  
Electrolyte Concentration ◽  
Removal Rate ◽  
Electrochemical Treatment ◽  
Cod Removal ◽  
Aluminum Electrode ◽  
Dyeing Wastewater ◽  
Content Type ◽  
Indigo Dyeing ◽  
Cod Removal Rate

Purpose This study aims to explore suitable anode materials used in the electrochemical system for indigo dyeing wastewater, to achieve optimal treatment performances. Design/methodology/approach The single factor experiment was used to explore the optimum process parameters for electrochemical decolorization of indigo dyeing wastewater by changing the applied voltage, electrolysis time and electrolyte concentration. At the voltage of 9 V, the morphology of flocs with different electrolytic times was observed and the effect of electrolyte concentration on decolorization rate in two electrolyte systems was also investigated. Further analysis of chemical oxygen demand (COD) removal rate, anode weight loss and sediment quantity after electrochemical treatment of indigo dyeing wastewater were carried out. Findings Comprehensive considering the decolorization degree and COD removal rate of the wastewater, the aluminum electrode showed the best treatment effect among several common anode materials. With aluminum electrode as an anode, under conditions of applied voltage of 9 V, electrolysis time of 40 min and sodium sulfate concentration of 6 g/L, the decolorization percentage obtained was of 94.59% and the COD removal rate reached at 84.53%. Research limitations/implications In the electrochemical treatment of indigo dyeing wastewater, the aluminum electrode was found as an ideal anode material, which provided a reference for the choice of anodes. The electrodes used in this study were homogenous material and the composite material anode needed to be further researched. Practical implications It provided an effective and practical anode material choice for electrochemical degradation of indigo dyeing wastewater. Originality/value Combined with the influence of applied voltage, electrolysis time and electrolyte concentration and anode materials on decolorization degree and COD removal rate of indigo dyeing wastewater, providing a better electrochemical treatment system for dyehouse effluent.

scholarly journals Diversity and functional prediction of microbial communities involved in the first aerobic bioreactor of coking wastewater treatment system

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243748
Author(s):  
Jinsi Deng ◽  
Baoshan Zhang ◽  
Junting Xie ◽  
Haizhen Wu ◽  
Zemin Li ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Microbial Community ◽  
Activated Sludge ◽  
Removal Rate ◽  
Treatment System ◽  
Rrna Gene ◽  
Coking Wastewater ◽  
Microbial Composition ◽  
Term Operation ◽  
Wastewater Treatment System

The pre-aerobic process of coking wastewater treatment has strong capacity of decarbonization and detoxification, which contribute to the subsequent dinitrogen of non-carbon source/heterotrophic denitrification. The COD removal rate can reach > 90% in the first aerobic bioreactor of the novel O/H/O coking wastewater treatment system during long-term operation. The physico-chemical characteristics of influent and effluent coking wastewater in the first aerobic bioreactor were analyzed to examine how they correlated with bacterial communities. The diversity of the activated sludge microbial community was investigated using a culture-independent molecular approach. The microbial community functional profiling and detailed pathways were predicted from the 16S rRNA gene-sequencing data by the PICRUSt software and the KEGG database. High-throughput MiSeq sequencing results revealed a distinct microbial composition in the activated sludge of the first aerobic bioreactor of the O/H/O system. Proteobacteria, Bacteroidetes, and Chlorobi were the decarbonization and detoxification dominant phyla with the relative abundance of 84.07 ± 5.45, 10.89 ± 6.31, and 2.96 ± 1.12%, respectively. Thiobacillus, Rhodoplanes, Lysobacter, and Leucobacter were the potential major genera involved in the crucial functional pathways related to the degradation of phenols, cyanide, benzoate, and naphthalene. These results indicated that the comprehensive understanding of the structure and function diversity of the microbial community in the bioreactor will be conducive to the optimal coking wastewater treatment.

Efficient degradation of indigo wastewater by one-step electrochemical oxidation and electro-flocculation

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Weiwei Lv ◽  
Zhijie Huangfu ◽  
Kangkang Wang ◽  
Wei Zhang ◽  
Jiming Yao
Keyword(s):  
Single Cell ◽  
Electrochemical Oxidation ◽  
Removal Rate ◽  
Cod Removal ◽  
Degradation Efficiency ◽  
Dyeing Wastewater ◽  
Content Type ◽  
Decolorization Rate ◽  
One Step ◽  
Cod Removal Rate

Purpose Indirect electrochemical oxidation and electro-flocculation were combined to degrade indigo wastewater. Design/methodology/approach The degradation efficiency of indigo wastewater in single-cell and double-cell were investigated. Based on the previous single factor experiments, the oxidative degradation conditions of indigo wastewater in single cell were optimized by response surface methodology (RSM). The decolorization rate, chemical oxygen demand (COD) removal rate, the contents of flocculation precipitation and indigo were measured and analyzed. Findings The degradation efficiency in single cell was higher than in double cell. The electrolysis conditions were optimized by RSM and the decolorization rate was 99.01% with COD removal rate of 60.34% and conductivity of 89.75 mS/cm. The amount of flocculated precipitation decreased by 53.33% and the indigo increased by 86.34%. The content of Na and S decreased by 12.13 and 6.49%, respectively. The ratio of Fe3+ to Fe2+ in the solution was 4.62:1, indicating that most of the iron dropped on the electrode sheet was converted to Fe3+. Research limitations/implications The one-step electrochemical oxidation and flocculation method with the advantages of simple operation and environmental protection, provided a reference for the actual treatment of dyeing wastewater. Practical implications Combining the electrochemical flocculation and oxidation provided an efficient and practical solution for degradation of indigo wastewater. Originality/value Combining the advantages of electrochemical oxidation and electroflocculation, the application of electrochemistry in printing and dyeing wastewater treatment technology has been expanded.

Hydrogen Embrittlement of Type 410 Stainless Steel in Sodium Chloride, Sodium Sulfate, and Sodium Hydroxide Environments at 90°C

CORROSION ◽  
1997 ◽  
Vol 53 (6) ◽  
pp. 499-504 ◽  
Author(s):  
J. G. Gonzalez-Rodriguez ◽  
V. M. Salinas-Bravo ◽  
A. Martinez-Villafañe
Keyword(s):  
Stainless Steel ◽  
Sodium Chloride ◽  
Hydrogen Embrittlement ◽  
Sodium Hydroxide ◽  
Sodium Sulfate
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