scholarly journals Study on Chromaticity Removal from Mineral Processing Wastewater with Salicylic Hydroxamic Acid by Granular Activated Carbon Catalyzed Ozonation

Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 359
Author(s):  
Liping Zhang ◽  
Shengnian Wu ◽  
Nan Zhang ◽  
Ruihan Yao ◽  
Eryong Wu
Keyword(s):  
Activated Carbon ◽  
Reaction Time ◽  
Hydroxamic Acid ◽  
Ph Value ◽  
Oxygen Demand ◽  
Granular Activated Carbon ◽  
Mineral Processing ◽  
Ultraviolet Absorption Spectrum ◽  
Experimental Conditions ◽  
Removal Ratio

Salicylic hydroxamic acid is a novel flotation reagent used in mineral processing. However, it impacts the flotation wastewater leaving behind high chromaticity which limits its reuse and affects discharge for mining enterprises. This study researched ozonation catalyzed by the granular activated carbon (GAC) method to treat the chromaticity of the simulated mineral processing wastewater with salicylic hydroxamic acid. The effects of pH value, ozone (O3) concentration, GAC dosage, and reaction time on chromaticity and chemical oxygen demand (CODCr) removal were discussed. The results of individual ozonation experiments showed that the chromaticity removal ratio reached 79% and the effluent chromaticity exceeded the requirement of reuse and discharge when the optimal experimental conditions were pH value 3, ozone concentration 6 mg/L, and reaction time 40 min. The orthogonal experimental results of catalytic ozonation with GAC on chromaticity removal explained that the chromaticity removal ratio could reach 96.36% and the chromaticity of effluent was only 20 when the optimal level of experimental parameters was pH value 2.87, O3 concentration 6 mg/L, GAC dosage 0.06 g/L, reaction time 60 min respectively. The degradation pathway of salicylic hydroxamic acid by ozonation was also considered based on an analysis with ultraviolet absorption spectrum and high-performance liquid chromatography (HPLC).

scholarly journals Research on treatment and mechanism of salicylhydroxamic acid flotation wastewater by O3-BAF process

2020 ◽  
Vol 82 (5) ◽  
pp. 861-876
Author(s):  
Liping Zhang ◽  
Shengnian Wu ◽  
Jun Xiang ◽  
Xiaofei Jiao ◽  
Jing Wang
Keyword(s):  
Reaction Time ◽  
Ph Value ◽  
Degradation Mechanism ◽  
Oxygen Demand ◽  
Organic Load ◽  
Combined Process ◽  
Salicylhydroxamic Acid ◽  
Removal Ratio ◽  
Optimal Experiment ◽  
Water Ratio

Abstract Salicylhydroxamic acid is an effective and selective collector for tungsten and molybdenum ores. However, the salicylhydroxamic acid flotation wastewater discharge may cause damage to the water environment for the residual processing reagents with poor biodegradability. Combined O3 and biological aerated filter (BAF) has a well-known potential for removing refractory or toxic organic pollutants. Combined process of O3 and BAF (O3-BAF) was applied to treat the simulated wastewater from W-Mo mineral processing in this study. Compared single ozonation to O3-BAF, various influencing factors were discussed like O3 dosage, reaction time, initial pH value, gas–water ratio and organic loading. Meanwhile, degradation mechanism of salicylhydroxamic acid was reduced. Under the optimal experiment conditions as pH value 8, O3 dosage 1.3 mg·L−1, reaction time 15 min, the five-day biochemical oxygen demand (BOD5)/chemical oxygen demand of potassium dichromate (CODCr) value increased to from 0.19 to 0.35. The effluent was pumped to the following BAF process, when the optimal experiment conditions was organic load = 0.82 kgCODCr (m−3·d−1), gas-water ratio = 6:1, CODCr concentration of effluent was 28.92 mg·L−1 and the removal ratio was 86.26%, while the removal ratio could higher to 91.12% for the O3-BAF combined process. The effluent could meet the discharge and reuse emission standards requirements in China. UV-vis absorption spectra and high performance liquid chromatography showed the degradation pathway of salicylhydroxamic acid by ozone oxidation was salicylhydroxamic acid → salicylic acid + hydroxylamine → catechol → maleic → small molecular organic acid → carbon dioxide + water.

scholarly journals Viability of a Single-Stage Unsaturated-Saturated Granular Activated Carbon Biofilter for Greywater Treatment

2020 ◽  
Vol 12 (21) ◽  
pp. 8847
Author(s):  
Ahmed Sharaf ◽  
Bing Guo ◽  
David C. Shoults ◽  
Nicholas J. Ashbolt ◽  
Yang Liu
Keyword(s):  
Activated Carbon ◽  
Removal Rate ◽  
Feeding Strategy ◽  
Oxygen Demand ◽  
Granular Activated Carbon ◽  
Complete Removal ◽  
Single Stage ◽  
Chemical Oxygen Demand Removal ◽  
Over Time ◽  
Sewage Source

Compared with conventionally collected sewage, source-diverted greywater has a higher potential for on-site treatment and reuse due to its lower contaminant levels and large volume. A new design of granular activated carbon (GAC) biofilters was developed by incorporating unsaturated and saturated zones in a single stage to introduce an efficient, passive, and easy-to-operate technology for greywater on-site treatment at the household scale. The design was customized for its intended application considering various aspects including the reactor’s configuration, packing media, and feeding strategy. With the highest hydraulic and organic loadings of 1.2 m3 m−2 d−1 and 3.5 kg COD m−2 d−1, respectively, and the shortest retention time of 2.4 h, the system maintained an average total chemical oxygen demand removal rate of 94% with almost complete removal of nutrients throughout its 253 days of operation. The system showed a range of reduction efficacy towards five surrogates representing viruses, bacteria, and Cryptosporidium and Giardia (oo)cysts. A well-functioning biofilm was successfully developed, and its mass and activity increased over time with the highest values observed at the top layers. The key microbes within the biofilter were revealed. Feasibility of the proposed technology was investigated, and implications for design and operation were discussed.

Successful treatment of high azo dye concentration wastewater using combined anaerobic/aerobic granular activated carbon-sequencing batch biofilm reactor (GAC-SBBR): simultaneous adsorption and biodegradation processes

2013 ◽  
Vol 67 (8) ◽  
pp. 1816-1821 ◽  
Author(s):  
E. Hosseini Koupaie ◽  
M. R. Alavi Moghaddam ◽  
S. H. Hashemi
Keyword(s):  
Activated Carbon ◽  
High Performance ◽  
Batch Reactor ◽  
Oxygen Demand ◽  
Microscopic Analysis ◽  
Granular Activated Carbon ◽  
Biofilm Reactor ◽  
Treatment System ◽  
Electron Microscopic ◽  
Sequencing Batch Biofilm Reactor

The application of a granular activated carbon-sequencing batch biofilm reactor (GAC-SBBR) for treatment of wastewater containing 1,000 mg/L Acid Red 18 (AR18) was investigated in this research. The treatment system consisted of a sequencing batch reactor equipped with moving GAC as biofilm support. Each treatment cycle consisted of two successive anaerobic (14 h) and aerobic (8 h) reaction phases. Removal of more than 91% chemical oxygen demand (COD) and 97% AR18 was achieved in this study. Investigation of dye decolorization kinetics showed that the dye removal was stimulated by the adsorption capacity of the GAC at the beginning of the anaerobic phase and then progressed following a first-order reaction. Based on COD analysis results, at least 77.8% of the dye total metabolites were mineralized during the applied treatment system. High-performance liquid chromatography analysis revealed that more than 97% of 1-naphthyalamine-4-sulfonate as one of the main sulfonated aromatic constituents of AR18 was removed during the aerobic reaction phase. According to the scanning electron microscopic analysis, the microbial biofilms grew in most cavities and pores of the GAC, but not on the external surfaces of the GAC.

Coupling of anodic oxidation and adsorption by granular activated carbon for chemical oxygen demand removal from 4,4′-diaminostilbene-2,2′-disulfonic acid wastewater

2010 ◽  
Vol 62 (11) ◽  
pp. 2669-2677 ◽  
Author(s):  
Lizhang Wang ◽  
Yuemin Zhao
Keyword(s):  
Activated Carbon ◽  
Chemical Oxygen Demand ◽  
Residence Time ◽  
Applied Voltage ◽  
Oxygen Demand ◽  
Granular Activated Carbon ◽  
Cod Removal ◽  
Disulfonic Acid ◽  
High Concentration ◽  
Solution Ph

Experiments were performed to reduce chemical oxygen demand (COD) from 4,4′-diaminostilbene-2,2′-disulfonic (DSD) acid manufacturing wastewater using electrochemical oxidation coupled with adsorption by granular activated carbon. The COD removal is affected by the residence time and applied voltage. When the residence time is increased, lower value of COD effluent could be obtained, however, the average current efficiency (ACE) decreased rapidly, and so does the applied voltage. In addition, aeration could effectively enhance COD removal efficiency and protect anodes from corrosion. Furthermore, the acidic condition is beneficial to the rapid decrease of COD and the values of pH effluent are independent of the initial solution pH. The optimization conditions obtained from these experiments are applied voltage of 4.8 V, residence time of 180 min and air–liquid ratio of 4.2 with the COD effluent of about 690 mg L−1. In these cases, the ACE and energy consumption are 388% and 4.144 kW h kg−1 COD, respectively. These perfect results from the experiments illustrate that the combined process is a considerable alternative for the treatment of industrial wastewater containing high concentration of organic pollutants and salinity.

Study on the Model of Limonite-TiO2 Combined Microspheres Photolysising Phenol in Source Water

2012 ◽  
Vol 518-523 ◽  
pp. 121-124
Author(s):  
Hong Xia Xia ◽  
Qi Hong Zhu
Keyword(s):  
Reaction Time ◽  
Light Intensity ◽  
Ph Value ◽  
Removal Rate ◽  
Source Water ◽  
Quadratic Regression ◽  
Solution Ph ◽  
Experimental Conditions ◽  
Orthogonal Regression ◽  
Single Factor Experiment

This paper investigates the effect of Limonite/TiO2 combined microspheres dosage,solution pH, reaction time,light intensity on the removal rate of phenol in source water.Based on the single factor experiment, the experimental conditions are optimized by quadratic regression orthogonal rotation combination design.The quadratic orthogonal regression model of removal rate of phenol(y) to four factors of Limonite/TiO2 combined microspheres dosage(x1),pH(x2),reaction time (x3)and light intensity (x4) is established as Y=88.64+4.43X1+ 6.69X3+3.75X4-4.79X12-13.20X22-4.21X32-2.69X42+8.06X1X2-6.76X1X3-4.45X1X4.It can conclude from the model that when Limonite/TiO2 combined microspheres dosage is 1.5583g,solution pH value is 4.5095,reaction time is 102.12min,light intensity is 1710.8（x10 lux）,the yield(y) reaches the maximal(95.83%) and consistent with the confirmatory experiment result..

Study on Hair Dyeing Wastewater by Fenton Oxidation Method

2014 ◽  
Vol 522-524 ◽  
pp. 168-171
Author(s):  
Jun Yin ◽  
Wei Liu ◽  
Yan Kai ◽  
Wan Yao Wang ◽  
Liang Liang
Keyword(s):  
Wastewater Treatment ◽  
Reaction Time ◽  
Organic Pollutants ◽  
Ph Value ◽  
Fenton Oxidation ◽  
Raw Water ◽  
Dyeing Wastewater ◽  
Fenton Reagent ◽  
Experimental Conditions ◽  
Oxidation Method

Hair dyeing wastewater is produced in coloring process. Its composition is complicated,in which contains a large number of organic pollutants and high color. Hair dyeing wastewater treatment can be effectively treated by Fenton oxidation method. The experiment results show that hair dyeing wastewater is treated by Fenton oxidation in this thesis. Fenton reagent is affected by hair dyeing wastewater, pH reaction time and many other factors. When raw water COD is 3800mg/L and chroma is 1210 times, by using Fenton oxidation method determine best experimental conditions: concentration of H2O2 is 24.5ml（30%H2O2), pH value is 3.0, nH2O2/nFe2+ is 7, reaction time is 60 min. Under the reaction condition , experimental results show that COD and color removal rates were 91.2% and 93.2% in hair dyeing wastewater by Fenton oxidation.

Study on Microwave Combined with Active Carbon for the COD Remove of Amoxicillin Wastewater

2013 ◽  
Vol 295-298 ◽  
pp. 1348-1352 ◽  
Author(s):  
Quan Li Feng ◽  
Xue Qian Wang ◽  
Yu Jia ◽  
Ping Ning
Keyword(s):  
Activated Carbon ◽  
Active Carbon ◽  
Ph Value ◽  
Irradiation Time ◽  
Granular Activated Carbon ◽  
Cod Removal ◽  
Removal Rates

This paper makes the amoxicillin production wastewater as the research target and uses the microwave-activated carbon to treat this kind of wastewater. The results show that 6g of the 60 purpose granular activated carbon mixed with 50ml of the wastewater that diluted 10 times and the pH value is 9 under the condition that irradiated power up to 480W and the irradiation time for 7min, the COD removal rates is up to 96.38% and the effluent COD value is 48.28mg/L.

Study on Preparation of Modified Nano-TiO2 and its Application in Photocatalytic Treatment Wastewater Containing Cd2+

2011 ◽  
Vol 347-353 ◽  
pp. 733-737 ◽  
Author(s):  
Xiao Cai Yu ◽  
Peng Fei Zhu ◽  
Yue Xia Chen ◽  
Jun Wang ◽  
Zong Fu An
Keyword(s):  
Reaction Time ◽  
Ph Value ◽  
Raw Materials ◽  
Removal Rate ◽  
Tetrabutyl Titanate ◽  
Photocatalytic Reaction ◽  
Nano Tio2 ◽  
Experimental Conditions ◽  
Cadmium Ions ◽  
Uv Excitation

Nano-Sn0.25Ti0.75O2 was prepared with hydrothermal method using tetrabutyl titanate as one of the primary raw materials. The products were characterized by XRD and SEM, which revealed that the crystal structure of Sn4+-doped nano-TiO2 is rutile, and the nanoparticles diameter was 14.49nm. Photocatalytic treatment the machining wastewater containing cadmium ions with the UV excitation by Nano-Sn0.25Ti0.75O2 was investigated. The experimental results show that Nano-Sn0.25Ti0.75O2 can be used as photocatalyst to removal Cd2+ from the wastewater effectively with the UV excitation. The wastewater pH value, the initial concentration of Cd2+, the amount of catalyst，the reaction time and other factors affect the efficiency of photocatalytic treatment significantly. The optimization experimental conditions for photocatalytic treatment wastewater containing cadmium ions are as follows, when the concentration of Cd2+ in the wastewater is 20mg/L, amount of Sn0.25Ti0.75O2 is 2g/L, pH in wastewater is 7 and the photocatalytic reaction time is 2h, the removal rate of Cd2+ from the wastewater is up to 98.4%.

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