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21.
Balu Soundara Vasudevan Mangottiri Pillai Rakesh J. Bhuvaneshwari S. Preethi V. Jeevanantham V. 《Environmental science and pollution research international》2022,29(57):85839-85841
Environmental Science and Pollution Research - 相似文献
22.
Sewage sludge contains rich organic matter and nutrients essential for the growth of plants but the presence of toxic heavy metals restricts its land application. To overcome this, the study aims an eco-friendly approach for leaching out heavy metals. Sewage sludge from sewage treatment plant, Chennai, India was characterised. The analysis of total heavy metal concentration was done by digesting in nitric acid and different forms were extracted by community bureau of reference sequential method. Heavy metals: As, Cd, Cr, Cr, Ni, Pb and Zn were determined using inductively coupled plasma optical emission spectrometry Perkin Elmer Optima 5300 DV. The experimental set-up for heavy metal leaching was held for five consecutive days at different concentrations of humic acid (0.1%, 0.5% and 1%) at varied pH (5–9). Results revealed that at the end of fifth day at pH 8, 1% humic acid is capable of leaching out 75.5% cadmium, 66.0% nickel, 52.0% lead, 51.2% zinc, 31.2% copper and 8.5% cadmium from sewage sludge. Statistically positive correlation (0.7088) existed between the percentage of heavy metals leached out and the sum of soluble and reducible fractions. Thus, from ecological point of view, humic acid can be used to leach out heavy metals from sewage sludge serving the need in restoration of soil fertility upon land application. 相似文献
23.
This study provides an electrocoagulation process for the removal of copper from water using mild steel and stainless steel as anode and cathode, respectively. The effect of different operating parameters and coexisting ions on the removal efficiency of copperwas investigated. The results showed that the optimum removal efficiency of 97.8% was achieved at a current density of 0.02 A/dm2 and a pH of 7.0. The adsorption of copper, preferably fitting the Langmuir adsorption isotherm, suggests monolayer coverage of adsorbed molecules. First-and second-order rate equations and Elovich and intraparticle diffusion models were applied to study adsorption kinetics. The adsorption process follows the second-order kinetics model with good correlation. Temperature studies showed that adsorption was endothermic and spontaneous in nature. 相似文献
24.
Ramakrishnan Kamaraj Pandian Ganesan Jothinathan Lakshmi Subramanyan Vasudevan 《Environmental science and pollution research international》2013,20(1):399-412
Purpose and aim
In general, direct current (DC) is used in an electrocoagulation processes. In this case, an impermeable oxide layer may form on the cathode as well as corrosion formation on the anode due to oxidation. This prevents the effective current transfer between the anode and cathode, so the efficiency of electrocoagulation processes declines. These disadvantages of DC have been diminished by adopting alternating current (AC) in electrocoagulation processes. The main objective of this study is to investigate the effects of AC and DC on the removal of copper from water using magnesium alloy as anode and cathode.Materials and methods
Magnesium alloy of size 2.0 dm2 was used as anode and as cathode. To optimize the maximum removal efficiency, different parameters like effect of initial concentration, effect of temperature, pH, and effect of current density were studied. Copper adsorbed magnesium hydroxide coagulant was characterized by SEM, EDAX, XRD, and FTIR.Results
The results showed that the optimum removal efficiency of copper is 97.8 and 97.2 % with an energy consumption of 0.634 and 0.996 kWh/m3 at a current density of 0.025 A/dm2, pH of 7.0 for AC and DC, respectively. The adsorption of copper is preferably fitting the Langmuir adsorption isotherm for both AC and DC respectively. The adsorption process follows the second-order kinetics model with good correlation. Temperature studies showed that adsorption was endothermic and spontaneous in nature.Conclusions
The magnesium hydroxide generated in the cell removes the copper present in the water, reducing the copper concentration to less than 1 mg/L, making it safe for drinking. The results of the scale-up study show that the process was technologically feasible. 相似文献25.
This article reviews both the pollution by the electrochemical industry and the use of electrochemistry to clean water. Main pollutants include Pd, Cd, Ni, Hg and other metals and cyanide as well as organic pollutants. The cause for water pollution by electrochemistry is due to the effluents from different electrochemical industries such as mercury from chlor-alkali industry; lead, cadmium and mercury from battery industry; heavy metals and organic contaminants from electroplating wastes; contaminants from corrosion processes; and persistent organic pollutants from the synthesis and use of pesticides, dyes and pharmaceuticals. Most pollutants can be successfully eliminated or converted to non-toxic materials by methods based on the electrochemical principles. Electrochemical depolluting methods are mainly electrodialysis, electrocoagulation, electroflotation, anodic processes, cathodic processes and electrochemical advanced oxidation processes. 相似文献
26.
Vasudevan Mangottiri Natarajan Narayanan Selvi Sugashini Masillamani Ravikumar Kesavan Rajendran Arun Dharshini Bagavathi Anushya Banu 《Environmental science and pollution research international》2022,29(57):86126-86155
Environmental Science and Pollution Research - The present study focuses on the impact of early imposed lockdowns and following unlocking phases on the status of air quality in six Tier-I and nine... 相似文献
27.
Rout Sonam Priyadarshini Vasudevan Sivaprakasam 《Environmental monitoring and assessment》2022,194(4):1-25
Environmental Monitoring and Assessment - The increased usage of antibiotics over the recent years has been of great concern all over the world. It is estimated that about 100,000 tons to 200,000... 相似文献
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29.
Anirban Dutta Venugopal Vasudevan Lata Nain 《Journal of environmental science and health. Part. B》2016,51(1):24-34
An enrichment culture was used to study atrazine degradation in mineral salt medium (MSM) (T1), MSM+soil extract (1:1, v/v) (T2) and soil extract (T3). Results suggested that enrichment culture required soil extract to degrade atrazine, as after second sequential transfer only partial atrazine degradation was observed in T1 treatment while atrazine was completely degraded in T2 and T3 treatments even after fourth transfer. Culture independent polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) technique confirmed selective enrichment of genus Bacillus along with Pseudomonas and Burkholderia. Degradation of atrazine/metabolites in the industrial wastewater was studied at different initial concentrations of the contaminants [wastewater-water (v/v) ratio: T1, 1:9; T2, 2:8; T3, 3:7; T4, 5:5 and T5, undiluted effluent]. The initial concentrations of atrazine, cyanuric acid and biuret ranged between 5.32 and 53.92 µg mL?1, 265.6 and 1805.2 µg mL?1 and 1.85 and 16.12 µg mL?1, respectively. The enrichment culture was able to completely degrade atrazine, cyanuric acid and biuret up to T4 treatment, while no appreciable degradation of contaminants was observed in the undiluted effluent (T5). Inability of enrichment culture to degrade atrazine/metabolites might be due to high concentrations of cyanuric acid. Therefore, a separate study on cyanuric acid degradation suggested: (i) no appreciable cyanuric acid degradation with accumulation of an unidentified metabolite in the medium where cyanuric acid was supplemented as the sole source of carbon and nitrogen; (ii) partial cyanuric acid degradation with accumulation of unidentified metabolite in the medium containing additional nitrogen source; and (iii) complete cyanuric acid degradation in the medium supplemented with an additional carbon source. This unidentified metabolite observed during cyanuric acid degradation and also detected in the enrichment culture inoculated wastewater samples, however, was degraded up to T4 treatments and was persistent in the T5 treatment. Probably, accumulation of this metabolite inhibited atrazine/cyanuric acid degradation by the enrichment culture in undiluted wastewater. 相似文献
30.
Recovery of hydrogen and removal of nitrate from water by electrocoagulation process 总被引:1,自引:0,他引:1
Jothinathan Lakshmi Ganapathy Sozhan Subramanyan Vasudevan 《Environmental science and pollution research international》2013,20(4):2184-2192
The present study provides an optimization of electrocoagulation process for the recovery of hydrogen and removal of nitrate from water. In doing so, the thermodynamic, adsorption isotherm, and kinetic studies were also carried out. Aluminum alloy of size 2 dm2 was used as anode and as cathode. To optimize the maximum removal efficiency, different parameters like effect of initial concentration, effect of temperature, pH, and effect of current density were studied. The results show that a significant amount of hydrogen can be generated by this process during the removal of nitrate from water. The energy yield calculated from the hydrogen generated is 3.3778 kWh/m3. The results also showed that the maximum removal efficiency of 95.9 % was achieved at a current density of 0.25 A/dm2, at a pH of 7.0. The adsorption process followed second-order kinetics model. The adsorption of NO 3 ? preferably fitting the Langmuir adsorption isotherm suggests monolayer coverage of adsorbed molecules. Thermodynamic studies showed that adsorption was exothermic and spontaneous in nature. The energy yield of generated hydrogen was ~54 % of the electrical energy demand of the electrocoagulation process. With the reduction of the net energy demand, electrocoagulation may become a useful technology to treat water associated with power production. The aluminum hydroxide generated in the cell removes the nitrate present in the water and reduced it to a permissible level making the water drinkable. 相似文献