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51.
Electrochemical oxidation of polyethylene glycol (PEG) in an acidic(pH 0.18 to 0.42) and high ionic strength electroplating solution was investigated. The electroplating solution is a major source of wastewater in the printing wiring board industry. A paraffin composite copper hexacyanoferrate modified(PCCHM) electrode was used as the anode and a bare graphite electrode was used as the cathode. The changes in PEG and total organic carbon (TOC) concentrations during the course of the reaction were monitored. The efficiency of the PCCHM anode was compared with bare graphite anode and it was found that the former showed significant electrocatalytic property for PEG and TOC removal. Chlorides present in the solution were found to contribute significantly in the overall organic removal process. Short chain organic compounds like acetic acid, oxalic acid, formic acid and ethylene glycol formed during electrolysis were identified by HPLC method. Anode surface area and applied current density were found to influence the electro-oxidation process, in which the former was found to be dominating. Investigations of the kinetics for the present electrochemical reaction suggested that the two stage first-order kinetic model provides a much better representation of the overall mechanism of the process if compared to the generalized kinetic model. 相似文献
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Banu JR Yeom IT Esakkiraj S Kumar N Logakanthi S 《Journal of environmental biology / Academy of Environmental Biology, India》2008,29(2):143-146
Sago, the tapioca starch is manufactured by over 800 small-scale units located in the Salem district, Tamil Nadu, India. During the processing of sago it generates huge quantities of biodegradable solid waste, as crushed tubers. In present study an attempt was made to convert these biodegradable solid sago tubers into value added compost using an exotic earthworm, Eudrilus eugeniae. The experiments were carried out in a plastic tray at various concentrations of sago-sludge (50% 75% and 100%) for a period of 90 days. During the vermicomposting, data were collected on life form (cocoon, non clitellates, clitellates) of earthworm and it was found to be high in 50% followed by 75% and 100% concentrations. Chemical analysis of worked substrates showed a step wise increase of nitrogen and phosphorus. The fold increase of phosphorus and nitrogen were found to be high for sago-sludge undergoing vermicomposting than the control. During the composting period the organic carbon decreased from its initial value of 58, 76 and 107 mg/kg to 21, 24 and 65 mg/kg for 50, 70 and 100%, respectively The microbial analysis showed that after 75 days of composting, their population stabilized and further increase in composting period did not increase their population size. The results indicate that 50% and 75% concentration of sludge mixed with bedding material was ideal for the vermicomposting. 相似文献
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Kumar Sarangi Prakash Subudhi Sanjukta Bhatia Latika Saha Koel Mudgil Divya Prasad Shadangi Krushna Srivastava Rajesh K. Pattnaik Bhabjit Arya Raj Kumar 《Environmental science and pollution research international》2023,30(4):8526-8539
Environmental Science and Pollution Research - The major global concern on energy is focused on conventional fossil resources. The burning of fossil fuels is an origin of greenhouse gas emissions... 相似文献
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Muthukkumar Thillainayagam Krishnamoorthy Venkatesan Rana Dipak Saravanan Subramani Balaji Sethuramasamyraja Rajesh Kumar Babu 《Environmental science and pollution research international》2017,24(20):16725-16734
In the Indian agricultural sector, millions of diesel-driven pump-sets were used for irrigation purposes. These engines produce carcinogenic diesel particulates, toxic nitrogen oxides (NOx), and carbon monoxide (CO) emissions which threaten the livelihood of large population of farmers in India. The present study investigates the use of n-propanol, a less-explored high carbon bio-alcohol that can be produced by sustainable pathways from industrial and crop wastes that has an attractive opportunity for powering stationary diesel engines meant for irrigation and rural electrification. This study evaluates the use of n-propanol addition in fossil diesel by up to 30% by vol. and concurrently reports the effects of exhaust gas recirculation (EGR) on emissions of an agricultural DI diesel engine. Three blends PR10, PR20, and PR30 were prepared by mixing 10, 20, and 30% by vol. of n-propanol with fossil diesel. Results when compared to baseline diesel case indicated that smoke density reduced with increasing n-propanol fraction in the blends. PR10, PR20, and PR30 reduced smoke density by 13.33, 33.33, and 60%, respectively. NOx emissions increased with increasing n-propanol fraction in the blends. Later, three EGR rates (10, 20, and 30%) were employed. At any particular EGR rate, smoke density remained lower with increasing n-propanol content in the blends under increasing EGR rates. NOx reduced gradually with EGR. At 30% EGR, the blends PR10, PR20, and PR30 reduced NOx emissions by 43.04, 37.98, and 34.86%, respectively when compared to baseline diesel. CO emissions remained low but hydrocarbon (HC) emissions were high for n-propanol/diesel blends under EGR. Study confirmed that n-propanol could be used by up to 30% by vol. with diesel and the blends delivered lower soot density, NOx, and CO emissions under EGR. 相似文献
55.
Reddy KJ Kumar JR Ramachandraiah C Reddy SA Reddy AV 《Environmental monitoring and assessment》2008,136(1-3):337-346
N-Ethyl-3-cabazolecarboxaldehydethiosemicarbazone (ECCT) is proposed as a new, sensitive and selective complexing reagent
for the separation and extractive spectrophotometric determination of palladium(II) at pH: 4.0 to form a yellowish orange
colored 1:1 chelate complex, which is very well extracted in to n-butanol. The absorbance was measured at a maximum wavelength,
410 nm. This method obeys Beer’s law in the concentration range 0.0–6.6 μg mL−1 and the correlation coefficient of Pd(II)-ECCT complex is 0.998, which indicates an excellent linearity between the two variables
with good molar absorptivity and Sandell’s sensitivity, 1.647 × 104 l mol−1cm−1, 6.49 × 10−3 μg cm−2, respectively. The instability constant of complex calculated from Edmond’s method, 2.724 × 10−5 was in good agreement with the value calculated from Asmus’ method 2.624 × 10−5, at room temperature. The precision and accuracy of the method is checked with calculation of relative standard deviation
(n = 5), 0.839. Edmond’s method was observed to be a more selective method in the presence of EDTA, oxalate and phosphate ions.
The method was successfully applied for the determination of Pd(II) in water samples, synthetic mixtures and hydrogenation
catalysts, employing an atomic absorption spectrometer for comparing these results. 相似文献
56.
Jose J Giridhar R Anas A Loka Bharathi PA Nair S 《Environmental pollution (Barking, Essex : 1987)》2011,159(10):2775-2780
Over the past three decades heavy metal pollution has increased substantially in Cochin estuary, south west coast of India. Here we studied the distribution, diversity and enzyme expression profile of culturable microbial population along a pollution gradient. The distribution of resistance against 5 mM concentration of Zn, Co, Ni and Cu was observed among 90-100% of bacterial isolates retrieved from highly polluted Eloor, whereas it was less than 40% in Vypin and Munambam. Similarly, there was a difference in the distribution and diversity of bacterial phyla with predominance of Proteobacteria in Eloor and Firmicutes in Munambam and Vypin. We observed that 75-100% of the organisms retrieved from Eloor had low levels of expression for hydrolytic enzyme. In conclusion, the heavy metal pollution in Cochin estuary brought in reduction/adaptation in the distribution, diversity and enzyme expression profile of bacteria, which may impart adverse impacts on ecosystem functioning. 相似文献
57.
Bioavailability and risk assessment of trace metals in sediments of a high-altitude eutrophic lake,Ooty, Tamil Nadu,India 总被引:1,自引:0,他引:1
Parthasarathy Purushothaman Asok Manju Ranjan Rajesh Kumar Swain Sujit Kumar 《Environmental science and pollution research international》2021,28(15):18616-18631
Environmental Science and Pollution Research - Ooty lake, in the southern part of India, has raised huge concern about the role of metals in a lake due to increasing anthropogenic activities.... 相似文献
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J Rajesh Banu Essaki Raj S Kaliappan Dieter Beck Ick-Tae Yeom 《Journal of environmental biology / Academy of Environmental Biology, India》2007,28(4):741-745
Overtones of fruit wastes accumulate daily in the city of Chennai, India and there is an urgent need to develop, assess and use ecofriendly methods to dispose them. Presently an attempt has been made to study solid state biomethanation of fruit wastes using a laboratory scale anaerobic digester Fruit wastes containing 3%, 4% and 5% solids were used for experimentation. Daily and cumulative production of biogas produced during the study was recorded. Increase in nitrogen, phosphorus and potassium content in the feed was observed during the digestion. During the study the biogas generation increased with increase in total solids. While the gas generation was 0.006 m3/day/m3 of the reactor volume when the solid content was 3% the corresponding values for 4% and 5% solids were 0.27and 0.35 m3 respectively Varying TS 3% to 4% has no effect on fermentation stability and pH remained between 6.8 and 7.4, but an inhibition of methanogenic bacteria was observed for TS 5%. The overall performance of the reactor was depressed by changing feed concentration from 3% to 5%. Experiments with 4% initial solid contend was ideal for solid-state biomethanation. 相似文献