Template-Type: ReDIF-Article 1.0 Author-Name: Timothy E. Lipman Author-X-Name-First: Timothy E. Author-X-Name-Last: Lipman Author-Name: Jeffrey Lidicker Author-X-Name-First: Jeffrey Author-X-Name-Last: Lidicker Title: Wind-assist marine demonstration for ferries: prospects for saving diesel fuel with wind power Abstract: These sailing vessel testing, data collection and analysis project examined the real world potential for a novel carbon-fibre 'wingsail' technology to reduce fuel use in potential passenger ferryboat applications. The project involved building a carbon fibre, computer-controlled wingsail that was then mounted on a 14-metre trimaran test vessel with a complete instrumentation package. The vessel was then operated on the San Francisco Bay over a three-month period. The test results were conclusive that, for a test vessel travelling at seven knots though water on a particular ferry route, up to 25% to 40% of the fuel burned can be saved through the use of the wingsail, depending on wind speed, with a corresponding reduction in greenhouse gases, toxic and criteria pollutant emissions and fuel costs. The estimated fuel efficiency gains will not necessarily translate directly to those at actual ferryboat service speeds (at 17 or more knots) but are encouraging pending further investigations. Journal: Int. J. of Environmental Technology and Management Pages: 68-83 Issue: 1 Volume: 22 Year: 2019 Keywords: ferryboat; diesel fuel; wind; sail; wing; marine; energy; sustainability; renewable. File-URL: http://www.inderscience.com/link.php?id=101353 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijetma:v:22:y:2019:i:1:p:68-83 Template-Type: ReDIF-Article 1.0 Author-Name: Tsung-Nan Weng Author-X-Name-First: Tsung-Nan Author-X-Name-Last: Weng Author-Name: Chen-Wuing Liu Author-X-Name-First: Chen-Wuing Author-X-Name-Last: Liu Author-Name: Wen-Yao Liu Author-X-Name-First: Wen-Yao Author-X-Name-Last: Liu Title: Correlations between on-site screening methods and laboratory analyses of oil-contaminated fuelling station sites Abstract: In order to assess the potential of soil contamination from petroleum-based products and determine the soil samples required for laboratory analysis, investigators generally use portable instruments such as photo ionisation detectors (PIDs) or flame ionisation detectors (FIDs) for on-site screening. In this study, PIDs, FIDs, and turbidimetric test kits were integratively used to screen 47 soil samples from 28 fuelling station sites suspected of total petroleum hydrocarbon (TPH) contamination. The PIDs and FIDs achieved high accuracy in screening sites contaminated by gasoline (TPH<SUB align="right"><SMALL>C6-C9</SMALL></SUB>); the test kits yielded high accuracy in screening those contaminated by diesel fuel (TPH<SUB align="right"><SMALL>C10-C40</SMALL></SUB>), as well as high correlation with laboratory analysis. Regression analyses showed high coefficients of determination (R<SUP align="right"><SMALL>2</SMALL></SUP>), reaching up to 0.819 (PIDs versus TPH<SUB align="right"><SMALL>C6-C9</SMALL></SUB>), 0.788 (FIDs versus TPH<SUB align="right"><SMALL>C6-C9</SMALL></SUB>), and 0.653 (test kits versus TPH<SUB align="right"><SMALL>C10-C40</SMALL></SUB>). The integration of PIDs, FIDs, and test kits with laboratory analysis can significantly increase the efficiency and accuracy of soil contamination investigations. We suggest that the application of turbidimetric test kits to screen potential oil-contaminated fuelling station sites can produce accurate assessment results. Journal: Int. J. of Environmental Technology and Management Pages: 1-19 Issue: 1 Volume: 22 Year: 2019 Keywords: total petroleum hydrocarbon; TPH; soil contamination; turbidimetric test kits; field screening; fuelling station sites. File-URL: http://www.inderscience.com/link.php?id=101371 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijetma:v:22:y:2019:i:1:p:1-19 Template-Type: ReDIF-Article 1.0 Author-Name: Rajeshwari Chatterjee Author-X-Name-First: Rajeshwari Author-X-Name-Last: Chatterjee Author-Name: Sanat Kumar Mukherjee Author-X-Name-First: Sanat Kumar Author-X-Name-Last: Mukherjee Title: Sustainable development of bio-diesel production for cleaner environment Abstract: Environmental impacts of fossil fuels and their limited supply are driving the development and use of bio-diesel. Globally, bio-diesel is gaining importance because of its environmental advantages. <i>Jatropha curcas</i> has been widely considered as a potential feedstock for the production of bio-diesel in several tropical countries. This study employs a method of data collection that is a face-to-face interview, along with a questionnaire. The questionnaire is designed, taking into consideration, different aspects of sustainable development. The survey is conducted in Kolkata, based on bio-diesel producing companies. Statistical analysis using SPSS version 17 is used for analysing the data collected from different bio-diesel producing companies from respondents of sample size 100 based on the questionnaire. Analysis of primary data collected is evaluated by chi-square and correlation tests. The results indicate that the relationship of design, maintenance, process capability, facility management, transportation, quality, technology, material, and human resource with sustainable development, is statistically significant and positively correlated. The major barriers that industries are facing relate to inadequate quality management, missing engine approvals and high raw material cost. Removal of tax hurdles and supportive legislative measures are the most efficient measures for overcoming these barriers. Journal: Int. J. of Environmental Technology and Management Pages: 20-39 Issue: 1 Volume: 22 Year: 2019 Keywords: bio-diesel; Jatropha; sustainable development; chi-square; co-relation. File-URL: http://www.inderscience.com/link.php?id=101383 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijetma:v:22:y:2019:i:1:p:20-39 Template-Type: ReDIF-Article 1.0 Author-Name: Irvan Dahlan Author-X-Name-First: Irvan Author-X-Name-Last: Dahlan Author-Name: Kan Chee Kit Author-X-Name-First: Kan Chee Author-X-Name-Last: Kit Title: Modelling and simulation of batch adsorption of malachite green using groundnut shell waste-based activated carbon Abstract: Modelling and simulation of batch adsorption in malachite green dye removal using activated carbon prepared from groundnut shell waste was studied. Mathematical model was developed based on a two-resistance model which included external mass transfer coefficient and pore diffusion coefficient that controls the mass transfer process in batch adsorption. MATLAB program was written to solve ordinary differential equation from the model and to estimate mass transfer parameters by matching the simulation data with the experimental data from literature. From the results, it was found that the external mass transfer coefficient <i>k</i><SUB align="right"><SMALL><i>f</i></SMALL></SUB> and pore diffusion coefficient <i>D</i><SUB align="right"><SMALL><i>p</i></SMALL></SUB> were estimated to be 6.2054 × 10<SUP align="right"><SMALL>&minus;2</SMALL></SUP> m/s and 2.2660 × 10<SUP align="right"><SMALL>&minus;10</SMALL></SUP> m<SUP align="right"><SMALL>2</SMALL></SUP>/s, respectively. Using the estimated parameters, simulation results showed that the model provided good correlation with the experimental data based on different initial concentrations. The estimated parameters were used to study the adsorption of dye under different variables such as initial dye concentration, volume of dye solution, adsorbent particle size and mass of adsorbent. It was concluded that the dye removal efficiency was higher for lower initial dye concentration, higher mass of adsorbent, lower volume of dye solution and smaller adsorbent particle size. Journal: Int. J. of Environmental Technology and Management Pages: 40-55 Issue: 1 Volume: 22 Year: 2019 Keywords: adsorption; malachite green dye; activated carbon; groundnut shell waste; mathematical modelling. File-URL: http://www.inderscience.com/link.php?id=101385 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijetma:v:22:y:2019:i:1:p:40-55 Template-Type: ReDIF-Article 1.0 Author-Name: Yanhong Xu Author-X-Name-First: Yanhong Author-X-Name-Last: Xu Author-Name: Guangrong Huang Author-X-Name-First: Guangrong Author-X-Name-Last: Huang Title: Removal of Cr(VI) and Cu(II) from wastewater by an Argopecten irradians shell powder adsorbent Abstract: The ability of the shell powder of <i>Argopecten irradians</i> to remove Cr(VI) and Cu(II) ions from aquatic systems was evaluated. The adsorption efficiency was very high for Cu(II), at approximately 99.04%, while for Cr(VI), it was not higher than 24.03%. The adsorption rate of Cr(VI) was affected by the pH, feeding amount, stirring time, calcination temperature and initial Cr(VI) ion concentration. The experimental results indicate that the optimal Cr(VI) absorption rate was 32.86% of Cr(VI) within 1.5 h at a pH of 3 and a 200 mg/L initial Cr(VI) concentration on shell powder acidifie, using hydrochloric acid and calcination at 300°C to promote adsorption. Langmuir and Freundlich models were used to analyse the isotherm data of Cr(VI) and Cu(II). The Freundlich model was suited to Cr(VI) adsorption, while the Langmuir model fit Cu(II) adsorption. Journal: Int. J. of Environmental Technology and Management Pages: 56-67 Issue: 1 Volume: 22 Year: 2019 Keywords: chromium ion; copper ion; adsorption; wastewater; Argopecten irradians. File-URL: http://www.inderscience.com/link.php?id=101391 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijetma:v:22:y:2019:i:1:p:56-67 Template-Type: ReDIF-Article 1.0 Author-Name: Natiela Caponi Author-X-Name-First: Natiela Author-X-Name-Last: Caponi Author-Name: Gabriela Carvalho Collazzo Author-X-Name-First: Gabriela Carvalho Author-X-Name-Last: Collazzo Author-Name: Julia Da Silveira Salla Author-X-Name-First: Julia Da Silveira Author-X-Name-Last: Salla Author-Name: Sérgio Luiz Jahn Author-X-Name-First: Sérgio Luiz Author-X-Name-Last: Jahn Author-Name: Guilherme Luiz Dotto Author-X-Name-First: Guilherme Luiz Author-X-Name-Last: Dotto Author-Name: Edson Luiz Foletto Author-X-Name-First: Edson Luiz Author-X-Name-Last: Foletto Title: Optimisation of crystal violet removal onto raw kaolin using response surface methodology Abstract: This work aimed to investigate the removal of crystal violet (CV) dye from coloured wastewater using natural kaolin as an adsorbent. In order to investigate the effects of independent variables and to determine the optimum conditions on the dye removal, a 2<SUP align="right"><SMALL>3</SMALL></SUP> central composite design combined with a response surface methodology was employed. Experiments were carried out as a function of agitation rate (80 to 150 rpm), initial dye concentration (50 to 150 mg L<SUP align="right"><SMALL>-1</SMALL></SUP>) and adsorbent dosage (0.5 to 1.0 g L<SUP align="right"><SMALL>-1</SMALL></SUP>). The accuracy of the model was evaluated by employing the analysis of variance (ANOVA). The results revealed a good agreement between the model predicted and the experimental values. Under the optimal experimental conditions, the CV removal efficiency was 71% and the maximum adsorption capacity was 48.8 mg g<SUP align="right"><SMALL>-1</SMALL></SUP>. These results indicated that the kaolin can be successfully applied as a potential low-cost adsorbent for the removal of dyes from coloured wastewaters. Journal: Int. J. of Environmental Technology and Management Pages: 85-100 Issue: 2/3 Volume: 22 Year: 2019 Keywords: adsorption; kaolin; crystal violet; dye; experimental design; response surface; removal; adsorption isotherm; Langmuir model; adsorption capacity. File-URL: http://www.inderscience.com/link.php?id=102197 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijetma:v:22:y:2019:i:2/3:p:85-100 Template-Type: ReDIF-Article 1.0 Author-Name: Abhishek Pratap Singh Author-X-Name-First: Abhishek Pratap Author-X-Name-Last: Singh Author-Name: Pramod Bhatia Author-X-Name-First: Pramod Author-X-Name-Last: Bhatia Title: Numerical simulation of pollutant dispersion in an urban street canyon - effects of elevated metro rail track Abstract: Urban air pollution is one of the unsettled issues in urban development and planning process. Urban street canyons are one of the main focused areas of investigation due to the heavy emission of the pollutants from vehicles. In the present study, the effects of elevated metro rail track (EMRT) on pollutant dispersion phenomena have been studied using computational fluid dynamics (CFD) technique. As a practical application of a CFD model, k-ε turbulence model was applied for airflow modelling. Species transport model was applied for pollutant dispersion modelling. Geometrical configuration of urban street canyon of aspect ratio 'one', with elevated metro rail track, has been considered. Numerical simulations were carried out for perpendicular wind flow. Pollutant concentrations, at various locations of the street canyon, were largely affected by the introduction of elevated metro rail track. These results were compared with the street canyon without elevated metro rail track. It has been observed that the pollutant concentration increased at lower region and decreased at the upper region of the street canyon. Variations were not uniformly distributed in street canyon volume. Contours and pollutant concentrations have been compared and discussed for different sampled locations in the street canyon. Journal: Int. J. of Environmental Technology and Management Pages: 101-114 Issue: 2/3 Volume: 22 Year: 2019 Keywords: pollutant dispersion; air pollution modelling; street canyon; pollutant concentration; elevated rail track. File-URL: http://www.inderscience.com/link.php?id=102198 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijetma:v:22:y:2019:i:2/3:p:101-114 Template-Type: ReDIF-Article 1.0 Author-Name: Olga Trhlíková Author-X-Name-First: Olga Author-X-Name-Last: Trhlíková Title: Identification of the malodour source in a complex office environment using solid-phase microextraction and gas chromatography Abstract: Permanent or recurring malodours invading office rooms have not only detrimental effects on the staff productivity but also on their health directly or through the stress mechanisms. The necessary identification and subsequent neutralisation of the malodour source is complicated by the fact that various malodour sources produce overlapping sets of volatile organic compounds (VOCs). In this contribution we present a combination of solid phase microextraction coupled with gas chromatography with mass detection (SPME/GC-MS) as a useful method for identification of VOCs in a case study of malodour occurrence in office environment. Journal: Int. J. of Environmental Technology and Management Pages: 115-127 Issue: 2/3 Volume: 22 Year: 2019 Keywords: gas chromatography-mass spectrometry; malodours; office environment; stress; volatile organic compounds; VOCs. File-URL: http://www.inderscience.com/link.php?id=102199 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijetma:v:22:y:2019:i:2/3:p:115-127 Template-Type: ReDIF-Article 1.0 Author-Name: Talitha De Andrade Borges Author-X-Name-First: Talitha De Andrade Author-X-Name-Last: Borges Author-Name: Osvaldo Chiavone-Filho Author-X-Name-First: Osvaldo Author-X-Name-Last: Chiavone-Filho Author-Name: Antônio Carlos Silva Costa Teixeira Author-X-Name-First: Antônio Carlos Silva Costa Author-X-Name-Last: Teixeira Author-Name: Edson Luiz Foletto Author-X-Name-First: Edson Luiz Author-X-Name-Last: Foletto Author-Name: Guilherme Luiz Dotto Author-X-Name-First: Guilherme Luiz Author-X-Name-Last: Dotto Author-Name: Cláudio Augusto Oller Do Nascimento Author-X-Name-First: Cláudio Augusto Oller Do Author-X-Name-Last: Nascimento Title: Degradation of thiophanate-methyl fungicide by photo-Fenton process using lab-scale annular and solar tubular reactors Abstract: In this work, thiophanate-methyl fungicide was degraded by the homogeneous photo-Fenton process using lab-scale annular and solar tubular reactors. A UV light was used as artificial irradiation source in the lab-scale reactor. The influence of hydrogen peroxide (H<SUB align="right"><SMALL>2</SMALL></SUB>O<SUB align="right"><SMALL>2</SMALL></SUB>) dosage and initial pollutant concentration on the process efficiency was investigated. Degradation efficiency of thiophanate-methyl fungicide was monitored by measuring the total organic carbon (TOC). The results revealed that the variable H<SUB align="right"><SMALL>2</SMALL></SUB>O<SUB align="right"><SMALL>2</SMALL></SUB> dosage showed remarkable effect on the process efficiency, whereas the fungicide concentration showed little influence. Both reactors showed similar efficiencies, reaching a fungicide mineralisation of 80% at 120 min of reaction time. Therefore, both reactors demonstrate to be effective on the thiophanate-methyl degradation from aqueous solution. Journal: Int. J. of Environmental Technology and Management Pages: 128-137 Issue: 2/3 Volume: 22 Year: 2019 Keywords: annular reactor; degradation; fungicide; H2O2; mineralisation; pesticides; photo-Fenton; solar reactor; thiophanate-methyl; total organic carbon; TOC. File-URL: http://www.inderscience.com/link.php?id=102200 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijetma:v:22:y:2019:i:2/3:p:128-137 Template-Type: ReDIF-Article 1.0 Author-Name: Maria L. Correa Author-X-Name-First: Maria L. Author-X-Name-Last: Correa Author-Name: Daniel I. Arango Author-X-Name-First: Daniel I. Author-X-Name-Last: Arango Author-Name: Jorge H. Sánchez Author-X-Name-First: Jorge H. Author-X-Name-Last: Sánchez Author-Name: Germán C. Quintana Author-X-Name-First: Germán C. Author-X-Name-Last: Quintana Author-Name: Jorge A. Velásquez Author-X-Name-First: Jorge A. Author-X-Name-Last: Velásquez Title: Removal of 2,4-dichlorophenol in a micro-packed bed adsorber by activated carbon from Coffea arabica fruit endocarp Abstract: Activated carbon, obtained by phosphoric acid activation of <i>Coffea arabica</i> fruit endocarp, was used to remove 2,4-dichlorophenol from aqueous solutions in a micro-packed bed adsorber. In batch experiments, effects such as initial concentration, solution's pH, and temperature on adsorption were investigated. It was found that acidic pH is favourable and that the adsorption isotherm is best represented by the Langmuir model. In continuous experiments, the effect of inlet concentration, bed length, and flow rate on the adsorption capacity of the micro-packed bed adsorber were evaluated. Adsorption capacities were higher than those obtained in batch experiments. Inlet concentration and bed length show a significant effect on the adsorption capacity. Breakthrough curves were very well fitted by axial dispersion model. Additionally, breakthrough profiles indicate a particle-controlled process, which suggest a negligible external mass transfer resistance. Journal: Int. J. of Environmental Technology and Management Pages: 138-154 Issue: 2/3 Volume: 22 Year: 2019 Keywords: 2,4-dichlorophenol; 2,4-DCP; activated carbon; micro-packed bed; isotherm; breakthrough; axial dispersion. File-URL: http://www.inderscience.com/link.php?id=102201 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijetma:v:22:y:2019:i:2/3:p:138-154 Template-Type: ReDIF-Article 1.0 Author-Name: Thabo Falayi Author-X-Name-First: Thabo Author-X-Name-Last: Falayi Author-Name: Freeman Ntuli Author-X-Name-First: Freeman Author-X-Name-Last: Ntuli Author-Name: Felix Ndubisi Okonta Author-X-Name-First: Felix Ndubisi Author-X-Name-Last: Okonta Title: Desilication of calcined pulverised fly ash and use of silicate solution to prepare a mesoporous silica adsorbent for heavy metals in acid mine drainage Abstract: Mesoporous silica (MCM41) adsorbent was prepared from silicate solution produced from silica leaching of calcined pulverised fly ash. MCM41 was used for the removal of heavy metals and neutralisation of acid mine drainage. Silica leaching was optimised using two level full factorial and 13 run central composite rotable uniform design with five centre points. A pH of 7 produced the most pure MCM41 with an external surface area of 98,000 m<SUP align="right"><SMALL>2</SMALL></SUP>m<SUP align="right"><SMALL>-3</SMALL></SUP>. A 4% m/v solid loading of MCM41 could remove 95.5%, 97.3% and 99.6% of Ni, Cu and Fe respectively. The adsorption process was found to fit the Langmuir isotherm and pseudo second order kinetics. The Gibbs free energy of adsorption for all metals was below-20 kJ/mol for all metals. The enthalpy for Fe, Cu and Ni removal were 19.97 kJ/mol, 21.40 kJ/mol and 16.44 kJ/mol respectively and thus endothermic. The significance of the research was that silica could be leached from calcined pulverised fly ash and MCM41 can be used as an adsorbent for heavy metals in acid mine drainage treatment. Journal: Int. J. of Environmental Technology and Management Pages: 155-176 Issue: 2/3 Volume: 22 Year: 2019 Keywords: pulverised fly ash; PFA; MCM41; leaching; central composite rotable uniform design; adsorption; Langmuir isotherm; pseudo second order kinetics; full factorial design; acid mine drainage; metal loading. File-URL: http://www.inderscience.com/link.php?id=102202 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijetma:v:22:y:2019:i:2/3:p:155-176 Template-Type: ReDIF-Article 1.0 Author-Name: Aliye Atay Author-X-Name-First: Aliye Author-X-Name-Last: Atay Author-Name: Yılmaz Akdi Author-X-Name-First: Yılmaz Author-X-Name-Last: Akdi Author-Name: Yasin Okkaoğlu Author-X-Name-First: Yasin Author-X-Name-Last: Okkaoğlu Author-Name: Faruk Çelikkanat Author-X-Name-First: Faruk Author-X-Name-Last: Çelikkanat Title: Forecasting air pollution rates in industrial centres: a case study for Kocaeli-Turkey Abstract: Around the world, air pollution is a leading social problem despite all the precautions. Of all the reasons for this, human-induced ones are at the top of the list. These can be prevented or at least reduced by some measures. Thus, forecasting air pollution is an important issue for all related agencies. In this paper, in order to forecast future values of air pollution rates, two different model approaches were considered. The first one is the Box-Jenkins time series model and the second one is a trigonometric <i>Y</i><SUB align="right"><SMALL><i>t</i></SMALL></SUB> = <i>μ</i> + <i>A</i>cos(<i>w</i><SUB align="right"><SMALL><i>k</i></SMALL></SUB><i>t</i>) + <i>B</i>sin(<i>w</i><SUB align="right"><SMALL><i>k</i></SMALL></SUB><i>t</i>) + <i>e</i><SUB align="right"><SMALL><i>t</i></SMALL></SUB> time series model. As a main air pollution measurement index, monthly average amounts of particulate matter, PM<SUB align="right"><SMALL>10</SMALL></SUB> were used. Kocaeli was selected as a representative city because it is the most important industrial city in Turkey. Hence, data were collected monthly from different air monitoring stations in the city of Kocaeli between 2007 and 2018 and averaged to produce a single time series. Both models yielded high forecast values of PM<SUB align="right"><SMALL>10</SMALL></SUB>. Journal: Int. J. of Environmental Technology and Management Pages: 177-188 Issue: 2/3 Volume: 22 Year: 2019 Keywords: air pollution; seasonality; stationarity; forecasting; Box-Jenkins time series model; PM10; harmonic regression. File-URL: http://www.inderscience.com/link.php?id=102203 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijetma:v:22:y:2019:i:2/3:p:177-188 Template-Type: ReDIF-Article 1.0 Author-Name: Juan A. Román-Aso Author-X-Name-First: Juan A. Author-X-Name-Last: Román-Aso Author-Name: Jaime Vallés-Giménez Author-X-Name-First: Jaime Author-X-Name-Last: Vallés-Giménez Title: The effect of internationalisation and regulation on environmental efficiency: an empirical analysis of Spanish companies Abstract: The purpose of this paper is to estimate the impact of pollution taxes, the emissions trading system and internationalisation on environmental efficiency. To this end, we first estimate it for 100 industrial plants in Spain over a period of 11 years, 2001-2011, using a stochastic frontier analysis (SFA). The first two factors are included to test whether stronger environmental regulations improve efficiency, in line with the Porter hypothesis. The last is devoted to examine whether multinational companies are more efficient than local ones. Our empirical results reveal that pollution taxes do not produce the expected outcome for the entire sample, but in contrast, the emissions trading system has a significant and positive effect on efficiency. Finally, multinational companies are not more efficient, in contrast with previous studies. Journal: Int. J. of Environmental Technology and Management Pages: 189-206 Issue: 2/3 Volume: 22 Year: 2019 Keywords: efficiency; internationalisation; stochastic Frontier analysis; pollution taxes; emission trading system. File-URL: http://www.inderscience.com/link.php?id=102204 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijetma:v:22:y:2019:i:2/3:p:189-206 Template-Type: ReDIF-Article 1.0 Author-Name: Suryasikha Samal Author-X-Name-First: Suryasikha Author-X-Name-Last: Samal Author-Name: C.S.K. Mishra Author-X-Name-First: C.S.K. Author-X-Name-Last: Mishra Author-Name: Sunanda Sahoo Author-X-Name-First: Sunanda Author-X-Name-Last: Sahoo Title: Evaluating the effects of elevated concentrations of urea, phosphogypsum and paper mill sludge on soil chemical, microbial and exoenzyme dynamics Abstract: Urea, phosphogypsum (PG) and paper mill sludge (PMS) are commonly used to address soil nutrient deficiency. In this study, these chemicals were used at recommended agricultural dose (RAD) along with low and high concentrations to assess their effects on soil chemical and biological quality. Urea was applied at 0.5, 1.0, 1.5 g/kg soil, PG at 50, 100, 150 g/kg soil and PMS at 5, 10, 15 g/kg soil. Significant variation in soil pH, electrical conductivity and organic carbon (OC) were noticed in response to chemical concentration and treatment types. The percent OC reduction was high in PG and PMS treated soils. Percent nitrogen and phosphorous in soil increased with the concentrations of urea and PG. Invariably, lower bacterial and fungal population were observed in treated soils relative to control. Activities of amylase, cellulase, invertase, dehydrogenase and protease were inhibited at high concentration of all test chemicals with minor deviations. The study indicated that bacterial population and exoenzymes could be useful markers to evaluate soil toxicity due to hyper concentrations of urea, PG and PMS in soil. Journal: Int. J. of Environmental Technology and Management Pages: 207-219 Issue: 2/3 Volume: 22 Year: 2019 Keywords: exoenzyme; fungi; paper mill sludge; PMS; phosphogypsum; soil bacteria; urea; contamination. File-URL: http://www.inderscience.com/link.php?id=102205 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijetma:v:22:y:2019:i:2/3:p:207-219