Abstract: The water that circulates in contact with fluorinated ores is particularly rich in fluoride. The beneficial and the harmful effects of fluoride consumption are well documented. The dental and skeletal fluorosis is the widespread harmful effects of a long consumption of fluoride. WHO recommended level of fluoride in drinking water is 1.5 mg/L. Different methods have been tested for defluoridation of waters such as coagulation, adsorption, precipitation, ion exchange, reverse osmosis, and electrodialysis. The metal embedded biocarbon sorption method is promising in defluoridation of drinking water. The optimal operating conditions such as effect of contact time, effect of pH and effect of adsorbent dose for fluoride removal from aqueous solution using metal embedded biocarbon technology have been determined on synthetic wastewater. The temperature for the continuous mode of experiments was 27 ± 2°C. The result indicates that maximum removal (98%) of fluoride ion was achieved in 180 minutes. The amount of biocarbon dose is 2.0 g. The present results highlight the use of indigenous medicinal plants for the removal of fluoride in ground water. It is economically feasible option because of its bioavailability and its efficiency.

Abstract: Aeration energy demands for bioprocesses and membrane scouring in membrane bioreactors (MBRs) account for 50% to over 70% of the total operational energy consumption. Energy saving achieved by operating MBRs under low dissolved oxygen (DO) would be an interesting approach to bring MBRs to higher levels of efficiency. This review paper is first carried out to provide a systematic investigation on how to achieve good treatment performance and save energy in terms of lowering DO for MBRs. As a result, small scale MBRs operated under low DO (0.5–0.8 mg/L) can allow the process to work properly. At very low DO (0.2 mg/L), MBRs can still have a good performance, e.g., chemical oxygen demands and total nitrogen (TN) removal efficiencies are higher than 90% and 60%, respectively. However, low DO could lead to poor sludge flocculation resulting in increasing small particles which deteriorate the membrane filterability.

Abstract: The emissions of toxic air pollutants from three power plants and one oil refinery were measured for a period of six months and dispersion of pollutants were calculated by using Air Dispersion Modelling Software (ADMS-4). The plume concentration of carbon monoxide, oxides of nitrogen, sulphur dioxide and particulate matter were calculated over long distances to estimate the incremental contribution of these fossil fuel combustion facilities to ambient air. Overall in four plants, the emissions of sulphur dioxide were most critical and 50% of the total exposure was predicted within 20 km distance and the rest of the exposure was observed up to 70 km distances in radii of each plant. Although the annual average concentration increments from a limited number of sources studied were relatively small, but the long-range transport of pollutants created potentially significant health and environmental impacts.

Abstract: This study investigates the optimal process conditions for activated carbon production from local date palm pits using response surface methodology (RSM). Box Behnken statistical technique was used to design the production process in order to determine the influence of activation temperature (300oC to 700oC), % H3PO4 (30% to 70%) and activation time (1 to 3 hours) on the BET surface area. Second-order model developed via regression analysis to describe the BET surface area response was found to be appropriate in predicting the responses within the experimental region to a considerable extent. Analysis of variance (ANOVA) revealed that the influence of the independent variables on the BET surface area is in the order: activation temperature > % H3PO4 > activation time with only temperature and % H3PO4 possessing moderate interaction. The maximum BET surface area from RSM optimisation was estimated to be 1,337.54.2 m2/g achievable at optimum conditions of 54% H3PO4 and 547oC carbonisation temperature at an activation time of 2.067 hours.

Abstract: This study focused on assessing the spatial and temporal variation of pollutant load at six sites along the Tamla Nala, a natural water channel which drains into the River Damodar. Before the discharge point into the river the values of pH (10.23), total suspended solids (745.25 ± 48.98 mg/l), chloride (1218.51 ± 228.86 mg/l), cyanide (0.876 ± 0.348 mg/l), COD (316.8 ± 34.02 mg/l), oil and grease (14.35 ± 1.37 mg/l), total iron (3.62 ± 0.69 mg/l), lead (0.475 ± 0.092 mg/l) and mercury (0.061 ± 0.01 mg/l) exceeded the discharge norms for inland surface waters applicable in India. Factor analysis was found instrumental in delineating the sources of the pollutants and the nature of pollution at the various sites. Calculation of different pollution indices like contamination index (Cd), heavy metal evaluation index (HEI) and total pollutant enrichment index (TPEI) at different sites showed that their values increased downstream. The values of Cd increased from 0 at Site 1 to 21.27 at Site 6, that of HEI from 0.25 to 12.25 and that of TEF from 1 to 13259.35. Therefore Site 1, was identified as unpolluted, while the sites near heavy industries were classified as highly polluted.

Abstract: Nitrilotriacetic acid modification on sugarcane bagasse was performed to evaluate its potential in the removal of basic blue 3 (BB3) from synthetic solution. To the best our knowledge, this is the first time the present modification was reported. A comparative study in the removal capacities of natural sugarcane bagasse (NSB) and nitrilotriacetic acid modified sugarcane bagasse (NTA-SB) indicated that NTA-SB shows an enhancement in BB3 sorption. The sorption characteristics of BB3 by NTA-SB were studied under various experimental conditions such as pH, contact time, initial concentration, sorption isotherm and agitation rate. The optimum pH for the removal of BB3 was recorded in the range of 5 to 9 and the sorption process correlated well with pseudo-second order kinetic model. Experimental data obtained were fitted into both Langmuir and Freundlich isotherm model and the maximum sorption capacity of NTA-SB calculated based on Langmuir model was 54.35 mg/g.

Abstract: The concept of common environmental infrastructure including common effluent treatment plants (CETPs) became popular in India due to several driving forces. A large number of small and medium enterprises located in industrial agglomerate joined hands in setting up such facilities with financial assistance from government. A study is made on the management of eight CETPs located in different industrial estates in Gujarat (India) manufacturing a wide range of chemicals. Various parameters including management styles of CETP operating agencies, wastewater collection and disposal mechanism, design and operating hydraulic as well as pollution load in terms of BOD and COD, capacity utilisation, operational efficiency, sludge generation, capital as well as operating costs involved, etc., are compared. Such facilities play a vital role in promoting industrial clusters especially for small and medium enterprises in developing countries.

Abstract: Toxicity of raw and biotreated olive mill wastewater (OMW) was tested using three organisms, Daphnia pulex, Thamnocephalus platyurus and zebrafish (Danio rerio). Untreated samples demonstrated LC50 values of 1.27%, 0.96% and 0.48% v/v against the aforementioned organisms respectively. After treatment withthe white rot fungi Pleurotus ostreatus, 50% and 56% reduction in toxicity values were observed for Thamnocephalus platyurus and zebrafish respectively, but samples were categorised as ‘very toxic’. A significant reduction in phenols (53%), lignin (74%) and tannin (73%) as well as a differentiation in the impact of the physicochemical parameters on toxicity between the two groups of samples was detected. Toxicity values of untreated samples against the first two aforementioned tests were highly related to phenols and tannins, whereas of treated samples, only to ammonium and phenols. According to the present study, OMW treatment with Pleurotus ostreatus, despite the significant reduction in the toxic contents, does not produce effluents environmentally acceptable for safe disposal.

Abstract: The groundwater chemical quality changes adjacent to solid waste disposal area of Tiruchirappalli metropolitan area was evaluated by groundwater samples collected from three bore wells in the vicinity (December 2006 to November 2007) for one year. The present study area is the place where the Tiruchirappalli solid wastes are land filled. Continuous dumping of solid wastes has rapidly changed the land use pattern, which affects the groundwater quality of the adjacent region. This study has investigated the chemical characteristics and the contamination of groundwater in relation to land use. Most of the water samples were not conforming to the standards for the drinking water quality. The groundwater near the landfill site of Tiruchirappalli City was found to be not suitable either for domestic or irrigation purposes. The groundwater of the study area was found to be affected by temporary as well as permanent hardness. The results of factor analysis indicates that the levels of Ca2+, Mg2+, Cl- and SO42- ions maybe due to pollution from solid waste sources and natural weathering reactions. This paper clearly shows the effect of landfill on groundwater quality and emphasises the necessary precautionary steps to control during the extension of landfill site in the adjacent areas.

Abstract: Biosorption of copper, chromium, lead and cadmium in an up-flow packed-bed bioreactor with biosorbents [sanitary sewage sludge (SS), powdered coconut shell (PCS)] was conducted in a search for solutions to the environmental problem caused by heavy metals. Analysis of the results, demonstrated that the adsorbent had an extraordinary capacity for biosorption of the heavy metals, with a removal percentage of over 90% almost for all metals. The mechanism of the process was evaluated by FT-IR analysis and the functional groups employed in the process were determined. The presence of RNO2 peak at 1,421 cm–1 for unloaded sanitary SS and the presence of C-H group of aromatic ring for unloaded PCS play a major role in adsorption process. In regeneration experiments, increase in sorption performance was observed during cycles of sorption-desorption indicates a maximum adsorption during the onset of the process. Kinetic models (Adams-Bohart model, Yoon and Nelson equation and Thomas model) analysed for the continuous packed-bed biosorption systems are used to determine the biosorption capacity, breakthrough curve of biosorbent and to design of treatment processes.

Abstract: Plants encounter a plethora of conditions in the soil that are either deleterious, neutral, or beneficial to plant growth. Endophyic fungi living in plant organs have a symbiotic relationship with their hosts. In the past, many studies focused on the interactions between plants and endophytic fungi. However, in natural environment, the interactions among plant, endophytic fungi and soil are more comprehensive. Although the main living places for endophytic fungi were host tissues, they closely associated with rhizospheric soil. In this review, the effects of endophytic fungi on soil chemical, microbial and physical environment has been evaluated to provide useful information of improving soil environment by fungal physical function during the mycelia growth and biochemical function in the course of fungal metabolism.

Abstract: The objective is to study the effect of certain parameters on the degradation rate of the dye CI acid blue 113 by cavitation processes. Kinetic models have been developed and validated for ultrasonic and hydrodynamic cavitation treatment with hydrogen peroxide to enhance oxidation. The magnitude of effect of the reaction parameters in acoustic cavitation for geometric ratio, pH, ultrasonic density, initial dye concentration and hydrogen peroxide concentration were –0.4370, –1.2455, 0.1140, –0.3741 and 0.2788. In the case of hydrodynamic cavitation, values for initial dye concentration, pH, inlet pressure, power density and hydrogen peroxide concentration were –0.2562, –0.1494, 0.4556, 0.4807 and 0.1681. Finally, the energy efficiencies of the two processes have been compared. Hydrodynamic cavitation was found to be energy efficient than acoustic cavitation.

Abstract: Phosphorus is noted as the limiting factor of eutrophication. We investigated the impact of different agricultural land use (mixed cropping, horticultural garden and fallow land) on the phosphorus loading of a reservoir. Soil samples were analysed for pH, particle size distribution, organic matter, available P and erodibility index calculated. Water samples analysed for biological oxygen demand (BOD5), dissolved oxygen, phosphate, organic matter and pH. The result shows available phosphorus in the order: fallow land > mixed cropping> horticultural garden. The results suggest that the PO43– in the reservoir maybe due to the effect of the cultivated land around the reservoir. The soil organic matter and available P shows significant patterns of seasonal and profile variations. To prevent runoff from agricultural land to the reservoir, the idea of zero cropping should be encouraged.

Abstract: The research reported here developed a management model for construction and demolition waste in a Brazilian municipality with material flow sheet and economical balances. This waste is produced at a rate of 1.7 kg per person per day. The private construction sector is called upon to run and fund the waste movement network through correct fee structures. The heart of the network is a sorting and treatment facility that receives pre-sorted waste from construction sites and routes all sorted components to their correct destinations, mainly grinded concrete material for further use in construction and recyclable material for reverse logistics.

Abstract: El Salam Canal project aims increasing the Egyptian agricultural productivity through agricultural development by irrigating about 260,400 hectare gross of new lands. In order to stretch the limited water supply to cover these new reclaimed areas, fresh water of River Nile is augmented with agriculture drainage water from Hadous and Lower Serw drains. The current proposed mixing ratio is 1:1 of drainage and freshwater, and this ratio makes a quantity of water of about 4.50 milliard m3/year. Five mixing scenarios are discussed and evaluated for calculating the most suitable quantity of freshwater for mixing with drainage water with a salinity of 950 mg/l and was to be 1,750 million m3/year.

Abstract: Two urban street canyon models, STREET and OSPM, were investigated at Pearse Street, in the centre of Dublin City. Both STREET and OSPM is semi-empirical model that calculates series of hourly concentrations at different receptor locations within a street canyon. From the assessment carried out, for the STREET model, the value of the site specific constant parameter K with a value of 7 gave the best results for STREET modelling. For different consideration of background concentrations best results were obtained using OSPM with HEF with hourly backgrounds followed closely for backgrounds based on stability class for the entire duration of the study period.

Abstract: This paper describes the degradation of commercially available methyl parathion by electro oxidation using Ti/RuO2 as anode, stainless steel as cathode and sodium chloride as a supporting electrolyte. Experiments were carried out at constant flow rate and various current densities such as 10, 12 and15 A/dm2 and various concentrations of sodium chloride. At regular time intervals, reduction of chemical oxygen demand (COD) has been investigated. From the results, addition of 14 g/l g of sodium chloride and applied current density of 15 A/dm2 give better degradation performance than the other. In addition to that degradation of methyl parathion was carried out at different pH ranges such as 4, 7 and 10 at standardised current density of 15 A/dm2. Results indicate that degradation of methyl parathion was more effective when the pH of the solution was at 4. The degradation of methyl parathion has been analysed by high performance liquid chromatography (HPLC), NMR, UV-Vis spectra, FT-IR and TOC.

Abstract: The objective of this study was to estimate and analyse the growth parameters of indigenous monoculture of Pseudomonas aeruginosa and Pseudomonas fluorescence on phenol in an aerobic chemostat culture. The biodegradation data were checked for consistency using carbon and available electron balances and growth parameters were estimated using two forms of growth models: reparameterised Pirt’s model based on Monod approach and a modified model based on substrate consumption rate. The results showed that the biodegradation data were consistent; growth parameter estimates using the two forms of models were similar and that phenol could be oxidatively metabolised with a maximum of about 35.4%–36% and 31%–33% of the energy contained in it incorporated into the P. aeruginosa and P. fluorescence biomass, respectively. The balance (63%–64.6%) for P. aeruginosa, and (67%–69%) for P. fluorescence, is evolved as heat with little energy needed for the maintenance of the respective organisms.

Abstract: Measurements of the two criteria air pollutants sulphur dioxide (SO2) and nitrogen-dioxide (NO2) capable of adversely affecting areas of rich biodiversity were made at a far off coastal remote area Kaikhali (22.022°N and 88.614°E) in one of the world’s largest mangrove ecosystems – ‘The Sundarbans’ from 2004–2007. The objectives of the measurements were to determine the trend in occurrence of these two in the winter period and also to determine their probable sources. The average ranges of SO2 and NO2 concentrations during the winter months over these three years have been found to be (0.34–3.02) ppb and (2.75–21.71) ppb respectively. As, during the study period, no standards for these pollutants were available for such an ecologically sensitive area, their average concentrations for the last year of study have been compared with that for the nearest metropolis Kolkata which indeed confirmed relatively high values of SO2 and NO2 at Kaikhali.

Abstract: The relative performance of a general finite line source model (GFLSM) is assessed using measured NOx concentrationsobtained adjacent to an urban motorway using CEF and HEF. The predicted concentrations are compared with monitored concentrations obtained over a continuous sampling period of one year. Statistical and graphical analyses of the monitored and modelled data are employed to evaluate model performance. It is observed that the values predicted by the GFLSM generally agree well with the monitored data. The effect of background concentrations on model performance is studied and anovel way of defining background concentrations leading to improved model performance of the model is suggested.

Abstract: Coagulation experiments were done using raw water samples from two treatment plants (herein referred to LMTP and LNTP) in Mauritius in jar tests using Moringa oleifera (MO) extract and Sudfloc. Both coagulant aids reduced alum consumption. Sudfloc was required in low concentration as compared to crude extracts of MO. On samples from LMTP, salt extract of MO (MOSE) was six times more efficient than water extracts of MO (MOWE) with 10 mg/L alum (coagulation efficiency of 50%). Samples from LNTP required lower amounts of coagulant aid. MO extracts increased the organic load but gave better removal of aluminium.

Abstract: An experimental method is developed for setting pragmatic short-term landfill diversion targets of municipal waste in emerging economies. Domestic waste composition is shown to be quite uniform throughout developing countries of Africa, Asia and America. Consequently, the method developed in Brazil is readily exportable to other continents with minor numerical adjustments. It consists of determining the threshold fraction of source-separated waste that private recyclers are able to absorb, and is shown to stand at 67% in Brazil. For construction and demolition debris the target in Brazil is identified through waste analysis to be 90%, which corresponds to the amount of reusable material present in the debris. The method is expected to eliminate the guesswork upon setting diversion targets in municipalities throughout the developing world.

Abstract: Biofiltration, a simple technique involving microorganisms supported on a solid matrix, offers an attractive solution for the removal of volatile organic compounds (VOCs). The removal of benzene, toluene and xylene (model VOCs) in vapour phase has been compared individually in the present study using three biofilters. These biofilters were operated at different flow rates and concentrations (<2.7g m–3), to achieve different loading rates of these pollutants. Removal efficiencies greater than 80% for toluene and between 70–82% for benzene and xylene, respectively, were obtained. The maximum VOC elimination capacity in the biofilter ranged between 52–107g m–3 h–1 for benzene, toluene or xylene under the tested condition. High removal efficiencies over the entire range of operating conditions proved the effectiveness and reliability of the biofilter for industrial applications.

Abstract: This paper presents analysis and interpretation of 1-hr average fine (PM1 and PM2.5) and coarse (PM10) particulate matter (PM) concentrations measured during winter 2008 and 2009 at a roadside in Chennai city, India. Results showed typical weekly and diurnal cycles with high concentrations corresponding morning and evening peak traffic flows. The 24-hr average PM10 and PM2.5 concentrations were found to be 135 ± 65 and 73 ± 39 μg/m3 in winter 2008 and 131 ± 75 and 67 ± 32 μg/m3 in winter 2009, respectively and were violating the NAAQS (PM10 = 100 μg/m3; PM2.5 = 60 μg/m3) and WHO (PM10 = 50 μg/m3; PM2.5 = 25 μg/m3) limits. The daily PM1 concentrations at the study site were in the range of 11–200 (mean = 56) μg/m3. The estimated mortality relative risks associated with daily PM concentrations showed a high (81–85%) and moderate (42–48%) relative risks for PM10 and PM2.5, respectively, at the study site.