A study on the phytotoxicity of nano mullite and metal-amended nano mullite on mung bean plants

The presence of engineered nanoparticles is continuously increasing in our environment and causing potential risks to the ecosystem. Researchers from various fields report many articles on the effects of different nanoparticles on plants, animals and microorganisms. Here we have studied for the first time the effect of nano mullite (NMu) and their metal- amended derivatives on the growth of mung bean plants. Results shows that the metal- amended NMu exerts adverse effects on the growth and biomass production of plants compared to NMu. For toxicity studies, we measured the germination index and relative root elongation, while leakage of electrolytes and root oxidizability were measured to study the effect of NMu on mung bean seeds and seedling tissues. Translocation and accumulation of NMu within different parts of the plant body were proved by elemental analysis of dried plant samples.     

Hotel water consumption at a seasonal mass tourist destination. The case of the island of Mallorca

While it is true that tourism is one of the main driving forces behind economic growth in several world regions, it is also true that tourism can have serious negative environmental impacts, especially with regard to water resources. The tourist water demand can generate big problems of sustainability, mainly in those regions where water is scarce, as occurs in most coastal and small island destinations where a large part of world tourism is concentrated. Given the shortage of literature on the subject, further research into the tourist water demand is required, with particular attention to the hotel sector, since hotels are the most popular option for tourists, displaying higher levels of water consumption. The main purpose of this study is to develop a model to analyse hotel water consumption at a mature sun and sand destination with a strong seasonal pattern and scarcity of water; characteristics shared by some of the world's main tourist destinations. Our model includes a set of different hotel variables associated with physical, seasonal and management-related factors and it improves on the capacity to explain water consumption at such destinations. Following a hierarchical regression methodology, the model is empirically tested through a survey distributed to managers of a representative sample of hotels on the island of Mallorca. From the obtained results, interesting recommendations can be made for both hotel managers and policy makers. Among these, it should be highlighted that the strategic move contemplated by many mature destinations towards a higher quality, low-season model could have significant negative effects in terms of the sustainability of water resources. Our results also conclude that managerial decisions, like the system of accommodation that is offered (i.e. the proliferation of the "all-inclusive" formula, both at mature and new destinations), could give rise to the same negative effect. Development of water saving initiatives (usually introduced in response to demand-based factors), also reveals significant effects over water consumption. Finally, other key factor in explaining hotel water consumption is the management system under which the hotel is run.     

The theory of neighbourhood decline due to pariah land uses: Regaining control of the downward cycle

Abstract

Some neighbourhood environments have become dumping grounds for locally unwanted land uses (LULUs) that middle-class Americans do not want near their homes. LULUs may combine with other pariah land uses to collectively undermine the quality of the local environment, reduce investment, government services, the proportion of middle-income people and associated businesses. As important neighbourhood attributes are lost, illegal activities, derelict structures, trash-strewn lots and the concentration of poor and unhealthy people may increase. This paper describes the theory behind the impact of pariah land uses through examples of the downward spiral experienced by Camden, New Jersey and the south Bronx, New York. It then documents the experience of one community, Elizabethport, New Jersey, in reversing that downward spiral. Success in Elizabethport came from the synergistic activities of local, state and federal governments, community groups, and not-for-profit organizations as they struggled to regain control through local environmental management, rebuilding, and reducing crime. Social capital was also strengthened by using a local community health concern—that of childhood asthma. Efforts to reverse the downward spiral of urban decay from pariah land uses should be multi-faceted, spurred by local efforts that address local concerns.     

Impacts of swine manure pits on groundwater quality

Manure deep-pits are commonly used to store manure at confined animal feeding operations. However, previous to this study little information had been collected on the impacts of deep-pits on groundwater quality to provide science-based guidance in formulating regulations and waste management strategies that address risks to human health and the environment. Groundwater quality has been monitored since January 1999 at two hog finishing facilities in Illinois that use deep-pit systems for manure storage. Groundwater samples were collected on a monthly basis and analyzed for inorganic and bacteriological constituent concentrations. The two sites are located in areas with geologic environments representing different vulnerabilities for local groundwater contamination. One site is underlain by more than 6 m of clayey silt, and 7-36 m of shale. Concentrations of chloride, ammonium, phosphate, and potassium indicated that local groundwater quality had not been significantly impacted by pit leakage from this facility. Nitrate concentrations were elevated near the pit, often exceeding the 10 mg N/l drinking water standard. Isotopic nitrate signatures suggested that the nitrate was likely derived from soil organic matter and fertilizer applied to adjacent crop fields. At the other site, sandstone is located 4.6-6.1 m below land surface. Chloride concentrations and delta15N and delta15O values of dissolved nitrate indicated that this facility may have limited and localized impacts on groundwater. Other constituents, including ammonia, potassium, phosphate, and sodium were generally at or less than background concentrations. Trace- and heavy-metal concentrations in groundwater samples collected from both facilities were at concentrations less than drinking water standards. The concentration of inorganic constituents in the groundwater would not likely impact human health. Fecal streptococcus bacteria were detected at least once in groundwater from all monitoring wells at both sites. Fecal streptococcus was more common and at greater concentrations than fecal coliform. The microbiological data suggest that filtration of bacteria by soils may not be as effective as commonly assumed. The presence of fecal bacteria in the shallow groundwater may pose a significant threat to human health if the ground water is used for drinking. Both facilities are less than 4 years old and the short-term impacts of these manure storage facilities on groundwater quality have been limited. Continued monitoring of these facilities will determine if they have a long-term impact on groundwater resources.     

Pollution abatement in the indian pulp and paper industry

Summary In this paper, pollutants in air, water and as solids which stem from the paper industry are discussed, and pollution abatement measures are suggested. The Pulp and Paper Industry is highly capital, material and energy intensive and return on investment is very low. This paper reviews some emerging international principles which are effective in reducing both effluent treatment costs per tonne of paper and the mill discharges, to levels where their environmental impacts become far less significant than at present.Mr Avijit Dey is a graduate in Chemical Engineering from Jadavpur University and at present is Design Engineer in the Paper and Process Cell of Development Consultants Ltd, 24-B Park Street, Calcutta 70016, India. Dr B. Sen Gupta is Reader in the Chemical Engineering Department of Jadavpur University, Calcutta. He obtained his BChE and PhD in Chemical Engineering from Jadavpur University and an ME in Chemical Engineering from the Indian Institute of Science, Bangalore. His research interests involve pulp and paper technology, water conservation and management, and pollution control.     

Groundwater-dependent irrigation costs and benefits for adaptation to global change

The effects of a 1.5 °C global change on irrigation costs and carbon emissions in a groundwater-dependent irrigation system were assessed in the northwestern region of Bangladesh and examined at the global scale to determine possible global impacts and propose necessary adaptation measures. Downscaled climate projections were obtained from an ensemble of eight general circulation models (GCMs) for three representative concentration pathways (RCPs), RCP2.6, RCP4.5, and RCP8.5 and were used to generate the 1.5 °C warming scenarios. A water balance model was used to estimate irrigation demand, a support vector machine (SVM) model was used to simulate groundwater levels, an energy-use model was used to estimate carbon emissions from the irrigation pump, and a multiple linear regression (MLR) model was used to simulate the irrigation costs. The results showed that groundwater levels would likely drop by only 0.03 to 0.4 m under a 1.5 °C temperature increase, which would result in an increase in irrigation costs and carbon emissions ranging from 11.14 to 148.4 Bangladesh taka (BDT) and 0.3 to 4% CO₂ emissions/ha, respectively, in northwestern Bangladesh. The results indicate that the impacts of climate change on irrigation costs for groundwater-dependent irrigation would be negligible if warming is limited to 1.5 °C; however, increased emissions, up to 4%, from irrigation pumps can have a significant impact on the total emissions from agriculture. This study revealed that similar impacts from irrigation pumps worldwide would result in an increase in carbon emissions by 4.65 to 65.06 thousand tons, based only on emissions from groundwater-dependent rice fields. Restricting groundwater-based irrigation in regions where the groundwater is already vulnerable, improving irrigation efficiency by educating farmers and enhancing pump efficiency by following optimum pumping guidelines can mitigate the impacts of climate change on groundwater resources, increase farmers’ profits, and reduce carbon emissions in regions with groundwater-dependent irrigation.     

Phytoremediation and sequestration of soil metals using the CRISPR/Cas9 technology to modify plants: a review

Environmental Chemistry Letters - Soil contamination by toxic metals is a major health issue that could be partly solved by using genetically-modified plants. For that, the recently developed...     

A mathematical model to investigate the impact of overgrowing population-induced mining on forest resources

Here, we develop a mathematical model which investigates the impact of growing population and rampant mining on forest resources, present in an urban region. In order to demonstrate the effect imposed by the overgrowing population on the environment, population pressure is incorporated in the model, which augments mining activities in the given region. The obtained model is studied qualitatively using stability theory of differential equations, while it is quantitatively analyzed through numerical simulation. The results of the model reveal that a whopping increase in unchecked mining activities, induced through excessive population growth, leads to declination of forest resources in a region. Therefore, sustainable mining is suggested through control measures imposed by the government on mining activities.     

Performance study and kinetic modeling of hybrid bioreactor for treatment of bi-substrate mixture of phenol-m-cresol in wastewater: Process optimization with response surface methodology

Performance of a hybrid reactor comprising of trickling filter(TF) and aeration tank(AT) unit was studied for biological treatment of wastewater containing mixture of phenol and m-cresol,using mixed microbial culture.The reactor was operated with hydraulic loading rates(HLR) and phenolics loading rates(PLR) between 0.222-1.078m3/(m2·day) and 0.900-3.456kg/(m3·day),respectively.The efficiency of substrate removal varied between 71%-100% for the range of HLR and PLR studied.The fixed film unit showed better substrate removal efficiency than the aeration tank and was more resistant to substrate inhibition.The kinetic parameters related to both units of the reactor were evaluated and their variation with HLR and PLR were monitored.It revealed the presence of substrate inhibition at high PLR both in TF and AT unit.The biofilm model established the substrate concentration profile within the film by solving differential equation of substrate mass transfer using boundary problem solver tool ’bvp4c’ of MATLAB 7.1 software.Response surface methodology was used to design and optimize the biodegradation process using Design Expert 8 software,where phenol and m-cresol concentrations,residence time were chosen as input variables and percentage of removal was the response.The design of experiment showed that a quadratic model could be fitted best for the present experimental study.Significant interaction of the residence time with the substrate concentrations was observed.The optimized condition for operating the reactor as predicted by the model was 230mg/L of phenol,190mg/L of m-cresol with residence time of 24.82 hr to achieve 99.92% substrate removal.