Advances of nanotechnology in agro-environmental studies

With the increase in the world population and the demand for food, new agricultural practices have been developed to improve food production through the use of more effective pesticides and fertilisers. These technologies can lead to an uncontrolled release of undesired substances into the environment, with the potential to contaminate soil and groundwater. Today, nanotechnology represents a promising approach to improve agricultural production and remediate polluted sites. This paper reviews the recent applications of nanotechnologies in agro-environmental studies with particular attention to the fate of nanomaterials once introduced in water and soil, to the advantages of their use and their possible toxicology. Findings show that the use of nanomaterials can improve the quality of the environment and help detect and remediate polluted sites. Only a small number of nanomaterials demonstrated potential toxic effects. These are discussed in detail

Biomedical waste management by using nanophotocatalysts: The need for new options

Biomedical waste management is getting significant consideration among treatment technologies, since insufficient management can cause danger to medicinal service specialists, patients, and their environmental conditions. The improvement of waste administration protocols, plans, and policies are surveyed, despite setting up training programs on legitimate waste administration for all healthcare service staff. Most biomedical waste substances do not degrade in the environment, and may also not be thoroughly removed through treatment processes. Therefore, the long-lasting persistence of biomedical waste can effectively have adverse impact on wildlife and human beings, as well. Hence, photocatalysis is gaining increasing attention for eradication of pollutants and for improving the safety and clearness of the environment due to its great potential as a green and eco-friendly process. In this regard, nanostructured photocatalysts, in contrast to their regular counterparts, exhibit significant attributes such as non-toxicity, low cost and higher absorption efficiency in a wider range of the solar spectrum, making them the best candidate to employ for photodegradation. Due to these unique properties of nanophotocatalysts for biomedical waste management, we aim to critically evaluate various aspects of these materials in the present review and highlight their importance in healthcare service settings

Quantification of the environmental impact of titanium dioxide photocatalytic pavements for air pollution remediation

Photocatalytic concrete pavements are a promising technology for mobile source air pollution remediation, however before widespread application of this technology is realized many unanswered questions remain regarding its overall environmental impact. In response to these questions, the goal of this study was to increase the understanding of the environmental impact of photocatalytic concrete pavement highways. To achieve this goal, the objectives of this study were to (A) construct a model that evaluates the nitrogen oxides (NOx) reduction from photocatalytic pavements, (B) quantify the nitrates released from the photocatalytic degradation of NOx, and (C) identify and characterize pathways for TiO2 nanoparticle exposure. To achieve objective A, a field study was conducted to evaluate the NOx reduction. Results showed evidence of minimal photocatalytic reductions with large variability due to many unknown and known parameters. As a result, this study also investigated the use of laboratory results to better understand the significance of the NOx reduction through the creation of a theoretical mass balance Lavoisier box model. Laboratory results indicated that the nitrogen monoxide (NO) oxidation rate is reaction rate mass transfer controlled following the Langmuir- Hinshelwood (L-H) model. A parametric study was completed to evaluate the L-H constants under different environmental conditions and statistical model was created to describe the NO oxidation rate. Incorporating the resulting NO oxidation rate into a Lavoisier box model the mass transfer mechanisms were compared and objective A was achieved. Objectives B and C of the project deal with evaluating potential unintended consequences resulting from implementation of photocatalytic concretes. To complete objective B, nitrates and TiO2 nanoparticles released to water were quantified. Lastly, TiO2 nanoparticles released to the air during construction activities were quantified and characterized to achieve objective C

Chlorpyrifos Removal for Wastewater Reuse

Approximately 1.2 billion people around the world live in areas of physical water scarcity. This could increase to half of the world’s population by 2030 and could displace 24 to 700 million people unless steps are taken to ensure adequate water supply.1 Water scarcity is an escalating issue within the United States, specifically in Western inland states with arid climates. This scarcity is encouraging communities to investigate tertiary level municipal wastewater treatment, allowing for reuse of wastewater. Unfortunately, wastewater contains numerous contaminants that are not regulated by the Environmental Protection Agency (EPA) under the Safe Drinking Water Act (SDWA). Many of these contaminants are endocrine disrupting compounds (EDCs). According to the European Union Commission, an endocrine disruptor is “an exogenous substance that causes adverse health effects in an intact organism, or its progeny, in consequence to the induced changes in endocrine functions.”2 Many EDCs are not completely removed by standard secondary wastewater treatment methods. With the growing demand for potable water, as well as water for irrigation and agricultural purposes, communities are having to evaluate the potential health risks due to EDCs and other unregulated compounds. The Woo-Pig-Sewage team selected one unregulated contaminant, chlorpyrifos(CLP), to test. CLP is an organophosphate insecticide that is commonly used residentially and commercially. CLP has a long term impact asa cholinesterase inhibitor in humans.3 Using traditional biological methods, CLP, as well as other pesticides, are nearly impossible to remove.4 CLP is on the Fourth Unregulated Contaminant Monitoring Rule list produced by the EPA to provide a basis for future regulation.5 A bench scale unit utilizing ozone treatment (O3), ultraviolet radiation (UV), and granular activated carbon (GAC) was constructed to remove this contaminant from dopednanopure water. Ultimately, the selected technologies will be able to treat secondary wastewater effluent from the wastewater treatment plant (WWTP) in Tucumcari, New Mexico for direct or indirect aquifer reintroduction. Direct aquifer reintroduction would involveinjection of water to the existing aquifer, whileindirect aquifer introduction would consist of introducing treated effluent to an existing canal system. An oxidation process paired with UV and GAC filtration can be utilized to remove EDCs such as CLP and other unregulated contaminants from wastewater. O3is extremely effective at oxidizing bacteria as well as other organic molecules. UV is also a commonly used method to degrade organic compounds and is currently being used at the WWTP in Tucumcari, New Mexico and in Fayetteville, Arkansas. GAC is utilized to remove trace amounts of contaminants from wastewater streams, usually as a final treatment before the water is reintroduced to the environment. The WWTP in Rio Rancho, New Mexicocurrently plans to utilize GAC filtration in this manner. The Woo-Pig-Sewage team performed experiments to determine if the combination of O3, UV, and GAC could reduce CLP to a concentration below the minimum detection limit of 0.001ppm. To test the effectiveness of the bench scale, caffeine was used as an organic tracer. Bench scale results indicate that the proposed system is effective in the removal of caffeine and CLP from doped water samples. Caffeine concentrations were reduced to below the minimum detection limit of 0.05 ppm for samples with initial concentrations ranging from 0.1 ppm to 10 ppm. CLP was reduced to below the minimum detection limit of 0.001ppm from and initial concentration of 0.1 ppm. An industrial scale process was sized based on treating secondary effluent from the WWTP in Tucumcari, NM. The total cost was determined to be an additional $2.31 per 1000 gallons, assuming 0$4.95 per 1000 gallons for the existing treatment paired with the proposed system. While this adds a significant cost to the existing treatment at the WWTP in Tucumcari, plants with larger flow rates would see significantly less of an increase in the total cost per 1000 gallons. This can be seen from the comparison of the 144,000gallonper day (gpd) system with existing UV treatment and the 300,000gpdTucumcari system also utilizing UV treatment. The 144,000gpdsystem was estimated to cost about 60% more per 1000 gallons. However, if the Tucumcari WWTP is awarded a grant to cover 100% of the Fixed Capital Investment (FCI), the proposed system would only increase the cost per 1000 gallons by 38%. If the EPA determines that EDCs such as CLP must be removed from the effluent of WWTPs, a process such as the one proposed by the Woo-Pig-Sewage team will be necessary

Pharmaceutical removal: synergy between biological and chemical processes for wastewater treatment

The occurrence of pharmaceuticals in the environment has become a worldwide environmental concern. After administration and excretion, pharmaceuticals end up in wastewater treatment plants. These plants, typically employing biological treatment, are not designed for their removal. Hence, numerous pharmaceuticals are emitted into the environment. Chemical treatment processes like ozonation can effectively remove pharmaceuticals, however these costly processes have disadvantages such as high energy consumption and by-product formation. On the contrary, biological treatment processes are less effective for pharmaceutical removal, but can complement chemical process by for instance by-product removal. In this dissertation the combination of biological and chemical treatment processes for pharmaceutical removal was therefore studied. We found complementariness between various combinations of biological and chemical processes, resulting in the design of cost-effective combined treatment processes for enhanced pharmaceutical removal from wastewater treatment plant effluents.</p

A review of pharmaceuticals and endocrine-disrupting compounds: sources, effects, removal, and detections

There are growing concerns about the increasing trends of emerging micropollutants in the environment due to their potential negative impacts on natural ecosystems and humans. This has attracted attention from both governmental and non-governmental organisations worldwide. Pharmaceuticals, personal care products, and endocrine disruptors are continuously being released consciously or unconsciously into water sources due to poor regulatory frameworks especially in the developing countries. The effects of these contaminants are poorly known. They are not easily biodegradable and have become an environmental nuisance and public health issue. This has heightened the risk of exposure to their deleterious effects in such countries where the majority of the population are still struggling to have access to good quality drinking water supplies and better sanitation. With the rising fear of short- and long-term impacts of the ever-increasing number of persistent recalcitrant organic compounds accumulating in the environment, their removal is gradually becoming an issue to the water treatment industry. Hence, there is a need to develop functional techniques for the management of water contaminated by these emerging contaminants so as to increase the availability and access to safe and good-quality drinking water. We conducted a narrative review on these emerging micropollutants and examined their various documented sources, effects, as well as recent techniques for their effective removal. This becomes necessary due to the increasing occurrence of these pollutants in the aquatic and terrestrial environment. These levels are expected to further increase in the coming years as a consequence of the ever-increasing population density which undoubtedly characterizes developing economies. Our findings show that the present reported treatment techniques in the literature such as biological oxidation/biodegradation, coagulation/flocculation, ozonation, el ectrodialysis, reverse osmosis, sedimentation, filtration, and activated carbon were not designed for removal of these newly identified contaminants, and as such, the techniques are not sufficient and unable to completely degrade the compounds. We therefore recommended the need for concerted efforts to develop better techniques, especially combined advanced oxidative methods to address the shortcomings of and growing challenge to current practices.Web of Scienc

Kentucky Water Resources Research Institute Annual Technical Report FY 2014

The 2014 Annual Technical Report for Kentucky consolidates reporting requirements for the Section 104(b) base grant award into a single document that includes: 1) a synopsis of each research project that was conducted during the period, 2) citations for related publications, reports, and presentations, 3) a description of information transfer activities, 4) a summary a student support during the reporting period, and 5) notable awards and achievements during the year