Showing papers in "Reviews in Environmental Science and Bio\/technology in 2012"

Anaerobic co-digestion of organic wastes

Abstract: Over the last years anaerobic digestion has been successfully established as technology to treat organic wastes. The perspective of turning, through a low-cost process, organic wastes into biogas, a source of renewable energy and profit, has certainly increased the interest around this technology and has required several studies aimed to develop methods that could improve the performance as well as the efficiency of this process. The present work reviews the most interesting results achieved through such studies, mainly focusing on the following three aspects: (1) the analysis of the organic substrates typically co-digested to exploit their complementary characteristics; (2) the need of pre-treating the substrates before their digestion in order to change their physical and/or chemical characteristics; (3) the usefulness of mathematical models simulating the anaerobic co-digestion process. In particular these studies have demonstrated that combining different organic wastes results in a substrate better balanced and assorted in terms of nutrients, pre-treatments make organic solids more accessible and degradable to microorganisms, whereas mathematical models are extremely useful to predict the co-digestion process performance and therefore can be successfully used to choose the best substrates to mix as well as the most suitable pre-treatments to be applied.

Antioxidant enzyme responses of plants to heavy metal stress

Abstract: Heavy metal pollutions caused by natural processes or anthropological activities such as metal industries, mining, mineral fertilizers, pesticides and others pose serious environmental problems in present days. Evidently there is an urgent need of efficient remediation techniques that can tackle problems of such extent, especially in polluted soil and water resources. Phytoremediation is one such approach that devices effective and affordable ways of engaging suitable plants to cleanse the nature. Excessive accumulation of metal in plant tissues are known to cause oxidative stress. These, in turn differentially affect other plant processes that lead to loss of cellular homeostasis resulting in adverse affects on their growth and development apart from others. Plants have limited mechanisms of stress avoidance and require flexible means of adaptation to changing. A common feature to combat stress factors is synchronized function of antioxidant enzymes that helps alleviating cellular damage by limiting reactive oxygen species (ROS). Although, ROS are inevitable byproducts from essential aerobic metabolisms, these are needed under sub-lethal levels for normal plant growth. Understanding the interplay between oxidative stress in plants and role of antioxidant enzymes can result in developing plants that can overcome oxidative stress with the expression of antioxidant enzymes. These mechanisms have been proving to have immense potential for remediating these metals through the process of phytoremediation. The aim of this review is to assemble our current understandings of role of antioxidant enzymes of plants subjected to heavy metal stress.

Threats, management and envisaged utilizations of aquatic weed Eichhornia crassipes: an overview

Abstract: Eichhornia crassipes or water hyacinth is a free-floating plant, growing plentifully in the tropical water bodies. This invasive weed poses multiple hazards ranging from ecological and economical to social. It tends to endanger biodiversity, cause eutrophication, shelter pests, clog fresh waterways, affect agriculture and aquaculture, hamper shipping and recreational activities. Existing control methods have been insufficient to contain its aggressive propagation. Recently, it has been envisaged that successful utilization of this weed can solve the associated problems associated with them. It is being speculated that the huge biomass can be used in waste water treatment, heavy metal and dye remediation, as substrate for bioethanol and biogas production, electricity generation, industrial uses, human food and antioxidants, medicines, feed, agriculture and sustainable development. Towards this quest many approaches have been undertaken and partial success is achieved. If harnessed properly, this weed-based green technology can solve many of the issues our society faces now. In this context, the papers published in recent years have been reviewed, with the objective of creating public awareness and bolstering management and utilization of this cumbersome invasive weed.

Potential of plant as a biological factory to synthesize gold and silver nanoparticles and their applications

Abstract: Green synthesis of metallic nanoparticles has become a promising field of research in recent years. Syntheses of gold and silver nanoparticles by various chemical and physical methods as well as the biosynthetic approach mediated by numerous microorganisms have been actively researched. A more scalable and economic route to produce these metallic nanoparticles would be through the plant-mediated synthetic approach. Owing to the biodiversity of plant biomasses, the mechanism by which bioconstituents of plants have contributed to the synthetic process is yet to be fully understood. Nevertheless, the feasibility of controlling the shape and size of nanoparticles by varying the reaction conditions has been demonstrated in many studies. This paper provides an overview of the plant-mediated syntheses of gold and silver nanoparticles, possible compounds and mechanisms that might be responsible for the bioreduction process as well as the potential applications of biosynthesized nanoparticles in different fields. The challenges and limitations of this plant-mediated biosynthetic approach are also discussed.

Recent advances in the development of biosensor for phenol: a review

Abstract: Phenol and its derivatives are widespread contaminants whose sources are both natural and industrial. Phenol is massively produced and used as a starting material for synthetic polymers and fibers. Although phenolic compounds play important biochemical and physiological roles in living systems, their accumulation in the environment as a result of intensive human activity may result in drastic ecological problem. Various analytical techniques are available for the detection of phenol in environmental samples. But they need complex sample pre-treatment so as are time consuming, costly and use heavy devices. On the other hand a biosensor is a device that gives rapid detection, cost effective and easy. A review study was carried out to accumulate the possible biosensors for the detection of phenolic compounds in environmental samples. A number of biological components including microorganisms, enzymes, antibodies, antigens, nucleic acids etc. can be used for the construction of biosensors that was found to detect phenolic compounds. Of all type of biological components microorganisms and enzymes are mostly used. The microorganisms are Pseudomonas, Moraxella, Arthrobacter, Rhodococcus, and Trichosporon. The most used enzymes are tyrosinase, peroxidase, laccase, glucose dehydrogenase, cellobiose dehydrogenase etc. Antibody sensors can detect a very trace level. The biorecognition of DNA biosensors occur by hybridization of DNA. Biosensors are found to work well when the biological sensing element is immobilized. A variety of immobilization techniques were found to use as adsorption, covalent binding, entrapment, cross-linking etc. For immobilization the matrices used was polyvinyl alcohol, Osmium complex, nafion/sol–gel silicate, chitosan, silica gel etc.

Fertiliser drawn forward osmosis desalination: the concept, performance and limitations for fertigation

Abstract: With the world’s population growing rapidly, pressure is increasing on the limited fresh water resources Membrane technology could play a vital role in solving the water scarcity issues through alternative sources such as saline water sources and wastewater reclamation The current generation of membrane technologies, particularly reverse osmosis (RO), has significantly improved in performance However, RO desalination is still energy intensive and any effort to improve energy efficiency increases total cost of the product water Since energy, environment and climate change issues are all inter-related, desalination for large-scale irrigation requires new novel technologies that address the energy issues Forward osmosis (FO) is an emerging membrane technology However, FO desalination for potable water is still a challenge because, recovery and regeneration of draw solutes require additional processes and energy This article focuses on the application of FO desalination for non-potable irrigation where maximum water is required In this concept of fertiliser drawn FO (FDFO) desalination, fertilisers are used as draw solutions (DS) The diluted draw solution after desalination can be directly applied for fertigation without the need for recovery and regeneration of DS FDFO desalination can make irrigation water available at comparatively lower energy than the current desalination technologies As a low energy technology, FDFO can be easily powered by renewable energy sources and therefore suitable for inland and remote applications This article outlines the concept of FDFO desalination and critically evaluates the scope and limitations of this technology for fertigation, including suggestions on options to overcome some of these limitations

Fouling in reverse osmosis (RO) membrane in water recovery from secondary effluent: a review

Abstract: Reverse osmosis (RO) is the most preferable process for water recovery from secondary effluent (SE) because of its higher rejection of impurities with lower associated cost and higher quality of product. Fouling still is a major challenge during the water recovery due to higher contaminant loadings in SE and high rejection capability of this membrane. The presence of suspended solids, colloidal and organic matters, and high level of biological activities in SE further elevate fouling potentiality. This review was performed to identify major foulants causing hindrance in sustainable application of reverse osmosis and to present available pre-treatment options for these foulants. There are four fouling types present in RO namely; bio-fouling, inorganic/scaling, organic, and particulate fouling. Among them; bio-fouling is less understood but dominant since the pre-treatment options are not well developed. Other fouling mechanisms have been overcome by well developed pre-treatments. The major foulants for RO are dissolved and macromolecular organic substances, sparingly soluble inorganic compounds, colloidal and suspended particles, and micro-organisms. Some of these potential fouling water quality parameters (PFWQPs) are interrelated with each others such as electrical conductivity is a surrogate measure of total dissolved solids with established stable relationship. Most of these PFWQPs such as total suspended solids, turbidity, chemical oxygen demand can be removed by conventional pre-treatment; some such as colloidal particles and micro-organisms by modern options and even others such as endocrine disrupting compounds, pharmaceutical and personal care products are still challenging for current pre-treatments. These foulants need to be identified properly to integrate appropriate pre-treatments for minimizing fouling potentiality to increase water recovery at minimal costs.

Cation-mediated cross-linking in natural organic matter: a review

Abstract: Interactions between cations and natural organic matter (NOM) are central for the stability of organic matter, formation of supramolecular NOM structure, formation of organo-mineral associations, soil aggregation and binding of organic contaminants. The effect of multivalent cations on environmental functionalities of NOM strongly depends on the relative importance between intramolecular complexation and intermolecular cross-linking, the degree of which will be determined by the spatial arrangement of the hydrophilic functional groups in NOM. This literature review seeks to evaluate the current state of the art regarding the relevance of intermolecular cross-links via bridges of multivalent cations. Cross-linking has been suggested to explain among others aggregate stability, retarded dissolved organic matter release, reduced organic matter (OM) solubility as well as increase in degree and nonlinearity of sorption or organic chemicals to NOM. Although the cross-linking mechanism has been suggested in numerous studies, it has not yet been verified directly. The dynamics of the intermolecular cross-links, their persistence as well as their interplay with OM and their influence on stability and bioavailability of organic chemicals is up to now unknown. The major challenge in this context is the development of a suitable combination of experimental and instrumental techniques and relating the results to molecular and physicochemical models on the basis of targeted combination of spectroscopic, molecular modelling and thermoanalytical methods.

Potential of fruit and vegetable wastes as novel biosorbents: summarizing the recent studies

Abstract: Fruit and vegetable wastes produced in astronomical quantities from food processing and agriculture industries often cause nuisance in municipal landfills owing to their high biodegradability. Biosorption by these waste-based adsorbents can be used as a cost effective and efficient technique for the removal of toxic heavy metals and dyes from wastewater. Recently, many papers claiming the feasible use of these biosorbents for water decontamination, treatment of industrial and agricultural wastewater and valuable metal recovery have been published. The organic waste-based adsorbents, characterized by good uptake capacity and rapid kinetics are expected to be economically and ecologically viable. This paper presents a judicious and pragmatic review depicting the key advances in implications of the fruit and vegetable wastes in pollution mitigation, the underlying mechanisms, major challenges and the future implementations. This compilation is expected to provide an impetus to the bioremediation research and promote green technology.

A review of techniques and technologies for sand and dust storm detection

Abstract: Sand and dust storms (SDSs) are common phenomena in many parts of the world, which offer serious hazards to the environment, economy and health. An early warning of the approaching SDS would allow people to take precautionary measures and help minimize its terrible effects on the daily life. This requires continuous monitoring of the fugitive dust, sandstorms and movements of sandbanks in a certain area. Several technologies for monitoring of the dust and other environmental changes are available, such as lookout-tower, video-surveillance, sensory information, satellite imagery, unmanned aerial vehicle and hybrid approaches. A particular technology is suitable only for detecting the certain types of SDS, but a hybrid approach can detect many types of SDS. In this paper, we provide a quick review of the techniques and technologies for SDS monitoring. We provide an overview of the data requirements, dust modeling and techniques for SDS detection and prediction. We also summarize, classify and compare different technologies for SDS detection and prediction, and propose that a hybrid approach consisting of satellite imagery and wireless sensor networks is best suitable for detecting and predicting SDSs of all types.

Characterization of MBT plants input and outputs: a review

Abstract: Mechanical–biological treatment (MBT) plants treat municipal solid waste (MSW), residual after source separation, with the aim to minimize the environmental impact associated with the residues landfilling and to add values to waste outflows for a potential utilization. MBT consists in a combination of mechanical processes (shredding, size, density and magnetic separation, densification, etc.) and biological treatment (aerobic or anaerobic degradation) of the organic fraction mechanically separated. In this work a review regarding the MBT input and outputs characterization is presented with the aim to evaluate the quality of them and the effectiveness of MBT plants to produce materials that can be utilized for material/energy recovery. A strong variability of the different flows characteristics, mainly due to the heterogeneity of the input MSW and to the different configurations of processing units employed in MBT plants, was highlighted. Therefore most suitable end-uses or disposal for the MBT outputs are site-specific and should be related to prior detailed characterizations of the materials able to identify specific quality classes defined by proper technical standards.

Biofiltration for treating VOCs: an overview

Abstract: In this paper we present a review of Biofiltration, one of the air pollution control technologies (APCT) used to treat volatile organic compounds (VOCs) effectively. It also talks about the history of biofiltration, and also proposes few ideas for the future developments in the biofiltration research pertaining to VOC control. Moreover, the paper also discusses about various important physical, chemical and biological factors which affect the performance of a biofilter both directly and indirectly. This paper will be handier for those who are new to the field of biofiltration research for VOC treatment.

Coral reefs studies and threats in Malaysia: a mini review

Abstract: Coral reefs in Malaysia are about 4,006 km2 with over 550 species contributed to nation’s economy. Coral reefs studies and threats in Malaysia have been reviewed briefly. Perspectives are addressed as coral reefs studies, threats, gaps and future studies. Coral reefs in Malaysia are being damaged at an increasing rate where it faces natural and anthropogenic stresses. Excellent summaries are available in terms of coral reefs cover throughout Malaysia however scarce in terms of qualitative, quantitative and biogeographical data. There are also limited studies on heavy metals concentration in corals skeleton studies. Poor to fair conditions of coral reefs in Peninsular Malaysia is due to increases of sedimentation and tourism impacts. Overfishing and fish blasting were main threats of coral reefs damage in Sabah. In Sarawak, coral reefs are threatened by high sedimentation and sand mining. The 1998–1999 bleaching event also affected coral reefs in Malaysia due to climate change. Gaps in coral reefs studies can be completed by continuous collaborations between local and international researchers as well as research by local universities. Economic valuation, policy analysis and community participation are directions in future coral reefs studies in Malaysia. Future studies are to understand effects of management on coral reefs health and impact of pollution on coral reefs growth with a standard coral reefs methodology. Established legal systems to reduce threats received by coral reefs are also need to be introduced. Role of science-driven management with community participation and media mass are also gaps to be highlighted in future studies.

Evaluation of potential of molecular and physical techniques in studying biodeterioration

Abstract: Recently, researcher’s abilities to elucidate the biogeophysical and biogeochemical mechanisms of complex biodeterioration processes occurring at monumental sites has been greatly revolutionized by use of molecular, physical and highly sophisticated so called high throughput next generation sequencing techniques. Such achievements are obvious in several areas of biotechnology and environmental science including geomicrobiological studies related to biodeterioration and bioconservation of ancient historic architectural monuments and artworks. Application of these techniques in studying architectural monuments and artworks is not just limited to predict the prevalence microbial diversity and identifying the mechanism of biodeterioration caused by inhabiting microorganisms, but also to provide in-depth molecular, biogeophysical and biogeochemical basis of how microorganisms respond to different environmental conditions to accelerate the process of biodeterioration, which in turn will offer tremendous opportunities to environmental scientists and researchers to formulate or device preventive and remedial safeguard techniques to control undesirable growth and survival of microorganisms on monuments and work of arts. Further evaluation studies and investigations are currently in progress to upgrade these molecular and physical strategies and to develop reliable approaches to better explain the various processes of biodeterioration and related phenomenon. A comprehensive description of techniques being successfully incorporated and applied in this regard is described in this review. Taken together, it can be anticipated that these techniques possess an astounding potential to turn around research related to geomicrobiological studies related to biodeterioration and bioconservation of monuments.

Biodiversity as a tool for waste phycoremediation and biomass production

Abstract: Over the past 20 years, plants have been used to anincreasing extent in various environments for mitigat-ing pollutant concentrations in contaminated sites(soils or waters) and for producing biodiesel. How-ever, because plant growth rates and biomass yieldsare low and because a considerable amount of waterand large surface area are required, intensive cultiva-tion of microalgae has been proposed as an alternativemethod for phycoremediation and producing bio-energy (Dismukes et al. 2008; Rawat et al. 2011).However, mass cultivation of microalgae in opensystems (and, to a certain extent, in closed systems) issubject to strong competition (from local microalgalcommunities when single species microalgal biopro-cesses are considered) and predation and are partic-ularly sensitive to sudden changes in environmentalconditions (light, temperature and nutrient availabil-ity). Such factors may contribute to the rapid collapseof the microalgae culture. The use of indigenousmicroalgae species for local intensive production,better adapted to local climatic conditions, may reducepotential competition to some extent without risk ofthe culture becoming noxious or invasive, as claimedrecently by Wilkie et al. (2011). However, the stabilityof microalgal productivity in a single species culture isdoubtful when cultures are supplied with heteroge-neous wastewaters containing various organic andinorganic compounds, some of which are toxic,together with their own microbial communities feed-ing on the waste.The application of ecological observations ofnatural ecosystems to large-scale microalgal cultiva-tion might help to ensure successful, intensive, stablemass algal production by increasing the efficiency ofmultiple resource use and by reducing potentialcompetition and predation.1 Exploiting microalgal diversityRecent studies have shown positive relationshipsbetween microalgae diversity and resource (phospho-rus, nitrate) use efficiency in freshwater and brackishcommunities (Ptacnik et al. 2008; Cardinale 2011).Algal communities with greater species richness makebetter use of niche opportunities in an environment,allowing them to capture a higher proportion ofavailableresources(Cardinale2011).Thegreatvarietyof nutrition modes displayed by microalgae speciesfor acquiring carbon or nutrients helps to extendtheir niche opportunities in changing environments.Depending on the species, their physiology, cell sizeand biotic and abiotic environmental growth condi-tions, microalgae can use various forms of nitro-gen (elemental nitrogen, ammonium, nitrate, organic

Exotic tropical plant Psidium cattleianum : a review on prospects and threats

Abstract: Psidium cattleianum Sabine or strawberry guava is an exotic tropical plant belonging to Myrtaceae family. Generally, this ornamental shrub is prized for its aesthetic value. However, this low-profile plant is an untapped source of therapeutically relevant phytochemicals, evident from the structural investigations. The delicious tart ripe fruits can be eaten fresh, made into a plethora of food products and pectin can be extracted from the pulp. Ameliorative attributes of this shrub viz. antioxidant, antimicrobial and antiproliferative have been reported in recent times. On the other hand, this shrub has emerged as a habitat-altering pest in Hawaii, threatening the rare endemic flora. Releasing biocontrol agents into the wilderness to hinder the unchecked proliferation of this hardy shrub is being speculated and conducted, without any obvious success till now. In this mini review the industrial and pharmaceutical prospect of this little known plant will be discussed. It is believed that, this review will serve as a useful reference and encourage future research on hitherto unknown potential of this exotic plant.

Environmental hazards of arsenic associated with black shales: a review on geochemistry, enrichment and leaching mechanism

Abstract: Black shales are high organic matter-rich dark coloured mudstones those are often deposited during ‘oceanic anoxia events’. Most of the black shale horizons are rich in arsenic far above their average crustal abundance and are susceptible to weathering eventually leaching high As contents to the surrounding environment causing As enrichment in soil and water which adversely affect the living beings. Numerous arsenic contaminations are being reported from black shale hosted areas globally, hence, making extremely crucial to understand the processes of enrichment, leaching and broader prospective of environmental hazards. Few studies have shown arsenic concentrations as high as 6,000 mg/kg within black shales causing groundwater enrichment up to hundreds mg/L. Arsenic is commonly attached to sulphide mineral structure and partly to organic matter and clay contents during deposition and diagenetic processes. Majority of sulphide bound arsenic becomes available to oxidative dissolution processes in presence of atmospheric oxygen and water which is further triggered by certain microbial community such as Acidophilus ferrooxidans hence, enhancing arsenic release. Physical weathering processes carry the arsenic-rich shale constituents to the depositional site where it is dissolved subsequently. Chemical diffusion and mechanical transport are two prime processes transporting arsenic from black shale horizons to the water bodies or soil columns, while air pollutions are caused by combustions of organic matter-rich coaly shales.

Flow and sediment transport in vegetated waterways: a review

Abstract: One of the most important waterway components is vegetation, which play a pivotal role in the flow and sediment transport. Vegetation environment and characteristics, including vegetation porosity or density, shape, flexibility and vegetation height, are significantly affected in vegetated channels. Various vegetation positions and arrangements such as patches significantly affect the sediment deposition rate and flow turbulence. This paper reviews recent works conducted on vegetated open channels, which include the effect of different vegetation arrangements and vegetation characteristics on mass transport and turbulence structure. Studies based on laboratory, field works, and modeling, have been reviewed based on previous methods used by different researchers. Methods used in vegetation porosity evaluation, rate of flow and sediment transport properties are presented. In short, flow and transport depend on the vegetation properties and flow structure conditions.

Evaluating membrane technology for clarification of sugarcane juice

Abstract: The sugar industry needs to find efficient methods in clarifying the raw sugarcane juice in order to improve the quality of the clarified juice and to reduce or eliminate the usage of chemicals (lime). Conventional clarifiers use heavy equipment which lead to high operating costs and associated environmental problems. In sugar mills, ensuring the production of juice of consistently high clarity and low colour through the clarification process is a challenging task. The variations in the incoming juice characteristics due to differences in cane variety, soil and growing conditions, weather patterns and season make this task even more challenging. Membrane filtration promises superior quality juice with better clarity, much lower viscosity and noticeable colour removal. Ultrafiltration of clarified sugarcane juice can be done through spiral wound or flat sheet filtration systems using polymeric membranes or tubular filtration systems using ceramic membranes. This review evaluates the applications of membrane technology in sugar industry all over the world and the need for it in the Australian sugar industry. This is an important first step to identify the appropriate types and applications of membranes.

Reduction of dioxin emissions from thermal waste treatment plants: a brief survey

Abstract: Since 1977 dioxins were detected in fly ashes from waste incineration plants; this class of compounds is of major importance concerning the acceptance of this technology. Extended research and development revealed in short time the main formation mechanism of dioxins, the importance of good combustion control, the influence of halogens and sulphur, and paved the way for strategies for minimisation of formation, and efficient abatement. The main steps in this development as well as the current situation are described.

Ultrafine particle emissions for municipal waste-to-energy plants and residential heating boilers

Abstract: Most recent air quality issues related to particulate matter pollution address ultrafine (UFP < 0.1 μm) and nanoparticle (NP < 0.05 μm) size fractions and their involvement in health related issues. Consequently, large efforts have been dedicated to the evaluation of their concentration levels in ambient air, with particular reference to those situations typically representative of the highest expected human exposures (urban sites with high traffic density, indoor domestic environments, industrial workplaces). Similar investigations for assessing emissions arising from outdoor sources responsible of their origin have been mostly confined to vehicle emissions, particularly light and heavy duty diesel engines, with very limited informations for stationary combustion activities, yet considered of potential significance in the whole emissions budget. Still less attention has been attracted by some specific sources like waste to energy (WTE) plants and small scale residential heating boilers, despite their large utilization in or near heavily populated areas and their interest in public stakeholders for health related concerns. Present paper reports on the available data of UFP and NP emissions from full scale WTE plants and from small scale boilers fired with fuels typical of heat generation in the residential sector (wood pellets, light oil, natural gas), with particular reference on measurements conducted with those sampling techniques proposed recently for investigating also the contribution of the condensable fraction from semivolatile flue gas components on primary UFP concentrations and corresponding size distributions.

Flexible design of urban drainage systems: demand led research for Hamburg-Wilhelmsburg

Abstract: in urban drainage systems With increasing global change pressures (urbanisation, climate change, etc.), cities of the future will experience difficulties in managing their water supply, drainage and wastewater. These global change pressures were addressed by SWITCH, an EU 6th Framework research project that developed technological and socio-economic solutions for the sustainable management of water in the city of the future. The project involved 32 partners from across the globe working directly with stakeholders in 12 demonstration cities. An important component of SWITCH was gathering together stakeholders that were involved with, or interested in, urban water management. These multi-stakeholder learning alliances guided and supported SWITCH on implementing research and demonstration activities, by taking account of local problems and needs (Vairavamoorthy 2009b).

ROUTES: innovative solutions for municipal sludge treatment and management

Abstract: Management of sewage sludge is going to be a big challenge in near future due to rapid urbanization and economic growth, in particular in Europe. The Routes project http://www.eu-routes.org (ref. # 265156) is addressed to discover new routes in wastewater and sludge treatment which allow: (a) to prepare sludge for agricultural utilization by transforming it in a very clean and stabilized product with respect to hygienic aspects and phytotoxicity; (b) to minimize sludge production by new solutions including the use of innovative processes based on metabolic uncoupling or of innovative reactors like microbial fuel cells or sequencing batch biofilter granular reactor; (c) to promote recovery of valuable materials from anaerobic digestion, i.e. biopolymers as polyhydroxyalkanoates and fertilizers; (d) to set up and prove at practical scale a novel technique for sludge disposal (wet oxidation) as sustainable alternative to the nowadays the most used incineration; (e) to minimize energy pumping by adjusting solid concentration, on a practical installation. The general objective of the Routes proposal is therefore to set up a portfolio of different solutions to be applied in different conditions and circumstances, strictly following the waste hierarchy of the EU Directive 08/98 on waste. The above solutions will be studied either in the laboratory or at practical scale, depending on the maturity of the technology, in order to provide the Commission, the technical and scientific community and end-users with applicable solutions and new routes for sludge management.

Treatments of polluted emissions from incinerator gases: a succinct review

Abstract: Due to the incomplete mineralisation of some organic compounds during the incineration of municipal solid waste, gaseous emissions are loaded with a large amount of particulate matter, undesirable elements and toxic molecules. Typically, an incinerator of urban solid waste produces large flows of hot gaseous emissions to be purified before being released into the atmosphere. In this paper, treatments of flue gas from a typical municipal waste incinerator are described. The first step is an energy recovery system through heat exchangers to make steam or hot water. Steam is used to produce electricity via a turbine. The economic balance of the total system is very often dependent on the heat recovery. The second step involves particle removal technologies. Different systems are available such as cyclones, scrubbers, electrostatic precipitators or baghouse filters. The third step is the removal of numerous molecule families such as acid compounds (SOx, HCl, HF), nitrogen oxides (NOx), metal species and many organic compounds. The latter include dioxins, furans and volatile organic compounds. Some treatment processes are described according to the pollutant family.

How to float a wind turbine

Abstract: Far-offshore wind turbines are attractive in view of harnessing high-speed winds and reducing impact on population. When the sea is hundreds of metres deep, drilling wind turbines down to the seabed is too expensive. Today’s bottom-mounted foundations could be replaced by floating platforms, which can minimise the lateral wave-loads acting on the wind turbine and reduce the foundation cost in deep water. Computer models capable of calculating the motion of a full floating wind turbine are at an early stage of development. An efficient strategy to minimise the computational cost is also lacking. This contribution highlights how the motion of a floating wind turbine, and its interaction with the ocean, can be predicted by means of computer-model simulations.

(Re)Greening photochemistry: using light for degrading persistent organic pollutants

Abstract: Light is a cheap and abundant chemical reagent, capable of inducing highly selective reactions, some of which cannot be reasonably carried out by alternative ways nowadays. Photochemical processes may take place directly from the excited states or short-lived intermediates generated after light absorption or, alternatively, through reaction with species indirectly generated by the action of light on other chemicals present in the medium (catalysts or secondary reagents). As a consequence a range of possibilities are open to transform and/or degrade refractory pollutants or undesired chemicals or microbia in air, water, soil, on surfaces, etc., as well as other applications described below.

ULIXES, unravelling and exploiting Mediterranean Sea microbial diversity and ecology for xenobiotics’ and pollutants’ clean up

Abstract: The civilizations in the Mediterranean Sea have deeply changed the local environment, especially with the extraction of subsurface oil and gas, their refinery and transportation. Major environmental impacts are affecting all the sides of the basin with actual and potential natural and socio-economic problems. Events like the recent BP’s oil disaster in the Gulf of Mexico would have a tremendous impact on a close basin like the Mediterranean Sea. The recently EU-funded project ULIXES (http://www.ulixes.unimi.it/) aims to unravel, categorize, catalogue, exploit and manage the microbial diversity available in the Mediterranean Sea for addressing bioremediation of polluted marine sites. The rationale of the project is based on the multiple diverse environmental niches of the Mediterranean Sea and the huge range of microorganisms inhabiting therein. Microbial consortia and their ecology, their components or products are used for designing novel pollutant- and site-tailored bioremediation approaches. ULIXES exploits microbial resource mining by the isolation of novel microorganisms as well as by novel advanced ‘meta-omics’ technologies for solving pollution of three major high priority pollutant classes, petroleum hydrocarbons, chlorinated compounds and heavy metals. A network of twelve European and Southern Mediterranean partners is exploring the microbial diversity and ecology associated to a large set of polluted environmental matrices including seashore sands, lagoons, harbors and deep-sea sediments, oil tanker shipwreck sites, as well as coastal and deep sea natural sites where hydrocarbon seepages occur. The mined collections are exploited for developing novel bioremediation processes to be tested in ex situ and in situ field bioremediation trials.

Asbestiform fibers in the Biancavilla site of national interest (Sicily, Italy): review of environmental data via GIS platforms

Abstract: After the observation of cases of malignant pleural neoplasm in Biancavilla (Catania, Italy), a new asbestiform fiber, named fluoro-edenite (NaCa2Mg5(Si7Al)O22F2), was found in a stone quarry use for local building industry and in the lung tissue of an 86 years old woman who died from pleural mesothelioma. As a consequence the Italian Ministry of the Environment has included the Biancavilla site in the National Priority List. In this study, a point of view on the results from a large scale environmental monitoring program conducted for the implementation of the site investigation is presented. The obtained dataset from the environmental monitoring program results in more than 3,000 values of concentration of asbestos like fibers and fluoro-edenite fibers in air, water and top soil. These data are spatially and temporally distributed in the Biancavilla site, therefore the development and application of a Geographic Information Systems (GIS) was very useful to review, manage and analyze the obtained data and to give direction to the stakeholders in order to define the required remediation activities. A WebGIS was also developed to provide a rapid GIS access and data management by various control bodies.

Integrated anaerobic–aerobic systems for solid waste treatment

Abstract: ACEA is a modern Italian multi-utility company, which currently provides services for Municipalities, private companies and citizens. The Waste Treatment facilities of ACEA Pinerolese Industriale S.p.A. have been developed during years 2001–2003. The entire process is based on the connection of four different treatment plants (anaerobic digestion, composting plant, wastewater treatment plant and a landfill), where both anaerobic and aerobic digestion take place. The efficiency of the system is aligned to literature data for best efficiency as we can see from the 0,534 m3/KgVSfed of the specific biogas production and from the substrate removal effectiveness reaching 69 % in 4 years time data. Moreover, the amount of energy consumed by the anaerobic digestion (AD) treatment is less than the 27 % of the energy produced by the AD system, which is a remarkable gain in efficiency.

Membrane science and technology: leader in water treatment industry

Abstract: Filtration and separation can represent as much as 80 % of the operating costs for many industries, and membrane separations are gaining acceptance as a cost-effective option in many production settings. Newer, more efficient membrane separation techniques can lead to more streamlined production and produce significant improvements in quality (http://www.mastcenter.org/default.htm). It is exciting to note the significant growth of membrane activities in the world, particularly in the area of desalination and municipal water purification. This interest is documented also by the industrial realization in reverse osmosis units, ultrafiltration and membrane bio-reactor. Also at fundamental research level, various new institutes are focusing their attention on the development of membrane research projects. This web alert overviews some important websites sharing knowledge on membrane science and technology.