Polycyclic aromatic hydrocarbons (PAHs) are an important class of chemical pollutants that constitute a major component of total hydrocarbons in crude oils. Based on their poor water solubility, toxicity, persistence and potential to bioaccumulate, these compounds are recognized as high-priority pollutants in the environment and are of significant concern for human health. At oil-contaminated sites, PAH-degrading bacteria perform a critical role in the degradation and ultimate removal of these compounds. In April 2010, enormous quantities of PAHs entered the Gulf of Mexico from the thousands of tons of oil that were released from the ill-fated drilling rig Deepwater Horizon. In the ensuing months after the spill, intense research efforts were devoted to characterizing the microorganisms responsible for degrading the oil, particularly in deep waters where a large oil plume, enriched with aliphatic and low molecular-weight aromatic hydrocarbons, was found in the range of 1,000–1,300 m. PAHs, however, were found mainly confined to surface waters. This paper discusses efforts utilizing DNA-based stable isotope probing, cultivation-based techniques and metagenomics to characterize the bacterial guild associated with PAH degradation in oil-contaminated surface waters at Deepwater Horizon.

Waste is unwanted or useless material. It is widely recognized that waste materials are valuable resources, whilst there is debate as to how this value is best realized. Re-use, recycling and energy recovery are being applied to regulated wastes. Yet, while recycling and re-use are increasing, the overall amounts of waste are still growing, and there is an increasing demand for primary resources and stress on eco-systems. In this webalert, we will focus on some important websites which provide readers with more informative resources related to waste management.

Vermicomposting has been arising as an innovative ecotechnology for the conversion of various types of wastes into vermicompost. Vermicompost is humus like, finely granulated and stabilized material which can be used as a soil conditioner to reintegrate the organic matter to the agricultural soils. Industrial wastes remain largely unutilized and often cause environmental problems like ground and surface water pollution, foul odours, occupying vast land areas etc. Non-toxic and organic industrial wastes could be potential raw material for vermitechnology. In the last two decades, vermitechnology has been applied for the management of industrial wastes and sludges and to convert them into vermicompost for land restoration practices. The success of the process depends upon several process parameters like quality of raw material, pH, temperature, moisture, aeration etc., type of vermicomposting system and earthworm species used. The review discusses the vermitechnology and the present state of research in the vermicomposting industrial sludges and wastes.

Metal accumulating plants exposed to toxic levels of zinc (Zn) and cadmium (Cd) uptake metals through extracellular and intracellular complexation with inorganic and organic ligand formation. However, little is known about the nature and formation mechanism of these metal–ligand complexes. Though, Zn and Cd have many similar chemical properties, yet their complexation and compartmentalization in plants vary with plant species. In principal, the question arises what factors govern Zn and Cd partitioning in plants? What form of the metal is taken up by the root, and is further distributed and accumulated in both vegetative and reproductive tissues? Therefore, the aim of present study is to address several questions concerning the mechanisms of Zn and Cd coordination and compartmentalization in plants using X-ray absorption spectroscopy (XAS) technique. XAS allows direct determination of elemental oxidation states and coordination environments in different plant tissues. This review article briefly explains some other important techniques of XAS; EXAFS (extended X-ray absorption fine structure) and XANES (X-ray absorption near edge structure), which are employed for determining Zn and Cd complexation within the plant. Therefore, In present review, the predominant as well as the minor chemical forms of Zn and Cd present in particular plant tissue have been discussed which could give better insight towards metal accumulation and detoxification mechanisms operated in plants. This information could assist in employing suitable hyperaccumulator plants for metal phytoextraction and reclamation of metal contaminated sites.

Industrialization and urbanization activities lead to extensive environmental problems and one of the most challenging problems is heavy metal contamination. Heavy metal is responsible for causing adverse effect on human health through food chain contamination. To minimize the effect, different methods are being used for decreasing heavy metal load into the food chain. Most of the traditional methods are either extremely costly or it simply isolate the contaminated site. A promising, relatively new technology for removal of heavy metal from contaminated sites is phytoremediation. There are numerous crops such as sunflower (Helianthus annus), maize (Zea mays), mustard (Brassica compestris), barley (Hordeum vulgare), beet (Beta vulgaris), bitter Gourd (Momordica charantia), brinjal (Solanum melongena), cauliflower (Brassica oleracea var. botrytis), chilli (Capsicum annum), coriander (Coriandrum sativum), fenugreek (Trigonella foenum-graecum), garlic (Alium sativum), ivy gourd (Coccinia indica), lufa (Luffa acutangula), lady’s finger (Abelmoschus esculentus), mint (Mentha piperata), radish (Raphanus sativus), spinach (Spinacia oleracea), tomato (Lycopersicom esculentum), and white gourd (Lagenaria vulgaris) used for remediation of heavy metal. The efficiency of the phytoremediation crops depends upon their biomass production and ability of metal accumulation in their harvestable organs. In addition to this there are some biotechnological approaches for enhancing the property of hyper accumulator plant for metal remediation. Various potential remediation techniques are available that can be used to reduce the heavy metal contamination. Research related to relatively new technology should be promoted and emphasized and expanded in developing countries where heavy metal pollution has already touched alarming level. In the above context present review deals with different approaches to reduce the availability of heavy metal from soil to plants.

Key to effective disinfection byproduct (DBP) management is source water control and management, and more specifically, organic matter (OM) control and management. However, the content and character of OM in source waters is spatially and temporally variable, and the prediction of its composition is challenging. Water treatment companies require adequate analytical techniques for OM characterisation to maintain the operation of the water supply and treatment systems adjusted to constantly changing environmental conditions. There is a requirement, therefore, for an improved understanding of OM composition and character in source water, how that composition and character varies with flow conditions, and how this impacts on drinking water treatment. This paper demonstrates that fluorescence spectroscopy offers a potential alternative to other analytical methods of OM characterisation. The advantages of fluorescence include rapid, sensitive and selective characterisation of OM, no sample pre-treatment, small sample volume, and the potential for on-line monitoring incorporation. Fluorescence can provide useful information on OM reactivity and treatability together with an indication of the OM sources (allochthonous or autochthonous). The paper discusses a body of literature which has identified relationships between fluorescence spectra and OM physico-chemical properties (i.e. degree of hydrophobicity, microbial content), has applied fluorescence spectroscopy to characterise the changes in OM upon disinfection, and has related the fluorescence properties to DBP formation. Further work is required in the robust management of data arising from fluorescence spectroscopy analysis and, in particular, Excitation Emission Matrices. Consideration must be given as to how the data might best be employed to greatest effect on a routine basis at WTW.

L. camara is a terrible weed, exerting huge detrimental effect on biodiversity. Its leaves and flowers contain toxins, lantadene A and B, so unfit for herbivory by ruminants. This weed stunts the growth of neighbouring plants owing to the allelopathic effect of its root leachate. The seeds tide over adverse period and germinate when favourable conditions prevail. Further, pruning makes the thicket denser. Almost all removal strategies of this weed have been unsuccessful so far. So, management of this weed by utilization is required. Recent studies have reported that L. camara improves soil quality by enriching it with nitrogen, exhibits termiticidal effect, acts as lignocellulosic substrate for cultivation of edible mushrooms, acts as potential insecticide and fumigant for grains storage against weevils, antifungal agent, herbicide against water hyacinths. L. camara has bioactive ingredients exhibiting anticancer, antiulcerogenic, hypolipidemic, larvicidal and anti-inflammatory activity. L. camara fibre has been reported to be suitable candidate as reinforcement in biomaterials. Also, this plant extract is effective in bovine dermatophilosis therapy. L. camara has also immense industrial importance, as a source of oleanolic acid and carboxymethylcellulose. L. camara biomass can be implicated as a substrate for bioethanol and biogas production. This invasive weed can also serve as livelihood options, as the woody twigs can be utilized for aesthetic and durable furniture making apart from the use as firewood. The latest published papers on the novel uses of L. camara have been reviewed, with the objective of providing a thrust to weed management by utilization.

Laccases (benzenediol: oxygen oxidoreductase, EC 1.10.3.2) are multi-copper-containing enzymes capable of catalyzing the oxidation of a wide range of phenolic and non phenolic aromatic compounds. The available data indicates that laccases from prokaryotes are promising biological tools for green chemistry based applications, especially in decolorization of industrial textile dye effluents which constitute a major threat to soil and ground water reservoirs worldwide. Another appropriate application of prokaryotic laccases is bio-bleaching of different kind of pulps where there is indiscriminate use of hazardous chlorine based chemicals for brightness of the paper. In recent years, researchers have shown interest in the identification and characterization of laccases from prokaryotic sources. This catalyst is not commonly reported from this kingdom, although prokaryotes have immense environmental adaptability and biochemical versatility. Moreover, true laccases or laccase-like enzymes exist in many gram-negative, gram-positive bacteria and actinomycetes. Corresponding genes have been identified and functionally expressed in genetically developed hosts. This review summarizes the research efforts to characterize laccases and their properties from different prokaryotic sources, including bacteria and actinomycetes.

Anaerobic digestion of waste activated sludge (WAS) is most commonly used at wastewater treatment facilities to stabilize the sludge. However, poor biodegradation efficiency of sludge and longer retention times (20–30 days) are the major limitations of anaerobic digestion method, which can be overcome by disintegrate the sludge and make intracellular material readily available to anaerobic biodegradation. Several sludge disintegration techniques (Thermal, chemical and mechanical) and their combinations were studied previously in order to improve the anaerobic digestibility of sludge, reduce the sludge retention time and enhance the production of biogas. However, none of the pretreatment technique shows a real breakthrough in enhancement of anaerobic digestibility of WAS due to associated drawbacks, such as high operational and capital cost, poor sanitization and energy intensive. On the other hand, hybrid pretreatment techniques endow with promising outcomes through neutralizing the associated drawbacks with individual pretreatment techniques. Nevertheless, the research on the application of hybrid pretreatment techniques is in its infant stage, presently. Therefore, the satisfactory research in this direction can lead to policy maker and environmental protection agency to select more robust and sustainable solution for sludge treatment. This review encompasses the up-to-date information about the thermal, chemical and mechanical sludge disintegration techniques (principle, performance at lab, pilot and full scale, advantages and disadvantages). A comparative evaluation of these techniques are also presented in terms of COD solubilization, dewaterability, pathogens removal, lab/pilot/full scale application, capital and, operation and maintenance cost involved and energy requirement.

Fossil fuels are the lifeblood of our society and for many others around the world. The environmental pollution due to the use of fossil fuels as well as their gradual depletion make it necessary to find alternative energy and chemical sources that are environmentally friendly and renewable. Palm oil mill effluent (POME), a strong wastewater from palm oil mills, has been identified as a potential source to generate renewable bioenergies through anaerobic digestion. Thus, it has received considerable attention as feedstock for producing various value added products such as methane gas, bio-plastic, organic acids, bio-compost, activated carbon, and animal feedstock. Lipids are one of the major organic pollutants in POME. Furthermore, waste lipids are ideal potential substrates for biogas production, since theoretically more methane can be produced, when compared with proteins or carbohydrates. The objective of this review paper is to disscuss the microbial communities involved in the anaerobic degradation of long chain fatty acid and bioenergies and by-products from POME. With these options (Renewable and sustainable bioenergies) we can help phase out our dependency on fossil fuels and find clean, efficient, sources of power.