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As reported recently by the present authors, vermicomposting by the epigeic earthworm Eisenia fetida transforms the highly ligninous and allelopathic aquatic weed salvinia (Salvinia molesta) into a benign organic fertilizer. The present study was carried out with four other earthworm species, including three epigeic species of different sizes and phytophagic habits: Eisenia andrei, Lumbricus rubillus, and Perionyx sansibaricus. One anecic species, with geophytophagous habits, was also explored for comparison: Drawida willsi. The objective was to see whether the type of salvinia transformation caused by E. fetida is a general phenomenon or whether there are significant differences in the nature of biocomposts generated by different earthworm species. Accordingly, the characteristics of the biocomposts separately generated by each of the six species mentioned above were assessed with UV-visible spectrophotometry, Fourier-transform infrared spectrometry, differential scanning calorimetry, thermogravimetry, and scanning electron microscopy. The studies reveal that, with minor variations, the biocomposting by all four species was able to remove the intransigence of salvinia and impart plant/soil-friendly attributes to it in substantial measures. All the findings obtained with different techniques corroborated each other in arriving at this conclusion. Hence, it can be said that, in general, biocomposting by earthworms takes away the toxicity of pernicious weeds such as salvinia, converting them into plant-friendly and soil-friendly biofertilizers.

Vermicompost derived exclusively from ipomoea (Ipomoea carnea), a weed notorious for its toxic and allelopathic characteristics, was explored for its potential use as an organic fertilizer. Ipomoea vermicompost (IVC) at four levels (0, 2.5, 3.75, and 5 tonnes/ha) was explored for its effect on the germination, growth and fruition of ladies finger (Abelmoschus esculentus) in appropriately replicated experiments. It was seen that IVC encouraged the germination and growth of ladies finger at all levels of the IVC application, and best results were obtained in 5 t/ha treatments. The positive effect occurred at all stages of A.esculentus cultivation ─ from germination of its seeds to all the vegetative growth phases and the fruit yield. There was also improvement in the quality of fruits in terms of mineral, protein and carbohydrate contents, and reduction in the disease incidence and pest attacks, due to the IVC application. The studies reveal that vermicomposting enables ipomoea to acquire all the qualities of a good organic fertilizer with simultaneous loss of its toxicity and allelopathy. The findings raise hopes that the enormous quantities of ipomoea biomass that is generated across the world, and which presently goes to waste, may become utilizable in producing organic fertilizer. Keywords: Ipomoea, Toxicity, Allelopathy, Vermicomposting, Biofertilizer, Biopesticide

Efficacy of all the existing transient models for forecasting the area attained by accidentally spilled liquid fuels has been sought to be assessed on the basis of experimental data available in prior art. Of the two models for which required inputs are available in the prior art, the model of Huppert (1982) is able to forecast spill area with much greater precision than the model of Raj and Kalelkar (1974). Both the models give better predictions when the spill volume is higher and the spill duration is lower but neither model yields a correlation between the accuracy of the spill area forecast and the nature of the spilled liquid or the receiving surface.

A circular (close-loop) biorefinery, which integrates wastewater treatment with the generation of an energy precursor and organic fertilizer, tested at the level of a pilot plant treating 54,000 L per day (LPD) of sewage, is described. In the biorefinery’s first stage, sewage was treated in a novel SHEFROL® (sheet-flow-root-level) bioreactor at a very rapid rate, indicated by a hydraulic retention time of a mere 6 h, to a level that met the prevailing national standards for the discharge of treated sewage. The main bioagent of the reactor—water hyacinth—was then processed for the generation of energy precursors. For this, volatile fatty acids (VFA) were extracted in a simple batch reactor operating at ambient temperature and pressure. The ‘spent’ weeds were then converted into organic fertilizer, also at ambient temperature and pressure, by the high-rate vermicomposting process earlier reported by the authors. In this manner, wastewater treatment, energy production, and the generation of a fertilizer were achieved rapidly and efficiently, creating a circular close-loop system that required very little energy and materials and generated almost zero net waste.

The authors wish to make the following corrections to this paper [...]

Hypotermes obscuriceps is the most abundant of termite species found in North-eastern Puducherry. It has been seen to assimilate ligninous waste kept for degradation in the termireactors designed earlier by the authors by the process of termigradation. Termigradation is a termite-based biodegradation process and involves attracting termites towards the ligninous waste in specially designed reactors. Such reactors are kept in pits or aboveground near termite mounds. In order to increase the number of termites that will move towards the feed kept in such termireactors, 2-Phenoxyethanol (2-PE) was explored in the laboratory for making trails that may attract H. obscuriceps. Five different concentrations of 2-PE, ranging from 0.1 to 0.0005% were explored and in controlled experiments, the numbers of termites that followed the trails made by these levels of 2-PE as a function of time were determined. It was seen that all the trails that contained 2-PE attracted H. obscuriceps and none was toxic to termites for the first 60 minutes.

Background Any manner of development can be sustainable only if the waste generated by it is not allowed to accumulate but is fully reused/recycled/recovered. Among the strategies to attain this goal have been the attempts to recover energy from municipal solid waste (MSW). About 60% of MSW is carbonaceous, consisting of materials which can either be biodegraded into fuels like methane or incinerated, thereby generating utilizable energy. MSW also contains several components—like metallic scrap and glass pieces—which can be reused or recycled, thereby achieving energy conservation. Given these attributes, MSW appears to be a potential source of energy and resources. Indeed, this belief that MSW is usable if only we try sincerely enough to do so prompts most of us to keep generating much more MSW than is warranted. But how realizable really is the energy potential of MSW? What perils loom into view when we actually set out to utilize MSW as an energy source? The present study addresses these crucially important questions. Methods The work is based on a critical content analysis of the prior art. Results The generation of MSW has consistently outpaced the world’s efforts to dispose of it cleanly, and the energy (and material) recovery from MSW is easier said than done. In most instances, what is technically feasible is economically unfeasible. And what is economically feasible—such as setting the waste on fire as is often done in developing countries—is exceedingly harmful to the environment and the human health. Measures such as sanitary landfilling and incineration create as many new problems as the old ones they solve. Moreover, despite the use of these less-than-adequate technologies, a major portion of MSW generated in the world lies untreated. Conclusions As the MSW output is expected to double by 2025, this situation is only set to become worse. Rising tides of E-waste would compound the problem even further. Hence, enormous stress should be put on the reduction of MSW generation by controlling wanton consumerism and wastage, rather than continuing with it in the false hope that technology will soon provide a magical solution and eliminate the problem.

The design and testing of a novel vermicomposting system, acronymed FLUVTS ─ FLippable Units Vermireactor Train System ─ is presented. It enables rapid vermicomposting of paper waste without the need of pre-composting and requires animal manure supplementation to the extent of only 10:1 paper: manure mass ratio in contrast to reported systems which must have 50% or more of the feed mass as animal manure. Moreover, the system enables the vermicomposting to be accomplished at a high rate, achieving near-total convertion of feed to vermicast at solid retention times of just 30 days in comparison to conventional systems which take 90–120 days for the same process. Uninterrupted vermireactor operation for 6 months, during which the feed was put in and its vermicompost harvested once in 30 days, demonstrates the robustness and the consistency of the system. The suitability of the paper-waste vermicompost as an organic fertilizer was then tested in terms of it's effect on seed germination and early growth of four food plants chilly (Capsicum annuum), ladies finger, (Abelmoschus esculentus), cucumber (Cucumis sativus), and tomato (Lycopersicon esculentum). In general, the paper waste vermicompost when applied at levels

Very large quantities of flammable substances are produced, transported, and refilled across the world. Of these some, like gasoline and diesel, are liquids at normal temperature and pressure while some others – like liquid petroleum gas (LPG – are pressure liquefied gases. Ever so often accidental spills of these chemicals occur. While some spills are contained before they could do much damage, many others catch fire and often also lead to massive explosions. Indeed, accidental spills have been the initiators of the majority of industrial disasters the world has seen. Given the exceptional importance associated with the containing and controlling of accidental spills, it is essential to understand the factors which effect the spill dynamics so that ways to reduce the risk posed by such spills can be devised. But even as a great deal of work has been done on the dynamics of spills occurring on flat surfaces, little past effort is on record pertaining to the study of spills occurring on inclined surfaces. This is surprising because the spillways actually provided in the industries for large storage tanks invariably have downward slope to enable quick drainage of the flammable liquid away from the storage tank in the event of an accidental leak. The present work is an attempt to make some contribution towards the understanding of the dynamics of spillage of flammable liquids on inclined surfaces. When accidental spills occur in the open – during transportation by road, railroad, or pipeline – the receiving surfaces can be porous and the liquid can percolate down, making environmental contamination that much difficult to remediate. To incorporate this aspect in the present study we have chosen porous surfaces and studied the dynamics of the spill of three different flammable liquids on them at angles of inclination varying from zero to 20°.

The existing methods for calculating overpressure resulting from a vapour cloud explosion (VCE) were tested for their ability to predict overpressures from unconfined hydrogen explosions. For it, data collated from five reported experimental investigations on open air hydrogen explosions covering 1.4–300 m3 volume of hydrogen-air mixtures and concentrations ranging 20–57% were employed. It was found that the existing VCE models are grossly inadequate for predicting the overpressure generated by unconfined hydrogen explosions. A new method was then developed for assessing overpressures from hydrogen explosions for a given concentration and volume of release based on Sach's scaling laws. The new model has much greater ability to fit the experimental data, hence much stronger ability to forecast the severity and consequences of hydrogen-based VCEs compared to the existing models.

The ornamental plant Alternanthera ficoidea (also named A. tenella), which is common and widespread throughout the tropics and is being increasingly regarded as an invasive, problematic weed, has been explored as a bioagent in greywater treatment. In the recently developed SHEFROL® bioreactor, it was seen to treat greywater of varying strengths (250–1,300 mg/L chemical oxygen demand, COD) quickly and substantially to the extent of 75–77%. Biological oxygen demand (BOD), nitrogen, phosphorus, suspended solids, and heavy metals copper, nickel, manganese, and zinc were also removed to the extents of 83.5, 94.9, 33.1, 27.0, 44.8, 27.5, 38.2, and 43.2%, respectively. As all this was achieved in a single pot, single step, and in a simple reactor operation, at hydraulic retention times of a mere 6 h, it shows the process to be several times more efficient as well as potentially less expensive than the conventional treatment systems which utilize macrophytes in tanks or constructed wetlands.

Purpose In a novel attempt, vermicompost derived from an intransigent and noxious weed salvinia was assessed for its fertilizer value and pest repellent properties. Methods In outdoor experiments which simulated the way vegetables are cultivated by farmers, ladies finger (Abelmoschus esculentus) seeds were germinated and grown in soil supplemented with salvinia vermicompost at four levels: 0 (V0), 2.5 (V1), 3.75 (V2) and 5 (V3) t/ha. Besides assessing germination success and subsequent growth, yield, and biochemical content of the plants, the impact of pest attacks on them was also studied. Results Salvinia vermicompost significantly enhanced germination success, growth, and yield of the plants. Maximum growth in terms of shoot length (96.2 cm), root length (48.2 cm), shoot and root dry weight (23.31, 7.96 g), stem diameter (14.04 mm), and number of leaves and branches (26.8, 4.8) was recorded in V4 (5t/ha). Likewise, the mineral and biochemical content in vermicompost-treated plants was significantly higher than in the controls. The vermicompost also induced resistance in plants against pests and disease. Compared to the controls, vermicompost had reduced the fruit borer infection by 65, 78 and 82% in V1, V2 and V3, respectively. Conclusion The toxicity of salvinia is largely eliminated when it is vermicomposted, and the product acquires the qualities of a good organic fertilizer. The present work can potentially lead to the development of an inexpensive, sustainable and eco-friendly method of utilizing billions of tons of phytomass that is generated annually by salvinia, and which presently goes to waste.

A systematic survey of termite species in Northeastern Puducherry which is part of peninsular India, was carried out. As there is no pre-existing report on the richness or diversity of termifauna in this region, the present work aims to fill this major knowledge gap. The findings are discussed in the context of the quantitative studies on termifauna carried out across the world, as also in terms of the defining traits of the species identified in the survey vis a vis their possible use in biodegrading ligninous biowaste. The latter aspect is particularly relevant to the controlled use of termites by the process named ‘termigradation’, which denotes termite-based biodegradation of waste. Key words: Termites, termigradation, indices, India, Puducherry.

When two or more pool fires burn in close enough proximity to influence one another, the resultant combination is termed ‘multiple pool fire’ (MPF). Even though MPFs occur fairly often in chemical process industries, with highly destructive consequences, much lesser work has been done towards simulation, modeling, and control of MPFs than on stand-alone pool fires. Among the factors which strongly influence the interaction among the MPFs, and the consequent damage MPFs may cause, the most important is the type of fuel contained in the individual pools. This aspect affects the temperatures of the interacting flames, their soot production, and the resultant radiation load. However, studies to dynamically model this aspect have not been carried out so far. In this paper an attempt has been made, arguably the first of its kind, to explore the efficacy of computational fluid dynamics (CFD) in simulating the effect of fuel types on MPF clusters. A fair agreement has been found between the CFD simulation and the experimental findings reported by Vincent and Gollahalli (1995). The agreement between the experimental data and CFD simulation results is good considering the fact that the soot production has not been accounted by us.

The composition and the fertilizer value of vermicompost derived solely from ipomoea, a weed known for its toxicity and allelopathy, has been studied employing Fourier transform Infrared Spectroscopy (FT-IR) and plant bioassay (germination and seedling growth). The impact of ipomoea’s vermicompost on the physicochemical and biological characteristics of the soil was also studied. FT-IR analysis revealed that chemical compounds that are responsible for the deleterious effect of ipomoea are largely destroyed in the course of ipomoea’s vermicomposting. The ipomoea vermicompost was seen to be a good organic fertilizer as it significantly enhanced germination success, promoted growth of the seedlings and induced plant friendly physicochemical and biological features to the soil. The studies raise the possibility that very large quantities of biomass that are generated by ipomoea across the world can be utilized in producing organic fertilizer through vermicomposting. This may also provide a means of checking the seemingly unstoppable spread of ipomoea and cushioning its adverse impacts.

Understanding the link between termites' impact on ecosystem functioning and their ecological needs remains a key question in ecology. This study focused on the influence of the fungus-growing termite species, Hypotermes obscuriceps, on soil properties in Southern India. This species produces soil sheetings and mounds on the ground. In contrast to other termite species, such as those belonging to the Macrotermes and Odontotermes genera, which produce mounds to live in, H. obscuriceps excavates soil above ground for constructing its chambers below ground. Using a captive colony of H. obscuriceps growing up in control conditions, we measured the soil properties (carbon content, particle size distribution, pH, electrical conductivity and concentration in soluble anions and cations) of its mound and of the sheetings it produced over the leaves of Acacia auriculiformis and on the branches of Ipomoea carnea and Lantana camara. The physical and chemical properties of H. obscuriceps mounds were very similar to those of the surrounding soil and even if rain erodes these mounds in the field, it is likely to have only a small effect on the resulting run-off water quality. In contrast, sheetings have higher clay and C contents than the surrounding soil. Their degradation by rain is likely to be associated with soil detachment and F-, Cl- and K+ export in water runoff and/or leachate. In conclusion, this study shows that this species impacts soil properties more through the construction of sheetings than mounds. This difference is explained by the ecological needs of termites. While H. obscuriceps is not dependent on soil mound properties for survival, soil sheetings' properties are essential for providing them a protective cover.

Paddy fields, which are shallow man-made wetlands, are estimated to be responsible for ~11% of the total methane emissions attributed to anthropogenic sources. The role of water use in driving these emissions, and the apportioning of the emissions to individual countries engaged in paddy cultivation, are aspects that have been mired in controversy and disagreement. This is largely due to the fact that methane (CH4) emissions not only change with the cultivar type but also regions, climate, soil type, soil conditions, manner of irrigation, type and quantity of fertilizer added&mdash, to name a few. The factors which can influence these aspects also encompass a wide range, and have origins in causes which can be physical, chemical, biological, and combinations of these. Exceedingly complex feedback mechanisms, exerting different magnitudes and types of influences on CH4 emissions under different conditions, are operative. Similar is the case of nitrous oxide (N2O), indeed, the present level of understanding of the factors which influence the quantum of its emission is still more patchy. This makes it difficult to even understand precisely the role of the myriad factors, less so model them. The challenge is made even more daunting by the fact that accurate and precise data on most of these aspects is lacking. This makes it nearly impossible to develop analytical models linking causes with effects vis a vis CH4 and N2O emissions from paddy fields. For situations like this the bioinspired artificial intelligence technique of artificial neural network (ANN), which can model a phenomenon on the basis of past data and without the explicit understanding of the mechanism phenomena, may prove useful. However, no such model for CH4 or N2O has been developed so far. Hence the present work was undertaken. It describes ANN-based models developed by us to predict CH4 and N2O emissions using soil characteristics, fertilizer inputs, and rice cultivar yield as inputs. Upon testing the predictive ability of the models with sets of data not used in model development, it was seen that there was excellent agreement between model forecasts and experimental findings, leading to correlations coefficients of 0.991 and 0.96, and root mean square error (RMSE) of 11.17 and 261.3, respectively, for CH4 and N2O emissions. Thus, the models can be used to estimate CH4 and N2O emissions from all those continuously flooded paddy wetlands for which data on total organic carbon, soil electrical conductivity, applied nitrogen, phosphorous and potassium, NPK, and grain yield is available.

Vermicompost, which had been derived solely by the action of the epigeic earthworm Eisenia fetida on parthenium (Parthenium hysterophorus), was tested for its impact on the germination and early growth of green gram (Vigna radiata), ladies finger (Abelmoschus esculentus) and cucumber (Cucumis sativus). Seedlings were germinated and grown in soil amended with 0 (control), 0.75, 1.5, 2, 4, 8, 20 and 40% (by weight) parthenium vermicompost. Even though parthenium is known to possess strong negative allelopathy, as also plant/animal toxicity in other forms, its vermicompost (VC) manifested none of these attributes. Rather the VC enhanced germination success, introduced plant-friendly physical features in the container media, increased biomass carbon, and was seen to promote early growth as reflected in several morphological and biochemical characteristics in plants which had received parthenium VC in comparison to those which had not. All these effects were statistically significant. Fourier Transform Infrared (FTIR) Spectrometry revealed that the phenols and the sesquiterpene lactones that are responsible for the negative allelopathic impact of parthenium were largely destroyed in the course of vermicomposting. FTIR spectra also indicated that lignin content of parthenium was reduced during its vermicomposting. The findings open up the possibility that several other invasives known for their negative allelopathy and toxicity may also produce vermicompost which may be plant-friendly and soil-friendly. It also makes it appear possible that the huge quantities of phytomass that is generated annually by parthenium can be gainfully utilized in producing organic fertilizer via vermicomposting, thereby providing a means of exercising some control over parthenium's rampant growth and invasion.

In evidently the first study of its kind, vermicompost derived solely from salvinia (Salvinia molesta Mitchell), arguably the world’s most invasive and dominant aquatic weed, has been assessed for its nature and composition. Salvinia is known to contain exceptionally high concentrations of polyphenols, and has unusually ligneous leaves—the two attributes that make it strongly allelopathic and hardy, enabling it to elbow out other vegetation. The present study, supported by UV–vis and FTIR spectrometry, thermogravimetric and differential thermal analysis, and GS-MS analysis, reveals that upon vermicomposting salvinia loses its allelopathy. It happens because chemicals responsible for the alleopathy of salvinia are destroyed, transforming the weed into a potent organic fertilizer. Much of the salvinia’s lignin is also biodegraded. Scanning electron microscopy shows marked disaggregation of the material in the vermicompost as compared to well-formed matrix of salvinia leaves. The findings open up the possibility of utilizing billions of tonnes of salvinia biomass – which not only goes to waste at present but is also a cause of serious harm to the environment – in making organic fertilizer.

Livestock production is among the most ecologically harmful of all anthropogenic activities. It has massive direct and indirect contributions to global warming besides causing widespread ecodegradation in other ways. But livestock production cannot be reduced because, as it is, the global demand for animal protein is far higher than the supply. Whereas in developed countries people get about 95 g of protein per day in their diets, of which nearly 60% is made up of animal protein, in developing countries the protein intake is only about 45 g/day and of it a mere 15% is made up of animal protein. This gap in the availability of animal protein for a large fraction of the world's population who desires it, is continuing to increase because of the increased globalization-induced rich-poor gap across the world. Besides the fact that conventional ways of animal protein production using livestock―chicken, goat, pork, beef―are highly eco-degrading; in terms of availability of pasture lands as well as enhancement in productivity of edible zoomass with inputs from science and technology, the upper limits of animal protein production have already been reached. The ocean-based food production has similarly reached unsustainable levels. As a consequence, now onwards the demand will increasingly outstrip supply. In this backdrop it is essential that we look at the potential of minilivestock, especially insects. As brought out in this paper, human beings have evolved as entomophagous species and there are even suggestions that some of the special proteins and other constituents present in the insects might have helped the human brain to develop as rapidly as it did to enable its evolution into Home sapiens. Moreover, several species of insects are prized delicacies in advanced countries like Japan, Australia, and Europe. Hence, insects are not restricted to being ‘subsistence food’ of grossly impoverished people as one might imagine though a lot of species do help the world's poor to survive. If other virtues of insects are considered― especially their high food-to-zoomass conversion efficiency, quick growth rate, enormous variety, and world-wide distribution―their potential as a much more sustainable source of animal protein than conventional livestock would become obvious.

A rapid, reproducible single step method is proposed for synthesizing platinum nanoparticles using an invasive weed lantana (Lantana camara, L). The method involves mixing of platinum (VI) solution, lantana leaf extract and ascorbic acid in appropriate concentrations and keeping the mixture at 95°C for 8 min. The collective action of ascorbic acid and leaf extract reduced the chloroplatinic acid to platinum nanoparticles and leaf extract then served the additional purpose of stabilizing the nanoparticles. The resulting nanoparticles have an average size of 35 nm and crystallized in face centred cubic symmetry. The course of the synthesis was trekked by UV-visible spectrophotometry and the characterization of the nanoparticles was done with scanning electron microscopy and confocal laser Raman spectroscopy. Particle size distribution was estimated by dynamic light scattering and the crystal structure was determined by XRD. The purity of the product was checked by EDAX.

A biomimetic method of gold nanoparticles synthesis utilizing the highly invasive aquatic weed pistia (Pistia stratiotes) is presented. In an attempt to utilize the entire plant, the efficacy of the extracts of all its parts – aerial and submerged – was explored with different proportions of gold (III) solution in generating gold nanoparticles (GNPs). The progress of the synthesis, which occurred at ambient temperature and pressure and commenced soon after mixing the pistia extracts and gold (III) solutions, was tracked using UV–visible spectrophotometry. The electron micrographs of the synthesized GNPs revealed that, depending on the metal-extract concentrations used in the synthesis, GNPs of either monodispersed spherical shape were formed or there was anisotropy resulting in a mixture of triangular, hexagonal, pentagonal, and truncated triangular shaped GNPs. This phenomenon was witnessed with the extracts of aerial parts as well as submerged parts of pistia. The presence of gold atoms in the nanoparticles was confirmed from the EDAX and X-ray diffraction studies. The FT-IR spectral study indicated that the primary and secondary amines associated with the polypeptide biomolecules could have been responsible for the reduction of the gold (III) ions to GNPs and their subsequent stabilization.

We demonstrate a simple, straightforward, clean-green, single pot approach for the synthesis of bimetallic Ag/Au nanoparticles (BNPs) by using a highly invasive terrestrial weed coral vine (Antigonon leptopus). Aqueous extracts of the weed were found to reduce the metal ions to form nanosised aggregates and then stabilise them by preventing further aggregation. The efficacy of the extracts of all its parts was explored by varying the stoichiometry of reactants, temperature, pH and reaction time. The electron micrographs of the synthesised BNPs indicated the presence of particles of predominantly spherical shapes in sizes ranging from 10 to 60 nm. The presence of gold and silver atoms was confirmed from the energy dispersive X-ray, X-ray photoelectron and X-ray diffraction studies. The Fourier transform infra-red spectroscopic spectral study indicated that the phenolics (including flavonoids) and proteins contained in the plant extract could have been responsible for the formation and stabilisation of the ...

In nature earthworms process enormous quantities of leaf litter and other forms of plant debris by ingesting them and converting them into vermicast. The latter is widely recognized as a soil-friendly and plant-friendly organic fertilizer. Earthworms also consume animal droppings but the quantities of plant biomass processed by earthworms are several times greater than the quantities of zoomass they handle. Yet, when controlled vermicomposting is done to process biodegradable solid waste, it is almost entirely focused on animal manure or food waste. Leaf litter, paper waste, terrestrial/aquatic weeds, or crop waste is rarely vermicomposted on a large scale. This paper assesses the attempts made so far to vermicompost plant-based substrates and tries to identify the reasons why the laboratory-scale studies have not evolved into larger-scale initiatives in vermicomposting such substrates. Emerging evidence of the efficacy of the high-rate vermicomposting technology in the direct processing of phytomass into fertilizers has been presented.

Volatile fatty acids (VFAs), comprising mainly of acetic acid and lesser quantities of propionic and butyric acids, are generated when zoomass or phytomass is acted upon by acidogenic and acetogenic microorganisms. VFAs can be utilized by methanogens under anaerobic conditions to generate flammable methane–carbon dioxide mixtures known as ‘biogas’. Acting on the premise that this manner of VFA utilization for generating relatively clean energy can be easily accomplished in a controlled fashion in conventional biogas plants as well as higher-rate anaerobic digesters, we have carried out studies aimed to generate VFAs from the pernicious weed ipomoea (Ipomoea carnea). The VFA extraction was accomplished by a simple yet effective technology, appropriate for use even by laypersons. For this acid-phase reactors were set, to which measured quantities of ipomoea leaves were charged along with water inoculated with cow dung. The reactors were stirred intermittently. It was found that VFA production started within hours of the mixing of the reactants and peaked by the 10th or 11th day in all the reactors, effecting a conversion of over 10% of the biomass into VFAs. The reactor performance had good reproducibility and the process appeared easily controllable, frugal and robust.

The paper presents a new method for the biomimetic synthesis of gold nanoparticles (GNPs), in which a highly invasive and harmful weed Ipomoea carnea has been employed for the first time as the main bioagent. Extracts of all the three basic components of the plant – leaves, stem and root – were explored and were found to be suitable in effecting the GNP synthesis. The electron micrographs of the synthesized GNPs revealed the presence of particles of monodispersed spherical and polydispersed triangular, hexagonal, polygonal, rod, and truncated triangular shapes in sizes ranging 3–40 and 10–100nm, respectively. The presence of gold atoms was confirmed from the EDAX and X-ray diffraction studies. The FT-IR spectral study indicated that the polysaccharides and proteins in the plant extract could have been responsible for the reduction of gold ions to GNPs and the latter’s stabilization.

The beneficial effects of vermicast on soil fertility in general, and agriculture in particular, are widely recognized, but there are no reports on the effect of storage on vermicast quality. The present study is an attempt to cover this knowledge gap as it may assist in the formulation of guidelines for packaging and storing of vermicast in a manner that preserves the cast’s fertilizer value. Vermicast generated from paper waste was packed in airtight and partially sealed bags with and without pre-drying for 24 h. Changes in several physical, chemical, and biological properties of the castings were monitored for 3 months with weekly assessments. The results reveal that the beneficial properties of vermicast were the highest when it was fresh. There was deterioration on storage, which can be minimized if the castings are contained in airtight bags after pre-drying the casts.

Multiple pool fires (MPFs) is the term used to denote pool fires which occur close enough of each other to influence each other. Even though much lesser attention has been paid to the understanding and control of MPFs, in comparison to stand-alone pool fires (SPFs), MPFs are by no means uncommon in chemical process industries. Worse, most of the MPFs–such as the ones that occurred at Buncesfield (UK) in 2005, and Jaipur (India) in 2009–are so powerful that they defy all attempts of quenching them and continue to rage till the fuel that was feeding them gets exhausted. Such fires cause enormous damage to property, besides loss of lives as occurred at Jaipur. Of the several factors that influence the destruction potential of the MPFs, pool size and separation distance between pools (S) to diameter (D) ratio (S/D) were expected to be the key factors. But no study has been done so far to analyse the effect of pool size and S/D ratio on MPFs and the present paper attempts to bridge this knowledge gap. Computational fluid dynamics (CFD) was used to model the effect of pool sizes on MPFs. The model was validated with the experimental data generated earlier by Fukuda et al. (2005). The validated code was then used to simulate the burning rate of MPFs involving pools of diameters larger than the ones used by Fukuda et al. (2005). It was observed that flame temperature, flame height, and the burning rate, all increase with an increase in the pool diameter of the participating pools in the MPFs. It was also observed that of the four S/D ratios — 0.25, 0.45, 0.66 and 1.08 — for which we have done the simulations, maximum flame height and burning rates accrues with the S/D ratio of 0.45.

When two or more pool fires burn in such close proximity of one another that they can influence each other, they are termed ‘multiple pool fires’ (MPF). The characteristics and the structure of MPFs are significantly different from that of stand-alone pool fires. Even though MPFs have known to occur fairly often in chemical process industries, much lesser work has been done towards simulation, modeling and control of MPFs as compared to stand-alone pool fires. This paper is perhaps the first-ever attempt at surveying the MPF state-of-the-art. It recounts MPF accidents and catalogs the controlled experiments that have been done to understand the mechanism and impact of MPFs. Attempts to model MPFs have been assessed and possible ways to manage MPFs have been touched upon.

Pool fires are the most common of all process industry accidents. Pool fires often trigger explosions which may result in more fires, causing huge losses of life and property. Since both the risk and the frequency of occurrence of pool fires are high, it is necessary to model the risks associated with pool fires so as to correctly predict the behavior of such fires. Among the parameters which determine the overall structure of a pool fire, the most important is turbulence. It determines the extent of interaction of various parameters, including combustion, wind velocity, and entrainment of the ambient air. Of the various approaches capable of modeling the turbulence associated with pool fires, computational fluid dynamics (CFD) has emerged as the most preferred due to its ability to enable closer approximation of the underlying physical phenomena. A review of the state of the art reveals that although various turbulence models exist for the simulation of pool fire no single study has compared the performance of various turbulence models in modeling pool fires. To cover this knowledge-gap an attempt has been made to employ CFD in the assessment of pool fires and find the turbulence model which is able to simulate pool fires most faithfully. The performance of the standard k – ɛ model, renormalization group (RNG) k – ɛ model, realizable k – ɛ model and standard k – ω model were studied for simulating the experiments conducted earlier by Chatris et al. (2001) and Casal (2013) . The results reveal that the standard k – ɛ model enabled the closest CFD simulation of the experimental results.

Background: Third generation cephalosporins are still most commonly used antibiotics empirically in our setup leading to emergence of resistance in this group. In this environment of increasing resistance, empirical use of this group of antibiotics would be a futile effort. Therefore, this study was conducted to evaluate the in vitro efficacy of fourth generation cephalosporin cefepime against multi-drug resistant isolates of Pseudomonas aeruginosa from various clinical specimens in our setup.

Quantification of spatial and temporal concentration profiles of vapor clouds resulting from accidental loss of containment of toxic and/or flammable substances is of great importance as correct prediction of spatial and temporal profiles can not only help in designing mitigation/prevention equipment such as gas detection alarms and shutdown procedures but also help decide on modifications that may help prevent any escalation of the event. The most commonly used models – SLAB ( Ermak, 1990 ), HEGADAS ( Colenbrander, 1980 ), DEGADIS ( Spicer & Havens, 1989 ), HGSYSTEM ( Witlox & McFarlane, 1994 ), PHAST ( DNV, 2007 ), ALOHA ( EPA & NOAA, 2007 ), SCIPUFF ( Sykes, Parker, Henn, & Chowdhury, 2007 ), TRACE ( SAFER Systems, 2009 ), etc. – for simulation of dense gas dispersion consider the dispersion over a flat featureless plain and are unable to consider the effect of presence of obstacles in the path of dispersing medium. In this context, computational fluid dynamics (CFD) has been recognized as a potent tool for realistic estimation of consequence of accidental loss of containment because of its ability to take into account the effect of complex terrain and obstacles present in the path of dispersing fluid. The key to a successful application of CFD in dispersion simulation lies in the accuracy with which the effect of turbulence generated due to the presence of obstacles is assessed. Hence a correct choice of the most appropriate turbulence model is crucial to a successful implementation of CFD in the modeling and simulation of dispersion of toxic and/or flammable substances. In this paper an attempt has been made to employ CFD in the assessment of heavy gas dispersion in presence of obstacles. For this purpose several turbulence models were studied for simulating the experiments conducted earlier by Health and Safety Executive, (HSE) U.K. at Thorney Island, USA ( Lees, 2005 ). From the various experiments done at that time, the findings of Trial 26 have been used by us to see which turbulence model enables the best fit of the CFD simulation with the actual findings. It is found that the realizable k – ɛ model was the most apt and enabled the closest prediction of the actual findings in terms of spatial and temporal concentration profiles. It was also able to capture the phenomenon of gravity slumping associated with dense gas dispersion.

Water quality indices (WQIs), which translate numerical values of several water quality characteristics of a sample into a single value, play a very important role in the monitoring, comparison and control of water quality. The WQIs of modern and post-modern times have been almost exclusively based on physical and chemical characteristics, and have seldom included ‘biological’ characteristics other than biochemical oxygen demand (BOD) and faecal coliforms. During the last three decades of the 20th century, indices based on bioassessment have been increasingly used in some developed countries, besides South Africa and Serbia, to complement the conventional WQIs, but the rest of the world continues to base its WQIs predominantly on physical and chemical characteristics. The serious drawbacks of this approach have been elucidated in this paper and, against that background, the state-of-the-art of biotic indices has been summarized. The paper makes a strong case for greater reliance on bioassessment-based WQIs, especially by developing countries, to strengthen the diagnostic value of the conventional WQIs.

In the original version of this article, Vipin’s name was incorrect. It is correct as reflected here. The original article has also been corrected.

Vermicomposting is a process in which earthworms are utilized to convert biodegradable organic waste into humus-like vermicast. Past work, mainly on vermicomposting of animal droppings, has shown that vermicompost is an excellent organic fertilizer and is also imbibed with pest-repellent properties. However, there is no clarity whether vermicomposts of organic wastes other than animal droppings are as plant-friendly as the manure-based vermicomposts are believed to be. It is also not clear as to whether the action of a vermicompost as a fertilizer depends on the species of plants being fertilized by it. This raises questions whether vermicomposts are beneficial (or harmful) at all levels of application or if there is a duality in their action which is a function of their rate of application. The present work is an attempt to seek answers to these questions. To that end, all hitherto published reports on the action of vermicomposts of different substrates on different species of plants have been assessed. The study reveals that, in general, vermicomposts of all animal/plant based organic wastes are highly potent fertilizers. They also possess some ability to repel plant pests. The factors that shape these properties have been assessed and the knowledge gaps that need to be bridged have been identified.

Termites are undoubtedly key soil organisms in tropical and subtropical soils. They are soil engineers in influencing the physical, chemical, and biological properties of soils and, consequently, water dynamics in tropical and subtropical ecosystems. To appreciate the effect of termites on soil, there is a need for a thorough understanding of the ecological needs and building strategies of termites and the mechanisms regulating termite diversity at local and regional scales. Termite impacts on soil properties and water dynamics can be differentiated at four different scales: (i) at the landscape scale, where termites act as heterogeneity drivers; (ii) at the soil profile scale, where termites act as soil bioturbators; (iii) at the aggregate scale, where they act as aggregate reorganizers; (iv) and last, at the clay mineral scale, where they can act as weathering agents. Last, we discuss recent literature on termite engineering published in the last 10 years in the major journals of soil science and suggest new research topics that could contribute to improved knowledge of the impact of termites on soil properties and water dynamics.

The phenomenon of superheating of liquids has fostered the development of several beneficial technologies and has the potential of revolutionizing the design and application of thermal micro-machines. But liquid superheat is also behind some of the most common and destructive accidents in the process industry. These include boiling liquid expanding vapor explosion (BLEVE), which occurs when a vessel storing pressure liquefied gas such as propane, chlorine, or ammonia is accidentally depressurized. Superheating was also responsible for the catastrophic release of methyl isocyanate in Bhopal. Besides great losses of life and inanimate assets, such accidents often cause severe environmental contamination. In nuclear industry superheated liquids pose an ever-present threat of thermo-hydraulic explosion if a leak or a break occurs in a pipeline carrying a superheated coolant. In metallurgical industries accidental contact of molten metal with another substance of much lower boiling point—such as water—can superheat the latter, causing explosion of great severity and destructive potential. Accidental dropping of water in hot oil and the resulting explosive vaporization of superheated water has been identified as the cause the largest number of household kitchen accidents. Even as knowledge of superheat limit temperature (SLT)—which is the temperature above which a liquid cannot exist at a given pressure—is central to the safe design and control of several industrial operations, reliable experimental or theoretical methods do not exist with which SLT can be determined accurately or quickly. In this paper we describe an attempt to develop a framework with which SLT of new substances can be theoretically determined with fair degree of confidence. Seven cubic equation of state (EOS) have been transformed by the application of the Maxwell's and the SLT criteria to eliminate those parameters of which correct values cannot be determined with certainty. The transformed equations have then been solved to generate SLT values. A comparison between the calculated and the observed values has been done for 75 industrial chemicals. It reveals that for a large number of chemicals the transformed Redlich–Kwong (RK) EOS is able to predict the SLT within less then 1% deviation from its experimental value. In case of the SLT of noble gases the transformed van der Waals (vdW) EOS has the best predictive ability. Only in a very few cases other EOS give a closer fit than the RK-EOS and the vdW-EOS. The ‘second best fit’ is almost always achieved with either the RK-EOS or the Twu–Redlich–Kwong (TRK) EOS.

Water quality indices are necessary for resolving lengthy, multi-parameter, water analysis reports into single digit scores. This, in turn, is essential for comparing the water quality of different sources and in monitoring the changes in the water quality of a given source as a function of time and other influencing factors. In this paper we present the computer-automated tool QUALIDEX (water QUALIty inDEX), which has been developed by us to generate and operate water quality indices. Several popular indices--such as the Oregon Water Quality Index developed in the 1970s by Oregon Department of Environmental Quality and later updated in 1995, the Aquatic Toxicity Index developed by Wepener and coworkers for protection of aquatic life at the Olifants river, Kruger National Park, South Africa, the water quality index developed by Dinius in 1987, the Overall Index of Pollution (of surface waters) developed at the National Environmental Engineering Research Institute (NEERI), and the water quality index of the Central Pollution Control Board (CPCB)--have also been added to QUALIDEX in modular form. There is also a New water quality index sub-module which enables the user to generate his or her own index and compare its performance with these well-known indices. The package is also capable of analyzing the variations in the water quality of different sites at different times. The software has been coded in Visual C++ and has been integrated with MS Access database.

Maximum credible accident analysis is one of the most widely used concepts in risk assessment of chemical process industries. Central to this concept is the aspect of ‘credibility’ of envisaged accident scenarios. However, thus far the term credibility is mostly treated qualitatively, based on the subjective judgement of the concerned analysts. This causes wide variation in the results of the studies conducted on the same industrial unit by different analysts. This paper presents an attempt to develop a criterion using which credible accident scenarios may be identified from among a large number of possibilities . The credible scenarios thus identified may then be processed for detailed consequence analysis. This would help in reducing the cost of the analysis and prevent undue emphasis on less credible scenarios at the expense of more credible ones.

An increase in the number of accidents in the process industries and the concomitant damage potential is a cause of concern in many countries. In order to control the alarming risk posed by these industries, the United States government has asked each manufacturing facility to carry out a worst-case disaster study and to develop alternatives to control this high risk. Other developed and developing countries such as Canada and India have taken similar measures. Recently Khan and Abbasi (J. Loss Prevent. Process Ind. (2001a) in press) have proposed a maximum credible accident analysis with a maximum credible accident scenario approach, which scores over a worst-case scenario approach for being realistic and reliable. In another effort, Khan and Abbasi (J. Hazard. Mater. (2001b) in press) have developed an efficient and effective algorithm for probabilistic fault tree analysis. These two approaches have been combined to yield a new methodology for a more realistic, reliable, and efficient safety evaluation and the design of risk control measures. The methodology is named SCAP: Safety, Credible Accident, Probabilistic fault tree analysis. The methodology is comprised of four steps of which the last step is a feedback loop. This paper recapitulates this methodology and demonstrates its application to ethylene oxide (EO) plants. The application of SCAP to EO plants identifies five units as risky and needing more safety measures. Further, this study recommends safety measures and demonstrates through SCAP that their implementation lower the risk to an acceptable level.

A process for the production of biogas through the anaerobic digestion (AD) of date palm tree waste (DPTW) was developed. The effects of different substrate pretreatments and operating conditions on the yield of biogas and on the chemical composition of DPTW before and after AD were studied. The best results were obtained using alkali pretreatment, with a particle size of 2 to 5 mm, a C:N ratio of 30:1, a digestion temperature of 40 °C, an initial pH of 7.0, and a volatile solids concentration of approximately 10%. The production of flammable biogas containing up to 50% methane started after about one week of operation and continued for approximately 11 weeks. The highest average biogas yield obtained was 342.2 L gas/kg of volatile solids fed to the digester. The highest maximum and average volumetric biogas production rates obtained were 674.5 and 404.4 L/m3 of digester volume per day, respectively. After digestion, there was up to a 58% reduction in the organic matter content of the substrate. Reductions in the contents of cellulose, hemicellulose, and soluble organic compounds were 68.7, 73.4, and 71.9%, respectively, while the ash and lignin contents remained mostly constant. The remaining sludge contained nutrient minerals and some organic matter which qualifies it as a potential soil fertilizer for crop production.

Chains of accidents (the domino effect) have been occurring with ever increasing frequency in chemical process industries. This is reflected in several accidents ‘J Loss Prevent Process Ind 12 (1999a) 361’; the world's worst industrial accident of the 1990s — the Vishakhpatnam disaster — also involved the domino effect ‘J Loss Prevent Process Ind 12 (1999a) 361; and Process Safety Prog 18 (1999b) 135’. Such chains of accidents have a greater propensity to cause damage than stand-alone accidents ‘Process Safety Prog 17(2) (1998a) 107; and J Loss Prevent Process Ind 12 (1999a) 361’. In order to assess the likelihood of occurrence of the domino effect and its damage potential, use of deterministic models in conjunction with probabilistic analysis is required. Recently we have proposed a systematic methodology called ‘domino effect analysis’ (DEA). A computer-automated tool, DOMIFFECT, has also been developed by us based on DEA ‘Process Safety Prog 17(2) (1998a) 107; Environment Model Software 13 (1998b) 163; and Risk assessment in chemical process industries: advanced techniques. Discovery Publishing House (1998c)’. This paper illustrates the application of DEA and DOMIFFECT to an industrial complex comprising 16 different industries. Out of 12 credible accident scenarios envisaged in three different industries — namely Madras Refineries Limited (MRL), UB Petrochemicals (UBP) and Indian Organic Chemicals Limited (IOCL), eight scenarios are likely to cause the domino effect. A further detailed analysis reveals that accidents in the storage of liquified petroleum gas and propylene and in the reflux drum units of MRL may cause domino effects. Similarly, propylene storage of UBP and monoethylene glycol storage of IOCL are also likely to cause domino effects. The impact of various chains of accidents has been forecast which reveals that in several cases the accidents may be catastrophic, harming the entire industrial complex of 16 industries. The study leads to the identification of ‘hot spots’ — units that pose the greatest risk — in turn forewarning the industries concerned and enabling them to prioritize and augment accident-prevention steps.