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Studies are presented in the context of the past attempts at finding nanocatalysts that can boost the performance of microbial fuel cells (MFCs) ─ in terms of waste treatment and energy generation. Given the great potential of biomimetically synthesized nanoparticles (BMNPs) in providing less expensive and more environmentally friendly alternatives to NPs synthesized by physical and chemical methods, as well as a near-total lack of previous work in this area, the current research was undertaken. Effect of gold and silver nanoparticles (NPs), synthesized biomimetically using five freely available weeds, was assessed as catalysts in the MFCs. In all cases, the nanoparticles were seen to enhance the coulombic efficiency (reflective of the reduction in the waste’s organic carbon load), maximum attainable power density, and overall energy yield of the MFCs by >200% relative to the uncatalyzed MFCs. Gold nanoparticles were more effective than silver nanoparticles by ≥ 20%. The results reveal that biomimetically synthesized NPs can be highly effective in reducing the operational costs as well as ecological footprints of MFCs and further work should be focused on NPs of non-precious metals.

Relative efficacy of five common weeds—of the kind that are either rooted in soil or which freely float over water—was assessed in rapid, effective and sustainable treatment of sewage at pilot plant scale in the recently developed and patented SHEFROL® bioreactors. The plants were utilized in a unit of capacity 12,000 liters/day (LPD) which, after two years of use, was enlarged to handle 40,000 LPD of sewage. It was then further expanded after an year to treat 57,000 LPD. All the five weeds, of which none has previously been tested in a pilot-scale SHEFROL, were able to foster highly efficient primary treatment (in terms of suspended and total solids) and secondary treatment (in terms of BOD and COD) to levels exceeding 85% in most cases. Additionally, the weeds also helped in achieving significant tertiary treatment. At different hydraulic retention times, and at steady state, the five weeds achieved treatment of BOD, COD, suspended solids, nitrogen, phosphorous, copper, nickel, zinc, and manganese in the ranges, 80–95, 79–91, 82–95, 61–71, 51–73, 37–43, 30–38, 39–47, and 27–35%, respectively. It all occurred in a single process step and without the use of any machine or chemical. This made the system not only simple and inexpensive to install but also to maintain. Over continuous long-term operation for four years, the system was seen to be very robust as it was able to handle wide variations in the volumes and characteristics of sewage, as well as absorb shock loads without compromising the reactor performance. The sustainability of the system can be further enhanced by upgrading it to a circular biorefinery. Energy sources in the form of volatile fatty acids (VFAs) can be extracted from the weeds removed from SHEFROL and then the weeds can be converted into organic fertilizer using high-rate vermireactors recently developed by the authors. A novel and inexpensive, yet very efficient sewage treatment system is presented. The versatility and robustness of the system has been assessed at pilot plant scale for several years. The long-term continuous studies establish the efficacy of five common weeds—not hitherto explored at pilot plant level—which can serve as the main bioagent(s) in the sewage treatment system. The system has the potential of being transformed in to a closed-loop-no-waste biorefinery [ABSTRACT FROM AUTHOR]

The wastewater ensuing from public eateries is higher in its chemical and biological oxygen demand (COD and BOD) as also its oil, grease, and protein content than sewage. For this reason such wastewater is much harder to treat; its content of fats, proteinaceous material, and xenobiotics mounting major challenges. But in most of the developing world about 80% of such wastewater is discharged untreated and the remaining is mixed with sewage going to the treatment plants. This happens due to the prohibitively high cost of treatment that is entailed if these wastewaters are to be treated by conventional activated sludge processes (ASPs) or a combination of anaerobic digestion and ASPs. The practice of allowing eatery wastewater to join sewage en route sewage treatment plants increases the load on the latter, especially due to the high fat and protein content of the former. The present work describes attempts to use the recently developed and patented SHEFROL® technology in affecting treatment of wastewater coming from a typical eatery. After establishing feasibility at bench scale, the process was tested in a case study at pilot plant scale for treating 12,000 litres/day (LPD) of wastewater being generated by the eateries situated in the campus of Pondicherry University, India. The capacity of the pilot plant was then expanded to 30,000 LPD. Despite operating the units at a very low hydraulic retention time (HRT) of 2 ± 0.5 h, due to the limitations of land availability, which translates to a rate about three times faster than a typical ASP, over 50% removal of COD and BOD, and similarly substantial removal of other pollutants was consistently achieved. Given that the SHEFROL units can be set up at a negligible cost, the findings indicate that SHEFROL technology can be used to significantly yet inexpensively pre-treat eatery wastewaters before either sending them for further treatment to conventional sewage treatment plants, higher-end SHEFROL units, or discharging them directly if neither of the other two options is available. [ABSTRACT FROM AUTHOR]

The dreaded weed ipomea (Ipomea carnea), has shown promise as a versatile phytoremediator. But I. carnea plants exude several alkaloids and phenols which are harmful to plants as well as animals. Due to this, the weed imparts as much or more toxicity to the soil as it remediates. These authors have earlier found that upon being vermicomposted by Eisenia fetida ipomea loses its toxicity and becomes a benign organic fertilizer with pest repellant attributes. These findings open up the possibility of using earthworms in those segments of land which are sought to be phytoremediated by ipomea so that the earthworms can keep converting the dead ipomea plants and the debris of live plants to fertilizer. The present work has aimed to determine whether the extent and nature of earthworm impact differs from species to species or is similar across different species. It has revealed that the action of each of the four different earthworm species deployed by the authors caused the C:N ratio of ipomea to change drastically ̶ from 28.20 to 15.95 ± 0.75, bringing the vermicomposts to the category of fertilizers fit for horticulture. The Fourier transform infrared (FTIR) spectra revealed that all the species caused a breakdown of the alkaloids and the phenolic compounds present in ipomea, resulting in the weed's detoxification. The earthworms also effected partial degradation of the lignocellulosic content of ipomea to simpler and more soil-friendly constituents like humic acids. Thermogravimetry, differential scanning calorimetry and scanning electron microscopy corroborated these findings. The influence exerted by the four species of earthworms was similarly beneficial in nature and extent. First-ever study which establishes the general applicability of earthworms in nullifying the toxic impacts caused by ipomea during its use in phytoremediation, thereby greatly enhancing ipomea's value as a phytoremediator. The studies also provide an avenue for the utilization of the otherwise worthless ipomea harvested after phytoremediation or from natural stands. [ABSTRACT FROM AUTHOR]

The efficacy of the well-known phytoremediation plant pistia (Pistia stratiotes), also called water lettuce or water cabbage, in treating sewage (greywater) was tested by its use as the main bioagent in the recently developed and patented 'sheet flow root level' (SHEFROL®) bioreactor. In contrast to previously reported systems, based on constructed wetland or stabilisation pond technologies, in which pistia needed wastewater hydraulic retention times (HRTs) of 24 h or more in enabling significant treatment of greywater, it achieved similar results in SHEFROL® several times more quickly, at the HRTs of only 4–6 h. Given that HRT directly influences reactor size, hence the system cost, the faster rate of treatment gives SHEFROL® a major economic advantage. In other ways, also, SHEFROL® appeared ideal for the use of pistia because of the reactor's ease of operation, robustness, very low requirement of energy or materials, and negligible ecological footprint. [ABSTRACT FROM AUTHOR]

This paper reports on the manufacture of ZnO nanoparticles (ZnO NPs) from Prosopis juliflora leaf extracts. Various methods of characterization were used, including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), and transmission electron microscope TEM. ZnO NPs has a hexagonal wurtzite structure with a preferred orientation of 101 planes, according to XRD. The functional groups found in ZnO NPs isolated from leaves are responsible for the FT-IR peaks that correspond to them. The morphology of the produced nanoparticles is a sphere-like form, as shown in the SEM pictures. TEM examination revealed ZnO NPs with a size of 50–55 nm. These ZnO NPs were used to remediate pollutants in paper mill effluents, and they were able to remove 86% of the organic pollutants from the sample at 0.05 mg/L dose and reduce 89% of the organic pollutants during a 5-h reflex time. Meanwhile, for the photocatalysis of paper mill effluents, it has been noted that COD was removed by 74.30%, 63.23%, and 57.96% for the first, second, and third cycles, respectively. [ABSTRACT FROM AUTHOR]

Coping Strategy Scale (CSS) is widely used to measure how individuals cope with various kind of stressors related to infertility, therefore it is necessary to translate coping strategy scale in Urdu language to make it understandable by the Pakistani population. In the present study CSS developed by Schmidt is translated for assessment of coping strategies used by infertile females. 120 infertile females of age range 20-45 were selected to participate in the present study through purposive sampling technique. CSS was translated into Urdu language using the back translation method of Brislin. The alpha reliability coefficient for subscales of CSS Urdu version ranged from 0.62 to 0.83. The CSS Urdu version would be useful for the Pakistani population to find out coping strategies used by infertile females. In future CSS will be useful for researchers working with infertility and psychosocial issues. [ABSTRACT FROM AUTHOR]

Recent studies by these authors have shown that the toxic and allalopathic weed ipomoea (Ipomoea carnea), gets transformed into benign organic fertilizer when subjected to vermicomposting. To derive benefit from this finding, it is necessary that a process should be made available for uninterrupted and efficient conversion of ipomoea into vermicompost. The present study has been done toward development of such a process, based on the concept of high-rate vermicomposting. It explores the relative ability to vermicompost ipomoea, and to reproduce in ipomoea-fed vermireactors, of successive generations of four species of earthworms — born and raised in ipomoea-fed vermireactors — in comparison to the first generation which had been raised to adulthood on cow-dung. Three epigeic species Eisenia andrei, Peryonix sansibaricus, Lumbricus rubillus, and one anecic Drawida willsi were explored for the purpose. The results, obtained over 480 days of uninterrupted reactor operation, show that the first generation of all four species of earthworms was slow to adapt to the ipomoea feed and took about 40 days to produce consistent quantities of vermicast. The second and the third generations didn't need this adaptation and each generated vermicompost at significantly faster rates than it's previous generation. Overall, the third generation of E. andrei, P. sansibaricus, L. rubellus and D. willsi produced 40, 41, 28, and 26% more vermicast, respectively, than the pioneers of the corresponding species. Similar trend was seen in fecundity as well. Each new generation produced more juveniles and cocoons than the previous generation, the increase being statistically significant at ≥ 95% confidence level. The findings reveal that earthworms can be made to adapt to ipomoea as their sole feed and the earthworm generations born and raised in ipomoea-fed vermireactors display significantly greater vermicomposting ability as well on fecundity than the earthworms which had been cultured on animal manure. [ABSTRACT FROM AUTHOR]

Even as the world has been unsuccessfully trying to dispose off the rising quantities of its municipal solid waste (MSW) and hazardous waste (HW) in a clean manner, it has been confronted with an even more complex problem—of e-waste. Only a few countries in the developed world are able to scientifically recycle or dispose the e-waste they generate. In other developed countries only a fraction of the e-waste is properly recycled, the rest is either incinerated or sent to landfills—which are solutions that cause serious secondary problems. Worse still, a sizeable portion of the e-waste generated in the developed world is exported to developing countries where it is recycled or dumped without any concern for the gross pollution that is being caused. It can be said that if the situation vis-à-vis e-waste is posing a challenge in most developed counties, it is alarmingly bad in the developing world. In an attempt to contain the e-waste problem most of the developed world and several countries in the developing world have enacted legislation to curb illegal trafficking and unlicensed recycling of e-waste. These legislations invoke the extended producer responsibility concept based on life-cycle considerations in the hope that it will provide prevention as well as cure. Innumerable non-governmental organizations and citizen's groups have also been trying to help out. So far, all these measures together have achieved only a modicum of success—that, too, only in a few regions of the developed world—but if viewed on the global scale ever bigger streams of e-waste are threatening to join the rising tides of MSW and HW in engulfing the world. The present paper assesses the state-of-the-art, bringing out how and why the e-waste problem has been defying all attempts to contain it. The paper also brings out that—much the same way as has happened with MSW and HW—the size and the complexity of the e-waste problem is increasing at much faster rate than the efficacy of our strategies to contain it. This trend is not likely to reverse soon and the only viable means to solve the problem is to drastically reduce generation of waste. [ABSTRACT FROM PUBLISHER]

Correction: Tabassum Abbasi et al., Modelling Methane and Nitrous Oxide Emissions from Rice Paddy Wetlands in India Using Artificial Neural Networks (ANNs). [Extracted from the article]

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—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. [ABSTRACT FROM AUTHOR]

Relative efficacy of five common weeds-of the kind that are either rooted in soil or which freely float over water-was assessed in rapid, effective and sustainable treatment of sewage at pilot plant scale in the recently developed and patented SHEFROL ® bioreactors. The plants were utilized in a unit of capacity 12,000 liters/day (LPD) which, after two years of use, was enlarged to handle 40,000 LPD of sewage. It was then further expanded after an year to treat 57,000 LPD. All the five weeds, of which none has previously been tested in a pilot-scale SHEFROL, were able to foster highly efficient primary treatment (in terms of suspended and total solids) and secondary treatment (in terms of BOD and COD) to levels exceeding 85% in most cases. Additionally, the weeds also helped in achieving significant tertiary treatment. At different hydraulic retention times, and at steady state, the five weeds achieved treatment of BOD, COD, suspended solids, nitrogen, phosphorous, copper, nickel, zinc, and manganese in the ranges, 80-95, 79-91, 82-95, 61-71, 51-73, 37-43, 30-38, 39-47, and 27-35%, respectively. It all occurred in a single process step and without the use of any machine or chemical. This made the system not only simple and inexpensive to install but also to maintain. Over continuous long-term operation for four years, the system was seen to be very robust as it was able to handle wide variations in the volumes and characteristics of sewage, as well as absorb shock loads without compromising the reactor performance. The sustainability of the system can be further enhanced by upgrading it to a circular biorefinery. Energy sources in the form of volatile fatty acids (VFAs) can be extracted from the weeds removed from SHEFROL and then the weeds can be converted into organic fertilizer using high-rate vermireactors recently developed by the authors.