Novel S-N/WO3: Optimization of photocatalytic performance of WO3 by simultaneous existence of S and N in WO3 against MB dye.

In this work, pure and S-N/WO3 (1%-7%) nanoparticles (NPs) have been developed for the degradation of MB dye. Optical properties, vibrational analysis, morphology, structural analysis, and photocatalytic activity of the samples have been evaluated using a variety of characterization techniques, including UV-vis, PL, FTIR, SEM, and x-ray diffraction (XRD). The XRD patterns showed that the stability of the orthorhombic phase of WO3 was affected by the concentrations of S and N. In SEM, nanospheres with an average size of 80 nm of NPs have been observed. The PL results showed that the e-, h+ recombination rate for the S-N7%/WO3 sample was the lowest. The degradation of MB dye has also been investigated in order to investigate the photocatalytic performance. Remarkably, S-N7%/WO3 shows the best results, with a maximum degradation of 90% in 120 min. The stability of the improved catalyst was tested using recycling and trapping studies. S-N7%/WO3 catalyst's exceptional photocatalytic activity highlights its potential use in wastewater treatment. This study will be helpful for manufacturing innovation.

Facile green synthesis of novel tantalum doped tungsten trioxide for photocatalytic degradation: Correlation with COMSOL simulation.

The facilegreen synthesis techniqueis becoming more and more important, and it has been proposed as a potential substitute for chemical techniques. The current study describes a low-cost, environmentally friendly method for producing tungsten trioxide (WO3) and tantalum (Ta) doped WO3nanoparticles that uses 15 % (w/v) Azadirachta indica (Neem) leaf extract and different concentrations of Ta dopant (1 to 5 %) due to its well-matched ionic radius with WO3. Various techniques FESEM, TEM, EDX, BET, UV-Vis and PL, XRD, and FTIR were used to illustrate the morphological, elemental, optical, structural, and vibrational analysis of the synthesized nanoparticles respectively. Interestingly, the band gap was significantly reduced to 1.88 eV by the addition of a dopant element. For 3 % Ta/WO3, the average particle size was also reduced to 31.6 nm. The synthesized WO3nanoparticles employed in the current study have been used for photocatalytic activitypurposes. Methylene blue (MB), one of the principal water pollutants, was degraded more quickly by the synthesized Ta/WO3nanoparticles when exposed to UV radiation. Among them, 3 % Ta/WO3 gives significantly higher photodegradation 89 % attributed to the Burstein-Moss effect. The significant output of optimized nano-photocatalyst has been observed from the trapping experiment and reusability test. Furthermore, Zeta potential and TOC analysis have been taken to check the stability and mineralization performance. Additionally, the results of the simulation that was carried out using the finite element analysis approach in the RF module of COMSOL Multiphysics 5.3a are quite similar to the experimental findings. This simulation method made it easier for readers to understand the numerous aspects of the photocatalytic process that has been discussed here.

Comparative photocatalytic study of visible light driven BiVO4, Cu2O, and Cu2O/BiVO4 nanocomposite for degradation of antibiotic for wastewater treatment.

Semiconductor-based photocatalysts have become increasingly used in the removal of pollutants from wastewater, especially antibiotics. A series of composite-based cuprous oxide and bismuth vanadate (Cu2O/BiVO4) composite-based photocatalysts were synthesized by using the chemical method. The structure of the Cu2O/BiVO4 composite was verified by using x-ray diffraction, scanning electron microscopy, photoluminescence, Fourier transform infrared spectroscopy, and UV-visible spectra. The degradation of methylene blue (MB) and tetracycline (TC) was investigated to check the photocatalytic activity of the Cu2O/BiVO4 composite series. The quantity of Cu2O was varied from 1% to 7% by weight to prepare the series of Cu2O/BiVO4 composites. The analysis of results verified that 5% Cu2O/BiVO4 exhibits an outstanding photocatalytic activity as compared to 1%, 3%, and 7% Cu2O/BiVO4, pure Cu2O, and pure BiVO4 under visible light irradiation. The optimum value of photocatalytic degradation achieved with 5% Cu2O/BiVO4 was 97% for MB dye and 95% for TC in 120 min, which is greater than the photocatalytic degradation of pure BiVO4 (MB 45% and TC 72%), pure Cu2O (MB 57% and TC 80%), 1% Cu2O/BiVO4 (MB 72% and TC 85%), 3% Cu2O/BiVO4 (MB 83% and TC 88%), and 7% Cu2O/BiVO4 (MB 87% and TC 91%). The stability and reusability of Cu2O/BiVO4 were also investigated. To check the major role of trapping in degradation, a trapping experiment was also performed by using three trapping agents: BQ, EDTA, and tBuOH. The results showed that Cu2O/BiVO4 exhibits an improved photocatalytic activity in the degradation of antibiotics in polluted water because the recombination rate of the electron-hole pair decreased and the surface area increased, which increased the active sites for redox reactions. Such a photocatalytic composite with high efficiency has various applications, such as energy production, environmental remediation, and water remediation.

Facile hydrothermal synthesis of BiVO4 nanomaterials for degradation of industrial waste.

Bismuth Vanadate (BiVO4) has been synthesized using simple hydrothermal technique while varying the pH of concentrated H2SO4. With the increase of pH values (from 06 to 10), the morphology of the synthesized material tuned in the form of nano-spheres and cubes in the range from 50 to 60 nm. The lateral affect tuned the bandgap of BiVO4 from 2.47 eV to 2.50 eV which is significant in the context of present study. It is worth mentioning that desirous bandgap corresponds to the visible spectrum of the solar light being abundantly available and finds many applications in real life. The synthesized nanomaterial BiVO4 has been characterized through UV-Vis spectroscopy, X-ray diffraction, Scanning electron microscope and energy-dispersive X-ray (EDX) spectroscopy. The synthesized BiVO4 has been tested as photocatalyst for degradation of industrial pollutant from Leather Field Industry. Said catalyst (BiVO4) successfully degraded the industrial pollutant after 3 h under solar light irradiation. Therefore, the BiVO4 can be regarded as potential photocatalyst for degradation of industrial waste which is highly needed.

Nanocidal Effect of Rice Husk-Based Silver Nanoparticles on Antioxidant Enzymes of Aphid.

Green synthesis of nanoparticles using plant-based extracts is momentously used in different fields of science because of their environment-friendly nature and cost-effectiveness. In the present study, silver nanoparticles were synthesized by using rice husk (non-toxic agricultural by-product) to determine their efficacy against aphid's (Sitobion avanae) mortality and antioxidant enzymes. UV-VIS spectroscopy of synthesized nanoparticles showed the maximum absorption peak at 440 nm, FTIR exhibited different peaks, and SEM confirmed the roughly spherical shape and 70-80 nm size of silver nanoparticles. Aphids were reared on wheat seedlings in the laboratory at 20-25 °C and 16:8 (light:dark) photoperiod. Insecticidal bioassays were conducted on aphids at three different concentrations (200 ppm, 400 ppm, 600 ppm) of nanoparticles for 2 days. Results showed the highest mortality of aphids being 93.3% at 600 ppm nanoparticle concentration after 2 days while the lowest mortality was observed at 200 ppm. Furthermore, the effect of silver nanoparticles on antioxidant enzymes was studied. Results of enzyme assays revealed that enzyme activities of catalase and glutathione-s-transferase increased in response to increased nanoparticle concentration. The current findings suggested that silver nanoparticles have probation for replacing commercially available insecticides for combating pests.

The water striders of Pakistan (Hemiptera: Heteroptera: Gerridae): new records from Punjab and first checklist for the country.

This study was conducted to explore the gerrid fauna of the Industrial Triangle of Punjab (Pakistan). Five species were collected during this study, of which three are recorded for the first time for Pakistan: Metrocoris communis (Distant, 1910), Heterobates bilobatus (Esaki, 1927), and Naboandelus bergevini popovi Brown, 1951. A sixth species was added from Punjab (Pakistan) from museum material, and two others from Indian Kashmir. For two taxa, H. bilobatus and N. bergevini popovi, the new records extended their known range. Further, Rheumatobates maculata Khatoon Ali, 1978 is proposed as a junior synonym of Metrocoris communis (Distant, 1910) and Gerris lacustris (Linnaeus, 1758) is excluded from the Pakistani fauna. The first provisional checklist for the Gerridae of Pakistan is presented and the gerrid fauna of neighboring countries to Pakistan is discussed.

A cross sectional survey of knowledge, attitude and practices related to the use of insecticides among farmers in industrial triangle of Punjab, Pakistan.

Pesticides in Pakistan are abundantly utilized for pest control in agriculture sector. The over and unsafe use of insecticides plus poor handling leads to the development of resistance, outbreak of secondary pests and hazardous impact on environment. The present study was aimed to access the current knowledge, attitude and common practices of farmers about the use of insecticides against pest in industrial triangle of Province Punjab, Pakistan. This study was conducted during October 2019 to February 2020. In this study farmers (n = 300) took part from three localities of Province Punjab (Gujrat, Gujranwala and Sialkot). Farmers were interviewed using a questionnaire to collect data about the knowledge of pest control by use of chemical method, biological method and combination of both to eradicate the pests. The result shows almost all (93%) farmers were male and they did not know about the insecticides mode of action and its chemical composition. They do not have any knowledge about the biological control of pests and did not get any assistance or help from Agriculture Extension Officer. They even did not properly dispose off the empty containers of insecticides. Statistical analysis reveals that lack of education and awareness about biological control of pest depicts development of resistance and outbreak of secondary pest including health hazards and environmental pollution. Poor understanding about pests, abundant use of insecticides, incorrect perception about application of insecticides and negligence regarding biological control shows that there is need to initiate public awareness programs to ensure the application of integrated pest management (IPM) and sustainable agriculture.

Efficient biosensing through 1D silver nanostructured devices using plasmonic effect.

The current work explores the excitation of surface plasmon polaritons (SPPs) on a one dimensional (1D) silver nano-grating device, simulated on glass substrate, which can sense a very small change in the refractive index of an analyte adjacent to it. The most recent modeling technique finite element analysis is applied in this work by using a COMSOL RF module. The models of 1D grating devices of different slit widths with fixed periodicity and film thickness are simulated. The data is collected and then used to study higher refractive index unit per nanometer (RIU/nm) as well as the effect of the widths of the slits on the RIU. A number of investigations are done by the simulated data, like a dip in the transmission spectra of p-polarized light. This dip is due to SPP resonance with the variation of slit width. Furthermore, the most fascinating part of the research is the COMSOL modeling that provides an opportunity to look into factors affecting higher RIU/nm, while visualizing the cross-sectional view of the grating device and strong electric field enhancement at the surface of the metallic device. When the slit width is almost equal to half of the periodicity of the grating device, SPP resonance increases and it is at maximum for the slit width equal to two-thirds of the periodicity, because the coupling efficiency is at maximum.

Corrigendum to "Natural Treatment Systems as Sustainable Ecotechnologies for the Developing Countries".

[This corrects the article DOI: 10.1155/2013/796373.].

Evaluating Insects as Bioindicators of Heavy Metal Contamination and Accumulation near Industrial Area of Gujrat, Pakistan.

To study the accumulation and contamination of heavy metals (i.e., Cd, Cr, Cu, Ni, and Zn) in soil, air, and water, few insect species were assayed as ecological indicators. Study area comes under industrial zone of district Gujrat of Punjab, Pakistan. Insects used as bioindicators included a libellulid dragonfly (Crocothemis servilia), an acridid grasshopper (Oxya hyla hyla), and a nymphalid butterfly (Danaus chrysippus) near industrial zone of Gujrat. Accumulation of Cd was highest in insect species followed by Cu, Cr, Zn, and Ni at p < 0.05. Hierarchical cluster analysis (HACA) was carried out to study metal accumulation level in all insects. Correlation and regression analysis confirmed HACA observations and declared concentration of heavy metals above permissible limits. Metal concentrations in insects were significantly higher near industries and nallahs in Gujrat and relatively higher concentrations of metals were found in Orthoptera than Odonata and Lepidoptera. The total metal concentrations in insects were pointed significantly higher at sites S3 (Mid of HalsiNala), S9 (End of HalsiNala), and S1 (Start of HalsiNala), whereas lowest value was detected at site S6 (Kalra Khasa) located far from industrial area. HACA indicates that these insect groups are potential indicators of metal contamination and can be used in biomonitoring.

Natural treatment systems as sustainable ecotechnologies for the developing countries.

The purpose of natural treatment systems is the re-establishment of disturbed ecosystems and their sustainability for benefits to human and nature. The working of natural treatment systems on ecological principles and their sustainability in terms of low cost, low energy consumption, and low mechanical technology is highly desirable. The current review presents pros and cons of the natural treatment systems, their performance, and recent developments to use them in the treatment of various types of wastewaters. Fast population growth and economic pressure in some developing countries compel the implementation of principles of natural treatment to protect natural environment. The employment of these principles for waste treatment not only helps in environmental cleanup but also conserves biological communities. The systems particularly suit developing countries of the world. We reviewed information on constructed wetlands, vermicomposting, role of mangroves, land treatment systems, soil-aquifer treatment, and finally aquatic systems for waste treatment. Economic cost and energy requirements to operate various kinds of natural treatment systems were also reviewed.

OsNPR1 negatively regulates herbivore-induced JA and ethylene signaling and plant resistance to a chewing herbivore in rice.

NPR1 (a non-expressor of pathogenesis-related genes1) has been reported to play an important role in plant defense by regulating signaling pathways. However, little to nothing is known about its function in herbivore-induced defense in monocot plants. Here, using suppressive substrate hybridization, we identified a NPR1 gene from rice, OsNPR1, and found that its expression levels were upregulated in response to infestation by the rice striped stem borer (SSB) Chilo suppressalis and rice leaf folder (LF) Cnaphalocrocis medinalis, and to mechanical wounding and treatment with jasmonic acid (JA) and salicylic acid (SA). Moreover, mechanical wounding induced the expression of OsNPR1 quickly, whereas herbivore infestation induced the gene more slowly. The antisense expression of OsNPR1 (as-npr1), which reduced the expression of the gene by 50%, increased elicited levels of JA and ethylene (ET) as well as of expression of a lipoxygenase gene OsHI-LOX and an ACC synthase gene OsACS2. The enhanced JA and ET signaling in as-npr1 plants increased the levels of herbivore-induced trypsin proteinase inhibitors (TrypPIs) and volatiles, and reduced the performance of SSB. Our results suggest that OsNPR1 is an early responding gene in herbivore-induced defense and that plants can use it to activate a specific and appropriate defense response against invaders by modulating signaling pathways.

Damselflies (Zygoptera: Odonata) of Pakistan: part 1.

The present study is an effort to document bio-geographical distribution for Zygoptera of Pakistan. Damselflies were collected throughout the country and territory of Azad Jammu and Kashmir during 2004-2009. A total of 2692 specimens were collected yielding 9 families, 21 genera, and 48 species and subspecies. Three of these species, Libellago lineata lineata (Burmeister), Elattoneura atkinsoni (Selys), and Elattoneura souteri (Fraser), are recorded for the first time from Pakistan. Distribution, habitats, previous records, and Zoogeographic affiliation for all collected taxa are discussed. Help was also taken from published literature on Zygoptera of Pakistan, and specimens housed at National Insect Museum were also studied. In total, 53 species are accounted for providing an updated record for all modern taxa of damselfly fauna of Pakistan.