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Water pollution is a grave risk to mankind. Water pollutants including organic toxins, dyes effluents, and heavy metals have posed great stress on water quality in recent years. This has necessitated the search for an affordable, eco-friendly, inexpensive, stable, and effective strategy for wastewater remediation. In this work, a pollyoxometallate K6[H2AlBW11O40].9H2O (KAB) was impregnated on kaolin clay to synthesize a clay-based nanocomposite KAB-K which was then evaluated for adsorptive removal of brilliant green dye (BG) from wastewater. The prepared composite was characterized by different techniques such as FTIR, SEM, and EDX analysis. The characterization results indicated the fine distribution of KAB on kaolin's surface. The adsorption studies of BG involved evaluation of optimum parameters such as time contact (30 min), quantity of adsorbent (20 mg), pH (5), temperature (40 °C), and agitation speed (125 rpm). 99.5% of BG was removed by KAB-K within 30 min. The assessment of kinetic data was performed via Langmuir, Freundlich, and Temkin models. The experimental data was found to be in good agreement with the Langmuir model (R2 > 0.9965) as compared to other models. Qmax value of KAB-K (144.92 ± 0.005 mg/g) was much higher than simple kaolin (33.22 ± 0.01 mg/g). The applicability of the pseudo-second-order kinetic model suggested that the process was predominately chemisorption. KAB-K was easier to recycle and efficiently removed up to 68.7% dye in 3 subsequent cycles. Thus rapid adsorption rate, high adsorption capacity, efficient recovery, and reusability of KAB-K endorses that the synthesized composite is an effective adsorbent for wastewater pollutants. [ABSTRACT FROM AUTHOR]

In this work, we explored the adsorptive detoxification potential of titania–bentonite clay composite for removing a cationic dye (crystal violet) from aqueous medium. Fresh clay composite sample were prepared by impregnated method, followed by spectroscopic characterization by SEM, FTIR, and EDX. After that, in batch studies dye removal were examined. The results under optimum conditions showed that this composite material has a 96% elimination capacity. Maximum removal of crystal violet was 49.26 mg/g, following Pseudo-second order kinetic model occurred at pH 8, at 125 rpm and 25 ppm initial concentration at 45 °C. Kinetics of reactions and isotherm models were investigated. Adsorption data showing the presence of monolayer adsorption were fitted using the Langmuir isotherm model. Chemisorption was shown to prevail according to Temkin isotherm criteria. Pseudo-second-order kinetics was followed in this case. For removing dye from industrial effluents, this titania–bentonite composite serves as a nonbiodegradable, low-cost, reliable, and ecologically safe adsorbent. [ABSTRACT FROM AUTHOR]

Textile industries use large amounts of water as well as dyes. These dyes containing water are then discharged into the water bodies causing a significant role in water pollution. Brilliant Green dye contributes to many harmful diseases related to the respiratory and gastrointestinal tract. In this study, Symplocos racemosa (SR) agro-waste was chemically treated with acid (SR-HCl) and base (SR-NaOH) and then used for removing Brilliant Green Dye (BGD) on the batch scale. They were characterized by SEM, EDX, FTIR, XRD, TGA and DSC. Optimized conditions were 30 °C temperature, pH 6, adsorbent dose of 0.10 g/25 ml dye solution, shaking speed of 100 revolutions per minute, initial dye concentration of 50 ppm and 35 min time for shaking adsorbent and dye solution. Adsorption data obtained were analyzed using isotherms. The experimental data was found to fit well with the Langmuir model and the maximum adsorption capacity (qmax) of BGD on the SR, SR-HCl, and SR-NaOH was revealed to be 62.90, 65.40, and 71 mg/g respectively. Kinetic data (pseudo-first-order and pseudo-second-order) were evaluated and adsorption tends to follow the pseudo-2nd-order, which indicated the chemisorption mechanism. The results revealed that Symplocos racemosa agro-waste can be considered as the potential biosorbent. [ABSTRACT FROM AUTHOR]

Salinity is assumed to be a distressing abiotic factor that mainly disrupts crop quality and yield by impairing plant cell mechanisms. Due to ion accumulation, salinity stress results in lowering growth rate and water uptake. This issue is being solved by the use of several plant growth regulators. Plant growth regulators have been proven to increase plants’ ability to withstand against stress. In this study, turnip (purple top cultivar) was subjected to four distinct levels of salt (0, 4, 8, and 12 dS/m), as well as one level of gibberellic acid, in order to assess the function of exogenously applied plant growth regulator glutamic acid (GA) (10 mM). Results revealed that salt stress slowed plant growth and decreased the amount of chlorophyll in turnip leaves. Application of salt alone resulted in a considerable decline in biochemical characteristics. However, in salt-stressed conditions, exogenous application of GA improved the antioxidant activity, chlorophyll contents and plant growth in the turnip leaves. Moreover, results depict that under salt stress vitamin C decreased; however, exogenous application of GA enhanced the Vit. C in turnip plants. Further, the uptake of salt content in turnip roots and leaves was significantly lowered by the application of GA. Additionally, under salt stress; GA dramatically controlled the quantity of phenolic compounds in turnip. [ABSTRACT FROM AUTHOR]

Onion (Allium cepa L.) is a biennial crop of high commercial value in Pakistan. Onion is considered as salt sensitive plant species. The present investigation was carried out to investigate the effect of salinity on onion and its alleviation through exogenously applied gibberellic acid (GA3; 100 mg L-1). Foliar application of GA3 (100 mg L-1) was applied on onion seedlings grown under three levels (0, 2 or 4 dS m-1) of salinity after 45 days of sowing. Results revealed that growth parameters and total soluble protein (TSP) contents declined with increase in soil salinity level. While, antioxidant enzyme activities (CAT, SOD and POD) were increased with salinity. However, exogenously applied GA3 significantly enhanced the plant growth and TSP in onion seedlings. Interestingly, CAT, SOD and POD concentration decreased with GA3 application which depicts stress alleviation in saline stressed onion plants due to GA3. It was concluded that the growth of onion could be enhanced to some extent by the application of GA3 under salinity stress. [ABSTRACT FROM AUTHOR]

A healthy crop is desirable in direct seeded vegetables to ensure good quality of the produce and is affected by a number of environmental and cultural factors. A number of seed treatments had been used to enhance the performance of seeds in several crops. Alternate cycles of dry heat and chilling (thermal hardening) is one of these seed treatments, used in cereals to invigorate the seeds, but reports about such treatments in vegetable crops are scarce. Therefore, seeds of cabbage varieties Golden Acre (GA) and Green Ball (GB), varying in their germination (%) and vigour, were exposed to different temperature (-20 and 40°C) and duration (24, 36 and 48 hrs) regimes and the effect of these treatments on seed vigour was evaluated. Different thermal hardening treatments, especially H-C 24 hrs, C-H 36 hrs, C-H-C 24 hrs and C-H-C 48 hrs, increased final germination percentage (FGP), power of germination and seedling vigour. These treatments decreased the germination spread over time in cabbage variety GB. However, such response was not observed in GA that already had high seed vigour. The impact of these better performing treatments was evaluated on germination and vigour of GA seeds under saline conditions. Interestingly, mean germination time and time taken for 50% germination was less for C-H 36 hrs and C-H-C 24 hrs treated seeds at all salinity levels. These seed treatments (H-C 24 hrs, C-H 36 hrs, C-H-C 24 hrs and C-H-C 48 hrs) improved vigour index at all salinity levels except at 200 mM NaCl concentration. Overall results depicted that C-H 36 hrs and C-H-C 24 hrs were more effective than other treatments to impart salinity tolerance and can be used as a safe tool for direct seeding of cabbage crop under normal and saline conditions. [ABSTRACT FROM AUTHOR]

Plant growth regulators (PGRs) affect various aspects of plant physiology, mainly vegetative and reproductive traits including yield and seed production. Therefore, different concentrations (0, 50, 100 & 200 ppm) of gibberellic acid (GA3) and naphthalene acetic acid (NAA), alone or in different combinations were sprayed on okra plants at 2-true leaf stage, to ascertain their impact on plant growth, pod production, seed yield and seed quality. All variables regarding vegetative and reproductive growth were significantly influenced by different concentrations of the growth regulators except number of days taken to flowering. Growth regulators were less effective when applied individually as compared to their combined use; however, performance of plants treated with individual PGR was better than the untreated plants. The number of leaves plant- 1 and plant height was higher in plants when sprayed with GA3 and NAA @ 200+100 ppm as well as with GA3 and NAA @ 200+200 ppm. The number of pods plant-1, pod length, pod fresh and dry weight, seed yield and seed quality (in terms of germination percentage and 1000-seed weight) was maximum in plants receiving foliar spray of both GA3 and NAA @ 200+200 ppm. These results signify the role of GA3 and NAA in okra pod production for fresh consumption as well as for seed yield. [ABSTRACT FROM AUTHOR]

Whole fresh button mushrooms (Agaricus bisporus) were stored in unsealed bags in two types of modified atmosphere packaging (MAP), namely, active and passive, at 4 °C. The packaging film was 0.04 mm low-density polyethylene and the gas composition of the active MAP was 12% O(2), 2.5% CO(2) and 85.5% N(2). Firmness of Mushroom showed a positive correlation with the accumulation of lignin in the tissue. On the other hand, changes of malondialdehyde content with storage time were proportional to the evolution of browning. The button mushrooms in control treatment developed severe browning at the end of the 15-day storage, while the mushrooms of both active and passive MAP treatments browned slightly. MAP treatments could not inhibit phenylalanine ammonia lyase activity; however, it can reduce the lignification process by the inhibition of peroxidase (POD) activity and the accumulation of lignin. Correlation between the cinnamyl alcohol dehydrogenase activity and lignin accumulation was not obvious. Our results suggested that an increase in the firmness of mushrooms during senescence may be a consequence of tissue lignification, a process associated with increase in POD activity. Both active and passive MAPs were useful for the conservation of tenderness and whiteness in button mushrooms.