Toxicities, kinetics and degradation pathways investigation of ciprofloxacin degradation using iron-mediated H\u3csub\u3e2\u3c/sub\u3eO\u3csub\u3e2\u3c/sub\u3e based advanced oxidation processes

© 2018 Institution of Chemical Engineers Ciprofloxacin (CIP) is a widespread emerging water pollutant and thus its removal from aquatic environment is vital. The use of Fe3+/H2O2 and Fe2+/H2O2 resulted in 38 and 64% removal of CIP (8.0 ppm), respectively, within 80 min reaction time (pH 5.8, [H2O2]0 = 80 ppm, and [iron]0 = 20 ppm). Low pH, high temperature, high dose of H2O2 and Fe2+, and low CIP concentration facilitated removal of CIP. The radical scavenger studies proved in situ generated [rad]OH to be involved primarily in the removal of CIP. The effect of temperature was used to estimate enthalpy and activation energies of the removal of CIP. At 800 min reaction time, the Fe2+/H2O2 resulted in 54% mineralization of CIP using 16.0 ppm [CIP]0, 320.0 ppm [H2O2]0, and 40.0 ppm [Fe2+]0. The potential degradation pathways of CIP established from the degradation of CIP by [rad]OH and products evolved was found to be initiated at C6 through the loss of fluoride ion. The acute and chronic toxicities of CIP and its degradation products were estimated with the final product found to be non-toxic. The results suggest that Fe2+/H2O2-mediated AOPs have high potential for degradation as well as toxicity elimination of CIP and its degradation products

Straw Incorporation in Contaminated Soil Enhances Drought Tolerance but Simultaneously Increases the Accumulation of Heavy Metals in Rice

Heavy metals (HMs) and drought stress are worldwide issues of concern because of their adverse effects on the growth and productivity of rice. Straw burning causes air pollution via greenhouse gas (GHG) emissions and it requires sustainable management. The introduction of HMs into the food chain poses a major health risk to humans. In this regard, straw incorporation into the soil could reduce air pollution and drought stress. However, its simultaneous impact on HMs’ uptake and drought stress tolerance in crops is unknown. Therefore, the present study aimed to investigate the impact of rice straw incorporation in soil on HMs (Cd, Cu, Pb, and Fe) availability, accumulation, and drought stress tolerance in rice (Oryza sativa L.) grown in pots under glasshouse conditions. The soil samples were collected from a non-contaminated agricultural field (control) and the contaminated field, irrigated with industrial effluent and treated with straw. Straw (1% w/w) was mixed in soils and control plants without straw application were grown under both contaminated and normal soil conditions. The results showed that straw incorporation in soils significantly enhanced the accumulation of HMs in rice grain and other vegetative parts of rice as compared to control. Moreover, straw application harmed chlorophyll and carotenoids. Straw application significantly increased proline in leaves (274.0 µg mL−1) as compared to the control (166.8 µg mL−1). Relative water contents were higher in straw-treated plants, thereby increasing drought stress tolerance. Straw application increased the accumulation of HMs and consequently reduced the biomass of the plant. In conclusion, straw incorporation enhanced drought stress tolerance but simultaneously elevated the accumulation of HMs under contaminated soil in Oryza sativa L

Secure Framework Enhancing AES Algorithm in Cloud Computing

The tremendous growth of computational clouds has attracted and enabled intensive computation on resource-constrained client devices. Predominantly, smart mobiles are enabled to deploy data and computational intensive applications by leveraging on the demand service model of remote data centres. However, outsourcing personal and confidential data to the remote data servers is challenging for the reason of new issues involved in data privacy and security. Therefore, the traditional advanced encryption standard (AES) algorithm needs to be enhanced in order to cope with the emerging security threats in the cloud environment. This research presents a framework with key features including enhanced security and owner’s data privacy. It modifies the 128 AES algorithm to increase the speed of the encryption process, 1000 blocks per second, by the double round key feature. However, traditionally, there is a single round key with 800 blocks per second. The proposed algorithm involves less power consumption, better load balancing, and enhanced trust and resource management on the network. The proposed framework includes deployment of AES with 16, 32, 64, and 128 plain text bytes. Simulation results are visualized in a way that depicts suitability of the algorithm while achieving particular quality attributes. Results show that the proposed framework minimizes energy consumption by 14.43%, network usage by 11.53%, and delay by 15.67%. Hence, the proposed framework enhances security, minimizes resource utilization, and reduces delay while deploying services of computational clouds

Biochar Reduced Cadmium Uptake and Enhanced Wheat Productivity in Alkaline Contaminated Soil

Cadmium (Cd) is a toxic heavy metal present in the environment which causes severe environmental, nutritional, and ecological losses. A pot incubation study was conducted to assess the role of biochar derived from various organic feedstock's [poultry manure (PM), farmyard manure (FYM) and sugarcane press mud (PS)] and dosages (0, 2.5 and 5 g kg(-1) soil of each) to immobilize Cd (5 mg kg(-1)) in Cd polluted soil. Moreover, impact of applied biochar to reduce the bioavailability of Cd in wheat tissues and to improve wheat growth and yield was also observed. Among all type of applied biochar, application of farmyard manure (FYM) derived biochar improved tillers population (77%), chlorophyll SPAD value (74%), plant height (69), grains yield (77%) and biological yield (82%) of wheat. Moreover, FYM derived biochar lowered the Cd uptake and its translocation from roots (71-92%) shoots (82-92%), and grains (90-96%) as compared with control. While in Cd-contaminated soil without biochar application, the Cd concentration in roots, shoots and grains were 1.4, 1.14 and 0.9 mg kg(-1) of dry matter, respectively. Overall, FYM derived biochar, applied at 5 g kg(-1) of soil performed better in reducing the Cd toxicities in soil (0.12 mg kg(-1)) and wheat roots (0.13 mg kg(-1)), shoots (0.1 mg kg(-1) ) and grains (0.03 mg kg(-1)) along with higher wheat yield in Cd polluted soil. In conclusion, FYM derived biochar has the potential to remediate Cd toxicities in alkaline polluted soil. (C) 2020 Friends Science Publisher

Vanadium toxicity in chickpea (Cicer arietinum L.) grown in red soil: Effects on cell death, ROS and antioxidative systems

The agricultural soil contaminated with heavy metals induces toxic effects on plant growth. The present study was conducted to evaluate the effects of vanadium (V) on growth, H2O2 and enzyme activities, cell death, ion leakage, and at which concentration; V induces the toxic effects in chickpea plants grown in red soil. The obtained results indicated that the biomass (fresh and dry) and lengths of roots and shoots were significantly decreased by V application, and roots accumulated more V than shoots. The enzyme activities (SOD, CAT, and POD) and ion leakage were increased linearly with increasing V concentrations. However, the protein contents, and tolerance indices were significantly declined with the increasing levels of V. The results about the cell death indicated that the cell viability was badly damaged when plants were exposed to higher V, and induction of H2O2 might be involved in this cell death. In conclusion, all the applied V levels affected the enzymatic activities, and induced the cell death of chickpea plants. Furthermore, our results also confirmed that vanadium 130 mg kg(-1) induced detrimental effects on chickpea plants. Additional investigation is needed to clarify the mechanistic explanations of V toxicity at the molecular level and gene expression involved in plant cell death

Promotion of Growth and Physiological Characteristics in Water-Stressed Triticum aestivum in Relation to Foliar-Application of Salicylic Acid

The present work reports the assessment of the effectiveness of a foliar-spray of salicylic acid (SA) on growth attributes, biochemical characteristics, antioxidant activities and osmolytes accumulation in wheat grown under control (100% field capacity) and water stressed (60% field capacity) conditions. The total available water (TAW), calculated for a rooting depth of 1.65 m was 8.45 inches and readily available water (RAW), considering a depletion factor of 0.55, was 4.65 inches. The water contents corresponding to 100 and 60% field capacity were 5.70 and 1.66 inches, respectively. For this purpose, seeds of two wheat cultivars (Fsd-2008 and S-24) were grown in pots subjected to water stress. Water stress at 60% field capacity markedly reduced the growth attributes, photosynthetic pigments, total soluble proteins (TSP) and total phenolic contents (TPC) compared with control. However, cv. Fsd-2008 was recorded as strongly drought-tolerant and performed better compared to cv. S-24, which was moderately drought tolerant. However, water stress enhanced the contents of malondialdehyde (MDA), hydrogen peroxide (H2O2) and membrane electrolyte leakage (EL) and modulated the activities of antioxidant enzymes (superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), as well as accumulation of ascorbic acid (AsA), proline (Pro) and glycine betaine (GB) contents. Foliar-spray with salicylic acid (SA; 0, 3 mM and 6 mM) effectively mitigated the adverse effects of water stress on both cultivars. SA application at 6 mM enhanced the shoot and root length, as well as their fresh and dry weights, and improved photosynthetic pigments. SA foliage application further enhanced the activities of antioxidant enzymes (SOD, POD, and CAT) and nonenzymatic antioxidants such as ascorbic acid and phenolics contents. However, foliar-spray of SA reduced MDA, H2O2 and membrane permeability in both cultivars under stress conditions. The results of the present study suggest that foliar-spray of salicylic acid was effective in increasing the tolerance of wheat plants under drought stress in terms of growth attributes, antioxidant defense mechanisms, accumulation of osmolytes, and by reducing membrane lipid peroxidation

Immobilization of Pb and Cu by organic and inorganic amendments in contaminated soil

Soil contamination with heavy metals has become a global environmental-health concern. A series of greenhouse experiments were conducted to investigate the effects of rice straw, rice straw derived biochar (BC), multi-walled carbon nanotubes, and single superphosphate (SSP) on immobilization of Pb and Cu via sequential extraction of BCR, total characteristics leaching procedure (TCLP), and metals phytoavailability to rapeseed in Pb and Cu spiked soil. Moreover, the residual effect of applied soil amendments on growth and uptake of Pb and Cu in tomato was also investigated in the metals spiked soil. In results, the addition of BC to Pb and Cu spiked soil proved the most effective amendment in modifying the distribution pattern of Pb and Cu from acid-soluble (less bioavailable) to residual fraction (non-toxic), thereby improving the geochemical stability of contaminated soil. The application of BC (6% w/w) reduced the uptake of Pb and Cu in shoot and root by 46 and 36%, and 77 and 58%, respectively. While investigating the residual impact in tomato, the uptake was decreased by 36 and 66% for Pb and 29 and 61% for Cu in shoot and root samples, respectively. With the application of BC (6% w/w), the concentrations of Pb and Cu in the shoot portion of tomato were below the permissible limits as set by the world health organization. The application of SSP was more effective in reducing TCLP-Pb to 0.2 mg L-1 in metals spiked soil compared to the other amendments. However, the bioavailability of Cu was increased with increasing SSP addition. In conclusion, the application of BC was more effective in reducing Pb and Cu phytoavailability through immobilization in contaminated soil compared to the other organic and inorganic amendments

Foliar Application of Gibberellin Alleviates Adverse Impacts of Drought Stress and Improves Growth, Physiological and Biochemical Attributes of Canola (Brassica napus L.)

Under the current climate change scenario, water stress is one of the key factors that reduce the production of crops. Gibberellic acid (GA3) is an efficient endogenous plant hormone that shows a vital role in plant growth and development. Production of canola (Brassica napus L.) and its oil contents are severely affected under drought stress. The present study was conducted to investigate the potential of GA3 in alleviating drought stress in canola. Three levels of GA3 (G0 = 0 mg L−1, G1 = 100 mg L−1, and G2 = 150 mg L−1) as foliar applications were applied under two drought-stress conditions (D1 for three days of drought stress and D2 for six days of drought stress) on two canola varieties (Punjab canola and Faisal canola). Irrigation was applied after 3 weeks of germination, while foliar application of GA3 was done at intervals of 4 and 5 weeks after germination. When comparing the output of all the GA3 treatments, it was noticed that in G0 = 0 mg L−1 (control plants), water-stress conditions markedly reduced plant production and seed oil contents but increased protein and linoleic acid. With the application of G2 = 150 mg L−1, the maximum values of plant height (90.83 cm), no. of siliqua plant−1 (15.50), seed siliqua−1 (15.55), siliqua length (5.08 cm), relative water contents (77.60%), yield plant−1 (0.46 g), chlorophyll a (0.62), carotenoid contents (39.52), and oleic acid contents (60.20) were recorded under drought stress. Based on these results, it is concluded that the adverse effect of drought stress on different yield parameters of canola could be ameliorated by the exogenous application of GA3 through foliar application at a dose of 150 mg L–1. Moreover, the same treatment improves the quality parameters, i.e., the oleic acid contents of the oil, obtained from the canola

Vanadium toxicity in chickpea (Cicer arietinum L.) grown in red soil: Effects on cell death, ROS and antioxidative systems

The agricultural soil contaminated with heavy metals induces toxic effects on plant growth. The present study was conducted to evaluate the effects of vanadium (V) on growth, H2O2 and enzyme activities, cell death, ion leakage, and at which concentration; V induces the toxic effects in chickpea plants grown in red soil. The obtained results indicated that the biomass (fresh and dry) and lengths of roots and shoots were significantly decreased by V application, and roots accumulated more V than shoots. The enzyme activities (SOD, CAT, and POD) and ion leakage were increased linearly with increasing V concentrations. However, the protein contents, and tolerance indices were significantly declined with the increasing levels of V. The results about the cell death indicated that the cell viability was badly damaged when plants were exposed to higher V, and induction of H2O2 might be involved in this cell death. In conclusion, all the applied V levels affected the enzymatic activities, and induced the cell death of chickpea plants. Furthermore, our results also confirmed that vanadium 130 mg kg(-1) induced detrimental effects on chickpea plants. Additional investigation is needed to clarify the mechanistic explanations of V toxicity at the molecular level and gene expression involved in plant cell death