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Since the early 1990s, soil electrokinetic remediation (SEKR) has been exploited for removing organic, inorganic, and radioactive material from contaminated soil. However, the application of SEKR has been met with multiple obstacles; thus, trials have been introduced to overcome these limitations. The present study provides a comprehensive review of various modifications applied to SEKR process designs. We classified the SEKR designs in horizontal, vertical, and mixed (horizontal and vertical) types as per the movement of contaminants. SEKR is conducted via four mechanisms, namely electromigration, electroosmosis, diffusion, and electrophoresis, when a direct current electrical field is applied among two electrodes to achieve contaminant movement from one location to another. During SEKR operation, the removal rate can be adversely affected by factors such as the formation of a pH jumping zone, very high (low) pH around the cathode (anode), polarization, and reduced current efficiency with increase in time. Accordingly, in a previous research, the regular design of SEKR has been modified to address these and other limitations. Moreover, soil electrokinetic (SEK) has been used for other applications such as land restoration, geophysics, dewatering, and consolidation. This review primarily aims to provide a comprehensive summary of the major design modification made to SEK processes in the past 28 years, (1993–2020) to facilitate research on the major aspects of SEK. As per our extensive literature survey, most relevant studies focused on the horizontal SEK design. This study discusses relevant SEK studies in which process design modification is considered.

Abstract Heavy metal pollution of agricultural soil has become a major serious concern. The development of suitable control and remediation strategies for heavy metal contaminated soil has become critical. The outdoor pot experiment was conducted to investigate the effect of biochar, zeolite, and mycorrhiza on the bioavailability reduction of heavy metals and its subsequent effects on soil properties and bioaccumulation in plants as well as the growth of cowpea grown in highly polluted soil. Zeolite, biochar, mycorrhiza, zeolite with mycorrhiza, biochar with mycorrhiza, and soil without any modifications were the six treatments used. The experiment was conducted with a completely randomized design and four replications. The results indicated that the combination of biochar with mycorrhiza had the highest values of root and shoot dry weight and the lowest heavy metal concentrations in root and shoot as well as bioconcentration and translocation factors for all heavy metals. The highest significant reductions in the availability of heavy metals over the control were found with biochar with mycorrhiza, which were 59.1%, 44.3%, 38.0%, 69.7%, 77.8%, 77.2% and 73.6% for Cd, Co, Cr, Cu, Ni, Pb and Zn, respectively. The application of biochar and zeolite either alone or in combination with mycorrhiza increased significantly soil pH and EC compared to mycorrhiza treatment and untreated soil. It can be concluded that the combination of biochar and mycorrhizal inoculation has great potential as a cost-effective and environmentally technique for enhancing heavy metal immobilization, lowering heavy metal availability and plant uptake, and improving cowpea plant growth.

Abstract In this study, we investigate the dynamics of a discrete-time with predator-prey system with a Holling-III type functional response model. The center manifold theorem and bifurcation theory are used to create existence conditions for flip bifurcations and Neimark-Sacker bifurcations. Bifurcation diagrams, maximum Lyapunov exponents, and phase portraits are examples of numerical simulations that not only show the soundness of theoretical analysis but also show complicated dynamical behaviors and biological processes. From the point of view of biology, this implies that the tiny integral step size can steady the system into locally stable coexistence. Yet, the large integral step size may lead to instability in the system, producing more intricate and richer dynamics. This also means that when the intrinsic death rate of the predator is high, this leads to a chaotic growth rate of the prey. The model has bifurcation features that are similar to those seen in logistic models. In addition, there is a bidirectional Neimark-Sacker bifurcation for both prey and predator, and therefore we obtain a direct correlation in symbiosis. This means that the higher the growth rate of the prey, the greater the growth rate of the predator. Therefore, the operation of predation has increased. The opposite is also true. Finally, the OGY approach is used to control chaos in the predator and prey model. which led to a new concept which we call bifurcation phase of control chaos.

Summary: Mangroves play an integral role as a metal accumulator in tropical and subtropical marine ecosystems. Twenty-one sets of sediment samples and portions of mangroves were collected along the Saudi Arabian coast of the Red Sea to assess the accumulation and ecological risks of heavy metals. Results showed that the following mean concentrations of heavy metals in sediments: Cr (46.14 μg g−1 ± 18.48) > Cu (22.87 μg g−1 ± 13.60) > Ni (21.11 μg g−1 ± 3.2) > Pb (3.82 μg g−1 ± 2.46) > Cd (0.75 μg g−1 ± 0.87). The maximum concentrations of the studied metals were above the threshold effect level, indicating a limited impact on the respective ecosystems. The maximum concentration of Cd exceeded its toxic effect threshold, revealing a harmful risk to biota in the sediments. Based on metallo-phytoremedation, biological concentration factors were >1, suggesting that Avicennia marina can accumulate heavy metals, especially Cr and Pb. The translocation factor was above the known worldwide average. The geo-accumulation index revealed that sediments in mangrove areas ranged from moderately to heavily contaminated with Cd at Al-Haridhah and moderately contaminated at South Jeddah, Rabigh, Duba, and the wastewater treatment station near Jazan. The ecological risk index revealed that Cd could pose a relatively very high risk to the mangrove ecosystem. The present study emphasized the possibility of establishing a framework for the management of the coastal aquatic ecosystems along the Red Sea coast of Saudi Arabia. Keywords: Mangrove, Avicennia marina, Heavy metals, Pollution indices, Sediment quality, Red Sea

Safeguarding the agricultural environment from pollution is one of the most critical challenges facing the world in the context of climate change. The loss of nitrogen fertilizers through agricultural runoff or volatilization in the form of nitrate or ammonia emissions is a significant contributor to pollution. This loss also represents an economic waste that may lead to increased prices of agricultural products. Therefore, finding a solution to this problem has become imperative. An experiment was conducted on wheat plants using various rates of urea coated with slow-release materials. The study aimed to assess the impact of these fertilizers on wheat growth and yield, nutrient uptake, and nitrogen utilization efficiency (NUtE). Results demonstrated that urea fertilizers coated with slow-release materials outperformed conventional fertilizers in terms of wheat growth and yield, uptake of nitrogen, phosphorus, and potassium, as well as NUtE. The most favorable outcomes were achieved using urea-formaldehyde, urea-humic, and urea-biochar fertilizers at 100% of the recommended nitrogen application rate. This resulted in economically viable grain production with high fertilizer efficiency. Based on these findings, we recommend applying either urea-formaldehyde or urea-humic at a rate of 107 kg N ha−1 to produce wheat grain and straw with enhanced NUtE. This approach can help reduce environmental pollution caused by nitrogen losses. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Plant Protection & Pathology is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Plant Protection & Pathology is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)