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The beneficial application of silver nanoparticles and biostimulants to increase crop yield and quality is a long-term strategy to achieve desired agricultural productions that are resilient to various biotic and abiotic challenges. This project aimed to evaluate the individual effects of silver nanoparticles (AgNPs), Ascophyllum nodosum (SEW), and Spirulina platensis (SP) on the growth and physiological responses of Santolina chamaecyparissus. S. chamaecyparissus plants were exposed to AgNPs (20, 40, and 60 mg L−1), SWE (0.5% and 1%), and SP (1%, 2%, and 3%). The finding indicates that the light-harvesting efficiency and plant photochemical capacity are not affected by most treatments except for 60 mg L−1 AgNPs. Furthermore, the pattern of H2O2 levels in leaves was significantly higher after AgNP, SP, and SEW treatments. In parallel, total phenolic production was at least accompanied by a burst in H2O2 levels. However, higher antioxidant activity compared to the control, is shown by the higher free-DPPH-radical inhibition that goes completely smoothly with lower H2O2 levels. Thus, the results of the present study showed that biostimulants overall improved the antioxidant activity of S. chamaecyparissus and induced variable detectable amounts of phenolic compounds in response to the concentrations of each biostimulant. [ABSTRACT FROM AUTHOR]

The reduction of cement content in mortar and concrete mixtures reduces both the amount of CO2 in the environment and the cost of production. Therefore, this research utilizes Jordanian bentonite as a pozzolanic material in both mortar and concrete sample mixtures. Three types of Jordanian bentonite samples were added to the mortar and concrete mixtures 1: natural bentonite 2: heated bentonite at 250 oC, 550 oC, and 750 oC, and 3: calcium-bentonite. Then, 21 mortar mixtures were prepared. Bentonite was added to the mortar mixtures in weight proportions of 0% (reference sample), 10%, 20%, 30%, 40%, and 50% by cement weight. On the other hand, 9 concrete mixtures were prepared from natural bentonite, heated bentonite, and ca-bentonite with proportions of 0% (reference sample), 10%, and 20% partial replacement of cement weight. The tested results show that heated bentonite at 750 oC achieved close results to the control sample. Moreover, both natural bentonite and Ca-bentonite reduce concrete shrinkage. Concrete permeability was highly reduced by using bentonite, especially Catreated, where permeability was reduced by 60%. Cost and environmental analyses were conducted to evaluate the utilization of bentonite. [ABSTRACT FROM AUTHOR]

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Cadmium can enter water, soil, and food chain in amounts harmful to human health by industrial wastes. The use of intact and NaOH-treated dried algal tissues (Hydrodictyon reticulatum), a major ecosystem bio-component, for Cd removal from aqueous solutions was characterized. Cadmium biosorption was found to be dependent on solution pH, bioadsorbent dose, the interaction between pH and dose, contact time, and initial Cd concentration. The experimental results indicated that the biosorption performance of alkaline-treated algal tissues was better than that of intact tissues. The maximum biosorption capacities were 7.40 and 12.74 mg g−1for intact and alkaline-treated bioadsorbents, respectively, at optimum operating conditions. Biosorption reaches equilibrium after 24 and 240 minutes of contact, respectively, for alkaline-treated and intact bioadsorbents. Cadmium biosorption was best fitted to Langmuir isotherm model (R2≈ 0.99) and the kinetic study obeyed the pseudo-second-order kinetic model, which suggests chemisorption as the rate-limiting step in the biosorption process. Alkaline-treated algal tissues can be used as a new material of low-cost bioadsorbent for continuous flow rate treatment systems. [ABSTRACT FROM PUBLISHER]

Jordanian phosphate mine wastes (PMW) at Ruseifa City was fully characterized and tested for its PO4removal capacity by batch experiments using prepared phosphate solutions and domestic wastewater. PMW particles are positively charged with median particle size of 0.625 μm. Mineralogical and chemical analyses of PMW showed that it is mainly composed of calcite, fluorapatite, and quartz with high concentrations of calcium and phosphorous. The phosphate concentrations in PMW range from 11 to 24% expressed as P2O5. PMW as a sorbent has a very high PO4removal efficiency from wastewater and prepared solutions. PO4solutions with concentrations ranging from 5 to 5,000 mg L−1were prepared and utilized in batch experiments in the presence of PMW as a sorbent. The concentration of PO4in the solution phase and pH were the main parameters influencing the PMW sorption capacity of PO4. The PO4removal efficiency from prepared solutions was up to 99%. Moreover, Langmuir sorption model was able to describe the observed data for PO4sorption by PMW. The sorption data at PO4concentrations >50 mg L−1were highly fitted to Langmuir model. The estimated sorption maximum capacity (bmax) of PMW was 46,620 mg kg−1. On the other hand, domestic wastewater samples obtained from six Jordanian wastewater treatment plants were subjected to PO4removal by PMW, and the results showed that the PO4removal efficiency exceeded 97%. The adverse environmental impacts and human health risks associated with PMW presence are briefly discussed. [ABSTRACT FROM PUBLISHER]

A pilot grey water treatment system and collection network were designed, installed, and operated in Jordan Valley using natural filtration materials. Grey water from showers and washing sinks was collected from four houses. In order to evaluate the performance of multi-layer filter (MLF) ability to remove the pollutants from the collected grey water, the quality of treated and untreated grey water was examined and the suitability of treated grey water for irrigation was assessed. The results revealed that the efficiency removal of organic material before UV disinfection stage for BOD5, COD, and TSS was about 88.6, 83, and 92.2%, respectively. The efficiency removal rates for nutrients by MLF were a bit low as 32.5% of total phosphorous and 19.8% of total nitrogen were removed, whereas the removal efficiency of heavy metals Zn, Fe, and Ba were 94.8, 81.2, and 15.7%, respectively. The results showed that the pilot plant has efficiently reduced the coliform organisms, thermo-tolerance coli count, and Escherichia coli by more than 99.9% removal efficiency by the double-filter stage and 100% after disinfection stage. The current MLF system has the transferability potential to other locations of the developing world. [ABSTRACT FROM AUTHOR]

Environmental stresses such as low soil moisture and soil nutrient deficiency are the main causes for low productivity in arid and semi-arid regions. Soil amendments are one solution to minimize soil moisture evaporation and to improve plant nutrients uptake. The current study was carried out to examine the effect of different weathered and fresh volcanic tuff (WVT and FVT, respectively) application rates available in Jordanian market on growth, irrigation water saving and leaves mineral content of salvia Salvia officinalis. Plant growth was significantly (P ⩽ 0.01) decreased by increasing WVT/FVT application, where the maximum reductions were detected in pure WVT and FVT treatments. Leaves sodium concentration were significantly (P ⩽ 0.05) increased by 2 to 3 folds by VT application, however, other essential elements such as nitrogen, iron and manganese were decreased. The water consumption in VT amended soils was reduced from 46.5 to 67.8% and to the same extent as the total plant biomass (reductions ranged from 39 to 72%). Consequently, very marginal differences were observed between salvia plants grown in VT and pure soil treatments in water use efficiency. The high water potential of VT (i.e. can cause excess soil moisture around root system) might actually interfere with water uptake by oxygen-deprived roots and reduce plant growth. The plant growth reduction in VT amended soils might be also partially due to the slight increases in salt content and pH of growing substrates. Further research is needed to determine the effect of other types of Jordanian VT, particularly those with high zeolite and low salt and calcium carbonate content. [ABSTRACT FROM AUTHOR]