Mojave yucca (Yucca schidigera) is widely grown in the deserts. This herb is commercially used because it is rich in saponins and phenolic compounds with antioxidant effect. Y. schidigera or its derivatives are included as nontoxic food supplements, in cosmetics, and in the pharmaceutical industry. Saponins originated from Y. schidigera have anti-inflammatory, antioxidant, immunostimulatory, growth promoter, hypocholesterolemic, and hypoglycemic effects. To date, the key role of Y. schidigera or its products in animal nutrition is to reduce the ammonia content in the atmosphere and fecal odor in poultry excreta. Mitigating ammonia by using this plant could be achieved by the modification of gut microbiota, enhancement in digestion, and absorption of nutrients, leading to a better growth and production performance of animals and poultry. Various methods were applied to mitigate the emission of odor from the litter by different strategies including biofilters, litter treatments, air scrubbers, neutralizing agents, windbreak walls, etc., but these techniques are expensive. This article provides a new insight to scientists and poultry breeders to use Y. schidigera plant or its products as inexpensive and safe sources of a feed supplement to overcome the ammonia and fecal odor problems, as well as reduce environmental pollution in poultry houses.

Microbial fuel cells (MFCs) have gained increasing attention as an effective pathway for wastewater treatment and electrical energy recovery. In this study, the pollutant removal, N₂O production, and electricity generation at different temperatures (25–45 °C) in a dual-chamber MFC were investigated. The optimal temperature for pollutant removal and electricity generation was 35 °C. The results showed that maximal removal efficiencies of chemical oxygen demand (COD), ammonium (NH₄⁺), and total nitrogen (TN) were 73.98 ± 0.92%, 99.24 ± 0.85%, and 8.28 ± 0.45%, respectively. The maximum of nitrous oxide (N₂O) was 4.27 ± 0.11 mg L⁻¹ at 35 °C. Meanwhile, the maximum of power density, current density, and coulombic efficiency (CE) were 0.54 W m⁻³, 6.51 A m⁻³, and 8.12 ± 0.04%, respectively. The results indicate that MFC is a promising technology for simultaneous pollutant removal and electricity generation in temperate regions. Moreover, microbial community analysis suggested that the dominant reaction in the cathode may include aerobic nitrification, autotrophic denitrification, heterotrophic denitrification (aerobic and anoxic), reduction of oxygen, and nitrogen fixation.

This research investigated the enzyme-catalyzed oxidative polymerization and precipitation/co-precipitation of the anilino compounds, p-cresidine (2-methoxy-5-methylaniline), and 4,4′-oxydianiline (ODA) suspected to be human carcinogens by the U.S. Environmental Protection Agency, as a means of treating industrial wastewater containing these pollutants. p-Cresidine is a synthetic chemical intermediate for azo dyes and pigments in the food and textile industries whereas ODA is used in the production of polyimide and poly(ester)imide resins in North America. A potentially inexpensive enzyme extracted from the soybean seed coat, soybean peroxidase (SBP), which is widely available from the agricultural commodity, was used to treat both these compounds. The optimum operating conditions such as pH, hydrogen peroxide-to-substrate concentration ratio, and the minimum SBP concentration required to achieve at least 95% SBP-catalyzed conversion of these pollutants in synthetic wastewaters were determined. Electrospray ionization mass spectrometry, employed for preliminary product determination after enzymatic conversion of the substrates, revealed the formation of azo dimers in the precipitates. A pro-forma cost analysis is presented showing the feasibility of commercialization of enzymatic treatment as an alternative, or as an adjunct, to conventional treatment methods.

Chlorinated solvents generally enter the subsurface as dense nonaqueous phase liquids (DNAPL) and accumulation mostly occurs in aquifers as pool-dominated zones that can cause long-term aqueous phase groundwater contamination. In situ remediation of DNAPL source zones in such systems is crucial for protecting and/or restoring groundwater quality in these aquifer systems having significant groundwater potential. The objective of the project was to investigate the surfactant-enhanced permanganate oxidation efficacy for pool-dominated DNAPL source zones in heterogeneous aquifer media. A complementary objective of this study was to investigate the impact of nonuniform distribution of DNAPL source zones, surfactant-enhanced dissolution and surfactant-enhanced permanganate oxidation conditions on mass-flux reduction/mass-removal behavior relationships. A series of 2-D flow-cell tank experiments using various grain sizes silica sand and natural soil were conducted as part of this study. DNAPL trichloroethene (TCE) was used as a chlorinated solvent, and SDS (sodium dodecyl sulfate) and KMnO₄ (potassium permanganate) were used as anionic surfactant and oxidant (remediation agents), respectively. The results were compared with a water-flooding experiment to test the remediation effort. Although, high fractions of TCE source zones in the heterogeneous porous media were removed by sodium dodecyl sulfate (SDS)-enhanced flushing, TCE removal in this system exhibited an extended multi-step concentration elution behavior. This nonideal behavior was observed for both the water-flood and SDS-flushing experiments. The results emphasized that in the early stage, some portion of the organic liquid is hydraulically accessible (matrix) whereas the later stage of mass removal was controlled by the more poorly accessible mass (pool) associated with higher saturation zones. Our results also showed that the distribution and the emplacement of organic liquid and flow-field heterogeneity had a significant influence on remediation and removal for both flushing solution (SDS and water). It was postulated that when SDS/MnO₄ was applied with sufficient dosage and provided enough contact time, pool-dominated source zones could be remediated more efficiently compared to surfactant flushing alone. As a result, the performance of technology depends on the site characteristics which are critical to characterize effective DNAPL remediation strategies for contaminated sites.

Ibuprofen is commonly detected in onsite wastewater systems. Such onsite systems are abundant in coastal plain areas, globally. Coastal plain soils have unique mineralogy. Rapid subsurface transport may occur in coastal plain soils due to their characteristic permeable soils and seasonally high water tables. Laboratory batch sorption studies were conducted on Norfolk, Goldsboro, and Lynchburg, three archetypical coastal plain soils, with varying physicochemical properties, to evaluate ibuprofen sorption. Sorption distribution coefficients (KD values) across all three soils ranged from 0.63 to 1.26 L kg⁻¹. Sorption of ibuprofen to Norfolk and Goldsboro soils was able to be modeled using a Freundlich isotherm; however, the Lynchburg soil, was not, likely due to soil heterogeneity. In general, sorption of ibuprofen was influenced by soil organic carbon content.

Olive oil production generates a large amount of olive mill wastewater (OMW), the most difficult to treat of agro-industrial effluents. Spreading of OMW across the soilscape has become the most frequently used practice in several Mediterranean basin countries but is hotly debated because of its potential to impair soil environs. The research hypothesis states that soil deterioration is correlated strongly with the spatiotemporal rate of OMW application; thus, the spatial pattern of the soil attributes should be established in conjunction with the rate of OMW spreading. The spatial pattern was ascertained using proximal soil sensing that measures the apparent electrical conductance (ECₐ). Eight representative locations were identified using grouping analysis of the ECₐ data. The soils were analyzed for selected physical and chemical attributes known to be affected by OMW spreading as well as ancillary parameters needed for the calibration of the ECₐ. Discriminant analysis successfully categorized 76% of the ECₐ groups, selecting CEC, sand, pH, and ESP as the most powerful discriminatory variables in the grouping analysis. The correlation coefficients between the measured ECₐ, and the calculated ECₐ, and soil moisture were very high (r > 0.77, P < 0.05), suggesting that the proximal soil survey results are well calibrated. The spreading of untreated OMW over more than 7 years did not impair the soils under study. No significant changes in soil chemo-physical properties such as pH (< 7.66), electrical conductivity in saturated paste (< 3.58 dS m⁻¹), sodium adsorption ratio (< 2.3), potassium adsorption ratio (< 0.33), exchangeable sodium percentage (< 3.85%), and unsaturated hydraulic conductivity (< 0.3 cm h⁻¹) were found in comparison with untreated soils. The results support the premise that moderate quantities of OMW (50–70 m³ ha⁻¹ year⁻¹) equally spread over the soilscape will have little impact on soil health.

Modeling the fate and transport of Escherichia coli is of substantial interest because of how this organism serves as an indicator of fecal contamination in microbial water quality assessment. The efficacy of models used to assess the export of E. coli from agricultural fields is dependent, in part, on submodels they utilize to simulate E. coli release from land-applied manure and animal waste. Although several release submodels have been proposed, they have only been evaluated and compared with data from laboratory or small plot E. coli release experiments. Our objective was to evaluate and compare performances of three manure-borne bacteria release submodels at the field-scale. Models evaluated included the exponential release model (EM), the two-parametric Bradford and Schijven model (B-S), and the two-parametric Vadas-Kleinman-Sharpley model (VKS). Each model was independently incorporated and tested as a submodel within the export model KINEROS2/STWIR, using data of E. coli in runoff. Dairy manure was uniformly applied via surface broadcasting once a year for six consecutive years on a 0.28-ha experimental field site. Two irrigation events followed each application: the first immediately followed the initial application and the second occurred 1 week later. Manure and soil samples were collected before and after irrigation, respectively, and manure, soil, and edge-of-field runoff samples were analyzed for E. coli. Model performance was evaluated with the Akaike criterion, coefficients of determination, and standard error values. The percentage of exported manure-borne E. coli varied from 0.1 to 10% in most cases, generally reflecting the lag time between initiation of irrigation and initiation of edge-of-field runoff. The export model performed better when using the VKS submodel which was preferred in 52% of cases. The B-S and EM submodels were preferred in 24 and 6% of cases, respectively. Submodels were equally efficient in 18% of cases. Two-parametric submodels were ultimately preferred over the single parameter submodel.

Dongmu-1 Medicago sativa seedlings were used as the test material; the variation characteristics soluble protein, soluble sugar, malondialdehyde, proline, chlorophyll, and relative water content were studied under the artificial simulated freeze-thaw (10, 5, 0, − 3, 0, 5, and 10 °C) and combined with deicing salt stress and buffer. The results showed that freeze-thaw and high-salt stress conditions will lead to the damage in the seedling including the membrane system, lipid peroxidation, and severe dehydration. Because of the self-regulating system as well as a certain degree of resistance, the plants can accumulate plenty of substances such as soluble protein, soluble sugar, and proline so as to regulate the osmotic potential. The content of soluble protein, malondialdehyde, soluble sugar, and proline in different treatment groups rose first and then decreased within a freeze-thaw cycle, among which the content of soluble protein reached the maximum value at 0 °C (t3), 20.82, 18.96, and 17.97 mg/g, respectively. The figure for malondialdehyde and proline peaked at − 3 °C (t4) while soluble sugar content peaked at 0 °C (t5). However, during this period, there were no apparent regulations for chlorophyll content and relative water content in each treatment group. Beyond that, due to the different intensity of compound stress, the seedlings showed different adaptability, and the degree of changes in physiological indexes appeared to be combined freeze-thaw and deicing salt stress > single freeze-thaw stress > combined freeze-thaw, deicing salt stress, and buffer, illustrating that buffer can alleviate the degree of the damage from freeze-thaw and deicing salt stress on M. sativa seedlings to some extent.

In this study, the ability of two different water treatment residuals (Fe- and Al-WTRs) to accumulate antimony(V) from an aqueous solution was investigated at different pH values (pH 4.5 and 6.5). Both WTRs showed a maximum Sb(V) sorption capacity of approx. 0.22 mmol g⁻¹ at pH 4.5 which declined at pH 6.5, particularly for Fe-WTR (i.e., 0.059 and 0.163 mmol g⁻¹ of Sb(V) sorbed by Fe- and Al-WTRs respectively). The greater capacity of WTRs to accumulate antimonate at pH 4.5 seemed to be linked to their chemical properties, such as the pHPZC and the specific surface area. At both pH values, the Sb(V) sorption by Al- and Fe-WTRs followed a pseudo-second-order kinetic model, while the sorption isotherms data fitted the Freundlich model better than the Langmuir one, suggesting the presence of heterogeneous Sb(V) adsorption sites. The sequential extraction of WTR-Sb(V) systems showed that a significant amount of Sb(V) was retained by WTRs through chemical interactions, i.e., through the formation of inner sphere surface complexes [e.g., Fe/Al–O–Sb(V)]). This was particularly relevant at higher pH values (pH 6.5) where more than 60 and 50% of the Sb(V) sorbed by Fe- and Al-WTRs respectively was retained by specific chemical bonding. The residual Sb(V) was higher for the Al-WTR at both pH values, and the highest amount of residual Sb(V) was recorded at pH 4.5 [> 65% of the total Sb(V) sorbed]. SEM-EDX analysis of the WTR-Sb(V) systems showed that antimony was mainly associated with Fe and Al, thus supporting the Sb(V) affinity for Al/Fe oxy-hydroxides. Treatment of WTR-Sb(V) systems with citric and malic acids, at concentrations relevant in the rhizosphere, indicated that Sb(V) could be released by both acids, with 4.5 mM citric acid favoring the highest Sb(V) release in both WTRs. The results from this study suggest that WTRs could be used as alternative amendments for the in situ immobilization of Sb(V) in acidic or circumneutral polluted soils.