Pre-oxidation in water treatment is considered an effective method to enhance the removal of algal cells and their exuded organic matters. However, pre-oxidation also alters the characteristics of algae and consequently influences disinfection processes. The existing studies mainly focused on the stationary growth phase, but little is known for the exponential and declined phases. The objectives of this study were to examine the effects of pre-ozonation on the integrity of algal cells, the release of algal organic matters, and the formation of disinfection by-products like N-nitrosodimethylamine (NDMA) from Microcystis aeruginosa (M. aeruginosa) at three growth phases. The results demonstrated that pre-ozonation was efficient to inactivate M. aeruginosa cells. The severity of M. aeruginosa cell damage increased as the ozone dosage increased from 0.5 to 2.0 mg/L. The damage of cell membranes resulted in the release of intracellular organic matters. Excitation-emission matrix spectra (EEMS) analysis indicated that ozone mainly reacted with soluble microbial products (SMP). With the increase of ozone concentration, although the trend of NDMA formation was similar for all three growth phases, more production of NDMA by algal cells was observed at the declined phase. In the post-disinfection process, chloramine showed the potential as a more suitable disinfectant than chlorination after pre-ozonation to minimize the NDMA formation. Therefore, appropriate pre-ozonation is beneficial to reduce the NDMA formation from exponential algae, while has no significant change during both stationary and declined phases.

The current study highlighted the phytoremediation potential of Bacopa monnieri (L.) Pennell for most commonly used azo dyes which are resistant to degradation. Fourteen azo dyes (reactive: 09; direct: 05) upon treatments up to 40 mg/L were decolorized in the range of 90 to 100% after incubation of 2 weeks in in vitro and hydroponic cultures. No significant alteration in growth of B. monnieri was observed in the presence of dyes R. Magenta MB, R. Navy Blue M2R, Dt. Orange RS, Dt. T Blue GLL, Dt. Sky Blue FF alone, and together in the medium. However, at increasing concentrations (60–100 mg/L), the percent dye decolorization was declined and showed a toxic effect on plant growth. The chlorophyll content declined while membrane damage and osmolyte accumulation were increased in dye treated samples. The biological conversion of produced metabolites was analyzed using FTIR and GC-MS. Our results suggest that the intermediates of Dt. Blue GLL degradation consist L-Proline, N-valeryldecyl ester, 3,5 Di-tert-butyl-4-trimethylsiloxytoulene, and 1,2-benzenedicarboxylic acid, diisooctyl ester. The antioxidative and oxidative enzyme activities in roots and leaves were significantly higher in the presence of dyes over control indicate that these enzymes are involved in degradation of dyes. Percentage seed germination, shoot and root length of seedlings of legume, cereal, and oilseed crop was not affected, suggesting the compatible nature of the produced metabolites. Our results revealed the remarkable ability of Bacopa monnieri for long-term operations that lead to the practical application of phytoremediation in textile industries.

Silica-based nanocomposite syntheses employ many harmful substances, which, in turn, demand the development of new synthetic environmental-friendly routes that meet the principles of green chemistry. In this work, we present a novel magnetic adsorbent, Fe₂O₃@SiO₂ nanocomposite (Fe@SiNp), successfully obtained without surfactant, employing an electrochemical method. We characterized the nanocomposite and then applied it to remove aniline from the water medium. Characterization was carried out by vibrating-sample magnetometry (VSM), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FT-IR). The parameters to the adsorptive removal of aniline were successfully optimized, which made possible to remove 71.04 ± 0.06% (126.6 ± 2.0 mg/g) from a 100 mg/L aniline solution at pH 6 and 323 K, by employing around 50 mg of Fe@SiNp, at a contact time of 40 min. The adsorption of aniline by Fe@SiNp is a spontaneous and exothermic process according to the pseudo-second-order kinetic model (r² = 1 at 20 mg/L aniline concentration) and the Freundlich isotherm model (r² = 0.9986).

A complete orthogonal experiment using a pot test is conducted to investigate the effects of four amendments (biochar, peat, manure, and non-contaminated soil (NCS)) on the metal availability, mobility, and phytostabilization potential of an energy crop, king grass (Pennisetum purpureum × P. thyphoideum), in Pb/Zn mine tailings. The addition of amendments significantly increased the pH and fertility of the tailings, while significantly decreasing the heavy metal available contents in the tailings. The available Cd, Pb, Zn, and As concentrations in the tailings in the treatment amended with biochar+NCS+peat+manure were 51.00%, 36.62%, 50.57%, and 75.88%, respectively, lower than those in the treatment control. The king grass survived in the tailings without amendments, while amendments made the plant grow well or better in the tailings than in NCS. The addition of amendments significantly reduced the content of heavy metals and bioaccumulation factor (BCF) in the plant root but increased the translocation factor (TF) of Cd, Zn, and As and had little effect on the TF of Pb. The TF for heavy metals in plant were lower than one for all of the treatments. During a leaching period of 30 days, the pH of the leachate declined slowly and then maintained at 6.0~6.6. The addition of the amendments significantly reduced the metal concentrations of the leachates, and the highest declines were 50.46%, 20.04%, 41.58%, and 47.04% for Cd, Pb, Zn, and As, respectively. Biochar had a higher immobilization capacity for Cd, Pb, Zn, and As than manure, peat, and NCS. King grass could be used to aid phytostabilization for Cd- and Pb-polluted tailings, and biochar-rich amendments were effective for the in situ immobilization of metals. Further field monitoring is necessary to demonstrate the effectiveness of king grass and amendments under the climatic conditions of China.

Eutrophication models are of great importance and are valuable tools for the development of policy and legislation. However, the parameter uncertainty and substantial computational cost lead to difficulties in decision-making, especially for complex models with multiple indicators. A multicriteria uncertainty analysis and parameter estimation (MUAPE) method, which selected behavioral parameters combined with Pareto domination and simultaneously obtained acceptable values for modeling by the maximum likelihood concept and kernel density estimation, was shown. This method, which did not assign thresholds and weights, was applied to analyze the uncertainty of the Chaohu Lake eutrophication model and estimate parameters. The results of the behavioral parameters were compared using different criterion sets, the relative error (RE) and the root mean square error (RMSE), and the results showed little discrepancy in terms of the effects on parameter uncertainty represented by the marginal probability density. The uncertainties of the parameters related to algal kinetics (i.e., BMR, PM, and KESS) were smaller than those of nutrient- and temperature-related parameters (i.e., KDN, Nitm, KTB, and KTHDR) for both sets of criteria. However, the reduction in the joint uncertainty of the two parameters was greater when RE was used than when RMSE was used. The acceptable values for the key parameters of the Chaohu Lake eutrophication model were also obtained by the RE criterion. The results strongly agreed with the observed values, and parameters could be applied for model prediction. This result indicated that the combination method was not only practical for reducing parameter uncertainty but also useful for determining parameter values. This method provides a basis for multicriteria uncertainty analysis and parameter estimation in eutrophication modeling.

The levels of trace elements (As, Hg, Cr, Cd, Pb, Co, Ni, Cu, Mn and Zn) in commercially important fish species sampled from fish markets of Adelaide, Australia; canned fish from South Australian supermarkets; and fish markets of West Bengal, India were determined by inductively coupled plasma mass spectrometry (ICP-MS) after microwave digestion. Mercury was determined by using triple quadrupole ICP-MS. The accuracy of the methods was assessed with a certified standard reference material (NRCC-DORM-3 dogfish protein), and the results were compared with values reported in the literature. The results indicated considerable variations in the accumulation of trace elements among the fish species. The relationship between species with respect to trace element concentrations was examined using cluster analysis, which showed Indian fish species forming distinct groups from the others. Other than As in sardines, whiting and snapper and Hg in swordfish and snapper, the trace element concentrations were within permissible limits recommended by various standards. Based on the estimated daily intake (EDI), fish samples analysed in this study can be considered safe for human consumption as per the recommended daily dietary allowance limit fixed by various agencies. Continuous monitoring and assessments of fish metal(loid) content are needed to generate more data and safeguard human health.

Carbon emissions in the transportation sector are of great concern, since they are the third leading contributor to China’s carbon emissions. This research examines the decoupling relationship between economic outputs and carbon emissions of 11 provinces in 2000–2016 by focusing on Yangtze River Economic Belt (YREB), which is the densest traffic and economic corridor in China. Although many studies have focused on the decoupling state and its driving forces between economic outputs and carbon emissions, few studies further addressed the microscale analysis for decoupling drivers. This paper reveals the characteristic, inequality contribution ratio, and dynamic evolution of the drivers by integrating Dagum’s Gini ratio with kernel density estimation in YREB. Results are as follows: (1) The decoupling states presented weak decoupling state at the whole belt in the majority of the latter observed sub-periods. The decoupling states at the provincial level turned more satisfactory during the four observed sub-periods, especially for Shanghai and Zhejiang. (2) The energy intensity (EI) effect is the predominant driver for promoting the decoupling state in the vast majority of provinces, whereas value added per capita effect is the major role for inhibiting the decoupling state. (3) During the four observed sub-periods, the Gini inequality and transvariation intensity of the EI effect between sub-regions are the main sources of the provincial differences in YREB. The driving force of EI effect is increasing, but the provincial differences are expanding in the upstream and downstream regions by analyzing its dynamic evolution. Understanding the temporal and spatial microscale inequality of the decoupling drivers provides governments with differentiated and forward-looking suggestions towards coordinating regional economic growth and carbon emissions reduction.

Zinc is one of the important essential trace minerals to human health due to its antioxidant properties. The present study was conducted to elucidate its potential protective role against maneb-induced nephrotoxicity. For this purpose, animals were randomly divided into four groups of six each. Mice of group I (negative controls) have received daily 0.5 ml of distilled water, a solvent of maneb. Mice of group II (MB) have received 30 mg/kg bw of maneb daily by intraperitoneal way. Mice of group III (MB + Zn) have received the same dose of maneb as group II, along with ZnSO₄ (30 mg/kg bw) daily. Mice of group IV (Zn), considered as positive controls, have received the same dose of ZnSO₄ as group III daily. Our results revealed that ZnSO₄ co-administration to maneb-treated mice decreased kidney levels of malondialdehyde, hydrogen peroxide, protein carbonyls, and advanced oxidation protein products; the levels of non-enzymatic antioxidants like vitamin C, glutathione, and metallothionein. It recovered the alteration of antioxidant enzyme activities (catalase, superoxide dismutase, and glutathione peroxidase) and attenuated DNA fragmentation. Furthermore, this essential trace element was also able to alleviate kidney biomarkers’ alterations by lowering plasma levels of creatinine, urea, uric acid, and lactate dehydrogenase. In addition, the histopathological changes induced by maneb were improved following zinc administration. Our results indicated that zinc might be beneficial against maneb-induced renal oxidative damage in mice.

Agricultural wastes have promising potential for the production of low-cost and sustainable adsorbents for heavy metals, while the characteristics of those biosorbents and the stability of the passivated heavy metals under natural conditions need to be studied further. In this paper, the oilseed rape plant after seed harvesting was divided into three parts: root (RT), stem (ST), and pod (PD). The isotherm adsorption of cadmium (Cd(II)) on the biomass was conducted. In practice, the biomass was aged in the Cd(II)-contaminated soil, and the concentration of Cd(II) in the leachate was measured after the continuous eluent of typical acid rain. The components and elements of the biomass were determined for the analysis of the differences between the immobilization abilities of the biomass. Results showed the CC (corn cob, as a comparison), ST, RT, and PD had the adsorption capacities of 6.34, 7.58, 9.22, and 9.87 mg/g for Cd(II) through the Langmuir fitting of the isothermal adsorption experiments, respectively. The leached Cd(II) were reduced 1063, 2073, 2824, and 3621 μg by CC, ST, RT, and PD biomass aging, respectively. Compared that by CC, the immobilization differences between the biomass in soil were much greater than that in isotherm adsorption, indicating the biosorption ability of rape biomass was enlarged during the 30 days of aging. Nitrogen, phosphorus, and sulfur contents showed sequences as pod>root>stem and had high correlations with the reduced amount of leached Cd(II), which indicated protein might be beneficial for the enhancement of adsorption/immobilization in the soil.

Fipronil (FIP) is a highly effective, broad-use insecticide that belongs to the phenylpyrazole chemical group. It is extensively used in the agriculture and veterinary medicine for controlling a wide variety of pests. Though FIP showed lower toxicity in vertebrates than in insects, it was recognized to have a variety of toxic effects in mammals. The present study was undertaken to evaluate FIP-induced alterations in the blood biochemical markers and oxidative stress parameters in male albino mice via oral sub-acute toxicity exposure. The possible ameliorative effect of the pretreatment with selenium plus α-tocopherol (vitamin E) against the harmful effects of FIP was also investigated. Mice in FIP-test groups were exposed to different sublethal doses, i.e., 1.43, 2.87, and 4.78 mg active ingredient (AI)/kg body weight (b.w.), equal to 1/100, 1/50, and 1/30 LD₅₀ of FIP, respectively, for 28 days. Mice in the amelioration groups were orally administered with selenium + vitamin E (0.3 mg + 22.5 mg/kg b.w., respectively) 14 days prior to exposure to the higher dose (4.78 mg/kg) of FIP for another 14 days. Fipronil exposure at medium and high doses showed lowered values of red blood cell count (RBC), hematocrit (HCT), hemoglobin (HGB), white blood cell (WBC), and platelet (PLT) counts after 28-day exposure, compared to the control. All three doses caused significant increases in levels of liver-function biomarkers, i.e., aspartate amino transaminase (AST), alanine amino transaminase (ALT), alkaline phosphatase (ALP), cholesterol, and bilirubin levels compared to the control. Levels of biomarkers related to kidney functions, i.e., urea, uric acid, and creatinine, increased significantly than these of the control. Likewise, the oxidative stress indices, i.e., hydrogen peroxide (H₂O₂) and malondialdehyde (MDA), significantly increased at the higher and medium doses, while antioxidant enzymes, catalase (CAT) and superoxide dismutase (SOD), decreased significantly. On the other hand, prior administration of selenium + vitamin E in the FIP-exposed mice led to restore values of most hematological parameters nearly to these of the control. Also, the levels of AST, total protein, and creatinine seemed to be restored to the control values. Interestingly, pretreatment with selenium + vitamin E restored the levels of antioxidant enzymes, CAT and SOD, to the control values, whereas, oxidative stress indices, H₂O₂ and MDA, remained significantly high. It is our thought that the sublethal dose less than 1.43 mg/kg b.w. of commercial formulation of FIP (COACH® 200 SC) could be considered as no-observed-adverse-effect-level(NOAEL) under our present experimental conditions at short-term toxicity study. On the other hand, the higher sublethal doses, 4.78 and 2.87 mg/kg b.w., induced significant adverse effects in biomarkers and may be deleterious to human health following long-term exposure.