Phosphorus is one of the main nutrients required for all life. Phosphorus as phosphate form plays an important role in different cellular processes. Entrance of phosphorus in the environment leads to serious ecological problems including water quality problems and soil pollution. Furthermore, it may cause eutrophication as well as harmful algae blooms (HABs) in aquatic environments. Several physical, chemical, and biological methods have been presented for phosphorus removal and recovery. In this review, there is an overview of phosphorus role in nature provided, available removal processes are discussed, and each of them is explained in detail. Chemical precipitation, ion exchange, membrane separation, and adsorption can be listed as the most used methods. Identifying advantages of these technologies will allow the performance of phosphorus removal systems to be updated, optimized, evaluate the treatment cost and benefits, and support select directions for further action. Two main applications of biochar and nanoscale materials are recommended.

A green house experiment was conducted to evaluate the efficacy of soil application of selenium (Se) in modulating metabolic changes in rice under arsenic (As) stress. Rice plants were grown over soil amended with sodium arsenate (25, 50 and 100 μM kg⁻¹ soil) with or without sodium selenate @ 0.5 and 1 mg kg⁻¹ soil in a complete randomized experimental design, and photosynthetic efficiency, nutrient uptake and nitrogen metabolism in rice leaves were estimated at tillering and grain filling stages. Se treatments significantly improved the toxic effects of As on plant height, leaf dry weight and grain yield. Arsenate treatment reduced uptake of Na, Mg, P, K, Ca, Mn, Fe and Zn and lowered chlorophyll, carotenoids and activities of enzymes of nitrogen metabolism (nitrate reductase, nitrite reductase, glutamine synthase and glutamate synthase) in rice leaves at both the stages in a dose-dependent fashion. Se application along with As improved photosynthesis, nutrient uptake and arsenate-induced effects on activities of enzymes of nitrogen metabolism with maximum impact shown by As50 + Se1 combination. Application of Se can modulate photosynthetic efficiency, nutrient uptake and alterations in nitrogen metabolism in rice Cv PR126 due to As stress that helped plants to adapt to excess As and resulted in improved plant growth.

Cadmium (Cd) being a non-essential, mobile, and toxic heavy metal, negatively affects the plant growth and physiology. Current work investigated the impact of Serratia marcescens CP-13 inoculation on root organic acids and nutrient exudates of two maize cultivars varying in Cd tolerance under induced Cd toxicity. Seedlings of Cd-sensitive (Sahiwal-2002) and Cd-tolerant (MMRI-Yellow) cultivars were grown either inoculated or non-inoculated with CP-13 in Petri plates having various Cd stress levels (0, 6, 12, 18, 24, 30 μM). Seedlings were transferred to rhizoboxes for the collection of root exudates and analysis of physio-biochemical traits. Both maize cultivars exuded higher organic acids and nutrient exudates under non-inoculated conditions as compared to inoculated ones. Non-inoculated tolerant cultivar exhibited higher nutrient accumulation, biomass, antioxidants, total chlorophyll, Cd release meanwhile reduced Cd uptake, lipid peroxidation, exudation of organic acids, and nutrients than the sensitive one. However, under CP-13 inoculation, Cd sensitive cultivar exhibited less exudation of organic acids (citric acid, acetic acid, malic acid, glutamic acid, formic acid, succinic acid, and oxalic acid), nutrients mobilization (K, Na, Zn, Ca, and Mg), total chlorophyll, antioxidants (APX, SOD, POD), total soluble sugar, diminished MDA, and Cd uptake. The significant reduction in release of root exudates by both cultivars was likely due to the plant growth promoting traits of CP-13 which confer Cd tolerance. The maximum release of rhizospheric root exudates were documented at 30 μM applied Cd stress. Therefore, the Serratia sp. CP-13 was proposed as a potential inoculant for bioremediation of Cd together with maize cultivars.

This study used biogas residue produced by anaerobic fermentation of food waste as the raw material in large-scale windrow composting. The effects of the addition of a microbial consortium on the physical and chemical properties and stability of composting of biogas residue were studied. The maturity of food waste biogas residue during composting was investigated by multivariate interaction of environmental, maturity, and nutrient parameters, using structural equation modeling (SEM). Results showed that the temperature of T2 compost with the microbial consortium increased more rapidly. The pH ranges of T1 (without the microbial consortium) and T2 were 8.75–9.15 and 8.42–9.27, respectively; the electrical conductivity (EC) ranges of T1 and T2 were 2.74–3.95 mS/cm and 2.81–3.85 mS/cm, respectively; the degradation rates of organic matter (OM) in T1 and T2 were 21.74% and 33.62%, respectively; and the total nitrogen (TN) ranges of T1 and T2 were 1.93–3.10% and 1.80–3.21%, respectively. By the end of composting, the germination indices (GI) of T1 and T2 were 20.57% and 64.24%, respectively. The total oxygen consumption after 4 days (AT₄) was 1.88 mg-O₂/g and 1.2 mg-O₂/g in T1 and T2, respectively. SEM of T1 showed that compost temperature and EC were important factors affecting compost maturity. These factors highly significantly affected OM, which in turn affected AT₄ of the biogas residue composting. SEM of T2 showed that compost temperature, pH, and EC affected OM, which in turn affected compost maturity. Temperature affected compost maturity by affecting AT₄ and GI. Principal component analysis (PCA) showed that the overall score of T2 was higher than that of T1, indicating that the addition of the microbial consortium was beneficial for industrial-scale composting of biogas residue produced by anaerobic digestion of food waste.

Groundwater is an important resource of water in arid and semi-arid agricultural regions. Thus, identification of hydrogeochemical characters and the influence of geospatial variability and flow pooling are of significance on groundwater resources management and making irrigation decisions in salinized areas. The study specifically focused on the Hetao Irrigation District located in the semi-arid region of northern China. A total of 85 groundwater samples (42 from the upstream Shenwu Irrigation Area (SWIA), 43 from the downstream Wulate Irrigation Area (WLTIA)) were collected, and 15 water quality indexes were analyzed. Methods including mathematical statistics, Piper diagram, Gibbs model, forward succession model, and ionic rations were used to analyze the hydrochemical characteristics and evolution mechanisms, RSBC, PS, SAR, WQI were selected to evaluate water quality and irrigation suitability from the perspective of salt and alkali damage. Results showed that the groundwater of the study area is weakly alkaline, SWIA is mainly fresh water (47.62%), WLTIA is mainly brackish water (65.12%), and the hydrochemistry of the groundwater consists of Cl–Na type and Cl·SO–Ca·Mg. The solute content of downstream (WLTIA) is higher than that of upstream (SWIA), Na⁺ and Cl⁻ have obvious advantages in WLTIA, and they are the main contribution indicators of groundwater TDS in the study area. The groundwater is subjected to the ongoing influence of rock weathering, ions exchange, and evaporate crystallization Na⁺ mainly originates from the dissolution of evaporate salt rock and silicate rock, and Ca²⁺ from the dissolution of gypsum and carbonate. The order of contribution of different rocks is evaporation rock > silicate rock > carbonate rock. Based on the classifications of sodium absorption ratio (SAR), residual sodium bicarbonate (RSBC), and potential salinity (PS), most of the groundwater samples are unsuitable for irrigating, and the groundwater quality of the SWIA is better than that of the WLTIA.

An increasing number of studies examined the potential effects of PM₁ (submicronic particulate matter with an aerodynamic diameter ≤ 1 μm) on the risk of respiratory diseases; however, the results have been inconclusive. This study aimed to determine the overall association between PM₁ with total and cause-specific respiratory diseases. A systematic review and meta-analysis was conducted with 68 related articles retrieved, and six articles met the full inclusion criteria for the final analysis. For a 10 μg/m³ increase in PM₁, the pooled odds ratio (OR) was 1.05 (95% CI 0.98–1.12) for total respiratory diseases, 1.25 (95% CI 1.00–1.56) for asthma, and 1.07 (95% CI 1.04–1.10) for pneumonia with the I² value of 87%, 70%, and 0%, respectively. Subgroup analyses showed that long-term exposure to PM₁ was associated with increased risk of asthma (OR 1.47, 95% CI 1.33–1.63) with an I² value of 0%, while short-term exposure to PM₁ was not associated with asthma (OR 1.07, 95% CI 0.89–1.27) with the I² value of 0%. Egger’s test showed that publication bias existed (P = 0.041); however, the funnel plot was symmetrical with the inclusion of the moderator. In conclusion, elevated levels of PM₁ may increase morbidity in total and cause-specific respiratory diseases in the population.

In the present work, plasma remediation of p-nitrophenol (PNP) contaminated soil was performed in a novel spray-type coaxial cylindrical dielectric barrier discharge (DBD) system at ambient temperature. This system is capable of generating large-size nonthermal plasma (NTP) and improving the diffusion and transfer of chemical active species around the dispersed soil particles. Several key parameters including plasma treatment time, discharge voltage, soil granular size, the entry speed of soil, PNP initial concentration, gas variety, and gas flow rate were investigated in terms of PNP degradation and energy efficiencies. Under the optimized experimental conditions, 54.2% of PNP was degraded after only 50 s discharge treatment, indicating that the spray-type coaxial cylindrical DBD system can degrade organic pollutants in soil more quickly compared to other plasma systems due to its efficient transfer of reactive oxygen and nitrogen species (RONS) into the contaminated soil. The possible PNP degradation pathways were proposed based on intermediates identification results and the role of reactive species analysis. The toxicological assessment of the PNP decomposition products was conducted by quantitative structure-activity relationship (QASR) analysis. This work is expected to provide a potential plasma technology for rapid and efficient processing of industrial organic pollutants contamination soil.

This is the first study to monitor anesthetic pollution in veterinary operating rooms (VOR) and assess the toxicological impact of the inhalational anesthetic isoflurane (exposed group) compared to matched volunteers (control group). DNA damage was evaluated in mononuclear cells by the comet assay while genetic instability (including micronucleus-MN), cell proliferation, and cell death markers were assessed by the buccal MN cytome assay. Residual isoflurane concentrations in VOR (air monitoring) lacking the scavenging system were assessed by infrared spectrophotometry; the mean concentration was 11 ppm (≥ 5 times above the international recommended threshold). Comet assay results did not differ between groups; however, both younger exposed professionals (with higher week workload) compared to older individuals exposed for the same period and older professionals with greater time of exposure (years) compared to those in the same age group with fewer years of exposure presented higher DNA damage. The exposed group had a higher frequency of MN, nuclear buds, binucleated cells, karyorrhexis, and karyolysis and a lower frequency of basal cells than the control group. Exposed women were more vulnerable to genetic instability and proliferative index; exposed men presented more cytotoxicity. High WAG exposure has deleterious effects on exposed professionals.

Photocatalytic technology has been widely studied by researchers in the field of environmental purification. This technology can not only completely convert organic pollutants into small molecules of CO₂ and H₂O through redox reactions but also remove metal ions and other inorganic substances from water. This article reviews the research progress of graphene-based photocatalytic nanocomposites in the treatment of wastewater. First, we elucidate the basic principles of photocatalysis, the types of graphene-based nanocomposites, and the role of graphene in photocatalysis (e.g., graphene can accelerate the separation of photon-hole pairs and increase the intensity and range of light absorption). Second, the preparation, characterization, and application of composites in wastewater are introduced. We also discuss the kinetic model of the photocatalytic degradation of pollutants. Finally, the enhancement mechanism of graphene in terms of photocatalysis is not completely clear, and graphene-based photocatalysts with high catalytic efficiency, low cost, and large-scale production have not yet appeared, so there is an urgent need for more extensive and in-depth research.