Microcystis aeruginosa is a common cause of algal bloom outbreaks in Chinese lakes. This study investigated the effects of phosphate loading on the algal growth and extracellular organic matter (EOM) production of M. aeruginosa. The cell density was monitored by cell counting, and EOMs were characterized by dissolved organic carbon (DOC), carbohydrate, protein, and excitation/emission matrix fluorescence spectroscopy (EEM). DOC concentration peaked during the stationary phase and was contributed primarily by amino acid- and fulvic-like substances. Carbohydrate was a substantially larger fraction than protein. Phosphate showed positive influence on the cell growth and EOMs. As its concentration increased, the EOMs concentration increased. So did EOM and β-ionone as typical taste and odor compounds. Whatever the phosphate concentration was, the peak of β-ionone concentration exceeded its odor threshold (7.0 ng/L), resulting in a severe fruit-like odor. Additionally, the disinfection by-products involved with EOM were evaluated in both chlorination and chloramination, indicating that trihalomethanes were the dominated toxic by-products and the chloramination showed more significant effect on its formation as an interesting result.

Pilot scale thin film plate reactors (TFPR) were fabricated to study the solar photocatalytic treatment of wastewater obtained from the secondary treatment plant of a sugar refinery. Silver-impregnated titanium dioxide (TiO₂) was prepared by a facile chemical reduction method, characterized, and immobilized onto the surface of ceramic tiles used in the pilot scale reactors. On 8 h of solar irradiation, percentage reduction of chemical oxygen demand (COD) of the wastewater by Ag/TiO₂, pure TiO₂, and control (without catalyst) TFPR was about 95, 86, and 22 % respectively. The effects of operational parameters such as, flow rate, pH, and addition of hydrogen peroxide (H₂O₂) were optimized as they influence the rate of COD reduction. Under 3 h of solar irradiation, 99 % COD reduction was observed at an optimum flow rate of 15 L h⁻¹, initial pH of 2, and addition of 5 mM of H₂O₂. The results show that Ag/TiO₂ TFPR could be effectively used for the tertiary treatment of sugar refinery effluent using sunlight as the energy source. The treated water could be reused for industrial purposes, thus reducing the water footprint of the industry. Graphical Abstract Sugar refinery effluent treatment by solar photocatalytic TFPR

The chemical reduction of hexavalent chromium (Cr(VI)) by combined zerovalent magnesium (ZVMg) and ultrasound (US) was studied under batch conditions. Results have demonstrated that the reduction of Cr(VI) mediated by ZVMg enhanced significantly with the ultrasonic effect. The percent reduction of Cr(VI) by ZVMg (5 g/L) was about 20 % after 60 min, but its complete reduction was attained within an hour when ultrasound was applied at a power of 100 W. The efficiency of Cr(VI) reduction increased with increasing ultrasonic power and magnesium dose. The synergy of the combined treatment has been attributed to the surface activation of ultrasonic treatment. Scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), atomic absorption spectrophotometer (AAS), pH, and X-ray diffraction (XRD) analyses have revealed that magnesium and chromium hydroxides and hydroxide ion were three major by-products during the reduction of Cr(VI) by US/ZVMg under pH-uncontrolled conditions. The proposed method does not require acid and buffer addition and has an advantage of removing Cr(VI) and its by-product (Cr(III)) simultaneously.

Ninety-seven seasonal, passive indoor and outdoor air samples were collected in Shanghai to study polybrominated diphenyl ethers (ΣPBDEs, 16 congeners including BDE-209), their concentrations, composition profiles, seasonal variations, influencing factors, emission sources, and human inhalation exposure. In summer, median indoor concentrations of Σ ₁₅ PBDEs (excluding BDE-209) were 82 pg m⁻³ in offices and 30 pg m⁻³ in homes, ∼3 times the winter concentrations. The average summer concentration of 130 pg m⁻³ BDE-209 in homes was higher than that in offices (which was 90 pg m⁻³); in winter, home and office concentrations were similar (46 and 47 pg m⁻³, respectively). For outdoor air, the median concentration of Σ ₁₅ PBDEs in summer (12 pg m⁻³) was twice the winter concentration (6 pg m⁻³), while the summer median concentration of BDE-209 (398 pg m⁻³) was half the winter concentration (794 pg m⁻³). Higher concentrations of Σ ₁₅ PBDEs indoors compared with outdoors showed that the lower brominated BDEs found were mainly from indoor sources. Meanwhile, the much lower indoor concentration of BDE-209 compared with the outdoors showed that BDE-209 came mainly from outdoor sources. The data set also indicated that electric/electronic appliances were the main sources of indoor ΣPBDEs, and old appliances emitted more lower brominated BDEs, while industrial emissions should be the main source of the outdoor BDE-209. Median daily human exposures to Σ ₁₅ PBDEs and BDE-209 through inhalation were estimated to be 0.23 and 1.73 ng day⁻¹ in winter and 0.65 and 2.28 ng day⁻¹ in summer for adults. The human inhalation exposure to ΣPBDEs (3.44 ng day⁻¹ for adults and 1.33 ng day⁻¹ for toddlers) was comparable to that from eating contaminated fish for both toddlers and adults in Shanghai.

In this study, the effect of flue gas CO₂ on growth, lipid production, and fatty acid composition of a green microalga Acutodesmus obliquus KGE 30 was investigated. The highest growth rate (0.46 g L⁻¹ and μₘₐₓ = 1.09 day⁻¹), total inorganic carbon removal (95.9 mg L⁻¹), and lipid productivity (20.1 mg L⁻¹ day L⁻¹) was obtained at 14.1 % CO₂ after 4 days of cultivation. In a semicontinuous batch reactor, the highest biomass production (1.19 g L⁻¹) was achieved after 12 days with continuous injection of flue gas CO₂. Compared with synthetic CO₂, fatty acid methyl ester analysis showed that the amount of unsaturated fatty acid increased by 19.2 % with 14.1 % flue gas CO₂. The application of flue gas CO₂ improved biomass production and lipid productivity in A. obliquus. The current investigation demonstrated that the use of flue gas CO₂ could reduce the cost of microalgae biomass production for better biofuel generation.

Waste water treatment plants (WWTP) have attracted attention in numerous studies in their impact on receiving surface waters because of the presence of varied contaminants in their effluents. This study investigated the relevance of particle-bound contaminants using suspended particulate matter (SPM) to monitor the temporal variability of the impact of a WWTP discharge in a chalk stream (Loue River) in France. We performed five sampling campaigns of SPM and sediment during a year at different seasons and analyzed polycyclic aromatic hydrocarbons (PAHs) and phosphorus in both matrix. PAH contents in SPM ranged from 675 to 3709 μg kg⁻¹ dry weight (dw) and in sediment from 668 to 7712 μg kg⁻¹ dw. Levels of phosphorus ranged from 364 to 1380 mg kg⁻¹ dw in SPM and from 315 to 523 mg kg⁻¹ dw in sediment. The WWTP increased significantly PAH levels in SPM to the Loue River. However, our results did not allow to evidence significant differences on particulate phosphorus concentration in SPM. Nevertheless, we evidenced significant seasonal variations of PAH and phosphorus concentrations in SPM. Besides sediment sampling, the collection of SPM allowed to monitor changes in contamination from the WWTP and highlighted impact of WWTP on PAH concentrations and changes of PAH and phosphorus concentrations over time. Contamination of SPM of the Loue River was driven by mixed inputs from point source like WWTP and from diffuse sources in the catchment like runoff from impervious and pervious surfaces. Combining monitoring of SPM and sediment proved to be an improved approach to assess contamination of local and diffuse sources in chalk streams.

The aim of this study was to evaluate the spatial distribution of total petroleum hydrocarbons (TPH) in rhizoplane and non-rhizosphere of Leersia hexandra, known as Japanese grass, the effect of oil on the aerial biomass of L. hexandra, the population of plant growth-regulating bacteria, and microbial respiration in rhizosphere and non-rhizospheric soil. Samples of rhizosphere and soil were collected at 14 points across a surface of 2.3 ha, layer 1 (0–15-cm depth), layer 2 (15–30 cm), and layer 3 (30–70 cm), to measure TPH (mg kg⁻¹). The spatial distribution of TPH defined four study zones (Z): Z1: 1393, Z2: 3455, Z3: 5574, and Z4: 7544. TPH were higher in underlying layers in the four zones. Zone 2 produced the largest amount of aerial biomass; oil induced hormesis in the grass, but inhibited it at doses ≥5574. For the rhizosphere of L. hexandra, it was cut with a sterilized knife, stimulated the population of N-fixing and phosphorus solubilizing, heterotrophic bacteria, as well as microbial respiration (day 1, 14, 21, 42, and 63 after incubation) in the four zones. The population of the three groups of bacteria was more stimulated by weathered oil in rhizosphere soil, compared to non-rhizosphere soil and with control treatment, suggesting that the rhizosphere system of L. hexandra has the potential to bioestimulate beneficial microbial activity in unpolluted and polluted areas compared to non-rhizosphere soil. We recommend the use of L. hexandra to recover soils degraded by weathered oil in farms located in the Mexican humid tropics.

Microarray platforms are a good approach for assessing biological responses to pollution as they enable the simultaneous analyses of changes in the expression of thousands of genes. As an omic and non-targeted methodology, this technique is open to unforeseen responses under particular environmental conditions. In this study, we successfully apply a commercial oligonucleotide microarray containing Mus musculus whole-genome probes to compare and assess the biological effects of living in a heavily polluted settlement, the Domingo Rubio stream (DRS), at the Huelva Estuary (SW Spain), on inhabitant free-living Mus spretus mice. Our microarray results show that mice living in DRS suffer dramatic changes in gene and protein expression compared with reference specimens. DRS mice showed alteration in the oxidative status of hepatocytes, with activation of both the innate and the acquired immune responses and the induction of chronic inflammation, accompanied by metabolic alterations that imply the accumulation of lipids in the liver (hepatic steatosis). The identified deregulated genes may be useful as biomarkers of environmental pollution.

Samples were collected from the middle and lower reaches of the Yangtze River, China, to study the concentrations, distributions, and compositions of 16 US-EPA priority polycyclic aromatic hydrocarbons (PAHs) in water and suspended particulate matter (SPM). We also evaluated sources of the PAHs and their potential toxicity. Total concentrations of the PAHs (ΣPAHs) in water ranged from 17.33 to 77.12 ng L⁻¹, and in SPM, the levels ranged from 595.91 to 2473.74 ng g⁻¹. Total concentrations of seven carcinogenic PAHs (ΣCPAHs) ranged from 7.63 to 13.02 ng L⁻¹ in water and 276.55 to 1216.89 ng g⁻¹ in SPM. PAH levels in water samples were relatively low, and those in the lower reaches were higher than in the middle reaches. SPM samples had higher levels of PAHs, especially in the lower reaches and in Dongting Lake and Poyang Lake. Principal component analysis (PCA) with multiple linear regression analysis (MLR) was performed to quantitatively characterize the PAH sources. Two factors and their contributions were identified from water samples. Coal and wood combustion accounted for 74.1 % of the PAHs, and petroleum emissions explained 25.9 % of the PAHs. Three source factors were identified from SPM samples: these were vehicular emissions (46.3 % of PAHs), wood and coal combustion (40.4 % of PAHs), and petrogenic sources (13.3 %). Ecological risk assessment indicated that a moderate undesirable impact will be caused by PAHs, and some control measures and remedial actions should be conducted.

Thyroid hormones play a fundamental role in the regulation of metabolism of almost all mammalian tissue including the reproductive system. Hyperthyroidism in early life may cause delayed sexual maturation, although physical development is normal and skeletal growth may be accelerated. Hyperthyroidism after puberty influences reproductive functions and increases testosterone level. The aim of this work is to study the effect of induced hyperthyroidism by L-thyroxine sodium administration on the testis of rats and to evaluate the ameliorating role of different antioxidants as ascorbic acid and folic acid on the hyperthyroid state via the assessment of different biochemical markers, histopathological and immunochemical sections. DNA analysis of the D1 deiodinase was performed to determine genetic mutation due to hyperthyroidism. The results showed partially disrupted in the measured biochemical parameters and spermatogenesis in hyperthyroid rats. Post-administration of both folic and ascorbic acids together in hyperthyroid rats showed the best ameliorating effects on the thyroid hormones, testosterone, testicular GGT and ALP, and all oxidative stress markers. There is no genetic mutations that occurred in D1 deiodinase due to hyperthyroidism. These findings were indicated by the proliferating cell nuclear antigen (PCNA) studies of testes.