This work describes the synthesis, characterization, and application of an active heterogeneous photo-Fenton system obtained from two different wastes, i.e., laterite (an iron mining waste) and the acid aqueous fraction (AAF) from bio-oil production. AAF with high acidity (ca. 3 molH₊ L⁻¹) and organic concentration (25 wt.%) obtained from biomass flash pyrolysis was used for the efficient extraction of Fe³⁺ from laterite waste. After extraction, the mixture Fe³⁺/AAF was dried and treated at different temperatures, i.e., 500, 650, and 800 °C, to obtain Fe/C reactive composites. Mössbauer, XRD, TG, elemental analyses, and SEM/EDS showed the presence of highly disperse Fe oxide nanoparticles at 500 and 650 °C and Fe⁰ particles in the material obtained at 800 °C with carbon contents varying from 74 to 80 %. The three composites were tested as heterogeneous catalysts in the photo-Fenton reaction for the oxidation of the model dye contaminant methylene blue, showing high activities at neutral pH.

Because of their significant impact on public health, waterborne pathogens, especially bacteria and viruses, are frequently monitored in surface water to assess microbial quality of water bodies. However, more than one billion people worldwide currently lack access to safe drinking water, and a diversity of waterborne outbreaks caused by pathogens is reported in nations at all levels of economic development. Spatio-temporal distribution of conventional pollutants and five pathogenic microorganisms were discussed for the Haihe River Basin. Land use and socio-economic assessments were coupled with comprehensive water quality monitoring. Physical, chemical, and biological parameters were measured at 20 different sites in the watershed for 1 year, including pH, temperature, conductivity, dissolved oxygen, turbidity, chemical oxygen demand, ammonia-N, total and fecal coliforms, E. coli, and Enterococcus. The results highlighted the high spatio-temporal variability in pathogen distribution at watershed scale: high concentration of somatic coliphages and fecal indicator bacteria in March and December and their very low concentration in June and September. All pathogens were positively correlated to urban/rural residential/industrial land and negatively correlated to other four land use types. Microbial pollution was greatly correlated with population density, urbanization rate, and percentage of the tertiary industry in the gross domestic product. In the future, river microbial risk control strategy should focus more on the effective management of secondary effluent of wastewater treatment plant and land around rivers.

The seasonal variation and removal efficiency of antibiotic resistance genes (ARGs), including tetracycline resistance genes (tetG, tetM, and tetX) and macrolide (ermB, ermF, ereA, and mefA), were investigated in two typical swine wastewater treatment systems in both winter and summer. ARGs, class 1 integron gene, and 16S rRNA gene were quantified using real-time polymerase chain reaction assays. There was a 0.31–3.52 log variation in ARGs in raw swine wastewater, and the abundance of ARGs in winter was higher than in summer. tetM, tetX, ermB, ermF, and mefA were highly abundant. The abundance of ARGs was effectively reduced by most individual treatment process and the removal efficiencies of ARGs were higher in winter than in summer. However, when examining relative abundance, the fate of ARGs was quite variable. Anaerobic digestion reduced the relative abundance of tetX, ermB, ermF, and mefA, while lagoon treatment decreased tetM, ermB, ermF, and mefA. Sequencing batch reactor (SBR) decreased tetM, ermB, and ermF, but biofilters and wetlands did not display consistent removal efficiency on ARGs in two sampling seasons. As far as the entire treatment system is concerned, ermB and mefA were effectively reduced in both winter and summer in both total and relative abundance. The relative abundances of tetG and ereA were significantly correlated with intI1 (p < 0.01), and both tetG and ereA increased after wastewater treatment. This may pose a great threat to public health.

Chlorella vulgaris was cultivated under limitation and starvation and under controlled conditions using different concentrations of nitrate (NaNO₃) and phosphate (K₂HPO₄ and KH₂PO₄) chemicals in modified Bold basal medium (BBM). The biomass and lipid production responses to different media were examined in terms of optical density, cell density, dry biomass, and lipid productivity. In the 12-day batch culture period, the highest biomass productivity obtained was 72.083 mg L⁻¹ day⁻¹ under BBM - NcₒₙₜᵣₒₗPₗᵢₘᵢₜₑd condition. The highest lipid content, lipid concentration, and lipid productivity obtained were 53.202 %, 287.291 mg/L, and 23.449 mg L⁻¹ day⁻¹ under BBM - NCₒₙₜᵣₒₗPDₑₚᵣᵢᵥₐₜᵢₒₙ condition, respectively. Nitrogen had a major effect in the biomass concentration of C. vulgaris, while no significant effect was found for phosphorus. Nitrogen and phosphorus starvation was found to be the strategy affecting the lipid accumulation and affected the lipid composition of C. vulgaris cultures.

The environmental catastrophic accidents in China over the last three decades have triggered implementation of myriad policies by the government to help abate environmental pollution in the country. Consequently, research into environmental pollution liability insurance and how that can stimulate economic growth and the development of financial market in China is worthwhile. This study attempts to design a financial derivative for China’s environmental pollution liability insurance to offer strong financial support for significant compensation towards potential catastrophic environmental loss exposures, especially losses from the chemical industry. Assuming the risk-free interest rate is 4%, the market portfolio expected return is 12%; the financial asset beta coefficient is 0.5, by using the capital asset pricing model (CAPM) and cash flow analysis; the principal risk bond yields 9.4%, single-period and two-period prices are 103.85 and 111.58, respectively; the principal partial-risk bond yields 10.09%, single-period and two-period prices are 103.85 and 111.58, respectively; and the principal risk-free bond yields 8.94%, single-period and two-period prices are 107.99 and 115.83, respectively. This loss exposure transfer framework transfers the catastrophic risks of environmental pollution from the traditional insurance and reinsurance markets to the capital market. This strengthens the underwriting capacity of environmental pollution liability insurance companies, mitigates the compensation risks of insurers and reinsurers, and provides a new channel to transfer the risks of environmental pollution.

In this work, a multi-class analytical method for determination of 22 frequently used pharmaceuticals was developed and validated. Analytes were from different classes for example macrolides, fluoroquinolones, tetracyclines, sulfonamides, anthelmintics, anesthetics, and others. Method was intended for analysis of aqueous samples so the sample preparation was done using solid-phase extraction (SPE). Different sorbents (C8, C18, polymeric, and ion exchange sorbents) combining different eluents (methanol, ethanol, acetonitrile, acetone, ethyl acetate) were investigated during development of sample preparation step. Samples were analyzed using HPLC-MS/MS, and therefore, chromatographic and mass spectrometer conditions were investigated. Optimal extraction efficiencies for most of the investigated analytes were obtained with Oasis HLB polymeric sorbents with acetonitrile as eluent. A study of matrix effect was carried out for wastewater treatment plant (WWTP) influent and effluent. The method was validated for linearity, detection limits and quantification limits, repeatability, and reproducibility. Method detection limits were in the range of 2.0–204.0 ng L⁻¹ for WWTP influent except for sulfaguanidine and dexamethasone. Also, method detection limits for WWTP effluent were from 1.0 to 115.4 ng L⁻¹. Method was successfully applied for analysis of real wastewater samples from municipal wastewater treatment plant. In the influent, pharmaceuticals from all investigated groups were present and the concentrations were from 50.0 to 4914.3 ng L⁻¹ for influent and 26.9 to 1699.2 ng L⁻¹ for effluent. It was also reported that some pharmaceuticals showed higher concentrations in the wastewater effluent than in the influent.

Electrotrophic denitrification is a novel nitrogen removal technique. In this study, the performance and the mechanism of electrotrophic denitrification were investigated at different nitrate concentrations and current intensities. The results showed that the performance of electrotrophic denitrification was good with a sludge loading of 0.39 kg N/kg VSS day. The half-saturation constant for nitrate-N was 1894.03 mg/L. The optimal nitrate-N concentration and current intensity were 1500 mg/L and 20 μA, respectively. Electrotrophic denitrification was defined as the process of direct use of electron for nitrate reduction, and electrotrophic denitrifier was proposed to be the microbe of using electricity as energy source directly. The present work will benefit the development and application of electrotrophic denitrification. Graphical abstract ᅟ

High toxicity, bioaccumulation factor and widespread dispersal of persistent organic pollutants (POPs) cause environmental and human health hazards. The combined use of plants and bacteria is a promising approach for the remediation of soil and water contaminated with POPs. Plants provide residency and nutrients to their associated rhizosphere and endophytic bacteria. In return, the bacteria support plant growth by the degradation and detoxification of POPs. Moreover, they improve plant growth and health due to their innate plant growth-promoting mechanisms. This review provides a critical view of factors that affect absorption and translocation of POPs in plants and the limitations that plant have to deal with during the remediation of POPs. Moreover, the synergistic effects of plant–bacteria interactions in the phytoremediation of organic pollutants with special reference to POPs are discussed.

Landfill is known as a potential source of atmospheric Hg and an important component of the local or regional atmospheric Hg budget. This study investigated the gaseous elemental Hg surface–air fluxes under differing conditions at a typical municipal solid waste landfill site, highlighting the interactive effects of plant coverage and meteorological conditions. The results indicated that Hg fluxes exhibited a feature represented by diel variation. In particular, Hg deposition was observed under a condition of Kochia sieversiana coverage, whereas emission that occurred after K. sieversiana was removed. Hg emission was the dominant mode under conditions of Setaria viridis coverage and its removal; however, the average Hg emission flux with the S. viridis coverage was nearly four times lower than after its removal. These findings verified that the plant coverage should be a key factor influencing the Hg emission from landfills. In addition, Hg fluxes were correlated positively with solar radiation and air/soil temperature and correlated inversely with relative humidity under all conditions, except K. sieversiana coverage. This suggested that the interactive effects of meteorological conditions and plant coverage played a jointly significant role in the Hg emission from landfills. It was established that K. sieversiana can inhibit Hg emission efficiently, and therefore, it could potentially be suitable for use as a plant-based method to control Hg pollution from landfills.

The present study measured concentrations of Cr, Ni, Cu, Zn, As, Cd, Sb, and Pb in surface sediments and two benthic invertebrate species (Anodonta woodiana and Bellamya aeruginosa) collected from Dianshan Lake, located in the Yangtze River Delta. The Dianshan Lake acts as one of the most important drinking water sources to Shanghai, the biggest city in China. Concentrations of trace metals and metalloids ranged from 0.04 mg/kg for Cd to 288.0 mg/kg for Zn. Substantial bioaccumulation in invertebrates was observed for Zn and Cu based on the biota-sediment accumulation factor (BSAF) measurements. The results revealed that concentrations of metals and metalloids in sediments from Dianshan Lake were at the lower end of the range of levels found in other regions of China. The assessment of three significantly inter-related evaluation indices, including the geo-accumulation Index (Igₑₒ), potential ecological risk factor (Erⁱ), and mean probable effect concentration quotients (Qₘ₋PEC), suggested that sediment-associated trace elements exhibited no considerable ecological risks in the studied watershed. However, the target hazard quotient and hazard index analysis suggested that selected elements (particularly As) accumulation in edible tissues of benthic invertebrates could pose potential health risks to local populations, especially fishermen. Given that wild aquatic organisms (e.g., fish and bivalves) constitute the diet of local populations as popular food/protein choices, further investigations are needed to better elucidate human health risks from metal and metalloid exposure via edible freshwater organisms.