The objective of this experiment was to evaluate the effects of Triton X-100 (1000 mg kg⁻¹) and nano-SiO₂ (500 mg kg⁻¹) on Erigeron annuus (L.) Pers. grown in phenanthrene spiked soil (150 mg kg⁻¹) for 60 days. Results show that untreated groups, groups treated with both Triton X-100 and nano-SiO₂, exhibited better phenanthrene degradation rates and improved root biomasses, chlorophyll contents, and soil enzyme activities. This study demonstrates that Triton X-100 combined with nano-SiO₂ protects plants, alleviating the stress of polycyclic aromatic hydrocarbons (PAHs), and can provide a means for improving phytoremediation of PAH contaminated soils.

This study investigated the feature of phosphorus uptake by low-cost waste concrete. Adsorption isotherms, metal dissolution, influence of P concentration and temperature, as well as adsorbent regeneration were investigated. Chemical extraction, SEM, XRD, FTIR, and XPS were employed to determine the products of P sequestration. Results demonstrated that phosphate adsorption fitted the Langmuir isotherm model well, with estimated maximum phosphate adsorption capacity of 80.5 mg/g (10 °C). Of adsorbed phosphate, 72.1% could be desorbed when 0.1 M citrate buffer was used as eluant, and waste concrete could be recovered and reused for 4 times by the combination of eluting and roasting. Mechanisms including Ca/alkali dissolution, surface adsorption, and chemical precipitation are involved in the sequestration of phosphorus from wastewater by waste concrete. Weakly adsorptive phosphorus and Ca-P precipitate were the main products. P concentration was the major factor that affected P removal capacity and the product types, while temperature had certain effect at low P concentration. The dominant product was weakly adsorptive phosphorus for low P concentration at low temperature, which was substituted by Ca-P precipitate as temperature or P concentration increased. The increase of P concentration assisted both the increase of P removal potential and the formation of Ca-P precipitate to crystal DCPD.

Sediment toxicity plays a fundamental role in the health of inland fish communities; however, the assessment of the hazard potential of contaminated sediments is not a common objective in environmental diagnostics or remediation. This study examined the potential of transcriptional endpoints investigated in zebrafish (Danio rerio) exposed to riverbed sediments in ecotoxicity testing. Embryo-larval 10-day tests were conducted on sediment samples collected from five sites (one upstream and four downstream of the city of Milan) along a polluted tributary of the Po River, the Lambro River. Sediment chemistry showed a progressive downstream deterioration in river quality, so that the final sampling site showed up to eight times higher concentrations of, for example, triclosan, galaxolide, PAH, PCB, BPA, Ni, and Pb, compared with the uppermost site. The embryo/larval tests showed widespread toxicity although the middle river sections evidenced worse effects, as evidenced by delayed embryo development, hatching rate, larval survival, and growth. At the mRNA transcript level, the genes encoding biotransformation enzymes (cyp1a, gst, ugt) showed increasing upregulations after exposure to sediment from further downstream sites. The genes involved in antioxidant responses (sod, gpx) suggested that more critical conditions may be present at downstream sites, but even upstream of Milan there seemed to be some level of oxidative stress. Indirect evidences of potential apoptotic activity (bcl2/bax < 1) in turn suggested the possibility of genotoxic effects. The genes encoding for estrogen receptors (erα, erβ1, erβ2) showed exposure to (xeno)estrogens with a progressive increase after exposure to sediments from downstream sites, paralleled by a corresponding downregulation of the ar gene, likely related to antiandrogenic compounds. Multiple levels of thyroid disruption were also evident particularly in downstream zebrafish, as for thyroid growth (nkx2.1), hormone synthesis and transport (tg, ttr, d2), and signal transduction (trα, trβ). The inhibition of the igf2 gene reasonably reflected larval growth inhibitions. Although none of the sediment chemicals could singly explain fish responses, principal component analysis suggested a good correlation between gene transcripts and the overall trend of contamination. Thus, the combined impacts from known and unknown covarying chemicals were proposed as the most probable explanation of fish responses. In summary, transcriptional endpoints applied to zebrafish embryo/larval test can provide sensitive, comprehensive, and timeliness information which may greatly enable the assessment of the hazard potential of sediments to fish, complementing morphological endpoints and being potentially predictive of longer studies.

One of the most important ecological processes is the formation of interspecific relationships in relation to spatial patterns among alpine cushion plants in extreme environmental habitats. However, such relationships remain poorly understood. Here, we examined the spatial patterns of alpine cushion plants along an altitudinal gradient of environmental severity and the interspecific relationship between two cushion species (Thylacospermum caespitosum and Androsace tangulashanensis) on the eastern Kunlun Mountain of China. Our results showed that the two species were highly aggregated within a distance of 2.5–5 m at the mid (S2) altitude, whereas they were randomly distributed at the low (S1) and high (S3) altitudes. A positive spatial interaction between the two species was observed over shorter distances at the mid (S2) altitude, and the spatial patterns were related to the size of individuals of the two species. Moreover, the impact of A. tangulashanensis on T. caespitosum (RIIT. cₐₑₛₚᵢₜₒₛᵤₘ) was negative in all the study plots, and a positive impact of T. caespitosum on A. tangulashanensis (RIIA. ₜₐₙgᵤₗₐₛₕₐₙₑₙₛᵢₛ) was only observed at the mid (S2) altitude. Together, these results demonstrated that the spatial patterns of these two cushions varied with environmental severity, since the outcome of the interactions were different, to some extent, at the three altitudes. Plant size is the main factor affecting the spatial correlation and interspecific relationship between two cushions. Therefore, its potential influence should be considered when discussing interspecific relationships among cushions and their community construction at small scales in alpine ecosystems.

Accretion of heavy metals in forage is a potential risk to grazing animals due to their uptake by plants and its entrance into the food chain. This study aimed to examine the Mn and Cd concentration from different samples. Sampling was done twice after the interval of 6 months during 2018; five different sites from Chakwal (Pidh, Tobar, Ratoccha, Kalar Kahar Road, Choa Saiden Shah and Chakwal Road, Choa Saiden Shah) were selected. Thirty samples of soil, forage (Acacia nilotica, Ziziphus nummularia, and Acacia modesta), and blood were collected. Forage and soil samples were dried, ground very fine, digested by wet digestion method, and analyzed by atomic absorption spectrophotometer. Samples collected from site I and site II had a very high concentration of heavy metals because these sites were very close to the coal mines and receive higher contamination. Manganese concentration in the soil fluctuated from 5.46 to 1.20, in the forage 6.84 to 1.00, and in the blood 5.21 to 1.03 mg/l, and cadmium concentration in the soil fluctuate from 1.85 to 0.03, in the forage 0.57 to 0.16, and in the blood 1.67 to 0.25 mg/l. Manganese concentration was higher as compared to the Cd. Higher concentration of Mn shows that this metal is due to human activities. Pollution load index value of Cd was higher than 1 in some samples, and the value fluctuates from 0.01 to 1.24 mg/kg. The values of a bioconcentration factor for Mn were greater than 1. Daily intake of metal value fluctuates from 0.01 to 1.03 mg/kg. Health risk index value ranges from 0.03 to 1.09 mg/kg. Health risk index of metals showed the risk which is due to the intake of contaminated fodder. From the soil, the metals can enter forage and bioaccumulate in the food chain. The health risk index was highest for Cd. The result obtained from the present research work indicated that there is a biomagnification of both metals in the food chain due to mining activities.

China’s rapid social and economic development has led to a significant deterioration in the water environment, which has limited sustainable regional development. Therefore, understanding the specific factors that affect the water environment is vital for future water conservation efforts. From a social economy perspective, this paper used population, the economy, urbanization, technological level, water consumption, and other factors to expand the STIRPAT model, after which partial least squares was applied to solve the model parameters and comprehensively analyze the impact of regional development on the water environment in Sichuan Province from 2007 to 2017. It was found that the main factors affecting the water environment were resident population, urbanization, service industry development, and industrialization, with the industrialization factor being found to have a reverse waste-sewage water discharge inhibition. In addition, it was found that during the study period, there was no environmental Kuznets curve between water resource environmental pollution and economic growth in Sichuan Province. Finally, some policy recommendations for improving the water environment were given based on the results.

Municipal solid waste (MSW) management and recycling has become an emerging issue in developing countries. Shanghai, the largest megacity in China, is well-known nationwide due to leading China’s MSW separation and recycling. Therefore, this paper introduces the Shanghai mode for MSW management and its current situation to enrich existing MSW management studies. Results show that the total generation volume of MSW and amount of MSW generation per capita were 9.00 million tons and 372.16 kg in 2017, increased approximately eight-fold and four-fold compared with the data in 1978, respectively. The MSW treatment rate reached 100% since 2014, with incineration rate increased to 48.56% in 2017. The cost of MSW management after implementing MSW sorting regulation is increased to 985 CNY/ton, including 390 CNY/ton of MSW sorting cost. Then three key features and innovative MSW management modes, namely, mandatory MSW sorting legislation, Green Account program, and the Combined Network program are introduced. Meanwhile, two main challenges are urgent to be responded, including inadequate collecting vehicles and limited wet waste treatment capacity. Finally, policy recommendations on strengthening MSW recycling process, constructing complete terminal treatment industry, and making systematic policies were provided to respond existing challenges.

This paper reports the treatment of gaseous hydrogen sulfide, H₂S, in a biotrickling filter (BTF) under extreme acidic pH conditions (≈ 1.2). The effect of adding thiosulfate (Na₂S₂O₃.5H₂O) to promote biomass growth, feeding low concentrations of ozone to control excess biomass, and the carbon dioxide, CO₂, consumption by the chemolithoautotrophic consortium were evaluated. The results showed a global removal efficiency over 98.0% with loads of H₂S > 50 g m⁻³ h⁻¹ (at 639 ppmv) and a linear relation between H₂S elimination capacity with the CO₂ consumption rate of around 0.1 gCO₂/gH₂S. Supplementing sulfur in the medium with 2 g L⁻¹ thiosulfate resulted in negative effect performance. Respirometry tests proved that the consortium could not utilize this sulfur form at this pH. Additionally, continuous and intermittent O₃ feeding to the BTF in gaseous concentrations of 98 ± 5.4 mg m⁻³ caused a slight decreased in the performance but the biomass activity in the BTF was only slightly affected allowing a quick performance recovery once O₃ addition was suspended.

High temperature melting treatment and cement solidification are technologies currently used to reduce the leaching of heavy metals in municipal solid waste incinerator (MSWI) fly ash. In this paper, to ascertain the feasibility of melting MSWI fly ash with blast furnace (BF) slag, ultra-risk MSWI(U-MSWI) fly ash having high heavy metal (Zn, Pb, Cu, and Cr) contents were blended with BF slag, then melted and quenched into water to prepare reconstructed slag. The melting and solidification behaviors, phase composition and microstructure, and heavy metal leachability of reconstructed slag were studied. In addition, to study the further solidification and utilization of reconstructed slag in cement, the compressive strength and leaching concentration of cement composites with reconstructed slag were also investigated. The results indicate that the presence of heavy metals in the U-MSWI fly ash had a little influence on the microstructure and phase composition of reconstructed slag. The leaching concentration of heavy metals in the reconstructed slag increased with the increasing of U-MSWI fly ash content, and when the content of U-MSWI fly ash was less than 50 wt%, the reconstructed slag could meet the environmental requirements. The reconstructed slag further solidified by cement could be applied to landfill and construction materials. The technology of melting reconstruction treatment with cement solidification was a technical-economical choice for the industrial treatment of U-MSWI fly ash.