Pharmaceutical antibiotics have recently become emerging environmental contaminants. To enhance the removal efficiency of antibiotics in water, hierarchically porous carbons (HPCs) with designed porous patterns are used in both batch and column mode adsorption processes in this study, and the role of their nanoporous geometry in the adsorption dynamics are explored. THPC (HPC with trimodal pores) and DHPC (HPC with bimodal pores) exhibit remarkably superior adsorption performances to the selected antibiotics than those of commercial activated carbon (AC) with similar surface area, especially in column mode adsorption. The effective treatment volumes of the HPC-columns remain up to 8–10 times those of the AC-columns for the removal of tetracycline and 4–6 times for the removal of tylosin. The mass transfer rates of the carbon-based columns present the order of THPC > DHPC > AC. As comparison, the columns based on monomodal mesoporous carbon (MEC) and microporous carbon (MAC) exhibit low effective treatment volumes although their high mass transfer speed. The interconnected meso/macropores in HPCs benefit the intraparticle mass transfer of guest molecules and the accessibility of adsorption sites. The micropores linking to the meso/macropores not only provide adsorption sites but also facilitate adsorption affinity.

Exposure to household air pollution (HAP) from solid fuel use (SFU) causes millions of premature deaths globally. Direct leakage from stoves into indoor air is believed to be the main cause of severe HAP. However, previous laboratory-based measurements reported leakage of minimal fractions from wood fuel combustion. Using a newly developed measurement method, on-site measurements were conducted to quantitatively evaluate the leakage of gases and particulate matter from different fuel-stove combinations. The fraction of indoor leakage to the total emission (F) of the measured air pollutants varied from 23 ± 11% to 40 ± 16% for different pollutants and fuel-stove combinations, and these were significantly higher than previously lab-based results. Fuel differences overwhelmed stove differences in influencing F values, with higher values from biomass burning than from coal combustion. The particles had higher F values than gases. Fugitive emission rates (ERs) were log-normally distributed, and biomass burning had higher ERs than coal burning. Indoor PM₂.₅ (fine particulate matter) and CO (carbon monoxide) concentrations measured during the burning period increased by nearly 1–2 orders of magnitude compared to concentrations before or after burning, confirming substantially high indoor leakage from fuel combustion in cookstoves. High fugitive emissions in indoor cookstoves quantified from the present on-site measurements effectively explain the high HAP levels observed in rural SFU households, and call for interventions to improve indoor air quality.

Chloropicrin (CP) controls soil-borne plant diseases caused by pathogenic microbes, increases crop yield, but has a long-term inhibitory effect on beneficial soil microorganisms. Therefore, we evaluated the effects of biofumigation material fresh chicken manure (FCM) on soil microorganisms, and the duration of those effects in this experiment. Our results showed that in the laboratory, FCM significantly increased substrate-induced respiration (SIR) of soil microorganisms by 2.2–3.2 times at 80 d compared to the control, however, CP significantly inhibited the SIR of soil microorganisms. FCM and CP increased NH4+-N concentration within 40 days which then returned to the control level. FCM increased NO3--N by 2.82–5.78 times by 80 days, compared with the control, while the concentration of NO3--N in the CP treatment was not significantly different from the control at the 80 day. Although in the laboratory FCM inhibited the relative abundance of 16 S rRNA and the nitrogen cycle functional genes AOA amoA, AOB amoA, nirK and nosZ over a 40-day period, the taxonomic diversity of soil bacteria and fungi in the FCM treatment were restored to unfumigated level within 90 days in the field. However, CP treatment has a strong inhibitory effect on soil microorganisms after 90 days. Importantly, the relative abundance of some beneficial microorganisms that control soil-borne pathogenic microbes or degrade pollutants increased significantly in FCM, including Bacillus, Pseudomonas and Streptomyces bacterial genera and Chaetomium and Mycothermus fungal genera. Noteworthy, like CP, FCM still had a strong inhibitory effect on Fusarium at 90 d. Our results indicated that FCM not only increased the content of inorganic nitrogen and improved the respiration rate of soil microorganisms, but it also shortened the recovery time of beneficial soil microorganisms and increased taxonomic diversity. Our previous reports showed that FCM and CP treatments had the same effect in disease control and crop growth. Combined with the results of this experiment, we believe that FCM has the potential to replace CP, which would eliminate CP's detrimental environmental impact, improve farmer safety and promote sustainable crop production.

Phosphorus (P) cycling present in sediments associated with iron (Fe), manganese (Mn) and sulfur (S) geochemical processes may cause secondary pollution in overlying water. Understanding the mechanisms of P release from sediments should help to restore water quality. This study used the diffusive gradients in thin film (DGT) technique to investigate the seasonal variation in the lability, remobilization mechanisms, and release characteristics of sediment P in the uncontaminated Xizhi River and the severely contaminated Danshui River, South China. P accumulation in sediments contributed to higher DGT-labile P concentrations in contaminated reaches, and the highest labile P concentrations were generally observed in summer season at each site. The significant positive relationships (p < 0.05) between labile Fe and P confirmed the Fe–P coupling release mechanism in uncontaminated sediments. Stronger relationships between labile Mn and P at contaminated sites indicated that Mn oxides played an important role in P remobilization. However, sulfate reduction associated with microbial activities (crucial genera: Desulfobulbus, Desulfomicrobium and Desulforhabdus) was considered to decouple the Fe & Mn–P cycling relationship, promoting P release at contaminated sites. The effluxes of sediment P were much higher in the Danshui River (mean 0.132 mg cm⁻²·d⁻¹) than in the Xizhi River (mean 0.038 mg cm⁻²·d⁻¹). And hot season led to growth in P effluxes that was much greater in contaminated river.

Chlorinated paraffins (CPs) are pervasive environmental pollutants which have been reported to be hepatotoxic by laboratory cell and animal studies. However, the related epidemiological reports on their hepatotoxic effects to humans are sparse. In this study, we evaluated the associations between six liver enzymes and serum short-chain CP (SCCP) or medium-chain CP (MCCP) concentrations of 197 residents in Jinan, China. Serum S/MCCPs were detected by quadrupole time-of-flight high-resolution mass spectrometry coupled with atmospheric pressure chemical ionization source (APCI-QTOF-HRMS), and quantified by pattern deconvolution method. The associations between total serum S/MCCP concentrations (ΣS/MCCPs) and continuous liver enzyme levels were assessed by linear regression. Odds ratios (ORs) for the effects of serum ΣS/MCCPs concentrations on liver function biomarkers dichotomized by clinical reference intervals were predicted by logistic regression, either treating ΣS/MCCPs as continuous or categorical dependents. After multivariable adjustment, linear regression results illustrated that 1-ln unit increase in serum ΣSCCPs was negatively associated with male PA levels [-6.08, 95% confidence interval (CI): −11.90, −3.25, p < 0.05], positively associated with male TB levels (1.80, 95% CI: 0.28, 3.31, p < 0.05), and positively associated with female AST levels (1.39, 95% CI: 0.07, 2.70, p < 0.05). One-ln unit increase in serum ΣMCCPs was negatively associated male PA levels (−7.56, 95% CI: −17.15, −4.03, p < 0.05). Logistic regression results suggested that male serum ΣSCCPs were associated with increased prevalence of abnormal PA (OR = 1.47 per 1 ln-unit increase, CI = 1.18, 1.82) and TB (OR = 1.75, 95% CI = 1.12, 2.76) levels, and male serum ΣMCCPs were significantly associated with increased prevalence of abnormal PA (OR = 1.43, 95% CI = 1.03, 1.97) levels. In addition, male participants with concentrations above the median ΣS/MCCPs were associated with increased risk for abnormal PA levels [SCCPs, 2.11-fold (95% CI = 1.15, 3.87); MCCPs, 1.94-fold (95% CI = 1.24, 3.03)]. Male participants with concentrations above the median ΣSCCPs were also associated with increased risk for abnormal TB levels (OR = 1.75, 95% CI = 1.12, 2.76). Conclusively, our results revealed that CP internal exposure was associated with disturbed liver biomarker levels, suggesting the hepatotoxicity of both SCCPs and MCCPs to humans.

It remains unclear how the source and rate of nitrogen (N) fertilizers affect N₂O concentration and effluxes along the soil profile under the drip-fertigated agricultural system. A plot-based field study was performed in 2017 and 2018 in a cotton field in arid northwestern China, with an objective to elucidate the impact of the applications of conventional urea (Urea), polymer-coated urea (ESN) and stabilized urea (SuperU) at rates of 120 and 240 kg N ha⁻¹ on concentration and efflux of N₂O in the soil profile and its relationship with N₂O surface emissions. The in-situ N₂O concentrations at soil depths of 5, 15, 30 and 60 cm were measured and used to estimate soil profile N₂O effluxes. Estimates of surface N₂O flux using the concentration gradient-based (GM) were compared with those measured using the chamber-based (CM) method. In both years, soil N₂O concentrations at all depths increased in response to basal N application at planting or in-season fertigation events. However, N rate or source did not affect soil N₂O concentrations or effluxes at each depth. Surface emissions of N₂O were mostly associated with that presented in the top layer of 0–15 cm. Surface N₂O efflux determined by GM was poorly or not associated with those of chamber measurements, which was attributed to the low N₂O production restricted by soil moisture condition under the drip-fertigated condition. These results highlight the challenge of applying the enhanced efficiency N fertilizer products in the drip-fertigated agricultural system.

Though many studies pertaining to soil bioremediation have been performed to study the microbial kinetics in shake flasks, the process efficiency in column tests is seldom. In the present study, soil columns tests were carried out to study the biodegradation of soil contaminated with a high concentration of diesel (≈19.5 g/kg) petroleum hydrocarbons expressed as C₁₀–C₅₀. Experiments were done with crude enzymatic cocktail produced by the hydrocarbonoclastic bacterium, Alcanivorax borkumensis. A. borkumensis was grown on a media with 3% (v/v) motor oil as the sole carbon and energy source. The effects of the enzyme concentration, treatment time and oxidant on the bioremediation efficiency of C₁₀–C₅₀ were investigated. A batch test was also carried out in parallel to investigate the stability of the enzymes and the effect of the biosurfactants on the desorption and the bioconversion of C₁₀–C₅₀. Batch tests indicated that the biosurfactants significantly affected the desorption and alkane hydroxylase and lipase enzymes, maintained their catalytic activity during the 20-day test, with a half-life of 7.44 days and 8.84 days, respectively. The crude enzyme cocktail, with 40 U/mL of lipase and 10 U/mL of alkane hydroxylase, showed the highest conversion of 57.36% after 12 weeks of treatment with a degradation rate of 0.0218 day⁻¹. The results show that the soil column tests can be used to optimize operating conditions for hydrocarbon degradation and to assess the performance of the overall bioremediation process.

Calcium peroxide (CaO₂) has been proven to oxidize various organic pollutants when they exist as a single class of compounds. However, there is a lack of research on the potential of unactivated CaO₂ to treat mixed chlorinated organic pollutants in soils. This study examined the potential of CaO₂ in treating soils co-contaminated with p-dichlorobenzene (p-DCB) and p-chloromethane cresol (PCMC). The effects of CaO₂ dosage and treatment duration on the rate of degradation were investigated. Furthermore, the collateral effects of the treatment on treated soil characteristics were studied. The result showed that unactivated CaO₂ could oxidize mixed chlorinated organic compounds in wet soils. More than 69% of the pollutants in the wet soil were mineralized following 21 days of treatment with 3% (w/w) CaO₂. The hydroxyl radicals played a significant role in the degradation process among the other decomposition products of hydrogen peroxide. Following the oxidation process, the treated soil pH was increased due to the formation of calcium hydroxide. Soil organic matter, cation exchange capacity, soil organic carbon, total nitrogen, and certain soil enzyme activities of the treated soil were decreased. However, the collateral effects of the system on electrical conductivity, available phosphorus, and particle size distribution of the treated soil were not significant. Likewise, since no significant release of heavy metals was seen in the treated soil matrix, the likelihood of metal ions as co-pollutants after treatment was low. Therefore, CaO₂ can be a better alternative for treating industrial sites co-contaminated with chlorinated organic compounds.