We evaluated ecological monitoring data and landowner perceptions to the federally funded Wetlands Reserve Program (WRP) in a three-county region in Wisconsin. We surveyed landowner satisfaction, involvement, participation, and use of the WRP restoration sites. We found that landowners are satisfied with the overall program (mean, 3.6 ± 0.2 [SE], on a scale of 1–5, with 5 being completely satisfied). WRP restorations significantly increased the area of wetland within the sites surveyed, the increase was primarily of fresh meadow (736.32 ha after restoration). Satisfaction is related to landowner participation during restoration and to the economic incentives provided by the WRP, Landowner satisfaction and the number of plant communities after restoration are unrelated to each other or to restoration and easement costs per hectare. Survey participants recommended some changes to the WRP, including a reduction in the tax rate of land enrolled in the WRP, approval for permanent deer stands, and increased communication with WRP officials during the restoration. Monitoring information collected for WRP restoration sites does not allow assessment of whether WRP sites are functionally equivalent to natural sites. We suggest that the WRP require a more rigorous monitoring program, including guidelines for invasive species control. Managers should also encourage collaborations with external researchers and consider restorations within an experimental framework. 相似文献
When the hazard quotient for ingestion (HQI) of a trace element in soil and dust particles is adjusted for the element’s bioaccessibility, the HQI is typically reduced as compared to its calculation using pseudo-total element concentration. However, those studies have mostly used bulk particles (<2 mm or <250 µm), and the reduction in HQI when expressed as bioaccessible metal may not be similar among particle size fractions, the possibility probed by the present study of street dusts and soils collected in Tehran. The highest Cu, Pb and Zn near-total concentrations occurred in the finest particles of dusts and soils. Bioaccessible concentrations of Cu, Pb and Zn in the particles (mg kg?1) were obtained using simple bioaccessibility extraction test (SBET). The bioaccessibility (%) did not vary much among near-total concentrations. In the bulk (<250 µm) sample, the bioaccessible concentration of Cu and Pb increased as the pH of sample increased, while Zn bioaccessibility (%) in the bulk particles was influenced by organic matter and cation exchange capacity. X-ray diffraction identified sulfide and sulfate minerals in all of the size-fractionated particles, which are insoluble to slightly soluble in acidic conditions and included most of the Cu and Pb in the samples. The only Zn-bearing mineral identified was hemimorphite, which would be highly soluble in the SBET conditions. The calculated HQI suggested potential non-carcinogenic health risk to children and adults from ingestions of soils and dusts regardless of particle size consideration, in the order of Zn > Pb ≥ Cu. The HQI calculated from near-total metal was not much different for particle size classes relative to bulk particles; however, the bioaccessibility percent-adjusted HQI for Pb was higher for the smaller particles than the bulk. This work is novel in its approach to compare HQI for a bulk sample of particles with its composite particle size fractions. 相似文献
Membranes and filters made of nanofibers can have many medicines and water treatment applications. The use of silver nanoparticles (AgNPs) with antibacterial activity in these structures improve their efficiency. However, due to the toxicity of the compounds used in the chemical synthesis of AgNPs, in this study, AgNPs were obtained through a biological process using Fusarium sporotrichioides. AgNPs preparation conditions were optimized, including F. sporotrichioides medium and AgNO3 concentration. Next, a PVA nanofiber membrane with bentonite and AgNPs (Bio-AgNPs or Chem-AgNPs) was prepared using electrospinning. The optimal conditions for the production of Bio-AgNPs were the culture of F. sporotrichioides in the MGYP culture medium and 12 M of AgNO3. The Bio-AgNPs particle size and zeta potential were 58 nm and ??16.8 mV, respectively, with antibacterial activity. The PVA/NB/AgNPs nanofibers operation conditions included 7.5% w/w PVA, 3% w/w bentonite, and AgNPs 5% w/w at a voltage of 11 kV, feed rate of 0.5 mL/h, and 15 cm distance between the needle and the collector. The average diameter of the PVA/NB/Bio-AgNPs nanofibers was 230 nm. Also, the presence of silver in the nanofibers was confirmed through EDX and XRD methods. The antibacterial assay of the nanofibers showed that the inhibition zone of PVA/NB/Bio-AgNPs against E. coli and S. aureus was 0.62 and 0.36 mm, which is better than PVA/NB/Chem-AgNPs and comparable with chloramphenicol. The produced membrane is suitable for water treatment, food packaging, and wound dressing because of its good thermal, mechanical, and antibacterial properties.