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1.
Natural steroidal estrogens, such as 17 β-estradiol (E2), as well as antimicrobials such as doxycycline and norfloxacin, are excreted by humans and hence detected in sewage sludge and biosolid. The disposal of human waste products on agricultural land results in estrogens and antibiotics being detected as mixtures in soils. The objective of this study was to examine microbial respiration and E2 mineralization in sewage sludge, biosolid, and soil in the presence and the absence of doxycycline and norfloxacin. The antimicrobials were applied to the media either alone or in combination at total rates of 4 and 40 mg kg?1, with the 4 mg kg?1 rate being an environmentally relevant concentration. The calculated time that half of the applied E2 was mineralized ranged from 294 to 418 days in sewage sludge, from 721 to 869 days in soil, and from 2,258 to 14,146 days in biosolid. E2 mineralization followed first-order and the presence of antimicrobials had no significant effect on mineralization half-lives, except for some antimicrobial applications to the human waste products. At 189 day, total E2 mineralization was significantly greater in sewage sludge (38 ±0.7%) > soil (23 ±0.7%) > biosolid (3 ±0.7%), while total respiration was significantly greater in biosolid (1,258 mg CO2) > sewage sludge (253 mg CO2) ≥ soil (131 mg CO2). Strong sorption of E2 to the organic fraction in biosolid may have resulted in reduced E2 mineralization despite the high microbial activity in this media. Total E2 mineralization at 189 day was not significantly influenced by the presence of doxycycline and/or norfloxacin in the media. Antimicrobial additions also did not significantly influence total respiration in media, except that total CO2 respiration at 189 day was significantly greater for biosolid with 40 mg kg?1 doxycycline added, relative to biosolid without antimicrobials. We conclude that it is unlikely for doxycycline and norfloxacin, or their mixtures, to have a significant effect on E2 mineralization in human waste products and soil. However, the potential for E2 to be persistent in biosolids, with and without the presence of antimicrobials, is posing a challenge for biosolid disposal to agricultural lands.  相似文献   

2.
A soil enrichment culture (SEC) rapidly degraded 96% of 200 mg L?1 neonicotinoid insecticide thiamethoxam (TMX) in MSM broth within 30 d; therefore, its metabolic pathway of TMX, bacterial diversity and plant growth‐promoting rhizobacteria (PGPR) activities of the cultured isolates were studied. The SEC transformed TMX via the nitro reduction pathway to form nitrso, urea metabolites and via cleavage of the oxadiazine cycle to form a new metabolite, hydroxyl CLO‐tri. In addition, 16S rRNA gene‐denaturing gradient gel electrophoresis analysis revealed that uncultured rhizobacteria are predominant in the SEC broth and that 77.8% of the identified bacteria belonged to uncultured bacteria. A total of 31 cultured bacterial strains including six genera (Achromobacter, Agromyces, Ensifer, Mesorhizobium, Microbacterium and Pseudoxanthomonas) were isolated from the SEC broth. The 12 strains of Ensifer adhaerens have the ability to degrade TMX. All six selected bacteria showed PGPR activities. E. adhaerens TMX‐23 and Agromyces mediolanus TMX‐25 produced indole‐3‐acetic acid, whereas E. adhaerens TMX‐23 and Mesorhizobium alhagi TMX‐36 are N2‐fixing bacteria. The six‐isolated microbes were tolerant to 200 mg L?1 TMX, and the growth of E. adhaerens was significantly enhanced by TMX, whereas that of Achromobacter sp. TMX‐5 and Microbacterium sp.TMX‐6 were enhanced slightly. The present study will help to explain the fate of TMX in the environment and its microbial degradation mechanism, as well as to facilitate future investigations of the mechanism through which TMX enhances plant vigor.  相似文献   

3.
The sustainable management of chemicals and their associated wastes—especially legacy stockpiles—is always challenging. Developing countries face particular difficulties as they often have insufficient treatment and disposal capacity, have limited resources and many lack an appropriate and effective regulatory framework. This paper describes the objectives and the approach of the Egyptian–German Twinning Project under the European Neighbourhood Policy to improve the strategy of managing hazardous substances in the Egyptian Environmental Affairs Agency (EEAA) between November 2008 and May 2011. It also provides an introduction to the Republic of Egypt’s legal and administrative system regarding chemical controls. Subsequently, options for a new chemical management strategy consistent with the recommendations of the United Nations Chemicals Conventions are proposed. The Egyptian legal and administrative system is discussed in relation to the United Nations’ recommendations and current European Union legislation for the sound management of chemicals. We also discuss a strategy for the EEAA to use the existing Egyptian legal system to implement the United Nations’ Globally Harmonized System of Classification and Labelling of Chemicals, the Stockholm Convention and other proposed regulatory frameworks. The analysis, the results, and the recommendations presented may be useful for other developing countries in a comparable position to Egypt aspiring to update their legislation and administration to the international standards of sound management of chemicals.  相似文献   

4.
Abstract

The feasibility of using diatomaceous earth (diatomite) as an insecticidal dust was investigated under conditions of high (80%) and low (10%) relative humidity, using the adult red flour beetle, Tribolium castaneum. Tested were diatomite and two lots of a commercial formulation of the same diatomite, containing 0.2% pyrethrins and 1.0% piperonyl butoxide. For comparison, talcum and a talcum‐based commercial formulation, containing the same concentrations of pyrethrins and piperonyl butoxide, were included in the tests. The insects were exposed to 0.08 mg/cm2 of each material tested, equivalent to the label recommendation of 7 lb/acre for the diatomite‐based commercial insecticide. At 10% RH, higher doses of diatomite were also tested. Mortalities were determined at intervals for up to 84 hours.

Diatomite caused no mortalities at the experimental concentration, regardless of RH. At about four times that rate and 10% RH, it caused less than 5% mortality.

At 80% RH, the diatomite‐based product (P. C. P. Act #14074) was significantly more effective than the talcum‐based one (#13074). At 10% RH, however, the latter acted more quickly than the diatomite‐based formulations, but all produced nearly 100% mortality after 68 hours.

The results are discussed in terms of the physical characteristics of diatomite and in terms of the modes of insecticidal actions of diatomite and pyrethrins. It is concluded that diatomite alone, despite its attractiveness to environmental interests, is not likely to become an effective agent for controlling red flour beetles and other pest insects with similar water‐proofing mechanisms.  相似文献   

5.
Environmental Science and Pollution Research - Biochar remediation efficiency could be enhanced through numerous treatments such as acids treatment. Still, there has little work done on...  相似文献   

6.
Soil was spiked with [9-14C]phenanthrene and [1-14C]hexadecane at 50 mg kg−1 and aged for 1, 25, 50, 100 and 250 d. At each time point, the microcosms were amended with aqueous solutions of cyclodextrin (HP-β-CD) at a range of concentrations (0-40 mM). Mineralisation assays and aqueous HP-β-CD extractions were performed to assess the effect of the amendments on microbial degradation. The results showed that amendments had no significant impact on the microbial degradation of either of the 14C-contaminants. Further, HP-β-CD extractions were correlated with the mineralisation of the target chemicals in each of the soil conditions. It was found that the HP-β-CD extraction was able to predict mineralisation in soils which had not been amended with cyclodextrin; however, in the soils containing the HP-β-CD, there was no predictive relationship. Under the conditions of this study, the introduction of HP-β-CD into soils did not enhance the biodegradation of the organic contaminants.  相似文献   

7.
Environmental Science and Pollution Research - Construction and demolition (C&D) waste diminishes scarce land resources and endangers human health and the surrounding environment....  相似文献   

8.
Abstract

Pretreatment of a Drummer‐Catlin soil mixture with granular formulations of carbofuran or trimethacarb enhanced biodegradation of subsequent treatments with the technical formulations. Degradation of carbofuran was enhanced by pretreatments with trimethacarb, and degradation of trimethacarb was enhanced by pretreatments with carbofuran. Bendiocarb degradation was enhanced by pretreatments of soil with carbofuran or trimethacarb. In bioassays with southern corn rootworm larvae, biological activity of carbofuran, trimethacarb, and bendiocarb was rapidly lost in soils pretreated with granular formulations. Pretreatment of soil with granular terbufos did not enhance the biodegradation of subsequent applications of technical terbufos. Several microbial biomass assays showed an increase in specific carbofuran‐degrading bacteria in soils that were pretreated with carbofuran. Bacteria were isolated that could grow on carbofuran and apparently degrade it when present with another carbon source.  相似文献   

9.
This study quantified the masses of 14 pesticides deposited as wet (precipitation) versus dry (gaseous and particle) atmospheric deposition at a research farm in southwestern Manitoba, Canada. The concentration in air of these pesticides was also measured. Total bulk deposition amounts (wet + dry) ranged from 0.009 to 2.3 μg m?2 for the 12 pesticides detected, and for the six pesticides with both wet and dry deposition detections, dry deposition contributed 12–51% of the total deposition over the crop growing season. Although not applied at the site, eight herbicides registered for use in Canada, as well as lindane (γ-HCH), were all frequently detected (92–100%) in the 12 air samples analyzed during the crop growing season, with by-product isomer α-HCH (75%), clopyralid (50%) and atrazine (8%) detected to a lesser extent. The chemical’s physicochemical properties and the relative mean mass of each agricultural pesticide applied in the province of Manitoba and in a 13 km radius were significant parameters in explaining the trends in the concentrations of pesticides detected in our samples. The important contribution of dry deposition to total pesticide deposition warrants greater attention in arid and semi-arid areas such as the Prairie Region of Canada, also because under a changing climate this region is estimated to experience more severe droughts while the more favorable conditions predicted for pest infestations could lead to increased pesticide applications in agricultural and urban areas.  相似文献   

10.
11.
Phytoremediation which is a plant based remediation process is an emerging technology for treating inorganic (heavy metals) as well as organic pollutants. It may also be suitable for remediation of sites co-contaminated with heavy metals and organics which have become more prevalent. A glasshouse experiment was carried out to investigate the effect of 50 and 100 mg kg?1 of copper or 250 and 500 mg kg?1 of pyrene and the combined effect of copper and pyrene on the growth of Brassica juncea together with the uptake and accumulation of copper as well as dissipation of pyrene. Results showed a negative effect of copper–pyrene co-contamination on shoot and root dry matter and an inhibition of copper phytoextraction. Pyrene was significantly decreased in planted and non-planted soils accounting for 90–94% of initial extractable concentration in soil planted with B. juncea and 79–84% in non-planted soil which shows that the dissipation of pyrene was enhanced with planting. The occurrence of copper tended to increase the residual pyrene in planted soil, however in the presence of high concentration of Cu (100 mg kg?1), the residual pyrene concentration in soil were similar to those in unplanted soil. This may suggest that changes in the root physiology or rhizospheric microbial activity resulting from Cu stress could be an impediment to pyrene dissipation. The inhibition of Cu phytoextraction and degradation of pyrene by B. juncea under co-contamination may reduce the viability of phytoremediation in sites containing multiple pollutants.  相似文献   

12.
Environmental Science and Pollution Research - Microbe-assisted phytoremediation provides an eco-friendly and cost-effective approach to reclaim Cd- and Pb-contaminated soils. In this work,...  相似文献   

13.
Environmental Science and Pollution Research - The consumption of fossil energy is the major cause of environmental pollution. Effectively reducing the fossil energy use has important significance...  相似文献   

14.
Environmental Science and Pollution Research - China’s green growth has shown a trend of fluctuation year by year. Simultaneously, Chinese local governments have pursued simple economic...  相似文献   

15.
Wang  Jin  Han  Ping  Zhang  Yanhua  Li  Jinyu  Xu  Linxu  Shen  Xue  Yang  Zhigang  Xu  Sisi  Li  Guangxue  Chen  Feiyong 《Environmental science and pollution research international》2022,29(25):37315-37326
Environmental Science and Pollution Research - The reserve of Tamarix forest, located in Changyi, China, is the only national marine special reserve taking Tamarix as the main object of protection....  相似文献   

16.
Environmental Science and Pollution Research - Phthalates (PAEs) are common endocrine disrupting chemicals (EDCs) that disrupt fetal development. The present study aimed to evaluate the effects of...  相似文献   

17.
Abstract

The effects of temperatures and solar radiation on the dissipation of 14C‐p,p'‐DDT from a loam soil was studied by quantifying volatilization, mineralization and binding. The major DDT loss occurred by volatilization, which was 1.8 times more at 45oC than at ambient temperature (30°C). Mineralization of DDT slowly increased with time but it decreased slightly with increase in temperature. Binding of DDT to soil was found to be less at higher temperatures (35 and 45°C) as compared to ambient temperature. Degradation of DDT to DDE was faster at higher temperatures.

Exposure of non‐sterilized and sterilized soils treated with 14C‐DDT to sunlight in quartz and dark tubes for 6 weeks resulted in significant losses. Volatilization and mineralization in quartz tubes were more as compared to dark tubes. The volatilized organics from the quartz tubes contained larger amounts of p,p'‐DDE than the dark tubes. Further, higher rates of volatilization were found in non‐sterilized soils than in sterilized soils. The results suggest that faster dissipation of DDT from soil under local conditions relates predominantly to increased volatilization as influenced by high temperature and intense solar radiation.  相似文献   

18.
Laboratory toxicity tests are a key component of the aquatic risk assessments of chemicals. Toxicity tests with Myriophyllum spicatum are conducted based on working procedures that provide detailed instructions on how to set up the experiment, e.g., which experimental design is necessary to get reproducible and thus comparable results. Approved working procedures are established by analyzing numerous toxicity tests to find a compromise between practical reasons (e.g., acceptable ranges of ambient conditions as they cannot be kept completely constant) and the ability for detecting growth alterations. However, the benefit of each step of a working procedure, e.g., the random repositioning of test beakers, cannot be exactly quantified, although this information might be useful to evaluate working procedures. In this paper, a growth model of M. spicatum was developed and used to assess the impact of temperature and light fluctuations within the standardized setup. It was analyzed how important it is to randomly reassign the location of each plant during laboratory tests to keep differences between the relative growth rates of individual plants low. Moreover, two examples are presented on how modeling can give insight into toxicity testing. Results showed that randomly repositioning of individual plants during an experiment can compensate for fluctuations of light and temperature. A method is presented on how models can be used to improve experimental designs and to quantify their benefits by predicting growth responses.  相似文献   

19.

With the increasing complication of production and geology conditions, and the increase of mining intensity and depth in coal mine, the coal structure presents varying degrees of deformation. In order to study the influence of uniaxial tension–compression effect on mechanical properties of coal matrix and CH4/CO2 adsorption characteristics, a macromolecular model reflecting the realistic bituminous coal structure was established. Results demonstrate that the influence of tension strain on the microporous structural parameters is greater than that of compression strain, and the tension strain weakens the mechanical properties but enhances the adsorbates adsorption amount. For the pure gases adsorption, there is a negative linear correlation between the total energy and adsorption amount. Additionally, the strain ranging from??0.20 to 0.20, the distribution of punctated adsorbates density develops to that of banded adsorbates density, and the mean adsorption density and saturated adsorption amount increase linearly. For the binary components adsorption (1:1), the CH4 adsorption strength increases while the CO2 adsorption strength slightly decreases. The minimum of total energy decreases in a quadratic polynomial relationship with the strain, and the proportion of van der Waals energy is 75.8–85.5%. Nevertheless, the competitive adsorption and strain have little effect on the potential energy range of the adsorbates. Furthermore, the diffusibility of CO2 molecular layers is relatively good, and the strain enhances the stability of CH4 molecular layers for the saturated binary adsorption. The findings provide essential guidance for the improvement of carbon capture and storage and CO2-enhanced coalbed methane technologies in the deformation area of coal seam.

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20.
Environmental Science and Pollution Research - Urbanization in China has dramatically increased from 39.10 in 2002 to 58.52% in 2017. Studies have discussed the impacts of urbanization and its...  相似文献   

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