Navigating the nexus: climate dynamics and microplastics pollution in coastal ecosystems.

Microplastics (MPs) pollution is an emerging environmental health concern, impacting soil, plants, animals, and humans through their entry into the food chain via bioaccumulation. Human activities such as improper solid waste dumping are significant sources that ultimately transport MPs into the water bodies of the coastal areas. Moreover, there is a complex interplay between the coastal climate dynamics, environmental factors, the burgeoning issue of MPs pollution and the complex web of coastal pollution. We embark on a comprehensive journey, synthesizing the latest research across multiple disciplines to provide a holistic understanding of how these inter-connected factors shape and reshape the coastal ecosystems. The comprehensive review also explores the impact of the current climatic patterns on coastal regions, the intricate pathways through which MPs can infiltrate marine environments, and the cascading effects of coastal pollution on ecosystems and human societies in terms of health and socio-economic impacts in coastal regions. The novelty of this review concludes the changes in climate patterns have crucial effects on coastal regions, proceeding MPs as more prevalent, deteriorating coastal ecosystems, and hastening the transfer of MPs. The continuous rising sea levels, ocean acidification, and strong storms result in habitat loss, decline in biodiversity, and economic repercussion. Feedback mechanisms intensify pollution effects, underlying the urgent demand for environmental conservation contribution. In addition, the complex interaction between human, industry, and biodiversity demanding cutting edge strategies, innovative approaches such as remote sensing with artificial intelligence for monitoring, biobased remediation techniques, global cooperation in governance, policies to lessen the negative socioeconomic and environmental effects of coastal pollution.

Heavy metal pollution near an abandoned mercury-bearing waste recovery enterprise in southwestern China: Spatial distribution and its sources in soil and plants.

The contribution of smelting of nonferrous metals to heavy metals in surface soil have become increasingly important over the past decade. In this study, the distribution of heavy metals around an abandoned mercury-bearing waste recovery enterprise were investigated. Soil (14) and plant (18) samples were collected in the surrounding area. The total concentration of heavy metals and methyl mercury content were measured by ICP-MS and HPLC-ICP-MS. The results show that the average contents of Cd, Cr, Pb, Hg and As in all soil samples are higher than the second-level values of Soil environmental quality-Risk control standard for soil contamination of development land (GB 36600-2018). Hg in the leaves ranged from 0.003 to 0.174 mg kg-1. Besides, the Pearson correlation analysis results indicate that Hg has a different environmental behavior compared to the other heavy metal under certain environmental or geographical conditions. But the mantel test statistical analysis results show that the Cr (P < 0.01), Cu, Pb, and Fe (P < 0.05) in the soil may have similar pollution sources with carbonate-bound mercury and iron-manganese oxide-bound mercury. The Hg concentrations show no correlation among plant leaves and soil, but significantly influenced by the distance and wind direction. These findings suggest that Hg in plant leaves may be derived from the deposition of atmospheric mercury from secondary mercury plant. The results will supplement those for relevant policy making for mercury-bearing waste recovery enterprises to improve urban environmental quality and human health.

Environmental iodine as a natural iodine intake in humans and environmental pollution index: a scientometric and updated mini review.

Although almost a third of the world's population is exposed to iodine deficiency (ID), and supplementation programs such as enriching table salt have been carried out or are being carried out at the global and national level, in many regions of the world, people are facing an increase in iodine intake, which is mainly due to the presence of large amounts of iodine in water, soil, agricultural products, or high consumption of seafood. Published articles were indexed in the Scopus database (from 2000 to 1 April 2023) were reviewed and analyzed by VOSviewer software. The results showed the growing interest of researchers over the last 20 years in environmental iodine intake. The results of this study can have a significant impact on the planning and policy-making of relevant officials and communities to supply the needed iodine.

Pollution indices of selected metals in tea (Camellia sinensis L.) growing soils of the Upper Assam region divulge a non-trifling menace of National Highway.

The study investigated the influence of a National Highway (NH) traversing tea estates (TEs) on heavy metal (HM) contamination in the top soils of Upper Assam, India. The dispersion and accumulation of six HMs, viz. cadmium (Cd), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), and zinc (Zn), within tea-growing soils were assessed using diverse indices: contamination factor (CF), degree of contamination (DC), enrichment factor (EF), geo-accumulation index (Igeo), modified degree of contamination (MDC), Nemerow pollution index (PINemerow), pollution load index (PLI), potential ecological risk factor (Eri), and potential ecological risk index (RI). The order of HM prevalence was Fe > Mn > Zn > Ni > Cu > Cd. Elevated Cd levels near the NH prompted immediate attention, while Cd and Zn showed moderate pollution in CF, EF, and RI. The remaining metals posed minimal individual risk (Eri< 40), resulting in an overall contamination range of "nil to shallow," signifying slight contamination from the studied metals. From MDC values for investigated metals, it was found to be "zero to very low degree of contamination" at all locations except the vicinity of NH. Soil pollution, as determined by PLI, indicated unpolluted soils in both districts, yet PINemerow values indicated slight pollution. The statistical analysis revealed that there is a significant decrease in most of the indices of HM as the distance from NH increases. The application of multivariate statistical techniques namely Principal Component Analysis and Cluster Analysis showed the presence of three distinct homogenous groups of distances based on different indices. This investigation underscores NH-associated anthropogenic effects on TE soil quality due to HM deposition, warranting proactive mitigation measures.

Respiratory Health Effects of Pollution Due to Artisanal Crude-Oil Refining in Bayelsa, Nigeria.

Purpose: Artisanal refining of crude oil has been associated with the manifestations of various health problems directly related to the release of particulate matter, including polycyclic aromatic hydrocarbons (PAHs), into the environment. This study thus assessed the respiratory health effects associated with being resident in areas where crude oil is artisanally refined in Bayelsa State. Material and methods: This study utilized a comparative, cross-sectional design and was conducted in three communities in Bayelsa State. These included Sampou (a mildly exposed community), Nembe, and Gbarain (severely exposed communities). A sample population of 615 adults selected by multistage sampling completed the study instrument, which assessed data on their respiratory health. Environmental monitoring of the PAHs levels of the samples was done, and concentrations were determined using the gas chromatography/flame ionization detector (GC/FID). The Statistical Package for Social Sciences version 25 was used to conduct descriptive and inferential analyses. Results: Findings revealed that the highest number of moderate to severe respiratory disease symptoms was experienced by respondents from Nembe 12 (41.4%), followed by those from Sampou 8 (27.6%), and then by those from Gbarain 9 (31.0%). Also, coughing that occurred mostly when lying down was found to be significantly prevalent among residents of Nembe [35 (47.9%); p-value: 0.016], among other symptoms. Respiratory disease symptoms were more likely to be found among females (p-value: 0.037), smokers (p-value: 0.002), and those having a low health risk perception related to PAHs exposure (p-value: 0.002). Conclusion: Respondents from the three study sites had in the past 12 months experienced various respiratory disease symptoms, which could be directly related to their exposure to pollution from artisanal crude oil refining. Artisanal refining of crude oil should be continually dissuaded through unwavering enforcement of environmental health laws in order to further improve public and environmental health.

Analysis of soil pollution characteristics and influencing factors based on ten electroplating enterprises.

The electroplating industry encompasses various processes and plating types that contribute to environmental pollution, which has led to growing public concern. To investigate related soil pollution in China, the study selected 10 sites with diverse industrial characteristics distributed across China and collected 1052 soil samples to determine the presence of industrial priority pollutants (PP) based on production process and pollutant toxicity. The factors influencing site pollution as well as proposed pollution prevention and control approaches were then evaluated. The results indicate the presence of significant pollution in the electroplating industry, with ten constituents surpassing the risk screening values (RSV). The identified PP consist of Cr(VI), zinc (Zn), nickel (Ni), total chromium (Cr), and petroleum hydrocarbons (C10-C40). PP contamination was primarily observed in production areas, liquid storage facilities, and solid zones. The vertical distribution of metal pollutants decreased with soil depth, whereas the reverse was true for petroleum hydrocarbons (C10-C40). Increase in site production time was strongly correlated with soil pollution, but strengthening anti-seepage measures in key areas can effectively reduce the soil exceedance standard ratio. This study serves as a foundation for conceptualizing site repair technology in the electroplating industry and offers a reference and methodology for pollution and source control in this and related sectors.

Characteristics of PM2.5-bound metals in Japan over six years: Spatial distribution, health risk, and source analysis.

Air sampling campaigns were conducted at 100 survey sites across Japan from April 2014 to February 2020, and a comprehensive database of atmospheric particles was obtained. In this study, the characteristics of PM2.5 and 26 metals were investigated in depth. Spatially, the concentration of PM2.5 gradually increased from the northeast to the southwest of Japan. The pollution in Kitakyushu City was the most serious, reaching 19.8 µg m-3. As an important particle component, metals did not show obviously spatial variation in Japan, with a sum concentration of 0.4 µg m-3. Anthropogenic metals only accounted for about 8% of the total metals, but they could pose a serious threat to public health. For children, the non-carcinogenic risk and carcinogenic risk due to exposure to anthropogenic metals could not be neglected in Japan; the corresponding HI and CR values at 100 survey sites ranged from 2.7 to 15.0 and 4.1 × 10-5 to 3.4 × 10-4, respectively. Adults faced lower health risks than children, with HI values ranging from 0.2 to 2.0 and CR values ranging from 2.0 × 10-5 to 1.6 × 10-4. The integrated health risk assessment results showed that the coastal region of the Seto Inland Sea and the north Tohoku Region were the most heavily polluted areas of Japan; in this study, 20 survey sites were finally determined to be high-risk sites, among which pollution control for Niihama City, Kitakyushu City, Hachinohe City, and Shimonoseki City were of first priority. With further combination with a positive matrix factorization model, it can be known that these four cities mainly had five to seven metal sources, and their heavy pollution was mainly caused by ship emissions, industrial emissions, biomass burning, and coal combustion. Overall, our study comprehensively revealed the regional patterns of PM2.5-bound metal pollution across Japan, which can help in making cost-effective risk management policies with limited national/local budgets.

Environmental pollution and nutritional quality modulate immune response of the wood mouse (Apodemus sylvaticus) through hormonal disturbances.

Cadmium (Cd) and lead (Pb) are known to enhance immune cell damages and to decrease cellular immunity, promoting higher susceptibility to infectious diseases. Selenium (Se) is an essential element involved in immunity and reactive oxygen species scavenging. This study aimed at evaluating how Cd and Pb and low nutritional (Se) quality modulate immune response to a bacterial lipopolysaccharide (LPS) challenge in wood mice (Apodemus sylvaticus). Mice were trapped near a former smelter in northern France in sites of High or Low contamination. Individuals were challenged immediately after capture or after five days of captivity, fed a standard or a Se-deficient diet. Immune response was measured with leukocyte count and plasma concentration of TNF-α, a pro-inflammatory cytokine. Faecal and plasma corticosterone (CORT), a stress-hormone involved in anti-inflammatory processes, was measured to assess potential endocrine mechanisms. Higher hepatic Se and lower faecal CORT were measured in free-ranging wood mice from High site. LPS-challenged individuals from High site showed steeper decrease of circulating leukocytes of all types, higher TNF-α concentrations, and a significant increase of CORT, compared to individuals from Low site. Challenged captive animals fed standard food exhibited similar patterns (decrease of leukocytes, increase of CORT, and detectable levels of TNF-α), with individuals from lowly contaminated site having higher immune responses than their counterparts from highly polluted site. Animals fed Se-deficient food exhibited lymphocytes decrease, no CORT variation, and average levels of TNF-α. These results suggest (i) a higher inflammatory response to immune challenge in free-ranging animals highly exposed to Cd and Pb, (ii) a faster recovery of inflammatory response in animals lowly exposed to pollution when fed standard food than more exposed individuals, and (iii) a functional role of Se in the inflammatory response. The role of Se and mechanisms underlying the relationship between glucocorticoid and cytokine remain to be elucidated.

[Pollution Characteristics and Risk Assessment of PAHs in the Soil of Wild Forsythia Suspensa in Shanxi].

Shanxi is one of the main producing areas of Forsythia suspensa in China. In order to explore the safety of the soil in the areas where Forsythia suspensa grows,70 surface (0-25 cm) soil samples were collected from the main growing areas of F. suspensa in the eastsouth of Shanxi Province in July 2017. The concentration and composition characteristics of 16 polycyclic aromatic hydrocarbons (PAHs) in the sample soils were analyzed using chemical extraction and gas chromatography-mass spectrometry (GC-MS). The diagnostic ratio method was used to determine the source of PAHs in the areas. The potential ecological risk was assessed by using the method of calculating the equivalent carcinogenic concentration of benzo[a]pyrene. The results showed that the average concentration of total PAHs (Σ16PAHs) in all of the soil samples was 1.85 µg·g-1, which was dominated by three ring number PAHs, accounting for 76.7% of the total PAHs. The detection rates of phenanthrene (Phe) and anthracene (Ant) were both 100% of all the sample sites. The soil PAHs in the wild F. suspensa growing areas mainly originated from coal, biomass burning, and motor vehicle exhaust emissions, which resulted from air transport and sedimentation pathways. In all of the sample sites, the concentration of Σ16PAHs the limit standard level (0.2 µg·g-1) of Maliszewska-Kordybach for agricultural soil pollution and exceeded the soil heavy pollution level limit value (1.0 µg·g-1) in 41.4% of the sample sites. The concentration of BaP was above the risk control standard for soil contamination of agricultural land (0.55 µg·g-1) in 10% of all the soil samples. A total of 11.4% of the sample soil ΣBaPeq16PAHs and ΣBaPeq8BPAHs exceeded the agricultural soil screening value (0.55 µg·g-1). These results indicate that the contamination of PAHs was at a detectable level in the soil of wild F. suspensa growing in Shanxi, and thus their potential ecological risks should not be ignored. It is necessary to enhance the research regarding these areas to ensure the safe production of medicinal plants.

Application of KHSO5 for remediation of soils polluted by organochlorides: A comprehensive study on the treatment's efficacy, environmental implications, and phytotoxicity.

Soil pollution caused by complex organochloride mixtures has been increasing in many parts of the world in recent years; as a result, countless numbers of people are exposed to dangerous pollutions; hence, the treatment of organochlorides-polluted soils is gaining considerable attention. In this study, the potential of unactivated peroxymonosulfate (KHSO5) in remediating soil co-contaminated with trichlorophenol, para-dichlorobenzene, and para-chloro-meta-cresol was investigated. In addition, the treatment's collateral effect on critical soil properties was explored. The result revealed that treating 10 g of soil with 20 mL of 5 mM KHSO5 for 60 min could oxidize 70.49% of the total pollutants. The pH of the soil was decreased following the treatment. The significant decrease, (p < 0.05), in the soil organic matter following the remediation has affected cation exchange capacity, and available nitrogen. It was also observed that the treatment reduced the ß-glucosidase, urease, invertase, and cellulase activities significantly, (p < 0.05). The treatment, on the other hand, brought negligible effects on available phosphorus, available potassium, and particle size distribution. The phytotoxicity tests, which included seed germination and root elongation and soil respiration tests revealed that the treatment did not leach toxins into the treated soil. The treatment method was found to be relatively ecofriendly and cost effective.

Pollution impact assessment of secondary iron smelting on soil and some medicinal herbs grown at Fasina community in Ile-Ife, Nigeria.

Use of medicinal herbs is now gaining popularity especially among the low-income people because it is cheap, readily available and its "seeming" lack of side effects. However, environmental pollution is a potential threat to its continued use. This study examines the effect of air pollution on the soil and consequently on the medicinal herbs grown on such soils. Soil and four medicinal herbs, Chromolaena odorata, Vernonia amygdalina, Carica papaya and Ocimum gratissimum, commonly used in the south western part of Nigeria either as purely medicinal herbs, soup vegetables or both were carefully harvested from Fasina, a polluted area, and Moro, a relatively unpolluted area, all in Ile-Ife, Nigeria. Samples were prepared following standard practice and analysed for nickel, chromium, cadmium and lead using atomic absorption spectroscopy (AAS). The results showed that elemental concentrations at the two locations were within the permissible limit for both soil and herbs, the statistical test also established no significant difference between the two locations. However, toxic metals concentrations (chromium, cadmium and lead) were found higher at the polluted site while that of the essential metal, nickel, was higher at the unpolluted site. Of the four metals, cadmium has the highest transfer ratio (0.39 and 0.34) while lead has the least (0.21 and 0.25) for Moro and Fasina sites respectively. Similarly, Chromolaena odorata has the highest transfer ratio (0.34) while Carica papaya has the least (0.28). In conclusion, gradual build-up of the toxic metals at the polluted site is evident and may eventually contaminate the herbs.

Mechanochemical treatment of hexachlorobenzene-contaminated soil with additives.

The use of mechanochemistry for the remediation of hexachlorobenzene (HCB)-contaminated soil was investigated. Additives such as alkaline materials, neutral materials, natural minerals, and solid waste were studied to explore their effect on the degradation of hexachlorobenzene in soil with single or combined addition by mechanochemical method. The best combination of materials were determined based on HCB destruction percentage by considering the impact on soil quality, the treatment cost, and the availability of additives. Scanning electron microscope (SEM) images and X-ray photoelectron spectrometer (XPS) analysis were conducted for the mechanism studies. The combination of albite and ferric oxide (Fe3O4) was found to achieve the best performance in the degradation of HCB with the destruction percentage from 74.3 to 92.5% after 2-h and 6-h reaction, respectively. The developed fracture structure and complex compositions of albite provided abundant reaction sites for mechanochemical degradation of HCB in soil.

Effects of thermal desorption on ecotoxicological characteristics of heavy petroleum-contaminated soil.

This study comprehensively evaluates the ecotoxicity of high-concentration heavy petroleum (HCHP)-contaminated soil before and after thermal desorption (TD) remediation at different temperatures and times. The results showed that the detoxification of contaminated soil was effectively achieved by extending the remediation duration at 400-600 °C. After treatment at 400 °C for 60 min, the toxicological indicators including bioluminescence EC50 (acute toxicity), seed germination ratio (Gr) and plant biomass of Brassica juncea (subacute toxicity), and diversity of the microbial community (chronic toxicity) reached a maximum. The value of the SOS-Induction Factor (SOSIF), characterizing genotoxicity was below 1.5, indicating that it was non-toxic. Pearson's correlation analysis illustrated that the water-soluble fraction (WSF), ALK1-3 and ARO1-3 of petroleum hydrocarbons were the primary sources of ecotoxicity. Notably, although the total ratio of petroleum removed from the soil reached 87.26 ± 4.38 %-98.69 ± 1.61 % under high-temperature thermal desorption (HTTD, 500-600 °C), the ecotoxicity was not lower than that at 400 °C. The pyrolysis products of petroleum macromolecules and extreme changes in soil properties were the leading causes of soil ecotoxicity following HTTD. The inconsistency between the removal of petroleum pollutants and ecological health risks reveals the significance of soil ecotoxicological assessments for identifying TD remediation endpoints and process optimization.

Using pollution indices to develop a risk classification tool for gold mining contaminated soils.

The presence of potentially toxic elements (PTEs) in soil and plants is a risk factor to human well-being and the environment. Soil and leaves from a traditional medicinal plant, Vachellia karroo, known as the sweet thorn plant, were assessed to determine the extent of pollution by PTEs from gold mine tailings in a case study area of Matjhabeng Local Municipality, South Africa. A risk classification tool was developed using the different indicators of pollution quantified to describe the pollution risk at each sampling site. High concentrations of copper, cadmium, lead, nickel, and zinc were measured in the soil, which exceeded the maximum permissible soil quality limits. The enrichment factor and geoaccumulation index results also confirmed heavy soil pollution by copper, nickel, and zinc, with exceptionally heavy pollution by cadmium and selenium. The PTEs in the soil were in an exchangeable form, with the sweet thorn plant accumulating lead and selenium at toxic levels, which poses a risk to the health of the local people as the plant is used for medicinal purposes. The overall pollution risk classification tool of the sampling sites showed that 17% were high-risk areas, 53% were moderate-risk areas, and 20% of the sites were low-risk areas.

Identification priority source of soil heavy metals pollution based on source-specific ecological and human health risk analysis in a typical smelting and mining region of South China.

An in-depth understanding of the ecological and health risks posed by heavy metals originating from various pollution sources is critical for foresighted soil-quality management. Based on 220 grid samples (2 × 2 km) analyzed for eight heavy metals (Cd, Hg, As, Pb, Cr, Ni, Cu, and Zn) in the Chenshui (CS) watershed of Hunan Province, China, we applied an integrated approach for identifying and apportioning pollution sources of soil heavy metals and exploring their source-specific pollution risks. This approach consists of three sequential steps: (1) source identification by combining the positive matrix factorization model with geostatistical analysis; (2) quantification of ecological, carcinogenic, and non-carcinogenic risks in a source-specific manner; (3) prioritization of sources in a holistic manner, considering both ecological risks and human health risks. Cd (68.0%) and Hg (13.3%) dominated the ecological risk in terms of ecological risk index; As dominated the non-carcinogenic health risk in terms of total hazard index (THI; adults: 84.8%, children: 84.7%) and the carcinogenic health risk in terms of total carcinogenic risk index (TCRI; adults: 69.0%, children: 68.8%). Among three exposure routes, oral ingestion (89.4-95.2%) was the predominant route for both adults and children. Compared with adults (THI = 0.41, TCRI = 7.01E-05), children (THI = 2.81, TCRI = 1.22E-04) had greater non-carcinogenic and carcinogenic risks. Four sources (F1-4) were identified for the CS watershed: atmospheric deposition related to coal-burning and traffic emissions (F1, 18.0%), natural sources from parent materials (F2, 34.3%), non-ferrous mining and smelting industry (F3, 37.9%), and historical arsenic-related activity (F4, 9.8%). The F3 source contributed the largest (45.2%) to the ecological risks, and the F4 source was the predominant contributor to non-carcinogenic (52.4%) and carcinogenic (64.6%) risks. The results highlight the importance of considering legacy As pollution from abandoned industries when developing risk reduction strategies in this region. The proposed methodology for source and risk identification and apportionment formulates the multidimensional concerns of pollution and the various associated risks into a tangible decision-making process to support soil pollution control.

Impact of FDI, crude oil price and economic growth on CO2 emission in India: - symmetric and asymmetric analysis through ARDL and non -linear ARDL approach.

The paper examines the impact of macroeconomic variables on CO2 emissions, very few research studies are available to estimate the asymmetric impact and causality. Because of the significance of asymmetries, this paper examines the asymmetric impact of economic growth, crude oil use, and FDI inflows on CO2 emissions in the India wherein COP (Crude oil price) is comprised as the extra variable. The implicate aggressive growth of selected variables over the period 1990-2020 is also assessed. This study uses the methodology ARDL and NARDL model to determine the macroeconomics variable's effects on CO2 emission over the period 1990-2020. Additionally, also applied the EKC (Environmental Kuznets Curve) hypothesis with an application of ARDL and NARDL model. With help of the ARDL and NARDL model, the study shows the results that a rise in economic growth would reduce CO2 (carbon dioxide) emissions while a decrease in economic growth would raise CO2 emissions which indicates an inverted U-shaped Curved relationship between economic growth and CO2 emissions. The positive and negative shockwaves in COP (crude oil prices) have a satisfactory and substantial impact on CO2 emissions as well. Besides, the crude oil consumption with positive shockwave confirmations has a positive and substantial impact on CO2 emission. In addition, the results of FDI inflows support the pollution heaven hypothesis. In light of these outcomes, this paper also recommended policy implications and future research, the policy implications are where the descending flow of FDI allows limited space to India in FDI selection; however, the existence of emission merging and implementation of carbon pricing may facilitate India in achieving its environmental targets.

Systematic study on dynamic pyrolysis behaviors, products, and mechanisms of weathered petroleum-contaminated soil with Fe2O3.

Weathered petroleum-contaminated soil (WPCS) with a high proportion of heavy hydrocarbons is difficult to remediate. Our previous research demonstrated that Fe2O3-assisted pyrolysis was a cost-effective technology for the remediation of WPCS. However, the pyrolysis behaviors, products, and mechanisms of the WPCS with Fe2O3 are still unclear. In this study, a combination of Thermogravimetric-Fourier transform infrared spectroscopy (TG-FTIR) and pyrolysis gas chromatography/mass spectrometry (Py-GC/MS) techniques were used to explore these pyrolysis characteristics. The thermal desorption/degradation of light and heavy hydrocarbons in the WPCS mainly occurred at 200-400 °C and 400-550 °C, respectively. The activation energy of thermal reaction of heavy hydrocarbons was decreased in the presence of Fe2O3 during the WPCS pyrolysis processes. In the process, the released inorganic gaseous products were mainly H2O and CO2, while the released organic gaseous compounds were primarily cycloalkanes, alkanes, acids/esters, alcohols, and aldehydes. Compared with the WPCS pyrolysis without Fe2O3, the yields of gaseous products released during the WPCS pyrolysis with Fe2O3 were reduced significantly, and some gaseous products were even not detected. This phenomenon was contributed by the following two reasons: 1) heavy hydrocarbons in the WPCS were more easily transformed into coke in the presence of Fe2O3 during pyrolysis; 2) some released gaseous products were reacted with Fe2O3 and fixed on the soil particles. Therefore, the WPCS pyrolysis with Fe2O3 can effectively reduce the burden of tail gas treatment. Criado method analysis results suggested that the reaction mechanism of heavy hydrocarbons during the WPCS pyrolysis with Fe2O3 was rendered as the synergic effects of diffusion, order-based, and random nucleation and growth reactions.

Characteristics of overflow pollution from combined sewer sediment: Formation, contribution and regulation.

Sewer sediments contain high concentrations of carbon, nitrogen, and phosphorus pollutants, which can be the main source of overflow pollution due to high-velocity scouring. To elucidate the scouring overflow pollution characteristics and regulation mechanism of sewer sediment under different precipitation intensities, a sewer-storage tank linkage control experimental device was established to simulate the practical sewer overflow under different precipitation intensities and the control process of storage tank overflow pollutants. Based on the division of flow from small to large, the pollution characteristics of overflow pollutants and the contribution rate of sewer sediments to overflow pollutants were analysed. The results showed that the total load of overflow pollutants increased with an increase in rainfall intensity and were 7.58 kg, 16.54 kg, 27.42 kg, respectively. The concentration of particulate pollutants increased sharply in a short time, and the concentration of dissolved pollutants decreased at a certain dilution. Sewer sediment was the main source of overflow pollutants, contributing up to 70%. After the overflow pollutants entered the regulation and storage tank, a certain stratification phenomenon was discovered at different sedimentation times. The concentration of large particle pollutants gradually increased from top to bottom in the regulation and storage tank, and the concentration of dissolved pollutants showed no obvious difference between the layers. With an increase in rainfall intensity, the recommended regulation and storage times of overflow pollutants were within 15 min, 45-60 min, and 60 min, respectively. Finally, based on the relationship among rainfall intensity, sediment scouring thickness, regulation and storage time, a prediction formula for the regulation and storage time of overflow pollutants was obtained, which provided a basis for the regulation and treatment of subsequent overflow pollutants.

A typical case study from smelter-contaminated soil: new insights into the environmental availability of heavy metals using an integrated mineralogy characterization.

Mineralogy was an important driver for the environmental release of heavy metals. Therefore, the present work was conducted by coupling mineral liberation analyzer (MLA) with complementary geochemical tests to evaluate the geochemical behaviors and their potential environmental risks of heavy metals in the smelter contaminated soil. MLA analysis showed that the soil contained 34.0% of quartz, 17.15% of biotite, 1.36% of metal sulfides, 19.48% of metal oxides, and 0.04% of gypsum. Moreover, As, Pb, and Zn were primarily hosted by arsenopyrite (29.29%), galena (88.41%), and limonite (24.15%), respectively. The integrated geochemical results indicated that among the studied metals, Cd, Cu, Mn, Pb, and Zn were found to be more bioavailable, bioaccessible, and mobile. Based on the combined mineralogical and geochemical results, the environmental release of smelter-driven elements such as Cd, Cu, Mn, Pb, and Zn were mainly controlled by the acidic dissolution of minerals with neutralizing potential, the reductive dissolution of Fe/Mn oxides, and the partial oxidation of metal sulfide minerals. The present study results have confirmed the great importance of mineralogy analysis and geochemical approaches to explain the contribution of smelting activities to soil pollution risks.

[Analysis of heavy metal pollution in Lonicerae Japonicae Flos and its health risk assessment].

In this study, the content of five heavy metals(Pb, Cd, As, Hg, and Cu) in 59 batches of Lonicerae Japonicae Flos(LJF) medicinal materials and pieces were determined by inductively coupled plasma mass spectrometry(ICP-MS). The health risk assessment was processed using the maximum estimated daily intake(EDI), target hazard quotients(THQ), and carcinogenic risks(CR) assessment models. With reference to the limit standard for heavy metal content in LJF specified in 2020 edition of Chinese Pharmacopoeia, five batches produced in Hebei were found to contain excessive Pb, and the remaining 54 batches met the specifications, with the unqualified rate of 8.47%. Comparative analysis of heavy metal content in LJF samples from three different producing areas, namely Shandong, Henan, and Hebei showed that the levels of Pb, As, and Hg in LJF from Hebei were significantly higher than those from Henan and Shandong. The samples produced in Shandong contained the highest content of Cd. The samples from Hebei contained the highest content of Cu while those from Shandong had the lowest content of Cu. As demonstrated by health risk assessment based on the EDI, THQ and CR models, these 59 batches of LJF samples did not cause significant health hazards for the exposed population, and there was no potential non-carcinogenic or carcinogenic risk. In conclusion, a few of LJF samples contained excessive heavy metals, so some measures, including controlling production environment, cultivating management mode, and optimizing processing methods, should be taken for ensuring the medication safety of LJF.