Total Environment Research Themes最新文献

Given the complex composition of hospital wastewater and the high risk of initiating disease outbreaks, comprehensive monitoring and treatment of hospital wastewater are required to prevent social and environmental consequences. This study investigated the physicochemical and microbiological characteristics of wastewater from the Benjamin Mkapa Hospital in Dodoma Tanzania. The wastewater from this hospital is treated in a horizontal flow Constructed Wetland (CW) planted with Typha latifolia before being discharged into the environments. Wastewater samples were collected at the CW inlet and outlet from 02nd May 2022 to 25th July 2022. The results shows that the effluent discharged had pH 7.48 ± 0.63, electrical conductivity 2441 ± 623 µS/cm, Total dissolved solids 1305.5 ± 396 mg/L, Total suspended solids 49.17 ± 53.11 mg/L, Turbidity 9.1 ± 14.83 NTU, COD 170.4 ± 40.6 mg/L, BOD₅ 74.8 ± 33.5 mg/L, NO₃-N 45.4 ± 39.97 mg/L and PO₄-P 4.52 ± 2.30 mg/L. The CW removed TSS by 82% and turbidity 94%. COD, BOD and NO₃-N were removed by 48%, 47% and 58% respectively. E. coli concentration in effluent samples ranged from 1.1 × 10¹ CFU/mL to 1.1 × 10² CFU/mL with an average of 1.77logCFU/mL. Average BOD₅/COD ratio was 0.5 and 0.4 for influent and effluent respectively. The effluent contained higher levels of EC, TDS, and PO₄-P than the influent. According to the findings of this study, most of the parameters of wastewater effluent discharged wasn't within the effluent discharge standards.

Abattoirs operations are adjudged as social service that impact the business development/financial status of societies however, it’s release have been implicated as emerging environmental contaminant. Coincidentially, reports on the spread of multiple antibiotics resistant (MAR) potential enterobacteriaceae from abattoir release continues to undulate with some ambiguity. This study determines the Enterobacter species distribution, emerging virulence and multiple antibiotic resistance dynamics in effluents: a countrified spread-hub and implications of abattior release. Using both standard microbiological/molecular biology techniques, abattoir effluent released into the receiving river at Ikpoba-Oha community, Benin City, Edo State, Nigeria was collected at catchment points. A six-weekly grab (once-off) sample was collected between February and April 2019 from Point Source (PS), Confluent Point (CP), 500 m Upstream (UP) and 500 m Downstream (DS) of CP for microbiological and molecular biology processing. Our result revealed that the bacterial density and total heterotrophic count in PS were significantly (p < 0.01) higher than those recorded in UP and DS. The morphological, biochemical and phenotypic characteristics of the presumptive isolates reveals eight Enterobacter spp. with phenotypic virulence determinants including β- heamolysis, gelatinase production, biofilm formation etc amongst isolates. The 16S rRNA gene PCR detection and partial gene sequencing confirmed two strains of Enterobacter cloacae which are deposited as Enterobacter cloacae BIU RASH1 and Enterobacter cloacae BIU RASH7 with genebank ascension numbers of MN577420 and MN581680. These strains antibiotic susceptibility testing reports showed MAR phenotypes on antibiotics ranging from fluoroquinolone, β-lactam, cephalosporin, tetracycline etc, and MAR-index of 0.82. Such observations amongst abattoir effluents isolates implicates abattoir as potential pathogen distribution hub if adequate control steps are not instituted in affected communities. There is therefore need to ensure that wastes from abattoirs are adequately treated to eliminate potential pathogens before discharge into the environmental water resources to prevent potential public health concerns associated with such release.

One of the major problems affecting agricultural productivity is high soil salt content that causes increased reactive oxygen species production affecting membrane stability and cell metabolism. Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous persistent hydrocarbons comprising two or more fused benzene rings that severely affect plant growth. The study was carried out to screen genotypes of chickpea (Cicer arietinum L.) based on responses to the presence of different concentrations of NaCl, Phenanthrene, and a combination of both NaCl and Phenanthrene, which is the first report of chickpea growth under combination of NaCl and Phenanthrene. Four Chickpea genotypes were grown under three concentrations of NaCl and Phenanthrene respectively and combinations of both NaCl and Phenanthrene. A 21 day in-vitro experiment comprised of growing chickpea in petriplates and growth pouches. Morphological parameters were recorded to differentiate susceptible and tolerant genotypes based on the Stress Tolerance Index. MFV was calculated to further evaluate genotypes under different stress conditions. Results revealed that GPF2 and PBG7 have highest and least STI values respectively hence, GPF2 and PBG7 was tolerant and sensitive genotypes respectively towards the individual and combined effect of NaCl and Phenenathrene. Linear regression analysis revealed that root length can be the reliable trait to study the effect of salt stress on chickpea genotypes while GI can be used as reliable trait to study the effect of Phenanthrene stress and combined stress on chickpea genotypes.

The development of comprehensive soil conservation strategies, based on the soil erosion risk, is one of the critical components of sustainable river basin management, especially in tropical mountainous regions. The present study computes the spatially distributed longtime average annual soil loss (A) and sediment yield (SY) and prioritizes the soil erosion risk in a tropical mountain river basin. The Revised Universal Soil Loss Equation (RUSLE) and the sediment delivery distributed model (SEDD) models were coupled in the GIS environment to predict the intra-basin variability of the A and SY of the Karimpuzha River Basin (KRB) of the southern Western Ghats (in Kerala, India). The results indicate that, on an average basis, 9.3 t of soil has been eroded per hectare per year, whereas the SY is 6.3 t ha⁻¹ y⁻¹ (i.e., approximately two-thirds of the gross soil erosion). The SY of the majority (74.2%) of the basin area is low (i.e., ≤5.0 t ha⁻¹ y⁻¹), whereas the soil erosion and transport processes are a major concern in some areas (ca. 6.3 km²). The results imply the significance of land use/land cover, rainfall, and topography in controlling the soil erosion risk of the basin. The study demonstrates the advantages of the delineation of the critical erosion areas, based on the hydrologic response units (HRUs) of the basin, to implement appropriate soil erosion management options for conservation of the soil resources.

Trace metal leachate comes from inactive mine reservoirs in the study area. The main intention of the study was to analyze the metal content in groundwater samples around inactive mines in the southwest of the Cuddapah Basin and to assess the risk to the local habitants based on calculations using several statistical methods. In this context, the study emphasizes the use of an integrated heavy metal pollution approach, ecological risk assessment incorporating potential health risks, and a multivariate statistical approach at an inactive mining site in the southwestern Cuddapah Basin in southern India. In 2019, we collected 100 samples from bore wells in both pre & post monsoon seasons and ten heavy metals (As, Co, Cd, Fe, Cr, Ni, Mn, Pb, Zn, and Sr) were analyzed using an Agilent 725 ICP-OES instrument. The results showed that As (0–60.5 and 0–56.3 µg/L), Cd (0–28.1 and 0–31.1 µg/L), Ni (0–110.2 and 0–99 µg/L), Pb (0––175.6 and 0–92.3), Sr concentration (0–1150 and 0–1440 μg/L) exceeded permissible values ​​in both seasons. Heavy metal pollution index (HPI), heavy metal evolution index HEI, and pollution degree DOC are used to evaluate the metal pollution of drinking water in this area. As per the HPI values, 17.5 % and 10% of samples show a high pollution index; as per the classes of HEI, 95 % and 100% of samples show a low pollution class during both seasons. According to DOC, all groundwater samples fall in the low contamination zone. As per ecological risk classification, 90% of the samples cause extreme to high ecological risk in both seasons in the study area. From the perspective of health risk assessment, both adults and children have non-carcinogenic effects in the study area; and adequate remedial procedures or treatments are required to avoid metal pollution of groundwater.m.

The concentrations of metals were determined seasonally to assess the probable risk on the local population due to ingestion of metals via the groundwater in an iron mining impacted area of Jharkhand in India. The results depicted significant spatial and temporal variation in the concentration of metals with the highest values during the pre-monsoon season and in the locations with active mining activities. Fe and Mn exceeded the drinking water quality standards in about 75% of the samples considering all the seasons. The metals in the groundwater can be ascribed to both geogenic sources and anthropogenic causes as depicted from principal component analysis, which resulted in extraction of four factors explaining 68.1% of data variance. The hazard quotients (HQ) of the metals calculated for the human health risk assessment according to USEPA methodology suggested that the metals individually did not pose risk to the local population since the HQ of the metals did not exceed unity. However, collective risk of the metals as calculated by the Hazard Index (HI) suggested that the groundwater of most of the locations is unfit for drinking predominantly in the pre monsoon season. The child residents were more susceptible to non-carcinogenic risk than the adult population. The HI for the child population was estimated to be greater than one (1.16) in the pre monsoon season suggesting health risk for vulnerable child populace. The risk was higher in the pre monsoon season as compared to other seasons.

Antibiotics, considered a “wonder medication” in the 20th century, have been exploited to such an extent that bacteria have developed resistance against them giving rise to highly resistant superbugs, which are able to survive in the presence of a medicine that is designed to stop them from growing. The study elucidates the classification and molecular mechanisms of resistance methods employed by bacteria against different generations of antibiotics with their classes, examples and resistant strains. The overuse, misuse and underuse of several antibiotic classes and their improper disposal/treatment in various industries including agriculture, poultry, veterinary and healthcare has led to the generation of antibiotic resistance in many species of bacteria at a higher rate. The causes, drivers, consequences, and the environmental impact of antibiotic resistance also addressed. This is a major global concern amid the recent rise in infectious diseases caused by antibiotic resistant bacterial pathogens and calls for effective, newer generations of antibiotics and better alternative treatments. If we fail to combat antibiotic resistance, death tolls due to small infections would rise which would further lead to social, economic, environmental and medical losses. This paper highlights the pressing need to curb the overuse of antibiotics to prevent antibiotic resistance, advocates for regulation, awareness programs about AMR and the barriers to further discovery.

Reusing sewage water for crop irrigation becomes necessary due to freshwater scarcity, and groundwater depletion. Although the suitability of using treated sewage for crop irrigation remains a topic of argument among government authorities and policymakers. In light of this, this review article summarizes the present global situation and techniques for recycling and application of treated sewage water in agriculture. This paper highlights the environmental, health, and economic impacts of using wastewater as crop irrigation water, along with the advantages and disadvantages are carefully considered. The main objective of this study is to present a global scenario of treated wastewater being used to irrigate agricultural crops, along with the hazards associated with soil fertility, crop production, public health, and economic factors. This study compiled information on the best sewage treatment for agricultural irrigation disinfection practices. Eventually, database of laws and rules governing the use of sewage or wastewater in agricultural irrigation techniques for many countries throughout the world was created. As an environmental impact, effects on water bodies, quality of agricultural soil, microbial communities of soil, and growth of plants have been summarized. For the impact on public health, significant emphasis was given to the exposure to pathogens and heavy metals for both farmers and consumers. The potential risks of utilizing sewage water for human consumption have also been summarised. Focusing on summarizing economic impact involves financial investment and benefits to sewage treatment plants and farmers.

The paper reviews the widely used heavy metal pollution indices (HPIs) in water, soil, and sediments and presents their numerical equation and application in various fields. HPIs are an essential and efficient tool to measure metal contamination in the environmental system. The present study includes twenty pollution indices from water, soil, and sediments for their comparative study with their ranges. In addition, the regional distribution of publications has been reviewed, and it observed that 68% were published from Asia, followed by other continents. The merits and demerits of each index have been presented, and a comprehensive method for selecting the appropriate pollution index is evaluated in order to better interpret the pollution level in soils and water systems. Among water quality indices HPI, HEI and HI have been used widely due to precise scale, easy to use, less limitations and provide efficient results. Among single indices, EF, I_geo, and CF are widely used and can be used in a simple manner for soil quality assessment, whereas in combined indices PLI and I_Nemerow are found to be useful as it is easy to apply and have precise scale. In integrated indices, C_d and I_Avg are found to be useful as it is easy to apply, and there is no limitation for heavy metals. Selection of appropriate geochemical background (GB) must be established, and the nature of fluctuation in GB may give a false result. The ecological risk index (ERI) is a unique index used to represent the ecological risk of metal pollution in water, soil, and sediment systems. A comprehensive approach and guidelines for using metal pollution indices in soil and sediment considering different sectors may be developed for each nation. The widespread application of HPI makes the study more accessible, and a well-defined result can be presented.

This research aimed to decipher the potential utility of Pseudomonas fluorescens strain c50 and Sphingobium yanoikuyae strain HAU in biodegradation and the mechanism of biochemical events occurring during the metabolic route of the herbicide atrazine. The bacterial strains c50 and HAU were isolated and identified based on 16S rRNA gene sequence analysis as P. fluorescens (accession no. OM838401) and S. yanoikuyae (accession no. OM830303), respectively. Both strains could survive in a concentration as high as 200 µg/mL of AT. Desethyl atrazine (DEA), desisopropyl atrazine (DIA), and desethylhydroxy atrazine (DEHA) were three critical metabolites produced during catabolism and quantified using GC–MS/MS. In culture medium, both strains effectively removed AT and its metabolites within 30 d with half-lives ranging from 2 to 9.9 d. Strain c50 performed better than HAU in rapid removal of AT and metabolites. In natural soil without microbial treatment, AT, DEA, DIA and DEHA persisted for 120, 90, 60 and 90 d, respectively with half-lives ranging from 12.1 to 26 d. Application of c50 and HAU accelerated degradation in soil. Persistence time of AT, DEA, DIA and DEHA was reduced to 25–30 d with half-lives ranging from 2.8 to 5.1 d. Strain HAU performed marginal better during biodegradation in soil. Performance of both the strains together was found at par. First-order dissipation kinetics was observed during biodegradation. Increase in microbial biomass carbon from 230 to 670 mg/kg soil indicated about initial surge (150 times) in bacterial population in treated soil and rapid biodegradation of contaminants using later as a food source. This study further revealed that identification of almost all major metabolites and intermediate products is possible using GC–MS/MS. However, reliable quantification of only DEA, DIA, and DEHA is possible without derivatization. Both bacteria could provide eco-friendly alternatives for attenuation of these toxicants from the contaminated soils.