Dumpsite Soil Research Articles

Akumulacija teških metala u kukuruzu (Zea Mais L.) gajenomna zemljištu izmenjenom dodavanjem komposta od čvrstog gradskog otpada

An experiment was conducted to investigate the accumulation of some heavy metals by maize (Zea mays L.) grown on soils amended with different levels of municipal solid waste compost (MSWC) in Dakadda experimental farm, Uyo. Eighteen plants samples were collected from three different plots and analyzed for heavy metals (Cd, Fe, Mn, Cu, and Pb) contents using atomic absorption spectrophotometry. Results obtained revealed the following ranges for the metals in grain: Cd:0.041-0.059mgkg-1 , Fe:42.62-62.23mgkg-1 , Mn:7.92-12.20mgkg-1 ; Cu:6.26-19.40mgkg-1 and Pb:0.25-0.36mgkg-1 , while the ranges in stover: Cd:0.029-0.120mgkg-1 , Fe:41.62-54.30mgkg-1 , Mn:14.21-20.43mgkg-1 ; Cu:10.46-24.30mgkg-1 and Pb:0.21-0.31mgkg-1. The results obtained from this study have shown considerable and unacceptable levels of heavy metals in maize grain and stover for the amended soils. It was observed that compost application increased the status or level of micro-nutrients when compared with the control plots (treatments), except for Mn and Cd in grain and Mn and Pb in the stover. On a general note, the concentrations of micronutrients were found to be higher in grain than in stover, except for Cu and Mn. The study also reveals that concentrations of most of the heavy metals analysed for in maize grains varied positively with their corresponding levels in stover. However, worthy of note is that although the levels of heavy metal contents obtained were within the permissible WHO and FAO standards, except for Lead, Pb, which was slightly higher than normal. It is believed that the results could be more favourable in this study than elsewhere because of the low content of industrial or hazardous wastes. Also, the waste could have been more degraded than might result from use of less than two years old dumpsite wastes elsewhere where there could be less highly degradable matter, less exposure to air before application to soil, drier waste, or where decomposition has been otherwise inhibited. Thus, on a general note, cultivating edible plants on dumpsite soils or soils reclaimed from a municipal solid waste disposal site, may not be safely used as a soil conditioner due to the fact that they have the potential of posing risk to crops or public health.

Organic Wastes Augment the Eco-Restoration Potential of Bamboo Species on Fly Ash-Degraded Land: A Field Study

Rapid industrialization has been a major cause of land degradation and other environmental problems globally. Most energy inputs in industries depend on coal-burning power stations which release various pollutants into the environment. Among these pollutants, fly ash is a concerning pollutant for soil quality, as it occupies a voluminous area of land in India and renders it unproductive. Therefore, this work attempts to evaluate the organic amendment-facilitated bioremediation/phytoremediation of fly ash-degraded land through bamboo plantations under field conditions. Three species of bamboo, Bambusa balcooa, B. tulda, and B. bambos, were planted on fly ash dumpsite soil amended with a combined dose of pressmud and farmyard manure. Results demonstrate that after two years of plantation, all the physicochemical attributes of the degraded land were improved considerably compared to the initial observations. Although all the bamboo species exhibited promising phytoremediation potential, variations were observed in their phytoremediation mechanisms: B. balcooa was the most ideal phytostabilizer species for Cu, Zn, and Ni. B. bambos was found as an ideal phytostabilizer of Pb and Zn while B. tulda was found as a phytoextractor of Cr and Zn. Additionally, all the bamboo species sequestrated atmospheric CO2 considerably, resulting in overall environmental restoration of the degraded area; B. balcooa was the most ideal species. Moreover, B. balcooa exhibited the highest air pollution tolerance index compared to other species. This study, therefore, recommends that a comprehensive analysis of organic matter-mediated phytoremediation would assist environmental managers to formulate sustainable eco-restoration strategies, ensuring a sustainable solution to land degradation.

ISOLATION AND CHARACTERIZATION OF CELLULOSE DEGRADING MICROORGANISMS GENERATING ELECTRICITY USING MICROBIAL FUEL CELL

Global warming and the accumulation of organic waste constitute a serious environmental problem. Therefore, microbial fuel cells (MFC) are an eco-friendly device that have significant capability for the production of electricity using biodegradable waste as fuel. Microorganisms used as catalysts in the anode compartment, execute a principal function in operating MFCs. The present study was conducted to isolate and to screen potential bioelectricity generating microorganisms from dumpsite soil samples and also to construct a domestic dual-chambered microbial fuel cell (MFC). Streptomyces fimicarius was found to be the best isolate for the degradation of cellulose and the production of bioelectricity. The bacterial isolate was identified based on morphological characteristics, biochemical characteristics and molecular identification using 16S rRNA. Double-chambered MFC was constructed by using two polypropylene plastic containers of 1.4 L volume each. The two chambers were joined by using an agar salt bridge and carbon rods were utilized as electrodes. The generation of electricity by the isolate was compared using glucose and cellulose as sole carbon source in a minimal medium. The maximum voltage was found to be 322 mV in the presence of cellulose used as substrate after 5 days of incubation at room temperature and last for 10 days.

Heavy Metals Concentration in Some Selected Dumpsites and Groundwater in Calabar, Cross River State, Nigeria

Heavy metals concentration in soil from dumpsites and borehole water in Calabar, Nigeria was analysed. Four dumpsites: Lemna (008°21'55.912"E and 05°2'08.725"N), Nassarawa (008°21'35.168"E and 05°4'51.544"N), University of Calabar female hostel (008°20'57.937"E and 04°56'16.612"N) and Goldie market (008°20'29.34"E and 04°56'29.198"N) were selected as sampling locations while a plot of land (008°21'43.9"E and 040'58.04 227"N) was selected as a control which were labeled S1, S2, S3, S4 and PC respectively. Soil and water samples were collected for a period of twelve months following a standard procedure and analysed for heavy metals using atomic absorption spectrophotometer (AAS) while physicochemical properties of water were analysed using their respective meters. The results obtained showed that in dumpsites soil: Cadmium was the highest occurring metal with a mean concentration of 1.457±0.493 mg/kg in S4 while As in S1 was the lowest occurring metal with a concentration of 0.001 ± 0.000 mg/kg and Hg was below detection limit in all sampling locations. In water: Chromium was the highest occurring metal with a concentration of 0.006 ± 0.001 mg/l and the lowest was Cobalt and Lead with concentrations of 0.001 ± 0.000 in about all the sampling locations while Arsenic and Mercury were below detection limit in all the sampling locations. Cd, Pb and Cr in S4 soil, Cd and Cr in S4 water and TDS, electrical conductivity and hardness of water from all dumpsites were above the WHO limit while strong positive correlation was found between some heavy metals concentration in soil and water.

Bacterial Communities in Informal Dump Sites: A Rich Source of Unique Diversity and Functional Potential for Bioremediation Applications

In this study, high-throughput metagenomic amplicon sequencing and physicochemical analyses were used to evaluate the structural composition and functional diversity of the soil bacterial communities at different illegal waste dump sites. Results showed that while the litter-free soil was dominated by the phylum Proteobacteria, dumpsite soils were enriched with phylum Actinobacteria, followed by Proteobacteria, Firmicutes, Chloroflexi, Acidobacteria, Planctomycetes, Bacteroidetes, and Gemmatimonadetes. Bacterial diversity differed significantly (p > 0.05) between the litter-free and contaminated sites, with each dumpsite having distinct genera that demonstrate the impact of waste type on the bacterial community composition. Genus Nocardioides, a versatile organic and inorganic pollutant-degrading bacteria in the class Actinomycetia, was dominant in the dump site soils, raising the possibility that this genus could serve as a potential biomarker for dump site soil pollution. PICRUSt functional profiling also showed the presence of genes involved in putative degradative pathways in the dump site soils. Furthermore, community-level physiological profile (CLPP) analyses revealed that the dump site soils are habitats to active bacterial communities with significant catabolic and carbon utilization capacity. Overall, this study provides a theoretical insight into the diversity and unique soil bacterial assemblages in illegal dump sites that could encode biotechnologically significant genes for biosynthesis and biodegradation.

Analysis of the Uptake and Distribution of Heavy Metals in Sweet Corn Grown on Municipal Solid Waste Dumpsite Soil in Delta State, Nigeria

Analysis of the Uptake and Distribution of Heavy Metals in Sweet Corn Grown on Municipal Solid Waste Dumpsite Soil in Delta State, Nigeria

Isolation and identification of promising antibiotic-producing bacteria

Abstract Multiple stresses in waste dumpsite soils can drive antibiotic production as one of the strategies for survival. Bacteria are the most prolific producers of antibiotics. This study investigated the antibiotic production potential of bacteria isolated from Bahir Dar city municipal solid waste dumpsite (MSWDS). Bacteria were isolated from soil collected from the dumpsite on starch casein or nutrient agar. The isolates were carefully screened for antimicrobial activity against six pathogenic bacterial test strains. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were also determined from cell-free metabolites of the most promising isolates. Isolates showing antimicrobial activity were identified using cultural and biochemical methods. A total of 143 distinctive colonies were obtained and tentatively identified to 13 bacterial genera. Twenty-six (18.18%) of the isolates (six Bacillus and 20 actinobacteria related) demonstrated antimicrobial activities at least against one of the tested bacterial strains. These isolates were related to two actinobacterial and 11 other bacterial genera. Seven out of 26 isolates showed a broad-spectrum of antibiotic activities. Two isolates, which showed a wide spectrum, were selected for the MIC and MBC tests against Escherichia coli and Staphylococcus aureus. The MIC and MBC of the isolates were recorded to be 250–500 µg/mL against the test strains. Bahir Dar city MSWDS contained a high incidence of antibiotic-producing bacteria. Strain level identification of the isolates and detailed characterization of the metabolites will give a good insight into the antimicrobial production potential in the waste dumpsite.

Health risk of some metals in maize grains cultivated close to Gosa and Gwagwalada solid waste dumpsites

Maize is a vital nutritional cereal for the infants, young children and adults. The environment which they are cultivated in Africa could expose to metal accumulations from soils, thereby posing health risks to the consumers. The objectives of this study were determine metal accumulations in maize grains (Zea mays L.) cultivated close to Gosa and Gwagwalada solid waste dumpsites and their health risks via consumption. A total of 36 soil samples (12 each from dumpsite soil, farmland soil and maize grains) were collected and analyzed for some metals [cadmium (Cd), lead (Pb), zinc (Zn), cobalt (Co), copper (Cu), chromium (Cr), nickel (Ni) and mercury (Hg)] using standard atomic adsorption spectrophotometer. The transfer factors and metal health risks in adults (60 kg; 22-48.9 years), young children (35 kg; 6-15 years) and infants (15 kg; 1-6 years) were evaluated using mathematical models. The ranges of metal (mg/kg) detected were 10114.00 to 0.52, 10.45 to 0.001 and 13.62 to 0.001 for dumpsite, farmland and maize grains, respectively. Though, within FAO/WHO and EU safe limits, Zn was significantly (p<0.05) highest in both locations, while Cd, Cr and Hg (0.001 mg/kg) were the least. Only Zn had transfer factor value below 0.5, which indicates possibilities of anthropogenic elevations. The estimated daily intake from consumption of maize grains (57 g) were generally high for Zn and low for Ni, Cd, and Hg in exposed individuals. The hazard index was below 1, which indicates no significant non-carcinogenic risks in exposed populations. The incremental lifetime cancer risks was below 10-6 and this suggest potential lifetime cancer risks in the order infants ? children ? adults. This study concluded that daily consumption of maize cultivated closed to dumpsites poses potential lifetime cancer concern and thus maize farming around dumpsites needs to be discouraged for safety reasons.

Enhanced Isolation of Streptomyces from Different Soil Habitats in Calamba City, Laguna, Philippines using a Modified Integrated Approach.

Streptomyces species are considered to be the most prolific sources of various bioactive secondary metabolites that are important for antibiotic production. Here, we describe a modified integrated approach to isolate Streptomyces species from diverse soil habitats, such as dumpsite, garden, forest, grassland, and riverside in Calamba City, Laguna, Philippines. A total of 25 soil samples were collected from a depth of 0-20 cm using systematic random soil sampling. All soil samples were air-dried, crushed, pretreated with calcium carbonate, and incubated on a rotary shaker. Isolation of Streptomyces in soil samples was then performed using the standard serial dilution plate technique on starch casein agar supplemented with nystatin (50 μg/ml) and ampicillin (5 μg/ml). Identification of the Streptomyces isolates was done using a polyphasic method that includes morphological and biochemical characterization. A total of 103 morphologically and biochemically distinct Streptomyces were isolated from diverse soil habitats. The number of Streptomyces isolates varied in each collection site, with the highest number collected from dumpsite soil and the least from forest soil. Most of the hydrogen sulfide producers were noted to be isolated from dumpsite samples. Moreover, more Streptomyces were isolated in soil habitats at higher altitudes with a slightly acidic to alkaline pH and a temperature ranging from 29 to 33°C. Employing the modified integrated approach, we have isolated up to 10 times more Streptomyces compared to early studies. These Streptomyces isolates can be valuable for future drug discovery and development research.

Heavy Metals Concentration In Soils And Bioaccumulation In Earthworm (Lumbricus Terrestris) At Lemna Solid Wastes Dumpsite, Calabar, Cross River State

This study investigated the concentrations of heavy metals and their bioaccumulation in earthworm in Lemna solid wastes dumpsite in Calabar, Cross River State, Nigeria. Three composite samples of the depth of 30 cm each were collected from Lemna dumpsites and control from the University of Calabar Botanical garden, making a total of four composite soil samples, while samples of earthworms were collected at each sampling point. The samples were analysed for Pb, Cd, Zn and Cu. The result showed that the levels of heavy metals were all higher in dumpsite and significantly different from the control. The respective means of metal concentrations from both Lemna and control were Pb(323.99mg/kg , 89.88mg/kg), Cd(1.12 mg/kg, 0.072 mg/kg), Zn(281 mg/kg, 7.60 mg/kg) and Cu(21.58 mg/kg, 4.89 mg/kg). Pb, Cd, Zn and Cu were also higher in earthworm of dumpsite than earthworm of the control soil. Correlation between Cadmium and Zinc concentration in soil and Cadmium and Zinc concentration in earthworm displayed strong and positive relationship while weak and negative correlation was observed between Cu and Pb concentrations in soil and Cu and Pb concentrations in earthworm. Bioaccumulation of the heavy metals by earthworm was in the order of Zn (0.382) > Cd (0.170) > Pb (0.076) > Cu (0.020). The dumpsite soil was found to be contaminated with Cd, Pb and Zn as their concentrations were high above maximum permissible limits except Cu. For safe consumption of crops from Lemna dumpsite soil, remediation of heavy metals in the soil in advocated.

Biomonitoring and Assessment of Dumpsites Soil Using Phospholipid Fatty Acid Analysis (PLFA) Method—Evaluation of Possibilities and Limitations

Dumped waste is not only a problem from an aesthetic point of view, but also has an environmental polluting effect, or can even pose a direct danger if the waste is dumped in illegal landfills in an uncontrolled manner with unknown composition. In the case of soil pollution, the assessment of the changing microbial state can be used as an indicator of initial changes, since waste as a pollutant impacts the diversity of the landfill’s microbial community. The degree of change depends on the qualitative and quantitative composition of the pollutants, which can be measured through the microbial phospholipid fatty acid (PLFA) pattern. The aim was a comprehensive assessment of the soil microbiological and toxicological hazards of various illegal landfill. Cluster-analysis of the average principal component revealed significant differences between the experimental sites. In comparison with the control site, the percentage of fatty acid biomarkers of Gram-positive bacteria was significantly higher in the contaminated areas, as well as the ratio of trans/cis isomerization in the case of 16:1ω7 and 18:1ω7 fatty acids. The inverse tendency was observed in the relative quantities of fatty acid biomarkers of Gram-negative bacteria compared to Actinomycetes, and in the fungal-bacterial ratio.

Effect of Nitrogen on the Phytoremediation of Cd-PAHs Co-contaminated Dumpsite Soil by Alfalfa (Medicago sativa L.) and on the Soil Bacterial Community Structure

The key point in facing the demand for the disposal of waste storage in rural areas of China is to manage informal landfills. However, limited studies have been conducted to evaluate the phytoremediation efficiency of heavy metal and polycyclic aromatic hydrocarbon (PAHs) co-contaminated dumpsite soil with high ammonia nitrogen content. In this study, we selected the tolerant plant legume alfalfa (Medicago sativa L.) for a pot experiment to investigate the effects of nitrogen (N) (0, 10, and 50 mg·kg-1) on plant growth, the removal of pollutants, and soil bacterial community structure in Cd-PAHs co-contaminated soil, so as to evaluate the role of N in the process of phytoremediation of dumpsite soil. The results showed that the biomass of alfalfa under high co-contamination conditions (Cd:10 mg·kg-1 and PAHs:400 mg·kg-1) increased with N supply and was 6.0 and 6.3 times higher than that of the treatment without N supply, respectively. Furthermore, the lower N level promoted the growth of alfalfa in the low-contamination group (Cd:1 mg·kg-1 and PAHs:100 mg·kg-1), but the difference was not significant, and a high concentration of N significantly inhibited its growth. In addition, the phytoremediation efficiency for Cd in the low-contamination group ranged from 5.58% to 7.49%, and N significantly increased the efficiency in the high co-contamination group from 0.95% to 3.02%. Compared with the removal of phenanthrene, N had a stronger influence on the removal of pyrene. Meanwhile, alfalfa could promote the removal of them in soil, among which the degradation of PAHs by microorganisms was dominant, whereas the contribution of the plant uptake pathway was less than 0.21%. As reflected by distance-based redundancy analysis (db-RDA), PAHs and Cd were the main factors affecting the structure of the microbial community; moreover, N had a greater effect on bacterial community composition in the single Cd-contamination and high co-contamination groups, promoting genera with bioremediation effects as the dominant soil bacterial communities, including Arthrobacter, Microbacterium, and Novosphingobium. This study will provide a theoretical basis for the remediation of dumpsites as well as informal landfills with contaminated soil.

Comparative Analysis of Heavy Metals Concentration in Soil and Vegetable (Celosia argentea) Collected from Two Sampling Sites and Their Effect on the Plant’s DNA Stability

This study investigated the quantities of heavy metals including cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb) and zinc (Zn)in soil samples and in the organs (leaf, stem and root) of Celosia argentea collected from a dumpsite (at Ojota) and a farmland (at Badagry) in Lagos, Nigeria. Additionally, the macroelement content of the soils and the effect of heavy metal soil contamination on C. argentea DNA stability was analysed. Heavy metals and NPK concentrations in the soil samples and organs of C. argentea were evaluated using standard techniques. The results of this study revealed that the microelement were more abundant in the soil collected from the dumpsite. Likewise, all the heavy metals (Cd,Cr,Cu,Pb and Zn) investigated in this study were detected in higher quantities in the dumpsite soil. Notably, the concentration of the metals was within the WHO/FAO limits in the soils collected from both sampling sites save Zn which was 660.260 mg/kg and 449.180mg/kg in the dumpsite and farmland respectively. The concentration of heavy metals in the C. argentea organs in this research were higher in samples collected from the dumpsite and Zn was the most accumulated on both the dumpsite and farmland. The highest amount (95.987 mg/kg) of Zn was by C. argentea root collected from the dumpsite while the least amount (15.380 mg/kg) was detected in C. argentea stem collected from the farmland. The DNA base pairs were not visibly fragmented in the samples C. argentea collected from the control and dumpsite sites. Although most of the heavy metals detected in C. argentea were in negligible quantities, the soils and the vegetable appear to be Zn-contaminated and unsafe for consumption. Keywords: Heavy Metal, DNA, vegetables, biomagnifications, Bioaccumulation, Dumpsites Farmlands

Assessment of Selected Heavy Metal Content on Dumpsites Soil and Vegetables Grown in Muwo Metropolis, Niger State, Nigeria

This study examines the concentration of heavy metals in soil samples and some vegetables (spinach, water leaf, bitter leaf and jute mallow) cultivated around dumpsites in Muwo Metropolis, Niger State, Nigeria. The soil samples and vegetable were analyzed for Ni, Zn, Cu, Pb and Cd using AA500 spectrophotometer after acid digestion. Data obtained show that, the Pb (1.684 mg/kg of Jute) content was high compared to other metals study in this work. Concentration of Zn was 1.993, 0.862 and 0.443 mg/kg for water leaf, soil and control sample respectively. The content of Pb was 1.727, 1.738 and ND mg/kg for water leaf, soil and control sample respectively. Also, the concentration of Pb was 1.736, ND and 0.457 mg/kg for spinach, soil and control sample respectively. However, the content of Zn was 0.786, 0.751 and 0.554 mg/kg for spinach, soil and control sample respectively The accumulation of heavy metals in agricultural soils is of increasing concern because of, potential health risks, food safety as well as its detrimental effects on the soil ecosystem and human health. The pollution indexes of Ni contents are 0.439, 0.378, and 0.083 for jute, soil and control sample respectively. While Zn concentration was 1.117, 0.858 and 0.492 for jute, soil and control sample respectively. The result of this study shows that Pb concentrations are present in high levels in the study area at the different level of contamination.

Comparative Analysis of Heavy Metals Concentration in Soil and Vegetable (Capsicum annum) Collected from Two Sampling Sites (Farmland and Dumpsite) and the Effect on Plant DNA

The levels of heavy metals and their effect on the DNA of Capsicum annuum collected from dumpsite (in Ojota) and farmland (in Badagry) in Lagos, Nigeria, were examined using standard procedures.
 The results of concentration of heavy metals in the soil for the farmland and dumpsite respectively are: Zn (882.0 ±0.006mg/kg, 14316.8±1.009mg/kg), Cr (2.006 ±0.002mg/kg,3.888± 0.002mg/kg), Cd (0.098 ± 0.001mg/kg, 0.644 ± 0.002mg/kg), Cu (0.206± 0.001mg/kg, 0.997 ± 0.001mg/kg) and Pb (0.005 ± 0.003mg/kg, 0.843± 0.002mg/kg) respectively. The values of N (3153.6± 0.008mg/kg, 4191.2± 0.006mg/kg), P (7598.3 ± 0.009mg/kg, 8794.5 ± 0.003mg/kg) and K (113.56 ± 0.004mg/kg, 532.12 ± 0.004mg/kg) were recorded in the soil from farmland and dumpsite respectively. While the values of N, P, and K in soil from dumpsite were higher (p<0.05) than that from farmland, the only value of Zn in the soil of dumpsite was significantly higher than in soil from farmland. Similarly, the values of all metals except Zn recorded in the leaf, stem, and root of C. annuum showed no significant difference between the sample collected from dumpsites and farmland. The values of Zn in leaf, stem, and root of C. annuum from farmland were significantly higher (p<0.05) than that of the dumpsite. The DNA bands of the Capsicum annuum from the control site have a clearer band spectrum than that from the dumpsite site, however, there was no DNA mutation. In conclusion, C. annuum collected from both farmland (in Badagry) and dumpsite (in Ojota) contained minerals and heavy metals whose concentrations were still within standard permissible limits. Thus, C. annuum from both sites is safe for human consumption.

ASSESSMENT OF THE HEAVY METALS AND PHYSICOCHEMICAL PROPERTIES OF SOILS, IN DUMPSITES AND ADJACENT FARMLANDS IN KAFANCHAN TOWN, KADUNA, NIGERIA

Purpose: This study focuses on establishing the presence and concentration of heavy metals as well as investigating the physicochemical properties of dumpsite soils and adjacent farms in the vicinity of Aduwan, Katsit, Bayan-loco, Ungwa Bala and Faringida in Kafanchan town, Kaduna Nigeria, using Atomic Absorption Spectrophotometry.
 Methodology: Surface soil was randomly sampled at the depth of (0-15 cm) from the dumpsites and adjacent farms and analyzed for physicochemical parameters and contamination by lead (Pb), chromium (Cr), Nickel (Ni) and cadmium (Cd).The sample soils were generally sandy-loamy with pH ranging from 7.30 to 7.28. The cation exchange capacity (CEC) ranged between 5.61cmol/kg and 7.80cmol kg−1. The mean concentrations of heavy metals in Aduwan dumpsite are: Ni(240.15±20.55 mg/L), Cr(45.65±1.15 mg/L), Pb(100.10±2.30 mg/L); Bayan-loco dumpsite: Ni(168.1±15.75 mg/L), Cr(41.05±6.45 mg/L), Pb(81.20±18.90 mg/L); Ugwan-bala dumpsite: Ni(175.65±3.45 mg/L), Cr(34.45±5.95 mg/L), Pb(98.95±2.30 mg/L); Farin-gida dumpsite: Ni(166.45±31.15 mg/L), Cr(58.25±28.85 mg/L), Pb(85.15±67.43 mg/L); Katsit dumpsite: Ni(125.25±6.85 mg/L), Cr(32.45±5.15 mg/L), Pb(76.80±1.42 mg/L).Cadmium was not detected at all in all sampled plots.
 Findings: Analytical results showed that Lead (Pb) was the predominant ion in soils of the sampled areas.
 Unique contribution to theory, practice and policy: The study observes that dumpsites were serving as major reservoirs of heavy metals. WHO identify the discussed heavy metals to be highly toxic therefore a better waste management system need to be instituted to minimize their accumulation soils.

Molecular Characterization of Antibiotic Resistant Bacteria from Soil within Rivers State University, Nigeria

Antibiotic resistance has become a subject of global concern to health systems all over the world and the shedding of antibiotic resistant bacteria from humans and animals into the soil is a threat to public health. This research was carried out to molecularly characterize and assess antibiotic resistant bacteria from soil in Rivers State University. Bacteria from soil in four locations; waste dump site, fish farm, poultry farm and home soil were enumerated and identified using standard microbiological techniques such as serial dilution, plating and incubation, isolation, biochemical testing and molecular identification. Sensitivity testing on the bacterial isolates was done using Kirby-Bauer Disk diffusion method. These resistant isolates were also subjected to molecular testing to ascertain the presence of resistant genes. The results revealed mean total Heterotrophic Bacterial Counts (THBC) for 32 samples ranged from 1.05±0.72 x 107 to 3.63±2.58x 107 CFU/g in fish farm and waste dump samples respectively. Total Coliform Counts (TCC) ranged from 3.65±2.91 x105 to 6.92±4.41 x105 CFU/g in Fish farm and Waste dump samples while Total Staphylococcal count ranged from 3.80±1.71 x104 to 11.46±9.21 x104 CFU/g in Fish farm and Waste dump samples respectively. Total Pseudomonad Count (TPC) ranged from 0.09±0.09 x 103 to 2.47±1.67x 103 CFU/g in Home soil and Fish farm samples. There was a difference (p≤0.05) in total heterotrophic bacterial, Staphylococcal and Pseudomonad counts, but no difference (p≥0.05) in total coliform. Seventy-nine (79) bacterial isolates were identified in this study belonging to the following genera; Bacillus spp, Staphylococcus spp., Micrococcus spp, Pseudomonas spp, Serratia spp, Proteus spp, Klebsiella spp, Salmonella spp and Escherichia spp with Staphylococcus (58.83%) having the highest occurrence and Pseudomonas (11.11%) had the least occurrence from the samples. Antibiotic sensitivity revealed that most isolates were resistant to many antibiotics tested with the highest resistance observed for Cefuroxime, Ceftazidime and Cefixime (100%) for the gram negative organisms and also Cefuroxime, Ceftazidime and Cloxacillin for gram positive bacteria. However, all bacteria showed sensitivity to gentamicin. Multiple Antibiotic resistance (MAR) index for all bacteria were above 0.2. Resistant bacterial isolates were identified molecularly as S. aureus, S. sciuri, M. luteus, B. cereus, B. subtilis, P. aeruginosa, S. mercescens, P. vulgaris, E. coli and Salmonella typhimurium. Pseudomonas aeruginosa, Serratia mercescens, Proteus vulgaris and E. coli had CTX-M gene present in their genome while Staphylococcus aureus, Staphylococcus sciuri, Micrococcus luteus, Bacillus cereus and Bacillus subtilis had the mecA gene present in their genome. This study has highlighted the rise in antibiotic resistance in bacteria from soil, hence, there is need to checkmate indiscriminate use of antibiotics in agriculture.

Impact evaluation with potential ecological risk of dumping sites on soil in Baglung Municipality, Nepal

This study is focused on the analysis of the impact caused by the municipal solid waste (MSW) dumping sites in Baglung Municipality of Nepal. For assessment of pollution level, physicochemical parameters of the dumping site's soil and potential ecological risk (PER) index was determined. The nature of the studied dumping site's soil was weakly acidic with high EC and TDS value. The result evidenced the higher values of available nitrogen (N), phosphorus (P) and potassium (K) which signify disposed waste is with high organic content. The concentration of heavy metals in the soil of dumping sites is ranked as Zn>Cu>Pb>Ni>Cr>Cd for the older sites and Zn>Cu>Pb>Ni>Cd>Cr for newer sites. The correlation matrix visualizes that there are positive correlations between Cr-Cd, Pb-Cd, Cu-Zn and Zn-Cd. PCA analysis shows the strong associations of NPK and heavy metals which depict their common source of contamination. The estimated PER index of each and multiple heavy metals represent older dumping sites have a higher potential for causing risk to the environment than the newer ones. This reflects the prospect of environmental threats due to haphazard disposal of MSW. The major implication of this research outcome is the necessity of monitoring and management of possible source of toxic heavy metals in MSW which may contaminate the nearby source of waterbodies by the runoff and infiltration of leachate produced by the dumping site. Also, it is advised to ensure the intense segregation of the MSW prior to final disposal.

A Review on Biodegradation Study of Disposable Face Masks

Coronavirus disease 2019 (COVID-19) plays a vital role in the pollution of micro-plastic. Currently, the increase in the use of polypropylene-based face masks has been an issue in waste management. This scenario will someday cause big environmental problems if the wastes are improperly managed. Thus, this review is aimed at analyzing the waste contributed by face masks and studying the factors that help fasten the degradation of face masks. These findings were analyzed according to the degradation of the polypropylene-based face mask under a few headings. The results have been presented and fallen into respective categories, and it shows that polypropylene does undergo deterioration in the landfill burial under the dumping site soil. It has been confirmed that there was heavy colonization of microbial communities from the used face masks. Thus, it is recommended that more research need to be done further to test the microbial effects of polypropylene-based face masks.

Optimization of nutritional and physical parameters for enhancing the keratinase activity of Bacillus cereus isolated from soil of poultry dump site in Gurugram, Haryana

Poultry waste especially feathers consists of over 90% proteins, which are primarily keratins. The enzyme assisted microbial degradation of keratins is a beneficial alternative to convert waste into value added products. In the present work, optimization of nutritional and physical parameters was achieved for Bacillus cereus strains to enhance the production of keratinases responsible for degradation of keratins present in feather waste. The results showed 2.29-fold increase in keratinase activity after optimization leading to 98.6 % degradation of feathers in 48 h for B. cereus strain H16 and 2.03 fold for strain H3 (2) resulting in 80.46 % degradation of feathers in 60 h. The study concluded that B. cereus H16 could be employed as potent keratinolytic bacterial isolate for processes involving conversion of keratinous waste into feed supplement and nitrogenous fertilizer.