Heavy metal screen tests

A heavy metal resistant bacterial strain, TWSL_22 was isolated from an industrial effluent sample and tested for heavy metal tolerance and resistance. The strain was molecularly characterized as Staphylococcus epidermidis based on 16S rRNA gene analysis and the sequence was deposited in the NCBI repository (Accession number KT184893.1). Metal removal activity (P < 0.001) of TWSL_22 was 99.99 ± 0.001%, 74.43 ± 2.51% and 51.16 ± 4.17% for Cd, Pb and Cu respectively...

In wells with high-viscosity crude oil, steam injection is used to improve the fluidity of the heavy oil. Screens made of steel are employed for sand control, with corrosion being a serious problem. Non-metallic pipe materials, such as novel high-strength PVC, are therefore being tried out. This paper presents the results of an integrity assessment of large-diameter hard PVC pipes under compressive loading. Plain, built-up, and slotted pipes were subjected to a 3-month aging process in saline water. Strain gauge sets were used for dynamic testing of longitudinal and transverse deformations...

Considering the high risk of heavy metal ions (HMIs) transferring through the food chain and accumulating in milk, a flexible and facile point-of-care testing (POCT) platform is urgently needed for the accurate, sensitive, and highly selective on-site quantification of multiple HMIs in milk. In this work, a cost-effective disk with six screen-printed electrodes (SPEs) was designed for hand-held electrochemical detection. Metal organic frameworks (MOFs) were adopted to amplify and enhance the electrochemical signals of methylene blue (MB)...

Background: The study was conducted in a Dallas lead smelter community following an Environmental Protection Agency (EPA) Superfund Cleanup project. Lead smelters operated in the Dallas community since the mid-1930s. Aim: To test the hypothesis that cadmium (Cd) exposure is associated with chronic kidney disease (CKD) ≥ stage 3. Subjects and methods: Subjects were African American residents aged ≥19 to ≤ 89 years (n=835). CKD ≥ stage 3 was predicted by blood Cd concentration with covariates...

In this work, a screen-printing method was developed to create porous particle-based materials as layers with specifically designed shape to produce microfluidics systems. Among several tested binding agents, xanthan gum was found to be an excellent choice for a printing mixture thickener as well as a durable binder for the resulting material. In addition to demonstrating control over the shape of the printed microfluidics chips, control over material thickness, wetting characteristics and general method accuracy were also investigated...

Industrial wastewater often consists of toxic chemicals and pollutants, which are extremely harmful to the environment. Heavy metals are toxic chemicals and considered one of the major hazards to the aquatic ecosystem. Analytical techniques, such as potentiometric methods, are some of the methods to detect heavy metals in wastewaters. In this work, the quantitative structure-property relationship (QSPR) was applied using a range of machine learning techniques to predict the stability constant (logβML ) and potentiometric sensitivity (PSML ) of 200 ligands in complexes with the heavy metal ions Cu2+ , Cd2+ , and Pb2+ ...

Microbially induced calcite precipitation (MICP) is an efficient and eco-friendly technique that has attracted significant interest for resolving various problems in the soil (erosion, improving structural integrity and water retention, etc.), remediation of heavy metals, production of self-healing concrete or restoration of different concrete structures. The success of most common MICP methods depends on microorganisms degrading urea which leads to the formation of CaCO3 crystals. While Sporosarcina pasteurii is a well-known microorganism for MICP, other soil abundant microorganisms, such as Staphylococcus bacteria have not been thoroughly studied for its efficiency in bioconsolidation though MICP is a very important proccess which can ensure soil quality and health...

A 2-year-old male African penguin ( Spheniscus demersus ) was presented to a veterinary teaching hospital for evaluation of a previously diagnosed subclinical, marked regenerative anemia. Physical examination at the zoological institution demonstrated biliverdinuria and pale oral mucous membranes. Diagnostic tests performed on the penguin since the diagnosis and prior to presentation to the veterinary teaching hospital included serial complete blood counts, plasma biochemistry panels, radiographic imaging, blood and plasma heavy metal testing, and infectious disease testing...

Today application of sewage sludge (SL) and hydrochar (HC) in agriculture is a common practice for soil conditioning and crop fertilization, however safety concerns for human and environmental health due to the presence of toxic compounds have recently been expressed. Our aim was to test the suitability of proteomics coupled with bioanalytical tools for unravelling mixture effects of these applications in human and environmental safety assessment. We conducted proteomic and bioinformatic analysis of cell cultures used in the DR-CALUX® bioassay to identify proteins differentially abundant after exposure to SL and the corresponding HC, rather than only using the Bioanalytical Toxicity Equivalents (BEQs) obtained by DR-CALUX®...

To effectively carry out the bioremediation of a Pb2+ polluted environment, a lead-tolerant strain named D1 was screened from the activated sludge of a factory in Hefei, and its lead removal in a solution with Pb2+ concentration of 200 mg/L could reach 91% under optimal culture conditions. Morphological observation and 16S rRNA gene sequencing were used to identify D1 accurately, and its cultural characteristics and lead removal mechanism were also preliminarily studied. The results showed that the D1 strain was preliminarily identified as the Sphingobacterium mizutaii strain...

The environmental risks associated with the storage, reuse, and disposal of unencapsulated reclaimed asphalt pavement (RAP) has been previously examined, but because of a lack of standardized column testing protocols and recent interest on emerging constituents with higher toxicity, questions surrounding leaching risks from RAP continue. To address these concerns, RAP from six, discrete stockpiles in Florida was collected and leach tested following the most up-to-date, standard column leaching protocol - United States Environmental Protection Agency (US EPA) Leaching Environmental Assessment Framework (LEAF) Method 1314...

Phytoremediation, as a green and effective in-situ remediation technology for heavy metal-contaminated soil, has attracted the attention of Chinese scholars and has resulted in a series of achievements over the past 20 years. In this study, the species characteristics, distribution of field discovery sites in various vegetation zones, habitat characteristics, habitat geological characteristics, and geochemistry of cadmium (Cd) of the Cd hyperaccumulators in China reported in the relevant literature from the past 20 years (from 2002 to 2021) were summarized by searching for related keywords...

Cellulose can be modified for the loading of functional groups such as amino groups, sulfydryl groups, and carboxyl groups. Cellulose-modified adsorbents generally have specific adsorption capacities for either heavy metal anions or cations, and possess the advantages of wide raw material source, high modification efficiency, high adsorbent recyclability, and great convenience in recovery of the adsorbed heavy metals. At present, preparation of amphoteric heavy metal adsorbents from lignocellulose has attracted great attention...

Microbial toxicity tests are considered efficient screening tools for the assessment of water contamination. The objective of this study was to develop a sulfur-oxidizing bacteria (SOB)-based ecotoxicity test with high sensitivity and reproducibility for simple and rapid on-site application. To attain this goal, we developed a 25 mL vial-based toxicity kit and improved our earlier SOB toxicity test technique. The current study applied a suspended form of SOB and shortened the processing time to 30 min. Moreover, we optimized the test conditions of the SOB toxicity kit in terms of initial cell density, incubating temperature, and mixing intensity during incubation...

Water quality criteria (WQC) are developed to protect aquatic organisms. Toxicity data of local fish are essential to improve the applicability of WQC derivatives. However, the paucity of local cold-water fish toxicity data limits the development of WQC in China. Brachymystax lenok is a representative Chinese-endemic cold-water fish, which plays an important role in the characterization of metal toxicity in the water environment. Whereas, the ecotoxicological effects of copper, zinc, lead and cadmium, as well as its potential as a test species for the metal WQC, remain to be investigated...

Soil pollution with heavy metals is a serious threat to the environment. However, soils polluted with heavy metals are considered good sources of native metal-resistant Trichoderma strains. Trichoderma spp. are free-living fungi commonly isolated from different ecosystems, establishing endophytic associations with plants. They have important ecological and biotechnological roles due to their production of a wide range of secondary metabolites, thus regulating plant growth and development or inducing resistance to plant pathogens...

AIMS: To screen heavy metal-tolerant strains from heavy metal-contaminated soil in mining areas and determine the tolerance of the strains to different heavy metals and their removal rates through experiments. METHODS: Mercury-resistant strain LBA119 was isolated from mercury-contaminated soil samples in Luanchuan County, Henan Province, China. The strain was identified by Gram staining, physiological and biochemical tests, and 16S rDNA sequences. The LBA119 strain showed good resistance and removal rates to heavy metals such as Pb2+ , Hg2+ , Mn2+ , Zn2+ , and Cd2+ using tolerance tests under optimal growth conditions...

The current study evaluated Parapedobacter indicus MCC 2546 for its potential to produce a bioemulsifier (BE). Screening methods performed for BE production by P. indicus MCC 2546 showed good lipase activity, positive drop collapse test, and oil-spreading activity. Furthermore, it showed maximum emulsification activity (225 EU/ml) and emulsification index (E24 50%) at 37°C in Luria Bertani broth at 72 h with olive oil as a substrate. The optimal pH and NaCl concentration for maximum emulsification activity were 7 and 1%, respectively...

A comprehensive and scientific assessment of benthic ecosystem health is key to the rational selection of endogenous pollution reduction technologies for lakes. However, current assessments are mainly limited to biological indicators and ignore the actual benthic ecosystem situations, such as the impact of eutrophication and heavy metal pollution, which may lead to the one-sidedness of the evaluation results. In this study, taking Baiyangdian Lake, the largest shallow mesotrophic-eutrophic lake in the North China Plain, as an example, the chemical assessment index and biological integrity index were first combined to estimate the biological conditions, nutritional status and heavy metal pollution of lakes...

Phytophthora infestans , the notorious pathogen of potato late blight, leads to a severe decline in potato yields and even harvest failure. We isolated 201 endophytic isolates from healthy root tissues of potatoes, among which 41 showed strong antagonistic activity against P. infestans . Further, the tolerance to stress and the potential application against potato late blight of these antagonistic isolates were tested. Most of them were extremely tolerant to stresses such as acid-alkali, temperature, UV, salt, and heavy metal stress...