Phytoremediation of heavy metal contaminated soil using different plant species

A pot experiment was conducted to compare the plant biomass accumulation and heavy metal (HM) uptake by plant species grown in HM contaminated soils. The shoot dry weights of Eucalyptus camaldeulensis, Medicago sativum, and Brassica juncea grown in contaminated soils were reduced by 8, 5, and 3-fold, respectively, compared to the same plants grown in control soil. The Pb concentration in the shoots of M. sativum, E. camaldeulensis and B. juncea grown in contaminated soil was 8.7, 11.0, and 8.8-fold, respectively, higher than Pb concentration in plants grown in control soils. M. sativum and E. camaldeulensis accumulated higher Zn concentrations in roots (71 and 86 mg kg-1) and shoots (49 and 47 mg kg-1), respectively. Zn concentrations in the roots of M. sativum, E. camaldeulensis and B. juncea were higher than in the shoots by a factor of 1.4, 1.8, and 1.3-fold, respectively. The highest Cu concentration (81 and 37 mg kg-1 dwt) was obtained in root and shoot of M. sativum grown in contaminated soil, while the highest Cr concentration (133.9 mg/kg dwt) was determined in the root of E. camaldeulensis. This suggests that E. camaldeulensis was the best candidate species for phytoremediation of HM contaminated soils.Keywords: Phytoextraction, Roadside soil, Heavy metal, Brassica juncea, Medicago sativum, Eucalyptus camaldeulensi

A meta-analysis of metal biosorption by suspended bacteria from three phyla

Biosorption of heavy metals by bacterial biomass has been the subject of significant research interest in last decades due to its efficiency, relatively low cost and minimal negative effects for the surrounding environment. In this meta-analysis, the biosorption efficiencies of different bacterial strains for Cu(II), Cd(II), Zn(II), Cr(III), Mn(II), Pb(II) and Ni(II) were evaluated. Optimum conditions for the biosorption process such as initial metal concentration, temperature, pH, contact time, metal type, biomass dosage and bacterial phyla, were evaluated for each heavy metal. According to the results, the efficiencies of bacterial biomass for removal of heavy metal were as follows: Cd(II) > Cr(III) > Pb(II) > Zn(II) > Cu(II) > Ni(II) > Mn(II). Firmicute phyla showed the highest overall (living and dead) biosorption efficiency for heavy metals. Living biomass of Proteobacteria had the best biosorption performance. Living bacterial biomass was significantly more efficient in biosorption of Cu(II), Zn(II) and Pb(II) than dead biomass. The maximum biosorption efficiency of bacterial strains for Cd(II), Pb(II) and Zn(II) was achieved at pH values between 6 and 7.5. High temperatures (>35 °C) reduced the removal efficiencies for Cu(II) and Zn(II) and increased the efficiencies for Cd(II) and Cr(III) ions. The maximum biosorption efficiency of non-essential heavy metals occurred with short contact times (24 h). The mean biosorption capacity of bacterial biomass was between 71.26 and 125.88 mg g−1. No publication bias existed according to Egger’s and Begg’s test results

Mechanical and leaching characterisation of impact-absorbing rubberised asphalts for urban pavements

A new impact-absorbing material is being developed to protect vulnerable road users in urban areas and has been produced and tested, mechanically and environmentally in the laboratory. The main constituent of this innovative material is the rubber recycled from end-of-life tyres to foster a circular use of resources and exploit rubber’s elastic properties. The study aims to provide a complete Uniaxial Compression Test (UCT) and leaching analysis of the material to propose and optimise a mix that is mechanically sound, durable, and respectful of the environment, in view of in-situ applications. Therefore, the UCT and Dynamic Surface Leaching Test (DSLT) were carried out on rubberised asphalt specimens with different mix designs. The 64 days cumulative concentrations of leached heavy metals and trace elements from unit surface of specimens were calculated and quantified, according to the CEN/TS 16637 standard. In parallel, thanks to a specific mechanical characterisation, compressive stress–strain curves were obtained, and the relaxation and elastic modulus were evaluated. The results from the compression tests showed that the A-mixes have the best elastic and absorbing behaviour, especially those made with an SBS-modified bituminous emulsion (A4). The results from DSLT showed that the cumulative concentration of released elements, per unit surface of specimens were lower than the Dutch Soil Quality Decree (SQD) thresholds, taken as a reference. The low and early release of leachant observed for the mixtures, especially A4 as the most promising one, leave the possibility to handle the leaching with several solutions, including rubber coating treatment or water washing before their incorporation into the mix to limit and prevent their leaching while permitting very high injury reduction performances

Descriptive Analysis of the Performance of a Vegetated Swale through Long-Term Hydrological Monitoring: A Case Study from Coventry, UK

Vegetated swales are a popular sustainable drainage system (SuDS) used in a wide range of environments from urban areas and transport infrastructure, to rural environments, sub-urban and natural catchments. Despite the fact that vegetated swales, also known as grassed swales, have received scientific attention over recent years, especially from a hydrological perspective, there is a need for further research in the field, with long-term monitoring. In addition, vegetated swales introduce further difficulties, such as the biological growth occurring in their surface layer, as well as the biological evolution taking place in them. New developments, such as the implementation of thermal devices within the cross-section of green SuDS for energy saving purposes, require a better understanding of the long-term performance of the surface temperature of swales. This research aims to contribute to a better understanding of these knowledge gaps through a descriptive analysis of a vegetated swale in Ryton, Coventry, UK, under a Cfb Köppen climatic classification and a mixed rural and peri-urban scenario. Precipitation and temperature patterns associated with seasonality effects were identified. Furthermore, a level of biological evolution was described due to the lack of periodical and planned maintenance activities, reporting the presence of both plant species and pollinators. Only one event of flooding was identified during the three hydrological years monitored in this research study, showing a robust performance

The addition of a goal-based motivational interview to standardised treatment as usual to reduce dropouts in a service for patients with personality disorder: a feasibility study

<p>Abstract</p> <p>Background</p> <p>Rates of non-completion of treatments for personality disorder are high and there are indications that those who do not complete treatment have worse outcomes than those who do. Improving both cost-efficiency and client welfare require attention to engaging people with personality disorder in treatment. A motivational interview, based on the Personal Concerns Inventory, may have the ability to enhance engagement and retention in therapy. Here, we report the protocol for a feasibility study for a randomised controlled trial (RCT).</p> <p>Methods</p> <p>All referrals accepted to the psychological service of Nottinghamshire Healthcare NHS Trust's outpatient service for people with personality disorder are eligible for inclusion. Consenting participants are randomised to receive the Personal Concerns Inventory interview plus treatment as usual or treatment as usual only. We aim to recruit 100 participants over 11/2 years. A randomised controlled trial will be considered feasible if <abbrgrp><abbr bid="B1">1</abbr></abbrgrp> the recruitment rate to the project is 54% of all referrals (95% CI 54-64), <abbrgrp><abbr bid="B2">2</abbr></abbrgrp> 80% of clients find the intervention acceptable in terms of its practicability and usefulness (95% CI 80-91), and <abbrgrp><abbr bid="B3">3</abbr></abbrgrp> 80% of therapists report finding the intervention helpful (95% CI 80-100). In a full-scale randomised controlled trial, the primary outcome measure will be completion of treatment i.e., entry into and completion of ≥ 75% of sessions offered. Therefore, information will be collected on recruitment rates, attendance at therapy sessions, and completion of treatment. The feasibility of examining the processes of engagement will be tested by assessing the value, coherence, and attainability of goals pre-treatment, and engagement in treatment. The costs associated with the intervention will be calculated, and the feasibility of calculating the cost-benefits of the intervention will be tested. The views of clients and therapists on the intervention, collected using semi-structured interviews, will be analysed using thematic analysis.</p> <p>Discussion</p> <p>The Personal Concerns Interview as a preparation for treatment of people with personality has the potential to maximise treatment uptake, reduce unfilled places in treatment programmes, and prevent group treatments faltering through non-attendance. Most importantly, it has the potential to improve patient outcomes, helping them to function better and reduce hospitalisation.</p> <p>Trial Registration</p> <p>ClinicalTrials.Gov.UK Identifier - NCT01132976</p

Rehabilitation versus surgical reconstruction for non-acute anterior cruciate ligament injury (ACL SNNAP): a pragmatic randomised controlled trial

BackgroundAnterior cruciate ligament (ACL) rupture is a common debilitating injury that can cause instability of the knee. We aimed to investigate the best management strategy between reconstructive surgery and non-surgical treatment for patients with a non-acute ACL injury and persistent symptoms of instability.MethodsWe did a pragmatic, multicentre, superiority, randomised controlled trial in 29 secondary care National Health Service orthopaedic units in the UK. Patients with symptomatic knee problems (instability) consistent with an ACL injury were eligible. We excluded patients with meniscal pathology with characteristics that indicate immediate surgery. Patients were randomly assigned (1:1) by computer to either surgery (reconstruction) or rehabilitation (physiotherapy but with subsequent reconstruction permitted if instability persisted after treatment), stratified by site and baseline Knee Injury and Osteoarthritis Outcome Score—4 domain version (KOOS4). This management design represented normal practice. The primary outcome was KOOS4 at 18 months after randomisation. The principal analyses were intention-to-treat based, with KOOS4 results analysed using linear regression. This trial is registered with ISRCTN, ISRCTN10110685, and ClinicalTrials.gov, NCT02980367.FindingsBetween Feb 1, 2017, and April 12, 2020, we recruited 316 patients. 156 (49%) participants were randomly assigned to the surgical reconstruction group and 160 (51%) to the rehabilitation group. Mean KOOS4 at 18 months was 73·0 (SD 18·3) in the surgical group and 64·6 (21·6) in the rehabilitation group. The adjusted mean difference was 7·9 (95% CI 2·5–13·2; p=0·0053) in favour of surgical management. 65 (41%) of 160 patients allocated to rehabilitation underwent subsequent surgery according to protocol within 18 months. 43 (28%) of 156 patients allocated to surgery did not receive their allocated treatment. We found no differences between groups in the proportion of intervention-related complications.InterpretationSurgical reconstruction as a management strategy for patients with non-acute ACL injury with persistent symptoms of instability was clinically superior and more cost-effective in comparison with rehabilitation management