A critical review of household recycling barriers in the United Kingdom

The UK recycling rate fluctuates between 45% and 47% and has consistently failed to meet the 65% target set by the post-Brexit Resource and Waste Strategy. Understanding the issues surrounding the low recycling rate in metropolitan cities in the UK will help to overcome these recycling challenges. The review examines the current situation with regards to the recycling rate and tonnage of waste produced in the UK based on available secondary waste flow data and explores different barriers related to household recycling. Many areas giving rise to the recycling challenges have been identified, including waste policy constraints, lack of effective communication, public engagement, physical barriers, service constraints, human factors, and socio-economic barriers. The literature review reveals factors such as waste policy, communication, and physical factors were the most important aspects in influencing recycling rate or output. It is concluded that a multi-dimension intervention is required, which includes a thorough review of waste policy, a more stringent enforcement, an improved communication strategy, and a more integrated planning development policy to mitigate issues affecting the UK’s low recycling rate or output. This approach will propel the local authorities to launch or initiate effective recycling management and to put in place the required infrastructure to facilitate effective recycling activities

Visual Similarity Perception of Directed Acyclic Graphs: A Study on Influencing Factors

While visual comparison of directed acyclic graphs (DAGs) is commonly encountered in various disciplines (e.g., finance, biology), knowledge about humans' perception of graph similarity is currently quite limited. By graph similarity perception we mean how humans perceive commonalities and differences in graphs and herewith come to a similarity judgment. As a step toward filling this gap the study reported in this paper strives to identify factors which influence the similarity perception of DAGs. In particular, we conducted a card-sorting study employing a qualitative and quantitative analysis approach to identify 1) groups of DAGs that are perceived as similar by the participants and 2) the reasons behind their choice of groups. Our results suggest that similarity is mainly influenced by the number of levels, the number of nodes on a level, and the overall shape of the graph.Comment: Graph Drawing 2017 - arXiv Version; Keywords: Graphs, Perception, Similarity, Comparison, Visualizatio

Chemistry and the environment

A report on three symposia in the ‘Energy, Water and Environmental Science’ programme at the International Union of Pure and Applied Chemistry (IUPAC) 46th World Chemistry Congress (in Sao Paulo, Brazil, 9-14 July, 2017). The symposia presented the latest advances concerning the environmental impact of emerging technologies and the fate of pollutants in the environment

Microbial community dynamics and their relationships with organic and metal pollutants of sugarcane molasses-based distillery wastewater sludge

Distillery sludge is a major source of aquatic pollution, but little is known about their microbial community and their association with the organic and metal pollutants. Sugarcane molasses-based distillery is an important industry in India, although the waste is usually treated prior to disposal, the treatment is often inadequate. The adverse effects of the organic and metal pollutants in sugarcane molasses-based distillery sludge on the microbial biodiversity and abundance in the disposal site have not been elucidated. This study aims to address this gap of knowledge. Samples were collected from the discharge point, 1 and 2 km downstream (D1, D2, and D3, respectively) of a sugarcane distillery in Uttar Pradesh, India, and their physico-chemical properties characterised. Using QIIME, taxonomic assignment for the V3 and V4 hypervariable regions of 16S rRNA was performed. The phyla Proteobacteria (28-39%), Firmicutes (20-28%), Bacteriodetes (9-10%), Actinobacteria (5-10%), Tenericutes (1-9%) and Patescibacteria (2%) were the predominant bacteria in all three sites. Euryechaeota, were detected in sites D1 and D2 (1-2%) but absent in D3. Spirochaetes (5%), Sinergistetes (2%) and Cloacimonetes (1%) were only detected in samples from site D1. Shannon, Simpson, Chao1, and Observed-species indices indicated that site D1 (10.18, 0.0013, 36706.55 and 45653.84, respectively) has higher bacterial diversity and richness than D2 (6.66, 0.0001, 25987.71 and 49655.89, respectively) and D3 (8.31, 0.002, 30345.53 and 30654.88, respectively), suggesting the organic and metal pollutants provided the stressors to favour the survival of microbial community that can biodegrade and detoxify them in the distillery sludge. This study confirmed that the treatment of the distillery waste was not sufficiently effective and provided new metagenomic information on its impact on the surrounding microbial community. It also offered new insights into potential bioremediation candidates

Antibiotic-resistant genes and bacteria as evolving contaminants of emerging concerns (e-CEC): is it time to include evolution in risk assessment?

The pressing issue of the abundance of antibiotic resistance genes and resistant bacteria in the environment (ARGs and ARB, respectively) requires procedures for assessing the risk to health. The chemo-centric environmental risk assessment models identify hazard(s) in a dose–response manner, obtaining exposure, toxicity, risk, impact and policy. However, this risk assessment approach based on ARGs/ARB evaluation from a quantitative viewpoint shows high unpredictability because ARGs/ARB cannot be considered as standard hazardous molecules: ARB duplicate and ARGs evolve within a biological host. ARGs/ARB are currently listed as Contaminants of Emerging Concern (CEC). In light of such characteristics, we propose to define ARGs/ARB within a new category of evolving CEC (or e-CEC). ARGs/ARB, like any other evolving determinants (e.g., viruses, bacteria, genes), escape environmental controls. When they do so, just one molecule left remaining at a control point can form the origin of a new dangerous and selection-responsive population. As a consequence, perhaps it is time to acknowledge this trait and to include evolutionary concepts within modern risk assessment of e-CEC. In this perspective we analyze the evolutionary responses most likely to influence risk assessment, and we speculate on the means by which current methods could measure evolution. Further work is required to implement and exploit such experimental procedures in future risk assessment protocols

Integrating phytoremediation into treatment of pulp and paper industry wastewater: Field observations of native plants for the detoxification of metals and their potential as part of a multidisciplinary strategy

This work aimed to explore the use of native herbs for the removal of heavy metals from pulp and paper industry wastewater, with the view of applying them as part of a multidisciplinary approach for detoxification. Results showed that after in-situ phytoremediation by the native herbs, the heavy metal, and metalloid contents in the wastewater were reduced by almost 60%. Heavy metal analysis of the plant tissues revealed that Fe accumulation was highest in all the tested plants. In general, the bioconcentration factor (BCF) was higher than one (>1) for all the metals except for Cd, suggesting most of the metals were concentrated in the plant tissues. In particular, As was concentrated significantly in Momordica doica and Cannabis sativa with elevated BCF of 269.46 and 131.20, respectively. High translocation factor (>1) was observed in P. hysterophorus and Tribulus terrestris for Cr (5.63) and Cd (7.53), respectively. Results showed most of the native plants examined in this study had hyperaccumulating tendency. Transmission electron microscope analysis of plant root tissues showed abundant metal depositions in the root cell wall, cytoplasm, and vacuole as strong evidence of the in-situ phytoremediation capability of these plants. Antioxidants activities of the plants such as superoxide dismutase, catalase, hydrogen peroxidase, peroxidase, and ascorbate peroxidase production were also noted to be higher than the control. These results support the use of native plants as a novel green process that can be integrated into the multidisciplinary treatment of hazardous industrial wastewater in the polluted sites

Degradation and detoxification of leather tannery effluent by a newly developed bacterial consortium GS-TE1310 for environmental safety

The untreated/partially treated effluent discharged from leather tanning industries is heavily polluting our water and soil resources. Hence, the adequate treatment/detoxification of tannery effluent (TE) is required before its safe disposal into the environment. In the present study, an effective degradation of real TE was attained by a newly developed bacterial consortium GS-TE1310 within 120 h with 76.12, 85.32, 71.89, 48.59, 78.81, 69.53, 71.22, and 88.70 % reduction in pollution parameters such as COD, BOD, TDS, phosphate, sulphate, nitrate, Cr, and phenol, respectively. The HP-LC, FT-IR, and GC–MS study showed that most of the organic contaminants identified in the untreated TE were completely mineralized/degraded into new degradation products in the treated TE by the newly developed bacterial consortium GS-TE1310 at 7 pH, 0.5 % glucose and ammonium chloride, 120 rpm, and 20 mL inoculum volume. Further, the bacterially treated TE was used for the phytotoxicity evaluation using Phaseolus aureus L as a terrestrial model organism. Results revealed that the toxicity of bacterially treated TE was significantly reduced, allowing the 70 % germination of seeds, and thus, confirmed the detoxification of leather TE. Overall, the newly developed bacterial consortium GS-TE1310 demonstrated a remarkable potential to efficiently treat/detoxify leather TE for environmental safety

The bacterial urban resistome: recent advances

Cities that are densely populated are reservoirs of antibiotic resistant genes (ARGs). The overall presence of all resistance genes in a specific environment is defined as a resistome. Spatial proximity of surfaces and different hygienic conditions leads to the transfer of antibiotic resistant bacteria (ARB) within urban environments. Built environments, public transportation, green spaces, and citizens’ behaviors all support persistence and transfer of antimicrobial resistances (AMR). Various unique aspects of urban settings that promote spread and resilience of ARGs/ARB are discussed: (i) the role of hospitals and recreational parks as reservoirs; (ii) private and public transportation as carriers of ARGs/ARB; (iii) the role of built environments as a hub for horizontal gene transfer even though they support lower microbial biodiversity than outdoor environments; (iv) the need to employ ecological and evolutionary concepts, such as modeling the fate of a specific ARG/ARB, to gain enhanced health risk assessments. Our understanding and our ability to control the rise of AMR in an urban setting is linked to our knowledge of the network connecting urban reservoirs and the environment

Distillery wastewater detoxification and management through phytoremediation employing Ricinus communis L.

This study aimed to assess the phytoremediation potential of Ricinus communis L. for heavy metals remediation via rhizospheric bacterial activities for distillery wastewater detoxification and management. Results revealed that distillery wastewater contained high levels of metals and other physico-chemical pollution parameters that could cause environmental pollution and aquatic toxicity. The identified bacterium produced several plant growth-promoting compounds including siderophores, ligninolytic enzymes, and indole acetic acid that resulted in nutrient enhancement and improved mineralization of metals in the plants during stress conditions. The bioconcentration factor (BCF) of all the metals examined were > 1, which showed that these metals are accumulating in the root, shoot, and leaves of Ricinus communis L. Most of the metals are stabilised in the roots but Pb, Cd and Zn were translocated more to the shoots (TC>1). The ability of Ricinus communis L. to grow in metals- containing distillery wastewater and reduce heavy metals and organic contaminants suggests that it can be used to provide an effective treatment of distillery wastewater. The use of Ricinus communis L. is an eco-friendly tool for the reduction of organometallic contamination and protecting agricultural land