Minimizing hazardous impact of food waste in a circular economy - Advances in resource recovery through green strategies.

Recent trends in food waste and its management have increasingly started to focus on treating it as a reusable resource. The hazardous impact of food waste such as the release of greenhouse gases, deterioration of water quality and contamination of land areas are a major threat posed by food waste. Under the circular economy principles, food waste can be used as a sustainable supply of high-value energy, fuel, and nutrients through green techniques such as anaerobic digestion, co-digestion, composting, enzymatic treatment, ultrasonic, hydrothermal carbonization. Recent advances made in anaerobic co-digestion are helping in tackling dual or even multiple waste streams at once with better product yields. Integrated approaches that employ pre-processing the food waste to remove obstacles such as volatile fractions, oils and other inhibitory components from the feedstock to enhance their bioconversion to reduce sugars. Research efforts are also progressing in optimizing the operational parameters such as temperature, pressure, pH and residence time to enhance further the output of products such as methane, hydrogen and other platform chemicals such as lactic acid, succinic acid and formic acid. This review brings together some of the recent progress made in the green strategies towards food waste valorization.

Bioprocessing of waste biomass for sustainable product development and minimizing environmental impact.

Growing concerns around the generation of biomass waste have triggered conversation around sustainable utilization of these seemingly waste materials as feedstock towards energy generation and production of chemicals and other value-added products. Thus, biotechniques such as utilization of microbes and enzymes derived thereof have become important avenues for green pretreatment and conversion of biomass wastes. Although the products of these bioconversions are greener at an overall level, their consumption and utilization still impact the environment. Hence it is important to understand the overall impact from cradle to grave through lifecycle assessment (LCA) techniques and find avenues of process optimization and better utilization of all the materials and products involved. Another factor to consider is overall cost optimization to make the process economically feasible, profitable and increase industrial adoption. This review brings forward these critical aspects to provide better understanding for the advancement of bioeconomy.

Single-use plastics: Production, usage, disposal, and adverse impacts.

Single-use plastics (SUPs), invented for the modern "throwaway society," are intended to be used only once. They are being increasingly produced and used globally, most notably as packaging or consumables, such as SUP shopping bags or disposable tableware. We discuss how most SUPs are landfilled or incinerated, which causes pollution, consumes valuable land, and squanders limited natural resources. Only relatively small amounts are currently recycled, a hindrance to the concept of a circular economy. Moreover, SUP litter aggregation in the natural environment is a major concern. This article briefly reviews SUP contamination in various environmental media including soil, rivers, lakes and oceans around the world. In the face of mounting evidence regarding the threat posed to plant growth, soil invertebrates and other land animals, (sea) birds, and marine ecosystems, there is a growing push to minimize SUPs. Regulatory tools and voluntary actions to reduce SUP usage have been put forward, with some suggestions for minimizing SUP waste.

Biotechnological Potential for Microplastic Waste.

Plastic has become a critical material in the modern world due to its low cost and easy production. However, inadequate management and open disposal make plastic a major obstacle to achieving the UN Sustainable Development Goals. This article emphasizes the role of biotechnology in addressing the issue of microplastic waste.

Sustainable Bioprospecting of Electronic Waste.

Global electronic waste management is emerging as a critical issue, especially in developing countries. Collective societal effort and scientific innovation are required along with interdisciplinary approaches to the development of sustainable technologies for recycling precious metals. Bioprospecting of electronic waste is a promising approach to provide economic, environmental, and public health benefits.

Mechano-microbial systems: An ecofriendly approach for copper bioleaching from waste printed circuit board.

Waste printed circuit board (PCB) is attracting serious concerns because the recycling of its valuable metallic portion is made difficult by the existence of hazardous substances. The objective of the present study was to develop a simplified approach for copper bioleaching from waste PCB. In this context, we intended mechano-microbial systems symbolized as SET-I (spore suspension + potato dextrose broth medium + waste PCB powder), SET-II (pre-cultured until the logarithmic phase, without waste PCB powder), and SET-III (fungal metabolites produced at stationary phase). The results of bioleaching studies showed that the developed method achieved the highest copper leaching of 85% by the SET-III approach. This study provides an insight for bioleaching copper from waste PCB. Furthermore, this approach can be established as an ecofriendly method for copper bioleaching by using an integrated system.

Environmental pollution and human body burden from improper recycling of e-waste in China: A short-review.

BRIEF BACKGROUND: E-waste generation has become a serious environmental challenge worldwide. The global quantity of e-waste was estimated 44.7 million metric tons (Mt) in 2016. The improper recycling of e-waste is still a challenging issue in developing countries. OBJECTIVE: The objectives of this a review article to present comprehensive information of recent studied on environment pollution and effect on human health in China. METHOD: The search engines consulted, period of publications reviewed 2015-2018. For search study, we used different key words: 'improper recycling', 'primitive recycling,' 'backyard recycling,' 'e-waste,' 'WEEE', and the studies related to improper recycling of e-waste. RESULTS: According to reports, the e-waste recycled by unorganized sectors in China. These unorganized sector workers daily go for work, such as e-waste collection from consumer house and manual dismantling of e-waste by using simple method, at unauthorized workshop. These backyard workshop are reported in small clusters in or around city e.g., Qingyuan village; Taizhou, Longtang Town, Guiyu, nearby Nanyang River and Beigang River in China. DISCUSSION: The earlier reported studies directed the heavy metals effect (causing effects both acute and chronic effects; respiratory irritation, reproductive problem, cardiovascular and urinary infection/disease) on human health. According the reports, the improper recycling of e-waste which need to be address for the environment protection and prevention of public health risk. However, if e-waste exposure is not avoided very well, the associated contamination will be continuing, and simultaneously needful to increase the awareness for proper e-waste management in China. CONCLUSIONS: In order to solve the e-waste problem in China, more detail research is needed. Furthermore, for environment protection and health safety, the proper e-waste dismantling techniques, environmentally sound management, and the regular monitoring are very important.

E-waste management in India: A mini-review.

Environmental deterioration and health risk due to improper e-waste management has become a serious issue in India. The major portion of e-waste reaches an unorganized e-waste recycling sector and is then treated by using crude methods. This review article presents a brief highlight on e-waste management status, legislation, and technology uses in India. The present e-waste management needs to be more focused on environmentally sound management, by more active support from all the participants involved in the e-waste flow chain in India.

Assessing resident awareness on e-waste management in Bangalore, India: a preliminary case study.

The generation of e-waste has increased significantly in India, and the informal recycling of e-waste has adverse effects on environment and public health. In this article, the E-waste management is evaluated in accordance from the resident's awareness perspective in Bangalore city, India. The survey data revealed that about 58% male and 42% female responded and 35% of the participants belong to age range between 18 and 25 years. About 60% of respondent's education level was either graduate or post graduate, 27% high school to higher school, 10% higher educated (> post graduate), and 3% primary to middle. Only 30% of the respondents were confident with e-waste rules and regulation, while 39% of the respondents were of very little information. Indian e-waste management has been improving for the last few years and it continues to develop. Therefore, the findings can be valuable for better understanding the resident's awareness for e-waste management and also need to promote the environmentally sound management of e-waste in Bangalore, India.

Modelling the correlations of e-waste quantity with economic increase.

Waste from Electrical and Electronic Equipment (WEEE or e-waste) is regarded as one of the fastest growing waste streams in the world and is becoming an emerging issue owing to adverse consequences on the natural environment and the human health. This research article reveals the presence of a strong linear correlation among global e-waste generation and Gross Domestic Product. The obtained results indicate that the best fit for data can be reached by comparing e-waste collected volumes and GDP PPS. More in detail, an increase of 1000 GDP PPS means an additional 0.27kg of e-waste collected and 0.22kg of e-waste reused/recycled. Furthermore, for each additional citizen, there will be an increase of 7.7kg of e-waste collected and 6.2kg of e-waste reused/recycled. The better collection of e-waste acts an important role concerning the circular economy, and it can be an advantageous approach. Therefore, e-waste could be considered as an opportunity for recycling or recovery of valuable metals (e.g., copper, gold, silver, and palladium), given their significant content in precious metals than in mineral ores.

The dynamic of cellulase activity of fungi inhabiting organic municipal solid waste.

The study dealt with to identified and screened out potential cellulase producing fungal strains. All the indigenous fungal strains were developed on carboxymethyl cellulose (CMC) mandel media at 30 °C for 3-4 days to examine their congo red cellulase activity. It was found from the primary screening test result that only four isolates Trichoderma viride, Aspergillus niger, Aspergillus fumigatus and Fusarium oxysporum were shown large zone formation that meant they have great potential cellulase activity. Among these, Trichoderma viride and Aspergillus niger strains were showed highest enzymatic activity during the secondary screening, while Trichoderma viride generated the highest protein (89.51 µg/ml). Furthermore, these potential fungal strains will be useful for the organic municipal solid waste degradation.

Municipal solid waste leachate impact on metabolic activity of wheat (Triticum aestivum L.) seedlings.

Municipal solid waste (MSW) contains contaminants that could possibly leach out and pollute the soil, water sources. In this investigation, the MSW leachate toxicity was evaluated using wheat seedling plant bioassay. The eco-toxicity activities of leachate at several time intervals were explored, and the toxicity of these leachates on wheat (Triticum aestivum L.) seed germination and chlorophyll a and chlorophyll b (Chl a and Chl b) levels were determined. The findings showed that leachate can affect the metabolic activity of the wheat plant. Therefore, in order to protect the environment, the polluted leachate should be treated.

A preliminary report of indigenous fungal isolates from contaminated municipal solid waste site in India.

Municipal solid waste (MSW) containing harmful substances is a major concern in waste management and can cause adverse effects on diversity of fungi in soil. The main objective was to evaluate the fungal diversity inhabiting in the soil nearby MSW disposal site. The fungal strains were isolated in potato dextrose agar (PDA), media at temperatures 28 ± 1 °C by using standard serial dilution pour plate method, and appeared fungal colonies identified based on morphological characteristics. The overall most fungal diversity was found in soil sample collected from S5, followed by S4, S3, S1, and least in S2 site. A total of 24 fungal isolates recovered from the different MSW sites and Aspergillus sp., Fusarium sp., and Curvularia sp. genus has isolated from all the samples. In addition, the metal tolerance index performed because it needs to classify the fungus for their best use as potential agent for environmental protection. The metal tolerance outcomes revealed that both metals (cadmium and chromium) has appeared as the highest growth inhibitor for most strains and even fungal colonies did not propagate very well on the surface of media. Therefore, these findings suggest that the pre-adapted indigenous fungal isolates have proven remarkable tolerance ability to both metals. Furthermore, these highly metal-tolerant fungal strains are recommended for detail research or can use in pilot-scale bioremediation application to treat contaminated site.

Evaluating waste printed circuit boards recycling: Opportunities and challenges, a mini review.

Rapid generation of waste printed circuit boards has become a very serious issue worldwide. Numerous techniques have been developed in the last decade to resolve the pollution from waste printed circuit boards, and also recover valuable metals from the waste printed circuit boards stream on a large-scale. However, these techniques have their own certain specific drawbacks that need to be rectified properly. In this review article, these recycling technologies are evaluated based on a strength, weaknesses, opportunities and threats analysis. Furthermore, it is warranted that, the substantial research is required to improve the current technologies for waste printed circuit boards recycling in the outlook of large-scale applications.