This study presents the natural dye recovery from various biodegradable temple and household wastes. The raw material for colour extraction consisted residual flowers and garlands from various temples as well as onion and vegetables peels from vegetable markets, university hostels, and households, which were washed, dried, crushed, and sieved. The extracted natural colours were produced by means of ultra-sonication, and were dried in the spray drier, being characterized by FT-IR and UV-Vis Spectrophotometers. They were used to dye various fabrics such as cotton, silk, and wool, not to mention different mordents. It was found out that the remaining residue, left after dye extraction, was rich in nutrients, hence, it could be further used as the resource material, itself. As a result, we explored these residual wastes for vermicomposting and biochar production, which can be further employed as an organic fertilizer for agriculture. Overall, the present waste management approach will lead to a closed-loop environmental management through waste reduction and reutilization. It will also provide value-added materials for economic gains from waste. Thus, it can be promoted as a potential mechanism to maintain the environmental sustainability at wider scales.

Jajarm Alumina Plant, the only Alumina powder producer in Iran, generates 500,000 tons of red mud annually. The commonest method for final disposal of red mud in Iran is Tailing dam which is neither cost-effective nor environmentally-friendly. The main objective of this study is to evaluate the possibility of red mud recovery to be used for stabilization of loose soils. Red mud samples have been collected from tailing dam of Jajarm Alumina Plant to be characterized, using X-Ray Fluorescence (XRF). The soil stabilizer has been made by mixing red mud, steel slag, sodium metasilicate, and sodium hydroxide. In order to study the effect of soil stabilizer, five soil samples have been prepared which contain clay, sand, and wind-blown sand ranging from zero to 4 millimeters. Findings show that adding soil stabilizer with red mud significantly enhances compressive strength of soil samples (4.2, 18.2, 5.4, 4, and 4.1 in S1 to S5 samples, respectively). Also the results demonstrate that the red mud, produced from Aluminum industry in Iran, might be successfully used to stabilize loose soils, thereby enhancing their compressive characteristics, reducing environmental issues associated with uncontrolled disposal of such wastes as well as promoting integrated solid waste management strategies.

Plastic usage increases year by year, and the growing trend is projected to continue. However as of 2017, only 9% of the 9 billion tons of plastic ever produced had been recycled leaving large amounts of plastics to contaminate the environment, resulting in important negative health and economic impacts. Curbing this trend is a major challenge that requires urgent and multifaceted action. Based on scientific and gray literature mainly published during the last 10 years, this review summarizes key solutions currently in use globally that have the potential to address at scale the plastic and microplastic contaminations from source to sea. They include technologies to control plastics in solid wastes (i.e. mechanical and chemical plastic recycling or incineration), in-stream (i.e. booms and clean-up boats, trash racks, and sea bins), and microplastics (i.e. stormwater, municipal wastewater and drinking water treatment), as well as general policy measures (i.e. measures to support the informal sector, bans, enforcement of levies, voluntary measures, extended producer responsibility, measures to enhance recycling and guidelines, standards and protocols to guide activities and interventions) to reduce use, reuse, and recycle plastics and microplastics in support of the technological options. The review discusses the effectiveness, capital expenditure, and operation and maintenance costs of the different technologies, the cost of implementation of policy measures, and the suitability of each solution under various conditions. This guidance is expected to help policymakers and practitioners address, in a sustainable and cost-efficient way, the plastic and microplastic management problem using technologies and policy instruments suitable in their local context.

International audience | Abstract Fifty million cubic meters of marine sediments are dredged each year in France in order to maintain harbor activities and sustain the economy of littoral territories. Because of anthropogenic activities in and around harbors, sediments can contain significant amounts of chemical and organic pollutants whose behavior during dredging must be addressed in order to avoid releasing risks for humans and the environment. French regulations come to govern the management of dredged sediments, considering them “safe” and possible to be dumped at sea or “contaminated” and needed to be treated on land as waste. In recent years, new constraints have been pushed toward the management of land. This management is, however, challenging as few channels are proposed to reuse marine sediments, and elimination appears to be economically and environmentally unsustainable. This study provides an overview of the technical and regulatory aspects related to dredged marine sediment management in France and aims to identify and discuss the limits of their valorization. Dredged sediments are mainly composed of particles with heterogeneous grain size, some being known for many applications such as building materials and growing media. However, several reasons have been put forward to explain why these particles are not reused when extracted from dredged sediments. Several technical, socio-economic, and regulatory obstacles explain the low demand for dredged sediments. This demand can be stimulated by government incentives and a good regulatory framework. National regulations could help streamline their reuse by removing their “waste” status and creating a regulated market for dredged sediment.

In recent years, pollution of antibiotics and heavy metal has often been reported in organic wastes. Saprophytic insects have been recorded as biological control agents in organic waste management. During organic waste conversion, the intestinal bacteria of the saprophytic insects play an important role in digestion, physiology, immunity and prevention of pathogen colonization. Black soldier fly (BSF) Hermetia illucens has been widely used as saprophytic insects and showed tolerance to sulfonamides (SAs) and cadmium (Cd). Diversity and changes in gut microbiota of black soldier fly larvae (BSFL) were evaluated through 16S rRNA high-throughput sequencing, and a decrease in diversity of gut microbiota along with an increase in SAs stress was recorded. Major members identified were Actinomycetaceae, Enterobacteriaceae, and Enterococcaceae. And fourteen multi-resistance Klebsiella pneumoniae strains were isolated. Two strains BSFL7-B-5 (from middle midgut of 7-day BSFL) and BSFL11-C-1 (from posterior midgut of 11-day BSFL) were found to be low-toxic and multi-resistance. The adsorption rate of SAs in 5 mg/kg solutions by these two strains reached 65.2% and 61.6%, respectively. Adsorption rate of Cd in 20 mg/L solutions was 77.2% for BSFL7-B-5. The strain BSFL11-C-1 showed higher than 70% adsorption rates of Cd in 20, 30 and 40 mg/L solutions. This study revealed that the presence of multi-resistance bacterial strains in the gut of BSFL helped the larvae against SAs or Cd stress. After determining how and where they are used, selected BSFL gut bacterial strains might be utilized in managing SAs or Cd contamination at suitable concentrations in the future.

Modification of biochar by low-cost iron sources has gained increasing attention to improve pollutants removal performance and reduce production costs compared to conventional chemical modifications. While such iron sources generally have complex compositions, their effects on properties of the iron-biochar composite are not well investigated. This study produced an iron-biochar (RBC) composite from co-pyrolysis of incinerated sewage sludge ash (ISSA) and peanut shell, and examined the role of silica with widespread existence in ISSA and other low-cost iron sources on properties of the iron-biochar composite relevant to As(III)/As(V) removal. Silica was found to react with iron during the pyrolysis process at 850 °C and formed iron silicon at the expense of producing zero valent iron and Fe₃O₄ which resulted in a poorer removal efficacy for As(III) and As(V) compared to the iron-biochar (FBC) made from pure Fe₂O₃ and peanut shell. Moreover, a high leaching of reactive silica from RBC was observed which affected the formation of corrosion products of ZVI and competed with arsenic for active adsorption sites. Despite this, RBC still exhibited a maximum adsorption capacity of 17.44 and 57.56 mg/g towards As(III) and As(V) respectively at pH 3.0. Overall, this study provides an interesting insight into upcycling ISSA into useful media for sorptive removal of arsenic from aqueous solutions.

Open waste burning emissions constitute a significant source of air pollution affecting human health in India. In regions where cleaner fuels have displaced solid biofuel usage, open waste burning is rapidly becoming one of the largest sources of airborne human class-I-carcinogens and particulate matter. As the establishment of waste management infrastructure in rural India is likely to take years, we explore whether health-relevant emissions can be reduced by legalizing the burning of dry non-biodegradable waste in improved devices. We measure the emission factors of 76 VOCs, CH₄, CO, and CO₂ from different types of waste burned in two different improved devices, a burn basket and a local water heater. Based on our experiments, we create four “what-if” intervention scenarios to assess the improvement of air quality due to the emission reductions that can be accomplished by four management strategies. We find that substituting the traditional, more polluting water heating fuels with dry plastic waste across rural India can reduce primary emissions (e.g., −29 Ggy⁻¹ for benzene) and ozone formation potential (−2960 Ggy⁻¹) from open waste burning. When dry waste is used in lieu of more polluting fuels, and its burning serves a purpose, the net class-I-carcinogen benzene emissions, would be halved compared to the present. The change in emissions for the class-I carcinogen 1,3-butadiene would become net negative. This happens because the emissions avoided when part of the solid biofuel currently used in rural India is replaced by plastic waste (4.1 (1.2–4.1) Ggy⁻¹) exceed the waste burning emissions of this compound (3 (1.2–3.7) Ggy⁻¹) by so much, that residential sector emission reductions offset all waste burning emissions including those of landfill fires. Our study demonstrates that India's air quality can be improved by permitting and promoting the use of dry packaging waste in lieu of traditional biofuels and by promoting improved burning devices.

It is estimated that approximately 0.4% of the total leachate produced in a landfill is destined for treatment plants, while the rest can reach the soil and groundwater. In this context, this study aimed to perform leachate toxicity evaluations through immune system cytotoxic assessments, genotoxic (comet assay) appraisals and antioxidant system (superoxide dismutase - SOD; catalase - CAT, glutathione-S-transferase - GST; reduced glutathione - GSH and metallothionein - MT) evaluations in Eisenia andrei earthworms exposed to a Brazilian leachate for 77 days. The leachate sample contained high organic matter (COD - 10,630 mg L⁻¹) and ammoniacal nitrogen (2398 mg L⁻¹), as well as several metals, including Ca, Cr, Fe, Mg, Ni and Zn. Leachate exposure resulted in SOD activity alterations and increased CAT activity and MT levels. Decreased GST activity and GSH levels were also observed. Antioxidant system alterations due to leachate exposure led to increased malondialdehyde levels as a result of lipid peroxidation after the 77 day-exposure. An inflammatory process was also observed in exposed earthworms, evidenced by increased amoebocyte density, and DNA damage was also noted. This study demonstrates for the first time that sublethal effect assessments in leachate-exposed earthworms comprise an important tool for solid waste management.

The industrial production of insects for waste management or as a protein source is becoming vital to our society. Large volumes of manure are produced by concentrated animal facilities around the globe that must be managed, utilized, and disposed of properly. Flies offer a partial solution with their abilities to reduce these wastes and heavy metal pollutants. Meat and crop proteins are being supplemented by insect proteins for many feeds across the globe, yet science-based studies behind the mass-rearing of insects are still in their infancy. In the current study, the percent change in the composition of nutrients, heavy metals, and fiber, in dairy, poultry, and swine manure degraded by either black soldier fly (BSF) or house fly (HF) larvae was explored. Pre-digested and post-digested manure samples were collected from four independent studies that differed in production scale (number of larvae and feeding regimen): 1) BSF small-scale (100 larvae fed incrementally), 2) HF small-scale (100 larvae fed incrementally), 3) BSF large-scale (10,000 larvae fed a single time), and 4) HF large-scale (4,000 larvae fed a single time). Results indicate that nitrogen is a key nutrient impacted by larval digestion of manure by both species, regardless of scale. However, scale significantly impacted reductions of other nutrients, as did the type of manure in which the insects were reared. Ultimately, this study demonstrated that manure type and rearing scale impact the ability of BSF and HF larvae to reduce nutrients and heavy metals in manure, and thus insect management procedures need to be congruent with production emphases of the insects for waste management or protein products. Failure to take scale into consideration could lead to inaccurate assumptions related to industrialized efforts on this topic.