Integrated solid waste management based on the 3R approach

Integrated solid waste management (ISWM) based on the 3R approach (reduce, reuse, and recycle) is aimed at optimizing the management of solid waste from all the waste-generating sectors (municipal, construction and demolition, industrial, urban agriculture, and healthcare facilities) and involving all the stakeholders (waste generators, service providers, regulators, government, and community/neighborhoods). This article discusses the concept of solid waste management (SWM). Initially, SWM was aimed at reducing the risks to public health, and later the environmental aspect also became an important focus of SWM. Recently, another dimension is becoming a critical factor for SWM, i.e., resource conservation and resource recovery. Hence, the 3R approach is becoming a guiding factor for SWM. On the one hand, 3R helps to minimize the amount of waste from generation to disposal, thus managing the waste more effectively and minimizing the public health and environmental risks associated with it. On the other hand, resource recovery is maximized at all stages of SWM. Lately, the new concept of ISWM has been introduced to streamline all the stages of waste management, i.e., source separation, collection and transportation, transfer stations and material recovery, treatment and resource recovery, and final disposal. It was originally targeted at municipal solid waste management (MSWM), but now the United Nations Environment Programme (UNEP) is promoting this concept to cover all waste generating sectors to optimize the level of material and resource recovery for recycling as well as to improve the efficiency of waste management services. The ISWM concept is being transformed into ISWM systems to replace conventional SWM systems. This article further discusses the implementation process for ISWM. The process includes a baseline study on the characterization and quantification of waste for all waste generating sectors within a city, assessment of current waste management systems and practices, target setting for ISWM, identification of issues of concern and suggestions from stakeholders, development of a draft ISWM plan, preparation of an implementation strategy, and establishment of a monitoring and feedback system. UNEP is assisting member countries and their cities to develop an ISWM plan covering all the waste generating sectors within a specific geographical or administrative area such as a city or municipality. This umbrella approach is useful to generate sufficient volumes of recycling materials required to make recycling industries feasible. This is also helpful for efficient reallocation of resources for SWM such as collection vehicles, transfer stations, treatment plants, and disposal sites. UNEP is assisting cities to develop and implement ISWM based on the 3R approach. These experiences could be useful for other countries to develop and implement ISWM to achieve improved public health, better environmental protection, and resource conservation and resource recovery.     

An investigation of anthraquinone dye biodegradation by immobilized Aspergillus flavus in fluidized bed bioreactor

Purpose

Biodegradation and biodecolorization of Drimarene blue K₂RL (anthraquinone) dye by a fungal isolate Aspergillus flavus SA2 was studied in lab-scale immobilized fluidized bed bioreactor (FBR) system.

Method

Fungus was immobilized on 0.2-mm sand particles. The reactor operation was carried out at room temperature and pH?5.0 in continuous flow mode with increasing concentrations (50, 100, 150, 200, 300, 500?mg?l^?1) of dye in simulated textile effluent on the 1st, 2nd, 5th, 8th, 11th, and 14th days. The reactors were run on fill, react, settle, and draw mode, with hydraulic retention time (HRT) of 24?C72?h. Total run time for reactor operation was 17?days.

Results

The average overall biological oxygen demand (BOD), chemical oxygen demand (COD), and color removal in the FBR system were up to 85.57%, 84.70%, and 71.3%, respectively, with 50-mg?l^?1 initial dye concentration and HRT of 24?h. Reductions in BOD and COD levels along with color removal proved that the mechanism of biodecolorization and biodegradation occurred simultaneously. HPLC and LC?CMS analysis identified phthalic acid, benzoic acid, 1, 4-dihydroxyanthraquinone, 2,3-dihydro-9,10-dihydroxy-1,4-anthracenedione, and catechol as degradation products of Drimarene blue K₂RL dye. Phytotoxicity analysis of bioreactor treatments provided evidence for the production of less toxic metabolites in comparison to the parent dye.

Conclusion

The present fluidized bed bioreactor setup with indigenously isolated fungal strain in its immobilized form is efficiently able to convert the parent toxic dye into less toxic by-products.     

Strategic thinking on sustainability: challenges and sectoral roles

This paper focuses on identified challenges for sustainable development across various sectors and the actions needed by different institutions and individuals for the achievement of a sustainable path. For finding solutions that impede sustainable development, emphasis is given to collaborative, inter- and trans-disciplinary problem-solving approaches. The ‘ecological modernization’ view is based on the belief that science and technology will result in continuous improvement in human welfare, while the emerging postmodern ‘ecological paradigm’ also emphasizes harmony with nature and other actors. Global societies are in the midst of a number of challenges: (1) implementation of existing and new hard- and soft-law instruments, (2) the degradation of natural resources, (3) an inadequate global mechanism for handling environmental and social responsibilities by the international community, (4) an unbalanced distribution of wealth, locally and internationally, (5) unethical and unsustainable business practices, (6) consequent unethical and unsustainable consumer practices, (7) selective application of ethical principles by rich countries and (8) the absence of norms of good conduct by powerful and wealthy peoples pertaining to sustainable development. Governments, civil societies, academicians, indigenous peoples, communities, businesses and international organizations need to become engaged in the formulation and enforcement of environmentally and ecologically sound development policies along with relevant research, education, training, awareness and a change in social values as provided in the Earth Charter to support actions for sustainable development.     

Preparation of antibodies and development of an enzyme immunoassay for determination of atrazine in environmental samples

An indirect competitive enzyme-linked immunosorbent assay (ELISA) has been developed and optimized for atrazine determination in soil at different depths (0-10, 10-20, and 20-30 cm) before and after 48 h of application, corn shoot and cow milk samples collected from Dina farm, Egypt. This assay was based on a specific polyclonal antibodies (PAb) raised by immunizing New Zealand rabbits with an immunogen prepared by coupling 3-{4-(ethylamino)-6-(isopropylamino)-1,3,5-triazine-2-yl} thiopropanoic acid to bovine serum albumin (BSA) via N-hydroxysuccinimide (NHS) active ester method. The sensitivity (estimated as IC?? value) was 17.5 μg mL?1 with a detection limit of 0.1 ng mL?1. The maximum atrazine concentration was found in soil especially in the deepest layer (325 and 890 μg kg?1 before and after application, respectively). Atrazine concentration in corn shoot was 333.28, μg kg?1 dry plant, while there was no detectable amount in milk. All samples screened by ELISA were validated by gas chromatography mass spectrometer procedure (GC/MS). Good correlation was achieved between the two methods (r = 0.997 for soil and 0.9814 for plant). This study demonstrates the utility and convenience of the simple, practical and cost-effective ELISA method in the laboratory for analysis of environmental samples. The method is ideal for the rapid screening of large numbers of samples in laboratories where access to GC/MS facilities, is limited or lacking.     

Effectiveness of novel and traditional treatments on the performance of incinerator bottom ash waste

Management of natural aggregate resources has become one of the most important challenges in construction, especially for high demand applications such as roads. Incinerator bottom ash (IBA), which is produced from burning domestic waste, has been considered a useful solution to the shortage of natural resources. In this research, IBA was mixed with limestone to produce an acceptable blend for use as a road foundation layer. Novel and traditional additives were adopted to improve the mechanical properties of IBA blends. The study focused on the treatment effect of additives on the mechanical characteristics of IBA blends under monotonic and cyclic triaxial stresses. The investigation evaluated fundamental material properties, including resilient modulus, initial Young's modulus and Poisson's ratio. Two nonlinear empirical models were adopted to depict the experimental resilient modulus results of the IBA blends. An approach has been proposed to predict realistic and representative values of resilient modulus for the material. In addition, a new relationship has been established between Young's modulus, resilient modulus and Poisson's ratio. Triaxial test results revealed that additives are more efficient with the control limestone blend than with the IBA blends. Novel additives, such as enzyme I and silica fume, produced a noticeable improvement in IBA properties in comparison to traditional additives.     

Particulate matters and gaseous pollutants in indoor environment and Association of ultra-fine particulate matters (PM1) with lung function

Environmental Science and Pollution Research - Real-time particulate matters (PM1, PM2.5, PM4, PM7, PM10, and TSP) with AEROCET 531S (USA), gaseous pollutants (NO2 and TVOC) with Aeroquel 500 gas...     

Adsorption and thermodynamic parameters of chlorantraniliprole and dinotefuran on clay loam soil with difference in particle size and pH

The behavior of chlorantraniliprole (CAP) and dinotefuran (DNF) insecticides was investigated in clay loam soil, a common type of the Egyptian soil. Effect of temperature, pH and particle size of the soil on the adsorption process was studied. Adsorption isotherm by bulk soil and its constituents; humic acid (HA), clay, silt and sand fractions was measured using batch equilibration technique. The results showed that the adsorption of the insecticides tested was significantly affected by the temperature and was a spontaneous interfacial process in the soil. Freundlich model accurately predicted the adsorption behavior of both insecticides. The interaction between soil and insecticides was endothermic and the highest adsorption for CAP and DNF was obtained at pH 9. However, the effect of pH on the adsorption of DNF was lower than that of CAP. Sorption of CAP and DNF on HA fraction was significantly greater than on clay fraction and bulk soil. In addition, the adsorption was significantly increased with particle size decrease. It could be inferred that the adsorption of CAP and DNF on clay loam soil was physical in nature and greatly influenced by the soil components, pH and temperature.     

Effect of dietary phytogenics (herbal mixture) supplementation on growth performance,nutrient utilization,antioxidative properties,and immune response in broilers

Environmental Science and Pollution Research - This experiment was conducted to study that effect of a phytogenics (herbal mixture) supplementation as alternative to antibiotics on the growth...     

An extensive review on restoration technologies for mining tailings

Development of mineral resources and the increasing mining waste emissions have created a series of environmental and health-related issues. Nowadays, the ecological restoration of mining tailings has become one of the urgent tasks for mine workers and environmental engineers all over the world. Aim of the present paper is to highlight the previous restoration techniques and the challenges encountered during the restoration of mine tailings. As it is a common practice that, before restoring of tailings, the site should be evaluated carefully. Studies showed that the mine tailings’ adverse properties, including excessive heavy metal concentration, acidification, improper pH value, salinization and alkalization, poor physical structure and inadequate nutrition, etc., are the major challenges of their restoration. Generally, four restoration technologies, including physical, chemical, phytoremediation, and bioremediation, are used to restore the mining tailings. The working mechanism, advantages, and disadvantages of these techniques are described in detail. In addition, selection of the suitable restoration techniques can largely be carried out by considering both the economic factors and time required. Furthermore, the ecosystem restoration is perceived to be a more promising technology for mine tailings. Therefore, this extensive review can act as a valuable reference for the researchers involved in mine tailing restoration.     

Experimental investigation of dust pollutants and the impact of environmental parameters on PV performance: an experimental study

The accumulation of dust pollution on the photovoltaic (PV) module can have a significant effect on the productivity and efficiency of PV systems in different locations in the world. Dust which accumulated over time on the PV module and is based on weather conditions led to the reduction in the effectiveness of solar cells. The aim of this research was to experimentally investigate the effect of the natural dust and the effects of environmental parameters on PV performance. The experiments were conducted to propose a model for the current, voltage, power and efficiency and to simulate the effect of environmental parameters on PV performance. The natural dust investigated consisted of different compounds: SiO₂ (45.53 %), CaO (24.62 %), Al₂O₃ (10.83 %), Fe₂O₃ (10.46 %), MgO (6.33 %), K₂O (0.87 %), TiO₂ (0.45 %), SO₃ (0.24 %), MnO₂ (0.21), Cr₂O₃ (0.23 %), SrO (0.13 %) and NiO (0.09 %). It was found that the most accurate correlation is a polynomial from seventh degree for current, voltage, power and efficiency, fourth degree for solar radiation and temperature, cubic degree for humidity and wind velocity. The coefficients of general model are 0.6343, 0.0110, 0.0 and 0.0001 for PV module, respectively, with 0.0011 fitting factor. The proposed model has been validated using models in the literature.