Solid industrial wastes and their management in Asegra (Granada, Spain)

Uncovering the recycling potential of industrial waste in Sri Lanka

The generation of industrial waste is mainly dependent on several factors, including the type of industry, production capacity, technology use and raw materials involved in the manufacturing processes. The present study is a cross-sectional study that was conducted with 580 industries under six industrial sectors in Sri Lanka in 2022. The main objective of this research was to investigate solid waste generation and estimate the recyclable fraction in the waste. Furthermore, this study calculated the prevailing recycling rate of each industrial sector and the waste generation per person employed in the sector. Industrial processes, the types and quantities of waste, waste disposal methods and management activities in terms of recycling and disposal were evaluated through a structured questionnaire and random field observations. The study identified that the composition of selected recyclable items was 16.7% of the total waste generated in the industrial sector. The prevailing rate of recycling in different sectors was as follows: manufacturing of food products (36.6%), manufacturing of beverages (82.3%), manufacturing of textiles (68.6%), manufacturing of chemical and chemical products (28.5%), manufacturing of rubber and plastic (46.5%) and manufacturing of metallic mineral products (17.8%) from the total generated recyclable material. The study further estimated the waste intensity (waste generation per unit of product output) of the industrial sectors as follows: 0.38 (manufacturing of food products), 0.36 (manufacturing of beverages), 0.27 (manufacturing of textiles), 0.26 (manufacturing of chemical and chemical products), 0.17 (manufacturing of rubber and plastic) and 0.16 (manufacturing of non-metallic mineral products).

Nickel and aluminium mixture elicit memory impairment by activation of oxidative stress, COX-2, and diminution of AChE, BDNF and NGF levels in cerebral cortex and hippocampus of male albino rats

This study evaluated nickel and aluminium-induced neurotoxicity, as a binary metal mixture. Twenty-eight male Sprague Dawley albino rats were weight-matched and divided into four groups. Group 1 (control) received deionized water. Group 2 and 3 received Aluminium (1 mg/kg) and Nickel (0.2 mg/kg) respectively, while Group 4 received Ni and Al mixture HMM three times a week orally for 90 days. Barnes maze tests was performed. Rats were sacrificed under pentobarbital anaesthesia, cerebral cortex and hippocampus were separated, and metal levels were measured using Atomic Absorption Spectroscopy (AAS). Malondialdehyde (MDA), catalase (CAT), glutathione content (GSH), superoxide dismutase (SOD), glutathione peroxidase (GPx), Brain Derived Neurotrophic Factor (BDNF), Nerve growth factor NGF, cyclo-oxygenase COX-2 and Acetylcholinesterase (AChE) were assayed using ELISA kits. Ni/Al binary mixture exposed rats showed a shorter latency period (though not significant) of 3.21 ± 1.40 s in comparison to 3.77 ± 1.11 (Ni only) and 3.99 ± 1.16(Al only). Ni/Al mixture gp had the lowest levels of Mg in both the hippocampus and frontal cortex when compared with the individual metals. In the hippocampus Al only exposed rats significantly showed p < 0.05 higher iron and Ca levels in comparison to Ni/Al mixture. Al alone significantly showed p < 0.05 lower levels of Fe but higher Ca than the Ni/Al mixture group. Exposure to Al only showed lower levels of BDNF in comparison to Ni/Al combination, whereas Ni/Al mixture gp had lower levels of NGF in comparison to the individual metals in the hippocampus. In the frontal cortex Ni only, group showed significantly lower BDNF in comparison to Ni/Al mixture whereas the mixture showed significantly lower NGF when compared with Al only group. There were higher levels of COX-2 in the Ni/Al mixture than individual metal treated rats in both hippocampus and frontal cortex. AChE levels in the Ni/Al mixture group was higher than Ni or Al only gps in the hippocampus whereas in the frontal cortex, Ni/Al exposed rats showed significantly lower AChE levels in comparison to Al only group. Ni, Al and Ni/Al mixture exhibited memory impairment by activation of oxidative stress, COX-2, and diminution of AChE, BDNF and NGF levels in cerebral cortex and hippocampus. The BDNF-COX-2 AChE signalling pathway may be involved in the neurotoxicity of Ni and Al.

Mechanical Properties, Crack Width, and Propagation of Waste Ceramic Concrete Subjected to Elevated Temperatures: A Comprehensive Study

Waste ceramic concrete (WOC) made from waste ceramic floor tiles has several economic and environmental benefits. Fire is one of the most common disasters in buildings, and WOC is a brittle construction material; therefore, the mechanical properties of WOC structures under high temperatures should be considered. According to previous studies, hybrid fiber can further reduce damage to concrete under high temperatures. Meanwhile, crack width and propagation are among the key characteristics of concrete materials that need to be considered, but few studies have focused on their behavior when subjected to elevated temperatures. The new concrete materials proposed by the authors are WOC and WOC-Hybrid. WOC was prepared with Natural Coarse Aggregates (NCA), Natural Fine Aggregate (NFA), Ordinary Portland Cement (OPC 43 grade), and ceramic waste tiles with 20% replacements for coarse aggregates, 10% replacements for fine aggregates, and 10% replacement for cement. In contrast, WOC-Hybrid was prepared with the addition of hybrid fiber (1% crimped steel fiber and 1% polyvinyl alcohol fiber) in WOC. The specimens were exposed to temperatures of 100–300 °C, and then the specimens were tested for tensile and compressive strength. The present study aims to find a new method to improve concrete resistance to elevated temperatures at the lowest costs by experimental and computational analysis via machine learning models. The application of machine learning models such as artificial neural networks (ANN) and multiple linear regression (MLR) was employed in this study to predict the compressive and tensile strength of concrete. The linear coefficient correlation (R²) and mean square error (MSE) were evaluated to investigate the performance of the models. Based on the experimental analysis, the results show that the effect of hybrid fiber on the crack width and propagation is greater than that on the crack width and propagation of WOC and PC after exposure to high temperatures. However, the enhanced effect of hybrid fiber on the mechanical properties, rack width, and propagation decreases after subjecting it to a high-temperature treatment, owing to the melting and ignition of hybrid fibers at high temperatures. Regarding the computational analysis, it was found that the developed MLR model shows higher efficiency than ANN in predicting the compressive and tensile strength of PC, WOC, and WOC-Hybrid concrete.

Colour Change of Sustainable Concrete Containing Waste Ceramic and Hybrid Fibre: Effect of Temperature

Construction and demolition (C&D) waste was considered as zero value materials and, as a result, most C&D waste materials ended up in landfills, eventually constituting environmental issues. Therefore, it is important to explore the potential of such C&D waste materials for concrete production. Thus, this research effort aims to find a new method to improve sustainable concrete properties exposed to elevated temperatures at the lowest costs and identify the relationship between temperature change and a change in colour in a heat-exposed concrete structure. Therefore, this study explored the behaviour of three types of concrete: plain concrete (PC), waste ceramic optimal concrete (WOC), and waste ceramic optimal concrete reinforced by hybrid fibre (WOC-Hybrid) in ambient and elevated temperature. The study shows that colour change in a concrete structure exposed to high temperature has a consistent relationship, where it has been found that the colour alteration is of great interest because its appearance usually coincides with the onset of a significant loss of concrete strength as a result of elected temperatures. Overall, it can be considered that waste ceramic materials reinforced by hybrid fibres can be used for concrete production, and by doing so, the negative impact of these wastes on the environment can be controlled as well as fortify the mechanical properties.

Associations of residential and occupational history with the distribution of persistent pollutant mixtures in adipose tissue samples

This research aims to explore clusters of a mixture of 15 Persistent Toxic Substances (PTSs) in the adipose tissue of 227 individuals of an adult cohort from Granada Province (Southern Spain). Information about residence and occupation during participants lifetime was gathered by means of validated questionnaires. Clusters of pollutants in the study population were identified by Principal Component Analyses (PCA). PCA analyses revealed three major clusters of pollutants: PC1, representing predominantly an assortment of metal(loid)s, namely aluminium, arsenic, chromium, nickel and lead; PC2, including mostly Organochlorine Pesticides (OCPs), such as HCB, β-HCH and p,p'-DDE; and PC3, gathering mainly a mixture of Polychlorinated Biphenyls (PCB-138, PCB-153 and PCB-180) and metals (cadmium, cobalt and chromium). The patterns of distribution of individual pollutants and their mixtures were explored through Geographic Information Systems and multivariable linear regression models. Living in rural areas was associated with decreased levels of the mixture of PCBs and metals. Residents of industrial and heavy traffic areas showed increased levels of the mixture of metal(loid)s. Those living in rural and semi-rural areas at recruitment had decreased levels of the OCP mixture. Occupational history related to agriculture and food industry was associated with increased levels of the mixture of metal(loid)s, whereas those who had been involved in motor and industrial activities showed increased levels of the OCP mixture. Participants who had worked in cleaning and housekeeping activities for long periods showed decreased levels of the mixture of PCBs and metals. Our research revealed suggestive clusters of exposure, that emphasized the need for further epidemiological studies to address the effect of environmental pollutants from a mixture perspective. Results also highlight the potential of adipose tissue as a matrix for exposure assessment to combinations of different families of contaminants.

Evaluation of industrial wastes management practices: Case study of the Savojbolagh industrial zone, Iran

The main objective of this research was to investigate the waste characteristics and management activities in the Savojbolagh industrial zone, Iran, in order to rank the active industries from environmental perspectives using an innovative index. First, the industrial categories with over 50 employees were identified and classified according to their production process. Then, 54 industries were selected and all industrial processes, the types and quantities of products, per capita industrial waste generation, physical analysis and management activities in terms of minimisation, storage, processing, recycling and disposal were evaluated. The required data were obtained through questioners, interviews and field observations. A scoring system was prepared for evaluation of environmental status of waste management practices. Results indicated that the total industrial waste generation rate was 67,258 kg d^-1, in which 4528 belonged to hazardous waste. Furthermore, the per capita waste generation rate was 5.51 kg d^-1. Plastic, paper and cardboard and metals constituted the most fractions of wastes, respectively. Food and beverage, metallic and chemical/plastic industries were the biggest waste generators. Metallic industries with total score of 502.5 and non-metalic-mineral industries with the total score of 114 were categorised as the best and worst industries in terms of waste management practices.

Survey of wastes management status of Khayyam industrial estate in Neyshabur City (Northeastern Iran) in 2017

The extent of environmental pollution caused by wastes in industrial estates has attracted the attention of scientific and executive resources of the world to the correct disposal and recycling of these materials. This study is a cross-sectional descriptive study which was conducted in the Khayyam industrial estate of Neyshabur in 2017. To survey the management of industrial wastes status, based on the fieldwork, different days were selected in each week to complete the questionnaire designed by the Iranian Environmental Protection Agency. The completion of questionnaires was started from a specific path daily. Finally, the collected data were entered into the SPSS 18 software and were analyzed to determine the wastes management status of the industrial estate. Excel software was used to draw the charts. The total industrial wastes produced in Khayyam industrial estate were 3555 tons per year, waste per capita was 2177.9 g per day per worker. Most existing industries in Khayyam industrial estate were food and pharmaceutical, which include 43.94%. Recycling (79.55%) and burial (14.39%) were the first and second levels of final disposal of industrial wastes. The results of this study show that the wastes management of Khayyam industrial estate has a relatively acceptable situation. Unfortunately, the waste dumping in the open space can lead to the generation of moisture and the release of pollutants to the environment and cause pollution of water and soil through leakage as well as damage to workers. Proper control and correct management are essential for maintaining the health and protection of the environment.

Waste generation and utilisation in micro-sized furniture-manufacturing enterprises in Turkey

The number of small-scale businesses within most national economies is generally high, especially in developing countries. Often these businesses have a weak economic status and limited environmental awareness. The type and amount of waste produced, and the recycling methods adopted by these businesses during their operation can have negative effects on the environment. This study investigated the types of waste generated and the recycling methods adopted in micro-sized enterprises engaged in the manufacture of furniture. An assessment was also made of whether the characteristics of the enterprise had any effect on the waste recycling methods that were practised. A survey was conducted of 31 enterprises in the furniture industry in Gumushane province, Turkey, which is considered a developing economy. Surveys were undertaken via face-to-face interviews. It was found that medium-density fibreboard (MDF), and to a lesser extent, chipboard, were used in the manufacture of furniture, and two major types of waste in the form of fine dust and small fragments of board are generated during the cutting of these boards. Of the resulting composite board waste, 96.9% was used for heating homes and workplaces, where it was burnt under conditions of incomplete combustion. Enterprises were found to have adopted other methods to utilise their wastes in addition to using them as fuel. Such enterprises include those operating from a basement or first floor of a building in the cities, those continuing production throughout the year, those in need for capital and those enterprises not operating a dust-collection system.

Reutilisation-extended material flows and circular economy in China

Circular economy (CE), with its basic principle of Reduce, Reuse, and Recycle, has been determined as the key strategy for the national development plan by the Chinese government. Given the economy-wide material flow analysis (EW-MFA) that leaves the inner flow of resource reutilisation unidentified, the reutilisation-extended EW-MFA is first introduced to evaluate and analyse the material input, solid waste generation, and reutilisation simultaneously. The total amount of comprehensive reutilisation (CR) is divided into three sub-flows, namely, reutilisation, recycle, and reuse. Thus, this model is used to investigate the resource CR in China from 2000 to 2010. China's total amount of CR and its sub-flows, as well as the CR rate, remain to have a general upward trend. By the year 2010, about 60% of the overall solid waste generation had already been reutilised, and more than 20% of the total resource requirement was reutilised resource. Moreover, the growth patterns of the CR sub flows show different characteristics. Interpretations of resource reutilisation-related laws and regulations of CE and the corresponding policy suggestions are proposed based on the results.