Hazardous Waste Research Articles

Discussion on the applicability and mechanism of phosphate-based geopolymers used for cadmium and cadmium-lead heavy metals solidification/stabilization

Lead (Pb2+) and cadmium (Cd2+) are common heavy metal pollution, which is harmful to humans and animals. However, the diffusion rate of heavy metal ions moves faster in acidic environment, there are a large number of acidic heavy metal polluted soil in China, but the conventional binders are not effective to deal with them. Phosphate-based geopolymers (PGEOs) are acidic materials, and have excellence mechanical properties in acidic environment and solidification/stabilization (S/S) effect on Pb2+, but the applicability of PGEOs to Cd, Pb and Cd composite pollution is not clear. Therefore, this study discusses the applicability of PGEOs fabricated from fly ash (FA) and aluminum dihydrogen phosphate (ADP) as activator for S/S treatment of Cd, Pb-Cd composite pollution. Results show that the influence of Cd2+ and Pb2+ on the compressive strength of PGEOs was inconsistent, as the Cd2+ content raised, the compressive strength reduced slightly at 7 and 14 days, but it did not change basically at 28 days. However, the compressive strength rose firstly and then declined with an increase in Pb-Cd content when partial Pb2+ was used to replace Cd2+. The compressive strength of PGEOs with a Pb-Cd content of 0.6 % reached maximum (11.45 MPa), exceeding the compressive strength of PGEOs containing Cd2+. Moreover, the PGEOs presents an excellent stabilization effect on Pb2+, but poor effect on Cd2+. The Pb2+ leaching concentration meet the hazardous solid waste identification criteria (<5 mg/L), but the Cd2+ leaching is high and is more than 1 mg/L. Furthermore, the compressive strength of PGEOs had a good correlation with pH and EC. The S/S mechanism of PGEOs for Pb2+, Cd2+ includes physical adsorption, encapsulation, and chemical precipitation. However, Pb2+ involved in the geopolymerization process, while Cd2+ can not participate in the structure formation, so the PGEOs have a poor S/S effect. Therefore, it needs to be further improved when using PGEOs to stabilize acidic Cd2+ contaminated soil.

GREEN MARKETING: A STUDY OF CONSUMERS’ PURCHASING BEHAVIOR OF SELECTED ECO-FRIENDLY PRODUCTS

The phrase "green products" is widely used to describe products and services that try to protect or enhance the environment during manufacture, use, or disposal through resource conservation and decreased use of hazardous chemicals, pollution, and waste. The Present study is on the subject of green consumer purchase behavior. This study explores the awareness and knowledge of Green Products. After consumers realized how their purchasing decisions, directly and indirectly, impacted the environment and their health, they began making more green purchases. Most studies that analyze it don't clearly define any particular product categories, such as organic food, green clothing, green electronics, green cleaning trends, ethical personal accessories, reusable containers, eco-friendly home goods, green cosmetics or organic personal care, green furniture, etc. Contrary to general green products, different product categories have different factors that influence consumer choice. Therefore, the paper aims to perform a complete holistic review of the fragmented and divergent studies on specific product categories. The purpose of consumer behavior research on green issues is to identify the rules that govern green consumption and make specific suggestions for promoting green consumption. Each sustainability value should come from home.

Response surface methodology was used to optimize the defluorination process of steam-enhanced microwave roasting waste cathode carbon

As a typical hazardous solid waste, improper treatment of waste cathode carbon (WCC) will cause great harm to animals and plants and their living environment. In order to make the treatment of WCC more simple, efficient and clean, this paper mainly adopts the method of microwave roasting and introducing water vapor to make the fluoride in WCC melt at high temperature and be absorbed by water vapor. The effects of water flow rate, reaction temperature, reaction time, material particle size and other important factors on the defluorination efficiency of WCC were studied by single factor experiment. In this paper, the response surface method (RSM) was used to obtain and verify the best results of the experiment, and the optimum process conditions of water vapor enhanced microwave roasting WCC defluorination were determined: the reaction temperature was 1100 °C, the reaction time was 2.8 h, and the water flow rate was 3.2 mL·min−1. Under this condition, the defluorination effect of WCC is the best. The predicted value of defluorination efficiency of WCC is 99.85 %, and the actual value is 99.8 %.

Recovery of cadmium, lead, strontium and zinc from jarosite waste by using a combinatory approach of bioleaching and acid leaching

ABSTRACT Metallurgical processes commonly generate substantial volumes of hazardous waste, and the extraction of zinc is no exception, yielding a byproduct known as jarosite. This study aims to establish an environmentally conscious and economically viable method for recuperating residual metals from jarosite waste. Comprehensive morphological and physico-chemical characterisation of jarosite was performed using XRD, FTIR, SEM and EDS. To facilitate the selective biorecovery of cadmium, lead, strontium and zinc, Shewanella putrefaciens was employed. The efficacy of biorecovery was systematically assessed using both solid-state and liquid-state leaching methodologies. The results indicate that liquid-state leaching outperformed solid-state leaching for all four heavy metal ions. Notably, biotreated jarosite demonstrated markedly superior metal recovery (Cd, Pb, Sr and Zn) compared to non-biotreated jarosite. This investigation advocates for a hybrid approach, involving bioleaching followed by acid treatment, as a more efficacious strategy for the sustainable recovery of heavy metals from jarosite-like waste. These findings not only underscore the potential of environment-friendly biorecovery techniques but also offer a promising avenue for enhancing the ecological sustainability of waste management practices within the metallurgical industry.

Mineralogy of Zinc and Lead Metallurgical Slags in Terms of Their Impact on the Environment: A Review

This paper presents the results of a study of the mineralogical and chemical composition of zinc and lead metallurgical slags. These slags contain numerous elements, including toxic metals, which form conglomerates or multiphase intergrowths. The phase composition of slags is one of the main factors that determine their behaviour in weathering environments, that is, their ability to release metals when exposed to atmospheric factors. In this paper, the release of elements from slags and their mobility in a hypergenic environment is determined based on the results of leachability tests and on geochemical modelling, thus assessing the environmental impact of landfilled slags. The elements released from slags in the largest quantities are zinc and lead. Zn is leached out over a long period of time. It was found that after 12 years, the concentration of Zn in the eluate exceeds by 40 times the permissible value of 200 mg/kg for hazardous waste. The degree of leaching of lead from slags as a function of time (after 12 years), despite its significant solubility in water, is much lower than the degree of leaching of zinc. The most mobile phase components of slags in the studied hypergenic environment are the lead phases (anglesite and galena) and, to a lesser extent, the zinc phases (sphalerite and willemite). Anglesite and galena in almost the entire Eh-pH range, along with admixtures of elements, decompose into ionic forms: PbCl42−, Pb2+, and PbOH+. Sphalerite in the soil and water environment (oxidizing and acidic conditions) will decompose into the mobile ionic form Zn2+. Willemite, which is resistant to weathering, will undergo similar decomposition. It can therefore be assumed that the carriers of toxic metals are primarily lead sulphides and sulphates, zinc sulphides, and, less frequently, zinc, lead, and iron oxides.

Thermal evolution of mercury from waste rare earth phosphor: Effect of thermal treatment conditions and kinetic analysis

Waste phosphor (WP) from fluorescent lamp is a hazardous waste and an important secondary resource for recycling mercury and rare earths. To avoid mercury pollution during rare earth recovery, it is necessary to conduct deep mercury removal before rare earth recovery. However, the mechanism of mercury removal in WP is not clear, which restricts the progress of efficient mercury removal methods. Effects of treatment temperature and time on thermal evolution of WP were analyzed by different characterization methods. Model-free, model-fitting and z(α) master plots method are used in combination to explain the complex mechanism of mercury removal in WP. The mechanism of mercury removal will change gradually with the process of mercury removal. The average Eα for mercury removal is 100.76 kJ/mol and 190.36 kJ/mol at conversion α (i.e. mercury removal efficiency) of 0.1–0.3 and 0.3–0.9, respectively. Simple mercury compounds are decomposed at α less than 0.3 (∼600 °C), according with the model of random nucleation and subsequent growth. A large amount of tightly combined mercury is released rapidly at α of 0.3–0.75 (600–700 °C), ascribing to the decomposition of carbonate and the structure transformation of silicon oxide. The process mechanism gradually change from 1D/2D diffusion to 3D diffusion, increasing the mass transfer resistance of mercury diffusion. Thermal desorption of residual bound mercury at α larger than 0.75 (∼700 °C) is controlled by phase boundary reaction. More efficient mercury removal effects can be obtained by adding additives to roasting. The results are beneficial to the research of deep mercury removal methods of WP.

Selective adsorption of methylene blue dye by a flocculation sludge-derived adsorbent prepared by carboxymethyl chitosan-based flocculants

The flocculation of dyeing wastewater generated a large amount of sludge that was often disposed as refractory hazardous waste. The resource utilization of flocculation sludge was of great significance in terms of low treatment cost of sludge, low environmental risk and high usage efficiency of reactive dyes. Herein, a flocculation sludge-derived (FSD) adsorbent was prepared via cross-linking of flocculation sludge yielding by carboxymethyl chitosan-based flocculants and dyes. FSD adsorbent had excellent selective adsorption performance for methylene blue (MB) treatment. The highest removal rate of MB and adsorption capacity of FSD adsorbent were 96.48 % and 354.7066 mg/g, attributing to its rich functional groups, negative charges and special micropore structure. FSD adsorbent owned the favorable regeneration efficiency and stability. Its removal rate of MB was still above 71.8 % after 6 regeneration-adsorption cycles. Its leaching rate of dyes was only 0.0016 mg/mg that was rather lower than common dried flocculation sludge. The adsorption processes of FSD adsorbent were complex in accordance with its characteristics, adsorption isotherms, adsorption kinetics and theoretical calculation. Multiple adsorption mechanisms were present in the treatment of dyeing wastewater by FSD adsorbent. The resource utilization of flocculation sludge, as adsorbents, was a potential candidate in field application.

Selective extraction of lithium and solidified fluoride from overhaul slag by the calcium sulfate roasting and water leaching

Overhaul slag is a hazardous waste which is from the process of aluminum electrolysis industry. In this work, a technology of calcium sulfate roasting and water leaching was developed to dispose of overhaul slag. The effects of roasting and leaching parameters were investigated in detail. Under the optimal roasting conditions, the fluorine could be stably solidified into CaF2, and lithium could be converted into soluble NaLi(SO4). The roasted clinker was then subjected to water leaching for the selective extraction of lithium. About 99.74 % of lithium was extracted and 99.82 % of fluoride was solidified by the leaching process under the optimal leaching conditions. After water leaching, the concentration of lithium can reach 2.3 g/L. XRD analysis shows that the main phases of the aqueous solution after evaporation and crystallization are NaLi(SO4) and Na2SO4, and a small amount of impurities can be further removed and concentrated to prepare Li2CO3. The main components of leaching slag are C, Al2O3 and CaF2, which can be used as fast setting cement. The process proposed in this paper is not limited to the recovery of high-value lithium from overhaul slag, and can be applied to the extraction of other valuable waste substances in aluminum industry.

H2O2 oxidation – CaO precipitation pretreatment combining forward osmosis for electroless nickel spent tank liquid (ENSTL) reduction

ABSTRACT The electroless nickel spent tank liquid (ENSTL), as a typical hazardous waste, contains a variety of refractory organic substances as well as heavy metals and inorganic salts. Generally, ENSTL is delegated for disposing by qualified hazardous waste disposal departments in China. However, the temporary storage, transportation, and higher entrusted disposal expenses increase the burden on enterprises producing the hazardous ENSTL. This paper explored an oxidation/precipitation pretreatment and forward osmosis (FO) combined process for ENSTL reduction. 400 mmol/L Hydrogen peroxide and 5.0 wt% calcium oxide were selected as the optimal pretreatment in order to minimize the osmotic pressure of ENSTL, by which the conductivity was significantly reduced from 50.8 mS/cm to 26.8 mS/cm. As a result, the concentrating factor (N) could be dramatically increased from 2.45 by the direct FO to 8.71 by the combined system. Accordingly, the average water flux during the 24 h concentrating cycle increased from 2.47 L/(m2·h) to 4.56 L/(m2·h). TOC rejection rate decreased from 90.23% to 84.39% due to the transformation of organic matter forms by the chemical oxidation during the pretreatment. Meanwhile, TP, Ni and NH4 + rejection rates decreased to a certain extent, which may related to the mitigation of membrane fouling by the pretreatment.

Isolation and Identification of Mercury-Resistant Fungi as Bioremediation Agents from Gold Mining

To overcome the pollution problem due to the accumulation of heavy metal Hg, a clean-up or remediation effort is needed from the former landfill for hazardous and toxic waste. In this research, bioremediation experiments will be conducted by inoculating fungi culture that is already known to have the potential to absorb heavy metals Hg. Samples of soil contaminated with heavy metals Hg taken from the tailings of gold mining owned by the people in Kertajaya Village, Simpenan District, Sukabumi Regency. The stages of this study consisted of isolation of fungi, purification and morphology of fungi isolate, screening of fungi isolate, qualitative screening of fungi for ligninolytic activity (laccase), and molecular identification of the isolated fungi. The results of the screening showed that three isolates of potential fungi coded M.2, M.10, and M.13 were able to grow with a mercury concentration of 350 ppm, while one isolate coded R4.28 reached a concentration of 1000 ppm. In addition, isolate M.2 was selected as the best strain compared to isolates M.10, M.13, and R4.28 for the qualitative test of laccase production in ligninolytic enzymes. Based on the molecular analysis of the 18S rRNA gene, M.2 isolates were similar to Trichoderma yunnanense, which was strengthened by a similarity value of 99.66%. Isolate R4.28 was similar to Penicillium soli, which was strengthened by a similarity value of 99.32%.

Green transformation of oily sludge through geopolymer: Material properties and hydration mechanisms

Oily sludge (OS) is a kind of hazardous waste generated from the petrochemical industry. Currently, pyrolysis has been widely applied for OS disposal, while low-oil content (<5 wt%) OS still lacks novel technology to achieve efficient resource utilization and harmful substances immobilization. In this study, a kind of OS-based geopolymer was developed by OS and ground granulated blast furnace slag (GGBS). The results showed that in geopolymer with 30 wt% OS, the content of total petroleum hydrocarbons (TPHs) decreased by 82%, Zn achieved 100% stabilization, and the 28 d compressive strength could still reach 32.8 MPa. The appropriate oil content filled the pores and cracks in geopolymer matrix. The constructed model compounds further elucidated the hydration mechanisms of OS-geopolymer. The nucleation effect of crude oil and micro-aggregate effect of minerals jointly improved the polymerization degree of C-(A)-S-H gels. OS promoted the transformation of [SiO4]4− monomers into C-(A)-S-H unbranched middle groups and three-dimensional networks, thereby efficiently stabilizing harmful substances. Sustainability analysis showed that OS-based geopolymer had good environmental and economic benefits. Overall, this work provides theoretical guidance for the green transformation of OS in the construction field.

Efficient reductive recovery of arsenic from acidic wastewater by a UV/dithionite process

The removal of arsenic (As(III)) from acidic wastewater using neutralization or sulfide precipitation generates substantial arsenic-containing hazardous solid waste, posing significant environmental challenges. This study proposed an advanced ultraviolet (UV)/dithionite reduction method to recover As(III) in the form of valuable elemental arsenic (As(0)) from acidic wastewater, thereby avoiding hazardous waste production. The results showed that more than 99.9 % of As(III) was reduced to As(0) with the residual concentration of arsenic below 25.0 μg L−1 within several minutes when the dithionite/As(III) molar ratio exceeded 1.5:1 and the pH was below 4.0. The content of As(0) in precipitate reached 99.70 wt%, achieving the purity requirements for commercial As(0) products. Mechanistic investigations revealed that SO2·‒ and H· radicals generated by dithionite photolysis under UV irradiation are responsible for reducing As(III) to As(0). Dissolved O2, Fe(III), Fe(II), Mn(II), dissolved organic matter (DOM), and turbidity slightly inhibited As(III) reduction via free radicals scavenging or light blocking effect, whereas other coexisting ions, such as Mg(II), Zn(II), Cd(II), Ni(II), F(−I), and Cl(−I), had limited influence on As(III) reduction. Moreover, the cost of treating real arsenic-containing (250.3 mg L−1) acidic wastewater was estimated to be as low as $0.668 m−3, demonstrating the practical applicability of this method. This work provides a novel method for the reductive recovery of As(III) from acidic wastewater.

AgrI-fiSh: sustainable and innovative feeds from agricultural wastes for a resilient and high-quality aquaculture

The AgrI-fiSh project has been funded under Horizon 2020 - PRIMA, with the research partnership of three Mediterranean countries: Algeria, Italy and Spain. The project will contribute to the transition to a more resilient agro-livelihood system through an innovative and circular farming approach, which promotes an efficient use of biological and natural resources with a valuable increase in productivity. New potential for farms, agri-food systems and local markets will arise from the valorization of agricultural wastes to be used for the creation of high-value plant-based feeds for a sustainable inland aquaculture. Nutraceutical potential of specific agricultural wastes (i.e grape seeds, legumes and cereals), in combination with other components, as Lactic Acid Bacteria (LABs) fermented whey and medicinal herbs, to create plant-based feeds for aquaculture, will foster animal and human health with consequent benefits for the environment, local economies and consumers.

Secondary School Students’ Engagement with Environmental Issues via Teaching Approaches Inspired by Green Chemistry

Green chemistry refers to the design and application of practices that prevent pollution and promote environmental sustainability. A set of 12 principles make up the core of the green chemistry philosophy, and, since their emergence, they have been implemented in the educational practice of tertiary education. Over the past few years, the green chemistry approach has started expanding among secondary education as well. This review discusses green chemistry teaching experiences in secondary education as reported in 70 scientific publications (from 2002 to the present) that were identified via a literature search. All identified documents were examined and analyzed to map their green chemistry content and relevant environmental issues, the degree of the connection between the chemistry concepts and environmental issues (“environmentalization”), the implemented teaching-learning approaches, and, when applicable, the achieved learning outcomes. Analysis showed that all 12 green chemistry principles were covered within the identified publications, with the ones referring to prevention and the use of renewable feedstocks being the most frequent. The publications touch upon several environmental issues, with the most frequent being those referring to hazardous chemical waste, alternative energy resources, and recycling. Most of the publications correspond to a medium degree of environmentalization. The inquiry-based, hands-on-based, problem-based, context-based, and socio-scientific issues-based teaching approaches were shown to be the most widely used. Regarding the achieved learning goals, those mostly explored were related to the cognitive and affective domains. This comprehensive review may provide a solid foundation for the organization and design of novel curricula that will integrate green chemistry into education for sustainable development programs in secondary education.

N, F Co-Doped Carbon Derived from Spent Bleaching Earth Waste as Oxygen Electrocatalyst Support.

Affordable nitrogen and fluorine co-doped carbon nanostructure was prepared from the hazardous industrial waste of edible oil refinery, spent bleaching earth (SBE), and used as raw material for obtaining high-performance non-noble metal bifunctional oxygen electrocatalysts. Waste SBE contains 35 % residue non-saturated oil as a carbon source and the assistance of montmorillonite (MMT) as the template. This study converts waste SBE into a fluorine-doped carbon nanostructure through a pyrolysis process followed by removing the aluminosilicate layers of the MMT by HF etching. Furthermore, the impregnation of the support with Co and Fe nitrates readily gives rise to N, F co-doped carbon (NFC) electrocatalysts, as confirmed by XPS analysis. Electrochemical results evidenced that the Co-NFC catalyst proved to be a valuable bifunctional competitor for oxygen reduction reaction and oxygen evolution reaction in alkaline media, showing activity in both reactions and superior stability compared with the Fe-NFC catalyst in accelerated tests. This work offers a straightforward, economical, and eco-friendly strategy for designing N, F co-doped carbon-based electrocatalysts for oxygen reactions in electrochemical devices.

Feasibility study on using red mud as a viscosity-modifying agent for self-compacting concrete

Red mud (RM) is a hazardous waste material generated during the alkaline leaching of bauxite in the Bayer process. The feasibility of using RM as a viscosity-modifying agent (VMA) for self-compacting concrete (SCC) was proposed in this study. In addition, RM paste, cement paste, RM-blended paste, SCC that containing RM as VMA were prepared, and those fresh properties were investigated with emphasis. The results show that compared to cement paste, the RM paste exhibited excellent water retention. In the RM-blended cement paste with equivalent fluidity, an increase in RM dosage led to a notable decrease in bleeding rate, accompanied by an increase in yield stress and plastic viscosity. Similarly, in the SCC (containing RM as VMA) with equivalent slump-flow, the segregation rate decreased significantly (17.12 % of segregation for SCC that without RM, and 6.88 % of segregation for SCC that with 12 wt% RM), while yield stress and plastic viscosity increased with higher RM dosages, demonstrating a linear relationship. These findings highlight the feasibility of achieving SCC with high slump-flow and non-segregation by using RM as VMA, and the fresh properties of prepared SCC can be effectively controlled. Meanwhile, the findings of this study offer a novel approach to utilize RM and provide valuable guidance for the application of RM used as VMA.

Efficient and selective recovery of Mo and V from spent hydrodesulfurization catalysts via oxidation roasting followed by Na2CO3 and NaOH leaching

Spent hydrodesulfurization (HDS) catalysts containing large amounts of valuable metals, such as Mo and V, are hazardous solid wastes but also valuable secondary resources. However, the current recovery process suffers from the difficulty of balancing the leaching efficiency of Mo and V and their selectivity over Al. This work focused on the effect of phase transformation during roasting operation on the leaching behavior Mo, V, and Al and adopted an oxidation roasting followed by mixed alkali of Na2CO3 and NaOH leaching process to recover Mo and V from spent HDS catalysts. The results indicated that the phase transformation of Mo, V, and Al species during oxidation roasting process played a crucial role in achieving efficient leaching of Mo and V, as well as reducing leaching efficiency of Al. This transformation involved the change in Mo and V species changed from low valent compounds to high valent oxides, and Al2O3 from γ-phase to θ- and α-phases. In addition, efficient and selective leaching of 99.3% Mo and 97.8% V was realized, with only 0.03% Al being dissolved, by roasting the spent catalysts at 700 °C for 2 h and then leaching with a mixed solution of 1.2 mol/L Na2CO3 and 1.6 mol/L NaOH. The efficient and selective leaching of Mo and V can significantly reduce the burden of subsequent separation and purification, which provided an important prerequisite for the development of a new process for the recovery of Mo and V from HDS spent catalysts in alkaline systems.

NH4Cl recovery from high-ammonia organic waste liquor by electrolysis with aluminum soluble anode

High-ammonia organic waste liquor is regarded as highly toxic and non-biodegradable due to containing high concentration of ammonia and organic refractory compounds. Treating high-ammonia organic waste liquor could be costly in the need of large energy or chemical agent input. Recovery of ammonium is an alternative way because high ammonium waste liquor could act as a reservoir of nitrogenous fertilizer. In this study, NH4Cl was separated from waste liquor by electrolysis with aluminum-soluble anode. The white foamy substances with NH4Cl purity over 90 % were produced at a current density of 12.5 mA/cm2 with 100 min electrocution. The white foamy substance production rate was increased as pH rose, and NH4Cl purity increased from 82.44 % at pH 4 to 91.34 % at pH 6. The soluble aluminum from anode sacrifice promoted crystallization and separation of NH4Cl by participating in the formation of CGAs (Colloidal Gas Aphrons) and improving their stability. Organic substances in the liquor functioned as surfactant to generate of CGAs, CGAs carried NH4Cl crystals floated to the surface and formed the white foamy substance. The study proposes an efficient, sustainable method for the hazardous high-ammonia organic waste liquor resource utilization.

Ultrasound-assisted enhanced leaching of lithium and fluoride compounds from waste cathode carbon: Comprehensive recovery and leaching mechanism

Due to the rapid development of the aluminum industry, waste cathode carbon, as a hazardous solid waste, is inevitably generated during the production process of the aluminum electrolysis industry. Improper treatment of waste cathode carbon will inevitably result in significant environmental damage, affecting both flora and fauna. Therefore, ultrasound-assisted leaching was employed to extract the waste cathode carbon, using a sodium hydroxide solution as the leaching medium to recover valuable metals and electrolytes, thereby mitigating environmental risks and reclaiming resources. Optimal conditions for ultrasonic-assisted alkali leaching were determined through a single-factor experiment: a leaching temperature of 70 °C, a liquid-solid ratio of 7:1, a leaching time of 50 min, an alkali concentration of 100 g/L, and ultrasonic power of 250 W. Under these conditions, the fluoride leaching efficiency reached 89.17 %, and the lithium ion leaching efficiency was 86.33 %. Comparative analyses between traditional leaching methods and the optimized experiments revealed that the advantages of ultrasonic action and cyclic leaching contributed to an increase of 5.28 % in the fluoride leaching efficiency and 11 % in the lithium ion leaching efficiency. Furthermore, ultrasonic-assisted leaching significantly reduces the leaching time to 50 min while achieving a higher rate of impurity removal.

Management Of Hazardous And Toxic Waste at PKU Muhammadiyah Hospital Surabaya in 2024

Hospitals, as healthcare service facilities, generate hazardous and toxic waste. Inadequate management can cause health problems both within the hospital environment and in the surrounding community. This study aims to examine the management of hazardous and toxic waste generated by PKU Muhammadiyah Hospital Surabaya.This research uses a descriptive method by collecting primary and secondary data. The subjects in this study are those responsible for the management of hazardous and toxic waste. The data obtained are then analyzed descriptively using the CIPP evaluation method.The context evaluation of hazardous and toxic waste management based on interviews and observations falls into the good category, while the input, process, and product evaluations based on interviews also fall into the good category. However, based on observations, they fall into the sufficient category. This is because several CIPP evaluation variables have not fully met the assessment criteria. It is hoped that the results of this evaluation can be used as feedback to improve the quality of hazardous and toxic waste management at PKU Muhammadiyah Hospital Surabaya.Based on the research results, it can be concluded that the management of hazardous and toxic waste at PKU Muhammadiyah Hospital Surabaya generally complies with Ministry of Health Regulation Number. 2 of 2023. However, its implementation is not yet optimal, as it is adjusted to the hospital's conditions and capabilities. It is recommended that the hospital improve and upgrade the facilities and infrastructure for hazardous and toxic waste management.