Search

Acidophiles are a group of microorganisms that thrive in acidic environments where pH level is far below the neutral value 7.0. They belong to a larger family called extremophiles, which is a group that thrives in various extreme environmental conditions which are normally inhospitable to other organisms. Several human activities such as mining, construction and other industrial processes release highly acidic effluents and wastes into the environment. Those acidic wastes and wastewaters contain different types of pollutants such as heavy metals, radioactive, and organic, whose have adverse effects on human being as well as on other living organisms. To protect the whole ecosystem, those pollutants containing effluents or wastes must be clean properly before releasing into environment. Physicochemical cleanup processes under extremely acidic conditions are not always successful due to high cost and release of toxic byproducts. While in case of biological methods, except acidophiles, no other microorganisms cannot survive in highly acidic conditions. Therefore, acidophiles can be a good choice for remediation of different types of contaminants present in acidic conditions. In this review article, various roles of acidophilic microorganisms responsible for removing heavy metals and radioactive pollutants from acidic environments were discussed. Bioremediation of various acidic organic pollutants by using acidophiles was also studied. Overall, this review could be helpful to extend our knowledge as well as to do further relevant novel studies in the field of acidic pollutants remediation by applying acidophilic microorganisms.

The global COVID-19 epidemic compelled all educational institutions, including universities, to cease academic instruction. To assure the ongoing process of teaching, learning, and assessment, several universities have transitioned from traditional face-to-face techniques to online ones. The purpose of the study was to examine the online-education experience in an Environmental Engineering course using a virtual lab and simulation software, as well as to determine the student's perception of the implementation of virtual labs and simulation software and the benefits of these tools for enhancing learning activities. To familiarize students with various areas of environmental engineering analysis, two simulated experiments were developed: water quality monitoring and adsorption spectroscopy. The virtual labs were generally well-received, as indicated by the responses to the Likert-type questions. Virtual laboratories are more acceptable for senior students than for first-year students, according to the consensus. 88% of respondents agreed with the average of twenty claims, compared with 3% who disagreed and 9% who agreed but disagreed with the statement. This illustrates that, although students believe that substituting virtual laboratories for conventional laboratories is not a complete solution, they believe that virtual laboratories can be used in conjunction with conventional methods to facilitate improved study outside of laboratory hours. Virtual and online learning in engineering labs are still relatively new; additional research is necessary before instructors can effectively utilize this delivery medium and its accompanying technologies to enhance student learning.

Wastewater treatment plants (WWTPs) play the role of intercepting microplastics in the environment and provide a platform for bioremediation to remove microplastics. Despite, this opportunity has not been adequately studied. This paper shows the potential ways microplastics-targeted bioremediation could be incorporated into wastewater treatment through the review of relevant literature on bioaugmentation of water treatment processes for pollutants removal. Having reviewed more than 90 papers in this area, it highlights that bioremediation in WWTPs can be employed through bioaugmentation of secondary biological treatment systems, particularly the aerobic conventional activated sludge, sequencing batch reactor, membrane bioreactor and rotating biological contactor. The efficiency of microplastics removal, however, is influenced by the types and forms of microorganisms used, the polymer types and the incubation time (100% for polycaprolactone with Streptomyces thermoviolaceus and 0.76% for low-density polyethylene with Acinetobacter iwoffii). Bioaugmentation of anaerobic system, though possible, is constrained by comparatively less anaerobic microplastics-degrading microorganisms identified. In tertiary system, bioremediation through biological activated carbon and biological aerated filter can be accomplished and enzymatic membrane reactor can be added to the system for deployment of biocatalysts. During sludge treatment, bioaugmentation and addition of enzymes to composting and anaerobic digestion are potential ways to enhance microplastics breakdown. Limitations of bioremediation in wastewater treatment include longer degradation time of microplastics, incomplete biodegradation, variable efficiency, specific microbial activities and uncertainty in colonization. This paper provides important insight into the practical applications of bioremediation in wastewater treatment for microplastics removal.

Water pollution issues and clean water needs have forced developing countries, such as Malaysia. Relating to clean water demand for covering human activities, water quality index determine several water parameter that presents pollution problem in water. As a water source, clean water in river is a critical concern. River water quality is according to natural process and anthropogenic activities. River water is potential to be contaminated by industrial, domestic and agricultural activities. Thus, in this study, water quality and availability in Manik Urai, Durian and Geh rivers were reviewed. Each pollutants was investigated, for instance BOD, COD, DO, SS, and pH. Range of river water flow was also examined. Total water demand was mentioned. In addition, the impacts of drought in 1990-2016 were assessed. However, review resulted that climate change has severe impact in water supply system.

Proactive strategies are being opted by metallurgical, foundry and manufacturing industries with respect to their experiences working with product designing based on product life cycle assessments. Without the consideration of the potential impacts on the life cycle, the development of new products would barely be sustainable. “Green” composites or bio-composites are fully degradable composites mainly consisting of a blend of biopolymer matrix and natural fibers which act as a reinforcing phase. In this study, natural bio-composite was reviewed as an alternative sustainable product. The types of natural fibers were also described as raw material of natural bio-composite. In addition, development natural fibers nowadays were mentioned. Furthermore, the application of natural fiber reinforced bio-composites was also presented.

Over the past decade, nanotechnology has been developed and employed across various entities. Among the numerous nanostructured material types, enzyme-incorporated nanomaterials have shown great potential in various fields, as an alternative to biologically derived as well as synthetically developed hybrid structures. The mechanism of incorporating enzyme onto a nanostructure depends on several factors including the method of immobilization, type of nanomaterial, as well as operational and environmental conditions. The prospects of enzyme-incorporated nanomaterials have shown promising results across various applications, such as biocatalysts, biosensors, drug therapy, and wastewater treatment. This is due to their excellent ability to exhibit chemical and physical properties such as high surface-to-volume ratio, recovery and/or reusability rates, sensitivity, response scale, and stable catalytic activity across wide operating conditions. In this review, the evolution of enzyme-incorporated nanomaterials along with their impact on our society due to its state-of-the-art properties, and its significance across different industrial applications are discussed. In addition, the weakness and future prospects of enzyme-incorporated nanomaterials were also discussed to guide scientists for futuristic research and development in this field.

An essay was used as an assessment to illustrate a certain way of thinking and attitude of a student. The essay demonstrates the student's utmost degree as an author with a cognitive and affective style. The study aimed to provide a simple description of the essay as an assessment and critical function in the Groundwater Contamination course of the Environmental Engineering Program offered by Curtin University Malaysia. Groundwater Contamination is designed for students of environmental engineering and covers a number of topics, including groundwater characterization, contaminant transport processes in groundwater flow systems, migration and chemical development of contamination plumes, and groundwater remediation. No correlation exists between essay length (word count) and report or presentation grades, while there was a strong relationship between the student mark and essay content (R2 = 0.88), but a moderate relationship to essay format (R2 = 0.55). Overall, the students at Curtin University Malaysia were able to meet the Course Outcome of Groundwater Contamination and the Program Outcome of Environmental Engineering because of the essay they wrote as a test.

Government plays the most important role in improving the waste management system. Incineration system can be introduced into the waste management system to incinerate specific type of waste. This will increase the availability space for the landfilling process. However, the incineration process must be carried out with full pollution control system to prevent and minimize the pollution that might cause during the incineration process. Other than that, the government should encourage the public to separate out the waste into different categories before the collection of the waste by the waste management company. This can be implemented by providing guideline for the separation of waste methods as well as encouraging the public to be responsible for own produced waste. The dumpsites must also be improved and it is suggested that all dumpsites used are engineered sanitary landfill. An engineered sanitary landfill will reduce the impact of the pollution towards the environment to the minimum. Better tools also must be included in the sanitary landfill system to monitor the condition of the landfill site. This will prevent the happen of any unexpected conditions and can be resolve before the happening of the unexpected condition. Last but not least, the government should implement new charging fee system for the waste management. The charging fee should be based on the rate of waste generated but not flat pricing. This will help in reducing the waste generated as all individuals must pay for their own generated waste. The earth belongs to everyone which indicates everyone have the responsible to keep the earth clean and to reduce the waste produce.

In recent years, one of the primary issues noted worldwide in the environment is the contamination of crude oil in soil. In comparison to traditional methods, bioremediation offers a potential alternative for removing hydrocarbon pollution from the environment. This review paper gives an overview of the benefits, mechanism, and operation of aerobic composting remediation of soil contaminated with crude oil. Within this study, it was demonstrated that with composting technology, one could successfully treat crude oil contaminated soil with a > 90% removal efficiency. Aerobic composting utilizes aerobic bacteria and fungi that require oxygen to grow and biodegrade crude oil’s biological component into carbon dioxide and water, whereas anaerobic composting utilizes anaerobic microbes that grow in the absence of oxygen and convert the crude oil’s organic component primarily into methane. In terms of efficiency, biodegradation capacity, and rate, aerobic conditions outperform anaerobic conditions. Numerous parameters have been discussed and demonstrated to have an effect on the composting condition and also on the bacteria and fungi used to biodegrade crude oil contaminants at various stages of the composting process, including initial concentration, soil type, soil/compost ratio, aeration rate, moisture content, C/N ratio, pH, and temperature. Microbes use crude oil organic matter as carbon and energy sources during the composting process, whereas fungi produce enzymes that catalyze crude oil oxidation reactions. It is believed that the mutualistic and competitive interactions between bacteria and fungi maintain a robust biodegradation system. The thermophilic phase exhibited the highest rate of biodegradation. However, the presence of a diverse and dynamic microbial community throughout the composting process ensures that crude oil degradation occurs. The efficient composting processes using specific microbes need to be investigated.

Pyrene is a very resistant polycyclic aromatic hydrocarbon (PAH) with four benzene rings that survives in the environment. This study was aimed at investigating the tolerance of earthworms in soil contaminated with pyrene. The studies were performed by employing earthworms gathered from shady regions adjacent to sewage ponds as pyrene degraders to eradicate pyrene from the soil. Numerous factors affecting pyrene degradation efficiency were explored, including the effects of contaminant concentration, earthworm and soil ration, and soil condition. The highest pyrene removal (31.2%) was shown by earthworms in the condition of soil mixed with cow dung. Pyrene decomposition was inhibited during soil sterilization due to the absence of soil microorganisms and indigenous pyrene-degrading bacteria. Nonetheless, earthworms are suitable for use as pyrene degraders in contaminated soil.

The utilization of less expensive and more effective adsorbents derived from a variety of basic materials has been investigated. The research aimed to investigate the feasibility of employing waste paper as the adsorbent to remove the cresol red (CR) dye from wastewater through adsorption mechanism. Langmuir, Jovanovic, and Freundlich model were observed for isotherms models, while pseudo-first-order and pseudo-second-order were examined for kinetic models. The results indicated that increasing the adsorbent dose and contact time gave no significant effect to adsorption capacity while adsorption capacity increased with the increasing of pH until it reached a maximum at pH 8, and raising the starting dye concentration leads in a significant increase in adsorption capacity (16.7 mg/g). When the experimental adsorption isotherms and kinetic were fitted using the Freundlich models and pseudo-second-order model, it was discovered that those models were more accurately represented by the data, as indicated by a high correlation coefficient (R2) of 0.974 and 0.963.

Seagrass meadows provide important ecological functions, particularly by serving as carbon sinks and breeding grounds for marine species. Climate change has threatened seagrass communities, causing their replacement, loss and increased vulnerability. This review examined scholarly articles published between 2010-2021 to comprehensively present the impacts of climate change on seagrass meadows. It shows that ocean warming negatively affects seagrass communities by favouring communities of lower structuring capacities, thus reducing the effectiveness of their ecological functions. Ocean warming also promotes the propagation and spread of invasive species, and changes the trophic structures leading to further loss of seagrasses of value. Higher seawater temperature is associated with shoot mortality and retarded growth of certain seagrasses. Sea level rise causes more wave energy to be received by coastal seagrass communities, thus, creating more damage to the communities. Deepening sea limits light penetration and alters distribution of seagrass meadows. Carbon dioxide enrichment of seawater increases photosynthetic rate of seagrasses but ocean warming and acidification counteract this beneficial effect. Carbon dioxide enrichment affects different seagrass species and different parts of a seagrass species differently, and, where beneficial to seagrass communities, could enhance their ecological services. Temperature extremes could kill seagrasses while marine heatwaves and flooding could act synergistically to increase carbon demand of certain seagrasses and unfavourably change their biomass. These impacts are often aggravated by anthropogenic activities. This review calls for more studies and conservation efforts to understand the impacts of climate change on seagrass communities and future-proof them against the changing climate.

The adulteration of the environment by hazardous waste, such as heavy metals, nuclear wastes, hydrocarbons, pesticides and greenhouse gases is the major serious problem which need to be reduced. Common remediation technique such as physical, chemical and biological process are being applied. Chemical process can transform and change organic contaminant of interest which is not sufficient to clean the environment, while physical technique requires additional equipment. Thus, bioremediation exist as green approach to eliminate the hazardous waste in the environment. In this review, bioremediation is comprehensively presented. Remediation process types, challenges, limitations, mechanisms, and future suggestion has been elaborated to develop bioremediation technology for future prospect.

The issues of global warming and greenhouse gasses have raised the concern of the people and led to integrate ambitious of using bioenergy in many countries. In this paper, the issues of conventional energy are stated, and the different types of conventional energy resources are discussed including coal, petroleum and natural gas. The process of pulverized coal combustion (PCC) to generate electricity is also studied and discussed in this paper to have a better understanding of the process and the emission of greenhouse gas released from the use of coal to generate conventional energy. The reason of soil contamination and air pollution caused by the refinery process of petroleum is also discussed in this paper and several study cases of the social economic impact caused by the production of natural gas in development countries. Furthermore, the used of bioenergy and different type of bioenergy resource are discussed including biogas, algae biofuel, and biodiesel. The process of algae cultivation for algae biofuel and the study of toxic waste algae strains that can give a negative impact to the environment is studied to avoid harmful substances released to the environment. The potential algae application in different fields is also included to show the benefit of algae biofuel which is flexible and able to contribute to the global economic growth. Lastly, the advantages of using bioenergy are discussed including the mitigation of greenhouse gas emission, improve social economic growth, renewable energy resources and prevent prescribed burning of the forest.

There are several environmental issues caused by economic growth and urbanization, such as soil degradation, water scarcity, deforestation, and biodiversity extinction. To solve these environmental problem issues, cleaner production (CP) had presented as account to reduce waste generation, energy usage and environmental pollution.CP concept was accepted and applied on many industrial sectors. Based on the current trend, CP is shifting to tackle global environmental problems by focusing on reducing carbon emission and resources consumption. In this paper, implementation of CP was presented such as waste and pollutants reduction, process and products efficiency improvements, and risk reduction towards human and environment. Overall, CP is an effective tool not only in environmental protection, but also in company management as it can increase the profit gains, reduce resources consumption, reduce pollutants emission and protects the safety of staff and workers.

The ASEAN population will increase to 724.8 million by the year 2030 and the urbanization rate increases with years. This leads to the development of the construction industry to fulfil the fundamental social and physical requirements. Construction activities create an adverse negative impact on the environment, such as pollution and damage to the environment. This article will study more about the construction and demolition waste (C&D waste) and it can be founded in various construction stages. Therefore, the government and authorities introduce environmental management practices to mitigate the negative impact on construction on the environment and minimize the pollution at the source. What, why and where are terms required to consider before the implementation of environmental management practice. The government policies of Malaysia, Singapore and Thailand are summarized. Approximately 10% of total synthetic carbon dioxide (CO2) sourced from concrete production. The content more emphasizes the green materials generated from agricultural waste to replace the silica in concrete. The bamboo is used as interior decoration and material for building construction. Green materials technology is solar panel, solar thermal collector, geothermal technology, hydropower technology and cooling roof system.

With the growth of urbanization, the anthropogenic activities have increased and thus increase occurrence of soil contaminants. In order to eliminate the contaminants in soil environment, the application of nanotechnology for soil remediation has become a great concern in the world. This review will discuss about the fate of contaminants in soil environment; the mechanisms of nanotechnology with various types of nanomaterials for the soil remediation; the advantages and disadvantage of nanomaterials towards the terrestrial organisms, human health as well as the soil environment; and the challenges of using nanotechnology for soil remediation.

Heavy metal (loids) in wastewater persists as a contagious and non-biodegradable environmental pollutant. With the ever rising of nanotechnologies in various field, there is a mass flux of heavy metal (loid)s being transmitted in many water sediments includes wastewater and rivers in which difficult to eliminate through conventional treatment processes. The introduction and development of nanomaterials have been increasingly utilized. Their high absorption capacity and unique properties in eliminating heavy metal pollutants and other nano pollutants have been extensively used in the remediation of inorganic pollutants. This review study illustrates the different types of nanomaterials that are utilized in various treatment process such as nano zero-valent iron (nZVI), carbon nanotubes and titanium dioxide nanoparticles (TiO2NPs). The mechanism of each nanomaterial and also its advantages and disadvantages are being portrayed. The identified factors affecting their efficiency in eliminating heavy metal and other inorganic pollutants are briefly described.

China has one of the world’s fastest-growing economies due to its increase in various industrial activities. A side effect of economic growth is severe environmental problems such as heavy metal contamination of soil and groundwater. Anthropogenic activities are the main sources of cadmium which is highly mobile and toxic with the potential to bioaccumulate in the ecosystem. It can contaminate ground and river water consequently negatively impacting agriculture and water sources. Anthropogenic source of Cd concentrations in China is 0.002 mg/L in drinking water, 0.102 mg/kg in soil, and 0.23–0.96 mg/kg in paddy soil. Geological trends and health implications of cadmium contamination in Human, southern China were analyzed. Source, transportation, and various conventional remediation processes exist today and can be categorized as biological, physical, and chemical. Using nanoparticle technology, it has been found that adsorption capacities can be 3 to 4 times higher compared to using powdered activated carbon. From the experiment carried out, a maximum adsorption capacity of 10.86 mg/g for cadmium was obtained. Cadmium intake in south China populations occurred at an alarming rate and most children were at greater risk of being affected. Therefore, cadmium contamination should be taken seriously by the responsible authorities.

The introduction of plastic sectors has resulted in the presence of microplastics (MPs) in water systems, which has become a global issue that has attracted scientific and community awareness. MPs can be detected in a variety of sources such as beauty products, manufacturing effluent, or fishing activities. This study examined the repercussions posed by MPs' prevalence on land and marine environments and human health issues. Henceforth, remediation technologies must be introduced to shift out MPs from the water supplies in order to sustain the environmental quality for future generations, the benefits and drawbacks of the technology applied. This study also portrays difficulties encountered in MP research as the hurdles must be mastered in order to properly comprehend the MPs. The cooperation between nations is the most critical aspect in fully tackling MP issues as it can be easily carried by wind or water and its damage can be larger than predicted.