Showing papers in "Environmental Technology and Innovation in 2019"

Bioremediation of heavy metals by microbial process

Abstract: Bioremediation is an inventive and optimistic technology which is applicable for the retrieval and reduction of heavy metals in water and polluted lands. Microorganism plays an essential part in bioremediation of heavy metals. By using genetic engineering, genetically modified organisms can be generated which can likely reduce different types of polycyclichydrocarbons (PAHs). Flavobacterium, Pseudomonas, Bacillus, Arthrobacter, Corynebacterium, Methosinus, Rhodococcus, Mycobacterium, Stereum hirsutum, Nocardia, Methanogens, Aspergilus niger, Pleurotus ostreatus, Rhizopus arrhizus, Azotobacter, Alcaligenes, Phormidium valderium, Ganoderma applantus are some microbial species that help in bioremediation of heavy metals. This review not only discussed about the importance of microbes for bioremediation of heavy metals but also discussed about the challenges and limitations of native and engineered bacteria for bioremediation. Significance of bioremediation with the help of genetically engineered bacteria is in light because of its eco-friendly nature and minimum health hazards other than the physio-chemical dependent strategies, which are less eco friendly and dangerous to life.

Removal of toxic pollutants from water environment by phytoremediation: A survey on application and future prospects

Abstract: Pollutants is one of the ecological contaminations for the time being days as effect of mechanical improvement in a few nations. Heavy metals and dyes give harmful consequences for human wellbeing and cause a few genuine maladies. A few systems have been utilizing for expelling toxic contaminants from the natural yet these strategies have impediments, for example, cost expense, logistical issues and time consuming, low efficiency. Phytoremediation is the best alternative for tidying up condition, as it is the naturally economical and ecologically practical innovation. Phytoremediation offers proprietors and chiefs of toxic polluted locales is an imaginative and financially effective choice to address headstrong natural contaminants. As it uses plants characteristic capacity to suck the contamination present in the dirt. There are numerous plants having this regular capacity to up take the toxic contaminants and natural contaminations from air, soil and water. There are distinctive subsets of phytoremediation; the most successfully utilized ones are (a) Phytostabilization (b) Rhizodegradation (c) Rhizofiltration (d) Phytodegradation (e) Phytoextraction (f) Phytoaccumulation (g) Phytovolatilization. This review focuses on fortifying innovation system, upgrade the resilience and protection from toxic contaminants, and application impact of phytoremediation.

Treatment technologies of palm oil mill effluent (POME) and olive mill wastewater (OMW): A brief review

Abstract: Attributable to the enormous population growth, tonnes of effluents are unavoidably generated throughout the agricultural activities. The inadequate effluents disposal induces perpetual contamination to the sea and river water sources, which has subsequently raised the public environmental concern. For that reason, the handling protocol of agricultural effluents was flagged up as an interest area for research. Despite the environmental hazards, agricultural effluents have the potential to be transformed from wastes into wealth via biological, physicochemical, thermochemical or a combination of processes thereof. The identical characteristics of palm oil mill effluent (POME) and olive mill wastewater (OMW) render the possibility of treating these wastes using the similar treatment method. Generally, biological treatment requires a longer process time compared to physicochemical and thermochemical technologies despite its easy and low-cost operation. Comparatively, physicochemical and thermochemical methods extend their potentiality in converting the agricultural effluents into higher value products more efficiently. This paper reviews the source and characteristics of both POME and OMW. Subsequently, a comparison of the current and alternative treatments for both effluents was done before the future perspectives of both effluents’ treatment are paved based on the well-being of the human, environment, and economic.

Plastics and microplastics: A threat to environment

Abstract: Plastics are synthetic polymer compound mostly made from petrochemical sources, such compound has high molecular mass and plasticity and certain chemicals are added to increase the performance and efficiency of the products. Plastics size less than 5 mm are categorized as Microplastics and it is one of the greatest potential threat to marine environment for the whole world. There are two types of micro-plastics i.e. primary micro-plastics and secondary micro-plastics. Primary microplastics are the by-products of particulate emissions released from industrial production, the release of plastics dust from plastics products. Secondary microplastics are larger plastic particulate material. These micro-plastics eventually end up in water bodies travelling all the way from rivers to seas or oceans. Microplastic can also act as a pollutant transport medium for other toxic elements such as DDT and hexachlorobenzene and eventually end up within the body of a living organism who consume it. The Government Agencies and Non-government organization of different nations have adopted many policies and laws to curb the harmful effects of plastics and microplastics. A concrete and comprehensive plan should be adopted for zero tolerance against plastics waste and peoples participation is a must to achieve the full success.

Perspectives on arsenic toxicity, carcinogenicity and its systemic remediation strategies

Abstract: Bioaccumulation of heavy metal in biological systems is an important cause of concern for environmental health and safety. Arsenic is one of the most hazardous metalloid, deserves special attention on account of its toxicity and carcinogenicity in the environment. The present paper reviews the current knowledge about the toxicity, carcinogenicity, and remediation strategies for arsenic removal from the environmental systems. The toxicity of arsenic depends mainly upon its speciation. Exposures of arsenic in drinking water lead to the cancer of skin, lungs, and bladder. The paper gives an insight into the arsenic removal by physicochemical processes, and the feasibility of using biological methods, the use of bacteria, and algae, its potential for sustainable use and environmental compatibility. The ability of the microbes to remove the metalloid via the process of mobilization and sorption of arsenic through the oxidation, reduction, methylation, and co-precipitation has been discussed in this paper. Lastly, the use of in silico approach to study the remediation of arsenic with the aid of systemic strategies, genomics, and molecular docking.

Technology alternatives for decontamination of arsenic-rich groundwater - a critical review.

Abstract: Arsenic (As) contamination of groundwater is being reckoned as a global problem, as over 296 million people residing in more than 100 countries have already been reported to be affected by arsenic-rich groundwater. Developing countries like Bangladesh, India, Thailand, Taiwan and Vietnam are the worst victims of this terrible event. Arsenic naturally exists in more than 320 mineral forms mainly as arsenates, sulfides, sulfo-salts, arsenides, arsenites, oxides, silicates and elemental arsenic. The lifetime cancer risk of arsenic at its Maximum Contaminant Level (MCL of 10 μ g/L) is estimated at 0.7 in 100, while for other carcinogens, it ranges from ( ∼ 0.001 to 0.012) in 100. Water, besides food, is the main source of arsenic ingress into the human system. Both groundwater and surface water are being found contaminated with arsenic due to natural and anthropogenic activities respectively Over the years, various physico-chemical and biological methods viz. oxidation, coagulation–flocculation, adsorption, biological sorption, ion-exchange, membrane processes, treatment with bio-organism and electrocoagulation have been profusely experimented and reported by different researchers for arsenic remediation from the groundwater. In this paper, various technologies available for arsenic remediation, their removal mechanisms, cost-effectiveness and sustainability have been reviewed in a critical and rigorous manner. Attempts have also been made to point out the advantages and drawbacks of different methodologies and future research needs in the sphere of arsenic remediation from groundwater.

Mechanothermal and chemical recycling methodologies for the Fibre Reinforced Plastic (FRP)

Abstract: Materials have become an integral part of our lives owing to their wide usability, but at the same time, they are affecting the nature antithetically. Fibre Reinforced Plastic (FRP) is highly sought materials in an automobile, aerospace, structural, transportation and other industries due to its excellent mechanical performance, durability, and lightweight. Currently, miscellaneous industries manufacture engineered composite products using FRP materials, especially the products of hardbound thermoset resins, which are difficult to reprocess or reuse. Landfills and incineration are the most common technique for discarding the non-degradable FRP waste that has created an inimical impact on the environment and ecosystem. In order to reduce the ecological burden, we need to evaluate economical and feasible FRP recycling techniques. Extensive investigations conducted over the past decades have proven their efficacy in substituting the currently existing recycling processes. This review article enumerates the mechanical, thermal (fluidised bed and pyrolysis), chemical (low temperature and supercritical temperature) recycling methodologies, and their efficiency in degrading copious FRP materials like glass, carbon, natural etc. In addition, the economic and environmental aspects of fibre reinforced plastic materials based on life cycle assessment (LCA) has been discussed.

Biomineralization based remediation of cadmium and nickel contaminated wastewater by ureolytic bacteria isolated from barn horses soil

Abstract: Environmental contamination by toxic heavy metals such as cadmium and nickel is a serious problem. Metal carbonate precipitation has been suggested based on urea decomposition for use in wastewater and soil remediation applications. Therefore, Cd(II) and Ni(II) removal was examined from an environmental viewpoint. In this work, biomineralization of cadmium and nickel in aqueous solutions by six urease-producing bacterial strains isolated from barn horse’s soil samples has been investigated based on microbially induced precipitation (MIP). The enzyme urease produced by these bacteria can hydrolyze urea to carbonate ions leads to increase pH of the wastewater which results in mineralization of the heavy metal ions and their final conversion to metal carbonates precipitates. Only two bacterial strains have been adopted depending on their ability to tolerate high concentrations of toxic metal ions. Bioprecipitation of Cd(II) and Ni(II) was assessed by consideration some factors that affecting on metal bioprecipitation process. These factors include metal toxicity to the bacteria (in term of initial metal concentration) and treatment time. The bioprecipitates were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The selected bacterial isolates demonstrated high endurance with toxic heavy metals and therefore, high Cd(II) and Ni(II) removal rates, ranging from 96% for cadmium to 89% for nickel following incubation for 48 h and at 500 mg/L initial concentration of each Cd(II) and Ni(II). Furthermore, coprecipitation of Cd(II) and Ni(II) with calcite precipitation has been also performed and the results demonstrated that this technique can be beneficial for Cd(II) and Ni(II) biosequestration.

Urban heat island, urban climate maps and urban development policies and action plans

Abstract: This paper aims at drawing attention to the deficiencies of urban heat island (UHI) mitigation strategies and urban climate maps (UCMs) towards practical implementations and efficient interventions in urban development policies and action plans (UDP/AP). The paper critically reviews the knowledge of the UHI and UCMs to identify the major shortcomings in the production of action plans. The shortcomings are identified in three aspects including (1) active involvement in UDP/AP (2) urban managerial and governmental actions, and (3) public engagement and participation. More specifically, it is first discussed that the current synthesizing paradigm of UCMs and UHI studies only considers the physical aspects of the problem/solution. Second, climate recommendations have paid a little attention to the imperative role, capacities and motivations of urban governance and managerial organizations. Third, mitigation strategies have been proposed without considering public needs and willingness. To overcome these challenges, a collaborative platform of UCM systems should be developed through a holistic approach. Such platform should provide a ground for efficient interventions in UDP/AP as well as interactions of all actors and indicators. To this end, the technical challenges of the UHI studies and UCM systems to link with UDP/AP are discussed. Second, UCMs should explicitly define the role of urban climate governance, prioritize the actions and state the policy agendas with regard to local government capacities and motivational elements. Finally, local communities’ needs’ and stockholders’ opinions should be involved in the synthesizing process. As a potential solution, need-base approaches and weighing systems should be further developed to consider all urban actors’ perspectives.

Optimizing textile dye removal by activated carbon prepared from olive stones

Abstract: Activated carbon prepared from black and green olive stones were successfully used as an adsorbing agent to remove methylene blue from water. Scanning electron microscopy showed how the deep abundant cavities were occupied after adsorption. Fourier-transform infrared spectroscopy showed various functional groups on both adsorbents before and after adsorption. It was also noted that the highest N%, H% and C% prior to adsorption was found in black activated carbon olive stones. Furthermore, results showed that the maximum adsorption of methylene blue was at the optimum pH value of 10. The maximum adsorption capacity of methylene blue was 714 and 769 mg/g for black and green activated carbon olive stones, respectively. Methylene blue removal efficiency reached its maximum capacity at approximately 79%. The equilibrium data were best fitted by Freundlich isotherm reaching R2 value of 98%. In addition, thermodynamic studies resulted in negative Δ G ∘ value indicating that the adsorption process was spontaneous and feasible, negative Δ H ∘ value confirming the exothermic reaction of the adsorption process, and positive Δ S ∘ value for green activated carbon olive stones was higher than that for black activated carbon olive stones indicating the good affinity of methylene blue towards the adsorbent.

Mechanistic understanding and future prospect of microbe-enhanced phytoremediation of polycyclic aromatic hydrocarbons in soil

Abstract: Restoring polluted land is a time-consuming endeavor due to the difficulty inherent in the process. The quality of soil considerably worsens with the addition of toxic persistent organic pollutants (POPs) of industrial origin. Industrialization results in millions of tonnes of POPs worldwide, which pose a threat to surrounding ecosystems. In India alone, oil refineries generate approximately 28,000 tonnes of oily sludge (toxic organic compounds) per annum containing POPs—polycyclic aromatic hydrocarbons (PAHs). These PAHs have existed in environments throughout the globe for the last several decades due to long half-lives. The fate of PAHs and their residues pose a threat to all forms of life. High levels of the 16 PAHs (US EPA) were found in soil in Asia’s oldest oil and gas drilling site, with a range spanning from a minimum of 13.48 to a maximum of 86.3 mgkg − 1 due to exploration of crude oil. The management of such a paradoxical situation is a challenge. The mitigation of PAHs by employing plant–microbe systems from soil is a low-cost prospective biotechnological approach. This technology engineers the rhizosphere and helps restoration of degraded land. Recent findings demonstrated how adding biochar (carbon rich phytoproduct) to the soil resulted in positive effects on plant–microbe assisted PAH removal. This review focuses on the mechanistic understanding of plant–microbe assisted remediation. We consider the future prospect to optimize the phytoremediation process through genomics and metabolomics data. The genetic manipulation of plants and microbes seems to have improved the phytoremediation process by utilizing the signaling network of plant–microbe interactions

Heavy metals/metalloids remediation from wastewater using free floating macrophytes of a natural wetland

Abstract: Potential bio-agents in context of phyto-technological innovation for removal of heavy metals/metalloids have been tightly linked with amelioration of environmental and human health. The present research investigated the prospective of three wetland plants Pistia stratiotes (water lettuce) Spirodela polyrhiza (a duckweed), and Eichhornia crassipes (water hyacinth) for synchronized multi-metallic removal of six hazardous/non-essential metals (Fe, Cu, Cd, Cr, Zn, Ni) and As (a metalloid) from a Ramsar site of a biodiversity hotspot. Results revealed high removal (>79%) of different metals during 15 days experiment in microcosms. Further, a saturation limit was reached in relation to heavy metals/metalloid removal, and thus it declined after two weeks of phytoremediation experiment in case of water lettuce and water hyacinth (about 8 days saturation limit noticed for duckweed). In the context of phyto-technological efficiency of selected wetland plants, E. crassipes was the most efficient for the removal of selected heavy metals followed by P. stratiotes and S. polyrhiza Significant correlations between metal concentration in remediated water and wetland plants/macrophytes were obtained. Therefore, these wetland plants may be used in devising eco-friendly remediation of hazardous heavy metals from wastewater.

Evaluation of Cd(II) biosorption in aqueous solution by using lyophilized biomass of novel bacterial strain Bacillus badius AK: Biosorption kinetics, thermodynamics and mechanism

Abstract: The accumulation of heavy metals in different components of the environment as a result of the anthropogenic interventions raises serious concerns due to their toxic behavior towards the humans and other forms of life. Dried bacterial biomass of Bacillus badius AK was characterized for its potential application in biosorption of Cd(II) in a batch system. The optimum conditions of biosorption were determined to be pH at 7, contact time of 30 min, initial biomass dosage of 2 g/L at a constant temperature of 40 °C, the initial metal concentration of 100 mg/L and agitation at 150 rpm. The maximum biosorption capacity of Cd(II) on Bacillus badius AK was 131.58 mg/g. Kinetics study revealed that the pseudo-second order model fitted better than the first order model. Langmuir isotherm fitting depicted the monolayer adsorption behavior. The results indicated that the bacterium Bacillus badius AK was effective in the removal of Cd(II), which provides important perspectives on its usage in the treatment of the contaminated wastewater on a large-scale.

Constructed wetland modified by biochar/zeolite addition for enhanced wastewater treatment

Abstract: Wastewater treatment for water reuse has received considerable attention owing to water resource shortage. One of the most effective wastewater treatment methods involves the use of constructed wetlands (CWs). In this study, synthetic wastewater was treated by using a biochar/zeolite CW. Phragmites australis (common reed) was translocated into two cylinders (lysimeters) that serve as vertical subsurface flow CWs. One CW (CW1) contained gravels as substrate layer, whereas the other CW (CW2) contained three substrate layers, namely, biochar, zeolite, and gravel layers. Response surface methodology was used for statistical analysis. In this study, CW2 performed better in removing pollutants from wastewater than CW1. At optimum pH (6.3) and retention time (57.4 h), 99.9% (1000 mg/L) COD, 99.9% (1000 mg/L) ammonia, 99.9% (50 mg/L) phenols, 99.9% (50 mg/L) Pb, and 99.9% (50 mg/L) Mn were removed by CW2. During this research, nitrous oxide emission was lower in CW2 than in CW1.

Enhancing adsorption of malachite green dye using base-modified Artocarpus odoratissimus leaves as adsorbents

Abstract: As an extension to successful adsorption of malachite green dye onto Artocarpus odoratissimus (Tarap) leaves, the surface of the leaves was modified by using a strong base, namely sodium hydroxide (NaOH). The isotherm was best fitted to the Redlich–Peterson model. Based on monolayer adsorption using Langmuir model, the q m a x value of Tarap leaves enhanced from 254.9 to 422.0 mg/g upon the modification, and increased by 3 fold when using the Sips model. This paper provided a better insight on the types of reactions that occurred during the adsorption process and the strength of attractions between adsorbent–adsorbate supported with the aid of multiple characterization methods. Other influencing parameters on adsorption such as contact time, ionic strength, pH, temperature and initial dye concentrations were also studied.

Phytotoxicity of nano-zinc oxide to tomato plant (Solanum lycopersicum L.): Zn uptake, stress enzymes response and influence on non-enzymatic antioxidants in fruits

Abstract: The production of metallic nanoparticles is greatly increasing due to its wide range of applications in agricultural formulations. The present pot experiment investigated the uptake of Zn from nano-zinc oxide (n-ZnO)-amended soil at 300, 600 and 1000 mg n-ZnO/kg concentrations, and its effects on the enzymatic and non-enzymatic antioxidants in tomato tissues and fruits respectively. Results showed that root uptake of Zn increased with increasing n-ZnO concentrations. The enzyme activity showed that n-ZnO, through the generation of H 2 O2 and induction of oxidative stress, significantly reduced the activity of stress-controlling enzymes (APX and SOD) in the root. Conversely in leaves, despite alteration in chlorophylls in the early growing stage, APX activity was only significant at 1000 mg n-ZnO/kg) while SOD activity was enhanced at all treatments. CAT activity was significantly reduced, unlike in the roots where CAT activity was significantly enhanced. Contents of total phenols, flavonoids, β -carotene and lycopene in fruits were significantly reduced by at least 4.8% while ascorbic acid was promoted at low n-ZnO treatments. In conclusion, the toxic effect of n-ZnO on stress enzymes was prominent in tomato roots, and there was also inhibitory effect on induction of non-enzymatic antioxidants in the tomato fruits.

Zeolite coated urea fertilizer using different binders: Fabrication, material properties and nitrogen release studies

Abstract: Zeolite is the most widely used coating material in developing controlled release fertilizers (CRF) due to low cost and its inherent cation exchange property that effectively controls the nutrient release rate. Using an appropriate binder is the key in fabricating structurally stable zeolite based CRF due to the poor binding behavior of zeolite. In this research, five different binders, namely corn starch, potato starch, bentonite clay, white cement, and acrylic polymer were used in fabricating zeolite coated urea CRF using a pan granulator at different operational conditions. The fabricated CRFs (using five different binders) were characterized by particle size distribution (PSD), structural stability, crushing strength, elemental analysis, Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Nitrogen release rate from the CRFs was investigated by laboratory studies. The zeolite coated urea with acrylic polymer binder (UZ-AP) was found to be structurally stable with high crushing strength. The SEM analysis revealed that UZ-AP had dense coating and tiny pores with 135- 150 μ m coating thickness. The FT-IR analysis predicted the hydrophilic nature of the CRF. The UZ-AP controlled the nitrogen release by 54.7% compared to other CRFs. Thirty days soil column study for UZ-AP and urea concluded that leaching of nitrogen decreased by 65% compared to urea fertilizer. This newly developed zeolite coated urea could be a potential nitrogen fertilizer with controlled release property for efficient crop nitrogen management.

Seasonal variation of plastic debris accumulation in the estuary of Wonorejo River, Surabaya, Indonesia

Abstract: Plastic has emerged as a common pollutant in marine environments. The majority of the plastic debris in oceans originate from river streams. Some of these debris will end up being accumulated in estuaries. This study aimed to investigate the seasonal variation of plastic debris accumulation in the estuary of Wonorejo River in Surabaya, Indonesia. This research focused on the amount of visible plastic debris (VPD) accumulated along the seashore of Madura Strait during the dry and rainy seasons. Three representative sampling points (SPs) were chosen in the Wonorejo River Estuary area. Data normality was tested using the Kolmogorov–Smirnov test and resulted in normally distributed data. One-way ANOVA was used to determine the correlation between seasonal variation and the accumulation of VPD in all SPs. Tukey’s honest significance test was used to further analyze the significance of the accumulated VPD in each season. Result showed that the accumulation of VPD was significantly higher during the rainy season compared to dry season (p

Core–shell magnetic nanocomposite of Fe3O4@SiO2@NH2 as an efficient and highly recyclable adsorbent of methyl red dye from aqueous environments

Abstract: The core–shell magnetic nanocomposite of Fe3O4@SiO2 was synthesized by silica source that extracted from rice husk. Afterward, functionalized by 3-aminopropyltrimethoxysilane (APTMS) via post-synthesis grafting for selectivity improvement of methyl red (MR) adsorption. The magnetic property, chemical structure and morphology of the synthesized sorbent (Fe3O4@SiO2@NH2) were characterized by XRD, zeta potential, VSM, FT-IR, SEM, EDX and TEM analyses, respectively. Adsorption of MR onto the sorbent was investigated with designing 20 series of experiments by the CCD under RSM. The interaction between three separate variables including initial pH of solution, initial concentration of MR and dosage of sorbent were considered for obtain R (removal efficiency) and q e (adsorption capacity) as the responses. The optimum pH, MR concentration and sorbent dosage found 5.24, 100 mg L − 1 and 0.5 g L − 1 , respectively, were given maximum R of 51.64% and a maximum q e of 81.39 mg g − 1 with desirability of 0.826. Adsorption kinetic and isotherm studies revealed that pseudo-second-order model and Langmuir isotherm fitted better by experimental data. According to the obtained thermodynamic parameters such as Δ G ∘ (free energy), Δ H ∘ (enthalpy) and Δ S ∘ (entropy) the adsorption was spontaneous, favorable and naturally exothermic process. Moreover, reusability of the synthesized sorbent evaluated in five continuous cycles of sorption–elution process that slight decrease was observed.

Modeling low temperature plasma gasification of municipal solid waste

Abstract: Plasma gasification requires high energy input and temperature, hindering adoption for commercial applications. In this study, a model of low-temperature plasma gasification is investigated to convert municipal solid waste (MSW) into syngas. The model was employed at reactor temperatures of 1,500, 2,000, and 2,500 °C to assess effects on syngas composition and system performance with air as the plasma medium. At plasma temperatures of 1,500, 2,000, and 2,500 °C, the model generated syngas lower heating values of 5.41, 6.02, and 6.45 MJ/Nm3, respectively, with energy inputs of 2,358, 2,775, and 3,245 kW per kg/s of MSW, respectively, and plasma gasification efficiencies of 49.6, 49.2, and 48.9%, respectively. In comparison to conventional non-plasma air gasification of MSW, syngas generated from low-temperature plasma gasification contained higher concentrations of hydrogen and carbon monoxide, resulting in higher heating value of the syngas.

Production of biosurfactant from agro-industrial waste by Bacillus safensis J2 and exploring its oil recovery efficiency and role in restoration of diesel contaminated soil

Abstract: In this study, biosurfactant production by Bacillus safensis J2 in submerged fermentation employing agro-industrial waste (bagasse) as a sole carbon source was examined. Biosurfactant produced was characterized to predict its properties and stability to various environmental stresses. Further, the strain and its extracted biosurfactant was used in oil recovery operation and in restoration of diesel contaminated soil. Findings suggest that bagasse of sugarcane may serve as an efficient substrate for cost-effective production of biosurfactant as 0.92 ± 0.06 g/L of biosurfactant by the strain was produced in 15 g bagasse. Stability studies indicate that properties of the biosurfactant were stable at various temperature and pH and have the efficiency to persist its emulsification activity at varying salt concentration. Oil recovery operation demonstrated that the biosurfactant is effective in recovering up to 46.5 % of the trapped oil from the sand pack column and acute earth worm toxicity test reveal that the soil treatment E5 (100 g soil + 10 g Bagasse + 250 ml distilled H 2 O + 10 ml diesel oil+ Strain J2+ 25 ml crude Biosurfactant) is effective in restoration and detoxification of diesel contaminated soil.

Biodegradation of bisphenol A by bacterial consortia isolated directly from river sediments

Abstract: Bisphenol A (BPA) is an endocrine disrupting compound (EDC) of emerging concern because of its capability to mimic hormonal functions causing adverse health effects in human and aquatic life. Due to its ubiquitous presence in air, water, and soil, the removal of BPA from the environment has become a pressing issue. This study investigated promising microbial systems to remove BPA using three bacterial strains (HAWD1, HAWD2, and HAWD3) and a bacterial consortium (BCC1) isolated directly from the sediment of the Rio Grande River. In the culture media spiked with BPA as the sole carbon source, the growth of the bacteria, biodegradation kinetics, formation of metabolites, and BPA removal capacity were studied. Three out of six bacterial strains isolated showed an increasing growth in the BPA spiked medium using BPA as their carbon source. The consortium BCC1 of the three strains (HAWD1, HAWD2, and HAWD3) had the highest degree of BPA removal capacity (100%) within 72 h after incubation followed by HAWD1 (95%), HAWD2 (91%), and HAWD 3 (89%). Notably, the consortium had the fastest BPA removal rate and could transform BPA completely to its metabolites in 72 h of incubation. All biodegradation most like followed zero order reaction under the experimental condition. The results demonstrated the BPA degradation ability of a novel microbial system and revealed that microbial diversity could play an important role in BPA and other EDCs decomposition in the environment.

Status of carbon capture and storage in India’s coal fired power plants: A critical review

Abstract: India is a country with developing mixed economy and requires a huge amount of energy to complete industrial as well as daily social need of its countrymen. Majority of its energy demand is going to be fulfill by coal based power plants. The country is heavily reliant on coal used as a primary fuel in power plant. However, the use of coal at higher level polluting the environment in a continuous manner. Alone, India’s power sector is responsible for half of all CO2 emission in the nation and therefore a serious attention is required in this direction to reduce (GHG) emissions in the environment. Presently, Carbon Capture and Storage (CCS) act as a bridging technology and a viable option for coal fired power plants to extract CO2. But, still in India the adoption of CCS in coal fired power plant is poor. In UNFCCCs Paris Summit, India committed to reduce its carbon intensity by 30%–33% by 2030. The present study deals with the scenario of CCS with various challenges and its implementation efforts in India.

Combined ozone oxidation process and adsorption methods for the removal of acetaminophen and amoxicillin from aqueous solution; kinetic and optimisation

Abstract: The growing use of pharmaceuticals raises questions on their potential risk to human health and water quality. This research aimed to introduce a combined treatment technique with high performance in removing pharmaceutical micropollutants (MPs) from aqueous solution. The research included two steps, ozone treatment (first step) and adsorption technique (second step). The elimination of acetaminophen (ACT) and amoxicillin (AMX) with ozone reactor, first step, was optimised by artificial neural network (ANN). The optimisation process included two independent variables, namely, initial concentration of MPs and ozone dosage. On the basis of ANN, the linear regression coefficient denoted by R2 between predicted and experimental MP removals was close to 1. Result displayed that the prediction by the trained ANN is acceptable. Approximately 0.17 mg/L (84.8%) of ACT and 0.16 mg/L (82.7%) of AMX were removed at the initial concentration of 0.2 mg/L and ozone dosage of 15 mg/L. Beside it, ozonation experiments showed that the rate of constant (m − 1 s − 1 ) for ACT and AMX were 2.63 × 106 and 5.98 × 106 respectively. After treating by ozone reactor, water was subjected to pass through the cross-linked chitosan/bentonite as a fixed-bed column, for second step. ACT and AMX were not detected after step 2.

Assessing the feasibility of microalgae cultivation in agricultural wastewater: The nutrient characteristics

Abstract: This study investigated the feasibility of microalgae cultivation using palm oil mill effluent (POME). The availability of nutrient was assessed as well as the components and solubility of those nutrients in POME. The growth of native and commercial strains was evaluatedbased on their specific growth rate ( μ ) and biomass production. Characterization of POME shows high concentration of three essential nutrients; carbon (C), nitrogen (N) and phosphorous (P) at 2364 mg L − 1 , 385 mg L − 1 and 106 mg L − 1 respectively. Crucially, more than 80% of C and N along with 72% of P were in soluble form, thus readily available for microalgae assimilation. Major constitute of N and P were ammonium and phosphate respectively, suitably the preferred form by the microalgae. A native strain, Chlorella sorokiniana produced the highest growth with μ of 0.24 day − 1 . Interestingly, Chlorella sorokiniana obtained from commercial source produced comparable result with μ of 0.23 day − 1 . High concentration of nutrient in POME has resulted in productive accumulation of biomass with both Chlorella sorokiniana species produced more than 100 mg L − 1 day − 1 . Outcome from this study indicated that POME is much suitable option for microalgae cultivation for subsequent production of valuable biomass.

Isolation, structural elucidation and bioherbicidal activity of an eco-friendly bioactive 2-(hydroxymethyl) phenol, from Pseudomonas aeruginosa (C1501) and its ecotoxicological evaluation on soil

Abstract: Agricultural production in many emerging economies suffer losses owing to the challenges posed by weeds. Owing to cost, ecological, environmental and other human health safety issues regarding the use and application of chemicals as a control option against invasive weeds, there has been a renewed focus to explore alternative and safer methods such as biotechnology. In this study, we explored the use of some beneficial rhizobacteria as a possible alternative to chemicals. The impact of the newly characterized strains of rhizobacteria (acting as a bioherbicide), was investigated to ascertain whether they had any impact on the soil health — and here its effect on the soil organic carbon content, soil respiration, and enzymatic activities were investigated. Several bioactive metabolites extracted from the rhizobacteria were further screened (via leaf necrosis assays, under laboratory and screen house), for their selective efficacy against a range of test plants, of which the C1501 strain showed the most promising results for good herbicidal activity. In this study, the active compound is identified by combined spectroscopic methods (1D and 2D NMR techniques) as a 2-(hydroxymethyl) phenol. The C1501 strain were also shown to significantly decrease the dry-weight of A. hybridus seedlings. However, there was no noticeable or adverse effect observed in sorghum seedlings. A low adverse effect on soil was also shown after day 70 of the experiment, where the 2-(hydroxymethyl) phenol treated soil had the highest release of CO2 (867.50 mg CO2 kg−1 soil hr − 1 ) when compared to the glyphosate treated soil (96.73 mg CO2 kg−1 soil hr − 1 ). Similarly, the enzymatic activities and the soil carbon content were significantly higher in the 2-(hydroxymethyl) phenol treated soil when compared to the control. The C1501 strain was found to have an eco-friendly profile; was cheap and could be used as a good alternative product to chemical herbicides. This strain could thus serve as a good candidate bioherbicide for the control of the A. hybridus weed and possibly be considered for use in a large scale production system, which would be beneficial for a sustainable organic agricultural setting that improves yield and enhances food security.

Urea-impregnated HAP encapsulated by lignocellulosic biomass-extruded composites: A novel slow-release fertilizer

Abstract: In the present work, novel composite materials based on coated urea with calcium phosphate encapsulated woodchip species were developed to be used as nitrogen-loaded slow release fertilizers. Urea supported calcium phosphate was used as the basic fertilizer, whereas sugarcane bagasse (Saccharum officinarum L.) and its derivatives such as lignin and cellulose were used as the wood-based coating. The synthesized composite fertilizers were characterized in relation to their structural properties by means of X-ray diffraction and FTIR analysis. The obtained products were evaluated by means of laboratory tests for solubility in water for 60 days. It was found that the rate of urea release in water was slower in the case of coated fertilizer than in the uncoated urea/HAP fertilizer and that the rate of the nutrient release process was noticeably controlled by the coating material type and the calcination temperature of the HAP support. Importantly, the Water immersion release experiments demonstrated that the developed fertilizer displayed a subsequent slow-release of nitrogen even after 60 days of release compared to the pure urea fertilizer, which released rapidly and prematurely all its nitrogen content. The best slow release pattern of urea occurred with the urea coated mesoporous HAP encapsulated by lignin over 60 days of release experiment.

Adsorption and magnetic solid-phase extraction of NSAIDs from pharmaceutical wastewater using magnetic carbon nanotubes: Effect of sorbent dimensions, magnetite loading and competitive adsorption study

Abstract: Magnetic carbon nanotubes (MCNT) of different dimensions and different magnetite-to-carbon nanotube (Mag:CNT) ratios were prepared and characterized for magnetic solid phase extraction (MSPE) of some non-steroidal anti-inflammatory drugs (NSAIDs) (ketoprofen (KET), diclofenac sodium (DIC) and ibuprofen (IBU)) from water prior to their HPLC determination. The results revealed that the best mixing ratio of (Mag:CNT) was at (1:1) ratio; long CNT was better than short CNT; the best external diameter was 60–100 nm. This sorbent was labeled as L-MCNT60-100 nm (1:1). The optimum MSPE-HPLC method was as follows: 150 mg of L-MCNT60-100 nm (1:1) sorbent was added to 50 mL solution containing KET, DIC and IBU at pH 5. The solution was shaken for 30 min and the sorbent was separated from the solution using an external magnet. The adsorbed analytes were eluted using 5 mL of 10% ammonia in methanol and the eluent was then injected into HPLC instrument. Figures of merit were estimated to be as follows (KET, DIC and IBU, respectively): detection limits: 0.4, 0.5, 0.5 μ g L−1; sensitivity: 3.13, 3.40, 1.46 L mg−1; %RSD range: [2.6–7.2], [2.2–5.1], [2.7–6.4] %; bias range (%): [(-26.8)–(14.0)], [(-7.4)–(17.0)], [(-8.4)–(17.8)]%. Application on tap water and pharmaceutical wastewater gave spiked recovery as follows: Tap water: KET: 103.7%( ± 5.4); DIC: 110.3%( ± 5.3); IBU: 70.1%( ± 6.5); Pharmaceutical wastewater: KET: 58.8%( ± 7.2); DIC: 48.9%( ± 5.9); IBU: 100.5%( ± 8.2). Adsorption studies were conducted to measure the adsorption capacity of the adsorbents where the effect of MCNT dimensions, magnetite loading and competitive adsorption were investigated.

Nanopesticidal potential of silver nanocomposites synthesized from the aqueous extracts of red seaweeds

Abstract: In this study, silver nanoparticles (AgNPs) green synthesized using the aqueous extracts of agar seaweeds (Gracilaria corticata and G. edulis) and carrageenan seaweeds (Hypnea musciformis and Spyridia hypnoides) were found effective (antibacterial activity) against Xanthomonas axonopodis pv. citri and X. oryzae pv. oryzae and antifungal activity against Ustilaginoidea virens under in vitro condition. The synthesis of AgNPs due to the reduction of Ag + to Ag 0 observed by the colour change from pale yellow to brown was recorded between 410 nm and 430 nm. The aliphatic amine, alcohols, ether, carboxylic acids, anhydrides and cyclic peptides recorded in the AgNPs by FTIR spectra are the functional groups of protein and sulphated polysaccharides (agar and carrageenan) which involved in the reduction reaction, stability and capping of the NPs. The AgNPs of spherical shape with average size of 37 nm, 54 nm, 53 nm and 49 nm synthesized by G. corticata, G. edulis, H. musciformis and S. hypnoides respectively, were characterized. The DLS study reveals the property of agglomeration instead aggregation in a liquid medium concluding that the AgNPs synthesized using these four red seaweeds found to be a suitable source for nanopesticide formulation.

Response surface methodology based electro-kinetic modeling of biological and chemical oxygen demand removal from sugar mill effluent by water hyacinth (Eichhornia crassipes) in a Continuous Stirred Tank Reactor (CSTR)

Abstract: This study investigated the biological and chemical oxygen demand (BOD and COD) removal from sugar mill effluent by water hyacinth (Eichhornia crassipes). The batch phytoremediation experiments were performed in a Continuous Stirred Tank Reactor (CSTR) assisted with low-level direct current (DC). Response surface methodology (RSM) based electro-kinetic modeling and optimization was done using a Central Composite Design (CCD) of 19 experimental runs. A total of three initial BOD/COD dose ( X 1 : 50, 475 and 900 mg/L) with stirring rates ( X 2 : 0, 15 and 30 rpm) and DC current ( X 3 : 0, 1 and 2 Volts) were chosen as independent variables to optimize percent BOD and COD removal by E. crassipes, separately. Results showed that the quadratic model was best fitted in the data and had high R2 value (0.98), low P value ( − 1 and 0.9069 mg/Lw−1 for BOD and COD, respectively. This study emphasized a novel method for effective approach to reduce BOD and COD load of sugar mill effluent using E. crassipes in CSTR assisted with low-level DC current.