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Commercial starch extraction is a multi-step process which requires high capital cost and infrastructure. The present study aimed at exploring a low cost process for small scale/on-farm processing of potato for isolation of starch which included potato grinding, slurry filtration, starch settling, increased number of starch washings to obtain maximum yield and purity followed by starch drying. Two commercial cultivars (Kufri-Chipsona-3 and Lady Rosette) and two commonly grown cultivars (Kufri Pukhraj and Kufri Ganga) were used for the experiments. The isolated starches varied significantly (p

To control the total treatment cost of textile dye effluent a new advanced combined treatment technology has been investigated. Advanced oxidation processes like ozonation have much potential to degrade dye but its main drawback is high cost. To reduce the cost of ozonation for dye degradation and decolourization, ozonation followed by anaerobic biodegradation using upflow anaerobic sludge blanket (UASB) reactor was carried out. The synthetic textile wastewater containing Reactive Black 5 has been used in this study by this combined treatment process. The system of ozonation and anaerobic treatment by UASB reactor showed that the chemical oxygen demand (COD) reduction has reached to about 90% and dye removal 94% respectively. Combined treatment enhanced the overall color removal up to 10 on platinum cobalt (Pt–Co) scale. Thus the combined treatment process results in high color, COD and total organic carbon (TOC) removal efficiency which would minimize the overall treatment cost. Dye degradation products were analyzed by ion chromatography (IC) and UV–vis spectroscopy.

Arsenic is present in groundwater in some parts of India. Despite the fact that a variety of treatment methods are available, the efficiency of these methods is not fully known. With the revision of Indian standards for permissible levels of arsenic in drinking water to 10 μg/L or lower, it is necessary to develop a treatment method, which meets drinking water standards of 10 μg/L. Iron based adsorbents have been reported to have high affinity for arsenic. Many researchers have also shown that the corrosion of Zero Valent Iron (ZVI) forms Hydrous Ferric Oxide (HFO) which can act as an adsorbent for arsenic. And the oxidation of Fe to Fe has also been reported to oxidize As(III) to As(V). Using this information a ZVI based Arsenic Filter has been developed by Indian Institute of Technology, Bombay. Test units of the IITB-Arsenic Filter have been installed in the field in four villages in West Bengal. From the results, it is clear that the filter is able to consistently achieve arsenic levels around 10 μg/L for initial arsenic concentrations ranging from 0.06 to 0.4 mg/L. The flowrate of the filtered water is aprox. 600 L/hr. Thereby the IITB-Arsenic Filter is able to consistently provide drinking water for about 200 families on a daily basis. The IITB-Arsenic Filter does not require frequent backwashing/cleaning (cleaning frequency is once in 3 months, and is done by the villagers) and therefore has low operation and maintenance costs. Moreover, it does not require monitoring of flow parameters and is easy-to-operate by unskilled personnel. The Fe/As ratio used in the filter is around 20. Low Fe/As ratios mean lesser sludge generation. Thus it is felt that the IITB Arsenic filter is a suitable technology for rural India.

Soda-alkaline method of alunite ore processing includes crushing, grinding and enrichment (flotation) of the alunite ore. Enriched alunite ore, containing 50 - 60% of alunite, is roasted at temperatures between 520о – 620о С for 1 – 3 hours. Roasted alunite is further leached with sodium carbonate solution (5–20 %). Proportion of sodium carbonate for binding of SO3 aluminum sulfate in alunite accounts for 100 – 110 % of stoichiometric quantities. Leaching takes place at temperatures around 70 – 100о С for 0.5 – 2.0 hours. Solution of the resulting pulp contains all the potassium sulfate from alunite and sodium sulfate from soda. Solution of sulfates is separated from the insoluble residue and is fed for conversion with potassium chloride. As result of this conversion we obtain quantities of potassium sulfate (fertilizer) and table (common) salt. The remaining insoluble residue contains all the aluminum oxide from alunite and waste rock. Further processing of the insoluble residue based on the Bayer out-of-autoclave process produces alumina and quartz sand. Besides alumina, this method makes it possible to get four times more the amount of potassium sulfate and certain volumes of table salt. Taking into account the processing capacity of Ganja Alumina Plant (150,000 tons of alumina per year), this method allows the production of fertilizer, potassium sulfate (370,000 tons per year), coagulant for purification of water from mechanical impurities (49,000 tons per year), table salt (NaCl) (126,000 tons per year), and quartz sand for non-ferrous casting and production of construction materials (300,000 tons per year). Approximate yearly financial efficiency of the soda-alkaline technology for processing of 150,000 tons of alumina per year will be around 171,46 million USD.

Cryogenic condensation is an extremely cost-effective technology for controlling emissions of Volatile Organic Compounds (VOCs) from chemical processing facilities under certain conditions. This paper describes the technology and provides the case history of an application in the pharmaceutical industry, in which its cost effectiveness was compared with a range of alternative technologies, including thermal oxidation, catalytic oxidation, flaring, carbon adsorption, and scrubbing. Because the facility already used significant quantities of liquid and gaseous nitrogen for inerting, blanketing, and purging, a very convenient cold source for cryogenic condensation was already present. On a lifetime cost basis, cryogenic condensation was significantly less costly than all other technologies evaluated.

In situ bioreclamation is a proven technology that cost-effectively treats organic contamination in subsurface environments. As a remediation strategy, it reduces both the contamination dissolved in ground water, as well as residual soil-bound contamination. To maximize biodegradation, the technology is applied after conducting laboratory studies. Application of the technology involves infiltrating necessary nutrients to the contaminated subsurface. Results of a specific case study indicate excellent performance with rapid cleanup of petroleum hydrocarbon contamination from soils and ground water. Costs associated with in situ bioreclamation technology showed a savings of approximately 50 percent over simple pump-and-treat technology. Time frame for cleanup was shown to be approximately 30 percent of the projected time frame of simple pump-and-treat technology.

Hyderabad city is an emerging pharmaceutical hub of India. Pharmaceutical effluent contains many organic and inorganic compounds which need to be treated before discharging into natural water bodies or municipal sewers. The disposal of these wastes should be done in a safe, secure and aesthetic way failing which, results in harmful effects on human, plant and animal life. In the present study effluent from a pharmaceutical industry in Hyderabad, manufacturing Active Pharmaceutical Ingredients (APIs) and solid oral dosage forms is analyzed. It was found to contain large amounts of Dissolved solids, COD, Suspended solids, chlorides and colour. In this paper a comparative study of Chemical coagulation and Electrocoagulation in treating the effluent is made to find a more efficient and cost-effective technology. The results showed that though chemical coagulation has brought a considerable decrease in percentage of COD, suspended solids and chlorides, but the extent of decrease in the Total Dissolved Solids (TDS) is only 14.05 % using Alum and 26.3 % with FeCl3. Whereas electrocoagulation method which has reduced both COD and TDS to greater extent (92.3 % & 91.5 %) proved more efficient with Fe-Al assembly using a lowest current of 0.04 A at a time interval of 15 min. The coagulant consumption is also less in eletrocoagulation compared to chemical coagulation rendering it a cost effective technology.

Recent advances in nanotechnology have witnessed tremendous progress concerning nanofiber synthesis and practical applications. Electrospinning is a simple, versatile, and cost-effective technology that relies on electrostatic repulsions between surface charges to continuously fabricate various scalable assemblies from a wide range of raw materials (polymers, ceramics, nanoparticles, carbon nanomaterials, gels, etc.) with diameters down to macro-nano scale. Nanofibers prepared by electrospinning possess remarkable large and specific surface area to volume ratio, interconnected and tunable structures, diverse morphologies, physio-chemical and mechanical properties. In this paper, Polyvinylidene fluoride (PVDF) nanofibers with different concentrations and under constant electrospinning conditions have been prepared and characterized. The increase of the PVDF polymeric concentration improved the morphological structure of the PVDF nanofibers due to the enhanced molecular chain entanglement which allows the stretching and elongation of the fibers during the electrospinning process. At higher PVDF concentration, the fiber diameters become thinner and beadless nanofiber mats are obtained. Finally, the potential practical applications of electrospun PVDF nanofibers are addressed in this paper.

Phytoremediation is a novel and cost-effective technology for removing contaminants from soil. This study investigated the effect of Chitosan (CS) and Chitosan nanoparticles (CSNPs) on phytoremediation ability of Datura stramonium L. for Cadmium (Cd) polluted soils. The results showed that D. stramonium is an accumulator plant for Cd, with the translocation factor (TF) of 1.12. Its accumulation ability was increased by the application of CS and CSNPs considerably. The concentration of Cd, in the soil, was decreased by increasing application of CS and CSNPs; also CSNPs were more effective in enhancing phytoremediation of Cd, in compared to CS. The application of CS and CSNPs significantly increased the bioconcentration factor (BCF) and TF. The highest BCF (1.85) and TF (1.65) were observed in the group treated by 5% CSNPs, showing the best function for phytoremediation of Cd. Increasing the uptake of Cd, after the CSNPs treatment, could be described as an effect of the small size, higher surface area and the low crystallinity of the nanoparticles. In the leaves of the plants treated with Cd + CS and Cd + CSNPs, the total protein content decreased in comparison to Cd- treated plants, that is the sign of Cd resistance in D. stramonium. Application of CS and CSNPs caused the increase in the peroxidase and polyphenol oxidase activities as compared to the group treated just by Cd. The results, therefore, demonstrated that D. stramonium could be suitable for phytoremediation of Cd-contaminated soils and application of CS and CSNPs could enhance BCF and TF.

This work investigates the effectiveness of ammoniacal nitrogen (NH 4 + -N) removal from contaminated water by adsorptive hollow fiber ceramic membrane (HFCM) derived from naturally made clinoptilolite. The technological value of this work is the simple mechanism of the adsorptive HFCM in removing gaseous ammonia in water by combining adsorption and separation. To test the technical feasibility of this proposed technology, clinoptilolite HFCM was fabricated via phase inversion-based extrusion/sintering technique and characterized by SEM and water permeation flux. The produced HFCM corresponds to the desired morphology of the asymmetric structure (dense and void formations) with outstanding adsorption performance of NH 4 + -N. The effects of the HFCM’s operational parameters on its removal are examined in terms of membrane dosage and isothermal studies. The adsorption isotherm behavior exhibited that the adsorption process fitted the Freundlich isotherm model with outstanding removal performance even at trace concentration of ammonia. The low amount used by HFCM (4.75×10−4m2) resulted in over 96% ammonia removal, indicating a low cost of adsorption process. The regeneration of saturated HFCM suggests an outstanding recovery of the HFCM for its subsequent use for NH 4 + -N removal. This study also reveals the potential of adsorptive HFCM as a simple and cost-effective technology for ammonia removal from wastewater.

Reducing the atmospheric CO2 level is of a great interest these days, as it is negatively affecting our environment. Despite the large efforts invested in development of technologies for CO2 fixation, there is still no large-scale, man-made solution to deal with it. A useful strategic solution is to retrieve CO2 from the air and to reduce it into valuable products, to establish a closed carbon cycle. Reduction of CO2 by electrochemical means seems to be the most practical and economical alternative, but there is still much to be done in terms of catalysts’ development, to enable energy-efficient and cost-effective technology at-scale. In this mini-review, we will focus on the progress that has been made in the area of first-row transition metals complexes as catalysts for CO2 electro-reduction, mostly under conditions that are relevant for large scale applications.

BACKGROUND: Microbial degradation of organophosphorus (OP) insecticides has emerged as an efficient and cost‐effective technology for removal of pesticide residues from soil. Malathion‐tolerant Aspergillus (Aspergillus niger MRU01) was developed, mass cultured, harvested, mixed with coir pith at 3% on dry weight basis, shade‐dried aseptically to a 5% moisture level and stored for 60 days. The growth, metabolic activity and insecticide removal efficiencies of the preparation were evaluated at 15‐day intervals. RESULTS: No significant change in the growth performance was observed up to 45 days of storage, after which viability decreased. The activities of carbohydrate enzymes (cellulase, invertase and amylase) and protein and carbohydrate contents of the preparation, however, did not significantly change during the experimental period. The preparation showed accelerated activities of esterases and phosphatases after treatment with malathion (500 μmol L⁻¹), parathion (470 μmol L⁻¹), chlorpyrifos (260 μmol L⁻¹) and dimethoate (680 μmol L⁻¹). The highest activity of the esterase and phosphatase enzymes was observed with malathion and the minimum with parathion treatment. Nearly 70% of the applied malathion was removed from the medium by the preparation during 5 days of incubation followed by dimethoate (68%), chlorpyrifos (58%) and parathion (54%). CONCLUSIONS: The fungal preparation was highly effective in removing malathion as well as the other three OP insecticides. A storage period of 45 days may be considered ideal for maintaining the preparation in the active state, and is recommended for field application after evaluating its efficacy under field conditions. © 2021 Society of Chemical Industry

The main objective of the present study was to demonstrate microaeration as an effective strategy to boost the biotransformation of four parabens (methylparaben, ethylparaben, propylparaben, and butylparaben) in an upflow anaerobic sludge blanket reactor operated at a short hydraulic retention time (8 h). Moreover, the effect of different airflow rates (1−4 mL min−1) was also assessed from an engineering and microbiological perspective. Low mean removal efficiencies (REs) (14–20 %) were achieved under anaerobic conditions. However, the addition of only 1 mL air min−1 (0.027 L O2 L−1 feed) remarkably boosted the biotransformation of parabens, ensuring mean REs above 85 % for all compounds. In contrast, the increase in the airflow rate had a minor impact on the process, and an apparent saturation in the removal capacity was observed, noticeably from 2 to 4 mL air min−1. The reactor presented high stability throughout the experiment, and microaeration did not impair the organic matter removal and methanogenesis. However, high airflow rates can dilute biogas, compromising its use as a fuel in combined heat and power units. The microaerobic conditions increased both richness and diversity of the reactor’s microbiota, likely favoring the growth of oxygenase-producing microorganisms, which may have played a role in the biotransformation of parabens. Finally, the high REs of parabens reached in the microaerated reactor, a more cost-effective technology, are comparable to those found in high-cost wastewater treatment systems, such as activated sludge and its variants.

Microbial Fuel Cells (MFCs) offer a sustainable solution for alternative energy production by employing microorganisms as catalysts for direct conversion of chemical energy of feedstock into electricity. Electricity from urine (urine-tricity) using MFCs is a promising cost-effective technology capable of serving multipurpose benefits - generation of electricity, waste alleviation, resource recovery and disinfection. As an abundant waste product from human and animal origin with high nutritional values, urine is considered to be a potential source for extraction of alternative energy in the coming days. However, developments to improve power generation from urine-fed MFCs at reasonable scales still face many challenges such as non-availability of sustainable materials, cathodic limitations, and low power density. The aim of this paper was to critically evaluate the state-of-the-art research and developments in urine-fed MFCs over the past decade (2008-2018) in terms of their construction (material selection and configuration), modes of operation (batch, continuous, cascade, etc.) and performance (power generation, nutrient recovery and waste treatment). This review identifies the preference for sources of urine for MFC application from human beings, cows and elephants. Among these, human urine-fed MFCs offer a variety of applications to practice in the real-world scenario. One key observation is that, effective disinfection can be achieved by optimizing the operating conditions and MFC configurations without compromising on performance. In essence, this review demarcates the scope of enhancing the reuse potential of urine for renewable energy generation and simultaneously achieving resource recovery.

In this work, glycolysis of post-consumer polyethylene terephthalate with simultaneous dissolution and decomposition with a mixture of bis(2-hydroxyethyl) terephthalate and its oligomers is studied. High efficiency of this process was shown. For the glycolysis agent containing 75 wt% bis(2-hydroxyethyl) terephthalate and 25 wt% dimer and oligomers, the optimal molar ratio of the glycolysis agent units to the polyethylene terephthalate units is 5:1. On the basis of the process, a productive and cost-effective technology can be developed for the chemical destruction of post-consumer polyethylene terephthalate. A formula for calculating the bis(2-hydroxyethyl) terephthalate conversion taking into account the presence of oligomers in it is proposed.

Microalgae readily develop tolerance against environmental pollutants and are also capable of utilizing heavy metals in their metabolic activities. Microalgae-based heavy metal removal provides an eco-friendly, cost-effective technology to treat wastewater. In this study, a strain of the green alga Chlorococcum aquaticum, isolated from water polluted with Pb2+, was selected for bioremediation of Pb2+ in aqueous solutions. Chlorococcus aquaticum showed a high level of tolerance toward Pb2+ with an LC50 of 100 mg L−1. To assess the efficacy and practicality of the bioremediation process, adsorption isotherms and kinetic models were developed. The best-fitted adsorption model was Freundlich isotherm with the adsorption constant (KF) = 2.18 mg g−1 and n = 1.01, suggesting a multilayer adsorption to heterogeneous surfaces. The kinetic studies revealed that the interaction of Pb2+ with C. aquaticum obeys pseudo second-order kinetics with the rate constant (k′) = 1.21 × 10−5 g mg−1 min−1 and the amounts of Pb2+ adsorbed per gram of adsorbent at equilibrium (qe) = 500 mg g−1, indicating that the rate determining step involves a chemical reaction mechanism. Chlorococcum aquaticum showed a high tolerance toward Pb2+, high adsorption capacity and a moderate adsorption rate. Thus, growing C. aquaticum can be identified as a potential environmentally friendly and low-cost sorbent to remove a wide range of Pb2+concentrations from wastewater.

Aqueous rechargeable zinc–iodine batteries are emerging high-safety and cost-effective technology for large-scale energy storage. However, the high solubility of discharge species polyiodide in aqueous electrolyte is the major challenge for iodine cathode. Herein, the polyiodide doped conductive polymer cathode is proposed to suppress the dissolution of active materials in electrolyte. High reversible capacity of 160 mAh/g and remarkable cycling stability with capacity retention of 79% after 700 cycles at 1.5 A/g are achieved.

Routine analytical methods are constrained in the speed of application, sample throughput and inability to determine the right bioavailable loading of pollutants. Microbial biosensor technology resolved these constraints by offering the most rapid, sensitive, reliable and cost-effective technology, especially in a bioavailable context. This study describes the growth characterisation and optimisation of three different lux-marked biosensors and their induction bioassay, thus testing their responses to doses of target hydrocarbons (naphthalene, toluene, Isopropylbenzene) and solution of mixed hydrocarbons. These biosensors, Pseudomonas fluorescence HK44, Escherichia coli HMS174 and Pseudomonas putidaTVA8 harbours luxCDABE reporter genes coupled to induction by hydrocarbons. Biosensors harvested at optimal exponential phase and induced with hydrocarbon using the optimised assay conditions are highly sensitive and responsive to their inducers in a proportionate dose-dependent status. The established dose responses of these catabolic biosensors signify the prospect of extrapolation for estimating the genuine contamination loading of pollutants for environmental relevance. However, several factors may contribute to the quenching effect at high concentration of inducers. Robust responsiveness to mixed hydrocarbon solution has been also realised accentuating its feasibility in analysing of real environmental samples containing heterogenous pollutants. This study emphasises the suitability of bioluminescent bacterial biosensors for pollutants analysis and notably the detection of soluble bioavailable fractions of diverse hydrocarbons, hence, serves as a reliable bioindicator of hydrocarbon pollution in an environment. Even so, the real value of biosensors is for a suite of ecologically justified biosensors to be applied in complementary combinations with other focused analytical or chemical methods for broad and resourceful inference.

Reducing input of phosphorus is the key step for control of eutrophication and algal blooming in freshwater lakes. Adsorption technology is a cost-effective technology for phosphate removal in water for the purpose. Thus, in this study, a novel Fe–Mn–La tri-metal composite sorbent was developed, and then evaluated for phosphate removal. The results showed that the maximum adsorption capacity could be approached to 61.80 mg g−1 at 25°C under pH of 6.03. Adsorption of phosphate by Fe–Mn–La tri-metal composite adsorbent fitted better by pseudo-second-order kinetic equation and Langmuir model, which suggested that the adsorption process was surface chemical reactions and mainly in a monolayer coverage manner. The thermodynamic study indicated that the adsorption reaction was an endothermic process. The phosphate removal gradually decreased with the increasing of pH from 3.02 to 11.00. The sequence of coexisting anions competing with phosphates was that CO32− > Cl− > SO42− > NO3−. Dissolved organic matter, fulvic acid as a representative, would also decrease adsorption capacities of phosphate by Fe–Mn–La tri-metal composite adsorbents. Adsorption capacity would be decreased with increasing addition of adsorbents, while removal efficiency would be increased in this process. The Fe–Mn–La tri-metal composite adsorbent showed a good reusability when applied to removal of dissolved phosphate from aqueous solutions. The Fourier transform infrared spectrometer and X-ray photoelectron spectroscopy analyses indicated that some hydroxyl groups (–OH) on the surface of adsorbent were replaced by the adsorbed PO43−, HPO42−, or H2PO4−. Aggregative results showed that the novel Fe–Mn–La tri-mental composite sorbent is a very promising adsorbent for the removal of phosphate from aqueous solutions.

Lateral flow assays (LAFs) especially integrated with a microfluidic chip, provides a simple, rapid, user-friendly, potable robust, and cost-effective technology for broad assays. However, this technology suffers from low sensitivity. In this paper, one kind of automatic roller of tap, which can be precisely controlled to replace sample tap was integrated into the microfluidic LAFs platform. And then, on-stripe repeated injection and concentration were realized with this simple mechanic unit. The minimum detection concentration for human chorionic gonadotropin (HCG) was 1.26 ng/mL, comparable with literature using complex enzyme/chemical reaction-based signal amplification. The linear relationship between the signal intensity and enrichment times reflected the good reproducibility of the novel device. At the same time, the good linear relationship between the predicted accumulation quantity of HCG and the gray value of bands is very meaningful for quantitative detection. Consequently, this novel universal approach shows great potential in the rapid trace analysis and broaden the application of LAFs with its attractive characteristics.

Sodium-ion batteries (SIBs) are now intensively developed as a cost-effective technology alternative to lithium-ion batteries (LIBs) for large-scale energy storage because of their various advantages such as huge abundance of sodium resources, highly safe and significantly low cost. Among many other cathode materials, layered 3d-transition metal oxides (LTMO-NaxMO2, x ≤ 1 and M = Co, Ni, Mn, Cr, Cu, Fe and V) have gained an enormous interest and attractive attention among researchers because of their low-cost, high energy density and ease of synthesis. In addition, LTMOs offer higher reversible capacities because of relatively lower molecular weights; however, complex phase transformations limit their cycling life. Based on the previous research, it was examined that the crystalline phase of LTMO highly influences the electrochemical performance of SIBs; therefore, this review mainly focuses on the latest advances of various crystalline phases such as P2-type, P3-type, O3-type and biphase/multiphase materials and its strength as well as future prospects and challenges.

In Arequipa (Peru), a small-scale tannery industry cannot afford costly or complicated methods for effluent treatment. In this work, we designed and tested a bubble column bioreactor for tannery effluent treatment based on the native filamentous fungi Penicillium citrinum and Trichoderma viride. The bioreactor construction used low-cost materials, with an easy-to-handle design. The parameters considered for testing were based on current Peruvian legislation. In the bioreactor, P. citrinum successfully reduced the effluent content of sulfides, chemical oxygen demand (COD) and total suspended solids (TSS) and removed nearly 80% of the chromium (VI) after 120 h of reaction. The resulting treated effluent had a composition within the maximum limits permitted by Peruvian legislation. Trichoderma viride also reduced the content of TSS, COD and sulfides, but decreased the chromium (VI) concentration by only ~ 20% after the same reaction time. Both filamentous fungi were able to grow in the experimental conditions used and the bioremediation process occurred with no significant alteration in pH. These findings indicate that a bubble column bioreactor using P. citrinum as a bioremediator agent provides low-cost, effective technology for treating effluent waste produced by artisanal and small-size tannery factories in the region of Arequipa.

Heavy metal pollution threatens aquatic systems worldwide, and mining activities are an important pollution source. Currently, the treatment of polluted water using a cost-effective technology that can purify multiple pollutants and is sustainable, environmentally friendly, and simple is a major challenge. The in situ preparation of Mg–Al layered double hydroxides (LDHs) and the concurrent treatment of Zn, Cd, and Pb from mining wastewater are important for preventing multiple steps and increasing adsorption sites. This study focused on mining wastewater containing high concentrations of Mg2+ and Al3+, with anion chemistry controlled by SO42−, which facilitates the formation of LDHs. The required amounts of Mg2+ and Al3+ ions were added to the wastewater, and the conditions for the creation of Mg–Al LDHs were controlled. The heavy metals in the experimental wastewater were effectively removed after the treatment via Mg–Al LDH formation. The X-ray diffraction of the post-treatment products suggested the formation of Mg–Al LDHs. The Mg/Al molar ratio (2.3:1) in the product approached the initial ratio (2:1), which meets the general limits of Mg–Al LDH formation. Scanning electron microscopy revealed that the products had a sheetlike stacked morphology, providing evidence for the formation of Mg–Al LDHs. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy indicated that SO42− might be the intercalated anion in the Mg–Al LDH layers. Consequently, SO42− was removed from the mining wastewater, as it was captured between the LDH layers during the formation reaction of Mg–Al LDHs.

Plant incineration ash is the final product from the remediation of multi-metal contaminated soils by the phytoextraction process. The content of heavy metals in plant ash was found to be higher than the regulatory criteria and it was thus classified as hazardous waste. So far, no eco-friendly and cost-effective technology has been developed for the management of this residue. Herein, a cleaner strategy of bioleaching combined with brine leaching of multi-metals from plant ash was developed. The bioleaching results indicated that 88.7% (Zn), 93.2% (Cd), 99.9% (Mn) and 13.8% (Pb) were achieved under optimum conditions of Fe(II) concentration 6.0 g L−1, pH 1.8 and pulp density 15% (w/v). Subsequently, the introduction of brine leaching using 200 g L−1 NaCl significantly increased Pb recovery to 70.6% under conditions of 15% (w/v) pulp density, thereby ultimately achieving deep recovery of all metals. An investigation of the mechanism revealed that H+ attack and microorganisms were the dominant mechanism for bioleaching of Zn, Cd and Mn, and the bioleaching kinetics of Zn in ash were controlled by interface mass transfer and diffusion across the product layer. Risk assessment tests indicated that the leached residues could pass the TCLP test standard and be safely reused as nonhazardous materials. These findings demonstrated that the two-stage leaching strategy was feasible and promising for multi-metal removal from plant ash.

Capacitive deionization (CDI) technologies have gained intense attention for water purification and desalination in recent years. Inexpensive and widely available porous carbon materials have enabled the fast growth of electrosorption research, highlighting the promise of CDI as a potentially cost-effective technology to remove ions. Whereas the main focus of CDI has been on bulk desalination, there has been a recent shift towards electrosorption for selective ion separations. Heavy metals are pollutants that can have severe health impacts and are present in both industrial wastewater and groundwater leachates. Heavy metal ions, such as chromium, cadmium, or arsenic, are of great concern to traditional treatment technologies, due to their low concentration and the presence of competing species. The modification/functionalization of porous carbon and recent developments of faradaic and redox-active materials have offered a new avenue for selective ion-binding of heavy metal contaminants. Here, we review the progress in electrosorptive technologies for heavy metal separations. We provide an overview of the wide applicability of carbon-based electrodes for heavy metal removal. In parallel, we highlight the trend toward modification of carbon materials, new developments in faradaic interfaces, and the underlying physico-chemical mechanisms that promote selective heavy metal separations.

Due to their extensive use, petroleum hydrocarbons are among the most common groundwater contaminants. Compared to the traditional methods of physical pumping of contamination from the aquifer and subsequent treatment (i.e., pump and treat), bioremediation is an economically cost-effective technology. The aim of this remediation approach is to transform biologically contaminants, most often by microbiological activity, into non-toxic compounds. More precisely, it is an active remediation process that involves biostimulation (increase of aquifer oxygenation, addition of nutrients) and/or bioaugmentation (injection of a concentrated and specialized population of microorganisms). Using both biostimulation and bioaugmentation, enhanced in situ groundwater bioremediation was applied at a hydrocarbon-contaminated site in Belgrade. The bioremediation treatment, applied over twelve months, was highly efficient in reducing the concentrations of total petroleum hydrocarbon (TPH) to acceptable levels. The concentration of TPH in the piezometer P-5 was reduced by 98.55 %, in the piezometer P-6 by 98.30 % and in the piezometer P-7 by 98.09 %. These results provided strong evidence on the potential of this remediation approach to overcome site-limiting factors and enhance microbiological activity in order to reduce groundwater contamination. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III 43004]

Due to the deliberate disposal of industrial waste, a great amount of petroleum hydrocarbons pollute the soil and aquatic environments. Bioremediation that depends on the microorganisms in the removal of pollutants is more efficient and cost-effective technology. In this study, five rhizobacteria were isolated from Phragmites australis roots and exposed to real wastewater from Al-Daura refinery with 70 mg/L total petroleum hydrocarbons (TPH) concentration. The five selected rhizobacteria were examined in a biodegradation test for seven days to remove TPH. The results showed that 80% TPH degradation as the maximum value by Sphingomonas Paucimobilis as identified with Vitek® 2 Compact (France).

Lipid productivity of microalgae depends considerably on the method of its cultivation. In the present study, a two-stage culture strategy was conducted to cultivate Chlorella vulgaris to enhance lipid productivity. In the first stage, C. vulgaris was grown in the synthetic medium to obtain maximum biomass concentration. Wastewater is used as a medium for growing microalgae to have commercial and environmental aptitudes for biomass production. The nutrient removal efficiencies were 80.5% (COD), 70% (TN), and 78% (TP). In the second stage, the synergistic effects of nitrogen and NaCl concentration on the lipid productivity was investigated by response surface methodology (RSM) for 2 days. The optimum conditions for relatively high lipid productivity (up to 80 mg L−1 day−1) were 2.6 mg L−1 of nitrogen, 6.3 g L−1 of NaCl, and 4.9 g L−1 of biomass concentration. The value which was predicted by model was in good agreement with the experimental value, as it was determined by the validation experiments. Saturated fatty acid composition was increased by 27.3% under optimized medium compared with synthetic medium, which is very suitable for biodiesel production. According to the above results, it is concluded that the combination of multiple stress conditions can lead to a cost-effective technology of microalgae lipid production.

Catalytic oxidation is an efficient and cost-effective technology to eliminate HCHO, and MnO2 shows excellent performance towards this kind of reactions. In this work, a birnessite type manganese dioxide nanoparticles modified silica-doped titanium dioxide (MnO2@SiO2–TiO2 ) nanofibrous membranes were successfully synthesized by using an electrospinning technique and liquid phase synthesis . It is found that MnO 2@SiO2–TiO2-4 nanofibrous membrane showed the best catalytic activity for HCHO removal. The as-fabricated nanofibrous membranes exhibited good and reversible catalytic oxidation activity towards formaldehyde, and more than 90% of the catalytic performance could remain after 5 testing cycles. The successfully constructed MnO2 nanoparticles decorated soft SiO2–TiO2 nanofibrous membranes, which can be a great promise for effectively solving the problem of environmental remediation.

Fresnel-based concentrated photovoltaic (CPV) solar power systems have been proven effective to significantly enhance the photoelectric conversion efficiency, but a standard-size solar plant will require an extremely large amount of polymer radial Fresnel lenses. Roll-to-roll (R2R) manufacturing is a high-throughput technology to mass produce high-quality functional optical polymer film. In this paper, we have firstly studied a complete manufacturing cycle for R2R embossing of radial Fresnel lens polymer film for CPV systems, in terms of polymer lens design, roller mold machining, R2R embossing and optical performance test. Instead of wrapping an electroplated metal sheet onto the roller in conventional R2R process, the lens pattern array is directly machined using a 5-axis ultra-precision machining system to guarantee its surface quality and accuracy. Optical performance evaluation for the manufactured polymer film using a reference solar cell is conducted, and results have shown that radial Fresnel lens on the polymer film can achieve a sunlight concentration ratio 3.9 × times that of linear lenses with a much smaller receiving area. This study has explored the feasibility for R2R embossing of optical polymer film, an industry-applicable and cost-effective technology for mass production of high-quality Fresnel lenses to be used in high-efficiency CPV systems.

This study aims at analyzing and comparing several indices that evaluate the performance of different grid connected photovoltaic technologies, namely amorphous silicon (a-Si), Polycrystalline silicon (pc-Si), and Monocrystalline silicon (mc-Si) generating around 2 kWp each and set up a forecast studies for future perspectives. These technologies are connected to a low voltage (400 V) three phase electrical grid of Al Akhawayn University (33° North, 5° West) facing south on a flat surface, 32° tilted with zero azimuth, and without including any tracking system. This work is done within the framework of Propre.ma project aiming at establishing a photovoltaic yield maps throughout Morocco. The experimental and theoretical horizontal irradiances of Ifrane's region, simulated with the Davies and Hay model on the MATLAB's software, are compared in the following study. Besides, the evaluation of different technologies is based on the (annual/monthly/daily) AC energy output, the performance ratio, the system efficiency, and the capacity factor that are calculated and measured from data gathered between October 2014 and the end of 2018. An economic analysis was carried out in order to define the levelized cost of electricity of the three technologies. Eventually, the obtained results confirm that the polycrystalline technology is the most cost-effective technology for the region of Ifrane.

The viable chelator-based soil washing has yet to be demonstrated on a larger scale. Soil containing 1850, 3830 and 21 mg kg$^{−1}$ Pb, Zn and Cd, respectively, was washed with 100 mmol EDTA kg$^{−1}$ in a series of 16 batches (1 ton soil/batch) using the new ReSoil® technology. The ReSoil® recycled the process water and 85% of the EDTA, producing no wastewater and 14.4 kg ton$^{−1}$ of waste. The soil washing removed 71, 28 and 53% of Pb, Zn and Cd, respectively, mainly from the carbonate fraction, saturated the soil with basic cations and increased the soil pH by up to 0.5 units. Raised beds (4 × 1 × 0.5 m) with original (contaminated) and remediated soil were constructed as lysmeters, and local produce was grown from July 2018 to November 2019. Throughout the gardening period, the concentration of Pb and Cd in the leachates from the remediated soil was lower and that of Zn was higher than in the original soil. Remediation decreased the concentration of plant-available and mobile toxic metals, as determined by CaCl$_2$ and NH$_4$NO$_3$ extractions, and reduced the bioavailability of Pb, Zn, and Cd in the simulated human gastrointestinal phase by an average of 4.3, 1.7 and 2.7-fold, respectively. Revitalization with vermicompost, earthworms and rhizosphere soil, and spring fertilisation with compost and manure, had no significant effect on the mobility and accessibility of the toxic metals. The ReSoil® is a cost-effective technology (material cost = 18.27 € ton$^{−1}$ soil) and showed the prospect of sustainable reuse of remediated soil.

Per- and polyfluoroalkyl substances (PFAS) are ubiquitous in landfill leachate due to their widespread applications in various industrial and consumer products. Yet, there has been no cost-effective technology available for treating PFAS in leachate because of the intrinsic persistency of PFAS and the high matrix strength of landfill leachate. We tested a two-step 'Concentrate-&-Destroy' technology for treating over 14 PFAS from a model landfill leachate through bench- and pilot-scale experiments. The technology was based on an adsorptive photocatalyst (Fe/TNTs@AC), which was able to selectively adsorb PFAS despite the strong matrix effect of the leachate. Moreover, the pre-concentrated PFAS on Fe/TNTs@AC were effectively degraded under UV, which also regenerates the material. The presence of 0.5 M H2O2 during the photocatalytic degradation enhanced the solid-phase destruction of the PFAS. Fresh Fe/TNTs@AC at a dosage of 10 g/L removed >95% of 13 PFAS from the leachate, 86% after first regeneration, and 74% when reused three times. Fe/TNTs@AC was less effective for PFBA and PFPeA partially due to the transformation of precursors and/or longer-chain homologues into these short-chain PFAS. Pilot-scale tests preliminarily confirmed the bench-scale results. Despite the strong interference from additional suspended solids, Fe/TNTs@AC removed >92% of 18 PFAS in 8 h under the field conditions, and when the PFAS-laden solids were subjected to the UV-H2O2 system, ~84% of 16 PFAS in the solid phase were degraded. The 'Concentrate-&-Destroy' strategy appears promising for more cost-effective removal and degradation of PFAS in landfill leachate or PFAS-laden high-strength wastewaters.

Materials of nano-dimensions are gaining popularity due to their inherent properties such as high reactivity, mobility and surface area. Environmental bioremediation by employing microbial platforms is one of the most rapidly growing areas of nano-biotechnology. Nanoparticles synthesized using biological entities such as yeast, bacteria, fungi, algae and plants are referred to as biogenic nanoparticles. Owing to their nontoxicity, biologically synthesized nanoparticles have emerged as a sustainable alternative to chemically synthesized nanoparticles. In the past few years, several biogenic nanoparticles have been developed for potential application in medicine and environmental remediation. Biogenic nanoparticles such as biogenic manganese oxide (BioMnOx), biogenic nano-magnets, bio-palladium nanocrystals and biogenic iron species have proven to be effective for the removal of several micro-pollutants, heavy metals, recalcitrant pollutants and halogenated compounds. Nano-bioremediation could emerge as a better, safer, ecofriendly and cost-effective technology, which can greatly influence the domain of environmental remediation in the long run. This study reviews the synthesis, classification and applications of microbial nanoparticles for environmental bioremediation.

Composting is an efficient and cost-effective technology for sewage sludge treatment, and bulking agents are essential in sewage sludge composting. In this study, perlite was chosen as inorganic bulking agent to partially substitute for the organic bulking agent. Variations in the temperature, bulk density, moisture content, pH, electrical conductivity, organic carbon, nitrogen, phosphorus and potassium were detected during sewage sludge composting. The treatment with a mass ratio of spent mushroom substrate to perlite at 3:1 exhibited the highest pile temperature and the best effect on reducing bulk density and moisture content. In addition, Fourier transform infrared spectra showed that perlite promotes the degradation of organic matter during the composting process, and the germination index showed that the compost from all treatments was safe for agricultural application. When the mass ratios of spent mushroom substrate and perlite at 3:1 and 2:2 were chosen as bulking agents, the sewage sludge compost product could be used to produce plant cultivation substrate, and economic benefits could be obtained from sewage sludge composting according to comprehensive cost analysis.

The photocatalytic selective transformation of amines is a green and cost-effective technology to obtain value-added products in chemical industry. In this work, a series of bismuth-based photocatalysts including Bi2MoO6, Bi2WO6, Bi5O7Cl, Bi5O7Br, Bi5O7I, BiPO4, BiVO4, Bi2O3 and various morphology Bi2O2CO3 (flower-like, sponge-like, plate-like and spherical) were synthesized and employed in the aerobic oxidative coupling of benzylamine. It is found that flower-like Bi2O2CO3 exhibited the highest photocatalytic activity, in which a 100% conversion of benzylamine with 99.0% selectivity of N-benzylidenebenzylamine was obtained at room temperature. Moreover, the photocatalytic oxidative coupling processes of various aromatic and aliphatic amines were further investigated, and excellent yields and selectivities of corresponding products are attained. Then, based on characterization results (XRD, SEM, BET and XPS, etc.) of catalyst, high photocatalytic activity of flower-like Bi2O2CO3 is attributed to thin nanopetals, low band gap, the morphology and large specific surface area. Finally, a possible reaction mechanism is proposed for the photocatalytic oxidative coupling of benzyl amine.

Polyphenol compounds from vine pruning residue (VPR) were extracted by conventional heating and microwave-assisted treatments. For each treatment, total phenolic compounds and their antioxidant activity were optimized by experimental design. Maximal extraction of polyphenolic compounds (2.17g/100g VPR) was obtained at 80°C, 120min and 45% of ethanol by conventional heating, and 2.37g/100g of VPR were extracted by microwave-assisted process at 120°C, 5min and 60% of ethanol. Ellagic acid and apigenin were the predominant polyphenolic compounds in the extracts, achieving concentration of 68.65 and 208.23mg/100g VPR, respectively for conventional heating and 185.15 and 118.84mg/100g of VPR for microwave-assisted treatment. The results showed reduction of extraction time and energy consumption for microwave-assisted treatment leading to cost-effective technology for the extraction of polyphenol compounds. Furthermore, the results hereby compiled allow for the tailor-made extraction of specific high-value compounds from a renewable biomass as vine pruning residue., Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2019 unit, BioTecNorte operation(NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte, International Cooperation Program CNPq/CSF, info:eu-repo/semantics/publishedVersion

Constructed wetland is a low cost, effective technology and it is still in the state of improvement to enhance the treatment efficiency, especially in nutrient and trace elements treatment. This study investigated the effect of aerobic and anoxic conditions in Horizontal Subsurface Flow Constructed Wetland (HSFCW) on nutrient, organic, metal and Octylphenol - OP (Endocrine disrupting chemical) treatment. Two HSFCWs were constructed: HSFCW1 with three aerobic compartments; HSFCW2 with two aerobic compartments, one anoxic compartment. The two HSFCWs had the same design parameters (fiters, plants), except oxygen conditions. The results showed that aerobic and anoxic HSFCW may increase the efficiency of Nitrogen removal by 10%, but decreased by 11% in the efficiency of OP treatment (one of the EDCs). The efficiency of treatment of pollutants, including NH4+-N, COD, TP, Mn, Fe, Al and Cu between two HSFCWs were not significantly different; the average efficiency was 99%, 84%, 97%, 96%, 96%, 72% and 73%, respectively. Therefore, the anoxic compartment of HSFCW still provided the effective removal of organic matter, Manuscript received September 29th, 2017; accepted 24th December, 2017 This study was funded by CARE RESCIF under grant number Tc-TTC-2017-05. An Truong Nguyen, Tam Minh Thi Le, Viet Quoc Tran, Trang Huyen Thi Nguyen are with the CARE, Ho Chi Minh City University of Technology, VNU-HCM, Vietnam (truongan.hcmut@gmail.com, minhtamnt2006@hcmut.edu.vn, ngthtrang@hcmut.edu.vn) Viet Ngoc Truong, Luan Thanh Nguyen, Phi Hoang Tan Nguyen are with the Faculty of Environment and Natural Resources, Ho Chi Minh City University of Technology, VNU- HCM, Vietnam (truongngocviet93@gmail.com) metals and octylphenol, but it also improved nitrogen removal efficiency by up to 92%.

Ion foam fractionation is a green and cost-effective technology where separation of molecules exploits the difference in surface affinity. In this work, a batch ion foam fractionation system was designed and optimized for the separation of trace hexavalent chromium (Cr(VI)) from aqueous solutions. The effect of surfactant head groups (collectors) on the adsorption dynamics was analyzed. Cetyl trimethyl ammonium bromide (CTAB), a cationic surfactant showed high efficiency for the removal of Cr(VI) from aqueous solutions. An experimental investigation of the effect of different operational parameters on the separation characteristics is presented. The recovery of Cr(VI) increased with the increase in CTAB/Cr(VI) molar ratio and reached a maximum of 92.5% at optimum operating conditions. However, with CTAB concentrations close to the critical micelle concentration (CMC) wet foams were produced resulting in high liquid hold-up and poor enrichment ratio. The presence of Cr(VI) at the gas-liquid interface significantly improved the drainage characteristics of the foam decreasing the liquid hold-up. Further, a three-stage ion foam fractionation unit was developed with Cr(VI) removal efficiency of more than 99%. The concentration of Cr(VI) in the residue after the three-stage operation was less than 0.02 mg/L which is below the USEPA recommended standards for drinking water.

Biodegradation was regarded an environmentally benign and cost-effective technology for formaldehyde (CH2 O) removal. However, the biotoxicity of CH2 O inhibited microbial activity and decreased removal performance. We developed a novel heterotopic CH2 O biodegradation process that combined bioelectrochemical system (BES) and UV/H2 O2 . Instead of exogenous addition, H2 O2 was biosynthesized with electron transferred from electrochemically active bacteria. Heterotopic biodegradation of CH2 O was more efficient and faster than in situ biodegradation, as confirmed by 69%-308% higher removal efficiency and 98% shorter degradation time. Operated under optimal conditions for 30 min, which are optical distance of 2 cm, initial H2 O2 concentration of 102 mg/L, and pH 3, heterotopic biodegradation removed 78%, 73%, 49%, and 30% of CH2 O with 6, 8, 10, and 20 mg/L initial concentration. Mild formation of hydroxyl radicals from UV/H2 O2 is beneficial to sustainable CH2 O degradation and efficient H2 O2 utilization. Heterotopic biodegradation is a promising technology for efficient degradation of other organic compounds with biological toxicity. PRACTITIONER POINTS: H2 O2 biosynthesis through electrochemically active bacteria (EAB) served as source of ·OH for CH2 O removal in UV/H2 O2 . Heterotopic CH2 O biodegradation avoided the biotoxicity of CH2 O. Heterotopic biodegradation of CH2 O saved 98% time than in-situ biodegradation. Heterotopic CH2 O biodegradation improved 69%-308% efficiency than in-situ.

An integrated process of cellulase production and pretreatment employing Piptoporus betulinus was proposed to accomplish economic feasibility of lignocellulosic ethanol. After 24 days of cultivation, the maximum loss of weight and hemicellulose of rice straw was 21.25% and 24.79%, respectively. The cellulose was degraded slightly and exposed. Furthermore, the modified lignin led to the weak interaction between lignin and hemicellulose. The optimized enzyme production for CMCase activity (58.37 U g−1 substrate) and FPase activity (7.43 U g−1 substrate) were obtained on the 12th day and the 18th day, respectively. Whereas, the highest reducing sugar yield of rice straw (392.96 mg g−1) was obtained on the 24th day, which was 2.82 times higher than that of the control with the reduced cellulase dosage of 37.15%. In this study pretreatment, cellulase production and enzymatic hydrolysis were coupled into one process, which opens an avenue for environmentally friendly and cost effective technology in lignocellulosic ethanol production.

Triboelectric nanogenerator (TENG) is a new emerging and cost-effective technology for harvesting water wave energy because of its unmatchable performance in low frequency and randomly directed motions. Here, we report an approach that significantly increased the output power of spherical TENGs by optimizing both materials and structural design. Fabricated with an acrylic hollow sphere as its shell and a rolling flexible liquid/silicone as the soft core, the soft-contact spherical triboelectric nanogenerator (SS-TENG) presents up to 10-fold enhancement to the maximum output charge compared to that of a conventional Polytetrafluoroethylene (PTFE) based hard-contact one, which is resulted from the significantly increased contact area. Besides, the output is tunable through controlling the softness of the liquid/silicone core. Our finding provides a new optimization methodology for TENGs and enable its more promising usage in harvesting large-scale blue energy from water wave in oceans as well as feeble but ubiquitous wind energy.

In the present investigation, several residues from agro-forestry industries such as rice straw acid hydrolysate, corn cob acid hydrolysate, tomato juice, cane molasses and orange pulp were evaluated as the economical source for the production of bacterial cellulose. The bacterial cellulose attained the significant yield of 7.8 g/L using tomato juice, followed by 3.6 g/L using cane molasses and 2.8 g/L using orange pulp after 7 days of incubation. Furthermore, the optimum pH and temperature of fermentation for maximum production of bacterial cellulose was 4.5 and 30 ± 1 °C. The identified bacterium Acetobacter pasteurianus RSV-4 has been deposited at repository under the accession number MTCC 25117. The produced bacterial cellulose was characterized through FTIR, SEM, TGA and DSC and found to be of very good quality. The bacterial cellulose produced by identified strain on these various agro-waste residues could be a cost effective technology for commercial its production.

In this work, a simple electrical conductivity measurement technique is applied to effectively determine the boron concentration in the aqueous solution based on the ionized complex formed between boron species and vitamin B6, which can be easily detected and accurately measured using a conductivity meter. The log of boron concentration is linearly correlated with the log of conductivity change within the range of 0–550 mg/L boron content. The correlation coefficient (R2) is up to 0.99882. The reproducibility is 100%. The methods can be directly applicable in deionization water or diluted seawater within diluted factor 34 times or higher (0–1600 us/cm conductivity range). This work provides a cost-effective technology for the boron measurement and will be of great industrial importance in boron measurement field.

The oxidation of As(III) to As(V) is a critical process in the treatment of contaminated water. We found that 95% As(III) (10 mg L−1) could be rapidly oxidized to As(V) by a laccase–2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) system in 1 h. Based on this finding, we used Bacillus subtilis spores instead of laccase for As(III) oxidation with the same effect because the former had plenty of CotA–laccase on their surface. The catalytic ability of CotA protein and spores was confirmed by expressing the CotA protein and knocking out the cotA gene from wild-type spores. Both laccase– and spore–TEMPO systems displayed similar oxidation rate constants, Michaelis–Menten constants, and maximal velocities owing to the formation of the oxoammonium cation of TEMPO in the presence of dissolved oxygen. Several other laccase mediators such as 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic-acid) (ABTS), acetosyringone (AS), 1-hydroxybenzotriazole (HBT), 2-hydroxybutyl acrylate (HBA), violuric acid (VLA), 4-oxo-TEMPO, 4-amino-TEMPO, 4-methoxy-TEMPO, 4-hydroxy-TEMPO benzoate, and 4-hydroxy-TEMPO coupled with spores for As(III) oxidation were also investigated in detail. The spore–TEMPO system exhibited the highest oxidation efficiency and tolerated the addition of 10 mg L−1 Al3+, Ti4+, Cu2+, K+, Fe3+, Zn2+, Ni2+, Mg2+, Co2+, and Mn2+. Both laccase and spores recovered via ultrafiltration and centrifugation, respectively, could be reused for at least five cycles. The developed spore-based system has several advantages including eco-friendliness, ease of operation and storage, low cost, recyclability, sustainability, and without the need for enzyme purification. These findings may have promising implications for developing a new eco-friendly and cost-effective technology for the treatment of arsenic-containing water.

Humic substances (HSs) are a group of complex macromolecular polymeric compounds originating from the decomposition of plant residuals and other organic matter. Within the presence of micro-pollutants and heavy metals, HSs negatively act upon potable water quality by contributing to aesthetic problems such as yellowish or brownish color and annoying taste and odor. They are also responsible for re-growth of pathogenic microorganisms and fouling of membranes in water distribution systems. More importantly, these high-molecular-weight polymers have been noted to be the major contributor to the formation of disinfection by-products (DBPs) such as trihalomethanes (THMs) and haloacetic acids (HAAs). Considering these harmful effects, removal of HSs is one of the significant tasks in drinking water treatment. For this purpose, this study aimed to explore the effects of various operating parameters (initial concentration, initial pH, electrical conductivity, pulse time, pulse number, and process time) on the humic acid (HA) removal efficiency and energy consumption. In this study, a new current supply method called alternating pulse current electrocoagulation-flotation (APC-ECF) process was proposed, and a detailed comparative optimization of four different ECF processes (direct current (DC)-simple electrode, DC-perforated electrode, pulse current-simple electrode, and pulse current-perforated electrode) was conducted within the framework of Taguchi-based experimental design methodology. According to scanning electron microscopy (SEM), the morphology of electrode surfaces with APC and perforated electrode showed less disordered (irregular) pores and a regular structure of aluminum compared to the DC, which confirmed the difference in the corrosion rates. Moreover, the proposed APC-ECF method led to the production of less dewatered and dense sludge. The results of the performance analysis revealed that the APC with a perforated electrode provided 3.2-fold lower energy consumption and 2.5-fold lower aluminum consumption compared to the DC with a simple electrode. Considering the expenses associated with power consumption and sludge disposal costs for the electrocoagulation unit, the experimental findings corroborated that the proposed APC-ECF process could be used as a promising and cost-effective technology in water treatment for the removal of HSs.

Resveratrol (2,5,4′-trihydroxystilbene) is a naturally occurring phytoalexin produced by some spermatogphytes and it has recently attracted the increasing attention of agronomists and pharmacologists owing to its satisfactory bioactivities. The objective of this work was to develop a cost-effective technology of foam fractionation to recover trans-resveratrol (trans-Res) from the leaching solution of muscat grape pomace on the assistance of molecular imprinting modified SiO2 nanoparticles. First, trans-Res was leached from muscat grape pomace through the method of alkaline extraction. Under the suitable leaching conditions, the leaching yield of trans-Res reached 84.34%. Adsorption experiments were performed for describing the adsorption behavior of trans-Res on the molecular imprinting modified SiO2 nanoparticles. Results indicated that their adsorption could be fairly described by Freundlich model and fitted well with the pseudo-second-order kinetics model. Moreover, the molecular imprinting modified SiO2 nanoparticles could effectively maintain the stability of trans-Res through avoiding the cis-trans photo-isomerization and oxidative degradation. Finally, foam fractionation was carried out for recovering trans-Res from the leaching solution, in which the concentration of trans-Res was as high as 29.09 mg/L. The molecular imprinting modified SiO2 nanoparticles were used as the collector. Under the suitable conditions of loading liquid volume 250 mL, particle size of molecular imprinting modified SiO2 nanoparticles 436.0 nm, sapindus saponin concentration 0.075 g/L, volumetric gas flow rate 100 mL/min and pore diameter of gas distributor 0.180 mm, the enrichment ratio and the recovery percentage of trans-Res reached 13.68 ± 1.03 and 89.73 ± 3.57%, respectively. This work is expected to provide a new technology for selectively recovering non-surface-active materials from the solution with their isomers or analogues, and to facilitate the industrialization of foam fractionation.

Human pluripotent stem cell derived endothelial cells (hPSC-ECs) are of great value for studying and treating vascular diseases. However, manufacturing high quantity and quality hPSC-ECs with current cell culture technologies remains very challenging. Here, we report a novel method that can manufacture hPSC-ECs in scalable and cell-friendly microenvironments to address this challenge. Using this method, hPSCs are expanded and differentiated into ECs in microscale alginate hydrogel tubes. The hydrogel tubes protect cells from the highly variable hydrodynamic conditions and critical hydrodynamic stresses in the culture vessel and limit the cell mass less than the diffusion limits (of human tissue) to ensure efficient mass transport. The hydrogel tubes provide uniform and friendly microenvironments for cells to grow. This novel design leads to extremely high production efficiency. We showed that hPSC-ECs could be produced in 10 days with high viability (>90%), high purity (>80%) and high yield (∼5.0 × 108 cells per mL of microspace). The yield is about 250 times that of the current-state-of-the-art. hPSC-ECs made in these hydrogel tubes had similar in vitro and in vivo functions to hPSC-ECs generated by conventional cell culture methods. This simple, scalable, efficient, defined and cost-effective technology will make hPSC-ECs broadly available and affordable for various biomedical applications.

In recent years, capacitive deionization (CDI) has emerged as an energy efficient and cost-effective technology for the desalination of brackish water. However, high energy consumption and poor desalting efficiency at high salinity levels have hampered the application of CDI for seawater (∼35 000 mg L-1). A novel method of CDI termed hybrid capacitive deionization (HCDI) employs the use of a faradaic electrode paired with a capacitive electrode. Doing so increases the salt removal capacity to approximately three times that of conventional activated carbon (AC) materials (∼10 mg g-1). Herein, we report experimental results of our HCDI cell using free-standing Na2Ti3O7-CNT@reduced graphene oxide (NCNT@rGO) film as a binder-free negative and activated carbon@reduced graphene oxide (AC@rGO) film as the positive electrode. The HCDI cell is operated under a constant current mode. During desalination, sodium ions are intercalated into the negative electrode (NCNT@rGO) whereas chloride ions are adsorbed onto the surface of the positive electrode (AC@rGO). We observed a high removal capacity of 129 mg g-1 at the low energy consumption of 0.4 W h g-1 for a salt concentration of ∼3000 mg L-1 at 50 ml min-1 flow rate. The higher performance of our electrodes over conventional ones (∼109 mg g-1, 0.68 W h g-1) is attributed to the absence of binders or conductive additives and the unique nano-architectured sandwich structure of NCNT@rGO. The advantageous features of our electrodes shed new insight into the development of CDI materials and show promise for low-cost, scalable systems.

Phytoremediation is a potential cost-effective technology for remediating heavy metal-contaminated soils. This method was used to evaluate the biomass and accumulation of copper (Cu) and cadmium (Cd) of plant species grown in contaminated soil and their biological and physical effects on the soil. In co-contaminated soils with copper (Cu) and cadmium (Cd), a three-year field experiment was conducted by planting four plant species in the co-contaminated acidic soil treated with hydroxyapatite. The four species produced different amounts of biomass in this order: Pennisetum sp. > Elsholtzia splendens > Setaria lutescens > Sedum plumbizincicola. Over three growing seasons, the best accumulators of Cu and Cd were Elsholtzia splendens and Sedum plumbizincicola, respectively. Overall, Pennisetum sp. was the best species for Cu and Cd removal when biomass was considered. The four plant treatments could improve the content of >0.25 mm mechanically stable (DR0.25) and water-stable (WR0.25) aggregates and significantly improve the aggregate mean mass diameter (MWD) and the geometric mean diameter (GMD). The largest increase was with the treatment of Pennisetum sinese, while the fractal dimension (FD) of mechanically stable aggregates could be significantly reduced by the treatment of Pennisetum sp. Hydroxyapatite and phytoremediation could improve the soil enzyme activity, and Elsholtzia splendens had the best effect in this respect. This study will provide a better understanding of the remediation of heavy metal contaminated soil.