Removal Of Contaminants In Water Research Articles

Development of Adsorptive Membranes for Selective Removal of Contaminants in Water.

The presence of arsenic and ammonia in ground and surface waters has resulted in severe adverse effects to human health and the environment. Removal technologies for these contaminants include adsorption and membrane processes. However, materials with high selectivity and pressure stability still need to be developed. In this work, adsorbents and adsorptive membranes were prepared using nanostructured graphitic carbon nitride decorated with molecularly imprinted acrylate polymers templated for arsenate and ammonia. The developed adsorbent removed arsenate at a capacity and selectivity similar to commercial ion-exchange resins. Ammonia was removed at higher capacity than commercial ion exchange resins, but the adsorbent showed lower selectivity. Additionally, the prepared membranes removed more arsenate and ammonia than non-imprinted controls, even in competition with abundant ions in water. Further optimization is required to improve pressure stability and selectivity.

Vanadium trioxide mediated peroxymonosulfate for fast metronidazole oxidation: Stepwise oxidation of vanadium for donating electrons

In this study, vanadium trioxide (V2O3) was adopted to activate PMS via a Fenton-like reaction to degrade metronidazole (MNZ). The V2O3-PMS system can almost completely degrade MNZ at 30 min with 42.4% TOC removal. Comparative tests reveal that V2O3 stands out among a variety of heterogeneous catalysts, including metallic oxides and carbon materials. Sulfate radicals (SO4•−) and hydroxyl radicals (•OH) derived from PMS decomposition are major reactive oxygen species, based on quenching tests, electron spin resonance (ESR) analysis, the steady-state concentrations of radicals ([SO4•−]ss = 5.1 × 10-13 M and [•OH]ss = 4.0 × 10-14 M), and kinetics model. The process of stepwise electron transfer from vanadium species to PMS to produce reactive radicals was proved by small-molecule simulation experiments and pickling experiments of vanadium oxides. Possible pathways of MNZ degradation were proposed based on the results of LC-MS and Fukui function, including two stages of the hydroxylation and bond cleavage of nitro and the subsequent ring-opening. This study reveals the high reusability and practicability of the V2O3-PMS system over a relatively wide pH range, which puts forward a new vision on V2O3 induced Fenton-like reactions and a new reference method for the removal of medical organic contaminants in water.

Chitosan-modified geopolymer sub-microparticles reinforced multifunctional membrane for enhanced removal of multiple contaminants in water

Nanoparticle-reinforced membranes have received widespread interest in water purification; however, their application is limited due to high cost, harsh conditions, and strong tendency of nanoparticles agglomeration and leaching. Herein, a multifunctional membrane was newly created by filling the pores of a glass fiber microfiltration membrane (GF) with chitosan-modified geopolymer sub-microparticles (CS-GMs) and crosslinking with polydopamine. Characterizations revealed that the introduction of CS-GMs was successful in regulating the porous structure of the membrane and suppressing membrane thickness growth and particle agglomeration. With an optimal dose of CS-GMs (0.45 g), the screening pore size of the membrane was regulated to 58 nm, thus showing a high rejection rate for microplastics (89.37%). In addition, the membrane was super-hydrophilic/underwater super-oleophobic and superior to the documented nanoparticle-reinforced membranes in decontaminating different oil-in-water emulsions (>99.5%) and co-existing pollutants (n-hexadecane: 99.62%, crystal violet: 94.51%, and lead ions: 99.62%) due to the effects of sieving and adsorption. Moreover, it possessed good reusability, rational environmental tolerance, long-term operational stability and point-of-use functions. Overall, this study paves the way for the feasible creation of low-cost, eco-friendly, and multifunctional sub-microparticle-reinforced membranes for the effective elimination of multiple contaminants in wastewater.

Enhanced photo-Fenton degradation of fluoroquinolones in water assisted by a 3D composite sponge complexed with a S-scheme MoS2/Bi2S3/BiVO4 ternary photocatalyst

A constructed MoS2/Bi2S3/BiVO4 ternary photocatalyst(MBB) mainly with a S-scheme heterostructure was loaded on a 3D lignosulfonate modified poly(vinyl formal) sponge to obtain a novel composite sponge(PLS-MBB) with an enhanced performance in synergistic adsorption and photo-Fenton degradation of various fluoroquinolones(FQs) in water. The synergistic adsorption and photocatalysis of PLS-MBB notably improved the applicable pH from 2.0 to 9.0 and reduced the dosage of Fe2+ to 0.014 mmol/L in Fenton reaction, which could achieve the degradation efficiency of 92.8 % for FQs within 60.0 min at pH 6.0. The photo-generated electrons by MBB and the redox transformation of Mo(IV)/Mo(VI) and Bi(III)/Bi(V) accelerated the conversion of Fe3+ to Fe2+; besides, the efficient adsorption of FQs on the sponge carrier promoted the surface degradation in solution, thereby causing an enhanced photo-Fenton reaction. This work provided a novel strategy to improve photo-Fenton reaction and accordingly fabricated a talented material for effective removal of organic contaminants in water.

Few-layered Bi4O5I2 nanosheets enclosed by {1 0−1} facets with oxygen vacancies for highly-efficient removal of water contaminants

Few-layered Bi4O5I2 nanosheets (FL-Bi4O5I2) were synthesized by intergrowth with Bi2O2CO3 under room temperature. The photoactivity of FL-Bi4O5I2 was 2.5 and 9.5 times higher than that of Bi4O5I2 nanoflakes (NF-Bi4O5I2, about 30 nm thickness) and standard visible-light-driven N-TiO2, respectively. Moreover, FL-Bi4O5I2 exhibited a wide pH application range (3.0 – 10.0) and excellent photostability. The characterization results showed FL-Bi4O5I2 was consisted of 5 – 8 layers with thickness of 4 – 7 nm and enclosed by {1 0 − 1} facets. The ultrathin characteristics could accelerate the charge transfer to the surface due to the shortened transport distance. Compared to NF-Bi4O5I2, surface oxygen vacancies and the more negative CB potential were formed on FL-Bi4O5I2. The photogenerated electrons were confirmed to be captured by surface oxygen vacancies to effectively reduce surface adsorbed O2 into HO2•/O2•–, leaving more h+ to oxidize organic pollutants. This process was further facilitated by the more negative CB potential of FL-Bi4O5I2, resulting in the highly efficient removal of pollutants.

Promise of nonthermal plasmas in addressing emerging environmental and health problems: Present and future

Nonthermal atmospheric pressure plasmas transform input electrical energy efficiently into reactive species, charged particles, and photons. This “activated gas” is being investigated as solutions for a range of environmental and health problems facing society today. In this Perspective, we take a cursory look at a few of these societal problems and the reflected role that plasmas may play in charting the pathway to a solution buoyed by supporting research. Here, we survey the plasma-based opportunities in the removal of trace contaminants in water supporting methodologies such as water reuse, which addresses scarcity and pollution, the opportunity posed by plasmas-based chemical depolymerization for plastics recycling, and the application of plasmas for food security, which includes sterilization of foodstuffs and the improvement of crop yield. Finally, we also included a short review on how plasmas may help control disease spread. In each case, the scope of the problem is presented along with the potential plasma-based solution.

Novel data-driven energy management of a hybrid photovoltaic-reverse osmosis desalination system using deep reinforcement learning

This paper proposes a novel deep reinforcement learning-accelerated energy management system for a hybrid grid-connected photovoltaic-reverse osmosis-pressure retarded osmosis desalination plant. The energy management problem is formulated as a partially observable Markov decision process by using historical photovoltaic (PV) power data in order to cope with uncertainties related to the generation of solar power and provide more information regarding the true state of the system. The soft actor-critic (SAC) algorithm is employed as the core of the energy management system to maximize water production rate and contaminant removal efficiency while minimizing the supplied power from the external grid. We introduce 1-dimensional convolutional neural networks (1-D CNNs) to the actor, critic, and value function networks of the SAC algorithm to address the partial observability dilemma involved in PV-powered energy systems, extract essential features from the PV power time series, and achieve immensely improved performance ultimately. Furthermore, it is assumed that the proposed CNN-SAC algorithm does not have access to the current output power data of the PV system. The development of more practical energy management systems necessitates this assumption, and we demonstrate that the proposed method is capable of forecasting the current PV power data. The superiority of the CNN-SAC model is verified by comparing its learning performance and simulation results with those of four state-of-the-art deep reinforcement learning algorithms: Deep deterministic policy gradient (DDPG), proximal policy optimization (PPO), twin delayed DDPG (TD3), and vanilla SAC. The results show that the CNN-SAC model outperforms the benchmark methods in terms of effective solar energy exploitation and power scheduling, manifesting the necessity of exploiting historical PV power data and 1-D CNNs. Moreover, the CNN-SAC algorithm is benchmarked against a powerful energy management system we developed in our previous investigation by studying three scenarios, and it is demonstrated that considerable improvement in energy efficiency can be obtained without using any solar power generation forecasting algorithm. By conducting ablation studies, the critical contribution of the introduced 1-D CNN is demonstrated, and we highlight the significance of providing historical PV power data for substantial performance enhancement. The average and standard deviation of evaluation scores obtained during the last stages of training reveal that the 1-D CNN significantly improves the final performance and stability of the SAC algorithm. These results demonstrate that the modifications we detail in our investigation render deep reinforcement learning algorithms extremely powerful for the energy management of PV-powered microgrids, including PV-driven reverse osmosis desalination plants.

Constructing benzene ring modified graphitic carbon nitride with narrowed bandgap and enhanced molecular oxygen activation for efficient photocatalytic degradation of oxytetracycline

Popular graphitic carbon nitride (g-C3N4) photocatalyst always faces the problems of weak visible light absorption and fast recombination of photogenerated electron-hole pairs. Herein, a novel benzene ring modified g-C3N4 nanosheet (BCNNS) was synthesized by a simple calcination method. The degradation rate of oxytetracycline by BCNNS under visible light can reach 72% (within 60 min), significantly higher than that of the unmodified g-C3N4 nanosheet (50%). And the degradation rate constant of BCNNS is 0.025 min−1, which is 2.1 times higher than that of g-C3N4 (0.012 min−1). The improvement in the photocatalytic degradation performance can be attributed to the introduction of benzene ring, which can significantly broaden the light absorption range and intensify. In addition, the introduction of benzene ring can adjust the original electronic structure, thereby effectively suppressing the recombination of electron-hole pairs. Furthermore, density functional theory (DFT) calculations demonstrate that the introduction of benzene ring can significantly promote the surface adsorption of molecular oxygen and promote the transfer of electrons to molecular oxygen. This demonstrates that the embedded benzene ring can effectually advance the activation of molecular oxygen, which also well confirms that O2− and 1O2 are the main active species in the system of BCNNS photocatalytic degradation of oxytetracycline. This study reveals that benzene ring modified g-C3N4 has great potential in environmental purification, and provides a promising strategy for the removal of stubborn water contaminants.

TiO2–SnO2 Nanocomposites for Photocatalytic Environmental Remediation under UV-Light

The photocatalytic removal of water contaminants for ecological systems has become essential in the past few decades. Consequently, for commercialization, cost-efficient, earth-abundant and easy to synthesize photocatalysts for dye degradation are of urgent need. We have demonstrated a simple and feasible approach for fabricating TiO2–SnO2 nanocomposite photocatalysts via urea-assisted-thermal-decomposition with different mass ratios. The as-synthesized materials were characterized by different physicochemical techniques. The phase formation and crystallite size were calculated by using XRD. The STEM, UV-Vis, DRS, HR-TEM and EDS revealed the effective formation of the heterojunction between TiO2 and SnO2, and enrichment in the UV-absorption spectrum. All synthesized materials were used for the photocatalytic degradation of methyl orange (MO) under UV light. The optimized results of the TiO2–SnO2 nanocomposite showed excellent photostability and photocatalytic activity over a number of degradation-reaction cycles of methyl-orange (MO) dye under the illumination of ultraviolet light. In addition, the recent method has great potential to be applied as a proficient method for mixed-metal-oxide-nanocomposite synthesis.

Electrospun Cellulose-Acetate/Chitosan Fibers for Humic-Acid Removal: Improved Efficiency and Robustness with a Core-Sheath Design.

Recycling biomass waste into functional materials has attracted much attention, and a rational structural design can make more effective use of each component. In our previous work, the fabrication of electrospun cellulose-acetate (CA)/chitosan (CS) adsorbents for humic-acid (HA) removal guided by the intermolecular interaction mechanism was demonstrated. Herein, a core-sheath structure was designed via one-step co-axial electrospinning, where a mixture of CS and CA was employed as the sheath layer to efficiently adsorb HA, and cellulose nanocrystals (CNCs) derived from waste cotton fabrics were incorporated into the CA core as load-bearing components. Compared to the non-layered electrospun CS/CA fibers, all the CS/CA–CNC fibers with a core-sheath structure exhibited smaller diameters, greater homogeneity, and significantly improved mechanical strength. Meanwhile, their maximum adsorption capacities towards HA had no significant differences. Even after the complete hydrolysis of CA into cellulose, the electrospun fibers maintained the fibrous structures and showed a higher tensile strength while exhibiting an acceptable adsorption capacity towards HA. Therefore, this work demonstrates the importance of rational design in the efficient preparation of functional materials and the feasibility of using electrospun core-sheath fibers derived from biomass wastes for the removal of water contaminants.

Heterogeneous Photocatalytic Activation of Persulfate for the Removal of Organic Contaminants in Water: A Critical Review

Heterogeneous Photocatalytic Activation of Persulfate for the Removal of Organic Contaminants in Water: A Critical Review

Photodegradation and in‐Situ SERS Monitoring Properties of Ag@AgCl Anchored on Sea Urchin‐shaped Fe3O4@C/1D PANI Nanoparticles**

AbstractHere, sea urchin‐shaped nanoparticles were first fabricated by growing one dimensional polyaniline (1D PANI) nanowire array on carbon layer encapsulated Fe3O4 nanoparticles, and then Ag@AgCl photocatalyst were tightly anchored on the surface of PANI nanowire to form Fe3O4@C/1D PANI/Ag@AgCl bifunctional material as recyclable adsorption‐photocatalysts and surface enhanced Raman scattering (SERS) substrate to monitor photocatalytic degradation of dye molecules. Compared with Fe3O4@C/1D PANI, Ag@AgCl and Fe3O4@C/PANI/Ag@AgCl catalysts, the fast electron transfer characteristics of conductive 1D PANI nanowire array and the synergistic effect between the surface plasmon resonance of Ag and the photosensitive characteristic of AgCl, enabled the prepared Fe3O4@C/1D PANI/Ag@AgCl excellent adsorption‐photocatalytic efficiency for the degradation of RhB under visible‐light irradiation. PL spectra and a series of photoelectrochemical measurements were carried out to investigate the reasons for such enhanced photocatalytic activity and the possible improved photocatalytic degradation mechanism was proposed. Meanwhile, the detection of the presence of RhB and its degradation process were achieved with real‐time SERS technology employing the prepared Fe3O4@C/1D PANI/Ag@AgCl photocatalyst itself as the substrate. All the results made it great promise for simultaneously monitoring and removal of organic contaminants in water.

Chitosan immobilised granular FeOOH-MnxOy bimetal-oxides nanocomposite for the adsorptive removal of lead from water

Mixed metal-oxides are an important class of materials studied for the adsorptive removal of contaminants in water. However, the lack of affordable and versatile immobilisation techniques limits its large-scale deployment in water purification. The present work describes the use of protonated chitosan as a template and reinforcing agent to fabricate FeOOH-MnxOy bimetal-oxide granules formed via complexation of metal-oxides with hydroxyl and amine groups in chitosan. The synthesis procedure also enables the modulation of nanocomposite into granules of different shapes and sizes. XRD and XPS analyses confirm the existence of MnO, Mn2O3, MnO2, and FeOOH phases in the composite. The granules showed excellent affinity to scavenge the model pollutant, Pb2+, through inner-sphere complexation with an estimated Sips isotherm capacity of 108.12 mg/g. The chemical stability analysis of the composite showed that the leaching of Fe and Mn from the composite is pH, contact time, and temperature dependent. The background ions can also affect the chemical stability of the composite. However, Fe and Mn leaching were well within the permissible limit under typical groundwater pH and temperature. There is no significant effect on Pb2+ intake by competing ions such as Cl-, NO3-, HCO3-, Ca2+, Fe2+, and Mn2+. In short, the improved adsorption capacity, the ability to form hydraulically stable granules, and ease of synthesis make the composite a practical adsorbent for removing heavy metal ions in water.

In silico assessment of household level closed water cycles: Towards extreme decentralization

Water management in most of the developed world is currently practiced in a highly centralized manner, leading to major infrastructure and energy costs to transport water. To decrease the impacts of water scarcity and climate change, the decentralization of water can increase local robustness. In extremis, decentralization can involve building or house level water supply and treatment. Here, we constructed a MATLAB/Simulink model for two decentralized water management configurations at the household level, assuming the socio-environmental setting of Flanders, Belgium. Independence from the potable water grid and sewer system was pursued through rainwater harvesting, reuse of wastewater streams fit-for-purpose, and discharge via infiltration. The mass balance for water was calculated over the system boundaries showing high potential for independence from the grid with a reasonable treatment train and storage options. Next, the risk of contaminant accumulation within the circular system was assessed, showing a key limitation on decentralized system performance necessitating a system purge. Up to 59% of system rainwater usage was due to the replacement of this purge. Employing treatment units with high (95%) contaminant rejection efficiencies eliminated contaminant accumulation issues. The raw model output was quantitatively assessed by constructing four newly proposed key performance indicators (KPIs), quantifying system independence, circularity, drought tolerance and local water body recharge, which allowed for facilitated system comparison and communication to stakeholders. A sensitivity analysis was performed in which the effect of input parameter variability and uncertainty on system performance was quantified. The sensitivity analysis showed the importance of water recovery and contaminant removal efficiencies of the applied treatment technologies on system performance when contaminant accumulation in the system forms an issue. In systems not severely affected by pollutant accumulation, parameters such as inhabitant number and roof surface had the largest effect. As a whole, this work shows the potential of extreme decentralization of water systems and addresses the obstacle towards implementation formed by the accumulation of contaminants due to system circularity. Additionally, this study provides a framework for operational and technological decision support of decentralized household-scale water systems and, by extension, for future water policy-making.

Highly Efficient Visible Light Active Doped ZnO Photocatalysts for the Treatment of Wastewater Contaminated with Dyes and Pathogens of Emerging Concern.

Water is obligatory for sustaining life on Earth. About 71% of the Earth’s surface is covered in water. However, only one percent of the total water is drinkable. The presence of contaminants in wastewater, surface water, groundwater, and drinking water is a serious threat to human and environmental health. Their toxic effects and resistance towards conventional water treatment methods have compelled the scientific community to search for an environmentally friendly method that could efficiently degrade toxic contaminants. In this regard, visible light active photocatalysts have proved to be efficient in eliminating a wide variety of water toxins. A plethora of research activities have been carried out and significant amounts of funds are spent on the monitoring and removal of water contaminants, but relatively little attention has been paid to the degradation of persistent water pollutants. In this regard, nanoparticles of doped ZnO are preferred options owing to their low recombination rate and excellent photocatalytic and antimicrobial activity under irradiation of solar light. The current article presents the roles of these nanomaterials for wastewater treatment from pollutants of emerging concern.

Mechanistic insight into the removal of aqueous Cd using an immobilized ZIF-8 and microflora cooperative composite

Biotechnology and metal-organic-frameworks (MOFs) materials have been investigated intensively for the removal of heavy metal from wastewater. However, the cooperative effect of bacteria and MOFs on heavy metal adsorption was less reported. Considering this, this study has screened out microflora with cadmium (Cd) adsorption ability. Furthermore, it was combined with zeolitic imidazolate framework-8 (ZIF-8) to form a ZIF-8 and microflora complex (ZMC). Moreover, ZMC was further immobilized to improve its Cd adsorption effect and reusability. Results revealed that the immobilized ZMC exhibited 99.91% and 78.83% Cd adsorption rate for 20 mg L−1 and 300 mg L−1 Cd, respectively. Meanwhile, the immobilized ZMC maintained a relatively stable adsorption effect under varied external pH. The reaction mechanism was summarized as covalent binding accompanied with a small amount of electrostatic attraction. Microflora could enhance the surface electronegativity of ZIF-8. ZIF-8 could strengthen the response of antioxidant activity of microflora and augmented the affinity of microflora secretions for Cd. This proposed method may provide a new insight for the removal of heavy metal contaminants in water.

Multifunctional hybrid membranes for photocatalytic and adsorptive removal of water contaminants of emerging concern

This work focuses on the combination of multifunctional photocatalytic and adsorbent materials in a unique polymeric membrane. For this purpose, Au/TiO2 and Y2(CO3)3 nanoparticles were immobilised onto a poly (vinylidene fluoride-hexafluoropropylene), (PVDF-HFP) membrane, and the physical-chemical characterisation of these materials was performed, as well as pollutant removal efficiency. An efficient TiO2 functionalisation with gold nanoparticles was achieved, endowing these particles with the capability to absorb visible radiation absorption. A favourable porous structure was obtained for the membranes, with an average pore size of 4 μm, and the nanoparticles immobilisation did not alter the chemical properties of the polymeric membrane. The produced hybrid materials, including both the Au/TiO2 and Y2(CO3)3 nanoparticles, presented an efficiency of 57% in the degradation of norfloxacin (5 mg/L) under ultraviolet radiation for 120 min, 80% under visible radiation for 300 min, and 58% in arsenic adsorption for 240 min. These membranes represent a new multifunctional platform for removing several pollutants, which may allow their incorporation in more efficient and less energy-consuming water treatment processes favouring its application, even in low energy resources countries.

Electrochemical oxidation of aniline using a high-flux CNT filter

Carbon nanotube (CNT) membrane electrochemical filtration has been found to provide effective solutions for water contaminant removal. However, bubble elimination, water flux increase, and CNT membrane robustness enhancement still remain great challenges for CNT electrochemical filtration technologies. To improve the performance of the electrochemical CNT filter, a ceramic flat membrane is used as the CNT electrode support. Aniline (AN) is chosen as the target pollutant to investigate the effects of water quality (initial pH, initial AN concentration, and support electrolyte concentration) and running conditions (anode potential and water flux). In addition, the current efficiencies (CE) of the two different modes (single-pass filtration and recirculated filtration) are also estimated. The results showed that the effects of various impact factors on the AN degradation were generally similar in both modes. Overall, the CEs of the sing-pass filtration mode with the stable influent conditions were higher than those of the recirculation filtration mode. Increasing the flux and applied anode potential did increase the AN degradation rate. The maximum water flux density of the high-flux CNT electrochemical filter reached 83.9 mL/(cm2·h), 4.0–16.1 fold of that of a typical CNT electrochemical filter, addressing the defects of bubble formation and CNT fragility of the free-standing BUCKYPAPER membrane in a conventional electrochemical filter. The configuration with a ceramic membrane support greatly improved the practicability of CNT-based electrochemical filtration technology for real wastewater treatment.

Performance of Home-Made Activated Carbon Ceramic Filter on Quality of Surface and Underground Water from Msambweni, Kwale County, Kenya

About 17 million Kenyans lack access to clean water, causing fears of water-borne diseases. This is a consequence of contaminants introduced through human acts, including agricultural activities, industrialization, poor waste disposal, and poor drainage. In Msambweni, Kwale County, the scenario is not any different. The removal of contaminants in water to reach the World Health Organization and Kenya Bureau of Standards permissible qualities of clean water for human consumption is generally expensive. This is a challenge for residents of Msambweni, who 74.9 % live below the poverty line. This research aimed at fabricating an activated carbon-ceramic (ACC) filter using locally available finely crushed clay and sawdust and test its efficiency, i.e. removal of Escherichia coli and total coliform, the effect on temperature, turbidity, total dissolved solids, dissolved oxygen, salinity, pH, electrical conductivity, dissolved ions of Na + , K + , Ca 2+ , Mg 2+ , HCO 3 - , Cl - and SO 4 2- . The test was carried on three selected water sources of deep underground, hand pump, and surface water before and after filtration using the ACC filter. The physicochemical parameters were measured using an aqua read meter while the aqua genx test kit was employed for the bacteriological analysis. Na + , K + , Ca 2+ , Mg 2+ , HCO 3 - , Cl - and SO 4 2- were analyzed using atomic absorption spectroscopy (AAS) and calorimetry. Statistical analysis was performed by SPSS software version 21. The turbidity and DO were beyond the WHO recommended limits at (30.00±1.00 NTU) and DO (4.21±0.96 mg/L) from the specimen drawn from hand pumps before filtration. The Mean±SE ranged from 22.72±1.15-23.24±1.22°C (Temperature); 4.99±0.01-30.00±1.00 NTU (Turbidity), 51.12±31.85-68.62±66.93 mg/L (TDS), 4.21±0.96-7.48±0.33 mg/L (DO), 3.85±0.78-5.17±0.56 mg/L (salinity), 7.37±0.15-7.46±0.02 (pH) and 0.18±0.01-0.87±0.03 mg/L (EC). These levels decreased significantly after filtration of the water samples using the fabricated ACC Filter, subsequently falling within admissible limitation in line with the WHO excellence levels. Amounts of Faecal E. Coli (CFU/100 ml) and Faecal Coliforms (MPN/100 ml) before filtration ranged between 1.00±0.00 - 5.00±0.00 and 12.00±00 - 25.00±0.00 respectively, being higher than the WHO standards. However, the levels decreased significantly after filtration falling within permissible levels. The levels of dissolved ions (mg/L) were within WHO standards before filtration (BF). Notably, Mg 2+ ranged from 1.04±0.01 in underground water and HCO 3 - ranged 225.67+0.58 in the surface water samples. These levels decreased to 0.35±0.01 for Mg 2+ and 30.50+0.10 for HCO 3 - in underground and surface water samples, respectively, after filtration. The fabricated ACC Filter was found to remove Faecal E. Coli effectively and Faecal Coliforms in all water samples, improving turbidity but with minimal effect on dissolved ions in water hence recommended for use. Keywords: Activated carbon, Ceramic filter, Surface water, Underground water, Water sampling DOI: 10.7176/JEES/12-1-04 Publication date: January 31 st 2022

Ultrathin Bi4O5Br2 nanosheets with surface oxygen vacancies and strong interaction with Bi2O2CO3 for highly efficient removal of water contaminants

Ultrathin Bi4O5Br2 nanosheets with surface oxygen vacancies and strong interfacial interaction with Bi2O2CO3 for highly efficient removal of water contaminants.