In recent years, the removal of heavy metals from water and wastewater systems remains a challenging issue globally. Adsorption technology is widely used for the removal of heavy metals from aquatic systems due to several advantages including its simple operation, low cost and high efficiency. Biochar, which is an environmental benign and low-cost adsorbent, is increasingly used for remediation of heavy metal pollution in aquatic systems. This review critically analyzes recent developments on the biochar-based adsorptive removal of heavy metals from water and wastewater. Biochar is effective for the removal of several toxic metals (As, Cr and Mn) from groundwater and drinking water. Biochar also shows promising performance for the removal of various heavy metals (Cr, Pb, Cu, Cd and Zn) from wastewater. The heavy metal adsorption capacity of the biochar largely depends on the water/wastewater chemistry (pH, competing ions and initial concentrations of adsorbates), contact time between adsorbates and the adsorbent, adsorbent dose and environmental parameters (temperature). The adsorption isotherms and kinetics can be well explained by the Langmuir and pseudo-second order models, respectively. The key mechanisms which drive the heavy metal adsorption onto biochar include precipitation and ion exchange. Biochar-based adsorptive decontamination of heavy metal pollution is sustainable due to low environmental impacts, low energy consumption and low-costs. The key knowledge gaps and future research directions for improvement of biochar-based sorption capacities are highlighted. This review would help for the development of effective biochar-based adsorption technology for the removal of heavy metals from aquatic environments. 

Use of biochar as a low-cost adsorbent for removal of heavy metals from water and wastewater: A Review

A review on algal biosorbents for heavy metal remediation with different adsorption isotherm models

The objective of this study is to transform chitosan biopolymer by crosslinking with barbituric acid into an amine-rich product that could be applied as a water treatment agent. Chitosan-barbituric acid (CBA) was synthesized by lyophilization process and characterized using FT-IR, XRD, TGA-DTA, SEM-EDX, BET surface area and BJH pore size distribution analysis. The pHpzc was found to be 7.7 indicating applicability towards both cations and anion adsorption. The CBA was used for seizure of CrVI and CN– from aqueous solutions in batch adsorption as well as fixed bed column experiments. Response surface methodology (RSM) was used as a statistical tool to optimize the functioning parameters resulting in more than 90 % removal of these ions. As shown by isotherm and kinetics data, Langmuir isotherm and pseudo second order kinetics exhibited a good fit for the adsorption process. The maximum adsorption capacities of CBA towards CrVI and CN– evaluated using Langmuir isotherm fitment were 534.75 mg g−1 and 251.66 mg g−1 at pH 4.0 and 6.0 respectively. Thermodynamic studies indicated spontaneous and enthalpy driven course with large negative enthalpy changes of −56.39 and −31.81 kJ mol−1 respectively. Fixed bed column studies showed that the material could be used for larger sample volume treatment even at 200 mg/L CrVI and 100 mg/L CN−1 concentration. Regeneration studies of adsorbent was conducted over five adsorption–desorption cycles with removal efficiency more than 50 %indicating reusability of the adsorbent. Analysis of adsorbent sustainability revealed that the synthesis was eco-friendly as indicated by low value of E-factor of 0.32. 

A novel Chitosan-Barbituric acid hydrogel supersorbent for sequestration of chromium and cyanide ions: Equilibrium studies and optimization through RSM

The removal of pharmaceutical pollutants from aqueous solution by Agro-waste

In this study, banana peel powder (BPP) was used to remove carcinogenic crystal violet (CV) dye from aqueous solution. The BPP adsorbent was characterized by Fourier-Transform Infrared (FTIR) spectroscopy and Scanning Electron Microscopy (SEM). In batch sorption experiments, the maximum removal of CV was recorded 93% at optimum levels of operating parameters, i.e., pH 7.0, adsorbent dosage 0.1 g, contact time 10 min, initial adsorbate concentration 90 ppm and temperature 20 C o. The kinetics of the adsorption process was found best to follow the pseudo first order model with high value of R2 (0.9999) and low values of error functions. The Langmuir isotherm model was the best fit with high R2 (0.9552) low values of error models. The plots of Freundlich and D-R isotherms confirmed the feasibility (n = 1.3109 L g−1) and the physisorption nature (Es= 0.1107 kJ mol−1) of the process respectively. The negative values of thermodynamic parameters (ΔG & ΔH) revealed that the adsorption was spontaneous and exothermic in nature respectively. The results of the desorption study showed that 91% of the adsorbent was regenerated. The novelty of the present research is that no work has been reported till date to remove crystal violet dye by using banana peel specifically. The high adsorption and desorption efficiencies (>90%) suggest that BPP possesses characteristics to be used as an effective, fast and low-cost adsorbent for adsorption of CV dye from industrial effluents. HIGHLIGHTSAdsorption technique was employed to remove crystal violet dye by using banana peel powder.The hydroxyl (OH−) & carboxylate (OH−) groups on adsorbent surface provided excellent binding with adsorbate molecules.Equilibrium attainment in 10 min at neutral pH.93% adsorption and 91% desorption. 

Adsorptive removal of hazardous crystal violet dye onto banana peel powder: equilibrium, kinetic and thermodynamic studies

Adsorption Kinetics describes the rate at which solute is adsorbed and the resident time of the adsorbates on the solid-liquid interface. Adsorption isotherms play important role in determining the interaction between adsorbate and adsorbent and the optimum adsorption capacity of adsorbent. This article considered selected adsorption kinetics and isotherms models. Pseudo first order, Pseudo second order, Elovich, Bhattacharya and Venkobachar, and Natarajan and Khalaf were adsorption kinetics reviewed on the assumption that the process behaves as heterogeneous reaction at solid-liquid interface. Adsorption kinetics equation presented takes the form of straight line, the slopes and intercepts of the plots are used to determine adsorption capacity of adsorbent, rate constant, rate of adsorption and intraparticle diffusion. Value of correlation coefficient obtained is used in determining the adsorption kinetics model that best describe the adsorption process. Langmuir, Freundlich, Radlich-Peterson, Temkin and Dubinin-Radushkevic adsorption isotherms were presented. Their slopes and intercepts provide insight on adsorption affinity, mean free energy, whether the adsorption is physisorption or chemisorptions, single or multilayer. Adsorption kinetics and isotherms reviewed provide essential information required for understanding adsorption process. 
Keywords:   Adsorption; kinetics; isotherms; pseudo first order; Langmuir

/pdf/adsorption-kinetics-and-isotherm-models-a-review-2982yx40.pdf

Adsorption Kinetics and Isotherm Models: A Review

The study establishes some important pharmacognostic profile of Commiphora africana leaf and stem-bark with the hope of assisting in its proper identification as well as standardization for quality and sample purity. Evaluation of the fresh, powdered and anatomical sections of the leaves and stem bark were carried out to determine the macromorphological, micromorphological, chemomicroscopic and some physicochemical parameters. Macroscopical studies indicated presence of leaf with trifoliate arrangement, crenate margin with ovate shape, acute apex, cuneate base, petiolate with pinnate venation. The microscopy revealed the dorsiventral nature of the leaf and was observed to be hypostomatic with anomocytic type of stomata, with numerous unicellular covering and glandular trichomes on the abaxial surface. Chemomicroscopic characters present include; lignin, starch, cellulose, tannin, suberin and calcium oxalate crystals. The physicochemical parameters evaluated include moisture contents (8.1%), total ash value (9.3%), water soluble ash (5.5%), acid insoluble ash (3.2%), ethanol extractive values (22.3%) and water extractive values (19.0%). For quantitative leaf microscopy, on the average, stomatal number (38.0) and index (25.0), palisade ratio (11.7), vein termination numbers (5.7) and vein islets (1.3). The microscopy of stem bark revealed some prominent features like the cork, prism types and microcrystal of calcium oxalate crystals, fibres, phloem parenchyma cells, secretion canal and medullary ray. The physicochemical parameters evaluated include moisture contents (8.6%), total ash value (11.3%), water soluble ash (7.0%), acid insoluble ash (2.7%), ethanol extractive values (12.3%) and water extractive values (9.3%). Keywords: Commiphora africana, Macroscopic, Microscopic, Physicochemical parameters

Pharmacognostic evaluation of the leaves and stem-bark of Commiphora africana (A. Rich) Engl. (Burseraceae).

Traditional Birth Attendants (TBAs) are found in most communities in the world. Although their nature and functions varied considerably. Their practices aimed at providing medical related services for the maintenance of good maternal health, particularly through ensuring good delivery. Original Research Article Abdulhamid et al.; JOCAMR, 2(2): 1-7, 2017; Article no.JOCAMR.27773 2 The study aimed to assess the perceptions of women on TBAs in Zaria Kaduna State, Nigeria. The State is part of Hausa and Fulani land where ethno medicine is recognised and highly practiced. Hausa and Fulani tribes of Zaria were selected for the study. A total of 200 women were randomly selected and interviewed. The information provided were recorded on structured questionnaires. The results showed that TBAs have made great impact in such communities. Low risk perception regarding their personal susceptibility to pregnancy and labour complications was one of the main reasons why most old women with many children delivered at home and utilized TBAs. Respondents showed that TBAs are available at any time, easily accessed, always reliable for pregnant patient women to attend at any moment, caring of women in labour or outside labour. Also they rendered their services to maximum capacity. Respondents in the study area indicated their confidence and beliefs towards utilizing TBAs services. In conclusion pregnant women’s positive attitude towards TBAs was one of the main reasons why most of them preferred the services provided by TBAs. There is no doubt that such TBAs will continue to play an important role in health care provision in the study area. Therefore, comprehensive training of TBAs to act as primary health care workers in community should be considered and implemented.

/pdf/perceptions-of-hausa-and-fulani-tribes-on-traditional-birth-44gal6zdwr.pdf

Perceptions of Hausa and Fulani Tribes on Traditional Birth Attendants in Zaria Local Government Area, Kaduna State, Nigeria

The present study investigates the phytochemicals and thin layer chromatographic profile of Nauclea diderrichii (Rubiaceae) leaf extracts. Phytochemical in the hexane, ethyl acetate and methanol extracts were determined using standard chemical tests. Thin layer chromatographic techniques were carried out using various solvent systems of varying polarity on these extracts. Preliminary phytochemical screening revealed the presence of alkaloids, glycosides, saponins, phenolic compounds, tannins, phytosterols, carbohydrates, flavonoids and terpenoids. Further screening using thin layer chromatographic technique on the N. diderrichii leaf extracts also revealed different phytochemical compounds with different Rf values. The results obtained in present study indicated that Nauclea diderrichii leaf is a rich source of phytochemicals. This could justifies the use of plant species in traditional medicine for treatment of various diseases. Keywords : Nauclea diderrichii , Rubiaceae Leaf extracts, Phytochemicals, Retention factor, TLC.

/pdf/phytochemical-screening-and-thin-layer-chromatographic-378vwa8j5a.pdf

Phytochemical screening and thin layer chromatographic profile of Nauclea diderrichii leaf extracts

This work studied the proximate, mineral and phytochemical content of fermented and roasted Tamarind (Tamarindus indica) seed nuts, using standard analytical methods. The seeds were divided into two; one portion was roasted at temperature 85 - 100 oC for 15 mins while the second portion was fermented for 48 hours in the presence of yeast. The proximate analysis of the roasted and fermented samples revealed the values of moisture, ash, crude lipid, Crude protein, crude fibre, carbohydrate and calorific values of the fermented sample were 10.70±0.21 %, 3.06±0.71 %, 2.30±0.19 %, 19.25±0.16 %, 5.75±0.33 %, 58.94±0.23% and 301.29±0.31kcal/100g while values for the roasted sample were 2.00±0.82 %, 3.34±0.53 %, 7.60±0.43 %, 23.63±0.11 %, 5.22±0.74 %, 58.21±0.17 % and 329.08±0.92 kcal/100g respectively. Mineral elements present were K (336.75±0.31 mg/100g), Mg (166.90±0.37 mg/100g), P (106.42±0.65 mg/100g), Na (186.52±0.09 mg/100g) and Ca (10.33±0.15 mg/100g) for the fermented sample and values obtained for K, Mg, P, Na and Ca in roasted sample were 784.95±0.43, 187.65±0.17, 122.38±0.29, 54.36±0.13 and 12.65±0.11 mg/100g respectively. Results of phytochemical content showed that fermented Tamarindus indica contained tannin (64.61±0.43 mg/100 g), saponnins (127.33±0.79 mg/100 g), flavonoid (3.53±0.18 mg/100 g) and alkaloid (23.56±0.37 mg/100 g) while phytochemicals in the roasted sample were 40.97±0.21, 94.69±0.29, 1.96±0.51 and 14.33±0.12 mg/100g for tannins, saponins, flavonoid and alkaloids respectively, and were significantly lower than those in the fermented sample. Correlation analysis indicate a correlation exist between nutritional content of fermented and roasted samples of T. indica. The high crude protein, carbohydrate, calorific value and mineral content in fermented and roasted T. indica seeds indicate that the seeds could be good source of nutrient.

/pdf/nutritional-assessment-of-fermented-and-roasted-tamarindus-11m4nq51.pdf

Nutritional Assessment of Fermented and Roasted Tamarindus indica Seeds from Lapai, Nigeria

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Z. Abdulhamid

Author Tools

Chat about Author