Ruth Wanjau

• Bachelor of Education, Master of Science, Doctor of Philosophy
• Coordinator, Peer Counselors at Kenyatta University

Consumption of water contaminated with heavy metal ions compromise human and animal wellbeing even at permissible limits. Therefore, their removal from water is very important for the safety of consumers. Previously used conventional water treatment techniques were expensive and ineffective. Among them, adsorption has gained research interest b...

This study presents a fixed-bed column adsorptive behavior of Silicon Nitride (Si3N4) adsorbent for Methylene blue dyes. The adsorbent was characterized using XRD and EDX. Effect of parameters such as influent concentrations, volumetric flow rate, and bed height for the column study are explored. The Yoon-Nelson, Thomas, and Adam-Bohart models...

The present work investigates the chemical properties of natural sand obtained from Crescent Island Crater in Lake Naivasha catchment, Kenya. Fourier Transform Infra-Red (FT-IR), X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD) spectroscopic analysis was performed. The XRD results showed that quartz (SiO 2), calcite (CaCO 3), clinochlore ((Mg,...

The extensive use of silicon carbide in many fields such as in abrasives, structural materials, refractories, electronic components, and nuclear reactors amongst others demands for an innovative, cheaper, and an environmentally friendly approach for its synthesis. The aim of the study was to use coffee husk wastes as silica and carbon sources in Si...

The continued coffee demand in Kenya has amplified the generation of its husk wastes causing disposal problems. This has led to serious pollution to the environment. Therefore, developing a greener and cost-effective ways to handle these wastes is necessary. The current study entailed the use of extracted silica and coffee husk biochar as nov...

The current study showed utilization of locally available beach sand from Marine National Park in facile extraction of highly amorphous silica via a simple alkali fusion method. The purification of the silica sand was done using 6 N HCl solution to increase its purity. The method entailed formation of sodium silicate (Na2SiO3) solution from silica...

ABSTRACT: The current study showed utilization of locally available beach sand from Marine National Park in facile extraction of highly amorphous silica via a simple alkali fusion method. The purification of the silica sand was done using 6 N HCl solution to increase its purity. The method entailed formation of sodium silicate (Na2SiO3) solution fr...

There is increased range of human health disorders due to exposure to toxic metals such as lead as well as negligible levels of essential elements in the bodies of males. exposure to lead may emanate from manufacturing industries (where males predominate), consumption of exposed and canned foods among other lifestyle changes. Human males are poor e...

This paper reports on the preparation and modification of azotized polyethylene terephthalate (PET) as a stable and colour sensitive absorbent for metals in aqueous media and its application in the removal of heavy metal ions from water. This study successfully functionalized PET to produce an azotized material which was confirmed by FTIR (Fourier...

Consumption of water contaminated with dyes and phenolic compounds is detrimental to human and animal wellbeing even at permissible limits. Therefore, their decontamination from water is important for the safety of consumers. Conventional water treatment techniques such as ozonation, ion exchange among others are expensive and ineffective. Adsorpti...

Water is vital to humans, animals and the entire ecosystem. However, its quality is deteriorating every dawn due to increased industrial advancements in our contemporary society leading to careless discharge of both organic and inorganic pollutants to the environment. This is not limited to metal ions which are eventually disposed to water bodies....

Presence of heavy metals in drinking water has significant adverse effects on human wellbeing due to their toxicity nature. Several techniques have been employed to reduce their concentration to permissible levels. In recent years, adsorption has been widely investigated from low-cost adsorbents due to their cost effectiveness and easy in design. T...

Water is essential for every life processes. However, its quality is deteriorating every day due to the recent industrial advancements. Anthropogenic processes such as industrialization, mining and agricultural activities have led to alarming discharge of heavy metal ions to the aquatic bodies. This possess a greater threat to human, animal and the...

Abstract Anthropogenic activities contribute large amounts of pollutants to the environment which threaten animal and human health. There is increased realization of the effect of these toxins on surface and ground water, consequently, their elimination is vital in rendering secure water for drinking as well as culpable release of effluents to our...

The present study used Jackfruit seeds (JS) as a novel adsorbent in adsorption of Cr3+ ions from an aqueous solution. A modified Jackfruit seeds (MJS) adsorbent was prepared by chemical treatmentof unmodified Jackfruit seeds (UJS) with hydrochloric acid. Both UJS and MJS were characterized by FTIR which showed increased in the number of negatively...

Phenolic compounds are injurious to human and animal health, for instance PNP is an eye irritant and its ingestion or inhalation brings about vomiting, sleepiness, headaches and ataxia. Interaction of PNP with blood leads to confusion, cyanosis and unconsciousness. Conventional water treatment methods for example; use of activated carbons involve h...

Heavy metals contamination in drinking water is of great concern because of their toxicity and non-biodegradability. Therefore, their removal is paramount. Recently, adsorption has gained a great attention from researchers due to availability of the materials and associated capacity compared to conventional methods of water treatment. Various chemi...

The purpose of this study was to assess the ethnobotanical uses of Plecranthus esculentus N.E.Br in Makoni district, Zimbabwe as well as to evaluate the phytochemical profile of aqueous acetonic extract of the plant tubers using UV-Visible spectrophotometry, Fourier transform-Infrared (FTIR) analysis and high performance liquid chromatography (HPLC...

Flesh from animals is one of the nutritious foods rich in vitamin B complex, iron, zinc, selenium, phosphorous, fats and magnesium. Due to this high food value, it attracts bacteria, yeasts, molds and other lower life forms that infest on it and hence undergoes natural decay process fast. Poor handling practices by small scale enterprise in the bee...

This study reports on the treatment of wastewater containing dissolved organic matter (DOM). DOM introduces complexing agents, promotes bacterial growth, and affects the color plus taste of water negatively. The normal practice for treatment such pollutants is the use of introduction of oxidizing agents in the water. However, this introduces second...

The desire to improve physical appearance has led to increased use of lipstick by millions of women. This is despite research showing that some brands of lipsticks are contaminated with higher levels of the heavy metals above the permissible level tolerable by the body. This study was conducted to determine the presence and concentration of lead, c...

Modern people have embraced plants as a source of useful bioactive compounds. As such, plants with medicinal properties have become essential components in human life. The purpose of this study was to investigate the phytochemical profile of the extract of Dioscorea steriscus tubers obtained from Zimbabwe. Phytochemicals were extracted from tubers...

Aim: The aim of the present study was to determine the possibility of using polyphenol extracts from Dioscorea steriscus and Plecranthus esculentus N.E.Br tubers of Zimbabwe as preservatives for sunflower oil under oven and kitchen storage conditions. Methodology: Polyphenols were extracted from Dioscorea steriscus and Plecranthus esculentus tuber...

Loss of available land for plant growth has made other options that allow an efficient use of water and fertilizers which increase crop quality and productivity. Some systems such as hydroponics need a constant air and fluid circulation as well as nutrient refill that put strain on the cost of production. Without such a system, many growers dump th...

Introduction This study reports on water management in the fields found in arid areas by the improvement of the soil’s water retention capacity. This was done using hydrogels from animal wastes to mitigate the effects of climate change that lead to rapid evaporation of water hence increased desertification rates. Method The modification of the cow...

This paper reports the removal of fluoride ions in stored drinking water by a container made from chemically modified polyethylene material. To anchor triethylamine within the structure of the polyethylene material and improve its value, the polyethylene was first heated to melting. To the molten material, hot vegetable oil was added slowly with co...

Nyaitondi OD, Wanjau R, Nyambaka H, Hassanali A. 2018. Anti-bacterial properties and GC-MS analysis of extracts and essential oils of selected plant product. Biofarmasi J Nat Prod Biochem 16: 44-58. Plants are traditionally used for the treatment of bacterial infections though they are not clinically regulated due to lack of awareness and sufficien...

The presence of heavy metals in water is of concern due to the risk toxicity. Thus there is need for their removal for the safety of consumers. Methods applied for removal of heavy metals include adsorption, membrane filtration and co-precipitation. However, studies have revealed adsorption is highly effective technique. Most adsorbents are expensi...

Untreated wastewater is often recycled in peri-urban subsistence farming. This water may contain residues of pharmaceutically active compounds discharged into the wastewater. Of concern are the residues of trimethoprim and sulfamethoxazole which are administered synergistically under the brand name septrin or cotrimoxazole. These two antibiotics ar...

The levels of chloride (Cl-), fluoride (F-) and iodide (I-), in amaranth (Amaranthus hypochondriacus and Amaranthus cruentus) leaves at different stages of maturity (25 days, 50 days and 75 days) and seeds from four counties (Kiambu, Kericho, Bungoma and Kisii) of Kenya were quantitatively determined. The levels were determined using potentiometric...

This is a report on comprehensive characterization of cadmium (Cd)-exposed root proteomes in tomato using label-free quantitative proteomic approach. Two genotypes differing in Cd tolerance, Pusa Ruby (Cd-tolerant) and Calabash Rouge (Cd-sensitive), were exposed during 4 days to assess the Cd-induced effects on root proteome. The overall changes in...

Several methods for the removal of fluorides in water have been proposed, most of which rely on the use of biomaterials and bone char. In such processes, the adsorbent become loaded with the pre-concentrated pollutant leading to a disposal problem. This study reports on the modification of the maize tassels with triethylamine followed by its subseq...

Chlorine added to drinking water as a disinfectant is a concern of this generation. This is because chlorine reacts with dissolved organic compounds to form polychlorinated complexes that are carcinogenic. Available methods for the removal of chlorine and chlorinated compounds include adsorption, precipitation, electrolysis and ozonation, but some...

World Health Organization (WHO) among other health agencies recommends exclusive breast feeding during the first six months of infancy. However, Infant formula milk (IFM) has been increasingly used as a breast milk substitute due to maternal occupation, death and illness. The product has been associated with infant health complications and even dea...

Trace elements are essential in preserving good health and body immunity to diseases. The study was undertaken to determine the levels of chromium (Cr), vanadium (V), selenium (Se) and zinc (Zn) in herbal spices, food grains and edible seeds commonly used in Kenya. The levels of elements were determined using atomic absorption spectroscopy (AAS). T...

The aim of this work was to determine the level of inorganic anions (NO 3-, Cl-, SO 4 2-, PO 4 3-, F-and I-) in the leaves of two species of amaranth (Amaranthus hypochondriacus and Amaranthus cruentus) planted in Kenya. The mean levels of inorganic anions, nitrate (NO 3-), chloride (Cl-), sulphate (SO 4 2-), phosphate (PO 4 3-), fluoride (F-) and...

Infant formula milk has been increasingly used as a breast milk substitute as a result of maternal occupation, death and illness. This happens despite the United Nations, World Health Organization, international and national health agencies recommending exclusive breast feeding during the first six months of infancy. Following this, infant formula...

Lead and zinc concentrations were determined in scalp hair and finger nails of exposed and unexposed males by atomic absorption spectrometry (AAS). The mean levels of Pb in the finger nails ranged from 50-480 μg/g, and 50-240 μg/g for exposed and unexposed males respectively. The mean levels of Pb in the scalp hair ranged from 30-410 μg/g, and 30-2...

This study was carried out to determine the levels of nitrate, nitrite and phosphorus in homemade brews, spirits and the raw materials used using the UV-Visible spectroscopy. Nitrate and nitrite were analyzed using a SHADZU (Model No. UV-2550), phosphate was analyzed using and a Philips, Scientific equipment, UP-8700 Series UV-Visible spectrophotom...

The enrichment by microbial fermentation of agro industrial waste to alleviate their nutritional problems has been proposed but the nutritional value of the subsequent feed for animal consumption has not been fully elucidated. This study investigates whether solid state fermentation of pineapple waste using the fungi Aspergillus niger and Trichoder...

Homemade brews and the raw materials used can be a major source of nitrate and nitrite in human diet. Because of the potential health hazards result in . high intake of nitrate and nitrite, determination of these ions content in Homemade brews and the raw materials used. Sources of nitrites include vegetables, fruit, and processed meats The aim of...

This study was carried out to determine the levels of arsenic in the home-made brews, home-made spirits, raw materials and water. One hundred and thirty two home -made alcoholic beverages, one hundred and ten water and eighteen raw materials samples obtained from various parts of Nairobi slums and its environs were analyzed for arsenic. The method...

Increased cases of deaths as a result of taking home made brews/spirits have been a major concern in our country. Recently, many lives have been lost due to the ignorance of the brewers and their patrons. This study was carried out to determine the levels of nitrate in home -made brews, home -made spirits, raw materials and water. Four hundred and...

The purpose of the study was to determine how the levels of calcium, phosphorus and zinc affected the levels of lead in the human blood. The levels of lead, calcium, zinc and phosphorus in human blood of subjects from Nairobi city centre, Nyamira town, Nairobi suburban and Nyamira rural, Kenya are presented in this article. The subjects in Nairobi...

The study dealt with assessment of demographic and risk factors of lead exposure by people living in Nairobi and Mathira in Kenya by use of a standard questionnaire. The study subjects were the public vehicle drivers/conductors, people working in petrol stations, street hawkers, traffic policemen, artisans, those people who spend most of their time...

The paper presents the study carried out in a peri urban settlement of Nairobi Kenya and involved treatment of raw grey water generated from bathroom, kitchen and laundry for flushing toilet and laundry work. The study utilized both chemical and physical treatment. The chemical treatment involved alum addition in the raw grey water and pH adjustmen...

This paper describes the determination of the levels of lead (Pb), cadmium (Cd), zinc (Zn), calcium (Ca) and iron (Fe) in the toenails and fingernails of children under the age of six years in urban and rural areas in Kenya by atomic absorption spectrophotometer. Lead levels in urban areas ranged from 8.0-49.0 µg/g in fingernails and 7.0-62.0 µg/g...

This study was carried out to determine the levels of nitrate in homemade brews, spirits and the used raw materials using the UV-Visible spectroscopy. These were analyzed using, a SHADZU (Model No. UV-2550) UV-Visible spectrophotometer. The measurement was based on ISO Method (N0.6635). This was done by reducing the nitrate to nitrite in the presen...

Metal pollution and its health effects present a challenge currently facing the developing countries. Metal poisoning is usually difficult and expensive to assess or screen in these countries due to limited resources, which means that policies, guidelines, regulations and institutional managements are limited. Hair and nail as biopsy materials were...

Using PTFE as a chemical modifier, a method for the determination of trace impurities in high purity Nd2O3 by in-situ separation and electrothermal vaporization-inductively coupled plasma-atomic emission spectrometry (ETV-ICP-AES) was developed. The analyte-matrix separation and the temperature program of graphite furnace were investigated and opti...

A new method for the separation and detection of trace metal impurities in cerium oxide (CeO2) using HPLC combined with electrothermal vaporization (ETV)-ICP-AES was developed. This combination links the high separation power of HPLC and high sensitivity of ETV-ICP-AES. The 2-ethylhexyl hydrogen 2-ethylhexylphosphate (P507) resin was used as statio...

This article describes a new method for the simultaneous determination of trace rare earth elements (REEs) and non rare earth elements (NREEs) in high purity terbium oxide by ICP-AES after HPLC separation using P507 resin. The chromatographic separation of the analytes from the matrix using dilute nitric acid as mobile phase was studied. The exper...

A new method for the determination of trace non-rare earth elements (NREEs) impurities in high-purity lanthanum oxide by HPLC combined with ICP-AES is proposed. The chromatographic retention behaviors of matrix (La) and NREEs were studied using 2-ethylhexyl hydrogen 2-ethylhexyl phosphonate (P507) chelating resin as the stationary phase and dilute...

A method is proposed to determine trace rare earth impurities in high-purity CeO2 by HPLC combined with electrothermal vaporization inductively coupled plasma atomic emission spectrometry (ETV-ICP-AES). The Chromatographie retention behaviours of the matrix (Ce) and rare earth impurities were studied using 2-ethylhexyl hydrogen 2-ethylhexyIphosphon...