A review of pharmaceuticals and endocrine-disrupting compounds: sources, effects, removal, and detections

There are growing concerns about the increasing trends of emerging micropollutants in the environment due to their potential negative impacts on natural ecosystems and humans. This has attracted attention from both governmental and non-governmental organisations worldwide. Pharmaceuticals, personal care products, and endocrine disruptors are continuously being released consciously or unconsciously into water sources due to poor regulatory frameworks especially in the developing countries. The effects of these contaminants are poorly known. They are not easily biodegradable and have become an environmental nuisance and public health issue. This has heightened the risk of exposure to their deleterious effects in such countries where the majority of the population are still struggling to have access to good quality drinking water supplies and better sanitation. With the rising fear of short- and long-term impacts of the ever-increasing number of persistent recalcitrant organic compounds accumulating in the environment, their removal is gradually becoming an issue to the water treatment industry. Hence, there is a need to develop functional techniques for the management of water contaminated by these emerging contaminants so as to increase the availability and access to safe and good-quality drinking water. We conducted a narrative review on these emerging micropollutants and examined their various documented sources, effects, as well as recent techniques for their effective removal. This becomes necessary due to the increasing occurrence of these pollutants in the aquatic and terrestrial environment. These levels are expected to further increase in the coming years as a consequence of the ever-increasing population density which undoubtedly characterizes developing economies. Our findings show that the present reported treatment techniques in the literature such as biological oxidation/biodegradation, coagulation/flocculation, ozonation, el ectrodialysis, reverse osmosis, sedimentation, filtration, and activated carbon were not designed for removal of these newly identified contaminants, and as such, the techniques are not sufficient and unable to completely degrade the compounds. We therefore recommended the need for concerted efforts to develop better techniques, especially combined advanced oxidative methods to address the shortcomings of and growing challenge to current practices.Web of Scienc

Effects of Some Heavy Metals on Chlorophyll Accumulation in \u3cem\u3eBarbula lambarenensis\u3c/em\u3e

Samples of moss (Barbula lambarenensis) with their substrates collected from Belewu Drive, Oke Odo, Ilorin, were taken to the screen house of the University of Ilorin biological garden to monitor the effects and tolerance of this plant to different heavy metals. The moss samples were divided into eleven regimes, widely separated from one another to avoid contaminations. Ten regimes were differently irrigated with 1000 ppm and 2000 ppm of lead, copper, cadmium, iron and vanadium thrice a week. The eleventh treatment served as the control, and was irrigated with distilled water. It was found that these heavy metals caused some damage to the chloroplasts of this plant as the bright green colours changed light green, yellowish green or brown. The concentrations of the used heavy metals are phytotoxic. In light of this, Barbula lambarenensis can serve as a bio-indicator of heavy metals

Quantification of radicals generated in a sonicator

The hydroxyl radical (OH•) is a powerful oxidant produced as a consequence of cavitation in water. It can react nonspecifically in breaking down persistent organic pollutants in water into their mineral form. It can also recombine to form hydrogen peroxide which is very useful in water treatment. In this study, terephthalic acid (TA) and potassium iodide dosimetry were used to quantify and investigate the behaviour of the generated OH radical in a laboratory scale sonicator. The 2-hydroxyl terephthalic acid (HTA) formed during terephthalic acid dosimetry was determined by optical fibre spectrometer. The production rate of HTA served as a means of evaluating and characterizing the OH• generated over given time in a sonicator. The influence of sonicator power intensity, solution pH and irradiation time upon OH• generation were investigated. Approximately 2.2 x 10-9 M s-1 of OH radical was generated during the sonication process. The rate of generation of the OH radicals was established to be independent of the concentration of the initial reactant. Thus, the rate of generation of OH• can be predicted by zero order kinetics in a sonicator

Assessment of heavy metal contents of Lycopersicum esculentum mill. (tomato) and Capsicum chinense l. (pepper) irrigated with treated and untreated detergent and soap wastewaters

Tomato and pepper are staple and common vegetables consumed by all classes of Nigerian populace. Due to high consumption rate of these vegetables, they are cultivated all year round in many localities including the peri-urban cities. The problem of freshwater scarcity in peri-urbancities and the northern part of Nigeria has made peasant farmers in these areas to resolve to the use of wastewaters for irrigation with no knowledge of their status and safety. Therefore, the level of heavy metal contents in Lycopersicum esculentum and Capsicum chinense grown in the Screen House of the University of Ilorin, North-central Nigeria were studied using treated and untreated detergent and soap wastewaters. Fallowed soils collected from the University Botanical Garden, homogenized and packed into planting bags were used for the experiment. Viable seeds of Lycopersicum esculentum and Capsicum chinense were sown in 10 planting bags for each crop and irrigated with 0%, 5%, 10%, 20% and 40% Treated and Untreated wastewaters. After 12WAP, leaf samples of Lycopersicum esculentum and Capsicum chinense were collected, air-dried, digested and the digests were analyzed for Manganese (Mn), Copper (Cu), Chromium (Cr), Lead (Pb) and Cadmium (Cd) by Atomic Absorption  Spectrophotometry. It was evident that there was prevalence of heavy metals in the wastewaters particularly the untreated wastewater and the content of the heavy metals were concentration-dependent in theleaves of the test crops. It is therefore imperative to inform and enlighten the local farmers and the consumers on the danger of using such water for irrigation of agricultural crops in order to ensure safety

Geochemical Partitioning of Major Elements in Brine Impacted Coal Fly Ash Residues

Fly ash-brine co-disposal technique has been considered as a way of disposing fly ash and brine (hyper-saline water) by some power stations in South Africa. This practice was aimed at using the fly ash to capture most of the elements in brine. However, the geochemical partitioning of the major elements in the waste materials after the fly ash-brine interaction has not been fully understood. This study focuses on understanding the geochemical partitioning of the major elements captured in the fly ash solid residues after the fly ash-brine interaction experiment. XRF and sequential extraction procedure were respectively applied to determine the chemical composition and partitioning of the major elements in fresh fly ash and the solid residues recovered after fly ash-brine interaction. The comparison of the results of the XRF analysis carried out on the fresh fly ash and the solid residues showed that the major elements such as Si, Ca, Mg and Na increased in the solid residues after the fly ash-brine interaction. This indicates that Ca, Mg and Na in the brine solution were captured by the fly ash during the interaction. However, the sequential extraction results showed that significant concentrations of Ca, Na and Mg were released into the water soluble, exchangeable and carbonate fractions. The results show that significant amounts of the elements captured in the fly ash solid residues during fly ash-brine interaction exist in the form which can be easily leached out when in contact with aqueous solution

Geophysical assessment of subsurface conditions at proposed building sites: implications for foundation failure and building collapse

Building collapse has been a recurrent environmental hazard in Nigeria in the last two decades. This is a corollary of inadequate foundation investigation prior to construction, poor government policies, and general lack of awareness on the importance of geophysical and geotechnical investigations. In this study, geological mapping and detailed geophysical investigation using Electrical Resistivity Imaging (ERI) and Vertical Electrical Sounding (VES) were carried out to understand the suitability of proposed building sites at the main campus of the Olabisi Onabanjo University (OOU), Ago-Iwoye, Nigeria for construction. Both Wenner array and dipole-dipole were used for profiling and Schlumberger for sounding. Four transverses and VES were used in each of the three areas investigated. Our results show that the subsurface of the study areas is underlain by Precambrian basement rock of Nigeria. Rocks in the study area include banded gneiss, porphyroblastic gneiss, biotite-hornblende granite and quartzite schist. The sounding stations across the three areas and 2D resistivity imaging revealed three principal geoelectric layers, the topsoil, the weathered layer and the fractured/fresh basement with varied resistivity values for each layers. At the VES stations, the three geoelectric layers have resistivity values of 62 to 1182 Ωm, 3.2 to 1360Ωm and 87 to 4680 Ωm. On the 2D resistivity imaging profiles, the resistivity of the three layers varies from 2 to 1182 Ωm, 30to 1360 Ωm, and 40 to 2904 Ωm for the topsoil, the weathered basement, and fractured/fresh bedrock. Our work demonstrates that some of the proposed sites are structurally incompetent for engineering or foundation purposes. Excavation of the topsoil and reinforcement are required to sustain the proposed structures

Effects of Petroleum Products on the Chlorophyll Accumulation in Barbula lambarenensis

The effects of petroleum products: Petroleum Motor Spirit (petrol, PMS), Automobile Gas Oil (diesel. AGO), Dual Purpose Kero (kerosene, DPK), were investigated on the chlorophyll accumulation in Barbula lambarenensis. This plant with its substrates were collected from its natural populations, taken to the screen house and divided into ten regimes widely separated. Each of these regimes was irrigated with borehole water for two weeks, thrice a week to bring about hydration. The three petroleum products were separately diluted with borehole water in 1:1 ratio to give 50% concentrations. Moreover, 100% of these products were also used .The 50% concentrations were separately used to irrigate the first three regimes, A, B and C for 20 weeks .The D, E and F regimes were irrigated with 100% kerosene, petrol and diesel respectively for the 2 weeks and later with borehole water for twenty weeks while the G regime was irrigated with borehole water (Control). Irrigations were done thrice a week. Samples of B. lambarenensis were collected fortnightly for chlorophyll extraction and the chlorophyll a, b and total chlorophyll content determined with the aid of spectrophotometer .It was observed that the 50% treated moss plants had greater chlorophyll a, b and total chlorophyll than the control but their concentrations were statistically the same. The 100% treatment gave greater chlorophyll a content than the control, PMS treatment had greater chlorophyll b than the control but the reverse were for DPK and AGO treated moss plant. However, all these values were the same statistically. The same results were found for the total chlorophyll except that the DPK, AGO and Control treatments had the same value statistically while DPK, Control and PMS treatments were the same statistically. The 50% treatments had worse effects than the 100% followed by borehole water treatments. Furthermore, the two concentrations had the same effects on the chlorophyll contents but DPK and AGO had significantly greater chlorophyll b concentrations in 50% treated regimes than 100% treatments at 5% level of significance. Petroleum products damaged the chlorophyll apparatus of the plant making the treated to produce greater chlorophyll contents than the Control

Biocidal Activities of Some Tropical Moss Extracts Against Maize Stem Borers

Solutions of four moss powders, namely: Calymperes afzelii Sw., Thuidium gratum (P. Beauv.) Jaeg., Bryum coronatum Schwaegr. and Barbula lambarenensis (Hook) Spreng., were evaluated for insecticidal activity against maize stem borers. The aqueous solutions were smeared periodically on mature maize plants in the field. All mosses tested showed some toxic activity against the established maize stem borers, deterrence regarding further infestation and some influence on the distribution of the borers. C. afzelii and B. coronatum showed encouraging toxic activities, deterrent activities and promptness that were better or just as good as with Tricel, the control inorganic insecticide. The order of activity of the moss solutions was C. afzelii\u3e B. coronatum \u3eT. gratum= B. lambarenensis. The incidence of stem borer in the most preferred internode, i.e. III, was reduced significantly by C. afzelii, T. gratum and B. coronatum treatments, while B. lambarenensis like, Tricel, restricted the incidence of borer holes to internodes III and IV. The advantages proffered by the window of utilizing mosses as pesticide, namely: availability, safety, low cost, ease of application, as well as, the disadvantages, i.e. laborious serial repetitions, was highlighted

Synthesis and characterization of carbon doped TiO2 photocatalysts supported on stainless steel mesh by sol-gel method

This study synthesized pure anatase carbon doped TiO2 photocatalysts supported on a stainless steel mesh using a sol-gel solution of 8% polyacrylonitrile (PAN)/dimethylformamide (DMF)/TiCl4. The influence of the pyrolysis temperature and holding time on the morphological characteristics, particle sizes and surface area of the prepared catalyst was investigated. The prepared catalysts were characterized by several analytical methods: high resolution scanning electron microscopy (HRSEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), and X-ray photoelectron spectroscopy (XPS). The XRD patterns showed that the supported TiO2 nanocrystals are typically anatase, polycrystalline and body-centered tetragonal in structure. The EDS and XPS results complemented one another and confirmed the presence of carbon species in or on the TiO2 layer, and the XPS data suggested the substitution of titanium in TiO2 by carbon. Instead of using calcination, PAN pyrolysis was used to control the carbon content, and the mesoporosity was tailored by the applied temperature. The supported TiO2 nanocrystals prepared by pyrolysis at 300, 350, and 400°C for 3 h on a stainless steel mesh were actual supported carbon doped TiO2 nanocrystals. Thus, PAN/DMF/TiCl4 offers a facile, robust sol-gel related route for preparing supported carbon doped TiO2 nanocomposites.IS

Mobility and Transport of Inorganic Species in Weathered Hydraulic Disposed Coal Fly Ash: An Insight from Geochemical Fractionation and Statistical Evaluation

A large volume of coal fly ash generated through combustion process has raised environmental concerns due to possible release of potentially toxic species to the surface and groundwater systems. The chemical partitioning and mobility of elements in the hydraulic disposed ash dump was investigated using modified sequential extraction scheme. The geochemical distribution of the investigated elements in 33 drilled core samples was determined by x-ray fluorescence and inductively coupled plasma mass spectrometry. The ternary plot of major elements as determined by XRF showed that hydraulic disposed ash cores are sialic, ferrosialic and ferrocalsialic in chemical composition. The relationship between SiO2 and chemical index of alteration (CIA) showed low, moderate to high degree of weathering. These chemical compositions and degree of chemical weathering depend on the ash sampling point and ash interaction chemistry. The Na+ and K+ soluble salts showed evidence of leaching and downward migration in the water soluble fraction indicating that the hydraulic disposed ash dump is not a sustainable salt sink. The geochemical partitioning reveals that mobility and transport of potentially toxic metal species are governed by the pore water pH, ash interaction chemistry and the sampling point of the ash cores.  The chemical interaction of drilled core ash with the ingress CO2 and percolating rain water led to dissolution and co-precipitation of soluble major components in fly ash. This had led to incoherent patterns of elements in carbonate fraction of the ash cores.Key words: Modified sequential extraction; Hydraulic disposed ash; Chemical index of alteration; Pore water pH; Ash interaction chemistry; Moisture content; Chemical weatherin