Capability of biowaste composite of high density polythene with egg shell and wood sawdust for sorption of heavy metals in industrial waste water

ABSTRACT: The health hazards posed by heavy metals in water and the need to mitigate the hazards have attracted a flurry of research interests on the technologies and methods of removing them from water. The industrial waste water from a gutter within the neighbourhood of the Delta Shopping Mall in Effurun was used to test the heavy metal sorption capacity of the waste high density polythene and biowaste composites compounded by the author using a locally constructed extruder. Some of the physico ­ chemical properties of the waste water determined with PH Kent meter (model 7020) and Hach conductivity meter (C0150) where within WHO acceptable limits while some were not. The metal concentrations were determined using Atomic Absorption Spectrometer(Perkin Elmer Absorption Analyst 400 model) The Composite of 2:1.5:0.5 (HDPE: saw dust: egg shell) sorbed the highest concentration of the metals ( 0.168mg/L, Fe; 0.072mg/L, Ni and 0.082mg/L, Cr than the other composites of 1.5: 1: 1.5 and 2:1:1 except Cd while the composite, 2:1:1 sorbed the least concentration of metals( 0.061mg/L, Fe; 0.044mg/L, Ni; 0.071mg/L, Cr and 0.002mg/L, Cd during the first 24 hours of sorption exposure. Chromium was the most sorbed metal, 97.6% while cadmium was the least, 20.0%. There was no systematic pattern of variation for metal absorption in the next 24 hours due probably to the blocking of the pore sites during the first twenty four hours of sorption exposure. The composite, 2:1.5:0.5 exhibited a good potential as an economic heavy metal sorbent

Toxicity and Bioremediation of Heavy Metals Contaminated Ecosystem from Tannery Wastewater: A Review.

The discharge of untreated tannery wastewater containing biotoxic substances of heavy metals in the ecosystem is one of the most important environmental and health challenges in our society. Hence, there is a growing need for the development of novel, efficient, eco-friendly, and cost-effective approach for the remediation of inorganic metals (Cr, Hg, Cd, and Pb) released into the environment and to safeguard the ecosystem. In this regard, recent advances in microbes-base heavy metal have propelled bioremediation as a prospective alternative to conventional techniques. Heavy metals are nonbiodegradable and could be toxic to microbes. Several microorganisms have evolved to develop detoxification mechanisms to counter the toxic effects of these inorganic metals. This present review offers a critical evaluation of bioremediation capacity of microorganisms, especially in the context of environmental protection. Furthermore, this article discussed the biosorption capacity with respect to the use of bacteria, fungi, biofilm, algae, genetically engineered microbes, and immobilized microbial cell for the removal of heavy metals. The use of biofilm has showed synergetic effects with many fold increase in the removal of heavy metals as sustainable environmental technology in the near future.

Root surface conditioning with bone morphogenetic protein-2 facilitates cementum-like tissue deposition in beagle dogs.

BACKGROUND AND OBJECTIVE: Modification of the root surface may play an important role in regenerating the periodontal attachment between the root and periodontal connective tissue. We speculated that bone morphogenetic protein (BMP) application to the root surface constructed a novel attachment by cementum-like hard tissue, although gingival connective tissue proliferated to the root surface. The aim of this study was to examine whether BMP-2 guided cementum-like tissue deposition on a BMP-conditioned root surface. MATERIAL AND METHODS: Root dentin on the buccal side of 24 teeth in four beagle dogs was surgically exposed. The denuded root dentin surfaces were demineralized with EDTA and washed with saline. Subsequently, 15 microL of BMP-2 solution (loading dose, 0.4 and 1.0 microg/microL) was applied to the root dentin surface. In the control roots, phosphate-buffered saline was applied to the root surface. Specimens were analyzed histologically 16 wk after surgery. RESULTS: Formation of cementum-like tissue was frequently observed on the BMP-2-conditioned root at the coronal portion. Cellular cementum-like tissue was separated from the original cementum and encapsulated with gingival connective tissue. Cementum-like tissue formation with BMP-2 at 1.0 microg/microL was significantly greater than that in the control roots and those with BMP-2 at 0.4 microg/microL. Downgrowth of the junctional epithelium in the 1.0 microg/microL BMP-2 group was significantly less than that in the control roots. CONCLUSION: Root dentin surface conditioning with BMP-2 stimulated cementum-like tissue formation and inhibited epithelial downgrowth.

The impact of handpump corrosion on water quality in rural areas of West African sub-region.

Water, even in its natural environment, contains some level of impurities. Water is nearly a universal solvent. It contains dissolved solids and gases, and hosts a number of micro-organisms. The exploitation of groundwater by means of boreholes for supplying small user groups and rural communities with water has been widely applied in certain parts of the world for several decades. In recent years this practice has spread all over the globe, and hundred of thousands of boreholes have been drilled to tap low-yield aquifers. It is evident that such boreholes require pumps for lifting the water. In developing countries these are usually handpumps, but solar as well as other systems with submersible pumps are also used, depending upon the energy sources available and the financial means of the beneficiaries. This article gives a general overview of groundwater quality with regard to its physico-chemical composition. The results presented originate from the experience gained from handpump equipped boreholes within the UNICEF through German Centre for Technical Education Transfer executed inter-regional UNDP-Handpumps Project in West African Regions. Particular attention is paid to presenting corrosion on the water quality of wells in terms of iron concentration and other parameters. Furthermore, the corrosion attack on galvanised iron, the effect of biofilms on the corrosion rate, and the difference between internal and external corrosion of rising mains are shown.

An appraisal of subsurface geology and groundwater resources of Owerri and environs based on electrical resistivity survey and borehole data evaluation.

The research was aimed at determining the depth to the water table, aquifer thickness and subsurface geology of the study area thus revealing its groundwater distribution as well as its potential as a substitute to the surface water resources. Vertical electrical soundings were carried out in the study area with maximum electrode spread. The Schlumberger electrode configuration technique was adopted. VES data were processed using Schlumberger analysis package. Lithologic logs of already existing boreholes in the study area were collected, evaluated and comparison were carried out. The results reveal alternating layers of sands, sandstones, gravel and clay. The lithologic logs revealed that the study area is underlain by coastal sands (Benin formation). The water table varies from 10-64 m and thickness of the aquifer ranges from 20-80 m. Results show that the study area is underlain by a thick extensive aquifer that has a transmissivity of 2.8 x 10(-2) m2 s(-1) to 3.3 x 10(-1) m2 s(-1) and storativity 1.44 x 10(-4) to 1.68 x 10(-3) m s(-1) values. The specific yield is about 0.31. The sandy component of the study area forms more than 90% of the sequence, therefore the permeability, the transmissivity and the storage coefficient are high with an excellent source of groundwater resources.

Critical control points of complementary food preparation and handling in eastern Nigeria.

OBJECTIVE: To investigate microbial contamination and critical control points (CCPs) in the preparation and handling of complementary foods in 120 households in Imo state, Nigeria. METHODS: The Hazard Analysis Critical Control Point (HACCP) approach was used to investigate processes and procedures that contributed to microbial contamination, growth and survival, and to identify points where controls could be applied to prevent or eliminate these microbiological hazards or reduce them to acceptable levels. Food samples were collected and tested microbiologically at different stages of preparation and handling. FINDINGS: During cooking, all foods attained temperatures capable of destroying vegetative forms of food-borne pathogens. However, the risk of contamination increased by storage of food at ambient temperature, by using insufficiently high temperatures to reheat the food, and by adding contaminated ingredients such as dried ground crayfish and soybean powder at stages where no further heat treatment was applied. The purchasing of contaminated raw foodstuffs and ingredients, particularly raw akamu, from vendors in open markets is also a CCP. CONCLUSION: Although an unsafe environment poses many hazards for children's food, the hygienic quality of prepared food can be assured if basic food safety principles are observed. When many factors contribute to food contamination, identification of CCPs becomes particularly important and can facilitate appropriate targeting of resources and prevention efforts.

Assessment of ground water vulnerability and its application to the development of protection strategy for the water supply aquifer in Owerri, Southeastern Nigeria.

Pollution vulnerability of the Owerri regional water supply aquifer was evaluated as a basis for developing appropriate protection strategy for the groundwater resource. The assessment was accomplished using Legrand, GOD, Siga and DRASTIC models. Techniques of the models generally involved parameters rating and point count systems, which are based on the evaluation of various parameter in relation to their capacity for enhancing or attenuating contaminants in the groundwater system. Field and laboratory evaluations of the parameters indicate that the Owerri area generally occupies a nearly, flat topography with a relatively high groundwater recharge. The area is underlain by predominantly sandy facies in the Northern area which grades into gravelly sequences towards the southwest. The Southeastern area is distinguished by thick clayey facies that thin westwards towards the Owerri metropolis. Effective hydraulic conductivity (Kz) in the downward direction ranges from 1.44 x 10(-3) to 5.6 x 10(-9) m s(-1); with the upper limits reflecting coarse sands and gravelly units. The amount of clay and clay-size particles in the sandy and gravelly units is negligible, suggesting that the sorptive capacity of the units is low. Depth to water table decreases southwards while hydraulic head gradients vary between 0.09 and 0.22. Groundwater occurs in unconfined conditions in most places except in the southeastern zone where it is semi-confined due to the presence of a clayey unit. The groundwater vulnerability map developed on the basis of the models and several other thematic maps shows that the Owerri metropolis and the southwest area of Owerri have high vulnerability, indicating groundwater pollution. The existing waste disposal sites in these sub-areas should be abandoned and rehabilitated to forstall further pollution of the groundwater system. Areas to the North and Southeast of Owerri have moderate and low vulnerabilities, respectively, indicating the relatively lower sensitivity of the groundwater system in the sub-areas to contamination. The lower sensitivity could further be matched with properly engineered sanitary landfills in the event of choice of sites, as an additional protective strategy for the groundwater system.

Natural fluoride levels in some springs and streams from the late Maastrichtian Ajali formation in Ohafia-Arochukwu area of south eastern Nigeria.

The aim of this study was to provide baseline data on the fluoride levels in waters associated with the late Maastrichtian Ajali formation in Ohafia-Arochukwu area of South Eastern Nigeria. Water samples from 14 artesian, perched springs and eight streams from the formation were collected with plastic containers. Fluoride analysis was carried out with inductively coupled plasma Atomic Emission Spectrometry (ICP-AES) equipment at the laboratories of the Department of Earth Science, University of Leeds, United Kingdom. The results showed that fluoride occurred in only one of the 14 spring water samples. Fluoride level in the sample was 0.03 ppm. The spring water, which contained some fluoride, was possibly associated with another rock formation: namely, the limestone bearing Nsukka formation, which overlies the Ajali formation. No fluoride was observed in all the stream water samples. This study reported the absence of fluoride in spring and stream waters associated with the late Maastrichtian formations in Nigeria.

Effects of enzyme induction, renal and cardiac function on ketamine plasma kinetics in patients with ketamine long-term analgosedation.

Steady-state plasma levels of ketamine and its metabolites norketamine and dehydronorketamine were determined in 4 different groups of a total of 27 patients with ketamine long-term analgosedation (1.1 - 1.3 mg/kg/h). In 9 of the patients who had normal liver and kidney function (group 1), steady-state levels after 3 days of continuous infusion were 1.2 +/- 0.3 micrograms/ml ketamine, 1.0 +/- 0.6 micrograms/ml norketamine, and 2.6 +/- 1.0 micrograms/ml dehydronorketamine. The measured ketamine levels in group 1 were in agreement with the expected value, which may be calculated from published pharmacokinetic data after bolus injection. In 8 patients with acute renal failure (group 2), a tendency to about 20% higher ketamine steady-state plasma levels compared to group 1 was observed, but this difference was not significant. However, dehydronorketamine plasma levels were significantly higher in this group. Only a minor fraction of the ketamine dose (10% and 4%) was eliminated during hemodialysis or hemofiltration treatment, respectively. Steady-state plasma levels in 5 patients with cardiogenic shock (group 3) did not differ significantly from those of group 1. In 5 patients with long-term use of barbiturates (group 4), steady-state plasma levels of ketamine were significantly lower compared to groups 1 and 3, most likely due to barbiturate-induced enzyme induction. Hyperdynamic circulatory reactions were not observed in any of the patients. Psychomimetic effects could be excluded in 16 of the patients and were unlikely in 6 patients. In 5 further patients, psychomimetic effects could not definitely be excluded due to difficulties in non-verbal communication.

Suicidal ingestion of formalin with fatal complications.

After ingestion of an unknown amount of formalin with suicidal intent, a 55-year-old female and a 34-year-old male were admitted to the hospital with extensive gastrointestinal corrosive damage, circulatory shock, metabolic acidosis, respiratory insufficiency and impairment of renal function, which rapidly progressed to acute renal failure. Metabolic acidosis was in part due to high plasma levels of formic acid, the main metabolite of formaldehyde, and hyperlactatemia. Both patients underwent hemodialysis and hemofiltration treatment. In the male patient, a gastrectomy had to be performed. The further clinical course in the patients was characterized by sepsis and protracted pulmonary complications. Both patients died after developing adult respiratory distress syndrome and global cardiac insufficiency. In vitro experiments on formaldehyde reactivity to proteins yielded evidence for almost complete but reversible binding to plasma and blood. Formaldehyde probably exerts systemic toxicity in the form of its labile Schiff's base with proteins, but not as free formaldehyde.

Clinical experience with the benzodiazepine antagonist flumazenil in suspected benzodiazepine or ethanol poisoning.

The clinical efficacy of different doses of the specific benzodiazepine antagonist flumazenil was studied in a total of 72 patients with benzodiazepine or ethanol overdose. In a randomized double-blind study, 18 patients (group 1) and eight patients (group 2) with suspected benzodiazepine overdose received 5 mg (group 1) or 1 mg (group 2) flumazenil or placebo, respectively. The stage of coma, heart rate, blood pressure and respiratory rate were monitored within the following 15 min. If no change in the stage of coma was observed, 5 mg (group 1) or 1 mg (group 2) flumazenil were given, and the stage of coma, heart rate and blood pressure were again monitored. In a similar way, the effect of 5 and 1 mg flumazenil was investigated in 13 patients (group 3) and four patients (group 4) with ethanol intoxication. In an open trial, the clinical efficacy of flumazenil for the diagnosis of benzodiazepine or ethanol overdose was studied in 29 patients (group 5). In all patients, a toxicological screening confirmed benzodiazepine or ethanol overdose. None of the patients receiving placebo showed effects on stage of coma, heart rate, blood pressure or respiratory rate. Patients with benzodiazepine overdose who received 5 mg flumazenil regained consciousness about 1-2 min after the end of injection. The effect of 1 mg flumazenil (group 2) on benzodiazepine-induced coma was less pronounced. In patients with ethanol overdose (group 3), ethanol-induced coma was reversed after 5 mg flumazenil more slowly than in patients of group 1. No effect of flumazenil on ethanol-induced coma was observed in group 4. In group 5, flumazenil proved to be useful for diagnosing benzodiazepine or ethanol intoxication. In one patient with coma due to carbamazepine overdose, flumazenil was also found to be effective. Additionally, a possible analytical interference of flumazenil and its metabolites with the identification of other benzodiazepines by a toxicological screening procedure was studied. Even after an oral dose of 200 mg flumazenil, no interference with immunological benzodiazepine assays (EMIT, TDX, and RIA) was found. A metabolite and an artifact of flumazenil could be identified in urine by gas chromatography/mass spectrometry.

Enzyme catalytic concentrations in human plasma after a marathon.

Blood was obtained from 11 males participating in the Berlin marathon 1986, directly before and after the marathon, and on the three following days. Several observations were made: a) catalytic concentrations (activity) of creatine kinase (CK), lactate dehydrogenase (LDH), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (AP) increased directly after the marathon or on the three following days; b) Cholinesterase (CHE), amylase (AML) and gamma glutamyltransferase (GGT) decreased directly after the marathon; c) the time course of AP and LDH isoenzyme activity after the race indicated an elimination from plasma to lower values than those originally observed before the run.

[Corrosive burns of the upper gastrointestinal tract in adults]. / Verätzungen des oberen Gastrointestinaltraktes beim Erwachsenen.

Experience obtained from acid burns in 60 adult patients is reported in this paper. Twelve of them died, while 48 received conservative treatment, and twelve underwent surgery. Attempted suicide accounted for the highest number and severity of those accidental injuries. The therapeutic approach should be chosen on earliest possible endoscopy. Trends towards exploratory laparotomy and blind oesophagus stripping are described, and the problem of conservative therapy is discussed.

Hemoperfusion in acute camphor poisoning.

After ingestion of an unknown dose of a 10% camphor spirit (maximum dose 200 ml), a 54-year-old female was found in coma, having developed grand-mal-like seizures and respiratory failure. For detoxification, gastric lavage and hemoperfusion with amberlite XAD4 were performed. During hemoperfusion, seizures ceased, but no marked influence on the clinical course of the intoxication--especially on grade of coma--was observed. For further evaluation of the efficacy of treatment, camphor plasma elimination kinetics during hemoperfusion were compared to plasma elimination kinetics determined in a volunteer after an oral dose of 200 mg of camphor. Although the plasma compartment was almost completely (89%-95%) cleared of camphor by hemoperfusion, only a total of 35 mg of camphor was removed due to its high apparent volume of distribution (estimated 2-4 l/kg). The plasma elimination half-life was not affected by hemoperfusion, which may be explained by the saturation of metabolizing enzymes, still incomplete absorption, or metabolic interference of isopropanol. In the case presented here, neither the clinical course of the intoxication nor plasma level data gave evidence for a pronounced beneficial effect of hemoperfusion.

Acute trichloroethylene poisoning with additional ingestion of ethanol--concentrations of trichloroethylene and its metabolites during hyperventilation therapy.

One hour after suicidal ingestion of about 150 g of trichloroethylene, a 32-year-old male was admitted to hospital. On admission, the patient's state of consciousness deteriorated from somnolence to coma. Based on blood level data, an absorbed trichloroethylene dose of at least 35 g was estimated. Additionally, ethanol, which is a strong inhibitor of trichloroethylene metabolism, had been ingested. With respect to the high dose of trichloroethylene, hyperventilation therapy was performed for 28 h. Concentrations of trichloroethylene and its metabolites in blood and urine were determined by gas chromatography. Due to hyperventilation and inhibition of trichloroethylene metabolism, not more than 30% of the absorbed dose was metabolized and excreted via kidneys. Under normal respiratory conditions and in the absence of ethanol, this fraction amounts to about 75%. Obviously, hyperventilation and ethanol-induced inhibition of metabolism led to considerably enforced pulmonary elimination of the absorbed trichloroethylene.

Inadvertent metal loading of critically ill patients with acute renal failure by human albumin solution infusion therapy.

Recent reports on the metal contamination of human albumin solutions (HAS) have raised concern about possible medical implications. Large amounts of HAS are infused to premature babies with respiratory distress syndrome, patients with plasmapheresis treatment or acute renal failure. For assessment of the risk of metal loading in patients with acute renal failure, commercially available HAS were analyzed for aluminium, nickel, chromium, manganese, cobalt, zinc, copper, cadmium, lead, and mercury. A considerable contamination of HAS was found for Al, Ni, Cr, Mn, and in part for Co. Additionally, the influence of 3 weeks of daily HAS infusion on metal blood levels was studied in 8 critically ill patients with acute renal failure, protein catabolism, ventilator therapy and hemodialysis treatment. Since most metals are primarily eliminated with the urine, these patients seemed to be at high risk for metal loading. In all patients, a considerable increase in the blood concentrations of Al, Ni, Cr, and in some patients of Mn and Co was found. In addition, the daily dose of Al, Ni, Cr, Mn, and Co by HAS was calculated for the 21st day after start of HAS infusion. In most patients, the dose of Al, Ni, and Cr considerably exceeded (up to a factor of 10) the average daily metal dose absorbed from the diet by healthy subjects. The increase in Mn and Co blood levels, despite a low dose of Mn and Co with the daily HAS infusion, was most likely caused by depletion of Mn and Co tissue stores due to the catabolic state of the patients. The contamination of HAS probably originated from the use of aluminum hydroxide and from contact of plasma with stainless steel surfaces during the Cohn fractionation process. The high extent of contamination of HAS with Al, Ni and Cr cannot be accepted since it is already technically feasible to produce HAS with metal concentrations comparable to the normal serum level range.

Urinary metabolism of dextromethorphan in man.

After an oral dose of 50 mg of (+)-3-methoxy-N-methylmorphinan (dextromethorphan) to volunteers, urinary metabolism was studied by gas chromatography/mass spectrometry. A total of 15 previously unknown metabolites and derivatives of dextromethorphan could be identified by mass spectrometric techniques. The main metabolic pathways were: O,N-demethylation, O,N-acetylation, hydroxylation of the phenyl ring and the saturated ring system with subsequent further oxidation.

Poisoning with over-the-counter doxylamine preparations: an evaluation of 109 cases.

One hundred and nine cases of monointoxication with doxylamine were evaluated with respect to age distribution, amount ingested, plasma level, and clinical symptomatology. The age of 60% of the patients ranged between 16 and 30 years. In about 60% of the cases 10 to 40 times a single therapeutic dose (25 mg) was ingested. Doxylamine plasma concentrations exceeded the maximum plasma level after a therapeutic dose by a factor of 10 to 40 in two-thirds of cases. The most frequent symptoms included impaired consciousness, seizures, tachycardia, mydriasis and a 'psychosis' similar to that in catatonic stupor. A serious complication may be rhabdomyolysis with subsequent impairment of renal function and acute renal failure. No symptoms were observed in 39% of the patients. No correlation was found between the amount ingested or doxylamine plasma level and the clinical symptomatology. Primary detoxication included gastric lavage, administration of activated charcoal and sodium sulfate. Regarding the high frequency of doxylamine overdose and its possible complications the question arises as to whether doxylamine-containing preparations should be subjected to prescription.