Cyanide Content Research Articles

Evaluation of the Contribution of Cassava Staple to the Recommended Dietary Allowance of Selected Nutrients Among the under Five Children in Mtwara Rural District, Tanzania

This study aimed at evaluating the contribution of cassava recipe in meeting Recommended Dietary Allowance (RDA) of the under five children for the selected nutrients (protein, fat, iron and zinc) in Mtwara rural district. This was achieved by identifying the common cassava recipes and the consumption pattern by using a 24h dietary recall and Food Frequency Questionnaire (FFQ). Proximate composition, mineral contents and anti-nutrients (cyanide and phytate contents) were also determined. The rate of consumption of a child was computed based on food portion and consumption frequency in a day. The sufficiency of nutrient of cassava recipes was determined on the basis of the quantity of food eaten per day. Computed nutrient intake was evaluated against the RDA of respective nutrient for respective age category. The findings indicate that the contribution of cassava to the RDAs of the respective nutrients were 19.4% for iron, 21% for zinc, 0.527% for fat and 4.26% for protein among the under five children which is extremely low. The anti-nutrient (phytate) content was far above the tolerable level of 25 mg/100g but cyanide was within the acceptable level. The computed Individual Dietary Diversity Score (IDDS) of 2.5 was similarly far below the target IDDS of 5. This implies an extremely poor dietary diversity indicative of very low consumption of food varieties including those of animal origin. It is thus important to develop strategies which encourage and make easy for dietary diversification among community members in order to complement cassava based recipes with readily available foods rich in macro and micronutrients. The strategy should also consider dietary practices such as control of intake of inhibitors e.g. of iron absorption and increase intake of enhancers of absorption in a given meal. These strategies can also include cassava recipe supplementation and fortification.

Effect of types and concentrations of auxins on callus induction and primary somatic embryogenesis in low cyanide cassava cultivars ( <i>Manihot esculentum</i> Cranz)

Cassava constitutes a greater part of the diet of most Africans south of the Sahara and the demand for the crops has been on a steady increase. Agriculturally, cassava performs very well, but the roots and leaves contain cyanogenic glycosides that are dangerous to human health. As such, cassava cultivars with low cyanide content offer great opportunities for domestic and industrial utilization. However the major constraints to the production of low cyanide cassava cultivar are susceptibility to diseases such as cassava mosaic virus (CMV) and non-availability of disease free planting materials. Application of biotechnology such as plant tissue culture could have a significant impact in the production large amount disease free planting materials. The effects of 2, 4-D and Picloram on callus induction and primary somatic embryogenesis in the low cyanide cassava varieties was evaluated. The result indicated a significant increase in percentage callus induction with increase in the concentration of 2, 4-D with 4mg/L producing the highest callus induction frequency of 72.21%. Similarly on media supplemented with Picloram, 7mg/L produced the highest callus induction frequency (73.11%) and frequency decreases with corresponding decrease in Picloram concentration. For the formation of somatic embryos, the result indicated a significant increase in number of primary embryos with increase in the concentrations of 2, 4-D or Picloram. This protocol presents a reproducible system for generation totipotent culture that could be used in genetic improvement of cassava and mass production of disease-free planting materials. Keywords : Cassava, Auxin, Callogenesis, Somatic embryogenesis

A novel dendritic polymer based turn- off fluorescence sensor for the selective detection of cyanide ion in aqueous medium

Porphyrin cored polyepichlorohydrin (POR-PECH) dendritic polymer was identified as an efficient turn-off fluorescence probe for selective determination of cyanide ion in aqueous medium. The dendritic polymer showed strong red fluorescence at 656 and 718 nm which was quenched in the presence of cyanide ion. POR-PECH showed high selectivity towards cyanide ion over other relevant anions including Cl−, Br−, F−, I−, NO2−, NO3−, CH3COO−, SO32−, CO32−, SCN−, HCO3−, HPO42−, H2PO4− etc. The proposed sensor is highly selective, sensitive which showed quick response towards cyanide ion. The limit of detection of proposed method was found to be 1.2 μM which was admirably lower than the maximum allowed cyanide content in drinking water (1.9 μM) as recommended by WHO. Back folding of self assembled porphyrin cored PECH dendritic chains by the addition of cyanide ion caused the quenching of fluorescence. The time resolved fluorescence life time, FE-SEM image and DFT studies supported the quenching mechanism.

Proximate composition, cyanide contents, and particle size distribution of cassava flour from cassava varieties in Zambia

The utilisation of cassava in the food industry is on the rise in Africa. However, information about the quality traits of raw material derived from new cassava varieties is limited. Cassava flours processed from six cassava varieties (Bangweulu, Katobamputa, Mweru, Kariba, Kampolombo and Chila) were assessed for particle size distribution, dry matter, starch yields; proximate contents, cyanides and whiteness index. The variety effect was analysed. The moisture, protein, lipid, ash, and fibre contents were in the range 10.43–11.18, 1.21–1.87, 0.15–0.63, 1.21–1.78, and 0.03–0.60%, respectively. The average particle size distribution at D90 (250.44–334.34 μm) and D10 (35.56–48.52 μm) varied (p < 0.05) among varieties. The bulk and packed density ranged 0.40–0.47 and 0.62–0.67 g/cm3, respectively. Bulk density correlated positively (p < 0.05) with moisture content. The cassava root dry matter contents varied in the range 40.04–47.25%, and correlated negatively with lipid (p < 0.01), ash content (p < 0.05) and positively with fibre (p < 0.01). Starch yield ranged between 20.76 and 28.31%. The cassava cyanide contents were in the range 23.60–238.12 and 8.62–15.48 mg HCN/kg for roots and flours, respectively. The cyanide reduction was in the range 60.76–93.86%. Degrees of lightness (L*) were in the range between 93.65 and 94.55, yellowness (b*) 6.52–8.15 with greenness in the range −0.03 to 0.44. The whiteness index of flours was in the range 89.90 to 91.46. Whiteness index negatively correlated with fibre content (p < 0.01). The quality traits varied among the cassava varieties, and source of variations were due to differences in flour particle size, fibre and ash contents.

Analysis of Leachate of Soil Water Pollution Using Geo-electrical Methods in Final Processing Place (TPA) Regional Sarbagita

A research about analysis of leachate of soil water pollution using geo-electrical methods in final processing place (TPA) regional sarbagita has been conducted. The measurements were made on 4 tracks by using a Naniura NDR 300HF resistivity meter. The results show on track 1 and track 2 indicate there is a leachate with a resistivity value ranging from 2.67 to 5.74 ?m and 3.15 to 9.19 ?m respectively, on track 3 indicate that the distribution of leachate has decreased compared to paths 1 and 2, on the 3 leachate path there are only certain points with resistivity values ranging from 6.57 to 9.66 ?m. Measurement results on track 4 the resistivity is greater than 10 ?m, this indicates that on track 4 there is no leachate pollution. The results of the analysis of well water samples which are located right on tracks indicating the content of BOD (biochemical oxygen demand), COD (chemical oxygen demand), Cyanide (CN), Lead (Pb), E. coli and coliform which exceeded the quality standard limits.

Application of Chitosan as Cyanide Adsorbance on Gold Ore Processing

&lt;p&gt;Gold ore processing method have an impact on water pollution if the waste produced is not managed properly. Chitosan have the ability as an adsorbent, but its effectiveness to absorb cyanide content in gold processing wastewater is unknown. This study aimed to examine the ability of chitosan adsorption on cyanide in the processing of gold ore. The statistic design used was a factorial in-time Completely Randomized Design (CRD) with two repetitions. The analysis carried out consisted of the effect of chitosan concentration on absorbance, pH, TDS, turbidity, cyanide, and the modification effect of chitosan production on absorbance power. The method used in this research was flocculation coagulation method by the jar test.The method was carried out by rapid and slow mixing process with a flocullator. The method was used to determine the best of chitosan type and the best contact time to decrease the concentration of cyanide waste from the processing of gold ore. The results showed that the best concentration of chitosan modified was chitosan modification with swelling crosslink glutaraldehid (GA) in 1000 ppm concentration and using slow mixing contact time for 120 minutes. That chitosan modified significantly adsorp cyanide waste in 90.38%.&lt;/p&gt;

Improvement of Cassava Bagasse Flour Characteristics To Increase Their Potential Use as Food

Efforts to increase the potential utilization of cassava bagasse (tapioca industrial by-product) as food can be done by improving its appearance (colour and odour), increasing protein content, and decreasing HCN levels. The aim of this research was to apply the abrasion peeling method and fermentation process using Saccharomyces cerevisiae in powder form to improve the characteristics of the cassava bagasse flour. The study was prepared in a Completely Randomized Block Design with 2 factors. The first factor was peeling method with two levels: washing method and abrasion method; the second factor was fermentation time with four levels, i.e. 1 day, 2 days, 3 days, and 4 days. The results research showed that the treatment of abrasion method and 4-days fermentation was the best treatment which will produce the cassava bagasse flour with protein content as 6.98%, cyanide content as 8.87%, whiteness degree as 52,70%, odour score as 5.95, starch content as 46.69%, dietary fiber as 23.13% and fat content as 0.95%. Compared to the cassava bagasse flour produced by the small-scale tapioca industry, the cassava bagasse flour of this research had a better white degree (52.70 versus 31.50), higher protein content (6.98% versus 0.92%), lower cyanide content (4.67 ppm versus 30.52 ppm), and a better odor score (5.95 versus 4.50). Improved appearance, increased protein content, and decreased cyanide content through improved peeling methods and the application of fermentation processes will increase the potential use of cassava bagasse as food.

Cyanide analysis based on complexing of CN− ion and spectrophotometry method

Cyanide analysis based on the complexing of CN− with Ni2+ ions by UV-Vis spectrophotometry has been performed. This study aims to obtain the maximum wavelength of cyanide-nickel absorption complexes, optimum conditions and UV-Vis spectrophotometric validation. The reaction between the green Ni2+ ion and the colorless CN− ion occurs in the solution to form a yellow [Ni(CN)4]2- complex, the maximum absorption is obtained at a wavelength of 308 nm. The optimum condition of [Ni(CN)4]2- complex gave at pH 6 and the concentration of Ni2+ solution of 0.001 M at a cyanide concentration of 0.004 M, while the optimum time formed by the complex occurred in 110 minutes and the complex compound was stable for 1390 minutes (± 23 hours 10 minutes). Validation of cyanide analysis method using Ni2+ ion gives linear regression equation y = 47,446x - 0,0184 with value R2 = 0,9958 at concentration range CN− 0.0003 M to 0.008 M; LOD 0.0006 M; % RSD = 0.97%; And % recovery = 103.8%. Based on the validation results, this method can be used to determine the cyanide content using Ni2+ ions as complexes by UV-Vis spectrophotometry.

English

Cyanide is a very toxic substance, which occurs in various forms in environmental matrices and its determination requires a good extraction method. From the reference method of cyanide distillation by reflux heating under acidic conditions and entrainment of HCN gas collected as CN- ions with detection by UV-Visible spectrophotometry, an improved and complete procedure for total cyanide extraction in aqueous and solid matrices has been developed. The best conditions after optimization of complete recovery (≃ 100%) of total cyanide and elimination of interferences in natural waters and soils fortified are: heating at 181.75°C, saving of reflux time to 30 min, sulfuric acid concentration of 0.6 M, 2 to 4 times less acid, without catalyst and other special treatments of interferences relatively to existing techniques. Application to water samples (drinking, surface, underground) and effluents collected at the Samira gold mine (Niger) and its environs shows the impact of distillation extraction on total cyanide recovery. Waters, exempt of cyanide at the starting of mining activity, currently contain total cyanide contents of 1 to 5 μg L-1 and in effluents up to 37 times the discharge standard (1 mg L-1). Key words: Cyanide decomposition, distillation extraction, environmental matrices, Samira gold mine (Niger).

Physicochemical properties of novel non-gluten cookies from fermented cassava root

In this study, novel cookies were prepared from cassava root fermented for 24, 48, 72 and 96 hr. The proximate composition, colour and functional properties of the flour and the chemical composition of the cookies, physical and sensory properties were assessed. Wheat flour had considerably higher protein (16.30%) than the unfermented (4.25%) and fermented cassava flour (5.51%–5.95%). The cyanide contents of flours (0.98–1.48 mg/kg) and cookies (0.41–1.29 mg/kg) are within the WHO recommended safe levels of 10 mg/kg. Cookies appearance and hardness were influenced by flour composition. Hardness of the cookies reduced with fermentation period and was substantially lower than wheat cookies. Sensory attributes of the cassava cookies were not significantly affected by fermentation generally except the aroma. Future studies are required to improve the aroma and taste of the cookies using food grade additives as panel members described the cookies from fermented cassava root as chalky. Practical applications This paper describes a novel way of producing non-gluten cookies using flour from fermented cassava roots. The results demonstrated that cookies with superior appearance and comparable quality can be made from fermented cassava flour. This result further provides another avenue for increased utilization of cassava roots through value addition.

Evaluation of fermented cassava (Manihot esculenta) peel meal on the growth of Clarias gariepinus

An experiment was conducted to evaluate the impact of cassava (Manihot esculenta, (NR 8082) peel, fermented with wastewater from the fermented cassava pulp, as a substitute for maize in the diet of C. gariepinus juveniles on the growth performance of C. gariepinus. Five iso-caloric and iso-nitrogenous diets were formulated containing 25%, 50%, 75% and 100% maize replacement with cassava peel meal (tagged diets B25, C50, D75, E100). The control was tagged diet A0. Two sets of experiment were designed using the formulated diets. One set, which lasted for 10 days, was designed to monitor the apparent protein digestibility of the diet and the second one to evaluate the growth, nutrient utilization (MWG, FCR, SGR) and the biochemical composition of the fillets of the fish, fed for a period of 8 weeks, in the laboratory. Fermentation significantly reduced (p&lt; 0.05) the phytate (698 mg 100g-1) and cyanide contents (23.5 mg kg-1) of the cassava peels, when compared with those of the unfermented cassava peels (1012 mg 100g-1, 44.6 mg kg-1). The final weight gain (13.47g), daily weight gain (0.19g), percentage weight gain (243.62%), food conversion ratio (5.67), protein efficiency ratio (1.20) and the apparent protein digestibility (APD) of the fish fed with the control diet (diet A0) were not significantly (P&gt;0.05) higher than those of the fish fed diets B25 and C50, but were significantly (P&lt;0.05) higher than those of the fish fed diets D75 and E100. The specific growth rate and survival in all the treatments were not significantly different (P&gt;0.05) from one another. The results revealed that 50% replacement of maize with cassava peel meal (diet C50) can be tolerated by C. gariepinus, without compromising growth, nutrient utilization and digestibility. The percentage survival of the fish fed the control, test diets B25, C50 and D75 were not significantly different (p&gt;0.05) but were significantly different from those fish fed diet E100. It can be concluded that replacing maize with up to 50% replacement level of cassava peels fermented with wastewater from the fermented cassava pulp is not deleterious to growth and nutrient utilization of C. gariepinus. Fermentation might have thus reduced the toxicity and increased the nutrient value of the cassava peels, otherwise regarded as agricultural wastes, and placed it among basal feedstuffs, suitable for replacing maize in C. gariepinus diet.

Effects of Solid-State Fermentation and the Potential Use of Cassava By-products as Fermented Food

By-products such as cassava bagasse and leaves are discarded though they contain high amounts of carbohydrates, proteins, fat and minerals. The application of solid-state fermentation (SSF) to substrates containing these by-products could improve the bioavailability of nutrients while reducing the amounts of anti-nutritive factors such as cyanide. To evaluate the possibility of using by-products from cassava some techniques, such as colorimetric methods, gas chromatography and high performance of liquid chromatography were applied to evaluate the total cyanide, carbohydrate contents, to characterize the fatty acid profiles, and estimate the essential amino acids after the fermentation process. After the SSF process, the cyanide content was significantly decreased. The profile of essential amino acids showed high concentrations of histidine, isoleucine, valine, methionine and phenylalanine. Some important unsaturated fatty acids were found, such as linoleic acid (18:29,12); α-linolenic acid (18:39,12,15); 11-eicosenoic acid (20:1) and 13,16-docosadienoic acid (22:2). The evaluation of the protein quality showed a significant increase in its bioavailability. The results support the conclusion that currently not used agricultural by-products could become sources of food that provide important quantities of essential nutrients.

Impact of indiscriminate disposal of untreated effluents in Korangi creek, Karachi, Pakistan

Korangi creek is one of the major creek of Indus delta which receives both untreated industrial and domestic effluents. It provides an important waterway to approach Port Qasim. A survey of water quality and the sediments along with biodiversity of benthic fauna was conducted. A total of 24 water and 14 sediment samples were collected from February to November 2014. The mean pH of seawater and sediment samples was 7.41 and 7.5, respectively. The mean salinity of seawater was 36‰. The mean BOD5 of seawater and sediments was 288 mg/l and 1645 mg/kg, respectively, while COD was 1231.9 mg/l and 1645.3 mg/kg, respectively. Cyanide content was low in seawater but slightly higher in sediment. Mean phenol level of seawater and sediment was 0.61 mg/l and 8.11 mg/kg. Heavy metals in the seawater was established to be in the order Pb > Cu > Cr > Ni > Zn > As. The trend in sediment was slightly different and followed the following pattern Pb > As > Ni > Cu > Cr > Zn. The distribution pattern of the estimated variables for seawater and sediments was examined using the principal component analysis and cluster analysis. Annelida and Arthropoda were the dominant components of biodiversity. Taxa diversity was measured and Shannon index (H) ranged between 1.364 and 1.969 while equitability (J) ranged between 0.549 and 0.862. Dominance (D) was in the range of 0.156–0.436.

POTENTIOMETRIC STUDY FOR RAPID CONTINUOUS MONITORING OF TRACE LEVEL THIOCYANATE USING SOLID AND CONVENTIONAL TYPES PVC MEMBRANE SENSORS

A comparative study using two different thiocyanate electrode designs was conducted; a solid type electrode (type A) and conventional liquid inner contact called electrode (type B). The fabrication of these electrodes was based on Al (III) [4-(2-Pyridylazo) resorcinol] (Al/PAR) and Mg (II) phthalocyanine (MgPC) complexes as a charged carrier,aliquate 336S and TDMAC as ion exchangers in plasticized poly (vinyl chloride) membrane. Electrodes type (A) revealed significantly enhanced response towards SCN - ions with displayed near-Nernstian slope of -53.7-55.8 mV decade -1 over the concentration range 5.0x10 -6 -1.0x10 -2 mol L -1 and a detection limit of 0.4-3.7 µg mL -1 . Type (B) sensors revealed near-Nernstian potential response to SCN - with a slope of -45.9-62.4 mV decade -1 over a linear range of 5.0x10 -5 - 1.0x10 -2 mol L -1 and a detection limit of 0.12-0.3 µg mL -1 . Membrane sensors based on (Al/PAR) and (MgPC) using the so called fixed interference method (FIM) exhibited a good selectivity over different anions which differ significantly from the classical Hofmeister series. All sensors were integrated in a flow system for continuous monitoring of thiocyanate under hydrodynamic mode of opration. The sensors revealed a frequency of ~ 54 samples h -1 . Application of the proposed sensors for SCN - determination in biological fluid samples such as saliva and urine collected from some non-smokers and smokers donors. Determination of cyanide content in electroplating wastewater samples after its conversion into thiocyanate was also applied. The results obtained from the proposed sensors were agreed with that obtained using the standard methods of thiocyanate and cyanide analysis.

Analysis of Cyanide Content on Yams Using Spectrophotometry Methods

This study aims to determine whether or not cyanide content in various species of yams in the District of Tempel, Sleman, Yogyakarta. The samples were cassava (Manihot esculenta Crantz), water yam (Discorea Alata), intoxicating yam (Dioscorea hispida Dennst), canna lilly (Canna discolor L), and taro (Colocasia esculenta). The qualitative test was performed by cementing the sample with aquadest and 10% tartrate acid and then covering the erlenmeyer that containing the sample with dry filter paper immersed in saturated picric acid and dampened with 8% sodium carbonate and then heating it. Quantitative tests were performed using a spectrum 20 with a wavelength of 590 nm. This quantitative test is based on forming a blue hydrindantin complex at pH 12 when cyanide is reacted with a ninhydrin complex. The results showed that in qualitative test, sample containing cyanide was indicated by the change of color of filter paper from yellow to brownish red. Quantitative results show that cyanide contained in sample as varies levels. The cyanide levels through the various species of yams were 0.1098 mg / 100g for cassava 0.049 mg/100 g for water yam, 0.1394 mg/100g for intoxing yam, 0.0896 mg/100 g for canna lilly and 0.0680 mg / 100g for taro.

Effects of Iodine Agronomic Bio- fortification on selected Physiological Characteristics of Cassava in Calabar, Southeastern Nigeria

Field experiments were conducted between November 2011 and May 2014 at the Crop Science Teaching and Research Farm of the University of Calabar, (Southeastern rainforest agro-ecological zone of Nigeria) to determine the effectiveness of Iodine agronomic fortification of cassava. The field experiment was a 2x3x4 factorial experiment arranged in randomized complete block design replicated three times, conducted using two cassava varieties,( TME 419 and TMS 30555); four iodine rates( 0, 2.5, 5.0 and 10.0) kg/ha KI; applied at 8, 10 and 12 WAP. Physiological data were obtained by determination of Iodine content [in cassava tuber]; tuber cyanide content (HCN); Carbohydrate content of tuber; starch content of tuber and tuber protein contents. Iodine absorption and retention in cassava tuber flesh was significantly positively correlated with Iodine doses at the times of application (p0.05 and 0.01). TME 419 retained more Iodine in tissues than TMS 30555 and recorded highest correlation co-efficient at 10WAP. Iodine doses and time of application did not significantly control (P≥0.05) contents of cyanide, carbohydrate and starch in cassava tubers. Protein content was significantly varied in cassava varieties and rate and time of Iodine application influenced tuber protein content. TME 419 produced more tuber protein, Iodine doses of 2.5kg/ha KI and 0kg/ha KI had higher protein content than 5kg and 10kg/ha KI. Application at 8WAP and 10WAP were not significantly different. For favourable physiological cassava characteristics, 2.5kg/ha KI is recommended applied 10 weeks after planting (WAP).

Analisis Kadar Sianida Pada Rebung Berdasarkan Volume Ukuran Dari Kecamatan Bajeng Kabupaten Gowa

Bamboo shoots are young shoots from bamboo Terubus. Bamboo shoots contain cyanide if consumed can cause shortness of breath, decreased blood pressure, rapid pulse, headache, nausea, diarrhea, mental disorders and seizures. Continuous consumption with low doses causes mumps and dwarfism and neurological diseases. This study aims to determine how much cyanide levels in bamboo shoots and this type of research is a descriptive laboratory experiment. The sample used in this study were 3 samples based on the size of the volume. The sampling technique is by means of purposive sampling that is looking at the criteria based on large, medium and small size types. Analysis of cyanide levels was obtained by UV-Vis Spectrophotometer with a wavelength of 582 nm. The results showed that large size bamboo shoots were height = 27 cm; diameter = 16 cm has a cyanide content of 21.84 mg/kg, medium size were height = 18 cm; diameter = 7 cm has a cyanide content of 18.40 mg / kg and a small size of height = 8 cm; diameter = 4 cm has cyanide content of 4.65 mg/kg. Thus it can be concluded that the greater the size of bamboo shoots have height level of cyanide.

Exiguobacterium aurantiacum mediated fermentation of bamboo shoot, and process optimization for Soibum production: A traditional food of Manipur, North-East India

Bamboo shoot are an important traditional food delicacies which are consumed as fresh, fermented, or canned in many Asian countries and is intricately related with human diet. In this study, several bamboo shoot samples (fermented and succulent bamboo shoots) were collected to determine the cynogenic glycoside content, followed by process optimization by using Exiguobacteruim aurantiacum FB6-1b, which was used for fermentation at different conditions. E. aurantiacum was isolated from bamboo shoot. The cyanide content was analyzed and fermentation process was also evaluated by estimating nutritional parameters of final product. Fresh succulent bamboo shoot had high cyanide content (approx 43 mg/g) compared with fermented samples (22.8–30.4 mg/g). It was observed that boiling the succulent bamboo shoots and fermented shoots removed all the cyanide content. The amount of protein, sugar, amino acid for fermentation of sterilized bamboo shoot with FB6-1b, against fermentation in presence of indigenous bacteria in raw bamboo shoot were found to be (2.2±0.6, 1.3±0.04, 0.38±0.004) mg/g and (2.44±0.03, 1.85±0.3, 0.31±0.006) mg/g, respectively. The nutritional parameter including concentrations of protein, sugar, amino acid were better when fermentation was done at temp 30°C (3.56±0.04, 11.1±0.2, 0.75±0.05 g/100g, respectively) and inoculum size 104 cfu/ml (2.57±0.1, 10.5±0.1, 0.27±0.04 g/100g, respectively).

Detoxification of ferrocyanide in asoil-plant system.

The detoxification of iron cyanide in a soil-plant system was investigated to assess the total cyanide extracted from contaminated soil and allocated in the leaf tissue of willow trees (Salix caprea). They were grown in soil containing up to 1000 mg/kg dry weight (dw) of cyanide (CN), added as 15N-labeled potassium ferrocyanide and prepared with a new method for synthesis of labeled iron cyanides. CN content and 15N enrichment were monitored weekly over the exposure in leaf tissue of different age. The 15N enrichment in the young and old leaf tissue reached up to 15.197‰ and 9063‰, respectively; it increased significantly over the exposure and with increasing exposure concentrations (p < 0.05). Although the CN accumulation in the old leaf tissue was higher, compared to the young leaf tissue (p < 0.05), the 15N enrichment in the two tissue types did not differ statistically. This indicates a non-uniform CN accumulation but a uniform 15N allocation throughout the leaf mass. Significant differences were detected between the measured CN content and the C15N content, calculated from the 15N enrichment (p < 0.05), revealing a significant CN fraction within the leaf tissue, which could not be detected as ionic CN. The application of labeled iron CN clearly shows that CN is detoxified during uptake by the willows. However, these results do not exclude other detoxification pathways, not related to the trees. Still, they are strongly indicative of the central role the trees played in CN removal and detoxification under the experimental conditions.

"Estimation of Potential Cassava Mill Effluents Discharged into Nigerian Environment "

Most food processing effluents are discharged into the environment with little or no treatment. Nigeria is the largest cassava producing nation. Cassava processing is majorly carried out by smallholder processors especially in Southern Nigeria. The effluents generated in the dewatering zone are lethal to lives probably due to the acidic and/ or cyanide content. This study estimated the quantity of cassava mill effluents that is often discharged into the environment during gari production. Projections based on growth scenarios viz: current, low and high growth rates were made. Cassava production historical data (literature reviews/ secondary data) for Nigeria were used for the study. Results revealed that 57.134 million tons of cassava was produced in 2016 leading to release of about 5.142 million tonnes of cassava mill effluents. Projections showed that before 2035, Nigeria may likely produce at high, low and current status growth rate 79.544, 73.850 and 57.719 million tons of cassava leading to the release of 7.158, 6.646 and 5.194 million tonnes of cassava mill effluents, respectively. After considering the challenges of gathering cassava mill effluents in Nigeria, only 45-65% of total effluents generated could be gathered for large scale utilization. Cassava mill effluents has demonstrated positive effect for utilization through biotechnological advances including biogas, bio-ethanol, bioelectricity (energy), animal feed, enzymes, bio-surfactant, organic acids among other. Hence there is the need for more research into these areas for optimization and possibly commercialization to avoid the attendant environmental impacts associated with the effluents.