Total Cyanide Research Articles

Cyanogenesis in Macadamia and Direct Analysis of Hydrogen Cyanide in Macadamia Flowers, Leaves, Husks, and Nuts Using Selected Ion Flow Tube-Mass Spectrometry.

Macadamia has increasing commercial importance in the food, cosmetics, and pharmaceutical industries. However, the toxic compound hydrogen cyanide (HCN) released from the hydrolysis of cyanogenic compounds in Macadamia causes a safety risk. In this study, optimum conditions for the maximum release of HCN from Macadamia were evaluated. Direct headspace analysis of HCN above Macadamia plant parts (flower, leaves, nuts, and husks) was carried out using selected ion flow tube–mass spectrometry (SIFT-MS). The cyanogenic glycoside dhurrin and total cyanide in the extracts were analyzed using HPLC-MS and UV–vis spectrophotometer, respectively. HCN released in the headspace was at a maximum when Macadamia samples were treated with pH 7 buffer solution and heated at 50 °C for 60 min. Correspondingly, treatment of Macadamia samples under these conditions resulted in 93–100% removal of dhurrin and 81–91% removal of total cyanide in the sample extracts. Hydrolysis of cyanogenic glucosides followed a first-order reaction with respect to HCN production where cyanogenesis is principally induced by pH changes initiating enzymatic hydrolysis rather than thermally induced reactions. The effective processing of different Macadamia plant parts is important and beneficial for the safe production and utilization of Macadamia-based products.

Application and Mechanism of Sludge-Based Activated Carbon for Phenol and Cyanide Removal from Bio-Treated Effluent of Coking Wastewater

The toxic pollutants phenol and cyanide in the bio-treated effluent of coking wastewater still need advanced treatment to meet environmental requirements. In this study, activated carbon prepared from municipal sludge and bamboo waste (SBAC) was used for simultaneous adsorption of phenol and cyanide from bio-treated effluent of coking wastewater. The results showed that the optimum removal efficiencies of volatile phenol (69.7%) and total cyanide (80.1%) were observed at a SBAC dosage of 8 g/L, a pH value of 8.0, and a contact time of 80 min. The physical and chemical properties of SBAC were analyzed using Brunauer–Emmett–Teller (BET) surface area (SBET), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopy. SBAC had high SBET (289.58 m2/g) and rich mesoporous structure (average pore diameter of 3.688 nm), and carboxylic groups on SBAC surfaces were enhanced due to the addition of bamboo waste. In addition, a kinetic model of pseudo-first-order fitted well with the experimental data of volatile phenol, while the adsorption of total cyanide onto the SBAC was better described by a pseudo-second-order kinetic model.

Mineralization of cyanide originating from gold leaching effluent using electro-oxidation: multi-objective optimization and kinetic study

This study examines the electro-oxidation (EO) of cyanide originating from an industrial plant´s gold leaching effluent. Experiments were carried out in a laboratory-scale batch cell reactor. Monopolar configuration of electrodes consisting of graphite (anode) and aluminum (cathode) was employed, operating in galvanostatic mode. Response Surface Methodology (RSM), based on a Box–Behnken experimental Design (BBD), was used to optimize the EO operational conditions. Three independent process variables were considered: initial cyanide concentration ([CN−]0 = 1000–2000 mg L−1), current density (J =7–107 mA cm−2), and stirring velocity (η = 250–750 rpm). The cyanide conversion $$\left( {X_{{{\text{CN}}^{ - } }} } \right)$$, Chemical Oxygen Demand (COD) removal percentage (%RCOD), and specific Energy Consumption per unit mass of removed cyanide (EC) were analyzed as response variables. Multi-objective optimization let to establish the most effective EO conditions ([CN−]0 = 1000 mg L−1, J = 100 mA cm−2 and η = 750 rpm). The experimental data ($$X_{{{\text{CN}}^{ - } }}$$, %RCOD, and EC) were fitted to second-order polynomial models with adjusted correlation coefficients ($$R_{\text{adj}}^{2}$$) of ca. 98, 99 and 87%, respectively. The kinetic analysis, performed at optimal EO operational conditions, allowed determination of time required to meet Colombian permissible discharge limits. The predictive capacity of kinetic expressions was verified against experimental data obtained for gold leaching effluent. Total cyanide removal and 96% of COD reduction were obtained, requiring EC of 71.33 kWh kg−1 and 180 min. The BOD5 (biological oxygen demand)/COD ratio increased from 4.52 × 10−4 to 0.5573, confirming effluent biodegradability after EO treatment. The variation of cyanide (CN−), cyanate (CNO−) and ammonium (NH4+) ions concentrations vs. time at alkaline conditions. EO operational conditions: [CN−]0 = 1000 mg/L, J = 100 mA/cm2 , η = 750 rpm, [NaCl] = 0.15 M and pH 11.1.

Stabilization of Prussian blue using copper sulfate for eliminating radioactive cesium from a high pH solution and seawater

Prussian blue (PB), an adsorbent for the selective elimination of radioactive cesium from water, is highly versatile due to its unique crystal structure. However, PB crystals quickly decompose in an alkaline solution, generating hazardous cyanide contamination. In this research, the alkaline susceptibility of PB was remedied by incorporating copper sulfate as a protector. A stability assessment was conducted at several environmental conditions, such as high pH and temperatures from 10 °C to 50 °C, in seawater, artificial seawater, and river water. The crystalline and chemical stability of PB in the new class of composite was extremely high, even at a pH value of 11.2, as confirmed using XRD and total cyanide analysis. A comprehensive mechanism study revealed that, at high pH, the copper ions that cover the PB react with hydroxide ions to form copper hydroxide and shielding inner crystals. To decontaminate radioactive cesium, the first step was to immobilize nano PB on a cellulose nanofiber, followed by copper sulfate stabilization. Then, a spongiform adsorbent was made using polyurethane as the precursor. The new stabilized PB showed promising adsorption efficiency. Thus, this research will open a new range of applications for all existing and emerging PB-based adsorbents.

Physicochemical Characteristics and In Vitro Starch Digestibility of Spontaneously Combined Submerged and Solid State Fermented Cassava (Manihot esculenta Crantz) Flour

Background: High cyanide varieties of cassava must be detoxified before consumption. Several studies showed detoxification of cassava by slicing, submerged fermentation (soaking), solid state fermentation, and drying. One of traditional detoxification is combination of submerged and solid state fermentation and the effect of this processing on cyanide reduction and food properties has not been evaluation yet. Objective: This research studied the effect of solid state fermentation time on physicochemical, starch granule morphology, and in vitro starch digestibility of cassava flour from high cyanide varieties of Malang 4, Malang 6, and Sembung. Methods: Three varieties of high cyanide grated cassavas were soaked for 3 days in ratio of water to cassava 1:1. After draining for 1 hour, grated cassava was placed in a bamboo container and put in a humid place for 3-day solid state fermentation. Fermented grated cassavas were then dried, milled, and analyzed. Results: Solid state fermentation similarly affected cyanide reduction and characteristics of cassava flour for three high cyanide varieties. The detoxification process reduced cyanide to 89.70-93.42% and produced flour with a total cyanide of 8.25-10.89 mg HCN eq/kg dry matters, which is safe to consume. Fermentation decreased cyanide, starch content, titratable acidity, swelling power, and solubility; meanwhile pH, amylose content, water absorption, oil absorption, and in vitro starch digestibility increased in all three varieties studied. Submerged fermentation reduced the pH thus inhibiting the degradation of linamarin and cyanohydrin into free HCN. pH value was increased by solid state fermentation, from 4.43 to 6.90 that optimum for linamarin and cyanohydrin degradation into free HCN. The submerged and solid-state fermentation indeuce spontaneous microbial growth that affected chemical composition of cassava flour. The changes of structure and morphology of starch granules affected pasting properties, and Increased in vitro starch digestibility due to damaged granules. Conclusion: Solid-state fermentation reduced cyanide content of all three cassava varieties into the safe level for consumption, and aiso changed chemical, physical, and functional characteristics and starch digestibility of cassava flour.

Cu adsorption behaviours onto chelating resins from glycine-cyanide solutions: Isotherms, kinetics and regeneration studies

A method is presented to remove and recover copper from copper-gold glycinate solutions using an iminodiacetic functionalized resin with subsequent regeneration. The adsorption/desorption approach was evaluated for a glycine leaching process which was shown to be effective for the dissolution of gold and copper from different gold-copper ores and concentrates. In this process, glycine is the lixiviant in the presence of very low cyanide concentration as a synergistic reagent. The copper species in glycine-cyanide process are mainly present as cupric glycinate and a low concentration of cuprous dicyanide and no free cyanide. While cupric glycinate does not load well onto activated carbon, cuprous dicyanide is problematic due to its high carbon affinity and co-loading with gold onto activated carbon, thereby requiring the removal of most of the copper prior to the gold recovery. In this study, the use of ion-exchange resins as one of the possible downstream recovery processes for gold and copper from glycine-cyanide solutions was tested. The isotherms and kinetics of gold and copper (cupric copper (Cu2+)) adsorb onto the chelating resin (Puromet MTS9300) from their alkaline glycinate and cyanide complexes were studied. Results show that the [CNT−]: [CuT] molar ratio has significant effects on the adsorption of CuT, due to the change in Cu2+/Cu+ ratio in the solutions, where [CN−T] is the total cyanide in the system (free cyanide being zero). The results show that the chelating resin is selectively adsorbed cupric (Cu2+) over cuprous (Cu+) ions. The adsorption results were fitted to both the Freundlich and Langmuir isotherm models, while the Langmuir model shows a better correlation. The adsorption kinetic data of Cu2+ is well fitted to the pseudo-second-order model. Alkaline glycine solutions in the presence of NaCl was selected as the main eluent for the resin elution study. The multi-cycle adsorption/desorption tests showed that the resin adsorption and regeneration efficiencies are not significantly changed after five cycles of adsorption/desorption. Microscopic visual analysis by using scanning electron microscopy (SEM) showed that there is no significant change in shape and size of the resins, although more cracks were observed after the 5 cycles of adsorption/desorption.

Photoelectrocatalytic degradation of Ag-cyanide complexes and synchronous recovery of metallic Ag driven by TiO2 nanorods array photoanode combined with titanium cathode.

A photoelectrocatalytic (PEC) system for the decomposition of Ag-cyanide complexes synchronously with Ag recovery was established using the titanium dioxide nanorods (TiO2 NRs) as photoanode and the titanium plate as cathode. The removal efficiency of total cyanide was 76.58%, and the recovery ratio of Ag achieved 84.48% at the applied bias potential of 1.0 V vs SCE in the PEC process. During the reaction, the surface variations and photo-electric properties of TiO2 NRs photoanode or titanium cathode were characterized by SEM-EDS, XPS, and photoelectronic analyses. It was indicated that Ag2O and metallic Ag were deposited onto the TiO2 NRs photoanode and titanium cathode, respectively. Specifically, the in situ generated Ag2O on the TiO2 NRs photoanode facilitated the separation of the photogenerated charge carriers and enhanced the visible-light response, thus improving its PEC catalytic activity toward cyanide destruction. Combined with the results of active species quenching experiments, the mechanism of Ag-cyanide complexes decomposition and metallic Ag recovery by the PEC process was proposed.

Thermal remediation of cyanide-contaminated soils：process optimization and mechanistic study

Site soils with persistent cyanide compounds (primarily iron-cyanide complex) pose potential hazards to the environment and require remediation before redevelopment. This study evaluated the possibility of thermal treatment on remediation of cyanide-contaminated soils via batch heating experiments spanning a wide temperature range (200–500 °C). The change with operation variables of total cyanide and some reaction intermediates (e.g. CN−) was analyzed in order to elucidate the optimal variables that guarantee cyanide removal while generating no hazardous byproducts. Temperature, heating time and cyanide species have been found to be important parameters influencing removal/destruction of cyanide in soils. For soils bearing K3[Fe(CN)6] and K4[Fe(CN)6], a removal efficiency of >99.9% can be obtained with temperatures over 350 °C at 1 h, while for samples bearing Fe4[Fe(CN)6]3, a higher temperature (>450 °C) is needed to obtain an equivalent efficiency. During heating, the iron-cyanide complexes decomposed, releasing highly toxic free cyanides, which will subsequently be oxidized. However, a small percentage of free cyanide can always be detected as a result of incomplete oxidation, thus caution should be taken to minimize the accumulation of free cyanide during thermal treatment.

Improving Nutrition, Physicochemical and Antioxidant Properties of Rice Noodles with Fiber and Protein-rich Fractions Derived from Cassava Leaves

Introduction: Noodles are rich in fibre and important nutrients which help promote health. This study was an attempt to determine the impacts of using different levels of cassava leaves on antioxidant features, nutritional values, and the quality of rice noodles. Methods: Wheat flour and rice were used to prepare rice noodles which used cassava leaves which were on the basis of flour weight (0, 10, 20, 30 and 40%). The proximate analysis, antioxidant activities, texture, color, and total cyanide content of the noodles were then determined. Results: The present findings suggest that using cassava leaves at different levels helps modify the structure of the noodles, finally leading to a softer product in comparison with the control samples. Furthermore, the addition of cassava leaves increased the amount of protein and fiber content and improved the antioxidant activities of rice noodles. Conclusion: It could be implied that cassava leaves with a lot of advantageous components -could be a great ingredient to enhance antioxidant features and nutritional value (protein and fiber) of noodle.

Influence of Coating Application Methods on the Postharvest Quality of Cassava.

Various modes of edible coating application vary in their coat dispersion and film formation, hence the need to determine the most effective mode of application for cassava. Edible surface coatings have been found to be effective in preserving the quality of various food products. However, there are variations in effectiveness among the different coating solutions, hence the need for optimization of the concentrations of the gums used. This study aimed at determining the most efficient coating application method on the cassava postharvest quality. Physiologically mature cassava (variety KME 1) was harvested and divided into seven portions. The various portions were coated using 1.5% xanthan gum, 1.5% xanthan/guar gum, and 2% xanthan/guar gum by both dipping and spraying method. There was no significant difference on the colour, total cyanide, ethylene production, and total phenolic content between the two application methods. The 2% xanthan/guar gum coating showed a significant difference on the dry matter content while the 1.5% xanthan gum coating had a significant difference on the respiration rate and weight loss. The 1.5 xanthan treated roots had a final dry matter content of 72.5% for the sprayed samples and 75.98% for the dipped sample while the 2% xanthan/guar gum treated roots had a final dry matter content of 64.6% and 74.1% for the dipped and sprayed root samples, respectively. The 1.5% xanthan and 2% xanthan/guar gum treated roots showed no significant difference in their action on dry matter content. The 1.5% xanthan/guar dipped and sprayed samples differed significantly on their effect on flesh firmness with final values of 35.4N and 46.1N, respectively, at 20 days after harvest. This study suggested that based on the coating solution and the parameters being observed, there generally was no varying effect of dipping and spraying methods of coating application. The choice of the efficient mode of application to use will depend on other factors such as the easiness of application.

Chemical root traits differentiate ‘bitter’ and ‘sweet’ cassava accessions from the Amazon

Abstract ‘Bitter’ and ‘sweet’ cassava are normally distinguished based on the hydrocyanic acid (HCN) content of their roots. Moreover, Brazilian farmers tend to select ‘sweet’ cassava based on the taste and cooking aspects. The aim of this study was to characterize chemical traits of ‘bitter’ and ‘sweet’ cassava roots of the Amazon region and to find genetic relations among accessions based on these traits. Considerable phenotypic variation was detected among the evaluated traits moisture, ashes, total soluble solids, total titratable acidity, pH, total carotenoids, free and total cyanide, crude protein, glucose, fructose, sucrose and starch. Aside from free and total cyanide, the trait means of sugars and moisture differed in ‘bitter’ and ‘sweet’ cassava and also differentiated these in different clusters in the dendrogram using the unweighted pair-group method based on arithmetic averages (UPGMA) and in the results of principal component analysis.

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).

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.

Bacterial Productivity in a Ferrocyanide-Contaminated Aquifer at a Nuclear Waste Site

This study examined potential microbial impacts of cyanide contamination in an aquifer affected by ferrocyanide disposal from nuclear waste processing at the US Department of Energy’s Hanford Site in south-eastern Washington State (USA). We examined bacterial productivity and microbial cell density in groundwater (GW) from wells with varying levels of recent and historical total cyanide concentrations. We used tritiated leucine (3H-Leu) uptake as a proxy for heterotrophic, aerobic bacterial productivity in the GW, and we measured cell density via nucleic acid staining followed by epifluorescence microscopy. Bacterial productivity varied widely, both among wells that had high historical and recent total cyanide (CN−) concentrations and among wells that had low total CN− values. Standing microbial biomass varied less, and was generally greater than that observed in a similar study of uranium-contaminated hyporheic-zone groundwater at the Hanford Site. Our results showed no correlation between 3H-Leu uptake and recent or historical cyanide concentrations in the wells, consistent with what is known about cyanide toxicity with respect to iron speciation. However, additional sampling of the CN− affected groundwater, both in space and time, would be needed to confirm that the CN− contamination is not affecting the GW biota.

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.

Certified Reference Material for Determination of Total Cyanide in Soil [BAM-U116/CGL306

CRM (Certified Reference Material) BAM-U116/CGL306 “Cyanide in soil” was produced within a framework of cooperation between CGL (Central Geological Laboratory) of Mongolia and Federal Institute for Materials Research and Testing (BAM) of Germany in 2013-2017. The CRM BAM-U116/CGL306 represents a mixture of a sandy soil collected from a contaminated former gasworks area in the Berlin region (Germany) and an unpolluted sandy soil from Nalaikh region (Mongolia). The bulk candidate material for this reference material was prepared at CGL CRM Laboratory exclusively destined to the preparation of reference materials and equipped with modern technical equipment. Homogeneity, stability and shelf life were studied in full compliance with ISO Guide 35. The CRM was evaluated as sufficiently homogeneous. Statistical evaluation of certification analysis was software packages SoftCRM and ProLab Plus. Certified value of total cyanide of the CRM is 12.0 mg/kg and expanded uncertainty was assigned as 0.8 mg/kg. The intended purpose of this material is the verification of analytical results obtained for the mass fraction of total cyanide in soils and soil-like materials applying the standardized procedure ISO 11262:2011. As any reference material, it can also be used for routine performance checks (quality control charts) or validation studies.

Effects of roasting conditions on physicochemical properties and antioxidant activities in Ginkgo biloba seeds.

The roasting treatment has been used to extend the shelf life of food and improves its quality, and eliminate or reduce toxic. In this study, we investigate the changes in the physicochemical properties and antioxidant activities of Ginkgo biloba seeds (GBS) according to the roasting temperature and duration. As the roasting temperature and duration increased, the pH (from 7.32 to 6.31) and total cyanide content (from 1.49 to 0.70µg/g) decreased, whereas the titratable acidity (from 0.39 to 0.84%) increased. The antioxidant activities increased rapidly at 210°C according to the increase in the roasting temperature and duration. The 4'-O-methylpyridoxine (MPN) content in the 210°C heat treatment group decreased by more than 70% compared to the MPN content in the control group. These results suggest that heat-treated GBS could be used in food materials and medicines for decreasing cyanide and MPN contents as well as for increasing antioxidant compound contents.

Assimilation of cyanide and cyano-derivatives by Pseudomonas pseudoalcaligenes CECT5344: from omic approaches to biotechnological applications

Mining, jewellery and metal-processing industries use cyanide for extracting gold and other valuable metals, generating large amounts of highly toxic wastewater. Biological treatments may be a clean alternative under the environmental point of view to the conventional physical or chemical processes used to remove cyanide and related compounds from these industrial effluents. Pseudomonas pseudoalcaligenes CECT5344 can grow under alkaline conditions using cyanide, cyanate or different nitriles as the sole nitrogen source, and is able to remove up to 12 mM total cyanide from a jewellery industry wastewater that contains cyanide free and complexed to metals. Complete genome sequencing of this bacterium has allowed the application of transcriptomic and proteomic techniques, providing a holistic view of the cyanide biodegradation process. The complex response to cyanide by the cyanotrophic bacterium P. pseudoalcaligenes CECT5344 and the potential biotechnological applications of this model organism in the bioremediation of cyanide-containing industrial residues are reviewed.

Utilization of Banana, Pineapple and Watermelon Wastes-Substrate: As Consortiums to Remediating Cyanide Polluted Soil

The act of processing cassava for varied food products has come with unguided and wide-spread contamination of cyanide in the environment. The need for effective reduction in cost to enable remediation of cyanide-contaminated sites from cassava mill factories is the purpose of this investigation. This involves bio-stimulation of organic wastes with indigenous microorganisms to degrade cyanide. The application of organic wastes as a substrate for the removal of cyanide was adopted. Banana, pineapple, and watermelon wastes were selected and bio-stimulated in cyanide contaminated soil. Each set-up containing 100 g of Cassava Mill Effluent (CME) contaminated soil was added with varied percent - 1, 5 and 10% of pineapple, banana, and watermelon waste, respectively. The monitoring of cyanide reduction was studied for 28 days. Periodic collection of soil samples from each set-up was done at four days interval to determine total cyanide concentration, total heterotrophic bacteria, and enzymes activities. Results indicated that after 28 days of applying the 10% watermelon, 5% pineapple and 1% banana waste, the 10% watermelon waste gave a better cyanide reduction compared to pineapple and watermelon waste treatment. The one phase-decay equation of 1% - banana, 5% - pineapple and 10% - watermelon waste treatment gave the shortest disintegration rate. The soil physicochemical properties, agro waste, microbial population, soil enzymes activities, soil microbial respirometric index, the bio-parameters sensitivity, carbon, nitrogen, and phosphorus were determined. The first order kinetics model revealed by the nth order algorithm; pineapple waste treated soil had the highest reduction rate - 0.9098/day of CME with half-life - 6.98 days. The 1% banana and 10% watermelon treated soil samples have the cyanide reduction rates - 0.9315/day and 0.8997/day. The cyanide reduction rate was significantly higher than the untreated contaminated CME (control) soil - 0.8975/day. The microbial counts and the three agrowaste treatment samples increase in day 4-16 (2.20×108 to 6.40×108 CFU/g) for 5% - pineapple; 1% - banana increased from 20×108 to 8.90×108 CFU/g (day 20 - 28) and 10% - banana increased -1.20×108 to 8.70×108 CFU/g (day 4-20); 1% - watermelon increased from 8.40×108 to 8.80×108 CFU/g (day 20-24) and 10% watermelon increased from -8.10×108 to 8.70×108 CFU/g (day 24-28), than the control which showed increase from 3.40×108–7.20×108 CFU/g (day 4-12) during the 28 days of remediation study. Soil organic carbon content gave a positive correlation with microbial biomass, carbon, nitrogen, and phosphorus, as well as microbial population, basal soil respiration and soil enzyme - catalase, lipase, dehydrogenase, urease and phosphatase activity. Soil contamination decreased (p<0.05) catalase, urease and dehydrogenase activities in all the waste treated soil compared to the control set-up. Owing to the use of this agro-waste-banana, pineapple and watermelon has proved to be effective in enhancing soil nutrient, improved soil enzymes activity and removed of cyanide from CME contaminated soil.

Cyanide Toxicity of Freshly Prepared Smoothies and Juices Frequently Consumed.

Aims:This study was conducted to detect the presence of cyanide in popular fruit and vegetable smoothies and juices marketed as raw and natural.Study Design:Eleven (11) popular varieties of drinks were analyzed for total cyanide (TCN). Drinks contained raw vegetables and fruits, flax seeds, whole apples with seeds, raw almond milk, and pasteurized almond milk as ingredients.Place and Study duration:Samples were collected from health food eateries located within Las Vegas, Nevada (USA) during the summer of 2017.Methodology:Fifty milliliters (mL) of a homogenized smoothie and juice drink and 1 gram of flax seeds were subjected to the above-referenced methods for sample preparation per USEPA Methods 9012B (digestion) followed by USEPA method 9014 (colorimetry).Results:The highest TCN was detected in drinks containing raw flax seed followed by unpasteurized raw almond milk, then fresh whole apple juice. No TCN was observed in drinks that contained none of the above mentioned items (e.g. flax seed, raw almond milk) or those utilizing pasteurized ingredients.Conclusion:This study observed that TCN is present in smoothies and juices containing raw flax seeds, fresh whole apples, and/or unpasteurized almond milk. Concentrations were detected as high as 341 μg L−1 in commercially available smoothies containing vegetables, raw flax seeds, almond milk and fruits. Smoothies with vegetables, fruits, unpasteurized almond milk, and no flax seeds contained 41 ug L−1 TCN, while similar smoothies with pasteurized almond milk contained negligible to 9.6 ug L−1 CN-. Unpasteurized almond milk and raw flax seeds were the major sources of TCN in drinks. With the increased demand for raw and natural foods, there is a potential sublethal exposure of TCN by consumers.