Toxicity of non-selective herbicide-Paraeforce® to Periwinkle snail Tympanotonus fuscatus var radula

Periwinkle snails Tympanotonus fuscatus var radula, an important shellfish in the Niger Delta ecological zone are on the decline and they have not been considered in environmental risk assessment due to the lack of standardized protocols. The gastropod is an abundant species and widely distributed in the aquatic Niger Delta environments. In this study T. fuscatus var radula was exposed to ParaeForce(e), a solution of paraquat dichloride, a non-selective commonly used organochlorine herbicide due to it sensitivity to chemical compounds, as pollution indicators. The effect of lethal and sub lethal exposure of ParaeForce® was assessed using the Organization for Economic Development and Cooperation (OECD) #218 protocol to determine the toxicity and safe limit concentrations. The lethal exposure gave an average LC50 of 0.665 mg/kg with a safe limit of 0.0665 mg/kg. The sub lethal test showed that the exposed organisms reduced significantly in body mass at levels of P < 0.05 when compared to the control experiment. Mean percent growth rate relative to the control reduced from 100% to 47% while the highest growth inhibition of 53% was observed in the highest concentration. Thus, the release of the test chemical and other similar herbicides into the environment may cause alteration and loss of body mass in periwinkle molluscs due to their toxic potentials. It is important to exercise caution in the application of this herbicide especially in the aquatic environment for weed control

Bioactive profiling and therapeutic potential of mushroom (Pleurotus tuberregium) extract on Wistar albino rats (Ratus norvegicus) exposed to arsenic and chromium toxicity

Mushroom species are valued in gourmet traditions around the world for their unique taste, aroma, nutritional value and medicinal potentials. The bioactive profiling of P. tuberregium mushroom was evaluated to determine it therapeutic effect on Wistar albino rats exposed to arsenic (As) and chromium (Cr) toxicity. Proximate analysis of P. tuberregium showed high composition of carbohydrate (80.24) followed by moisture (21.16), protein (11.46), ash (3.03) and fibre (0.25) content. Phytochemical analysis revealed the presence of polyphenols (2.58), alkaloid (2.46), oxalate (4.25), flavonoid (1.68), tannin (0.38) and Saponin (trace) in trace amount. Mineral analysis yielded variable amounts of Na, Mg, K and Ca. Therapeutics assessment of P. tuberregium to Wistar albino rats exposed to As-Cr toxicity showed improved feed and water intake during the exposure duration. Haematological indices revealed significant increase in platelet (PLT), granulocytes and monocytes while lymphocyte (LY) and red cell distribution width (RDW) were low. Biochemical and redox marker of liver and kidney profiles showed decrease in alkaline phosphatase (ALP), alanine transaminase (ALT) and aspartate transaminase (AST) in the liver. Creatinine and urea in the kidney also decrease while total protein increased significantly. Malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD), glutathione S-transferase (GST) decrease in the liver and kidney of the therapeutic group when compared with As-Cr treated rats. The presence of alkaloids and flavonoids in significant amount may have contributed in the therapeutic changes observed in all the parameters. Therefore, our findings conclude that P. tuberregium possessed remarkable effect against As-Cr induced toxicity in albino rats and may be useful in metal toxicity treatment in man and may be concluded that they are therapeutically effective. Keywords: Arsenic, Chromium, Pleurotus tuberregium, Haematological and redox marker

Impacts of acute exposure of industrial chemicals and pesticides on the survival of fish (Tilapia guineensis) and earthworms (Aporrectodea longa)

Ecotoxicological effects of industrial chemicals (Rig wash, Oil eater, Nalco, Glycol™) and pesticides (Propoxur, Deltamethrin, Atrazine, Furadan) on Tilapia guineensis (fish) and Aporrectodea longa (earthworms) were tested using the Organisation for Economic Cooperation and Development (OECD) # 203 and 207 protocols. The water and soil ratings indicate that the test chemicals were toxic to the organisms. The estimated 96 hour lethal concentration LC50 values for Rig wash, Oil eater, Nalco EC1304A/COT 505, Glycol, Propoxur, and Deltamethrin were 26.34±0.46, 6.02±0.30, 3.07±0.14, 1.31±0.01, 20.91±0 and 0.01±0 mg/l respectively. In the earthworm bioassay, the estimated 14-day LC50 values for Rigwash, Oil eater, Nalco EC1304A/COT 505, Glycol, Atrazine and Furadan were 80.05±3.5, 151.55±10.7, 172.63±14.2, 63.72±2.43, 4.97±0 and 0.29±0 mg/kg respectively. Safety factors are arbitrarily built in around the LC50 values in order to arrive at environmentally tolerable concentrations. The concentration of a chemical in the receiving environment should not exceed 10% of the L50. The organisms exposed to the test chemicals showed significant difference when compared with the levels measured in the control group. The observed sensitivity of the test organisms to the chemicals indicates that adherence to standard safety limits/measures should be maintained during use and disposal of hazardous chemicals. This would ensure that the biotic components of the Nigerian Niger Delta ecosystem are prudently protected

Biochar-facilitated batch co-digestion of food waste and cattle rumen content: An assessment of process stability, kinetic studies, and pathogen fate

Anaerobic digestion is an established sustainable route for managing the organic fraction of municipal solid waste. The commonly adopted mono digestion of organic waste is often beset by many challenges chief of which is process instability. This study assessed the role of biochar in process stability and pathogen fate for batch co-digestion of food waste (FW) and cattle rumen content (CRC). Biochar had different functional groups, a large surface area (627.50 m2/g), and a pore volume (0.32 cm3/g). Biochar amendments helped stabilize the pH and reduce the accumulation of volatile fatty acids (VFAs) and total ammonia nitrogen (TAN). Biochar amendment using 5 g biochar also facilitated biogas production at low pH conditions (3.72 – 4.45), yielding a cumulative biogas yield of 706.11 ml/gVS with a biomethane composition of 64.3%. Pathogen counts revealed significant log reductions in the range 3.0–3.2 for E. coli, Bacillus, and Salmonella within the first 7 days of digestion, corresponding to 99.9% removal, indicating the safety of the resulting digestate for agricultural use. The modified Gompertz model adequately represented the kinetics of the anaerobic digestion process. The study has provided insights into biochar-facilitated digestion of CRC and FW for enhanced process stability

Anaerobic co-digestion of cattle rumen content and food waste for biogas production:Establishment of co-digestion ratios and kinetic studies

This study investigated the batch co-digestion of cattle rumen content (CRC) and food waste (FW) for biogas production in different ratios (CRC:FW) to assess biogas production and process stability. The results showed that CRC and FW possess characteristics that are desirable for biogas production as seen in their respective total solids (10.85 and 26.53%), volatile solids (89 and 86.83%) and carbon to nitrogen ratio (23.7 and 15.7) values. Co-digestion improved carbon to nitrogen ratio, biogas yield and pH of the co-substrate compared to individual substrates. The 50:50 co-digestion ratio was found to be optimum as it gave the maximum cumulative biogas yield of 320.52 ml/gVSadded. Co-digestion also improved the pH, volatile fatty acid (VFA) and total ammonia nitrogen (TAN) characteristics during digestion. The cone model was able to adequately represent the kinetics of the process. These findings have provided very useful insights into the co-digestion of CRC and FW