Remediation of contaminated marine sediment using bentonite, kaolin and sand as capping materials

There is a growing public concern over the issue of sediment contamination resulting from industrial, municipal wastewater, mining activities, and improper use of chemical fertilizer or pesticides. The conventional treatment of contaminated sediment is dredging, but this treatment is expensive and requires a large area of land for disposal. In situ capping of contaminated sediment is considered as a cheaper technique compared to dredging and efficient treatment technology to immobilize pollutants in sediments on site. In this technique, sediments are capped by placing a layer of inert materials like sand, clean soil, or gravel or active materials like activated carbon, zeolite, or apatite over sediments in order to reduce the risk to the aquatic environment. The objective of this study is to determine the effectiveness of using active materials; bentonite (B), kaolin (K), mixture of bentonite with kaolin (1:1) (BK) as capping materials to block the release of five heavy metals (Pb, Cr, Cu, Cd and Zn) from artificially polluted sediments. The effectiveness of B, K, and BK for preventing the leachability of the trace metals was assessed on a bench-scale laboratory experiment in glass tanks for 90 days, where 1cm thick layer of capping material and sand was placed above the contaminated sediment. The results showed that B and BK reduced the leachability of Pb, Cr, and Cu from the sediments. The results also showed that B and BK could be used as potential capping materials for the remediation of contaminated sites due to their significant entrapping of Pb, Cu, and Cr. The pollutants were released into the overlying water from the contaminated sediment in the following decreasing order; Cd > Zn > Pb > Cu > Cr. The adsorption kinetics analysis also showed that the process of adsorption was by chemisorption. This study proved that bentonite and mixture of bentonite with kaolin clays covered with sand could be used as capping materials for in situ treatment of Pb, Cu, Cr, Zn, and Cd for contaminated marine sediment

In Situ Capping Remediation of Contaminated Marine Sediment using Bentonite, Kaolin and Sand to Interrupt the Release of Trace Metals

 In situ capping remediation is a technique by which a capping material is placed on top of sediments to prevent continued contamination of surface water from the contaminated sediments. In this study Bentonite, Kaolin, Sand and mixture of Bentonite with Kaolin were used as capping materials. The objective of this study was to investigate the possibility of using Bentonite, kaolin, mixture of Bentonite with kaolin (1:1) and sand as capping materials to block the release of trace metals (Pb, Cd, Cr, Cu, and Zn) from the artificially contaminated marine sediments, A bench scale laboratory experiment in aquariums was performed for a period of 90 days where 1-cm-thick layer of capping materials was placed above the contaminated sediments. The average Pb concentration in control, capped with bentonite, kaolin, and mixture of both is 4.08, 0.77, 6.77and 0.84mg/l respectively, similarly for Cr is 5.63, 0.15, 5.63 and 0.29 mg/l respectively. The average concentration for Cu is 4.28, 0.145, 5.63 and 0.11mg/l respectively and also for Zn and Cd which are the most mobile is 68.81, 5.82, 75.56 and 23.46 mg/l and 58.35, 14.75, 59.97 and 39.8 mg/l respectively. The trace metals were released into the overlying water from the heavily contaminated sediments in the following decreasing order Cd > Zn > Cu > Pb > Cr. For the uncapped all the contaminants are constantly released with various kinetic depending of mineral oxidation or dissolution or leaching. The release did not go beyond 32 % of the initial pollutants in the sediments. Bentonite and its mixture with Kaolin have much higher metal adsorption capacity compared to that of only Kaolin. The results showed that the capping materials Bentonite and mixture of Bentonite with Kaolin were effective in interrupting the release of Pb, Cu and Cr throughout the experimental period but Cd and Zn were only captured from the beginning but later released gradually until completion. It was concluded that Bentonite and its mixture additive can be used as potential capping materials for the remediation of contaminated sites

Dietary supplement using cockroach meal: impact on growth indices and biochemical responses in hybrid catfish

Globally the need to substitute fishmeal with other animal protein sources in the fish diet has gained more attention; which is occasioned by the increasing cost of fish. A 12-week trial was conducted to ascertain the growth indices and biochemical response of hybrid catfish (Clarias gariepinus(♀) and Heterobranchus bidorsalis (♂)) fed cockroach meal supplement. A total of 800 hybrid catfish were randomly distributed into four dietary treatments (Diet A- control feed), Diet B (50 % cockroach and 50 % fishmeal), Diet C (100 % cockroach meal) and Diet D (100 % fishmeal). Each treatment was replicated with 35 fish per experimental pond in a completely randomized design. Progressive weight gain was determined bi-weekly. At the end of the study period, fishes were randomly sacrificed for proximate compositions and plasma biochemical analyses (glucose, triglyceride, cholesterol, total protein, albumin) using standard protocols. The study revealed that growth parameters (Weight gain, Average weight gain, Protein efficiency ratio, Feed Conversion rate, Specific growth rate and Survival rate (SR) were influenced by the dietary treatments (p>0.05). The highest weight gain was recorded in Diet 1 (8847.73±292.65 g) > Diet 2 (7816.33±121.71 g)>Diet 3 (7811.67±566.08 g) >Diet 4 (7022.00±44.193 g). Similarly, the best feed conversion ratio was found in fish fed Diet A (10.12±0.01),>Diet B, C and D had the same values of 0.11 g respectively. There was no significant (p>0.05) difference in plasma biochemical indicators measured when compared to the control (Diet A). Thus, indicating that all the fish were healthy and had normal physiological activities. Cockroach meal can therefore, be used as a feed supplement without having any adverse effect on the growth and well-being of hybrid catfish fingerling

Bacteria and fungi analyses of fish diets with grasshopper and cockroach meals: the potential replacement of fishmeal in fish diets

The need to further ascertain the quality of fishmeal with biological indicators has poised this study to determine the biological characterisation of formulated diets with supplemented insect protein (variegated grasshopper and American cockroach). The diets (A–F) were prepared with local ingredients (A, 100% grasshopper meal; B, 100% fishmeal; C, 1:1 grasshopper:fishmeal; D, 1:1 cockroach:fishmeal; E, 100% cockroach meal; F, commercial diet). Samples of prepared diets ready to be stored for use were subjected to bacteria and fungi test. Diet F recorded the highest (4.60±1.10×102 cfu g–1) total viable bacteria count. The highest (3.00±0.05×102 cfu g–1) fungi count was recorded in diet A. Six probiotics bacteria were isolated from the diets. Lactobacillus delbrueckii subsp. bulgaricus was only isolated in grasshopper containing diets; as Pediococcus pentosaceus, Bifidobacterium longum, Mycobacterium marinum, Bacillus subtilisand, Lactococcocus lactis were only isolated in diets F, E, D, A and B respectively. Two pathogenic bacteria isolated were Streptoccoci pyogenes and Staphylococcus aureus. Aspergillus flavus and Penicillum sp. are the two species of fungi isolated from diet A, and diets C and E respectively. The diets with insect proteins were rich in probiotic bacteria than other diets may be considered to replace fishmeal in fish diet

Human rhinosporidiosis of the nasal cavity: a case report.

Rhinosporidiosis is a rare chronic granulomatous disease caused by Rhinosporidium seeberi. It is endemic in some parts of Asia and commonly involves the mucous membrane of the nose presenting with nasal obstruction, a nasal mass, and epistaxis. The main treatment for rhinosporidiosis remains surgical excision, although it may recur after excision. Rhinosporidiosis is a condition that clinicians should keep in mind when managing patients with nasal masses even in non-endemic areas. Case presentation: A 52-year-old housewife presented with a 9-month history of left progressive nasal obstruction and progressive enlarging left nasal growth associated with recurrent nasal bleeding and nasal discharge. She had a history of rearing animals and bathing in ponds as well as engaging in farming activities. Examination revealed a fleshy polypoid mass attached to the nasal septum by pedicle and filling the whole of the left nasal cavity covered with a mucopurulent nasal discharge with associated contact bleeding. She had endoscopic resection under local anaesthesia with cauterization of the base of the mass with a silver nitrate pencil. A histopathological diagnosis of rhinosporidiosis was made. Conclusion: Rhinosporidiosis is rare in our environment, its presentation mimics that of nasal tumours. Therefore, it should be part of the differential diagnosis; both clinicians and pathologists should have it at the back of their minds when managing patients with nasal masses even in non-endemic areas

Characteristics of Different Type of Coarse Aggregate on Properties of High Performance Concrete

The weakest links of conventional cement concrete is often occurred at the transition zone around coarse aggregate particles and the bulk of the compressive load is also borne by the cement paste. However, in special concrete such as High Strength Concrete (HSC) and High Performance Concrete (HPC) where, the water/cement ratio is low and high content of cement constitute their characteristics, the bulk compressive load is borne by the aggregate. Therefore, the failure in such concrete is mostly through the aggregate. This study discussed the characteristics of different type of coarse aggregate with distinct size range, 20-14mm and 10-5mm on properties of high performance concrete. In this project, investigation such as Slump test and Unit weight were carried out on fresh properties, and also compressive strength and water absorption on hardened properties, in which, readings were taken at curing days of 7 days, 14 days, and 28 days. The water to cement ratio used is 0.35, 1% super plasticizer of  Conplast SP-430 were added, and the dosage of meta kaolin added was  0%, 7.5% and 15%. The HPC mix, grade M40concrete is designed as per ACI method. The result of the study indicated that the compressive strength increases with an increase in percentage of Metakaolin between 0% to 15% replacements. Basalt-mixed concrete gives higher compressive strength, followed by gneiss-mixed concrete, then granite-mixed concrete. It was also discovered that larger aggregate sizes (20mm-14mm) gives high compressive strength than smaller sizes (5mm-10mm). Therefore for optimum performance up to 15% replacement of Metakaolin can be used with 20mm-14mm sizes of basalt aggregate

In situ remediation of lead contaminated marine sediment using bentonite, kaolin and sand as capping materials

There is a growing public concern over the issue of sediment contamination resulting from industrial and municipal waste discharge, mining activities, and improper use of chemical fertilizer, pesticides, and wastewater irrigation. However, there is a need to reduce the continuous contamination of the water column and biota by the pollutants in the sediment. The conventional approach of contaminated sediment treatment is dredging but is expensive and requires a large area of land for disposal. In situ capping of contaminated sediment is considered as a cheaper technique compared to dredging and efficient treatment technology to immobilize pollutants in sediments on site. A laboratory-scale capping experiment was conducted to evaluate the effectiveness of using bentonite (B), kaolin (K), a mixture of bentonite with kaolin (BK), and sand in immobilizing lead-contaminated sediment using in situ capping treatment technology. The results indicated that applying bentonite, kaolin, and sand as capping materials has the potential to effectively reduce the release of lead from the heavily spiked contaminated marine sediment (3000 ppm) to the overlying water. The adsorption kinetics results obtained showed that the experimental data for adsorption of Pb fitted well to the Elovich, Second-order and Twoconstant rate kinetic models as judged by highest values of R2 and the lowest values of standard error of estimate (SE) such as R2 of 0.937, 0.735, 0.932 with SE values of 0.23, 2.62 and 0.26 for B, K and BK respectively in the Elovich, likewise R2 of 0.817, 0.935, 0.821 with SE values 0.33, 0.07 and 0.19 for B, K and BK in the Second-order and R2 of 0.938, 0.637, 0.925 with SE values of 0.000135, 0.0015 and 0.00024 for B, K and BK were obtained for Two-constant rate models, which implied that the process of adsorption was by chemisorption

Prevalence of bacteria isolates in water and some biota of Lapai-Agaie Dam, Nigeria

Lapai-Agaie dam play a pivotal role as primary source of domestic water supply, agricultural (irrigation and fisheries) activities to the host communities. Therefore, this study assessed the prevalence of bacterial isolates in water and on some biota (macrophytes and fishes) in order to provide basic information on bacterial diversity of the dam. The water pH and temperature of the identified sample sites were determined. Water sample for bacteria isolation was collected across water surface at each sites into 500ml sterile container. Macrophytes from the sampling sites were wholly collected with forceps into a sterilized plastic container; while fish samples were obtained from the landing site and placed in sterilized polythene bag for subsequent analyses. The standard procedures for bacteria sampling and identification were employed using phenotypic identification techniques. Water pH was significantly different (p<0.05) between sampling sites. Six bacteria isolates were identified from the two water sampling sites. Site A recorded the highest average bacterial colony count of 0.96x22x108 cfu/ml with Escherichia coli (12(29 %)) as the most frequent isolate. A total number of seventeen (17) genera of fishes where eleven bacteria were isolated. The fish coded FS3 recorded the highest distribution bacteria isolates. Three species of macrophytes were identified in the dam, with the highest bacteria population of 1.85±0.24x107cfu/ml in the stem of Leerisia havedra as it had the highest bacterial population of 16.42±0.43x107 cfu/ml. Twelve (12) bacteria isolates where identified from the macrophytes with Klebsiella pneumonia recording the highest frequency of 8(16 %). However, the distribution of pathogenic bacteria in water was lower than that on the fishes and macrophytes. An indication that the biota may act as causative agent of epidemic disease. Therefore, the existence of these isolates pose challenges to human health, if proper hygiene and implementation of aquatic water policy and regulations are not properly enforced to discourage anthropogenic pollution.Keywords: Lentic, Biodiversity, Fish, Macrophytes, Bacteri

Combined treatment of domestic and pulp and paper industry wastewater in a rice straw embedded activated sludge bioreactor to achieve sustainable development goals

The pulp and paper industry has been recognized as one of the largest users of water worldwide. Water is used in nearly every step of the manufacturing process. It generates significant amounts of wastewater and leftover sludge, creating several problems for wastewater treatment, discharge, and sludge disposal. Adopting the most effective and economical treatment techniques before discharging wastewater is therefore crucial. Thus, this study aims to evaluate the performance of the activated sludge bioreactor system (ASBS) for the treatment of pulp and paper industry wastewater (PPIW). The PPIW was characterized. During the experiment, the domestic and PPIW wastewater were run at a fixed HRT of 1 day. Subsequently, the ASBS was evaluated by varying the HRT and OLR. The HRT was varied in the range of 3, 2, and 1 day. At a fixed HRT of 2 days, the maximum and minimum COD removal were 88.4 and 63.2%. Throughout the study, the ASBS demonstrated higher treatment efficiency in terms of COD removal. First order, Grau second order, and modified Stover Kincannon biokinetic models were applied for the study. The biokinetic investigation shows that the modified stover kinetic model was more appropriate for the description of the experimental data in terms of microbial growth parameters. Thus, the kinetic coefficients obtained in this study could be used for the bioreactor scale-up. The study has also proven that the biosorbent made from biomass waste can potentially help preserve non-renewable resources and promote zero-waste attainment and principles of a circular bioeconomy

Perception and beliefs about mental illness among adults in Karfi village, northern Nigeria

BACKGROUND: This study was designed to examine the knowledge, attitude and beliefs about causes, manifestations and treatment of mental illness among adults in a rural community in northern Nigeria. METHODS: A cross sectional study design was used. A pre-tested, semi-structured questionnaire was administered to 250 adults residing in Karfi village, northern Nigeria. RESULTS: The most common symptoms proffered by respondents as manifestations of mental illness included aggression/destructiveness (22.0%), loquaciousness (21.2%), eccentric behavior (16.1%) and wandering (13.3%). Drug misuse including alcohol, cannabis, and other street drugs was identified in 34.3% of the responses as a major cause of mental illness, followed by divine wrath/ God's will (19%), and magic/spirit possession (18.0%). About 46% of respondents preferred orthodox medical care for the mentally sick while 34% were more inclined to spiritual healing. Almost half of the respondents harbored negative feelings towards the mentally ill. Literate respondents were seven times more likely to exhibit positive feelings towards the mentally ill as compared to non-literate subjects (OR = 7.6, 95% confidence interval = 3.8–15.1). CONCLUSIONS: Our study demonstrates the need for community educational programs in Nigeria aimed at demystifying mental illness. A better understanding of mental disorders among the public would allay fear and mistrust about mentally ill persons in the community as well as lessen stigmatization towards such persons