Parasitological Profile of Raw Wastewater and the Efficacy of Biosand Filter in Reduction of Parasite Ova and Cysts

The disposal of wastewater in water bodies has a negative impact in theenvironment and the health of people who use such water bodies for either irrigation or drinking purposes. In this study, we evaluated the  parasitological profile of wastewater from the Ahmadu Bello University Teaching Hospital sewage treatment plant, Zaria, Nigeria using the magnesium sulphate floatation method. The parasite removal efficiencyof biosand filter was also tested in comparison with the sewage treatment plant. A total of 960 L of wastewater was examined and a significant level of parasite eggs, cysts and oocysts were detected. In all, 1,648 parasites eggs, cysts and oocysts per litre were counted. Ova of Ascaris spp showed the highest count/litre of 307 (18.63%) followed by ova of Taenia spp (n=287; 17.42%). The least count per litre was exhibited by cysts of Giardia spp (n=58; 3.52%). The analysis revealed that 52.61% of the parasite eggs, cysts and oocysts was removed by the sewage treatment plant while egg removal efficiency of the biosand filter was 97.45%. Further comparison of mean parasite eggs/litre in the effluents of biosand filter and the sewage treatment plant using Wilcoxon’s Signed Ranks Test indicated a significant difference (p < 0.05) with biosand filter having lower  counts per litre. The results obtained therefore demonstrate that the raw wastewater was laden with parasite eggs, cysts and oocysts and hence pose public health threat to the users of the effluent downstream. The biosand filter was more efficient than the sewage treatment plant; its effluent contains insufficient level of the ova, cysts and oocysts of parasites well below the less than one (<1) helminth ova/protozoa cysts as  recommended by WHO

Resistance to some Heavy Metals among Fungal Flora of Raw Refinery Effluent

Investigations were carried out to assess the capacity of strains of fungi isolated from raw flowing effluent and effluent retention pond of Kaduna refinery plant to resist and grow in the presence of lead (Pb), nickel (Ni) and cadmium (Cd) invitro. Fungi belonging to the genera including Aspergillus spp., Penicillium spp., Fusarium spp., Curvularia spp. and Nigrospora spp. were isolated from the study sites. The isolates were inoculated into duplicate 100ml flask containing 50ml of potato dextrose broth (PDB) supplemented with 5,10 and 15ppm of Pb, Ni, and Cd. Each test isolate was inoculated into duplicate flask containing the same medium without the heavy metals to serve as control. All inoculated flasks were incubated aerobically at room temperature on a rotator shaker for 7days. The mycelial mats were harvested by filtering the cultures through preweighed filter paper (No.1). The filters bearing the mycelial mats were dried in an oven at 70oC for 18hours. It was observed that most of the isolates tested resisted and grew in the medium containing 5 to 15ppm of tested heavy metals. Yield of dry mycelia mats in the heavy metal supplemented medium were also comparable to those grown in heavy metal free PDB medium. It was concluded that, these genera of fungi could be playing an important role in the removal of these metals usually present in the raw effluent during the period of residency in the retention pond through bioaccumulation. ©JASEMKeywords: Fungal flora, Heavy metals, Resistance, Refinery effluent

Composition of Fungal Flora in Raw Refinery Effluent, Effluent Retention Pond and a Treated Effluent Recipient River

Investigations were carried out to determine the composition of fungal flora in the studied sites. Samples of the raw effluent were collected along the flow channel and the retention pond. Water samples were also collected at the discharge point and up and down stream of the river from the discharge point. The samples were spinned at a speed of 250rpm for 10minutes and spread inoculated the deposits on potato carrot agar (PCA) and potato agar supplemented with 7.5% Nacl. Inoculated plates were incubated aerobically at room temperature in dark cupboard for 7days. Fungal colonies that emerged on the primary culture plates were distinguished into types. The pure isolates were characterized into genera using standard taxonomic guides. Genera such as Aspergillus, Penicillium, Curvularia, Fusarium, Microsporum, Trichoderma, Rhizoctonia, Nigrospora and Chaetophoma species were detected in the raw effluent. However, Microsporum, Trichoderma, Rhizoctonia, Nigrospora and Chaetophoma species were conspicuously absent in the effluent retention pond. Only Trichoderma and Chaetophoma species were absent in water samples collected at the treated effluent discharge point into the recipient River. Samples of water collected up stream of the discharge point did not contain Geotrichum, Nigrospora and Chaetophoma species. Curvularia, Microsporum, Rhizoctonia and Nigrospora species were not detected in water samples collected downstream of the discharge point. It was therefore concluded that, fungi constitute a significant proportion of the microflora of sites contaminated with the refinery effluent and could be playing an important role in the remediation of sites receiving the effluent. © JASEMKeywords: Fungal flora, Refinery effluent, Retention ponds, Discharge point, Upstream, Downstrea

Modification of Bacillus cereus and Pseudomonas aeruginosa isolated from a petroleum refining effluent for increased petroleum product degradation

Bacillus cereus and Pseudomonas aeruginosa isolated from Kaduna refining and petrochemical company (KRPC) were subjected to ultra-violet (UV)-irradiation for 30 min followed by nitrous acid treatment and re-irradiated with UV light for 30 min using standard methods and their petroleum degradation abilities were compared with parent strains. Prior to modification, B. cereus and P.aeruginosa grew on minimal basal medium containing 1.5 and 1% crude oil, respectively, initially but on re-inoculation, both organisms grew on minimal basal medium containing 5% crude oil. 99.83 (0.17% survival) and 96.91% (3.08% survival) death were recorded on UV-irradiation for 30 min; 38.24 (61.76% survival) and 82.02% (10.98% survival) death were recorded after nitrous acid treatment and 29.01 (70.99% survival) and 95.76% (4.24% survival) death were observed on re-irradiation with UV light for 30 min for B. cereus and P. aeruginosa, respectively. Petroleum product degradation increased from98.92% for parent B. cereus to 99.70% for UV-irradiated nitrous acid treated B. cereus, and from 91.34% for parent P. aeruginosa to 98.09% for UV-irradiated nitrous acid treated P. aeruginosa. However, itdecreased from 98.92 to 97.87% and increased from 91.34 to 97.87% for parents and second stage mutants re-irradiated with UV light of B. cereus and P. aeruginosa, respectively. Higher potential were observed for second stage mutant of B. cereus than P. aeruginosa. Thus, the modification of the organisms with UV-irradiation for 30 min followed by nitrous acid treatment resulted in their increased petroleum product degradation ability and could therefore be used for bioremediation of environmentspolluted with petroleum products of 1 - 5% (v/v)

Multidrug Resistance Patterns and Multiple Antibiotic Resistance Index of Salmonella species Isolated from Waste Dumps in Zaria Metropolis, Nigeria

Several items containing residual antimicrobial agents are disposed of in dumpsites, placing a pressure on the microbial flora and a potential for development of resistance in these microorganisms. Multidrug resistancepatterns and multiple antibiotic resistance index of Salmonella spp. isolated from waste dumps in Zaria Metropolis were thus assayed in this study using one hundred and twelve (112) soil samples collected from four waste  dumpsites located in Sabon-Gari, Samaru, Tudun-Wada and Zaria City. Salmonella spp. were isolated by culture methods on selective media and characterized using a series of biochemical tests. The isolates were confirmed using microgen identification kits. Results were statistically analysed using percentages. The antibiotic resistance patterns were determined, using the disc-diffusion method. Ten antibiotics belonging to eight different classes, namely B-lactams, aminoglycosides, tetracycline, cephalosporins, fluoroquinolone, Nitrofurantoins, sulphonamides, and phenicols were tested. The result of the study revealed that 57.2% of the isolates exhibited multidrug resistance (MDR) taken as resistance to four or more antibiotics tested. On the other hand, all the isolates showed 100% susceptibility to Chloramphenicol (30μg) and Gentamicin (30μg) while 76.2% had Multiple Antibiotic Resistance (MAR) Index of 0.2 and above. The isolates showing resistance to the highest number of antibiotics were obtained from refuse dumpsites in Zaria City while an isolate from Sabon-Gari was found to be resistant to six antibiotics. These results could be indicative of possible disposal of these drug residues in the waste dump locations making them hot spots for development of resistance.Keywords: Salmonella spp., Waste Dumps, Resistance Pattern, MAR Index, Zaria Metropolis

Parasitological Profile of Raw Wastewater and the Efficacy of Biosand Filter in Reduction of Parasite Ova and Cysts

The disposal of wastewater in water bodies has a negative impact in the environment and the health of people who use such water bodies for either irrigation or drinking purposes. In this study, we evaluated the parasitological profile of wastewater from the Ahmadu Bello University Teaching Hospital sewage treatment plant, Zaria, Nigeria using the magnesium sulphate floatation method. The parasite removal efficiency of biosand filter was also tested in comparison with the sewage treatment plant. A total of 960 L of wastewater was examined and a significant level of parasite eggs, cysts and oocysts were detected. In all, 1,648 parasites eggs, cysts and oocysts per litre were counted. Ova of Ascaris spp showed the highest count/litre of 307 (18.63%) followed by ova of Taenia spp (n=287; 17.42%). The least count per litre was exhibited by cysts of Giardia spp (n=58; 3.52%). The analysis revealed that 52.61% of the parasite eggs, cysts and oocysts was removed by the sewage treatment plant while egg removal efficiency of the biosand filter was 97.45%. Further comparison of mean parasite eggs/litre in the effluents of biosand filter and the sewage treatment plant using Wilcoxon\u2019s Signed Ranks Test indicated a significant difference (p < 0.05) with biosand filter having lower counts per litre. The results obtained therefore demonstrate that the raw wastewater was laden with parasite eggs, cysts and oocysts and hence pose public health threat to the users of the effluent downstream. The biosand filter was more efficient than the sewage treatment plant; its effluent contains insufficient level of the ova, cysts and oocysts of parasites well below the less than one (<1) helminth ova/protozoa cysts as recommended by WHO

Prevalence of Escherichia coli some public water sources in Gusau Municipal, North Western Nigeria

This study investigated the presence of Escherichia coli from some public water sources in Gusau municipal, north- western Nigeria. This was done by determining the total coliform counts and the presence of Escherichia coli and its antibiotic susceptibility profile. A total of 180 well 60 tap and 60 packaged water samples were obtained from Gusau municipal on weekly basis over a period of seven month (August, 2006-Feb, 2007) covering part of rainy and dry seasons. Standard procedures were used for the identification of Escherichia coli and for estimating total coliform counts. All samples had coliform counts higher than the international standard recommended by the World Health Organization. Results of biochemical analysis of the samples showed that out of 63 confirmed Escherichia coli isolated, 41 (45.5%) were from well water, tap water had 14 (23.3%) while packaged water had 8(13.3%).The susceptibility profile of the isolates to nine antimicrobial agents indicated that majority of the isolates were highly susceptible to Chloramphenicol, Gentamycin, Perrfloxacin, Tarivid, Augmentin, Streptomycin, Sparfloxacin, and Ciprofloxacin, moderate susceptibility to Septrin and resistant to Amoxacilin were observed. None of the water samples met the WHO standards for drinking water and thus pose a serious health risk to its consumers and users if not properly treated. Key words: Bacteriological quality, Escherichia coli, Prevalence, susceptibility profile, public water sources, Gusau