Wastewater treatment plants as a source of microbial pathogens in receiving watersheds

Wastewater treatment facilities have become sin quo non in ensuring the discharges of high quality wastewater effluents into receiving water bodies and consequence, a healthier environment. Due to massive worldwide increases in human population, water has been predicted to become one of the scarcest resources in the 21st century, and despite large advances in water and wastewater treatments, waterborne diseases still pose a major threat to public health worldwide. Several questions have been raised on the capacity of current wastewater treatment regimes to remove pathogens from wastewaterwith many waterborne diseases linked to supposedly treated water supplies. One of the major gaps in the knowledge of pathogenic microorganisms in wastewater is the lack of a thorough understanding ofthe survival and persistence of the different microbial types in different conditions and environments. This therefore brings to the fore the need for a thorough research into the movement and behavior of these microorganisms in wastewaters. In this review paper we give an overview of wastewater treatment practices with particular emphasis on the removal of microbial pathogens

In vitro assessment of antioxidant, phytochemical and nutritional properties of extracts from the leaves of Ocimum Gratissimum (linn).

The antioxidant, phytochemical and nutritional properties of acetone, methanol and aqueous extracts of the leaves of Ocimum gratissimum (Linn) were investigated to evaluate the therapeutic and nutritional potential of the leaves of this plant. The antioxidant of the plant extracts were assessed against 1,1-Diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azinobis-(3- ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and ferric reducing agent. Total phenolics, flavonoids, flavonols and proanthocyanidins were determined to assess their corresponding effect on the antioxidant activity of this plant. The extracts exhibited DPPH and ABTS.+ radical scavenging activities, which was comparable to butylated hydroxytoluene (BHT). The phytochemical screening revealed the presence of alkaloids, tannins, saponin, steroids, cardiacglycoside, flavonoid, terpenoids and phenol. The proximate analysis confirms that the leaves contain appreciable amount of ash, crude protein, lipids, fibre and carbohydrates. The macro and micro elements and constituents revealed that the leaves contain significant amount of sodium, potassium, calcium, magnesium, iron, zinc, phosphorus, copper, nitrogen, and manganese. This study shows that the leaf can be used as a therapeutic agent and justifies its application in folkloric medicine.Keywords: Ocimum gratissimum, oxidative stress, polyphenolic, proximate composition, therapeutic activit

Assessment of physicochemical qualities, heavy metal concentrations and bacterial pathogens in Shanomi Creek in the Niger Delta, Nigeria

The physicochemical and microbial qualities of Shanomi creeks in the Niger Delta of Nigeria were assessed between January and October 2011. The temperature across sampling stations ranged between 26 and 27.7‹C, while pH varied from 7.49 to 8.74. Turbidity ranged from 176.62-189.96 NTU and conductivity varied between 360.45 and 454.88 ƒÊS/cm. The concentrations of other physicochemical parameters were as follows: BOD (6.39-7.64 mg/L) COD (84.25-97.27 mg/L); ammonia (26.83-33.98 mg/L); nitrate (37.25-43.89 mg/L); nitrite (37.35-41.75 mg/L); and phosphate (28.83-37.85 mg/L). The relative dominance of metals in the water followed the sequence: Al > Zn > Cu > Fe > Mn > Cd > Pb > Hg > As. Feacal and total coliform densities ranged from 1.05 ~ 102 to 4.25 ~ 103 (cfu/mL) and 1.56 ~ 102 to 6.40 ~ 104 (cfu/mL) respectively. The study reveals that the water under study was heavily polluted and of serious threat to the aquatic biota and public health.Key words: Aquatic biota, contamination, pollution, public health, microbial indicators, toxic effects

Control strategies to combat dissemination of antibiotic resistance in urban water systems

The intensive use of antibiotics for medical, veterinary, or agricultural purposes results in the continuous release of antibiotics into the environment, leading to the increasingly widespread occurrence of antibiotic resistance. Although antibiotic resistance has been recognized as a major threat to human health worldwide, the related phenomenon occurring in natural and engineered environments has so far been largely overlooked. The urban (including industrial) water cycle, which connects urban life, agriculture, and the environment, is potentially a hot spot for the spread of antibiotic resistance. Therefore, better understanding of the distribution and transportation of antibiotic-resistant bacteria (ARB) and acquisition of antibiotic resistance genes (ARGs) in the urban water cycle is critically important to improve the control of this emerging environmental and human health challenge. In this book chapter, we comprehensively review the occurrence, transfer, and acquisition mechanisms of ARGs in the urban water cycle. Various methods that are used to monitor ARB and ARGs are compared in terms of their strengths and limitations. Opportunities for the development of real-time monitoring methods are discussed, along with possible control strategies for ARB and ARGs in urban water environments. We recommend that three major barriers should be developed to minimize or halt the spread of ARGs in urban water systems, including more efficient water disinfection, advanced wastewater treatment, and optimized sludge treatment processes