Wastewater is untreated water that has high amount of nutrients such as nitrate, phosphate, ammonium and chemical oxygen demand (COD). When it is discharged into watercourse, it affects human and aquatic biota. The application of photosynthetic bacteria is considered bio-friendly system than the conventional one. Hence, the present study investigates the effectiveness of robust strain of photosynthetic bacteria for nitrate removal under different concentrations of 85, 135, 190, 235 and 320 mg/L. Serial dilution techniques was used for the isolation of the bacteria. The results showed that three bacterial isolate were obtained and were both screened for nitrate reduction ability. The isolate was able to remove 91, 90, 71, 67 and 55% of nitrate at 85, 135, 190, 235 and 320 mg/L respectively. The bacteriochlorophyll of the isolate was detected at peak range between 689-710 nm. The morphological, physiological and biochemical characterization showed that the isolate was identified as Rhodopseudomonas sp. The nutrient removal yield of the nitrate under different concentrations was found to be at range of 0.01- 0.033 g-1 DCW g-1 NO3.- This study suggested that the strain could be used as an efficient bacterial candidate for the treatment of wastewater containing high amount of nitrate.

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Heavy metal contamination often occurs when there is an abnormal discharge of metal in the environment. This is caused mainly by human activities such as agriculture, mining and industrialization. When this heavy metal gets into the environment, it adversely affects plants, humans and aquatic biodiversity. Conventional treatment methods have been applied extensively, hence these methods are inefficient and expensive to carry out. This study was conducted to assess whether castor plants could be able to absorb heavy metal actively from the soil. Metal ions determined are lead and copper at different concentrations of 1.5, 2 and 2.5 g/dm3. The soil located at Gombe State University Botanical Garden was used for the cultivation of the plant. Acid digestion and Atomic Absorption Spectroscopy were used for metal determination. The results of the study showed that Copper and Lead were absorbed the highest in the leaves than in stem and root by the absorption efficiency of 100, 91 and 87% respectively. The plant leaves and roots accumulate high Lead content of 2.661, 2.43, in the root, 1.26, 1.52, and 0.031, 0.3 in the stem for both lead and copper respectively. Results of translocation factor revealed the highest absorption of metal from Root to stem of 1.83, 1.98, and the least was 0.36, 0.34, for copper and lead respectively.