Analysis of the Correlation among Three Oxygen Demand Indexes in Surface Water

Based on the monitoring data of chemical oxygen demand(COD),permanganate index(I Mn)and five-day biochemical oxygen demand(BOD 5)of surface water in Tongling section of Yangtze River,the linear relationship among the three indexes in the annual data analysis and the internal reasons,as well as the linear relationship and changes among the three indexes in different seasons were analyzed.The results reveal that in terms of the whole year,COD,I Mn and BOD 5 had a significant correlation and good linear relationship.The fitting slopes of the three indexes were 3.89 of COD/I Mn,4.39 of COD/BOD 5 and 1.16 of I Mn/BOD 5,respectively,which corresponded to the proportional relationship among the three indexes.From the perspective of seasonal changes,there was a very significant correlation between the three indexes in spring and summer.In autumn and winter,only COD and I Mn had a good correlation,but they had a poor correlation with BOD 5.

Variations in oxygen and some related pollution parameters in some streams in ITU Area of Nigeria

The analyses of water from four tributaries of Ikpa River: Afaha Nsai Stream (ANS), Ikot Ekpuk Stream (IES), Afaha Itam Stream(AIS) and Nduetong Stream (NDS) in International Telecommunication Union (ITU) Local Government Area of Akawa Ibom State in Nigeria were carried out using standard analytical procedures. The parameters investigated were temperature(Temp.), hydrogen ion concentration(pH), total suspended solids (TSS), total dissolved solids (TDS), dissolved oxygen (DO) and biochemical oxygen demand (BOD). Correlation analysis carried out between pairs of variables showed that only the correlation coefficients between TDS and DO in ANS( p <0.05); Temp. and TDS in IES ( p <0.05) and between Temp. and TDS in AIS ( p <0.01) were significant. None of the pairs of the variables in NDS showed any significant correlation. The coefficients of variation for the parameters were also computed and used in determining their stability in the water. The possible effects of these variables on each other and on the aquatic ecosystem were discussed.

Disruption of biofilms from sewage pipes under physical and chemical conditioning

Biofilms grown inside two sewage collecting pipes located in industrial and residential areas are studied. Bacterial biomass inside three layers of biofilms was evaluated. Biofilm cohesion under different mixing rate and ionic strength was also investigated. Effects of physical and chemical parameters in the biofilms were evaluated by monitoring turbidity, chemical and biochemical oxygen demands. Extracted organic matter from biofilms was partitioned to polar, aromatic and saturated fractions using activated silica column chromatography. Results revealed that bacterial biomass growth depending on biofilm thickness and stratification. The most loaded stratum in bacteria/biomass was the sewage-biofilm interface stratum that represented 51% of the total bacteria/biomass. Stirring rate and ionic strength of mono- and bivalent salts showed a major influence in biofilm disruption. The stirring time enhanced the exchange dynamic and matter capture between biofilm fragments at the critical stirring rate 90 r/min. Sodium chloride showed the dispersing effect on biofilms in suspension, and decreased the BOD5 （biochemical oxygen demand） beyond the physiological salt concentration.

Characterisation of Raw Sewage and Performance Evaluation of Al-Diwaniyah Sewage Treatment Work, Iraq

These days, water and wastewater treatment are one of the most important issues regarding to the human health. Wastewaters are one of the most environmental pollutants and a wide range of adverse effects linked to the effect of untreated wastewaters or wastewaters that treat improperly. The aim of this present study was to evaluate performance of the wastewater treatment plant at Al-Diwaniyah City according to the national standards. Therefore, data of the most common parameters (PH, BOD5, COD, TSS, PO4, NO3, Cl, and Oil and Grease) were collected from the wastewater treatment plant. The study revealed that the wastewater treatment plant was receiving medium to strong influent with a BOD5/COD ratio of between (0.4 - 0.7). Regression analysis was achieved to approximate the influent of BOD5 and TSS. While the effluent quality was exceeded the Iraq standards for disposing treated wastewater to the water bodies with a fluctuation in the ratio of BOD5to COD as a consequence of the operational problems. Therefore, these results would be of help to planners and policy makers in the City to combat such this problem and to take the necessary actions to reduce the impact of these pollutants.

Performance of Common Reed(Phragmites australis)in a Constructed Wetland for Greywater Treatment in Akure,Nigeria

Shortage of freshwater is becoming a growing problem in both dry and semi-dry regions of the world,hence the need to make use of other source of water for agricultural production.The study was conducted to examine the performance of common reed in a constructed wetland for greywater treatment in Akure,Nigeria.Raw greywater was collected from Jadesola Hostel,Federal University of Technology,Akure,and pretreated through a combination of gravel of diameters<32 mm,24 mm and 16 mm with fine sand of diameter 0.2 mm arranged accordingly.The filtered water was thereafter released to a plastic constructed wetland(CW)which also consisted of same combination of layers of gravel and sand with common reed planted on it for complete treatment.The raw and treated greywater were analyzed for Biochemical Oxygen Demand(BOD),Chemical Oxygen Demand(COD),Total Dissolved Solid(TDS),and heavy metals.It was discovered that CW planted with common reed was effective in the treatment of greywater with reduction in BOD by 91.4%,COD by 91.5%and TDS by 38.7%.CW had appreciable removal effect on heavy metals with reduction in:manganese(Mn)from 0.100 ppm to 0.012 ppm,iron(Fe)from 0.014 ppm to 0.002 ppm,lead(Pb)from 0.05 ppm to 0.001 ppm and zinc(Zn)from 0.154 ppm to 0.148 ppm.Therefore,the use of common reed in constructed wetland for greywater treatment is recommended for farmers involved in irrigation with greywater,especially during dry seasons,and most importantly under the rising global water scarcity due to climate change.

Differential fate of metabolism of a disperse dye by microorganisms Galactomyces geotrichum and Brevibacillus laterosporus and their consortium GG-BL

The present work aims to evaluate Brown 3 REL degrading potential of developed microbial consortium GG-BL using two microbial cultures, Galactomyces geotrichum MTCC 1360 （GG） and BrevibaciUus laterosporus MTCC 2298 （BL）. Microbial consortium GG-BL showed 100% decolorization of a dye Brown 3 REL, while individually G. geotrichum MTCC 1360 and B. laterosporus MTCC 2298 showed 26% and 86% decolorization under aerobic condition （shaking） respectively. Measurements of biochemical oxygen demand （BOD） （76%） and chemical oxygen demand （COD） （68%） were done after decolorization by consortium GG-BL. No induction in activities of oxidoreductive enzymes found in G. geotrichum while B. laterosporus showed induction of veratryl alcohol oxidase, Nicotineamide adenine dinucleotide-dichlorophenol indophenol （NADH-DCIP） reductase and riboflavin reductase indicating their role in dye metabolism. Consortium GG-BL showed induction in the activities of laccase, veratryl alcohol oxidase, tyrosinase, NADH-DCIP reductase and riboflavin reductase. Two different sets of induced enzymes from G. geotrichum and B. laterosporus work together in consortium GG-BL resulting in faster degradation of dye. The degradation of Brown 3 REL was analyzed using high performance thin layer chromatography （HPTLC）, high performance liquid chromatography （HPLC）, Fourier transform infrared spectroscopy （FT-IR） and gas chromatography mass spectroscopy （GC-MS）. Phytotoxicity study revealed that metabolites formed after degradation was significantly less toxic in nature.