International Journal Of Environmental Research
Volume:2 Issue: 4, Autumn 2008

A lab-scale expanded granular sludge bed (EGSB) reactor was operated at 20°C with low strength wastewater (0.6-0.8 g COD/L) for over 200 days. Reactor was inoculated with mesophilic granular sludge. The up-flow velocity was set to 5 m/h by effluent recirculation. The COD loading was increased up to 12 kg COD/m3/day until the day 76, resulting in hydraulic retention time of 1.5 hours. Physical properties (settleability and diameter) of retained sludge tended to deteriorate during the first 2-3 months, however sludge settleability kept sufficiently in the later part of experiment due to the reconstruction of granular sludge. The growth yield (Yg) of retained sludge (0.13 g VSS/g COD) was about two times higher than mesophilic and thermophilic granular sludge processes while the endogenous decay constant (Kd) is very low (0.0001/day) as compared with those processes. The sludge retention time of retained sludge reduced from 100 days to 40 days by the reduction of hydraulic retention time from 4 hours to 1.5 hours. Maintenance of 40 days of sludge retention time caused the stable retainment of biomass and the significant increase of methanogenic activity of the retained sludge.

Sediments from the surface, core waterwaand vegetation of tropical mangroves were collected from tropical mangroves, India. Total phosphorus, total nitrogen, organic carbon, protein, carbohydrate and tannin and lignin in these samples were estimated. The C/N and C/P of the leaves present in Mangalavanam, Vypeen, and Nettoor are in good agreement with that of the sediment and this -result indicated that the main source of the sediment organic matter is the plant remains. The profile of C/N ratios shows a decrease towards the depth, but lies within that of the oligotrophic lakes and plant tissues and peat. The decay rate of C and N indicated that the main reactivity is in the first 5cm of the sediment, which is subjected to re-suspension and significant bio-turbation. But there existed a uniform decay pattern at 10 cm and 15 cm. In the case of monsoon season and post monsoon season a random character was observed at 15 cm depth, which can be attributed to the effective release of organic matter from that depth zone. To assess the reactivity of the systems, the classic one G model with slight modifications to suit to the system was employed.

Heavy metals in the aquatic environment have to date originated fundamentally from naturally occurring geochemical resources. Nonetheless, this has been enhanced by anthropogenic activities resulting in pollution. Consequently, relationships and partitioning of heavy metals in the dissolved phase, suspended particulate matter (SPM), sediments and shrimp (Macrobrachium felicinum) were investigated in five selected sites along Taylor creek, southern Nigeria. The degree of relationships between the various metals was dissimilar in each of the investigated matrices. In the matrices studied, not several significant relationships (P<0.05) were obtained. Only Ni-Cd (r=0.95), Mn-Cd (r=0.63), Mn-Ni (r=0.64) were associated in the sediments and in SPM, Zn-Ni (r=0.72), which suggests that the sources were not common for both matrices. In the dissolved phase, no strong relationships (P<0.05) between the heavy metals were obvious. The best relationships were observed for Ni-Zn (r=0.72) and Cd-Pb (r=0.65). Partitioning coefficients (Kd) of heavy metals between dissolved phase and SPM were generally low, which is typical for fresh water ecosystems and fairly stable over the creek all through the seasons. Furthermore, the bio-concentration factors (BCFs) of Macrobrachium felicinum were low unlike those of other natural waters. Thus, the physical state of the aquatic ecosystem points to the fact that the heavy metals bio-accumulated by Macrobrachium felicinum give cause for concern when viewed in perspective to community health issues, as the communities along the creek depend directly on shrimps as a protein source.

Multivariate statistical techniques were applied for evaluation of temporal/ spatial variations and interpretation of a large complex water-quality data set of Shiroud River that discharges to southern part of Caspian Sea, Iran. Totally 16 parameters of water quality were monitored during 12 months at 8 sites in mountainous, flat and estuary areas. Factor analysis (FA) results showed that the first factor explained 25.76% of the total variance [comprise of electrical conductivity (EC), total dissolved solids (TDS), total hardness, calcium ion and water temperature levels]. The second factor called water quality indicator factor explained 13.99% [comprise of silicate, dissolved oxygen (DO) and pH levels], and the third factor called phosphate pollutant factor explained 10.72% (comprise of orthophosphate and total phosphorus (TP)). Additional factors were affected by part of nutrient, flow rate and general water quality, each of them recorded variance less than 10%. Discriminate analysis (DA) gave the best results for both spatial and temporal analysis. It has provided an important data reduction as it uses only four parameters (mean river depth, DO, NH4 +, and EC). Thus, DA allowed a reduction in the dimensionality of the large data set, explaining a few indicator parameters responsible for large variations in water quality. The present study shows the usefulness of multivariate statistical techniques for analysis and interpretation of complex data sets, and identifies probable source components in order to explain the pollution of Shiroud River.

Heavy metals in soils are of great environmental concern, in order to determine heavy metal content in the surface soil from the vicinity of an abundant railway servicing workshop and evaluate the contamination levels, 40 surface soil samples were collected and analyzed for Cu, Zn, Cd, Pb, Fe and Ni contents using atomic absorption spectroscopy. Soil texture, conductivity, pH, total organic content and cation exchange capacity were also measured. Heavy metals concentrations were determined after digestion of samples with aqua regia. In the investigated soils, the mean recorded concentrations of the heavy metals were 7.21 mg/kg f ff or Cu, 0.033 mg/kg for Ni, 0.087 mg/ kg for Cd, 48.52 mg/kg for Fe, 7.33 mg/kg for Zn and 26.66 mg/kg for Pb. The reported results indicate that the enrichment factors of the measured heavy metals were 2.26, >0.1, 0.39 and 3.47 for copper, nickel, zinc and lead respectively. I-geo (geoaccumulation index) values of the metals in the soils under study indicate that they are uncontaminated to slightly contaminate with nickel and iron but highly contaminated with copper and lead

The objective for the development of digital map of Dhaka Sylhet National Highway (N2) is to facilitate the highway transportation organizations. The Dhaka Sylhet National Highway (N2) is 284.9 km. On the basis of International Roughness Index (IRI), it’s 90.8% is good, 7.4% is Fair. The percent of poor section is 1.2 and has a bad section of 0.56%. The Dhaka Sylhet National Highway (N2) has four different pavement widths. Road-length of 272.3 km has a pavement width of 7.5 m. Pavement width 14 m has a road length of 10.4 km. Pavement width 10.2 m and Pavement width 10.3 m each has a road length of 1.1 km. In our study, three major bridges of N2 were suggested to easy traffic movement and safe handling of future traffic.

Effect of automobile pollution on the productivity of Crocus sativus was studied for one year time period (October 2005-April 2006). The parameters which were analyzed viz total chlorophyll, carotenoids, leaf area, plant height, corm size, corm weight, corm yield, biomass, flower production, and length of stigma and style, showed a remarkable decrease as compared to control. Total chlorophyll, carotenoids and leaf area decreased by approximately 40%, plant height by 36%, fresh biomass by 33%, dried biomass by 25%, corm yield by 29%,corm number by 32%, corm size by 33%,flower production by 33%,length of stigma+style by 23%,fresh weight of flower by 15% and dried weight of flower by 14% respectively.

The removal of chromate ions in trace concentration from tannery wastewater effluent using Ion exchange technique was carried out by varying parameters such as Chromate concentration and contact time. A maximum of 99% removal efficiency in the batch Ion exchange process was achieved over an equilibrium contact time of 20min. The equilibrium uptake of chromate was constant at average 9.8mg/L for initial chromate concentration of 10mg/L irrespective of the high concentration of chloride and sulphate ions in the wastewater. This inferred that the interference of these co-ions have no significant effect on the chromate uptake by the ions exchange resins used in this study. While, in the column experiments high effectiveness in the removal of chromate ions in trace concentration was observed. A removal efficiency of 98% of chromate removal was achieved even in the presence of high concentration of competing Ions. Obviously, this has shown the selectively of the resin towards the chromate uptake. The ion-exchange technique was found to be appealing for the removal of trace concentration of chromate when in the background there is high concentration of chloride and sulphate co-ions present in the tannery wastewater.

A new, local agro-industrial waste was valorized by chemical treatment and tested for its ability to remove cationic dye from aqueous solution. Tendu (Diospyros melanoxylon) leaves refuse, a solid waste from bidi industry which caused disposal problem, was studied as a biosorbent. Raw tendu waste (TLR), along with sulfuric acid carbonized tendu waste (TLR-CM) and tendu waste treated with dilute sulfuric acid (TLR-2N) were utilized as sorbent for uptake of crystal violet from aqueous solutions. Adsorption studies were carried out at various dye concentrations and contact times. It followed the pseudo-second-order kinetics and followed the Langmuir adsorption isotherm. Interestingly, milder acid treatment of the tendu waste enhanced biosorption, whereas drastic acid carbonization of tendu waste resulted in reduced adsorption of dye. The maximum adsorption capacities for crystal violet for TLR-2N, TLR and TLR-CM are 67.57, 42.92 and 22.47 mg/g respectively. Commercial activated carbon had maximum adsorption capacity for crystal violet of 151.52 mg/g. Thus a renewable solid waste with mild acid treatment can offer a cost effective alternative to activated carbon.

Among the environmental problems in Nigeria is the lack of proper management of municipal solid wastes (MSW), which is capable of releasing hazardous chemicals via leachate to the surrounding environment. In this study, the potential toxic effects of raw leachate obtained from Aba-Eku landfill (AERL) on Clarias gariepinus; and the microorganisms that may be present in the leachate were investigated. Physico-chemical analysis showed that the leachate contained toxic constituents. The 96 h LC50 obtained was 36.6%. Haematocrit %, erythrocyte number, haemoglobin concentration, leukocyte and lymphocyte number increased with increasing leachate concentration. Histopathological lesions were marked in the gills, kidney and liver of exposed fishes and were concentration dependent. A total of 112 bacterial isolates belonging to 17 genera were recorded from samples of AERL. Potential pathogens and toxin producing microorganism were identified. These observations are of prime health concern because there is no known containment or treatment system for the leachate generated from the study site. Our findings would be of assistance in the assessment of hazardous effects of chemicals from waste landfills discharged into the aquatic environment and in making policy on environmental waste management.

A study was performed in Hybrid Up flow Anaerobic Sludge Blanket (HUASB) and Anaerobic Filter (AF) reactors to compare the start-up time and optimum HRT required for the treatment of poultry slaughterhouse wastewater under similar loading conditions. Initially, the reactors were started at an OLR of 0.77 Kg COD/m3.d and HRT of 36 h. Loading rates were increased by reducing HRT 24, 16, 12, 10 and 8h which corresponds the OLR of 1.15, 1.74, 2.27, 2.74, 3.43 Kg COD/ m3.d. HUASB reactor showed TCOD and SCOD removal efficiencies of 80% and 86%, respectively at an optimum HRT of 10 h whereas AF reactor showed 70% (TCOD) and 79% (SCOD) at optimum HRT of 12 h. Reducing HRT beyond 10h in HUASB reactor shown sludge wash out and lower COD removal efficiencies of less than 80% and beyond 12 h in AF marked decreased efficiencies as low as 66%. HUASB and AF reactors took 120, 147 respectively, for complete start-up. The granules of 2-2.5 mm sizes were observed in HUASB and less than 1 mm were observed in AF with settling velocities ranging between 0.5-0.83 m/min and 0.5-0.65m/min, respectively. From Residence Time Distribution studies, dispersion numbers (<0.2) showed both the reactors attained plug flow regime. The present study revealed that the HUASB reactor has very good removal efficiency and less start-up time compared to that of AF reactor for the treatment of poultry slaughterhouse wastewater.

Active carbons were produced from bagasse, millet and sorghum straws by chemical activation with H3PO4. Carbon precursors with particle size of 1180 μm were used, in order to overcome difficulties caused by low density and high ash content. The influence of preparation conditions (temperature, residence time, and acid impregnation ratio) on the yield of the active carbons was examined. The impregnation ration which was controlled by varying the proportion of H3PO4 used for the activation had a strong influence on the yields of the carbons. The pyrolysis temperature was varied in the range 100-450 °C, but equilibrium yields of the active carbons were highest at 450C with optimum impregnation ratio of 13.6. The potential of the active carbons as efficient and economical means of removing mixture of aromatic hydrocarbon contaminants from water was indicated by the complete removal of objectionable odor from contaminated water samples containing 35.1348 mg/cm3 benzene and 34.8534 mg/cm3 Toluene, which are known carcinogens. Spectrophotometric determinations of the two solutes in the remediate water samples indicated slow but steady adsorption of the benzene/toluene mixture on the active carbons.

Qualitative and quantitative analyses of phyto- and zooplankton, and growth performance of Cyprinus carpio Linnaeus were done in earthen vats receiving compost, Diammonium Phosphate and vermicompost as direct application fertilizer were conducted. Significant differences were observed in the diversity and abundance of plankton in response to fertilization. The highest production of fish was obtained in the vats treated with vermicompost (3,970.56 kg/ha/90 days), followed by Diammonium Phosphate (3080.45 kg/ha/90 days), compost (1,952.64 kg/ha/ 90 days) and the lowest in the control (385.92 kg/ha/90 days). Vermicompost might be a cost-effective fertilizer in carp culture, replacing the expensive chemical fertilizer Diammonium Phosphate.

The province of Bushehr is located in southern area of Iran and north of Persian Gulf. Solid waste management in Bushehr’s villages was the aim of this research. For the sake of this study, 21 villages scattered all over the province were selected. Field studies showed that about 646 grams of residential solid waste per capita is generated in selected villages every day. There are 322 shops in chosen villages and total amount of commercial waste is about 3565 kilograms per day. The average amount of medical waste is about 7.8 kilograms per hygienic unit. Waste Composition in selected villages is: putrescible materials: 42.49%, construction and demolition: 11.7%, paper and cardboard: 8.77%, plastics: 8.24%, wood: 6.90%, metal: 6.08%, glass: 5.89%, rubber and leather: 5.1% and textile: 4.83%. According to this study, the main obstacle to recycling program is the unbiased collection of waste in rural area. It is recommended that for the first five year program, source separation includes degradable matter and dry wastes (paper, plastics and metals). Source separation of other components such as wood, rubber, glass and textile can be carried out in the second five year program. From the economical point of view, incineration with energy recovery can not be a good alternative for rural waste disposal in Bushehr province. Due to the low volume of degradable matter, land availability with low cost and easy access to labor force in rural areas, low cost technology composting is recommended. The quantity of waste generated in each village is not sufficient to be managed separately, thus a regional solid waste management must be defined to include adjacent villages.

It is known that native oil-degrading microorganisms are ubiquitous. They can be isolated from contaminated soils. In this study, biodegradation experiments were carried out to evaluate the efficiency of pollutant removal by adding the selected microorganisms. Five mixed cultures and 3 single bacteria strains, Pseudomonas sp., Arthrobacter sp. and Mycobacterium sp. were isolated from hydrocarbon-contaminated soils by enrichment on either crude oil or individual hydrocarbons, as the sole carbon sources. The strains were selected based on their ability to grow in medium containing crude oil, used engine oil or both. Their ability to degrade hydrocarbon contamination in the environment was investigated using soil samples contaminated with used engine oil. The mixed starter culture #1 degraded 66 % of aliphatic compounds in the engine oil, after 60 days of incubation. The mixed starter culture #5 removed 47 % of aromatic compounds during 60 days of incubation, which is the maximum efficiency among the starter cultures, in this study.