Effects of Electroplating Effluents on Growth, Heavy Metals Accumulation and Concentrations in Amaranthus viridis Lin.

Pollution in recent times has become prevalent due to industrial expansion,hence,releasing pollutants into the environ-ment.Thus,this study aimed at investigating the effects of effluents from electroplating companies on growth,heavy metals accumulation and concentrations in Amaranthus viridis.Seeds of A.viridis were obtained from the National Institute of Hor-ticulture,Ibadan.Loam soils were collected from Lagos State University and two samples of electroplating effluents were obtained from Oregun,Lagos.Seeds were sown,nursed,and transplanted in a uniform bucket filled with 5 kg loam soil and transplanted seedlings were treated with Effluent A(5 and 10%conc.)and Effluent B(5 and 10%conc.)and control respec-tively.Growth parameters such as plant height and so on were measured and plant samples harvested were analyzed for heavy metal concentrations using Atomic Absorption Spectrophotometer.Data collected were subjected to a one-way analysis of variance.Results revealed that Effluents A and B are highly acidic and above discharge limits.Also,the result revealed that 5%conc.of Effluents A and B had more effects on growth(p<0.05)of A.viridis across the harvests than 10%conc.in relation to control.This result showed that the effluent samples affect the growth rhythms of plants.Results further revealed vigorous–1–1 accumulation of the heavy metals:Zn(241.66µg kg±0.10 at third harvest in Effluent A:10%),Cu(68.25µg kg±0.23 at–1–1 first harvest in Effluent B:5%),Cr(500µg kg±0.90 in harvests at all concentrations.)and Ni(500µg kg±0.90 at third harvest in Effluent B:5%)and all these metals are far above the control and permissible limits of WHO/FAO recommenda-tions.From this study,it could be concluded that electroplating effluents had adverse effects on growth and increased metals’bioaccumulation in A.viridis.Therefore,the treatment of effluents to enhance an eco-friendly environment should be done.

Comparison of Pb,Cd Adsorption to Surface Coatings Developed in Natural Waters with that in Plant Effluents

The comparative studies of Pb and Cd adsorption to the surface coatings(Fe, Mn, Al oxides, organic materials, and associated minerals), which were developed on glass slides in five natural and two technical waters(plant effluents), were carried out under controlled laboratory conditions(mineral salts solution with defined speciation, ionic strength 0 05 mol/L, 25 ℃ and pH 6 0). The classical Langmuir adsorption isotherm was applied to estimating the equilibrium coefficients of Pb and Cd adsorption to the surface coatings. The results show that the maximum adsorption of Pb and Cd to the surface coatings mentioned above varied widely. There was a systemic increase in the maximum adsorption of Pb and Cd to the surface coatings with increasing the contents of Mn and Fe oxides in the surface coatings in significant correlation, respectively, not only highlighting the relative importance of the metal oxide fraction for Pb and Cd adsorption to the surface coatings developed in natural and technical water samples, but also implying the same adsorption mechanisms of Pb and Cd to the surface coatings developed both in natural and technical water samples.

Alkaline Hydrolysis to Reduce the AOX Concentrations in Effluents from Chlorination Treatment of Wool

Organic halogens generated in the chlorlnatlon treatment of wool are proven to be acutely toxic to human beings. Legislation on environmental pollution has become more and more stringent in recent years. So the chlorlnation treatment is faced with disuse. Alkaline hydrolysis is adopted to reduce the AOX (Absorbable Organic Halogen) concentrations in the effluents from the chlorlnatlontreatment under 40℃ and pH values 9, 10, 11 and 12. After treatment the reduction of AOX appears approximately 65%.

The Physico-Chemical Quality of Effluents of Selected Sewage Treatment Plants Draining into River Rwizi, Mbarara Municipality, Uganda

As population increases in urban areas, the domestic and industrial activities increase resulting in an increase in the volumes of wastewater and anthropogenic pollution, hence posing a threat to public health and environment. This study assessed the physical chemical quality of two main sewage plant effluents discharging into River Rwizi. Effluent water samples were analyzed for dissolved oxygen, colour, turbidity, total suspended solid, total iron, phosphates, alkalinity, magnesium, calcium carbonate, temperature, pH, ammonium, electrical conductivity, chloride and nitrates. Parameters were analyzed following standard methods of APHA (1985). The values obtained were compared with EPA (2001), NWSC (2015) and NEMA (1999) standards for waste water. Results showed that the mean values most of the parameters tested were higher than the recommended EPA, NWSC and NEMA standards. The mean colour was 1627.67°C and 1414.33°C in Kakoba and Taso sewage effluents respectively compared to EPA (20-150), NWSC (500) and NEMA (300) standards (p > 0.05). The mean alkalinity was 1390.17 mg/l and 1308.33 mg/l for Kakoba and Taso respectively compared with EPA (400) and NWSC (800) standards. DO had a mean concentration of 68.27 mg/l and 63.03 mg/l in Taso and Kakoba respectively compared to EPA and NEMA standard of 5 mg/l. Mg was 243.29 mg/l and 246.49 mg/l in Kakoba and Taso sewage effluents respectively compared to NEMA standard for waste water of 100 mg/l (p > 0.05). The mean pH was 8.26 and 8.16 in Taso and Kakoba sewage effluents respectively compared to NWSC and NEMA standard of 6.0 - 8.0. Phosphate mean concentration levels were 32.2 mg/l and 27.11 mg/l for Taso and Kakoba respectively compared to standards of EPA (0.5 - 0.7 mg/l) and NEMA (10 mg/l). NO3 was 10 mg/l and 5.83 mg/l in Kakoba and Taso sewage effluents respectively compared to NWSC maximum permissible limit of 5 mg/l. The mean NH4 concentration was 385.33 mg/l (Kakoba) and 50.0 mg/l (Taso) compared to the EPA guideline range (0.2 - 4 mg/l). Chloride (Cl) had a mean of 833.33 mg/l in Kakoba compared to EPA (250 mg/l), NWSC and NEMA (500 mg/l) standards. Therefore the study recommends for effective treatment of waste effluents from Kakoba and Taso sewage treatment plants before recycling in order to avoid pollution of river Rwizi.

Comparison of Different Sampling Techniques for the Identification of Aromatic Hydrocarbons from Fire Effluents

Huge amounts of various polymers are being used in many fields with numerous benefits. However, their great ability to ignition and rapid flame spreading make these materials dangerous for human life and properties due to the release of highly toxic combustion products. The present work aims to investigate several methods of sampling and identification of aromatic hydrocarbons produced by controlled burning of low-density polyethylene (LDPE) using a toxicity tube furnace. Five different sampling methods were used: solid phase micro extraction (SPME), syringe, tedlar bags, sorption tubes, and gas-solution absorbers (midget impingers). The produced hydrocarbons were analysed by gas chromatography coupled to mass spectrometry with and without pyrolysis. Among the tested techniques, the most convenient sampling method was using syringe with a glass vessel which allowed detection of the highest amount of aromatic hydrocarbons at both 800°C and 600°C, and then followed by SPME. On the other hand, the use of gas-solution absorber (midget impinger) showed poorer results. Regarding the use of tedlar bags and sorption tubes, they did not give satisfactory results. Several carcinogenic or possibly carcinogenic compounds were identified in the combustion products, such as benzene, naphthalene, anthracene and pyrene.

Heavy Metals Accumulation in Soil Irrigated with Industrial Effluents of Gadoon Industrial Estate, Pakistan and Its Comparison with Fresh Water Irrigated Soil

Wastewater mixed with industrial effluents is used for irrigation in Gadoon Industrial estate and thus contaminating soil. This soil was tested for heavy metal content by using atomic absorption spectrophotometer (perkin elmer 700) and compared with control soil irrigated with tube well water at seven selected spots. Accumulation of the toxic metal was significantly greater in the soil irrigated with industrial effluent than control soil (p < 0.05). Manganese (Mn) was the most significant pollutant, accumulated up to 9.95 ppm in the soil irrigated with industrial waste water. It was found that the samples were containing Zn in the range of 1.596 - 6.288, Cu 0.202 - 1.236, Co 0.074 - 0.115, Ni 0.0002 - 0.544, Cr 0.243 - 0.936, Mn 3.667 - 9.955 and Pb 0.488 - 1.259 ppm. No sample was containing the heavy metal above the critical level mentioned in typical and unsafe heavy metal levels in soil.

Isotherm and Thermodynamic Studies on the Bio Adsorption of Textile Industrial Effluents onto Chitosan Nanoparticle from Macolor Niger (White Snapper)

Fish scale wastes are generally discarded in the environment through fish processing industries and local market vendors. It is one of the excellent and efficient renewable bioproducts. Consequently, a number of bioactive compounds have been identified including bioactive peptides, collagen, chitosan, and gelatin which are commercially marketed. The current study involves the extraction and generation of chitosan nanoparticles from fish scales. The synthesized chitosan nanosubstances were categorized by Field Emission Scanning Electron Microscopy (FESEM). The viability of utilizing fish scales as an economical bio-adsorbent for elimination of textile dye was studied on industrial effluent. Fourier transform infrared spectroscopy (FTIR) was used to study the dye adsorption of chitosan nanoparticles before and after the dye treatment. With chitosan nanoparticle treatment of the textile effluents, removal of COD was improved to 80% and the turbidity removal efficiency was improved up to 90%. Thus, the present study provides an excellent bio-adsorbent chitosan nanoparticle generated from fish scales which have potential application as an adsorbent in bioremediation like wastewater treatment.

Removal of Carbonyl-Containing Effluents by Photodegradation Using β-Carotene Embedded onto Zinc Oxide Particles

Environmental pollution especially in the form of effluent wastewater from industries has been a major challenge. Carbonyl-containing organic standards and sewage sample were effectively photo degraded. ZnO nanoparticles were prepared by emulsification of zinc-carbamate solution using 1 N NaOH and grafted chemically by Molecular Layer Doping method at 180 °C with β-carotene extracted using methanol by refluxing at 50 °C at varying concentrations. Intrinsic and grafted β-carotene ZnO were characterized using FTIR (Fourier transform infrared spectroscopy) and their spectra differed in an additional peak at around 1,435 nm corresponding to the organ metallic bond Zn-C. UV-Vis spectra of the two composites indicated a blue shift in the grafted samples. This translated to a reduced band gap from 3.5 eV to 3.4 eV. Comparison in the rates of photodegradation of pure organic compounds, organic effluents and color change of dyes was in the order 1% grafted, 0.5% grafted, intrinsic ZnO and blank sample. When 10.0 mL of sewerage water was photo degraded using both sunlight and UV-Lamp for 40 minutes, the amount of carbonyls present decreased by 28.5% for β-carotene grafted ZnO, 24.5% for intrinsic ZnO and 0.6% for a blank sample.

Haematological and Hepatic Responses of the African Catfish Clarias gariepinus to Sublethal Exposure of Industrial Effluents from Ologe Lagoon Environs,Lagos,Nigeria

The present study is on the haematological and hepatic responses of the African catfish fingerlings Clarias gariepinus to sublethal toxicity of industrial effluents(IE)from the environment of Ologe Lagoon,Lagos,Nigeria.The fish were cultured in five concentrations of industrial effluents:0%(control),5%,15%,25%,and 35%.Trials were carried out in triplicates for twelve(12)weeks.The culture system was a static renewable bioassay and was carried out in the fisheries laboratory of the Lagos State University,Ojo-Lagos.Weekly physico-chemical parameters:Temperature(°C),pH,conductivity(ppm)and dissolved oxygen(DO in mg/L)were measured in each treatment tank.Haematological parameters:packed cell volume(PCV),red blood cells(RBC),white blood cell(WBC),neutrophil and lymphocytes etc.,and hepatological alterations were measured after 12 weeks.The physico-chemical parameters showed that the pH ranged from 7.82±0.25~8.07±0.02.DO ranged from 1.92±0.66~4.43±1.24 mg/L.The conductivity values increased with increase in concentration of I.E.While the temperature difference remained insignificant with mean value range between 26.08±2.14~26.38±2.28.The DO showed significant differences at p<0.05.Though survival was 100%during the sublethal study,haematological results showed that C.gariepinus had PCV ranging from 13.0±1.7~27.7±0.6,RBC ranged from 4.7±0.6~9.1±0.1,and neutrophil ranged from 26.7±4.6~61.0±1.0 amongst others.The highest values of these parameters were obtained in the control and lowest at 35%.While the reverse effects were observed for WBC and lymphocytes,the liver shows normal liver cells in the control(0%),but at higher toxic levels,there were:vacoulation,destruction of the hepatic parenchyma,tissue becoming eosinophilic(i.e.tending towards Carcinogenicity)and severe disruption of the hepatic cord architecture.This study therefore shows that disposal of effluents into the aquatic environment affects the health of fishes by impairing normal hepatic functions and hindering vital physiological processes if exposure continues for a long period of time(sublethal effect).

Reduction of Infectious Cryptosporidium and Microbial Indicators in Wastewater Effluents by Disinfection with UV Irradiation or Chlorine

When properly treated, domestic wastewater should be considered a potential reliable water source in arid and semi-arid regions of the world for none-potable purposes. In Israel and other countries around the world, the main biological standards for water reuse are based on fecal coliform (FC) and turbidity. Furthermore, in secondary treatment, the Israeli standard for water reuse and for unrestricted irrigation comprises additional steps such as filtration and chlorination. The present study was conducted to compare the reduction efficiency of live Cryptosporidium oocysts in wastewater effluents by filtration and disinfection by either UV irradiation or chlorination. Cryptosporidium oocysts infectivity reduction was compared to those of the conventional microbial indicators (FC). The study was conducted in two full-scale wastewater treatment plants. The average concentration of FC and Cryptosporidium in secondary effluent was 2.8 × 105 cfu/100ml and 5.7 oocysts/10L, respectively. Infectious Cryptosporidium oocysts were detected in 2 out of 7 secondary effluent samples (28.5%). Infectious Cryptosporidium oocysts were not detectable in UV disinfected tertiary effluent. Conversely, 3 out of 7 (42.8%) tertiary effluent samples disinfected with chlorine were positive for infectious Cryptosporidium oocysts. The results of this study revealed that the application of a multi barrier treatment, including UV irradiation, for the reduction of Cryptosporidium oocysts and microbial indicators could improve tertiary effluent safety for unrestricted irrigation and other reuse purposes.

Ways of Analysis of Fire Effluents and Assessment of Toxic Hazards

Fire effluents, in most cases, have an adverse effect on human health and the environment. Exposure to some compounds may show both acute and chronic toxicity. There is a lack of knowledge on the effect of organic products on the human body in terms of the rate of organic material production in fires and their degree of toxicity. Thus, there is a need to expand the scope of studies about the organic products generated from fires and improve the methods of assessment to be included as part of fire hazard assessment. Different factors can be contributed to this lack of knowledge. For example, the composition of organic products generated from fires changes progressively and rapidly with progression of combustion and in a manner that is dependent on the fire condition. It is difficult to identify individual organic compounds produced during combustion. Another key factor is the lack of suitable instruments for measuring organic products generated from a fire. Also, the lack of procedures that are used to evaluate the lethal concentration limits and the lethal dose for a broad range of organic compounds generated from a fire may be another important factor which can be contributed to this lack of knowledge.

Microbiological Quality of the Effluents Produced by the University and Hospital Centres in the Department of Littoral, Republic of Benin

Introduction: The effluents generated by hospital activities pose a potential danger to health and the environment. This study aimed to study the microbiological quality of the effluents produced by the university and hospital centres of Littoral department. Methods: This was a descriptive cross-sectional study of 60 samples of hospital effluents from sewage treatment plants and septic tanks carried out during the period from April to June 2019. Samples at the station were made at the entrance and exit of the station. Samples for microbiological analysis were collected in pre-sterilized 500 mL glass bottles. Samples were kept between at 2&#176;C - 8&#176;C and in the dark to ensure satisfactory preservation. ANOVA one-way analysis of variance was performed for each microbiological parameter and principal component analysis (PCA) was also performed. Results: The bacteriological analyses carried out on the 60 samples taken showed a significant microbiological load. In fact, the bacteriological parameters measured and compared to the pollutant release standards in the environment show that the number of germs identified is above the recommended guideline values. The average values for total coliforms, faecal coliforms, faecal streptococci and staphylococci were: 3.91 × 105 UFC/100 mL, 0.52 × 105 UFC/100 mL, 3.92 × 105 UFC/100 mL and 1.36 × 105 UFC/100 mL, respectively. The most isolated bacteria were: Klebsiella pneumoniae, Klebsiella oxytoca, Escherichia coli, Enterococcus faecalis, Enterobacter cloacae, Pseudomonas horizyhabitans, Staphylococcus aureus and Staphylococcus saprophyticus. Most strains were resistant to at least 3 families of antibiotics (beta-lactams, aminoglycosides and fluoroquinolones). Conclusion: These effluents therefore present health and environmental risks. It is of utmost importance to develop methods for the treatment of these effluents before their release into the natural environment.

Acute effects of chlorpyryphos-ethyl and secondary treated effluents on acetylcholinesterase and butyrylcholinesterase activities in Carcinus maenas

The acute effects of commercial formulation of chlorpyrifos-ethyl （Dursban ） and the secondary treated industrial/urban effluent （STIUE） exposure on acetylcholinesterase （ACHE） and butyrylcholinesterase （BuChE） activities in hepatopancreas and gills of Mediterranean crab Carcinus maenas were investigated. After 2 d of exposure to chlorpyriphos-ethyl, the AChE activity was inhibited in both organs at concentrations of 3.12 and 7.82 μg/L, whereas the BuCHE was inhibited only at higher concentration 7.82 μg/L of commercial preparation Dursban~. The exposure of crabs to Dursban （3.12 μg/L） showed a significant decrement of ACHE activity at 24 and 48 h, whereas the BuChE was inhibited only after 24 h and no inhibition for both enzymes was observed after 72 h. Moreover, a significant repression of AChE activity was observed in both organs of C. maenas exposed to 5% of STIUE. Our experiments indicated that the measurement of AChE activity in gills and hepatopancreas of C. maenas would be useful biomarker of organophosphorous （OP） and of neurotoxic effects of STIUE in Tunisia.

Microalgal Cultivation in Secondary Effluents:Enhancement of Algal Biomass,Nutrient Removal,and Lipid Productivity

The growth performance,nutrient removal,lipid accumulation and morphological changes of Cyanobacterium aponinum OUC1 and Scenedesmus obliquus which were cultured in secondary effluents from two wastewater treatment plants:Tuandao Wastewater Treatment Plant(ETD)and Licun River Wastewater Treatment Plant(ELR)were investigated.The results showed that both C.aponinum OUC1 and S.obliquus have superior growth performances in both undiluted effluents,while the better of them was that in ETD effluent,with cell densities of C.aponinum OUC1 and S.obliquus increased by 159%and 66%over that of BG11(control),respectively.Regarding nutrient removal,S.obliquus could completely remove inorganic phosphorus,and decrease ammonia nitrogen in ETD effluent by 81%.In addition,both C.aponinum OUC1 and S.obliquus cultivated in ETD exhibited extraordinary potential for biofuel production,increasing lipid productivities by 133%and 89%of that cultivated in ELR,respectively.As to ultrastructural changes,the differences in the lipoidal globules and glycogen granules of S.obliquus and C.aponinum OUC1 among the ETD and ELR treatments were mostly related to phosphorus limitations.The findings from this research reveal the probability using the secondary effluents as cultivation media to enhance algal biomass,nutrient removal and lipid productivity.

THMs Precursor Removal Efficiency from Different Wastewater Treatment Technologies Effluents

Treated wastewater is one of the critical practices of sustainable water management. In Palestinian authority region different wastewater technologies are used to produce variety of effluents that are potentially suitable for different purposes. In this study, these different treated wastewater effluents were characterized chemically, biologically, and physically. Results showed that some of these effluents neither comply with Palestinian nor with other global effluent discharge guidelines. Chemical reactivity of five different treated wastewater effluents with chlorine was measured by determining their chlorine demand and total trihalomethane formation potential (TTHMFP). Results showed that different wastewater effluents chemical reactivity with chlorine and TTHMFP is not only dependent on wastewater treatment technology but also is affected by original water source from which was the water emerged. In all cases, measured THMs superseded acceptable drinking water limits. This would indicate responsibility of high percentage of cancer, hepatic and renal diseases among the local people.

Bio-Geo-Chemical Characterization of Bangladeshi Textile Effluents

Recently industrialization has become one of the most promising contributors for economic development of Bangladesh. However, at the same time, industrial pollution has turned into one of the major problems for human being as well as for the environment. In order to understand the effect of textile effluent (TE) on environmental pollution, TE samples collected from North-west part of the capital of Bangladesh, Dhaka (Savar, Ashulia and Tongi area) were characterized biologically, biochemically and biophysically. Eight potential microorganisms were isolated (3 bacteria and 5 fungi) from the collected TE and two of them were used to de-colorization of TE significantly by bioremediation process. Among the various parameters checked here, some physicochemical properties like TDS, COD, BOD, DO and heavy metals like Cd and Cr were detected in quite high amounts. Altogether, our results indicate that TE is one of the serious pollutants, which could damage environment as well as water body severely.

Analysis of Physico-Chemical Characteristics of Effluents from Beverage Industry in Ethiopia

Beverage industries are one of the most polluting industries producing huge amount of wastewater effluents. These industries have been recognized to cause pollution by discharging effluent into receiving environment especially to the nearby rivers. The aim of this study is to determine the status of waste water effluent discharge of beverage industry in Ethiopia. Samples were collected from 8 beverage industries’ wastewater effluent discharge end pipe and examined for different physico-Chemical parameters such as: COD, BOD5, TSS, ammonia, total nitrogen, PH and phosphate. The observed values were ranged between 9 - 397.5 mg/L for TSS, 0.185 - 69.7 mg/l for phosphate, 0.265 - 71 mg/l for ammonia, 226 - 1975 mg/l for COD, 15 - 576 mg/L for BOD, 4 - 86.6 mg/l for total nitrogen and 5.21 - 12.37 for PH. The finding of the study revealed that most of the beverage industries were extremely high amount of total suspended solids (TSS), BOD and COD effluent discharge were found above the Ethiopian beverage industry effluent discharge limit value. Half of the sampled beverage industries’ effluent discharge of PH, total nitrogen, ammonia and phosphate were found within the limit value while the rest of the industries are still discharging their effluent above the national standard limit value. The continuous discharge of effluents into rivers without any additional treatment raises the level of pollution and toxicity, which have significantly adverse impact on the aquatic environment.

Chemical Composition of Industrial Effluents and Their Effect on the Survival of Fish and Eutrophication of Lake Hawassa, Southern Ethiopia

Growing trends in industrialization in Ethiopia have raised concerns about pollution of water bodies particularly of lakes. This study was therefore conducted to 1) characterize the chemical contents of major industrial effluents (namely textile ceramic and soft drink factories) that reached Lake Hawassa and 2) investigate the effects of the above mentioned factory effluents on survival of larvae fish and growth of algae. Effluent samples were collected from the outlet lagoons of each factory in December, 2009. Then, effluent samples were analyzed for total N, NO3-N, NH4-N, S2-, , , COD, total dissolved solids (TDS) and heavy metals at the federal Environmental Protection Agency (EPA) Laboratory, Addis Ababa. The experiments on the impact of effluents on survival of fish larvae and growth of algae were conducted using six concrete paved ponds (with different concentration of effluent). The results of chemical analysis showed that textile effluent had high COD (nearly 3 times higher), TDS (19 times higher) as well as (39 times higher) than the maximum permissible limits (MPL) set by Environmental Protection Authority (EPA). Among heavy metals, Zn and Fe of textile effluent were much higher (41 and 1.5 times higher, respectively) than the MPL set by EPA. Ceramic effluent also contained high concentration of (24.5 times), S2-, (2 times) and Zn (14 times) exceeding the limit of EPA. Regarding soft drink factory, high values of COD, and Zn were found in the effluent than the limit specified by EPA. The biological treatment lagoons of the respective source were not effective since the effluents were taken from the last treatment lagoon (outlet lagoon) and some of the measured parameters were higher than MPL. Results of the pond experiment showed that 5%, 10% and 20% concentration levels of the HTF effluent killed significantly high proportion of the fry (65%, 86.8% and 88.7%, respectively). In contrast, fry mortality in ceramic and soft drink effluent treatments, even at 10 and 20% concentration levels, stayed nearly below 10%, which were not far off from the mortality of the control groups. Algal biomass in the treated ponds varied with the type of effluent treatment and concentration level. Compared with the first day, chlorophyll “a” concentration measured on the 7th day had increased by 51%, 48%, 74%, 27% and 31% at 0%, 1%, 5%, 10% and 20% concentrations, respectively of textile effluent. The 5% treatment level of textile effluent caused the highest rate of algal growth above the growth rate observed in the control pond, but further increased in concentration to 10% and 20% resulted in a lower growth of algae than in the control pond. Therefore, textile effluent may boost up algae growth at lower concentrations (~5%) but at higher concentration levels its toxic effect may become inhibitory. Regarding the effluent of soft drink factory, algal growth progressively diminished with increasing concentration of the effluent. The overall change (between initial and day 7) in chlorophyll “a” concentration was highest in the control pond (36.2%) and decreased with increasing effluent concentration (1% to 20%) from 21.7% to -9.4%. On the other hand, algal growth under ceramic effluent treatment was comparable with that observed in the control pond.

The New Methods for Purifying the Industrial Effluents by Submerged Biofilm Reactors

Life on the earth is dependent on dynamic interactions between its physical, chemical and biological components. In fact, all the individual processes are responsible for regulating the environmental equilibrium which can provide biosphere for multiple forms of human life. In order to overcome on shortcomings, the use of immobilized cell bioreactor technology which provides a valuable effective for treatment of waste water is discussed. An immobilized system which in this matter is applied is about absorbed or captured microorganisms in a solid substratum to retain them in a reactor or analytical system. The multiply of these immobilized cells is done when by nutrients be supplied and then migrate to the surfaces which are referred to biofilms. The biofilms can be developed on various support systems such as polypropylene pall, rocks, sands, charcoal, ceramics, and glass beads. The controllable reaction vessels which are used for these colonized surfaces are referred to bioreactors. Bioreactors in both up flows and down flows mode which use of either batch or continuous processes principle can be operated. Synchronic with development in biotechnology, there is also an extensive development in the field of bioreactors like: pumped tower loop reactor (PTLR), liquid impelled loop reactor (LILR), multipurpose tower bioreactor (MTB), fluidized-bed and packed-bed bioreactor, that in this article are discussed them.

Environmental Contamination by Industrial Effluents and Sludge Relative to Heavy Metals

Oman is located in the tropic of Cancer with extremely hot temperatures ranging between 15&deg;C-25&deg;C in winter and 30 - 48 in the summer with low rainfall. Most of the water source is desalinated seawater. Recycling of sewage effluent is a common practice used for farming, public parks and industry. The dried sludge product is used as fertilizer. The highly concentrated sludge with heavy metals is either incinerated or buried in landfills. Heavy metals were analyzed and compared in treated sewage effluent (TSE), slurry sludge, dried sludge, landfill and underground water. Heavy metal concentrations were analyzed using the inductive coupled plasma optical emission spectrometer (ICP-EOS). All samples contained the same heavy metals with different concentrations. The heaviest concentrations were Zn, Cu, Cr and Ni with traces of V, Cd, Pb and Ba. TSE and sludge were the main sources of landfill and underground water contamination. Due to water evaporation, heavy metals concentrations in sludge were higher compared to TSE and underground water. Dried sludge and landfill contained higher concentrations than the others. Based on this investigation, it appears that the source of heavy metals is from TSE originated mainly in industries. If the infiltration of heavy metals to soil and underground water continues, it will be a serious environmental and health problem in the future.