Home About us Contact
|
Home About us Contact | ||
|
|
||
Treated Wastewater (treated + wastewater)
Selected AbstractsEvaluating wastewater-induced plant genotoxicity using randomly amplified polymorphic DNAENVIRONMENTAL TOXICOLOGY, Issue 1 2008K. M. Swaileh Abstract Wastewater often contains genotoxic substances that can resist different stages of the treatment process. In the present study, randomly amplified polymorphic DNA technology was applied to evaluate the genotoxic effects of wastewater (treated and raw) irrigation on oat plants (Avena sativa). RAPD profiles obtained showed that both treated and raw wastewater (RWW) were having genotoxic effects on oat plants. This was apparent by the appearance/disappearance of bands in the treatments compared with the control plants. From the 15 primers used, 186 bands were obtained with an average of 12.4 bands per primer. Irrigating plants with RWW caused 51 new bands to appear and 19 to disappear. Treated wastewater (TWW) caused only 16 new bands and the loss of 17 bands. This makes TWW less genotoxic than RWW. The Euclidean distances shown on the dendrogram, revealed the presence of two clusters according to dissimilarity values. One cluster contained the control plants and those irrigated with TWW, whereas the second contained the plants irrigated with RWW. Similarity indices calculated between the treatments and the control plants showed that the control and the plants irrigated with TWW had a similarity index of 0.87, the control and plants irrigated with RWW 0.73 and between the treatments 0.75. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. [source] The performance of constructed wetlands for, wastewater treatment: a case study of Splash wetland in Nairobi KenyaHYDROLOGICAL PROCESSES, Issue 17 2001Daniel Muasya Nzengy'a Abstract The performance of a constructed wetland for wastewater treatment was examined for four months (December 1995 to March 1996). The study area, hereby referred to as the Splash wetland, is approximately 0·5 ha, and is located in the southern part of Nairobi city. Splash wetland continuously receives domestic sewage from two busy restaurants. Treated wastewater is recycled for re-use for various purposes in the restaurants. Both wet and dry season data were analysed with a view of determining the impact of seasonal variation on the system performance. The physical and chemical properties of water were measured at a common intake and at series of seven other points established along the wetland gradient and at the outlet where the water is collected and pumped for re-use at the restaurants. The physico-chemical characteristics of the wastewater changed significantly as the wastewater flowed through the respective wetland cells. A comparison of wastewater influent versus the effluent from the wetland revealed the system's apparent success in water treatment, especially in pH modification, removal of suspended solids, organic load and nutrients mean influent pH = 5·7 ± 0·5, mean effluent pH 7·7 ± 0·3; mean influent BOD5 = 1603·0 ± 397·6 mg/l, mean effluent BOD5 = 15·1 ± 2·5 mg/l; mean influent COD = 3749·8 ± 206·8 mg/l, mean effluent COD = 95·6 ± 7·2 mg/l; mean influent TSS = 195·4 ± 58·7 mg/l, mean effluent TSS = 4·7 ± 1·9 mg/l. As the wastewater flowed through the wetland system dissolved free and saline ammonia, NH4+, decreased from 14·6 ± 4·1 mg/l to undetectable levels at the outlet. Dissolved oxygen increased progressively through the wetland system. Analysis of the data available did not reveal temporal variation in the system's performance. However, significant spatial variation was evident as the wetland removed most of the common pollutants and considerably improved the quality of the water, making it safe for re-use at the restaurants. Copyright © 2001 John Wiley & Sons, Ltd. [source] Industrial wastewater treatment in a membrane bioreactor: A reviewENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 1 2004B. Marrot Abstract This paper provides a detailed literature review of wastewater treatment in a membrane bioreactor process (MBR) with special focus on industrial wastewater treatment. MBR systems are compared with conventional wastewater treatment systems. The characteristics of the bioreactor treatment process (biomass concentration and floc size, organic and mass loading rates, etc.) are examined. The membrane separation of microorganisms from the treated wastewater is discussed in detail. Problems of membrane fouling and membrane washing and regeneration, linked to activated sludge characteristics, are examined. © 2004 American Institute of Chemical Engineers Environ Prog, 23: 59,68, 2004 [source] Treatment of paper and pulp wastewater and removal of odorous compounds by a Fenton-like process at the pilot scaleJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 8 2006José L Tambosi Abstract A Fenton-like process, involving oxidation and coagulation, was evaluated for the removal of odorous compounds and treatment of a pulp and paper wastewater. The main parameters that govern the complex reactive system [pH and Fe(III) and hydrogen peroxide concentrations] were studied. Concentrations of Fe(III) between 100 and 1000 mg L,1 and of H2O2 between 0 and 2000 mg L,1 were chosen. The main mechanism for color removal was coagulation. The maximum COD, color and aromatic compound removals were 75, 98 and 95%, respectively, under optimal operating conditions ([Fe(III)] = 400 mg L,1; [H2O2] = 500,1000 mg L,1; pH = 2.5; followed by coagulation at pH 5.0). The biodegradability of the wastewater treated increased from 0.4 to 0.7 under optimal conditions and no residual hydrogen peroxide was found after treatment. However, partially or non-oxidized compounds present in the treated wastewater presented higher acute toxicity to Artemia salina than the untreated wastewater. Based on the optimum conditions, pilot-scale experiments were conducted and revealed a high efficiency in relation to the mineralization of organic compounds. Terpenes [(1S)-,-pinene, ,-pinene, (1R)-,-pinene and limonene] were identified in the wastewater and were completely eliminated by the Fenton-like treatment. Copyright © 2006 Society of Chemical Industry [source] Olive oil mineral content of two local genotypes as influenced by recycled effluent irrigation under arid environmentJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 12 2009Khaled M Al-Absi Abstract BACKGROUND: An alternative plan for saving scarce water could include use of non-conventional water resources such as reclaimed wastewater originating from wastewater treatment plants. The main health risks are associated with contamination of crops by wastewater due to its chemical composition. Therefore, the effect of recycled effluent irrigation was investigated on mineral composition and quality of olive oil of two local olive cultivars under field conditions during two complete cycles. RESULTS: The treated wastewater used in this study was taken from the HUIE Wastewater Treatment Plant. This water is mainly generated by textile firms, mixed with municipal domestic effluent. The analysis of the effluent indicated that element concentrations fall within the permissible range in irrigation water used for plants. The concentrations of mineral composition were relatively higher in olive oils irrigated with treated wastewater but lower than the maximum permissible concentration. Concentrations ranged from 8.91 to 26.16 mg kg,1 for Ca; 6.25,16.11 mg kg,1 for Na, 53.20,111.76 mg kg,1 for K, 0.19,0.36 mg kg,1 for Zn, 0.97,1.46 mg kg,1 for Mn and 0.07,0.13% for Cl. No statistically significant differences were found between the oil quality indices (peroxide and acidity). CONCLUSION: These results indicate that this kind of effluent is suitable for irrigation of olive genotypes grown for oil purposes. Copyright © 2009 Society of Chemical Industry [source] Use of repetitive DNA sequences to determine the persistence of enteropathogenic Escherichia coli in vegetables and in soil grown in fields treated with contaminated irrigation waterLETTERS IN APPLIED MICROBIOLOGY, Issue 5 2006K. Ibenyassine Abstract Aims:, Fresh fruits and vegetables are increasingly recognized as vectors for food-borne illness. On farm contamination through contaminated irrigation water is considered likely source of the pathogen for several outbreaks. The purpose of this study is to investigate the possible similarity of strains of Escherichia coli isolated from the soil and vegetables irrigated by treated wastewater. Methods and Results:, Seventy-five strains of enteropathogenic Escherichia coli isolated from vegetables, soil and irrigation water were tested for sensitivity to antibiotics and shown to be sensitive. The result of enterobacterial repetitive intergenic consensus (ERIC)-PCR shows similarities between analysed strains isolated from the three different samples. Moreover strains of E. coli isolated from vegetables over different periods of time have the same ERIC-PCR profile. Conclusions:, The isolated strains of enteropathogenic E. coli can persist in soil and in vegetables growing in fields treated with contaminated irrigation water for an extended period of time. Significance and Impact of the Study:, Contaminated irrigation water can transport pathogenic bacteria, which persists in the soil for a long period of time and contaminates the vegetables growing in the field irrigated by this contaminated water. [source] | |||||||||||||