This study covers a thorough characterisation of landfill leachates emerging from a sanitary landfill area. The landfill leachates were obtained in the acidic stage of landfill stabilisation. Their organic content was high as reflected by the high BOD5 (5 day biological oxygen demand) and COD (chemical oxygen demand) values. They were also highly polluted in terms of the parameters TKN (total Kjeldahl nitrogen), NH4-N, alkalinity, hardness and heavy metals. Nickel was present in these wastewaters at a significant concentration. With regard to the high heavy metal content of these wastewaters, several physicochemical removal alternatives for the heavy metals Cu, Pb, Zn, Ni, Cd, Cr, Mn and Fe were tested using coagulation, flocculation, precipitation, base addition and aeration. Additionally, COD removal and ammonia stripping were examined. Co-precipitation with either alum or iron salts did not usually lead to significantly higher heavy metal removal than lime alone. The major methods leading to an effective heavy metal removal were aeration and lime addition. Nickel and cadmium seemed to be strongly complexed and were not removed by any method. Also lead removal proved to be difficult. The results are also discussed in terms of compliance with standards. 相似文献
Emissions from landfills via leachate and gas are influenced by state and stability of the organic matter in the solid waste
and the environmental conditions within the landfill. This paper describes a modified, ecologically sound waste treatment
technique, where municipal solid waste is anaerobically treated in a lysimeter-scale landfill bioreactor with leachate recirculation
to enhance organic degradation. The results demonstrate a substantial decrease in organic matter (BOD 99%, COD 88% and TOC
81%) and a clear decrease in nutrient concentrations especially ammonia (85%) over a period of 1 year with leachate recirculation. 相似文献
The biologically treated distillery effluent (BTDE) contains intense colour, high total dissolved solids (TDS), chemical oxygen
demand (COD) and biochemical oxygen demand (BOD). These properties even after primary, secondary and tertiary treatments contain
high concentrations of TDS, COD and BOD. The paper highlights the safe disposal and treatment of BTDE on land through High
Rate Transpiration System (HRTS). HRTS is a zero discharge, low cost, high-tech method for improving the quality of BTDE for
potential reuse. The experiments conducted at bench and pilot scale showed that HRTS having coconut husk as a bedding material
could successfully treat the BTDE with a hydraulic load of 200 m3 ha−1 day−1 having BOD of 100 mg l−1 and 500 m3 ha−1 day−1 having BOD of 500 mg l−1 with average COD load of 0.686 and 2.88 ton ha−1 day−1 during the post and pre monsoon periods respectively. There was no significant increase in the organic carbon of the soil
irrigated with BTDE. The concentrations of various pollutants analyzed in the leachate were within the prescribed limit for
the drinking water sources. The colour removal was 99 to 100% and BOD and COD were possible to treat with optimum hydraulic
loading of BTDE through HRTS planted with Dendrocalamus strictus. 相似文献
Biochemical oxygen demand (BOD) of the leachates originally from the different types of landfill sites was studied based on the data measured using the two manometric methods. The measurements of BOD using the dilution method were carried out to assess the typical physicochemical and biological characteristics of the leachates together with some other parameters. The linear regression analysis was used to predict rate constants for biochemical reactions and ultimate BOD values of the different leachates. The rate of a biochemical reaction implicated in microbial biodegradation of pollutants depends on the leachate characteristics, mass of contaminant in the leachate, and nature of the leachate. Character of leachate samples for BOD analysis of using the different methods may differ significantly during the experimental period, resulting in different BOD values. This work intends to verify effect of the different dilutions for the manometric method tests on the BOD concentrations of the leachate samples to contribute to the assessment of reaction rate and microbial consumption of oxygen. 相似文献
The market place is considered to be an important centre of daily life of campus community. In India, as in Europe and the
USA, other forms of shopping have emerged significantly and now predominate, for instance department stores and supermarkets.
Though, it is suffered from poor waste management, but the place could be a potential source for obtaining non-conventional
energy. The present study examined the quality of market waste management of the Indian Institute of Technology Campus along
with the feasibility of biogas production from leachate generated in the waste. Solid wastes from different storage locations
of the market place were collected and analyzed. The characteristics of solid wastes were found to be degradable in nature.
The wastes, composed of 85% of vegetable origin, were placed in a container and water was added to to generate leachate. The
self-purification efficiency of leachate was also studied in the Indian environment and compared with research findings in
the USA under an identical moisture application rate. Leachate characterization was investigated both under saturated and
submerged conditions. The treatability of leachate was studied in a laboratory-scale up-flow anaerobic filter with hollow
burnt clay rings as packing media. It was observed that 4,000–6,000 mg/l would be the optimum range of inlet chemical oxygen
demand (COD) concentration for leachate treatment because of the inhibitory effect of ammonia, sulphide, volatile fatty acids
and toxic metals in high concentrations at higher strengths of leachate. The gas production rate was found to be at a maximum
at 38°C and containing 70–75% methane. From experimental data, it was revealed that 83% COD was removed with input COD concentration
of 5,475 mg/l at 2 days hydraulic retention time with biogas yield coefficients of 0.61. The present study also investigated
the removal efficiency of chloride, ammonia, sulphide and nitrate. 相似文献
The work describes the physicochemical analysis of the water samples collected from Lahore Canal to evaluate pollution load at different points of the canal. Different physical and chemical pollutants such as temperature, pH, electrical conductivity, total dissolved and suspended solids, turbidity, chlorides, sulphates, nitrates, oils and grease, dissolved oxygen, chemical oxygen demand and biological oxygen demand (BOD) were analysed. The data was analysed through analysis of variance, which showed that the p values for dissolved oxygen (DO), chemical oxygen demand (COD), BOD, electrical conductivity, total dissolved solid (TDS), total suspended solid (TSS), turbidity, oil and grease, sulphates, and nitrates are <0.05, while p value of temperature, pH, and chlorides are 1.000, 0.984, and 0.070, respectively, which are >0.05. Further regression analysis revealed that the simple line regression modal is fit for turbidity and TSS, electrical conductivity and TDS, COD and DO, BOD and DO, and BOD and COD. The studies reveal that Lahore Canal is receiving a considerable amount of physical and chemical pollutants at different points. 相似文献
Lagoons have been traditionally used in India for decentralized treatment of domestic sewage. These are cost effective as they depend mainly on natural processes without any external energy inputs. This study focuses on the treatment efficiency of algae-based sewage treatment plant (STP) of 67.65 million liters per day (MLD) capacity considering the characteristics of domestic wastewater (sewage) and functioning of the treatment plant, while attempting to understand the role of algae in the treatment. STP performance was assessed by diurnal as well as periodic investigations of key water quality parameters and algal biota. STP with a residence time of 14.3 days perform moderately, which is evident from the removal of total chemical oxygen demand (COD) (60 %), filterable COD (50 %), total biochemical oxygen demand (BOD) (82 %), and filterable BOD (70 %) as sewage travels from the inlet to the outlet. Furthermore, nitrogen content showed sharp variations with total Kjeldahl nitrogen (TKN) removal of 36 %; ammonium N (NH4-N) removal efficiency of 18 %, nitrate (NO3-N) removal efficiency of 22 %, and nitrite (NO2-N) removal efficiency of 57.8 %. The predominant algae are euglenoides (in facultative lagoons) and chlorophycean members (maturation ponds). The drastic decrease of particulates and suspended matter highlights heterotrophy of euglenoides in removing particulates. 相似文献
When a domestic wastewater treatment plant (DWWTP) is put into operation, variations of the wastewater quantity and quality must be predicted using mathematical models to assist in operating the wastewater treatment plant such that the treated effluent will be controlled and meet discharge standards. In this study, three types of gray model (GM) including GM (1, N), GM (1, 1), and rolling GM (1, 1) were used to predict the effluent biochemical oxygen demand (BOD), chemical oxygen demand (COD), and suspended solids (SS) from the DWWTP of conventional activated sludge process. The predicted results were compared with those obtained using backpropagation neural network (BPNN). The simulation results indicated that the minimum mean absolute percentage errors of 43.79%, 16.21%, and 30.11% for BOD, COD, and SS could be achieved. The fitness was higher when using BPNN for prediction of BOD (34.77%), but it required a large quantity of data for constructing model. Contrarily, GM only required a small amount of data (at least four data) and the prediction results were analogous to those of BPNN, even lower than that of BPNN when predicting COD (16.21%) and SS (30.11%). According to the prediction, results suggested that GM could predict the domestic effluent variation when its effluent data were insufficient. 相似文献
Environmental monitoring of leachate quality from an open municipal solid waste dumping site in Tunceli, Turkey was studied in this research. The most commonly examined pollution parameters were determined on a seasonal basis. The annual average 5-day biological oxygen demand (BOD5) and chemical oxygen demand (COD) values of station points were measured as 70 and 425 mg/L, respectively, and also the average BOD5/COD ratio (a measure of biodegradability) was calculated as 0.20. The low ratio of biodegradability and slightly alkaline pH values in the leachate samples indicated that the site was characterized by methanogenic conditions. The mean ammonium-nitrogen (NH4+-N) and corresponding phosphate (orthophosphate) values were assayed as 70 and 11 mg/L, respectively. The average solids content in the leachates was measured as 4,681 mg/L (total solids) and 144 mg/L (suspended solids). Very low concentrations of iron, manganese, copper, and zinc in the leachate samples were found and the concentration of cadmium was measured below detection limits. Excessive amount of nutrients and high organic and inorganic pollutant content in the leachates pose serious pollution potential to the environment. Since no drainage system or bio treatment exists in this open dumping site, high permeability of natural soil at the site and in the surrounding area and very fractured and crackled rocks under natural soil are indicators of high groundwater pollution potential in this site. 相似文献
The paper presents new studies about the removal efficiencies and characterization of the Municipal Wastewater Treatment Plant (MWWTP) in Kayseri, Turkey, which is serving for 800,000 population equivalents with the capacity of 110,000 m(3)/day, between 2006 and 2009. Kayseri discharges its effluents to Karasu Creek that downstream joins the Kizilirmak river, the longest river in Turkey discharging into the Black Sea. Four years of operation data between 2006 and 2009 calendar years were obtained from KASKI General Directorate. Influent and effluent samples were collected daily and suspended solids (SS), chemical oxygen demand (COD), biochemical oxygen demand in 5 days (BOD(5)), total nitrogen (TN), and total phosphorus (TP) were measured, aiming to study the evolution of the removal efficiencies for each year. The following yearly mean removal efficiencies were performed in the treatment plant: 94%, 97%, 97%, 95% for SS; 94%, 96%, 95%, 95% for COD; 98%, 98%, 98%, 98% for BOD(5); 84%, 87%, 89%, 82% for TN; and 71%, 86%, 80%, 86% for TP, in 2006, 2007, 2008, and 2009, respectively. The performance of Kayseri MWWTP was given both in terms of influent and effluent quality and in comparison with the current legislation on discharge limits to the receiving body. During the studied period, mean concentrations in the effluent did not exceed the imposed limits, but sometimes, higher values were noticed for SS, TN, and TP. In conclusion, the plant performances concerning these parameters were excellent and Kayseri MWWTP was operating efficiently according to the conventional control parameters. 相似文献
In order to promote pollutant monitoring and preservation of water resources, we evaluate the spatiotemporal trends in recent water quality conditions in Japanese rivers. Trend analysis is conducted on the 92 major rivers in Japan using the available water quality data recorded from 1992 to 2005 and the characteristics of major pollutants in these rivers are analyzed. Spatial and temporal analysis of trends for six water quality indicators is conducted using the Mann Kendall test, a non-parametric statistical method. The indicators analyzed are biochemical oxygen demand (BOD), chemical oxygen demand (COD), dissolved oxygen (DO), total nitrogen (TN), total phosphorus (TP) and pH. The majority of sampling locations monitoring BOD, COD, TN and TP show trends toward decreasing concentrations over time. Many sampling locations show increasing DO concentrations. Our results show that water quality in Japanese rivers has improved dramatically over the past decade, although there are still problems in some places, most notably in the Hokkaido, Kanto, Kinki and Kyushu regions. The improvements seen in water quality appear to be the result of improved wastewater treatment and other water quality improvement efforts achieved through government initiative. 相似文献
The seasonal effects of untreated and treated municipal sewage on the nutrients-nitrate (NO(3)), phosphate (PO(4)), sulphate (SO(4)), and the biochemical oxygen demand (BOD), chemical oxygen demand (COD) and dissolved oxygen (DO) of the receiving urban canal, the Buckingham canal at Kalpakkam (Tamil Nadu, India) was monitored monthly during pre- monsoon-2005 to post-monsoon-2006. The NO(3), PO(4) and SO(4) contents were higher in the downstream than that of the upstream of the outfall points of treated as well as untreated sewage, of the canal. The NO(3) and PO(4) contents were higher during summer than that of monsoon; however the SO(4) was higher during winter and lower during summer in the canal water. The BOD and COD were lower and DO was higher at the upstream than that of downstream of the canal. The concentrations of BOD and COD were higher during summer season, which decreased during monsoon season, while the DO decreased during the summer season and increased in monsoon season in the canal water. Cluster analysis applied to the six sampling points of the canal, has grouped them based on the water quality similarities. 相似文献
Wastewater reuse can significantly reduce environmental pollution and save the water sources. The study selected Cheng-Ching
Lake water treatment plant in southern Taiwan to discuss the feasibility of wastewater recycling and treatment efficiency
of wastewater treatment units. The treatment units of this plant include wastewater basin, sedimentation basin, sludge thickener
and sludge dewatering facility. In this study, the treatment efficiency of SS and turbidity were 48.35–99.68% and 24.15–99.36%,
respectively, showing the significant removal efficiency of the wastewater process. However, the removal efficiencies of NH3–N, total organic carbon (TOC) and chemical oxygen demand (COD) are limited by wastewater treatment processes. Because NH3–N, TOC and COD of the mixing supernatant and raw water are regulated raw water quality standards, supernatant reuse is feasible
and workable during wastewater processes at this plant. Overall, analytical results indicated that supernatant reuse is feasible. 相似文献
Microorganisms have great potential to control environmental pollution, particularly industrial sources of water pollution. Currently, leather industry is regarded as the most polluting and suffering from negative impacts due to the pollution it adds to the environment. Chromium, one of the hazardous pollutants discharged from tanneries, is highly toxic and carcinogenic in nature. Effective treatment of tannery effluent is a dire need of the era as a part of environmental management. Among all the wastewater treatment technologies, bioremediation is the most effective and environment-friendly tool to manage the water pollution. The present study evaluated the potential of 11 previously isolated bacterial strains, tolerant to high concentrations of salts and Cr for the bioremediation of tannery effluent. Among all the tested strains, Enterobacter sp. HU38, Microbacterium arborescens HU33, and Pantoea stewartii ASI11 were found most effective in reducing biological oxygen demand (BOD), chemical oxygen demand (COD), total dissolved solids (TDS), total suspended solids (TSS), and chromium (Cr) 70, 63, 57, 87, and 54%, respectively, of tannery effluent and proliferated well under highly toxic conditions, at 9 days of incubation. The pollutant removal efficacy of these bacterial strains can be improved by extending the incubation period or by increasing the amount of inoculum. 相似文献
The objective of the study was to treat eutrophic river water using floating beds and to identify ideal plant species for design of floating beds. Four parallel pilot-scale units were established and vegetated with Canna indica (U1), Accords calamus (U2), Cyperus alternifolius (U3), and Vetiveria zizanioides (U4), respectively, to treat eutrophic river water. The floating bed was made of polyethylene foam, and plants were vegetated on it. Results suggest that the floating bed is a viable alternative for treating eutrophic river water, especially for inhibiting algae growth. When the influent chemical oxygen demand (COD) varied from 6.53 to 18.45 mg/L, total nitrogen (TN) from 6.82 to 12.25 mg/L, total phosphorus (TP) from 0.65 to 1.64 mg/L, and Chla from 6.22 to 66.46 g/m3, the removal of COD, TN, TP, and Chla was 15.3 %–38.4 %, 25.4 %–48.4 %, 16.1 %–42.1 %, and 29.9 %–88.1 %, respectively. Ranked by removal performance, U1 was best, followed by U2, U3, and U4. In the floating bed, more than 60 % TN and TP were removed by sedimentation; plant uptake was quantitatively of low importance with an average removal of 20.2 % of TN and 29.4 % of TP removed. The loss of TN (TP) was of the least importance. Compared with the other three, U1 exhibited better dissolved oxygen (DO) gradient distributions, higher DO levels, higher hydraulic efficiency, and a higher percentage of nutrient removal attributable to plant uptake; in addition, plant development and the volume of nutrient storage in the C. indica tissues outperformed the other three species. C. indica thus could be selected when designing floating beds for the Three Gorges Reservoir region of P. R. China. 相似文献
Ozone and a Fe2+/TiO2-based catalyst were examined in the degradation of a synthetic solution of benzene toluene and xylene (BTX) in an advanced oxidation process (AOP). The catalyst beads were made from the slurry waste of aluminum production process, by inserting the TiO2 content and subsequent calcination. The reduction of the BTX concentration load was monitored by the reduction of chemical oxygen demand (COD) and BTX concentration. Different levels were used on factors: pH, time of treatment, initial concentration of BTX, and percentage of TiO2. The process was conducted in a bubble column reactor with the insertion of catalyst beads. A response surface methodology technique (CCD) was used to build a model based on COD reduction results. The model was optimized using the normal-boundary intersection (NBI) algorithm to maximize COD reduction and minimize the variance attributed to the process. Optimization led to COD reductions of 80% in 2 h of experiment. Correlation analysis of coefficient models from experimental data R2adj was 0.9966, showing a good fit of model data. In the optimized conditions, the possible increase of the biodegradability ratio of the BTX solution, through the biochemical oxygen demand (BOD) and COD, was also analyzed. Under pre-treatment conditions, the BOD/COD ratio was 0.13. After the treatment, it increased to 0.56.
The Bothnian Bay, which is the northernmost part of the Gulf of Bothnia in Northern Finland, is affected by effluents discharged from point sources such as the pulp and paper mills of Stora Enso Oyj Veitsiluoto Mill and Oy Metsä-Botnia Ab Kemi Mill at Kemi, and the Kemi municipal sewage plant, as well as the River Kemijoki. In this paper we discuss, how modernisation of the wastewater treatment plant at the mills, and process investments in the Best Available Techniques (BAT) for effluent treatment, have decreased the effluent discharges of biological oxygen demand (BOD), chemical oxygen demand (COD), total phosphorus (Tot-P), total nitrogen (TOT-N), total suspended solids (TSS) and adsorbable organically bound halogens (AOX) from the mills since 1988. One specific aim of the study was to determine the EOX (Extractable Organically Bound Halogens) concentrations in bottom sediment of the Bothnian Bay in order to assess whether the EOX concentrations reflect the reduction in discharges of chlorinated compounds. According to the monitoring program carried out every third year between 1997–2006, the decreasing trend in EOX concentrations in the top 2 cm of the bottom sediment reflect the decrease in organochlorine discharges (AOX) from the mills. In 1997 the EOX concentrations in bottom sediment varied between 3–70 μg of Cl g?1 (dry weight), and in 2006 between 3.3–32 μg of Cl g?1 (dry weight). 相似文献
A method aimed at decreasing the toxicity of heavy metals [namely, Zn(II) and Cr(III)] in real polluted residues by immobilisation has been developed. The residues were processed either with two cement-type stabilisers or lime. The cement-type stabilisers were Portland cement and Depocrete SM/2 at the self-generated pH (ca. 11) which afforded physical as well as chemical potential for the immobilisation of heavy metals. The other stabiliser, lime, reduced organic compounds, thus favouring the decrease of the chemical oxygen demand (COD) and endowing the residue with better mechanical properties for transport. After leaching the stabilised residues using the standard leaching test [Order 13/10/89, Boletín Oficial del Estado (BOE) 270 10/11/89], three ways for establishing the toxicity of the treated residues were used, namely: (1) the ecotoxicity test using Photobacterium phosphoreum (DIN 38 412); (2) determination of the concentration of heavy metals by atomic absorption spectrometry (AAS); (3) determination of the COD or oxygen required for complete chemical oxidation of a water sample. Portland cement (20%) blended with Depocrete SM/2 (3%) acted as an effective stabiliser for residues containing heavy metals as it increased the ecotoxicity index (EC50) by more than five times. Thus the heavy metal concentration in the leaching liquid was lowered to less than 0.1 mg l-1. The addition of 5% of lime afforded a residue easily transportable from the place of treatment to the landfill. The precision of the method was studied in terms of both repeatability and reproducibility. The values found with respect to EC50 and expressed as the relative standard deviation (RSD) were 1.6% and 5.1%, respectively. 相似文献