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1.
The wastewater treatment is carried out in two parallel pond groups: South–9200 m3/d, 1748 kg/d BOD5, preliminary clarifier (1.1 ha, 22000 m3), three ponds (9.8 ha, 88000 m3), naturel aeration; North ?5700 m3/d, 2394 kg/d BOD5, Imhoff tank, three ponds (7.9 ha, 71000 m3), the pond 1 artificially aerated by gyroscopic units. The different loads of 15.9 and 33.7 g/m3 d BOD5 results in rates of removal of 11.2 and 22.5 g/m3d BOD5, resp. Therefore, the efficiency of the naturally aerated system is higher than that of the artificially aerated system. In the aerated system mainly the bacterial growth is promoted, a typical algal state being achieved only slowly, whereas the naturally aerated system gains a summer-time algal maximum in the ponds 2 and 3, which is accompanied already by zooplankton populations. In the dynamics of the biomass development, the higher efficiency of the four-stage, naturally aerated system is especially obvious.  相似文献   

2.
The most important measure is that the freshwater demand of 0.5 m3 per t beet processing is strictly kept to or fallen below, to which a catalogue of measures with ten points is presented. The wastewaters which cannot be used again have to be stored prior to the final purification in order to compensate for quantities and concentrations, aerated storage ponds being successful for small sugar factories as the purification technology. For this, three cases are described as examples: supplementary equipment of two anaerobic ponds with a rod-roll aeration, by which within two months (May to July) the BOD3 is reduced from 1,200 to 11 mg/l. The aeration of a pond of 12.5 ha (370,000 … 500,000 m3) by means of a centrifugal aerator (45 kW) does not lead to completely aerobic conditions: Accumulation up to 350 t BOD5, 200 t organic acids at a reduction of 100 t sulphate, 45 t of which being converted via sulphides by photoautotrophic sulphur bacteria. This combination of anaerobic and aerobic processes is very economical. At aeration with ca. 1 W/m3 in the third case in summer there are achieved wastewater loads which are of a receiving-water quality.  相似文献   

3.
The difficulties arisen in an assimilation pond, as it is called, after 17 years of operation were solved by a stabilization system for the purification of effluents and utilization for fish breeding. It consists of two basins (0.56 and 1.04 ha) and a fish pond (15.58 ha) to which water can flow from a brook by-passing the system. When the stabilization system had worked for 6 years, it was proved that in the case of the average daily intake of milk of 93,846…118,134 litres, effluents flowing out of the dairy plant amounted to 205.28…228.53 m3, on average. The BOD5 of effluents ranged from 201.33 to 261.73 kg/d and the total solids ranged from 95.5 to 139.3 kg/d on average. The average daily outflow from the pond amounted to 394.7…1567.0 m3 of water with 4.1…23.8 kg of BOD5 and with 29.3…112.4 kg of total solids. The average decrease of the main nutrients and extractable substances ranged from 62.8% (Ca2+) to 100% (NO?3). Only the BOD5 value at the end of the growing season in 1984 (8.4…10.3 mg/l) exceeded three times the standards for the admissible pollution of the receiving stream.  相似文献   

4.
Biologically purified wastewater in ten doses of 50 and 400 mm per year was given into sand-filled lysimeters of 1 m2 area and 1 m depth which were vegetated with Lolium perenne (forage rye) and green maize all the year round. The experimental results gained in the course of five summer half-years and four winter half-years were evaluated with respect to the purification efficiency of the soil-plant system. The results demonstrate a high efficiency of the system with mean annual elimination performances of 86 and 40% for BOD5, and COD-Cr, resp., as well as 49, 86 and 52% for N, P and K, resp., at mean concentrations in mg/l for BOD5?1.3, COD-Cr?34.1, N?18.1, P?0.4 and K?9 in the percolating water from a soil depth of 1 m. The lysimeters which had been supplied with wastewater were not treated with mineral fertilizer. Intermingling with 1 kg/m2 straw brings about an increase of the loads of K and P as well as COD-Cr in the percolating water and a reduction of the N-loads, besides an increase in yield. All in all, for four years the performance has been stable without any temporal trend.  相似文献   

5.
Thirteen alicyclic compounds (C5… C7) are examined for their biochemical degradability in a laboratory activating tank and in two respirometers (Warburg, Sapromat). The tests were performed with adapted and nonadapted activated sludge. In addition, the COD was determined by three different methods. With the exception of cycloheptane (BOD < 25% of the BODtheor.), six compounds prove to be easily degradable (BOD > 45% of the BODtheor.) and six compounds prove to be degradable (BOD 45… 25% of the BODtheor.).  相似文献   

6.
Dimethyl Sulfoxide Reduction Method for the Characterization of Biomass Activity in Sludge of an Aerated Lagoon The microbial biomass activity was studied in sludge from a wastewater lagoon (Hatzbachtal) which consisted of 4 aerated ponds and one polishing pond. The lagoon was characterized by low BOD5 loading and high dilution because of water from the surroundings. Sludge samples were taken from 4 sampling sites of each aerated pond and from one site of the polishing pond. The biomass activity in the sludge samples was analysed with the help of dimethyl sulfoxide reductase (DRA) and dehydrogenase (DHA) activity. In addition, Corg-content was also determined. The effect of different reaction parameters on the DRA was studied in relation to incubation period, temperature and atmosphere as well as sludge weight and pH value. The results presented here show that a linear increase in the DRA occured for the sludge weight ranging from 0.1 to 0.5 g, incubation period from 0.5 to 11 h and incubation temperature from 20 to 50 °C. The pH spectrum from acidic to neutral did not effect the DMS formation in sludge. Although the values for DRA were always higher in anaerobic incubation of sludge than in aerobic incubation, the courses of the DRA in both conditions were parallel. Comparing the biomass activity in sludge from different sampling sites of the aerated ponds, the average Corg-content was found to be reflected by the DRA and DHA. Further, the variation in the DRA could represent also the influence of oxygen concentration. Therefore, a reduction in biomass activities indicated a decline in the availability of oxygen.  相似文献   

7.
Abstract

Mathematical transformation models of TDS (total dissolved salts) and organic substance concentration as BOD5 (biochemical oxygen demand) in water of the Angara River and the proposed Boguchan Reservoir have been developed. Having filled the reservoir to a water level of 208 m, in an average year it is shown that increase in surface water mineralization is expected in the cross-section of Boguchan Hydroelectric Power Station giving TDS of up to 20–40 mg/dm3, and values of BOD5 will increase to 2.0–3.9 mgO2/dm3. In a low-water year the value of BOD5 may be as great as 5 mgO2/dm3; mineralization, in contrast, decreases. Several years after reservoir filling, the values of BOD5 would decrease, but water quality of the upper part of the reservoir would still depend on the degree of treatment of wastewater discharged to it.

Editor D. Koutsoyiannis

Citation Savichev, O.G. and Matveenko, I.A., 2013. Evaluation of chemical composition changes of surface water in Boguchan Reservoir (Siberia, Russia). Hydrological Sciences Journal, 58 (3), 706–715.  相似文献   

8.
Reduction of the Concentration of Bacteria and Coliphages along the Flowing Stretch of a Treated Sewage Channel The efficiency of surface waters to eliminate E. coli, fecal streptococci, Salmonella spp., and coliphages was evaluated in a small river which receives treated wastewater and which is rich in submerged macrophytes. The study took place between April and December, 1994. Total colony count, BOD5, O2 concentration and water temperature were determined in the river as well. As the river does not receive additional water downwards along its 17.2 km course, dilution effects could be ruled out as the cause for the elimination of the microorganisms. The reduction is assumed to happen rather due to sedimentation, grazing, and adsorption to the submerged waterplants. Immediately after discharge of the wastewater, the river water contained about 105 cfu/100 mL E. coli and 104 cfu/100 mL fecal streptococci, about 1000 pfu/100 mL coliphages, and, as a rule, was positive for salmonella in 10 mL. The reduction of E. coli, fecal streptococci, salmonella, clostridia, and coliphages at the end of the course was 1 to 2 orders of magnitude. This reduction took place mainly within the first 4.7 km, a part in which, due to low flowing velocities, suspended solids settle down efficiently. Besides, at the end of this part the submerged waterplants are especially abundant. The reduction of suspended solids correlated positively with that of BOD5, bacteria, and coliphages. The reduction of microorganisms was not sufficient to fulfill the requirements of the European Community guidelines for bathing waters and for surface waters used as drinking water source. The regenerating capacity of surface waters is not sufficient to eliminate pathogens from convenionally treated wastewater. Therefore, tertiary treatment is necessary to keep receiving waters reasonably free from pathogens.  相似文献   

9.
The water quality of an urban pond in the thickly populated area of Varanasi city (5 km apart) was studied and compared with a rural pond in the Banaras Hindu University campus for transparency, conductivity and nutrient richness (Cl?, SO, PO? P, NO? N, organic carbon, Ca2+, Mg2+, K+, Na+) at three depths (surface, 1.5 m, 3 m) at monthly intervals between February 1982 and February 1983. This was done to assess the effects of urban surroundings of a very ancient city sector on pond water quality in reference to that of a rural pond. The rural pond had a lush growth of 12 macrophytic species, whereas the urban one had only such a growth with many phytoplanktonic species. Transparency was maximum in the winter season and the rural pond water was more transparent, while the electrolytical conductance was maximum in the rainy season, being higher in the urban pond. Electrolytical conductivity was negatively correlated to transparency: urban: EC = 1081.612–6.575 T, r2 = 0.897, F1,11 = 96, P <0.005; rural: EC = 728.981–4.328 T, r2 = 0.892, F1,11 = 91, P <0.005. Chloride and sulphate concentrations were highest in summer months, but the former was much higher in the urban pond while the latter in the rural pond. NO3–N was highest in the rainy season in the rural pond and in early winter in the urban one and showed a definite trend with change in depth. PO4–P also varied with depth and time and it was higher in late summer and the early rainy season in the rural pond and in early winter in the urban pond. But both these nutrients were much higher in the urban pond. The maximum organic carbon concentration was found in the rainy season in the rural pond and in summer months in the urban pond. The variation of organic carbon with depth was distinct. Both summer and winter seasons showed almost similar values of calcium concentration in the rural pond, but in the urban pond it was maximum in summer. Organic carbon and calcium were higher in the urban pond. The magnesium concentration was highest in rainy months in both the ponds, but the periodicity of the minimum differed. The distribution of calcium with depth was not well defined. The highest concentration of potassium was found in the winter season in both the ponds. The sodium concentration in the rural pond was observed maximum in summer and minimum in the rainy season, but in the urban pond the trend was different. The variation of potassium and sodium with depth was not well defined. Magnesium and sodium were also higher in the urban pond but potassium was almost at the same concentration in both the ponds. The effect of urbanisation may be one of the factors which might be responsible to the shift of the species composition towards phytoplanktonic flora.  相似文献   

10.
Lake Gucheng is located in the southeast of Nanjing, with an area of 24.3 km2, an average depth of 2 meters. The macrophytes of the lake were used to be abundant and their biomass was about 4.96 mg·m-2. The annual average contents of total phosphorus (TP), total nitrogen (TN), PO3- -P, CODMn and BOD5 0.03, 1.31, 0.005, 3.61 and 1.46 mg·L-1, respectively. Thus, the water quality of this lake is quite well. Recently, the water quality in pari of the lake became worse because of some unreasonable exploitation and utilization of bioresources. The interactions between phytoplankton (N1), macrophyte (N2), fish (N3), crab (N4) were studied here. The macrophyte has great influences on both phytoplanktons, fish and crab, controlling the water quality and maintaining the fishery productivity. On the other hand, the phytoplankton, fish and crab also influence the macrophyte. It is key method of ecological management to maintain the macrophyte by fishery culture. Therefore, a modified Lotka-Volterra model has been established to estimate the interaction between N1, N2, N3, N4 and the influences of some water environmental parameters on these aquatic organism, environmental and economic effect. The main model consists four compart-mental models and four submodels, involved 12 external variables, 8 state variables, 19 universal constants and 11 parameters. The values of most parameters were found from our experiments and calibrated by the model and actually measured data. The model has been validated by comparison the computed and experimental data of phytoplankton and macrophyte. The theoretical outputs showed a good agreement with the measured data. This model predicated that if the standing crop offish and crab was higher than 2.65 ·m-2 during springtime in this lake, macrophytes would not grow, chlorophyll a content would arrive 34.8 mg·m-3 and the water quality would decrease. If the macrophyte grow well, the maximum fishery productivity would be about 1 600 t. In this case, the annually averaged phytoplankton chlorophyll a content should be 3.69 mg·m-3, which is lower than the criterion (10 mg·m-3) for eutrophic state. From 1991 to 1996, Lake Gucheng was managed with this model, its water quality maintain quite well, chlorophyll a content decreased from 3.51 (1991) to 1.89 mg·m-3 (1994). Meanwhile, the fishery productivity increased and the economic effect heightened year by year.  相似文献   

11.
In this study, a new strain of microorganism Shewanella putrefaciens was used for biofiltration of a pyridine laden air stream in a corn‐cob packed biotrickling filter. In the biotrickling filter tested with S. putrefaciens, the maximum removal of pyridine is determined to be 100% at less than the average inlet concentration of 0.653 g m–3 and more than 93% at a higher average inlet concentration of 1.748 g m–3 (phase VIII) with an empty bed residence time (EBRT) of 106 s. However, when the biotrickling filter was operated at a low EBRT of 53 s and almost the same average inlet concentration of 1.752 g m–3 (phase VII), the removal level attained was not greater than 85%. The maximum elimination capacity (EC) of the biotrickling filter was 102.34 g m–3h–1 at an inlet pyridine load of 119.62 g m–3h–1 with an EBRT of 53 s in phase VII. The maximum deviation of the EC from the 100% conversion line varied from 0.257 to 10.166% when going from phase I to VIII. Kinetic analysis showed that the maximum removal rate, rmax, and saturation constant, Ks, values for pyridine were calculated as 0.24 g m–3h–1 and 6.44 g m–3, respectively, with a correlation coefficient, R2, of 0.9939 and a standard deviation of error of 23.94%. The information contained herein indicates that the corn‐cob packed biotrickling filter inoculated by S. putrefaciens should provide excellent performance in the removal of gaseous pyridine.  相似文献   

12.
内陆水体是大气CO2收支估算的重要组成部分。农业流域分布着大量池塘景观水体,且具备蓄洪抗旱、消纳污染、水产养殖等多种功能。但是,农业流域不同功能的小型池塘CO2排放特征尚不清楚。本研究以极具农业流域代表性的烔炀河流域为研究对象,选取流域中用于水产养殖(养殖塘)、生活污水承纳(村塘)、农业灌溉(农塘)、蓄水(水塘)的4个功能不同的景观池塘,基于为期1年的野外实地观测,以明确农业流域小型池塘CO2排放特征。结果表明,不同功能池塘水体CO2排放差异显著,受养殖活动、生活污水输入和农田灌溉等人类活动影响,养殖塘((80.37±100.39) mmol/(m2·d))、村塘((48.69±65.89) mmol/(m2·d))和农塘((13.50±15.81) mmol/(m2·d))是大气CO2的热点排放源,其CO2排放通量分别是自然蓄水塘((4.52±23.26) mmol/(m2·d))的18、11和3倍。统计分析也表明,该流域池塘CO2排放变化总体上受溶解氧、营养盐等因素驱动。4个不同景观池塘CO2排放通量全年均值为(37.31±67.47) mmol/(m2·d),是不容忽视的CO2排放源,其中养殖塘和村塘具有较高的CO2排放潜力,在未来研究中需要重点关注。  相似文献   

13.
Abstract

A dry pond is an urban drainage component designed to temporarily store stormwater runoff and to encourage infiltration of surface water to the subsurface layer. This paper investigates field measurement of a dry pond at Taiping Health Clinic, Perak, Malaysia that has been functioning well for five years. The pond has a surface area of 195 m2, maximum depth of 32 cm, and a storage capacity of 31.88 m3. The study focused on the infiltration functionality of the constructed dry pond and the results show that it has an average infiltration rate of 125 mm/h and dries up in 330 min after being filled to a depth of 31 mm. A public-domain hydrological model was then employed to simulate hydrographs of ponding and draining, the results of which matched observations with 86–98% accuracy. These results can lead to better understanding of the system and allow duplication of such a drainage design elsewhere.

Editor D. Koutsoyiannis

Citation Lai, S.H. and Mah, D.Y.S., 2012. Field investigation of a dry detention pond with underground detention storage. Hydrological Sciences Journal, 57 (6), 1249–1255.  相似文献   

14.
This study investigated the effectiveness of a new packing material, namely mixed rice husk silica with dried activated sludge for removing H2S. Dried sewage sludge was collected from Putrajaya sewage treatment plant in Malaysia. Rice husk silica was prepared at temperature of 800°C, after acid leaching and mixed with dried sewage sludge to be utilized in a polyvinyl chloride filter. The system was operated under variable conditions of two parameters, different inlet gas concentration and different inlet flow rate. H2S was passed through the filter with one liter of the packing material. More than 99.96% removal efficiency (RE) with empty bed residence time (EBRT) of 90–45 s and 300 ppm inlet concentration was observed. However, the RE decreased to 96.87% with the EBRT of 30 s. The maximum elimination capacity (EC) of 52.32 g/m3/h was obtained with the RE of 96.87% and H2S mass loading rate of 54 g/m3/h, while at the RE of 99.96%, maximum EC was 26.99 g/m3/h with the H2S mass‐loading rate of 27 g/m3/h. A strong significant correlation between increasing of H2S mass loading rate and pressure drop was also detected (p < 0.01). Maximum pressure drop was 3.0 mm H2O after 53 days of operating time, the EBRT of 30 s, and 54 g/m3/h of H2S loading rate. These observations suggest that the mixture of rice husk silica with dried activated sludge is a suitable physico‐biological filter for H2S removal.  相似文献   

15.
There are investigated the variables O2, BOD5, seston, NO3-N, NH4-N and o-PO4 from at least five-year series of five stations along a river section of 50 km. After exclusion of a linear trend and substraction of the individual monthly mean values from the monthly mean of many years in order to eliminate the effect of the annual variation as well as testing for normal distribution, first the correlation coefficients of the variables to the flow rate Q and the temperatures of air and water are determined, which show directional changes just in the longitudinal profile of the river. The same holds for the correlation of the variables between the measuring points. From this the model structure is derived, according to which the concentration at one measuring station can be simulated by multiple regression to Q and T at the same level as well as the concentration at the upper level. The results are discussed in detail and evaluated with respect to their inclusion in longterm management models of water quantity management.  相似文献   

16.
To evaluate the performance of Spirodela polyrrhiza grown in swine wastewater for protein and starch production under field conditions, a pilot‐scale duckweed culture pond was installed at Barham Farm, Zebulon, North Carolina and operated from May to November 2010. The anaerobically treated swine wastewater was fed to the duckweed pond intermittently to provide nutrients for the growth of duckweed, and the duckweed biomass was harvested regularly from the pond and prepared as a protein‐ or starch‐rich feedstock for the production of animal feed or fuel ethanol. Over the experimental period, the duckweed pond produced protein and starch at rates of 2.68 and 1.88 g m?2 day?1, respectively. During the same time, NH4–N and o‐PO4–P in the wastewater were, respectively, removed at rates of 92.9 and 2.90 mmol m?2 day?1.  相似文献   

17.
The plankton collected from three fish ponds shows a considerable variability within a pond, between the ponds and in the course of the year. The individual volumes or weights are (minimum—mean—maximum): Gleotrichia echinulata 41–252–879 μg3, Chlorella vulgaris 18–42–94 μm3, Oscillatoria amphigranulata 99–306–827 μm3, Brachionus plicatilis 1–4.918 μg, nauplia 0.5–1.25–2.35 μg, Mesocyclops hyalinus 4–45–369—μg, Heliodiaptomus viduus 41–202–288 μg, Daphnia carinata 186–1468–4578 μg.  相似文献   

18.
Calcium hydroxide (Ca(OH)2), or hydrated lime, has recently been reintroduced in western Canada as a treatment to reduce macrophytes and algae in eutrophic waters. We examined the effects and recovery of aquatic invertebrates of the Ca(OH)2 treatment (250 mg L–1) of one half of a divided eutrophic pond compared to the untreated half. Nine weeks following treatment, total invertebrates on the untreated side were present at 1917 ± 555 individuals m–2, and on the treated side at 822 ± 186 individuals m–2. Notably, Chironomidae represented 13% of invertebrates on the untreated half, but dominated numerically with 72% on the treated half of the pond. The remaining five most abundant taxa in the untreated side were 88%–99% less abundant in the treated half of the pond. Diversity and evenness were twice as high for the untreated half as for the treated half of the pond. Because macrophytes were also extirpated with the Ca(OH)2 treatment, macrophyteassociated taxa were absent or at low numbers in the treated half. The death of organisms on the treated side of the pond may have been caused (directly or indirectly) by the pH shock associated with Ca(OH)2 treatments. Slow recolonization by most invertebrates during the year of treatment was probably due to the lack of heterogeneous macrophyte habitat. Follow-up sampling 3 years later indicated that the pond completely regained the abundance and biological diversity of flora and fauna.  相似文献   

19.
Chlorophyll pigments (CHL), primary productivity (PP) and particulate nitrogen (Np) in relation to several environmental factors were monitored during planktonic colonization of an aquaculture pond (Layo, Côte d'Ivoire). How interactions between the organisms are established in an initially azoic environment were investigated. From March, 15 (D1) to March, 31 (D16), the system transformation went through three stages. First, a precolonization by heterotrophic microbial community from D1 to D2 (Np < 1 m maximum at D2: 243 mg m–2; CHL around 0). Then, a pioneer microalgal community developped from D3 to D7 (maximum CHL on D6: 19 mg m–2; PP: 1.0 g C m–2 d–1) with a significant contribution of picoplankton (CHL and PP < 3 m: 33 and 23% of the total, respectively). Finally, a second microalgal colonization was noticed from D9 to D12 (maximum CHL: 55 mg m–2, PP: 2.8 g C m–2 d–1), largely dominated by nanoplankton (CHL and PP > 3 m: 95 and 99% of the total, respectively). Overall, photosynthetic activity appeared to be closely linked to algal biomass. The study of autotrophic biomass and activity in different size classes in relation to the other parameters allowed us to precise the origin of the biomass fluctuations. The first bloom appeared to be controlled by selective grazing on small algae. The second algal development ended when N requirement represented at least 69% of N supply (in the N — NH4 form). This control was enhanced by the appearance of rotifers, leading to a more complex equilibrium.  相似文献   

20.
The effluent from biological treatment plants of cane sugar factories undergoes a final purification in laboratory models with a Chlorella culture at volume loads of 76… 325 mg/l. d BOD5 or 121… 555 mg/l-d COD. The coefficient of removal on the basis of BOD5 is found to be linearly negatively correlated with the retention time, but independent of the substrate concentration and composition as well as of the pre-treatment of the wastewaters (aerobic or anaerobic). A dimensioning on the basis of the COD is not possible because of the high phytoplankton content in the effluent of the ponds.  相似文献   

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