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1.
Pollution of rivers caused by human activity is a widely discussed problem, however there is not much attention paid to the changes of water quality that result from the inflow of effluent discharged from fish breeding ponds. The paper presents results of studies on changes of the abiotic parameters (hydrochemical and hydrological) of water observed in the yearly cycle between 2004 and 2008 in selected rivers of Northwest Poland. It was proved that the fastest reaction on the inflow of the effluent discharged from the fish ponds was reflected in changes of biogenic and organic compounds in the river water. The largest, i.e. threefold (rivers Krapiel and Tywa) or even fourfold (rivers Rurzyca and Stepnica) increase in nutrients and organic matter was recorded during the pond effluent discharge into the rivers. At that time values of the organic matter ranged from 8.9 to 18.3 mgO2/dm3 (BOD5), the nitrogen compounds from 16.868 to 26.930 mgN/dm3, while the phosphorus from 1.928 to 6.353 mgP/dm3. Interestingly, an additional dry mass of seston was recorded no earlier than the activity of the harmful element had been stopped and the river had resumed to the “initial” state (i.e. before the effluent discharge); that period varied from one to two months, depending on the river characteristics. The highest values of the dry seston mass (580.9 mg/dm3) was recorded in river Krapiel in November 2006. It seems that in spite of remarkable influence on values of individual physical and chemical indices of the river water quality, the effluent discharge from the fish ponds is not a factor hampering the self-purification processes of the rivers.  相似文献   

2.
Effluent from the manufacture of acrylonitrile is difficult to biodegrade. It contains nine major organic components: acetic acid, acrylonitrile, acrylamide, acrylic acid, acrolein, cyanopyridine, fumaronitrile, succinonitrile, and maleimide. A range of bacteria have been isolated that can grow on, or convert all of the organic components of effluent from the manufacture of acrylonitrile. These bacteria can be used as the basis of a mixed culture system to treat the effluent. The bacteria were utilised in batch and continuous cultures to degrade a synthetic wastewater containing acrylonitrile, acrylamide, acrylic acid, cyanopyridine and succinonitrile. The mixed microbial population was adapted by varying the growth rate and switching from continuous to batch and back to continuous growth, to degrade these five compounds as well as acrolein, fumaronitrile and maleimide.Abbreviations BOD Biological Oxygen Demand - COD Chemical Oxygen Demand - T D Doubling Time - ppm parts per million - HPLC High Pressure Liquid Chromatography - GLC Gas Liquid Chromatography  相似文献   

3.
Sea-surface microlayer and underlaying water samples were collected in the Bay of Marseilles (France) in order to study respiratory activity of microneuston and its possible influence on respiratory CO2 production. Three methods were tested: Biochemical Oxygen Demand (BOD) as an estimation of community respiration, Electron Transport System activity (ETS) and 14C-Glucose uptake monitored by 14C-CO2 liberation. BOD and ETS data clearly showed enhanced respiratory activities (up to 310 μl O2/l/h) in surface-films as compared to underlaying waters; moreover the slope of the linear regression between these data led to R/ETS value of 0.689 and provides evidence for the presence of an important heterotrophic fraction within the microneuston. Though 14C-Glucose measurements showed only a slight trend for higher total activity (incorporation + respiration) in surface microlayers, significant enhancement of relative 14C-CO2 production giving rise to CO2 diffusion across air-water interface was observed.  相似文献   

4.
In this study, water hyacinth (Eichhornia crassipes) was used to treat domestic wastewater. Ten organic and inorganic parameters were monitored in three weeks for water purification. The six chemical, biological and physical parameters included Dissolved Oxygen (DO), Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Ammoniacal Nitrogen (NH3-N), Total Suspended Solids (TSS), and pH were compared with the Interim National Water Quality Standards, Malaysia River classification (INWQS) and Water Quality Index (WQI). Between 38% to 96% of reduction was observed and water quality has been improved from class III and IV to class II. Analyses for Electricity Conductivity (EC), Salinity, Total Dissolved Solids (TDS) and Ammonium (NH4) were also investigated. In all parameters, removal efficiency was in range of 13–17th day (optimum 14th day) which was higher than 3 weeks except DO. It reveals the optimum growth rate of water hyacinth has great effect on waste water purification efficiency in continuous system and nutrient removal was successfully achieved.  相似文献   

5.
An optical fiber biosensor was developed for the evaluation of low Biochemical Oxygen Demand (BOD) values in river waters. Artificial wastewater (AWW) solution was employed as standards for the calibration of the BOD sensor. The response time of the sensor was 15 min, and the optimal BOD response was observed at 30 degrees C, pH 7.0. A linear relationship was obtained between the output voltage and BOD5 values, and the range of determination was 1-10 mg l(-1) BOD. The sensor response was almost not influenced by chloride ion up to 1000 mg l(-1), and also not affected by heavy metal ions (Fe3+, Cu2+, Mn2+, Cr3+, Zn2+). The BOD of river waters was estimated by using the optical fiber biosensor, and good correlation between the sensor and BOD5 test was obtained (r2 = 0.971).  相似文献   

6.
The literature concerning methane (CH4) emissions from temperate and boreal lakes is extensive, but emissions from tropical and subtropical lakes have been less documented. In particular, methane emissions from Mexican lakes, which are often polluted by anthropogenic carbon and nutrient inputs, have not been reported previously. In this work, methane emissions from six Mexican lakes were measured, covering a broad range of organic inputs, trophic states, and climatic conditions. Methane emissions ranged from 5 to 5,000 mg CH4 m?2 day?1. Water samples from several depths in each lake were analyzed for correlation between water quality indicators and methane emissions. Trophic state and water quality indexes were most strongly correlated with methane fluxes. The global methane flux from Mexican freshwater lakes was estimated to be approximately 1.3 Tg CH4 year?1, which is about 20% of methane and 4.4% of total national greenhouse gas emissions. Data for untreated wastewater releases to the environment gave an emission factor of 0.19 kg CH4 kg?1 of Biochemical Oxygen Demand, which is superior to that previously estimated by the IPCC for lake discharges. Thus, the large volume of untreated wastewater in Mexico implies higher methane emission than previously estimated.  相似文献   

7.
Li J  Luan Z  Yu L  Ji Z 《Bioresource technology》2011,102(22):10319-10326
A combined Fenton-UASB (2 phase)-SBR system was employed to treat acrylic fiber manufacturing wastewater. The Chemical Oxygen Demand (COD) removal and effluent Biochemical Oxygen Demand (BOD) to COD were 65.5% and 0.529%, respectively, with the optimal Fenton conditions: ferrous was 300 mg/L; hydrogen peroxide was 500 mg/L; pH was 3.0; reaction time was 2.0 h. In two-phase UASB reactor, mesophilic operation (35±0.5 °C) was performed with hydraulic retention time (HRT) varied between 28 and 40 h. The results showed that with the HRT not less than 38 h, COD and sulfate removal were 65% and 75%, respectively. The greatest sizes of granule formed in the sulfate-reducing and methane-producing phases were 5 and 2 mm, respectively. Sulfate-reducing bacteria (SRB) accounted for 35% in the sulfate-reducing phase while methane-producing archaea (MPA) accounted for 72% in the methane-producing phase. During the SBR process, shortcut nitrification was achieved by temperature control of 30 °C.  相似文献   

8.
The initial formation of biofilm and the removal performance of pollutants in biological pretreatment process for polluted raw water were limited due to the oligotrophic niche in raw water. In this study, the feasibility of using pre-inoculation biofilm formed under nutrients enhanced condition for polluted raw water treatment was analyzed in nine batch reactors. Results showed that the pollutants removal performance of biofilm was improved under nutrients enhanced conditions. Ammonia oxidation rate (AOR) was exponentially increased with the increasing in NH4 +-N levels, and organic matter removal rate (ORR) was positively related to the initial total organic carbon (TOC) concentration. The biofilm formation and microbial diversity were further improved via adding more substrates, seeding river sediment and feeding effluent from a mature biofilm reactor. However, the biofilm formed under higher substrate conditions had higher half-saturation constant values (K S) to both NH4 +-N and TOC, which decreased AOR and ORR values when it was used to treat polluted raw water. The reduction percentage of AOR and ORR showed logarithmic growth modes with the increase in K S values. Fortunately, improvement of nutrients flux via accelerating influent replacement could enhance the start-up performance effectively and decrease the operation risk introduced by the changes in substrate affinity.  相似文献   

9.
The role of chlorinated primary effluents in viral pollution of the Ottawa River (Ontario) was assessed by examining 282 field samples of wastewaters from two different sewage treatment plants over a 2-year period. The talc-Celite technique was used for sample concentration, and BS-C-1 cells were employed for virus detection. Viruses were detected in 80% (75/94) of raw sewage, 72% (68/94) of primary effluent, and 56% (53/94) of chlorinated effluent samples. Both raw sewage and primary effluent samples contained about 100 viral infective units (VIU) per 100 ml. Chlorination produced a 10- to 50-fold reduction in VIU and gave nearly 2.7 VIU/100 ml of chlorinated primary effluent. With a combined daily chlorinated primary effluent output of approximately 3.7 × 108 liters, these two plants were discharging 1.0 × 1010 VIU per day. Because the river has a mean annual flow of 8.0 × 1010 liters per day, these two sources alone produced a virus loading of 1.0 VIU/8 liters of the river water. This river also receives at least 9.0 × 107 liters of raw sewage per day and undetermined but substantial amounts of storm waters and agricultural wastes. It is used for recreation and acts as a source of potable water for some 6.0 × 105 people. In view of the potential of water for disease transmission, discharge of such wastes into the water environment needs to be minimized.  相似文献   

10.
To determine whether existing dissolved oxygen (DO) regulationswere adequate to protect riverine biota, the Northern River Basins Studyrequired a research and assessment program to establish the effect ofpulp mill and municipal sewage discharges on under-ice DO concentrationsand aquatic biota in the Athabasca, Wapiti and Smoky rivers of northernAlberta, Canada. Analysis of monitoring data collected over >30 yearsshowed that pulp mill and municipal effluents have caused sags in DObelow their discharges and contributed to an increased rate of declinein DO over 10s of kilometers in the Wapiti-Smoky rivers or 100s ofkilometers in the Athabasca River. To permit forecasting of DO declinesin response to changes in river discharge or effluent biochemical oxygendemand (BOD), a one-dimensional steady-state river water quality modelwas implemented that successfully (r2 =0.74–0.92) predicted DO concentrations over an 820 km reach of theAthabasca River for the 1990–1994 winters. Experiments on nativefish and benthic macroinvertebrate species showed that exposure to lowDO and low temperatures (2–3°C) caused delays in hatch ofmountain whitefish eggs (at 6.5 mg/L DO), reduced mass of bull troutalevins post-hatch (at 5.0 mg/L DO), extended the spawning period ofburbot (at 6.0 mg/L DO), and depressed feeding rates and loweredsurvival of the mayfly Baetis tricaudatus (at 5 mg/L DO).As a result of recommendations from this integrated program of rivermonitoring, modelling and experimentation, effluent BOD loading has beenreduced to the Athabasca and Wapiti rivers and the provincial DOguideline for protection of aquatic life has been increased from 5.0 to6.5 mg/L.  相似文献   

11.

In wetland ecosystem, nitrogen along with other elements and its management is most imperative for the production of so many aquatic food, non-food and beneficial medicinal plants and for the improvement of soil and water characteristics. With great significant importance of INM (integrated nutrient management) as sources, emphasizing on management on nitrogen as a key element and its divergence, a case study was undertaken on such aquatic food crops (starch and protein-rich, most popular and remunerative) in the farmers’ field of low-lying ‘Tal’ situation of New Alluvial Zone of Indian subtropics. The study was designed in factorial randomized block design, where, three important aquatic food crops (water chestnut (Trapa bispinosa Roxb.), makhana (Euryale ferox Salisb.) and water lily (Nymphaea spp.) as major factor and eleven combinations of organic and inorganic sources of nutrients as sub-factor was considered in the experiment. It revealed from the results that the production of fresh kernels or nuts of water chestnut (8.57 t ha−1), matured nut yield of makhana (3.06t ha−1) and flower stalks of water-lily as vegetables (6.38 t ha−1) including its nutritional quality (starch, protein, sugar and minerals) was remarkably influenced with the application of both organic (neem oilcake @ 0.2 t ha−1) and inorganic sources (NPK @ 30:20:20 kg ha−1 along with spraying of NPK @ 0.5% each over crop canopy at 20 days interval after transplanting) than the other INM combinations applied to the crops. Among the crops, highest WCYE (water chestnut yield equivalence) exhibited in makhana due to its high price of popped-form in the country, which is being exported to other countries at now. Sole application of both (organic and inorganic sources) with lower range did not produce any significant outcome from the study and exhibited lower value for all the crops. Besides production of food crops, INM also greatly influenced the soil and water characterization and it was favourably reflected in this study. The physico-chemical characteristics of soil (textural class, pH, organic carbon, organic matter, ammoniacal nitrogen, nitrate nitrogen, available nitrogen, phosphorus and potassium) are most important and contributed a significant improvement due to cultivation of these aquatic crops. Analysis of such wet bodies represented the water characteristics (pH, BOD, COD, CO =3 , HCO 3 , NO 3 N, SO 4 S and Cl) were most responsive, adaptable and quite favourable for the cultivation of these crops in this vast waste unused wetlands for the mankind without any environmental degradation.

  相似文献   

12.
1. Aerobic respiration, productivity and the carbon turnover rate of microbial biofilms were determined at hyporheic and phreatic sites in the Kalispell Valley alluvial aquifer along a transect extending 3.9 km laterally from the main channel of the Flathead River, a sixth order river in Montana (U.S.A.). The effect of experimentally increasing bioavailable organic carbon (acetate) on the respiration rate of biofilms in this carbon‐poor [dissolved organic carbon (DOC) < 2 mg L?1] aquifer was also measured. 2. Chambers containing natural substratum were placed in‐situ and allowed to colonise for 20 weeks. After 4, 12 and 20 weeks, they were taken to the laboratory where oxygen flux was measured in a computer‐controlled, flow‐through respirometry system. 3. Respiration ranged from 0.01 to 0.33 mg O2 dm?3 h?1 across sites, with means ranging from 0.10 to 0.17 mg O2 dm?3 h?1. Productivity estimates ranged from 0.18 to 0.32 mg C dm?3 day?1 (mean 0.25, SE 0.03). The total organic carbon (TOC) of the microbial biofilms ranged from 18.2 to 29.7 mg C dm?3. Turnover rate ranged from 3.2 to 5.6 year?1 with a mean of 4.2 year?1. 4. At the hyporheic site very close to the river, respiration did not significantly increase when samples were supplemented with labile carbon. Respiration increased with increasing DOC addition at hyporheic sites more distant from the river, suggesting a carbon‐limitation gradient within the hyporheic zone. Microbes at the phreatic site did not respond to increasing DOC addition, suggesting that the phreatic biofilm is adapted to low carbon availability. 5. Comparing the volume of the alluvial aquifer (about 0.7 km3) to that of the river benthic sediments (to 0.25 m depth, which amounts to about 1.6 × 10?4 km3) within the Flathead Valley, leads to the conclusion that interstitial microbial productivity is orders of magnitude greater than benthic productivity. Alluvial aquifers are often voluminous and microbial production is an enormous component of ecosystem production in rivers such as the Flathead.  相似文献   

13.
A 3-year study was conducted on an existing, one-cell, facultative sewage lagoon having a total surface area of 3.6 ha and receiving a BOD5 loading rate of 44 kglhald (40 Iblald). The comparative experimental periods ran from July through November for 3 consecutive years. During the first period, water hyacinths completely covered the lagoon. The water hyacinth coverage was reduced to 33% of the total surface area the second year. The lagoon, free of all vascular aquatic plants the third year, was monitored for comparative purposes. The most significant improvement overall in the effluent quality occurred when water hyacinths covered the entire lagoon. During this period the effluent BOD5 and TSS were 23 and 6 mgll, respectively. Without water hyacinths, the effluent BOD5 and TSS were 52 and 77 mgll, respectively. The effluent total organic carbon concentration with water hyacinths averaged 40 mgll, and without water hyacinths, 72 mgll. A discussion of the results from this 3-year study is presented in this paper along with associated problems that were observed when water hyacinths were introduced into the lagoon and altered its behavior from that of a normal facultative lagoon.  相似文献   

14.
Wang X  Wen X  Xia Y  Hu M  Zhao F  Ding K 《PloS one》2012,7(4):e36272

Background

Chemoautotrophic ammonia oxidizing bacteria (AOB) have the metabolic ability to oxidize ammonia to nitrite aerobically. This metabolic feature has been widely used, in combination with denitrification, to remove nitrogen from wastewater in wastewater treatment plants (WWTPs). However, the relative influence of specific deterministic environmental factors to AOB community dynamics in WWTP is uncertain. The ecological principles underlying AOB community dynamics and nitrification stability and how they are related are also poorly understood.

Methodology/Principal Findings

The community dynamics of ammonia oxidizing bacteria (AOB) in a pilot-scale WWTP were monitored over a one-year period by Terminal Restriction Fragment Length Polymorphism (T-RFLP). During the study period, the effluent ammonia concentrations were almost below 2 mg/L, except for the first 60 days, indicting stable nitrification. T-RFLP results showed that, during the test period with stable nitrification, the AOB community structures were not stable, and the average change rate (every 15 days) of AOB community structures was 10%±8%. The correlations between T-RFLP profiles and 10 operational and environmental parameters were tested by Canonical Correlation Analysis (CCA) and Mantel test. The results indicated that the dynamics of AOB community correlated most strongly with Dissolved Oxygen (DO), effluent ammonia, effluent Biochemical Oxygen Demand (BOD) and temperature.

Conclusions/Significance

This study suggests that nitrification stability is not necessarily accompanied by a stable AOB community, and provides insight into parameters controlling the AOB community dynamics within bioreactors with stable nitrification.  相似文献   

15.
An anaerobic reactor and a fixed-bed adsorption sequential system (FBAS) were applied to remove color from kraft mill effluent. Under anaerobic conditions, Biological Oxygen Demand (BOD5) removal was between 84 to 90% w/w, while Chemical Oxygen Demand (COD) removal ranged between 46 to 55% w/w. Total phenolic compounds were poorly removed (8 to 15% w/w) whereas the color was not removed by anaerobic digestion. For the FBAS system, three different columns were packed with natural and activated (calcinated and acidified) allophanic soil and fed with kraft mill anaerobic effluent. In activated soil columns, color and total phenolic compounds removal were around 95% w/w, whereas in the natural soil column the values were 87% w/w and 81% w/w, respectively.  相似文献   

16.
Ferric-Carbon Micro-Electrolysis (Fe/C-M/E) material had been widely used for the pretreatment of wastewater. Therefore, we hypothesized that Fe/C-M/E material could enhance the treatment of domestic sewage when it was integrated into constructed wetlands (CWs). In this study, CWs integrated with Fe/C-M/E material were developed. Druing the experiment of effect of vegetation on the performance of CWs, percentages of NH4+-N, NO3?-N, total nitrogen (TN), and Chemical Oxygen Demand (COD) removed in polyculture (W1) were up to 91.8%, 97.0%, 92.3%, and 85.4%, respectively, which were much higher than those in Lythrum salicaria monoculture (W2) and Canna indica monoculture (W3). In the experiment of temperature influences on the removal efficiency of CWs, temperature substantially influenced the performance of CWs. For example, NO3?-N removal percentages of W1, W2, and W3 at high temperature (25.5°C and 19.8°C) were relatively stable and greater than 85.4%. At 8.9°C, however, a sharp decline of NO3?-N removal percentage was observed in all CWs. Temperature also influenced the Chemical Oxygen Demand (COD) removal and soil microbial activity and biomass. Overall, the polyculture (Lythrum salicaria +Canna indica) showed the best performance during most of the operating time, at an average temperature ≥ 19.8°C, due to the functional complementarity between vegetation. All the CWs consistently achieved high removal efficiency (above 96%) for TP in all experiments, irrespective of vegetation types, phosphorous loadings, and temperatures. In conclusion, polyculture was an attractive solution for the treatment of domestic sewage during most of the operating time (average temperature ≥ 19.8°C). Furthermore, CWs with Fe/C-M/E material were ideally suitable for domestic sewage treatment, especially for TP removal.  相似文献   

17.
Two constructed wetlands, one with Azolla pinnata plant (CW1) and the other without (CW2) for treating domestic wastewaters were developed. Fifteen water parameters which include: Dissolved Oxygen (DO), Biochemical Oxygen Demand (BOD5), Chemical Oxygen Demand (COD), Total Suspended Solid (TSS), Total Phosphorus (TP), Total Nitrogen (TN), Ammoniacal Nitrogen (NH3N), Turbidity, pH, Electrical Conductivity (EC), Iron (Fe), Magnesium (Mg), Manganese (Mn), and heavy metals such as Lead (Pb) and Zinc (Zn) were analyzed using standard laboratory procedures. The experiments were conducted in two (dry and wet) seasons simultaneously. Results showed considerable reductions in all parameters and metals including Zn in CW1 compared with CW2 in the two seasons considered while Pb and Mn were not detected throughout the study. Zn concentration levels reduced significantly in both seasons just as removal efficiencies of 70.03% and 64.51% were recorded for CW1 while 35.17% and 33.45% were recorded for CW2 in both seasons. There were no significant differences in the removal efficiencies of Fe in both seasons as 99.55%, 59.09%, 88.89%, and 53.56% were recorded in CW1 and CW2 respectively. Azolla pinnata has proved effective in domestic wastewater phytoremediation studies.  相似文献   

18.
Retting trials carried out in this study have shown that chemical and enzyme retting could be carried out at a semi-industrial scale. The yield from enzyme retted fibres was higher than chemical or water retted flax fibres. The variation in fibre fineness, strength, fluidity and moisture regain was not significantly different, thereby proving that chemicals and enzymes do not degrade or depolymerise the cellulose chains. The activity of the enzymes at the end of retting, when investigated, remained quite high, suggesting that the waste liquor could be recycled after removing the suspended solids present in the liquor. Biochemical oxygen demand (BOD) and chemical oxygen demand (COD) were highest in effluent from enzyme retting compared to effluents from chemical or water retting. All three effluents were analysed for N2, PO4, Cl, SO4, Na and K. Aeration of the effluents reduced the level of BOD and COD by more than 50%.  相似文献   

19.
The water quality of the Lwiro River, Democratic Republic of Congo (DRC), Central Africa, was investigated on a monthly basis from December 1999–October 2000, at six stations along a hydraulic gradient from source to mouth, to evaluate the impact of land use on temperature, Dissolved Oxygen (DO), Biological Oxygen Demand (BOD5), alkalinity and suspended solids. Upstream, where forests are conserved, minimal changes of physico-chemical parameters of water were observed. Downstream, DO was reduced, due to the increased organic matter content which increased the decomposition rate. BOD5 and suspended solids increased downstream. Greater changes were found near agricultural areas and villages. Wetlands appear to mitigate BOD5 and DO impacts.  相似文献   

20.
每年有大量来自工业、农业、养殖业和城市污水处理厂的废水被排入到水环境中,因此,地球上的水环境面临大量来自生活废水、工农业废水、非法排放的废水及其它废水的污染物质(如抗生素、杀虫剂,除草剂、烃等)的严重挑战,特别是近年来随着集约化养殖的发展,废水污染问题日益突出,并且随着分析手段的进步,能够检测到被排入水环境中的化学污染物质也越来越多,这些化学污染物对水环境中的生物产生有害影响.但是,微生物在污染控制上具有许多重要的作用.因此,本文对微生物在水环境污染物降解中的应用进行了评论.结果表明微生物主要是应用在水产养殖水中,而在其它的水体系(如河、湖、海)的应用较少.  相似文献   

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