Particulate phosphorus transport within stream flow of an agricultural catchment

There is interest in quantifying phosphorus (P) loss from intensively grazed dairy landscapes to identify key pathways and target remediation methods. The Bog Burn drains a dairying catchment in Southland, New Zealand, and has been monitored at fortnightly intervals over a 12-mo period at four sites for suspended sediment (SS), dissolved reactive phosphorus (DRP), and total phosphorus (TP). Time-integrated samplers, deployed at 0.6 median water depth at each site (calculated from previous year's flow data), collected sediment samples, which were analyzed for SS, bioavailable phosphorus (BAP), and TP. Mean concentrations of DRP and TP in stream flow and BAP and TP in sediment were generally highest in summer or autumn (0.043 mg DRP L(-1), 0.160 mg TP L(-1), 173 mg BAP kg(-1), 2228 mg TP kg(-1)) and lowest in winter or spring (0.012 mg DRP L(-1), 0.034 mg TP L(-1), 6 mg BAP kg(-1), 711 mg TP kg(-1)), while loads were highest in winter. Analysis of (137)Cs concentrations in trapped sediment, topsoil, subsoil, and stream bed and bank sediment indicated that trapped sediment was derived from topsoil and entered the stream either through tile drainage or, to a lesser extent, overland flow. Because concentrations of DRP and TP in stream flow are in excess of recommended limits for good water quality (>0.01 mg DRP L(-1), 0.033 mg TP L(-1)), management should focus on the topsoil and specifically on decreasing P loss via tile drainage. This is best achieved by decreasing soil Olsen P concentrations, especially because, on average, Olsen P concentrations in the catchment were above the agronomic optimum.     

Anaerobic-aerobic treatment of purified terephthalic acid (PTA) effluent; a techno-economic alternative to two-stage aerobic process

This paper addresses the treatment of purified terephthalic acid (PTA) effluent using anaerobic and aerobic processes. Laboratory studies were carried out on flow proportionate composite wastewater generated from the manufacturing of PTA. An activated sludge process (ASP-two stage and single stage) and an upflow anaerobic fixed film fixed bed reactor (AFFFBR) were used, individually and in combination. The performance of a full-scale ETP under existing operating conditions was also studied. Full scale ETP studies revealed that the treatment of PTA effluent using a two-stage ASP alone does not meet treated effluent quality within the prescribed Indian Standards. The biomass produced in the two stage ASP was very viscous and fluffy and the sludge volume index (SVI) was very high (200-450 ml/g). However, pretreatment of PTA effluent using an upflow AFFFBR ensured substantial reduction in BOD (63%) and COD (62%) with recovery of biogas at 1.8-1.96 l/l effluent treated at a volumetric loading rate (VLR) 4-5 kg COD/m(3) d. The methane content in the biogas varied between 55% and 60%. The pretreated effluent from the upflow AFFFBR was then treated through a single stage ASP. The biomass produced in the ASP after anaerobic treatment had very good settlability (SVI: 75-90 ml/g) as compared to the two stage ASP and the treated effluent quality with respect to BOD, COD and SS was within the prescribed Indian Standards. The alternative treatment process comprising an upflow AFFFBR and a single stage ASP ensured net power saving of 257 kW and in addition generated 442 kW of power through the AFFFBR.     

垂直流人工湿地处理稠油废水的实验研究

采用垂直流人工湿地模拟装置对新疆油田外排含盐稠油废水进行了处理。实验表明:对于进水CODCr为402～406mg/L,盐度5701～5712mg/L,石油类40.62mg/L的含盐稠油废水,该系统的出水指标为CODCr35～38mg/L,盐度1535～1542mg/L,湿地系统对CODCr和盐分的去除率达到91%和73%;当水力停留时间为11d以上,出水石油类<5mg/L,处理后出水CODCr、石油类达到《污水综合排放标准》(GB8978-1996)的一级标准。     

Use of constructed wetland systems with Arundo and Sarcocornia for polishing high salinity tannery wastewater

Treatment of tannery wastewater is problematic due to high and variable concentrations of complex pollutants often combined with high salinity levels. Two series of horizontal subsurface flow constructed wetlands (CWs) planted with Arundo donax and Sarcocornia fruticosa were set up after a conventional biological treatment system operating at a tannery site. The aim of the CWs was polishing organics and nitrogen from the high salinity effluent (2.2-6.6?g Cl(-)?L(-1)). Both plant species established and grew well in the CW. Arundo, however, had more vigorous growth and a higher capacity to take up nutrients. The CWs were efficient in removing COD and BOD(5) with removal efficiencies varying between 51 and 80% for COD (inlet: 68-425?mg?L(-1)) and between 53 and 90% for BOD(5) (inlet: 16-220?mg?L(-1)). Mass removal rates were up to 615?kg COD ha(-1)?d(-1) and 363 BOD(5) kg?ha(-1)?d(-1). Removal efficiencies were 40-93% for total P, 31-89% for NH(4)(+) and 41-90% for Total Kjeldahl Nitrogen. CW systems planted with salt tolerant plant species are a promising solution for polishing saline secondary effluent from the tannery industry to levels fulfilling the discharge standards.     

双滤料曝气生物滤池污水深度处理的研究

采用陶粒、沸石为滤料的曝气生物滤池对生物处理系统二级出水进行深度处理回用,研究了水力停留时间、气水体积比对污染物COD和NH3-N处理效果的影响。结果表明：水力停留时间为8 h,气水体积比为3∶1的工况下,处理效果较好。稳定运行后,出水COD、BOD5、SS、NH3-N、TP和色度平均值分别为15.6 mg/L、3.2 mg/L、8.5 mg/L、1.24 mg/L、0.40mg/L和8度,达到《城市污水再生利用—城市杂用水水质》（GB/T 18920-2002）标准,出水可用于道路清扫、绿化等。     

In situ accumulation of copper, chromium, nickel, and zinc in soils used for long-term waste water reclamation

We studied the long-term in situ accumulation of Cu, Cr, Ni, and Zn in the soil profile of a large-scale effluent recharge basin after 24 yr of operation in a wastewater reclamation plant using the Soil Aquifer System approach in the Coastal Plain of Israel. The objective was to quantify metals accumulation in the basin's soil profile, clarify retention mechanisms, and calculate material balances and metal removal efficiency as the metal loads increase. Effluent recharge led to measurable accumulation, relative to the pristine soil, of Ni and Zn in the 0- to 4-m soil profile, with concentration increases of 0.3 to 1.3 mg kg(-1) and 2.9 to 6.4 mg kg(-1), respectively. Copper accumulated only in the 0- to 1-m top soil layer, with concentration increase of 0.28 to 0.76 mg kg(-1). Chromium concentration increased by 3.1 to 7.3 mg kg(-1) in the 0- to 1-m horizon and 0.9 to 2.3 mg kg(-1) at deeper horizons. Sequential selective extraction showed Cu tended to be preferentially retained by Fe oxides and organic matter (OM), Cr by OM, Ni by OM, and carbonate and Zn by carbonate. The average total retained amounts of Cu, Cr, Ni, and Zn were 0.7 +/- 1.0, 13.6 +/- 4.8, 4.3 +/- 3.6, and 28.7 +/- 5.4 g per a representative unit soil slab (1 m(2) x 4 m) of the basin, respectively. This amounts to 3.6 +/- 4.9%, 79.5 +/- 28.0%, 8.0 +/- 6.9%, and 9.3 +/- 1.8% of the Cu, Cr, Ni, and Zn loads, respectively, applied during 24 yr of effluent recharge (total of approximately 1880 m effluent load). The low long-term overall removal efficiency of the metals from the recharged effluent in the top horizon may be due to the metals' low concentrations in the recharged effluent and the low adsorption affinity and retention capacity of the sandy soil toward them. This leads to attainment of a quasi-equilibrium and a steady state in element distribution between the recharged effluent solution and the soil after few years of recharge and relatively small cumulative effluent loadings.     

Performance of an overland flow system for advanced treatment of wastewater plant effluent

Overland flow (OF) systems were evaluated and compared for advanced treatment of municipal and industrial effluents, including nutrients and nondegradable chemical oxygen demand (COD) removal. Three pilot plants were constructed at the Shahin Shahr Wastewater Treatment Plant (WWTP), Isfahan, Iran. Each pilot was assigned a specific wastewater and all were simultaneously operated for 8 months. Treatment of primary effluent, activated sludge secondary effluent, and lagoon effluent of textile wastewater was investigated at application rates (ARs) of 0.15, 0.25, and 0.35m(3)m(-1)h(-1). During 5 months of stable operation after a 3-month acclimation period, mean removals of total 5-day biochemical oxygen demand (TBOD(5)), total COD (TCOD), total suspended solids (TSS), total nitrogen (TN), total phosphorus (TP) and turbidity were 74.5%, 54.8%, 66.2%, 39.4%, 35.8%, and 67.7% for primary effluent; 52.9%, 52.9%, 66.5%, 44.4%, 39.8%, and 50.1% for activated sludge effluent; 65.7%, 58.7%, 70.3%, 41.7%, 41.3%, and 54.9% for textile wastewater lagoon effluent, respectively. The model of Smith and Schroeder, 1985. Field studies of the overland flow process for the treatment of raw and primary treated municipal wastewater. Journal of Water Pollution Control Federation 57, 785-794] was satisfactory for TBOD(5). For all treatment parameters a standard first-order removal model was inadequate to represent the data but a modified first-order model provided a satisfactory fit to the data. Based on the results of this study, it can be concluded that an OF system as advanced treatment had the ability to meet effluent discharge permit limits and was an economical replacement for stabilization ponds and mechanical treatment options.     

中空纤维膜生物反应器处理炼厂浮选池出水试验研究

研究设计的膜生物反应器处理炼厂浮选池出水,在每天进水容积负荷1.0 kg COD/m3,进水COD浓度600 mg/L,MLSS为900～5500 mg/L的条件下,无论活性污泥表现正常还是膨胀,过滤出水中COD均稳定地小于90 mg/L,处理效果好于目前炼油厂的合建式曝气池(容积负荷为0.5 kg COD/m3左右,出水COD100 mg/L左右)。试验运行期间,膜通量最高可达到42 L/m2·h。该工艺的技术关键是采用特殊流态来降低膜堵塞的膜生物反应器和优良质量的膜。     

臭氧—活性炭技术处理石油微污染地下水*

在实验室及中试条件下研究了臭氧-活性炭技术对石油微污染地下水的处理效果。通过石油类和高锰酸盐指数两个指标,考察了臭氧投加量、pH值、过滤速率等操作参数对污染物的去除效果。结果表明:臭氧投加量和活性炭过滤速率是最主要的影响因素,pH值对处理效果影响不显著。中试条件下适宜的臭氧投加量应为8mg/L左右,最佳过滤速率在10m/h附近。采用臭氧氧化与活性炭过滤组合工艺,当进水石油类浓度在1.5mg/L以下时,出水石油类低于0.3mg/L,高锰酸盐指数低于3.0mg/L。     

聚结除油—气浮—过滤工艺处理稠油污水

在石油开采过程中,油水分离产生大量的稠油污水。稠油污水组成复杂、污染性强,如不经处理直接排放会对环境造成污染危害。针对油田进行污水处理工艺研究,以除油和悬浮物为主。即采用聚结除油—气浮—过滤的处理工艺,处理后的出水SS和含油量为5mg/L,达到回注水控制指标,经回注泵加压回注地层。     

聚结除油-气浮-过滤工艺处理稠油污水

在石油开采过程中,油水分离产生大量的稠油污水.稠油污水组成复杂、污染性强,如不经处理直接排放会对环境造成污染危害.针对油田进行污水处理工艺研究,以除油和悬浮物为主.即采用聚结除油-气浮-过滤的处理工艺,处理后的出水SS和含油量为5mg/L,达到回注水控制指标,经回注泵加压回注地层.     

Diffuse pollution loading from urban stormwater runoff in Daejeon city, Korea

In this paper, stormwater runoff from an urban watershed with combined sewer systems located in Daejeon metropolitan city, Korea, was characterized to measure the stormwater runoff discharge rates and pollutant concentrations. The observed averaged event mean concentrations (EMCs) of combined sewer overflows (CSO) were 536.1mg TSS/L, 467.7 mg TCODcr/L, 142.7 mg TBOD/L, 16.5mg TN/L, and 13.5mg TP/L. A detention basin was proposed to reduce CSO, and its essential design elements were discussed. The first flush significantly affected contaminant constituents in the descending order of suspended solid>organics>nutrients. Storage volumes for containing the first flush to improve water quality of the receiving stream can be estimated based on the total suspended solid loading. In this study, detention of the first flush equivalent to 5mm of precipitation could reduce CSO-induced diffuse pollution loading to a receiving water body by up to 80% of the total suspended solid loading.     

Irrigation of broccoli and canola with boron- and selenium-laden effluent

Selenium (Se), boron (B), and salinity contamination of agricultural drainage water is potentially hazardous for water reuse strategies in central California. To demonstrate the feasibility of using plants to extract Se from drainage water, Se accumulation was determined in canola (Brassica napus L.) and broccoli (Brassica oleracea L.) irrigated with drainage effluent in the San Joaquin Valley, California. In the 2-yr field study, both crops were irrigated with a typical drainage water containing Se (150 microg L(-1)), B (5 mg L(-1)), and a sulfate dominated salinity (EC of 7 dS m(-1)). Total dry matter yields were at least 11 Mg ha(-1) for both canola and broccoli, and plant tissue Se concentrations did not exceed 7 mg kg(-1) DM for either crop. Based on the amount of soluble Se applied to crops with drainage water and the estimated amount of soluble Se remaining in soil to a depth of 90 cm at harvest, both canola and broccoli accumulated at least 40% of the estimated soluble Se lost from the soil for both years. Applied Se not accounted for in plant tissue or as soluble Se in the soil was presumably lost by biological volatilization. This study suggests that irrigating two high value crops such as canola and broccoli with Se-laden effluent helps manage Se-laden effluent requiring treatment, and also produces economically viable Se-enriched crops. Future research should focus on managing residual salt and B in the soil for sustaining long time water reuse strategies.     

Anaerobic ammonium oxidation by Nitrosomonas spp. and anammox bacteria in a sequencing batch reactor

A sequencing batch reactor (SBR) was inoculated with mixed nitrifying bacteria from an anoxic tank at the conventional activated sludge wastewater treatment plant in Nongkhaem, Bangkok, Thailand. This enriched nitrifying culture was maintained under anaerobic conditions using ammonium (NH(4)(+)) as an electron donor and nitrite (NO(2)(-)) as an electron acceptor. Autotrophic ammonium oxidizing bacteria survived under these conditions. The enrichment period for anammox culture was over 100 days. Both ammonium and nitrite conversion rates were proportional to the biomass of ammonium oxidizing bacteria; rates were 0.08 g N/gV SS/d and 0.05 g N/g VSS/d for ammonium and nitrite, respectively, in a culture maintained for 3 months at 42 mg N/L ammonium. The nitrogen transformation rate at a ratio of NH(4)(+)-N to NO(2)(-)-N of 1:1.38 was faster, and effluent nitrogen levels were lower, than at ratios of 1:0.671, 1:2.18, and 1:3.05. Fluorescent in situ hybridization (FISH) was used to identify specific autotrophic ammonium oxidizing bacteria (Nitrosomonas spp., Candidatus Brocadia anammoxidans, and Candidatus Kuenenia stuttgartiensis). The ammonium oxidizing culture maintained at 42 mg N/L ammonium was enriched for Nitrosomonas spp. (30%) over Candidati B. anammoxidans and K. stuttgartiensis (2.1%) while the culture maintained at 210 mg N/L ammonium was dominated by Candidati B. anammoxidans and K. stuttgartiensis (85.6%). The specific nitrogen removal rate of anammox bacteria (0.6 g N/g anammox VSS/d) was significantly higher than that of ammonium oxidizing bacteria (0.4 g N/g Nitrosomonas VSS/d). Anammox bacteria removed up to 979 mg N/L/d of total nitrogen (ammonium:nitrite concentrations, 397:582 mg N/L). These results suggest significant promise of this approach for application to wastewater with high nitrogen but low carbon content, such as that found in Bangkok.     

Performance of a woodchip filter to treat dairy soiled water

The milking process on dairy farms produces wastewaters, known as dairy soiled waters (DSW), which contain variable concentrations of nutrients. The most common method of disposal is by application to land. However, this practise can result in the pollution of nearby receiving water bodies. A laboratory study, comprising two sets of 0.5?m, 1?m and 1.5?m-deep filters loaded at two loading rates, examined the performance of woodchip filters in treating DSW. The filters comprised de-barked Sitka spruce (Picea sitchensis) woodchips. Dried DSW was reconstituted to 1% and 3% suspended solids (SS) concentrations and was applied at 28?L/m(2).d to the surface of the filters at loading rates of 280?g?SS/m(2).d and 840?g?SS/m(2).d, respectively. Filters were loaded for a maximum of 277 days. The filters achieved substantial decreases in SS (>99%), chemical oxygen demand (COD) (>97%) and total nitrogen (TN) (>89%). The dominant treatment mechanism appears to be physical filtration, but sorption and biological uptake likely also play a role. As the filters are aerobic, mineralisation and nitrification occur, but gaseous N losses are probably not significant. Woodchip shows potential as a filter medium for treating DSW, significantly decreasing the concentrations of SS, COD and TN.     

炼油污水的处理

采用接触氧化—曝气生物滤池—加氯氧化—砂滤—活性炭吸附的工艺对某炼油厂污水进行处理,运行结果显示:出水中石油类和SS均小于5mg/L,达到了设计回用指标;而对COD和氨氮的降解则存在不稳定现象,针对此问题作了进一步的工艺整改后此工艺最终出水可以达到该厂制定的回用水质标准。     

The performance of constructed wetlands treating primary, secondary and dairy soiled water in Ireland (a review)

In Ireland, no database detailing the design, influent loading rates or performance of constructed wetlands (CWs) exists. On account of this, they are designed without any protocol based on empirical data. The aim of this paper was to provide the first published data on the performance of free-water surface flow (FWSF) CWs treating primary and secondary-treated municipal wastewater, and agricultural dairy soiled water (DSW) in Ireland. In total, the performance of thirty-four FWSF CWs, comprising fourteen CWs treating primary-treated municipal wastewater, thirteen CWs treating secondary-treated municipal wastewater, and seven CWs treating DSW, were examined. In most CWs, good organic, suspended solids (SS) and nutrient removal was measured. At an average organic loading rate (OLR) of 10 and 9 g biochemical oxygen demand (BOD) m(-2) d(-1), CWs treating primary and secondary wastewater removed 95 and 84% of influent BOD. Constructed wetlands treating DSW had an average BOD removal of 98%. At average SS loading rates of 6 and 14 g m(-2) d(-1), CWs treating primary and secondary wastewater had a 96 and an 82% reduction, and produced a final effluent with a concentration of 14 and 13 mg L(-1). Constructed wetlands treating DSW produced a final effluent of 34 mg L(-1) (94% reduction). Similar to other studies, all CWs examined had variable performance in ammonium-N (NH(4)(+)-N) removal, with average removals varying between 37% (for CWs treating secondary wastewater) and 88% (for CWs treating DSW). Variable ortho-phosphorus (PO(4)(3-)-P) removal was attributable to different durations of operation, media types and loading rates.     

Vetiver (Vetiveria zizanioides) responses to fertilization and salinity under irrigation conditions

Vetiver (Vetiveria zizanioides) has not been widely introduced in arid and semi-arid regions where irrigation, fertilization, and salinity are important factors in plant growth. The main objective of this study was to determine the response of vetiver to fertilization (fertigation) and salinity and their interactions under irrigated conditions. The experiment was conducted in a greenhouse in 10-L pots. Combined effects of three nutrients concentrations and three salinity levels of electrical conductivity (EC) 1, 3 and 6 dS/m in the irrigation water on growth and transpiration of vetiver plants and the content of different elements in their foliage were studied. Similar contents of 3.7 g/kg Na, 5.77 g/kg Ca and 2.55 g/kg Mg were found in the foliage of all the plants irrigated with the different fertilizer and salinity levels. Concentrations of 59 mg/L N and 36.1 mg/L K in the irrigation water were sufficient for vetiver plants needs at the different salinity levels tested. The salinity threshold (the maximum EC in the soil solution that does not cause a significant yield reduction) for vetiver was between 3 and 6 dS/m. A concentration of 15.2 mg/L P in the irrigation water was the optimum value for vetiver growth in the three salinity levels, resulting in an average content of 5.95 g/kg P in plant foliage. It is suggested that vetiver is sensitive to excess P (>8.66 g/kg). Increasing EC in the irrigation water to 6 dS/m decreased plant foliage biomass mainly due to an increase in the osmotic potential of the irrigation water and high Cl⁻ concentration in the foliage.     

内循环三相生物流化床处理生活污水的试验研究

对内循环三相生物流化床处理生活污水进行了试验研究,探讨了生物膜的形成和水力停留时间及曝气量对处理效果的影响。结果表明：在HRT为6h,曝气量为0.6m3/h,进水COD和NH4＋-N分别为240.2~298.7mg/L和29.1~68.9mg/L条件下,平均COD去除率为83%,NH4＋-N去除率为95.1%。     

Multivariate analysis of trace metal levels in tannery effluents in relation to soil and water: a case study from Peshawar, Pakistan

Tannery effluents and relevant ground water and soil samples collected from various tanning industries of Peshawar were analyzed for Na, Ca, K, Mg, Fe, Mn, Cr, Co, Cd, Ni, Pb and Zn by the AAS method. The metal concentration data for the three media are reported in terms of basic statistical parameters, metal-to-metal correlations and linear regression analyses. Metal distributions in the three media were quite divergent and showed non-normal distributions with high standard deviation and skewness parameters. Sodium exhibited the highest mean levels of 1,277mg/L, 881mg/L and 12,912mg/kg in the effluent, ground water and soil samples, respectively. Among other metals, Cr concentrations were 410mg/L, 0.145mg/L, 100mg/kg and Ca, 278mg/L, 64.8mg/L, and 2,285mg/kg in the effluent, ground water and soil samples, respectively. Some significant correlations were observed between effluent and soils in terms of Na, Cr, Ni, Co and Pb. The ground water-soil interrelationship suggested that Na levels in the soil and ground water were significantly correlated with each other (r=0.486, P<0.01). Similarly, Cr in the soil is strongly correlated with Ca in ground water (r=0.486, P<0.01). These results were duly supported by the linear regression analysis of data. The source identification studies conducted using Principal Component Analysis (PCA) and Cluster Analysis (CA) evidenced that ground water and soil were being contaminated by the toxic metals emanating from the tannery effluents.