土壤过滤系统处理农村生活污水的 试验研究

采用一种土壤过滤系统处理农村生活污水,考察了该工艺对CODCr、BOD5、NH3-N、全氮（TN）和全磷（TP）的去除效果。实验结果表明,当水力负荷约为0.05 m3/（m2·d）, 水力停留时间为3 d时。该土壤过滤系统对CODCr、BOD5、NH3-N、全氮（TN）和全磷（TP）的去除效果较好,平均去除率分别达到84.6%、83.3%、64.3%、59.8%和70%。出水CODCr约为18.3~42.1 mg/L,BOD5约为8.9~17.3 mg/L,NH3-N约为11.2~17.7 mg/L,TN约为21.2~31.3 mg/L,TP小于2.0 mg/L,出水水质优于农田灌溉水质标准（GB 5084—2005）。气温变化和进水污染物浓度对处理效果影响明显。总体上来讲,温度大于22 ℃时,进水污染物浓度越低处理效果越好。     

MBR工艺处理城镇污水处理厂污泥水中试研究

将平板膜组件与传统脱氮除磷工艺相结合,构建了膜生物反应器强化生物脱氮除磷中试系统,并用于处理城镇污水处理厂的污泥系统废水。结果表明,出水CODCr、BOD5、NH3—N、TN和TP的平均浓度分别为70.8 mg/L、8.7 mg/L、15.1 mg/L、29.7 mg/L和0.38 mg/L,达到或接近了《城镇污水处理厂污染物排放标准》(GB 18918—2002)的一级标准。     

Operation of a full-scale pumped flow biofilm reactor (PFBR) under two aeration regimes

A novel technology suitable for centralised and decentralised wastewater treatment has been developed, extensively tested at laboratory-scale, and trialled at a number of sites for populations ranging from 15 to 400 population equivalents (PE). The two-reactor-tank pumped flow biofilm reactor (PFBR) is characterised by: (i) its simple construction; (ii) its ease of operation and maintenance; (iii) low operating costs; (iv) low sludge production; and (v) comprising no moving parts or compressors, other than hydraulic pumps. By operating the system in a sequencing batch biofilm reactor (SBBR) mode, the following treatment can be achieved: 5-day biochemical oxygen demand (BOD5), chemical oxygen demand (COD) and total suspended solids (TSS) reduction; nitrification and denitrification. During a 100-day full-scale plant study treating municipal wastewater and operating at 165 PE and 200 PE (Experiments 1 and 2, respectively), maximum average removals of 94% BOD5, 86% TSS and 80% ammonium-nitrogen (NH4-N) were achieved. During the latter part of Experiment 2, effluent concentrations averaged: 14 mg BOD5/l; 32 mg COD(filtered)/l; 14 mg TSS/l; 4.4 mg NH4-N/l; and 4.0 mg NO3-N/l (nitrate-nitrogen). The average energy consumption was 0.46-0.63 kWh/m3(treated) or 1.25-1.76 kWh/kg BOD5 removed. No maintenance was required during these experiments. The PFBR technology offers a low energy, minimal maintenance technology for the treatment of municipal wastewater.     

Design and operation of an eco-system for municipal wastewater treatment and utilization.

An eco-system consisting of integrated ponds and constructed wetland systems is employed in Dongying City, Shandong Province for the treatment and utilization of municipal wastewater with design capacity of 100,000 m(3)/d. The total capital cost of this system is 680 Yuan (RMB) or US dollars 82/m(3)/d, or about half that of the conventional system based on activated sludge process, and the O/M cost is 0.1 Yuan (RMB) or US dollars 0.012/m(3), only one fifth that of conventional treatment systems. The performance of the wastewater treatment and utilization eco-system is quite good with a final effluent COD, BOD, SS, NH3-N and TP of 45-65 mg/l, 7-32 mg/l, 12-35 mg/l, 2-13 mg/l and 0.2-1.8mg/l respectively and the annual average removals of COD, BOD, SS, NH3-N and TP are 69.1%, 78.3%, 76.4%, 62.1% and 52.9%o respectively, which is much better than that of conventional pond system or constructed wetland used separately and illustrates that the artificial and integrated eco-system is more effective and efficient than the simple natural eco-system.     

A~2/O—MBR污水处理系统运行特性研究

北方某城市污水处理厂采用A2/O—MBR组合工艺,对污水处理厂半年内的实际运行数据进行分析,研究了主要运行参数对工艺的影响以及组合工艺对各种污染物的去除效果,可得系统出水CODCr、NH3—N、TP分别为30 mg/L1、mg/L、0.37 mg/L,去除率分别为90%、94%、91%,出水水质达到《城市污水再生利用城市杂用水水质》(GB/T 18920—2002)要求,系统运行稳定,并具有较强的耐冲击负荷能力。     

ANAMMOX工艺在生活污水深度处理中的应用研究

随着水环境质量的恶化,高能低耗的污水深度处理技术成为当前研究热点,尤其是对于低C/N比的城市生活污水脱氮技术的研究。试验以城市生活污水的二级出水为研究对象,采用ANAMMOX下向流生物滤池,当二级出水NH3-N=15-35mg/L,CODCr=25-45mg/L,TOC=9-12mg/L,水温=25-28℃时,ANAMMOX下向流生物滤池脱氨率达80%-100%,不仅适用于处理高氨废水,也可用于城市生活污水深度处理中。试验发现pH可以用来指示ANAMMOX反应的进行,同时也可以用来指示ANAMMOX反应进程的快慢。试验中还发现,厌氧氨氧化反应速率与NO2--N含量有关,原水中NO2--N含量的增多有利于ANAMMOX工艺处理效果。     

Effects of effluent recirculation in vertical-flow constructed wetland on treatment efficiency of livestock wastewater.

Enhancing the treatment efficiency of livestock wastewater by effluent recirculation is investigated in a pilot-scale vertical-flow constructed wetland. The wetland system is composed of downflow and upflow stages, on which narrow-leaf Phragmites communis and common reed Phragmites typhia are planted, respectively; each stage has a dimension of 4 m(2) (2 m x 2 m). Wastewater from the facultative pond is fed into the system intermittently at a flow rate of 0.4 m(3)/d. Recirculation rates of 0, 25%, 50%0, 100% and 150% are adopted to evaluate the effect of the recirculation rate on pollutants removal. This shows that with effluent recirculation the average removal efficiencies of NH4-N, BOD5 and SS obviously increase to 61.7%, 81.3%, and 77.1%, respectively, in comparison with the values of 35.6%o, 50.2%, and 49.3% without effluent recirculation. But the improvement of TP removal is slight, only from 42.3% to 48.9%. The variations of NH4-N, DO and oxidation-reduction potential (ORP) of inflow and outflow reveal that the adoption of effluent recirculation is beneficial to the formation of oxide environment in wetland. The exponential relationships with excellent correlation coefficients (R(2) > 0.93) are found between the removal rates of NH4-N and BOD5 and the recirculation rates. With recirculation the pH value of the outflow decreases as the alkalinity is consumed by the gradually enhanced nitrification process. When recirculation rate is kept constant at 100%, the ambient temperature appears to affect NH4-N removal, but does not have significant influence on BOD5 removal.     

Treatment of slaughterhouse plant wastewater by using a membrane bioreactor

The use of a membrane bioreactor (MBR) for removal of organic substances and nutrients from slaughterhouse plant wastewater was investigated. The chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) concentrations of slaughterhouse wastewater were found to be approximately 571 mg O2/L, 102.5 mg/L, and 16.25 mg PO4-P/L, respectively. A submerged type membrane was used in the bioreactor. The removal efficiencies for COD, total organic carbon (TOC), TP and TN were found to be 97, 96, 65, 44% respectively. The COD value of wastewater was decreased to 16 mg/L (COD discharge standard for slaughterhouse plant wastewaters is 160 mg/L). TOC was decreased to 9 mg/L (TOC discharge standard for slaughterhouse plant wastewaters is 20 mg/L). Ammonium, and nitrate nitrogen concentrations of treated effluent were 0.100 mg NH4-N/L, and 80.521 mg NO3-N/L, respectively. Slaughterhouse wastewater was successfully treated with the MBR process.     

Performance of constructed wetland treating wastewater from seafood industry.

Wastewater from seafood industry contains high concentrations of organic matter, nitrogen compounds, and solid matter. Constructed wetland can be used as tertiary treatment and for nutrient recycling. This research studied the performance of nitrogen and suspended solids removal efficiency of a constructed wetland treating wastewater from a seafood-processing factory located at Songkhla, southern Thailand. The existing constructed wetland has dimensions of 85 m, 352 m and 1.5 m in width, length and depth respectively, with an area of about 29,920 m2. The water depth of 0.30 m is maintained in operation with plantation of cattails (Typha augustifolia). Flow rate of influent ranged between 500-4,660 m3/d. Average hydraulic retention time in the constructed wetland was about 4.8 days. Influent and effluent from the constructed wetland were collected once a week and analyzed for pH, temperature, dissolved oxygen (DO), biochemical oxygen demand (BOD5), Suspended solid (SS), total Kjeldahl nitrogen (TKN), ammonia nitrogen (NH3-N), organic nitrogen (Org-N), nitrate (NO3-N), and nitrite (NO2-N). The average removal efficiencies of BOD5, SS, TKN, NH3-N, and Org-N were 84%, 94%, 49%, 52% and 82%, respectively. It was found that the constructed wetland acting as a tertiary treatment process provided additional removal of BOD5, SS and TKN from wastewater from the seafood industry.     

Performance evaluation of subsurface wastewater infiltration system in treating domestic sewage

This study was to investigate domestic treatment efficiency of a subsurface wastewater infiltration (SWI) system over time. The performances of a young SWI system (in Shenyang University, China, fully operated for one year) and a mature SWI system (in Shenyang Normal University, China, fully operated for seven years) under the same operation mode were contrasted through field-scale experiments for one year. The performance assessment for these systems is based on physical and chemical parameters collected. The removal efficiencies within the young system were relatively high if compared with the mature one: for biochemical oxygen demand (BOD), chemical oxygen demand (COD), suspended solids (SS), ammonia nitrogen (NH(3)-N) and total phosphorus (TP) were 95.0, 89.1, 98.1, 87.6 and 98.4%, respectively. However, the removal efficiencies decreased over time. The mean removal efficiencies for the mature SWI system were as follows: BOD (89.6%), COD (87.2%), SS (82.6%), NH(3)-N (69.1%) and TP (74.4%). The results indicate that the mature SWI system successfully removed traditional pollutants such as BOD from domestic wastewater. However, the nutrient reduction efficiencies (including NH(3)-N and TP) decreased after seven years of operation of the mature SWI system. Meanwhile, the SWI system did not decrease the receiving surface water quality.     

Effect of recirculation on organic matter removal in a hybrid constructed wetland system

This research project aimed to determine the technologically feasible and applicable wastewater treatment systems which will be constructed to solve environmental problems caused by small communities in Turkey. Pilot-scale treatment of a small community's wastewater was performed over a period of more than 2 years in order to show applicability of these systems. The present study involves removal of organic matter and suspended solids in serially operated horizontal (HFCW) and vertical (VFCW) sub-surface flow constructed wetlands. The pilot-scale wetland was constructed downstream of anaerobic reactors at the campus of TUBITAK-MRC. Anaerobically pretreated wastewater was introduced into this hybrid two-stage sub-surface flow wetland system (TSCW). Wastewater was first introduced into the horizontal sub-surface flow system and then the vertical flow system before being discharged. Recirculation of the effluent was tested in the system. When the recirculation ratio was 100%, average removal efficiencies for TSCW were 91 +/- 4% for COD, 83 +/- 10% for BOD and 96 +/- 3% for suspended solids with average effluent concentrations of 9 +/- 5 mg/L COD, 6 +/- 3 mg/L BOD and 1 mg/L for suspended solids. Comparing non-recirculation and recirculation periods, the lowest effluent concentrations were obtained with a 100% recirculation ratio. The effluent concentrations met the Turkish regulations for discharge limits of COD, BOD and TSS in each case. The study showed that a hybrid constructed wetland system with recirculation is a very effective method of obtaining very low effluent organic matter and suspended solids concentrations downstream of anaerobic pretreatment of domestic wastewaters in small communities.     

An innovative technology based on aerobic granular biomass for treating municipal and/or industrial wastewater with low environmental impact.

The paper reports the results of an investigation carried out at lab scale to assess the effectiveness of an innovative technology (SUPERBIO) for treating municipal and/or industrial wastewater. When this technology was applied for treating municipal wastewater, the results showed that even at maximum organic load (i.e. 7 kg COD m(-3) d(-1)), the COD in the treated effluent was lower than 50 mg L(-1). In addition, both ammonia and TKN removal efficiencies resulted in higher than 87% up to an organic load of 5.7 kg COD m(-3) d(-1) corresponding to a nitrogen load of 0.8 kg TKN m(-3) d(-1). Very satisfactory process performances also resulted during tannery wastewater treatment, when a chemical oxidation step (i.e. ozonation) was inserted in the treatment cycle of SUPERBIO. In such an instance, at organic and nitrogen loadings of 3 kgCOD m(-3) d(-1) and 0.20 kg N m(-3) d(-1), COD, NH4+ -N and TSS average removals were 96, 99 and 98%, respectively. Finally, during the whole experimentation, SUPERBIO was always characterised by a very low sludge production. Such a result was ascribed mainly to the characteristics of biomass that grew in the form of very dense granules (i.e. 130 gVSS L(Biomass)(-1) allowing a biomass concentration as high as 50-60 gTSS l(bed)(-1) to be achieved.     

Behaviour of a full-scale expanded bed reactor with overlaid anaerobic and aerobic zones for domestic wastewater treatment.

This paper presents the behaviour of a full-scale expanded bed reactor (160 m3) with overlaid anaerobic and aerobic zones used for municipal wastewater treatment. The research was carried out in two experimental steps: anaerobic and anaerobic-aerobic conditions, and the experimental results presented in this paper refer to four months of reactor operation. In the anaerobic condition, after inoculation and 60 days of operation, the reactor treating 3.40 kg CODm(-3)d(-1) for thetaH of 2.69 h, reached mean removal efficiencies of 76% for BOD, 72% for COD, and 80% for TSS, when the effluent presented mean values of 225 mg.L(-1) of COD, 98 mg.L(-1) of BOD and 35 mg.L(-1) of TSS. Under these conditions, for nitrogen loading of 0.27 kgN.m(-3)d(-1), the reactor generated an effluent with mean N-org. of 8 mg.L(-1) and N-ammon. of 37 mg.L(-1), demonstrating high potential of ammonification. For the anaerobic-aerobic condition (118th day) the system was operated with thetaH of 5.38 h presented mean removal efficiencies of 84% for BOD, 79% for COD, 76% for TSS, and 30% for TKN. The reactor's operation time was less than two months, which was not long enough to reach nitrification. Regarding the obtained results, this research confirmed that this reactor is configured as a flexible and adequate alternative for the treatment of sewage, requiring relatively small area and only thetaH of 10 h that can be adjusted to the local circumstances.     

Performance improvement of hybrid membrane bioreactor with PAC addition for water reuse.

A study was carried out on a hybrid (AS-SBF) membrane bioreactor (HMBR) for the municipal wastewater reclamation and reuse at Chengfengzhuang WWTP in Daqing City, Heilongjiang Province. It was found that the effects of DO and water temperature on performance of the HMBR was significant. Under the conditions of water temperature in range of 10-14 degrees C, pH of 6.6- 7.0, DO of 4-6 mg/l and HRT of 7 h, the HMBR exhibited removal efficiencies for CODcr, BOD5, NH3-N and TN of 96.7%, 98.9%, 93.7% and 60.5% respectively. The turbidity of effluent from HMBR was below 1 NTU. The effluent of HMBR meets the standard of wastewater reclamation for oil exploitation. PAC was added into the bioreactor at the second operating stage, in order to further research parameters variation. The flux was improved by 53.2%, compared to the membrane without PAC-addition, due to formation of a PAC pre-coat layer on the membrane surface, with lots of advantages such as larger granules, higher porosity, non-compressibility, higher filterability and easy removal, compared with pure biomass layer. In addition, the performance of HMBR was further improved, due to adsorption and degradation of SMPs, the average removal of CODcr and TN was further improved by 5.1% and 13.5% respectively. Biomass in the HMBR was quantitatively measured, of which the biofilm played a major role in pollutants removal.     

A pilot study on a step-feeding anoxic/oxic activated sludge system.

A four stage pilot plant of step-feed biological nutrient removal (BNR) was employed to investigate reactor performance and process stability. The results obtained showed that step-feed BNR is efficient and cost-effective for nitrogen and carbonaceous removal from municipal wastewater. The total average removal efficiencies of COD, NH3-N, TN and TP could reach as high as 89.5, 97.8, 73 and 75%, respectively, with 50% of return activated sludge (RAS), 9 h of hydraulic retention time (HRT) and 20 d of sludge retention time (SRT). Step-feed BNR is an alternative and effective technology of nutrient removal for municipal wastewater treatment.     

梯田式人工湿地处理生活污水的初步研究

针对山丘坡地的自然环境特点,提出构建梯田式人工湿地处理生活污水的方法,并通过实验装置对梯田式人工湿地处理生活污水的效果进行了初步研究。结果表明:当CODCr、NH4+-N、TP的进水质量浓度变化范围在182.3~286.7 mg/L、32.91~59.28 mg/L、1.23~3.05 mg/L时,其平均去除率分别为86.52%、80.5%、96.16%,出水质量浓度分别低于30mg/L、10mg/L、0.1mg/L;湿地基质中硝化菌、反硝化菌数量变化范围分别为1.5万~420万MPN/g、30万~1 860万MPN/g。与常规人工湿地相比,梯田式人工湿地具有较强的污染物去除能力,特别是具有高效的脱氮除磷效果。     

Treatment of strong nitrogen swine wastewater in a full-scale sequencing batch reactor.

Treatment of swine wastewater containing strong nitrogen was attempted in a full-scale SBR. The strongest swine wastewater was discharged from a slurry-type barn and called swine-slurry wastewater (SSW). Slightly weaker wastewater was produced from a scraper-type barn and called swine-urine wastewater (SUW). TCOD, NH4+-N and TSS in raw SSW were 23,000-72,000 mg/L, 3,500-6,000 mg/L and 17,000-50,000 mg/L, respectively. A whole cycle of SBR consists of 4 sub-cycles with anoxic period of 1 hr and aerobic period of 3 hr. The maximum loading rates of both digested-SSW and SUW were similar to 0.22 kg NH4+-N/m3/day whereas the maximum loading rates of raw SSW was up to 0.35 TN/m3/day on keeping the effluent quality of 60 TN mg/l. The VFAs portion of SCOD in raw SSW was about more than 60%. The VFAs in SUW and digested-SSW were about 22% and 15%, respectively. NH4+-N and PO4(3-)-P in SSW were removed efficiently compared to those in digested-SSW and DUW because SSW had high a C/N ratio and readily biodegradable organic. High concentration of organic was useful to enhance denitrification and P uptake. Also the amount of external carbon for denitrification was reduced to 5% and 10% of those for digested-SSW and SUW.     

移动式污水处理系统应用于分散生活污水的试验研究

针对分散型生活污水量小面广的特点,开发出移动式污水处理系统,系统由生化预处理池和车载式移动污水处理设备组成.中试结果表明,采用该组合工艺,出水CODCr＜40 mg/L,BOD5＜10 mg/L,TP＜0.5 mg/L,TN＜10 mg/L,NH3-N＜1 mg/L,其平均去除率分别达到86.69%,94.89%,89.40%,74.35%和97.89%.出水指标均能达到＜城镇污水处理厂污染物排放标准＞(GB 18918-2002)一级A排放标准.     

Effects of solid retention time on the performance of submerged anoxic/oxic membrane bioreactor.

In this study, four similar bench-scale submerged Anoxic/Oxic Membrane Bioreactors (MBR) were used simultaneously to investigate the effects of solids retention time (SRT) on organic and nitrogen removal in MBR for treating domestic wastewater. COD removal efficiencies in all reactors were consistently above 94% under steady state conditions. Complete conversion of NH(4+)-N to NO(3-)-N was readily achieved over a feed NH(4+)-N concentration range of 30 to 50 mg/L. It was also observed that SRT did not significantly affect the nitrification in the MBR systems investigated. The average denitrification efficiencies for the 3, 5, 10 and 20 days SRT operations were 43.9, 32.6, 47.5 and 66.5%, respectively. In general, the average effluent nitrogen concentrations, which were mainly nitrate, were about 22.2, 27.6, 21.7 and 13.9 mg/L for the 3, 5, 10 and 20 days SRT systems, respectively. The rate of membrane fouling at 3 days SRT operation was more rapid than that observed at 5 days SRT. No fouling was noted in the 10 days and 20 days SRT systems during the entire period of study.     

化学除磷-水解酸化-厌氧接触-接触氧化工艺处理榨菜废水

榨菜废水的高含盐量和高氮磷对微生物有较强的抑制作用,处理难度大.以处理规模400 m3/d的重庆某榨菜厂废水处理工程为例,其进水COD 3 000～4 000 mg/L,BOD5 1445 mg/L,盐度1.5％～2.5％(以NaCl计),氨氮80～120 mg/L,总磷25～30 mg/L.通过驯化耐盐微生物为主体菌种,采用化学除磷-水解酸化-厌氧接触-接触氧化工艺进行处理,出水COD、BOD5、氨氮、总磷以及盐度平均分别为70.5 mg/L、14.9 mg/L、9.4 mg/L、0.46 mg/L以及1.53％,可以达到《污水综合排放标准》(GB8978-1996)一级标准.