Treatment and utilization of septic tank effluent using vertical-flow constructed wetlands and vegetable hydroponics

Vertical flow constructed wetlands is a typical ecological sanitation system for sewage treatment. The removal rates for COD, BOD 5, SS, TN, and TP were 60%, 80%, 74%, 49% and 79%, respectively, when septic tank effluent was treated by vertical flow filter. So the concentration of COD and BOD\-5 in the treated effluent could meet the quality standard for irrigation water. After that the treated effluent was used for hydroponic cultivation of water spinach and romaine lettuce, the removal efficiencies of the whole system for COD, BOD\-5, SS, TN and TP were 71 4%, 97 5%, 96 9%, 86 3%, and 87 4%, respectively. And it could meet the integrated wastewater discharge standard for secondary biological treatment plant. It was found that using treated effluent for hydroponic cultivation of vegetables could reduce the nitrate content in vegetables. The removal rates for total bacteria and coliform index by using vertical flow bed system with cinder substrate were 80%—90% and 85%—96%, respectively.

Performance of hybrid constructed wetland systems for treating septic tank effluent

The integrated wetland systems were constructed by combining horizontal-flow and vertical-flow bed, and their purification efficiencies for septic tank effluent were detected when the hydraulic retention time （HRT） was 1 d, 3 d, 5 d under different seasons. The results showed that the removal efficiencies of the organics, phosphorus were steady in the hybrid systems, but the removal efficiency of total nitrogen was not steady due to high total nitrogen concentration in the septic tank effluent. The average removal rates of COD （chemical oxygen demand） were 89%, 87%, 83%, and 86% in summer, autumn, winter and spring, respectively, and it was up to 88%, 85%, 73%, and 74% for BOD5 （5 d biochemical oxygen demand） removal rate in four seasons. The average removal rates of TP （total phosphorous） could reach up to 97%, 98%, 95%, 98% in four seasons, but the removal rate of TN （total nitrogen） was very low. The results of this study also indicated that the capability of purification was the worst in winter. Cultivating with plants could improve the treated effluent quality fTom the hybrid systems. The results of the operation of the horizontal-flow and vertical-flow cells （hybrid systems） showed that the removal efficiencies of the organics, TP and TN in horizontal-flow and vertical-flow cells were improved significantly with the extension of HRT under the same season. The removal rate of 3 d HRT was obviously higher than that of 1 d HRT, and the removal rate of 5 d HRT was better than that of 3 d HRT, but the removal efficiency was not very obvious with the increment of HRT. Therefore, 3 d HRT might be recommended in the actual operation of the hybrid systems for economic and technical reasons.

Theoretical Analysis of Biogas Production from Septic Tanks: The Case of the City of Kinshasa

As many think that respect for the environment, is not only a question intended for industrialists but has all the sectors of life, in particular sanitary also. In this regard, our article brings alternative management of human waste (excrement) to solve the problems that plague our dear beautiful capital, namely: 1) Lack of latrines that meet the standards;2) Emptying of septic tanks directly into the gutters and;3) Water pollution by sewage csompanies. In order to carry out the cartographic analysis of the study area, we used Shapefile data from the OpenStreetMap, Diva-Gis. These different data allowed us, analyzed, to categorize with the software ArArcGIS 0.8.1 to produce different zones according to the cases incurred in the city of Kinshasa. To do this, the analytical method uses the Buswell equation to determine the amount of gas contained in human excrement. Focusing on the analysis of the excrements produced by the population of age superior to 10 years, for 2023, we obtained: 138355.7283 m3/day of CH4 (885476.66 kWh/day or 885.476 MWh/day), which, energy can light: 138,355 lamps of 60 to 100 W for six hours or nearly 70,000 lamps of 60 to 100 W for 12 hours. Considering the last one which offers the lowest access rate, i.e. 3% of the district population to these latrines, we have: a) In Tshangu, we produce: 1618.762 3>/day (10360.07 kWh/day or 10.36 MWh/day) which can light nearly 1600 lamps from 60 to 100 W for six hours or nearly 800 lamps from 60 to 100 W for twelve hours. b) Mont-Amba, we produce 1402.927 3>/day (8978.73 kWh/day or 8.97 MWh/day) which can light nearly 1400 lamps from 60 to 100 W for six hours or nearly 700 lamps from 60 to 100 W for twelve hours;c) In Lukunga, we produce: 946.35 3>/day (6056.66 kWh/day or 6.056 MWh/day) which can light nearly 900 lamps from 60 to 100 W for six hours or nearly 450 lamps from 60 to 100 W for twelve hours. d) Funa, we produce: 182.629 3>/day (1168.83 kWh/day or 1.17 MWh/day) which can light almost 180 lamps from 60 to 100 W for six hours or almost 90 lamps from 60 to 100 W for twelve hours.

Biodegradation Potential of Some Bacteria and Fungi Isolates from Septic Tank Sewage in Some Related Sites in Delta and Edo States of Nigeria

The biodegradation potentials of some selected bacteria isolated from septic tank sewage in the region under study were examined. Three replicate samples from Locations A, B and C representing Agbor, Benin and Sapele regions of Delta and Edo States, Nigeria respectively were collected from the influent tank (raw sewage) between November 2018 and January 2019 for testing. The sewage in 10 ml septic tubes for both experimental and control samples was subjected to shake flask biodegradation analysis using the isolates with the highest screen test result. A total of 18 bio-treatment options were available in this study. In the shake flask biodegradation of sewage using isolates, total organic carbon (TOC) values from day 0 to 25 in all isolates were lower compared with the control experiments. TOC values at day 25 were lowest (0.10 mg/L) in the treatment containing Bacillus sp. + Klebsiella sp. as compared to the TOC value (2.01 mg/L) of the treatment which had Aeromonas sp. + Bacillus sp. + Klebsiella sp. pH, EC, COD, TDS, DO and BOD were also monitored for a period of 3 weeks. In all treatment options, there was a rapid increase in the BOD for the experimental set up around day 10 - 20 which ranged between 74.82 - 187.54 mg/L. The overall physical observation (odour, consistency and colour) of the experimental and the control septic tubes showed very high remarkable reductions in the experimental set-up when compared with the observation made for the control samples.

An innovative design of septic tank for wastewater treatment and its performance evaluation： An applicable model for developing countries

A study was carried out to evaluate the treatment efficiency of modified model of septic tank（ST）for the treatment of domestic wastewater.The objective was to explore the possibility of increasing the removal efficiency,at household level,thereby reducing cost and treatment burden on city level treatment plants.For this purpose,a bench scale model of ST was prepared and operated continuously for 78 days at different detention times i.e.,48,24 and 12 h and at two reactor temperatures viz.15℃ and 25℃.Domestic wastewater was fed to the bench scale ST without pre-settling.Research was conducted under two different arrangements.Firstly,by installing baffles in the bench scale ST（called Run-1 setup）,and secondly by installing perforated plates between the baffles（called Run-2 setup）.Results demonstrated that Run-2 setup is better than Run-1 setup.Temperature significantly affects the efficiency.Detention time of 24 h was found feasible.Run-2 setup demonstrated a percentage BOD removal of 45%with effluent BOD of 113 mg·L^-1 at 15℃ and 85%removal with effluent BOD of 31 mg·L^-1 at 25℃.It is concluded that if a modified design of ST using Run-2 setup is provided at household level,the effluent coming out of the house will meet the National Environmental Quality Standards（NEQS）when reactor temperature is close to 25℃.Development authorities are suggested to change their by-laws and make modified ST mandatory for all households.This may significantly reduce the cost and footprint of city level wastewater treatment plants being planned.

五格式净粪池与三格式化粪池处理农村生活污水效果及成本对比

针对三格式化粪池(TcST)出水COD及氮、磷浓度高,直排或溢流造成当地局部水体污染或黑臭的问题,构建了等容积五格式净粪池(FcPTR),并以实际生活污水为处理对象,对比研究2种反应器的运行特性和单位污染物去除成本。结果表明:FcPTR连续运行120 d,出水COD平均值为74 mg/L,TN、NH_(4)^(+)-N、TP平均浓度分别为26、20、1.6 mg/L,在我国进水水质相似的农村地区使用时,可满足11个省(区、市)发布的农村生活污水处理设施水污染排放地方标准二级水质要求。厌氧折流区、好氧区填料与污泥上变形菌门(Proteobacteria)的生长代谢促进了含氮和含磷物质的去除。相比于TcST,FcPTR明显增强了系统对有机物的降解和脱氮除磷效果,提高了系统的抗冲击负荷能力。经成本核算,在设计容积和运行场景相同时运行10年,FcPTR削减1 kg COD、1 kgNH_(4)^(+)-N的成本均比TcST降低19.8%。

化粪池对城市排水系统水质水量及H_(2)S排放的影响

选择重庆市主城区住宅小区实地调研,对住宅小区化粪池进出口的污水水质、流量、H_(2)S等指标进行实测,分析取消化粪池对排水系统和周边环境的综合影响。结果表明:(1)从流量看,无论是工作日还是周末化粪池前后流量相差不大,取消化粪池对进入市政管网的污水总量影响不大;(2)从水质看,化粪池对COD、BOD_(5)、SS有较高削减率,且COD/TN的平均下降率为43%,COD/TP的平均下降率为38%;(3)从H_(2)S看,化粪池内H_(2)S平均浓度为8.20 mg/m^(3),污水管道内H_(2)S平均浓度为2.70 mg/m^(3),取消化粪池可有效降低可被人体感官明显察觉的臭气逸散的风险,对改善小区整体环境有积极效益。

城镇高质量发展背景下化粪池取舍的探讨

目前,我国新型城镇化进程已迈入高质量发展阶段,城市更新、老旧小区改造、管网提质增效等项目正在稳步持续推进。在这些项目的实施过程中,关于化粪池的取消和改造一直是热点和难点问题。文章首先系统地分析了化粪池的设置初衷与现状问题,探讨化粪池取消的可行性和相应对策,最后提出,在市政污水管道质量较好的区域,管网末端已建成污水集中处理厂,可以不设化粪池;取消化粪池的地区,应重点针对小区内部的排水设施做好相应的保障措施;对于现存化粪池,应加强清掏管理和无害化处置。

基于实地调研的武汉市黄陂区红联村公共厕所设计研究

近些年随着乡村振兴的快速发展,农民生活质量的不断提高,对农村公共设施的需求正不断提升。但当前大多数农村缺乏公共厕所,少数有公共厕所的又不够完善。基于实地调研的方法,以武汉市黄陂区红联村的5座老旧公共厕所为调研对象,通过图表梳理出各种如厕痛点。采用装配式公共厕所,吊装式公共厕所2种方式进行红联村农村公共厕所的改造设计。同时运用三格化粪池的粪便处理方式,对红联村农村公共厕所进行无害化处理。期望能为武汉地区农村公共厕所的设计及建造提供有益借鉴。

组合式钢筋混凝土化粪池施工技术

目前,钢筋混凝土化粪池常采用两种施工方案,传统现浇施工方案和预制组合式钢筋混凝土成品化粪池施工方案,论文从工期、质量、安全、环保和工程造价5个方面对两种方案进行对比分析,详细介绍了组合式钢筋混凝土化粪池施工技术。

混合基质垂直流人工湿地净化废水效果

利用两种混合基质(蛭石+高炉渣、陶粒+高炉渣)构建模拟垂直流人工湿地处理化粪池出水,运行1a试验结果表明,蛭石+高炉渣基质对总鳞(TP)、总氮(TN)、NH4+-N、CODCr的去除效果要好于陶粒+高炉渣系统,而且其4个组合系统对TP、TN、CODcr、NH4+-N去除率分别大于71%、2.5%、61%、65%;水力学负荷比污染物的去除率存在密切关系:CODcr、NH4+-N、TP在水力负荷较小(30.6cm/d)时的去除率比水力负荷61.2cm/d下高;而种植美人蕉的蛭石+高炉渣组合在水力负荷为30.6cm/d,停留时间为0.848d时的处理效果较好,其对NH4+-N、TP、CODcr的去除率分别为94.51%、89.13%、66.46%,均达到了《城镇污水处理厂污染物排放标准》(GB18918-2002)一级B标准。

水平流-垂直流复合人工湿地系统对污水的净化效果研究

采用人工处理池,将水平流与垂直流湿地系统组合成复合式人工湿地处理系统,研究了此系统在停留时间为5d时对城市污水的净化效果。结果表明,水平流-垂直流复合人工湿地系统处理效果相当稳定,其对化粪池出水中COD,BOD5,TP,TN,SS的平均去除率分别为72%,80%,83%,33%和60%以上。而种植系统去除效果明显高于无种植系统。

生活污水土壤渗滤就地处理技术研究进展

生活污水就地土壤渗滤处理系统由化粪池和土壤渗滤系统耦合而成,其设备简单、投资少、操作管理方便、能耗低、净化效果好,特别适用于污水管网不完备的区域,处理分散排放的生活污水。本文阐述了生活污水就地土壤渗滤处理技术的新进展,提出了该系统在运行中需要强调的问题。

垂直流人工湿地系统对污水磷的净化效果

用煤灰渣人工土壤和风车草组成的垂直流人工湿地系统对化粪池出水中总磷和无机磷的去除率分别达到75 %— 92 %和 73%— 92 % ,其处理出水中总磷和无机磷浓度大部分低于 1mg/L ,达到了城市污水二级生化处理的二级排放标准。垂直流煤灰渣人工湿地系统对磷的去除作用主要有 :物理作用、化学吸附与沉淀作用和微生物同化作用以及植物摄取等作用 ,其对化粪池出水中总磷的去除率分别为 2 2 .8%、5 0 %— 6 5 %和 1%— 3%。

夏季猪场污水贮存过程中CO_2、CH_4排放试验

猪场粪污是重要的温室气体排放源,针对中国缺乏猪场污水贮存过程中温室气体排放参数的问题,该文选择温度较高的夏季,利用动态箱法于2007年6月对猪场的三格式化粪池进行了CO2、CH4气体排放测试。测试结果表明:当大气平均温度为28.4℃时,86%的温室气体排放源于一级和二级化粪池,一级、二级和三级化粪池的温室气体排放通量分别为407.5、383.0、127.7g/(m2·h)二氧化碳当量;CH4是本污水贮存单元中产生的主要的温室气体,一、二、三级化粪池排放的温室气体总量中,CH4排放的贡献率分别为95%、96%、95%,控制一、二级化粪池甲烷排放将大幅度减少猪场污水温室气体排放。

江苏农村“三格式”化粪池污水处理效果评价

"三格式"化粪池是江苏农村改厕中普遍使用的1种污水处理方式,约占全省农村卫生厕所的50%,其处理效果直接影响农村水环境质量。在江苏省9个县(市、区)中选取168户农民正常使用的"三格式"化粪池作为研究对象,于2006年6月至8月每隔5 d、连续3次分别在其进、出口采取水样进行监测、分析。结果表明,"三格式"化粪池对CODC r、TN和TP的去除率分别为48.51%、6.83%和23.92%;苏南地区好于苏中地区,苏北地区最差;"三格式"化粪池处理效果差于沼气化粪池,处理后的尾水未达国家污水排放标准,排入环境会造成较大影响。

化粪池污水处理能力研究及其评价

通过对西北地区典型城市兰州市某居民区化粪池的调查,分析了生活污水通过化粪池后水质的变化及其对各污染指标的去除率.结果表明,生活污水经化粪池处理后,CODCr、BOD5、总氮、总磷、动植物油浓度均有降低,年平均去除率分别达到83.6%,51.1%,64.3%,68.2%,75.6%.污水的可生化性有明显提高.研究结果对于全面评价化粪池的功能特征,进而为化粪池的取舍提供技术参考.

美国分散式污水处理的历史、现状与未来

以强调回收污水中资源与能源的可持续污水处理理念,使得分散式污水处理技术再次显出勃勃生机。污水分散式处理特别适合于那些远离城市下水管网的住宅小区、别墅、乡镇住宅等场合,它们能从源头控制污染、回收资源与能源。因此,分散式是一种与集中式并行的污水处理方式,是集中式污水处理的有效补充。以美国为例,介绍了分散式污水处理的发展历史、应用现状和未来发展趋势。

复合式竹丝填料生物反应器处理化粪池出水

为寻找适合化粪池出水的处理工艺,采用批式试验研究了复合式竹丝填料生物反应器对化粪池出水中COD、SS的去除效果。结果表明:复合式竹丝填料生物反应器能有效去除化粪池出水中的COD和SS,平均去除率分别达到了85.4%和90%以上;复合式竹丝填料生物反应器的微生物数量较多、微生物链较长、微生物种群丰富;复合式竹丝填料生物反应器中的污泥增加量极少。将复合式竹丝填料生物反应器内的活性污泥和竹丝分开组成两个独立的生物反应器并处理化粪池污水,结果发现,竹丝生物膜反应器能在短期(18h)内超过活性污泥反应器的处理效果,且竹丝生物膜反应器的产泥量很低。可见,竹丝填料较为适合处理化粪池出水,是一种价格低廉、污染少、运行管理费用较低的良好填料。

三格化粪池厕所的功能定位及在农村改厕中的应用误区

三格化粪池厕所因价格低廉、运维简便,成为当前欠发达地区农村厕所革命的主要技术模式,但在实际应用中普遍存在对其功能定位的认识误区,对化粪池后期的正确使用、粪污的无害化处理及粪肥有效回用造成了不良影响。因此,本文通过溯源化粪池发展历程,分析其在不同卫生模式下的功能定位,并揭示三格化粪池厕所具有卫生性和环保性的历史使命。在此基础上,通过剖析部分地区当前农村改厕存在的3个典型误区,即采用普通水冲式便器、"管道收集+(集中型)大化粪池"和"收集+异地脱水干燥制肥"应用模式的问题,指出需重视化粪池正确利用,并结合农村改厕中化粪池应用提出合理化建议。