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Almost half of Indonesia's 238 million people live in urban areas, and most urban dwellers use on-site sanitation systems. Government policy recognizes the need for effective septage management systems but most existing septage treatment facilities are operating sub-optimally and less than 4 per cent of the faecal sludge generated is currently treated. This paper outlines the findings of field investigations of septage management in four cities undertaken by the World Bank's Water and Sanitation Program (WSP) as part of technical assistance to the Indonesian government. It summarizes the current faecal sludge management arrangements in the four cities, focusing particularly on the consequences of low demand for the financial viability of business models. Models based on ‘on-demand’ and scheduled tank desludging are explored in relation to their institutional and financial resource needs. The paper explores options for strengthening management systems and proposes an incremental approach to service improve...

Using the Contingent Valuation Method (CVM), the study looks at the septage management and sewerage services demand of households with latrines in Dagupan City, Philippines vis-à-vis the cost of providing these services. The survey covers a total of 1,200 respondents for the septage and sewerage demand study. For the septage and sewerage studies, income was shown to significantly influence willingness to pay (WTP). WTP was also found to increase across income groups, indicating the plausibility of implementing a socialized pricing scheme for the septage and sewerage fees. Another important implication of the results is that increased demand for sanitation facilities would only take place as general income levels of Dagupan City improve. Under certain assumptions, the individually rational and financially viable Septage Fee is around PhP 46/month with optimal desludging frequency of 3 yrs. This means that a self-financed Septage Program is possible for the city. However, the case is different for the Sewerage Program since none of the proposed fees (including the average WTP of PhP 102/month for the whole sample) is sufficient to cover the huge investment costs associated with a self-financed sewerage infrastructure. Thus, the Local Government Unit (LGU) has to source funds elsewhere.

Eight vertical flow small-scale constructed wetlands were introduced in a pre-existing wastewater treatment pilot plant consisting of three interconnected waste stabilization ponds—a facultative pond followed by two maturation/aerobic ones. The wetlands were identical in couples but differed in substrate and plant presence (common reed) and were fed from the outflow of the first maturation pond. The system was monitored for two years in order to study its operation and efficiency for the treatment of septage in an open air experiment. Samples were collected twice a month and TSS, BOD5, pH, EC, TP, N- and N- were monitored. BOD5 removal was greater in the summer months. The unplanted wetlands were more efficient in TSS and BOD5 concentrations removal. Still, when estimating the BOD5 mass in the constructed wetlands effluents using Thornthwaite model to adjust the results, it was found that the BOD5 mass of unplanted wetlands effluents is greater than that found in planted ones. The system did not ...

Population growth in rural Canada has resulted in an increase in municipal septage generation, which could overload existing treatment facilities that rely on biological treatment approaches. To address concerns associated with potential shock loading of these systems, three semi-passive wastewater treatment technologies were compared at the pilot-scale to identify a suitable approach to augment the capacity of an existing wastewater stabilization pond facility in rural Ontario. Two of these technologies, the BioDome and BioCord systems, were commercially available systems that make use of biofilm technology to improve treatment performance and enhance the robustness to temperature and hydraulic loading fluctuations. The third approach involved the use of the natural filtration capacity of zebra mussels to improve effluent quality. The three technologies were assessed against a control for reductions in regulated wastewater parameters with an emphasis on nutrient (ammonia/ammonium, orthophosphate) reductions, air cycling, energy consumption, and performance following exposure to anoxic conditions. The BioCord system was the only technology that was found to significantly outperform the control, exhibiting reductions of 69%, 47%, 77% and 81% for NH3/NH4+, TN, COD and TSS, respectively. The BioCord system also had the lowest maintenance and energy requirements, likely due to its design, which provided the biofilm with optimal oxygen and substrate contact. Consequently, the BioCord system could develop a more stable, heterogeneous microbial population and maintain high levels of activity in its biofilm, even during periods of extended anaerobic conditions. This also suggested that the BioCord system would require less aeration, and hence a lower energy expenditure, than the other systems. Furthermore, the BioCord system showed the fastest rates of recovery, reaching significant levels of parameter reductions within one week of system re-initiation.

Membrane electro-bioreactor (MEBR) was tested in pilot scale to evaluate its suitability to treat low wastewater flowrates in remote locations. The system treated municipal wastewater with highly variable, continuously changing concentrations of COD, ammonia and phosphorous. The MEBR combining biological, electrokinetic and membrane filtration processes allowed achievement of 90-99% of phosphorous, COD, and nitrogen. The results confirmed that MEBR could be applied to self–sustained building, separate dwellings, and in remote locations. It would be capable in substituting septic tanks, and used for mobile septage pre-treatment. It can be implemented in small and medium size municipalities, villages, mining or military camps as well as remote aboriginal population reserves.

This research is a study of Bangkok's sanitation system based on quantitative analysis of water and wastewater flow focusing on domestic sector. Nitrogen was quantified and assessed its distribution by Material Flow Analysis MFA. Field surveys and questionnaires for 300 households were conducted within three zones of Bangkok city inner city, urban fringe, and suburban. Nitrogen flow analysis revealed that the main pathways of nitrogen for greywater and blackwater were to sewerage system and onsite sanitation system OSS, respectively. With treatment facilities, wastewater from households was distributed into four facilities: OSS 44.51% N; decentralized wastewater treatment plants WWTPs 0.18% N; centralized WWTPs 4.80% N and septage treatment plants (STPs) 0.64% N. Simultaneously, nitrogen discharge to environment could reduce through OSS, decentralized WWTPs, centralized WWTPs and STPs from 26,011 to 4,540 ton N/year or at 82.55% reduction. In aspect of without treatment facilities, the remaining of wastewater was distributed to environment at 45.49% total wastewater from household. At the urban fringe zone, large wastewater flowed to environment without treatment 27.41% total wastewater from household. Meanwhile, septage was represented an important nutrient source. Non-treated septage distributed large amount of nitrogen 32.17% N with its small amount of flow into environment 1.92% total wastewater from household. Combinations of four treatment facilities including the OSS, decentralized WWTPs, centralized WWTPs and STPs were proposed as scenarios to reduce the existing discharge of 28,379.2 ton N/year to the environment. With the existing treatment facilities and practical scenario for each zone, nitrogen discharge could be reduce to 7,559.7 ton N/year 73.36% reduction with the strategies of centralized WWTPs for the inner city zone, the combination of decentralized and existing centralized WWTPs for the urban fringe zone, OSS for the suburban zone, and septage collection to STPs for all zones.

The Government of Ontario plans to ban the land application of untreated septage; however, most town wastewater treatment plants do not have the capacity to accept septage. A combined reed bed – freezing bed technology has been successfully developed to dewater and treat septage. Lab column studies established that freeze-thaw conditioning can restore drainage in clogged sand drying beds dosed with common biological sludges and that septage can be dosed at 10 cm/week for 2.5-5.0 months before clogging is observed. Pilot studies showed that freezing beds can operate without the need for a cover with the applied sludge effectively melting any snow cover in regions with moderate snowfall. Septage freezing was successfully modelled following an accepted model for ice formation on water bodies while septage thawing was modelled using a regression analysis with initial frozen depth and precipitation found to be insignificant and degree days of warming controlling the rate of thawing. Model results were utilized to produce a freezing bed design loading map for North America based on temperature normals. Field scale planted and unplanted reed bed – freezing bed systems were constructed and tested with varying hydraulic loading rates (1.9-5.9 m/y) and solid loading rates (43-144 kg/m2/y) over a 5 year period resulting in a recommended design hydraulic loading rate of 2.9 m/y or 75 kg/m2/y. Drainage rates doubled after freeze-thaw conditioning compared to during the growing season, suggesting that freeze-thaw conditioning restores filter hydraulic conductivity. No effect of solid loading rate, planted versus unplanted filters and 7 versus 21 d dosing cycles on filter drainage was observed; however, drainage varied significantly with hydraulic loading rate. The filters separated almost all contaminants with filtrate equivalent to a low-strength domestic wastewater which can be easily treated in any municipal or decentralized wastewater system. The dewatered sludge cake had similar nutrient and solid content to a solid dairy manure and met biosolid land application standards in terms of metals and pathogens. The combined reed bed-freezing bed technology can provide a low-cost solution for the treatment and reuse of septage in cold-climate regions.

Septage is the solid sludge that accumulates in septic tanks over a period of time. Many of the developing countries in the world face the challenging task of septage management. Due to the high variability in the nature of septage, there is a need to study its physical and chemical characteristics in order to suggest a sustainable treatment methodology. The present study deals with the characterization of septage collected from different locations of Chennai city in India, in two different seasons (summer and winter). The characterization includes parameters such as solids, organics, inorganics, nutrients and heavy metals. Septage showed significant difference in concentrations of pollutants from one season to the other (p > 0.05). The average total solids concentration is found to be 1.6 times higher during winter season than compared to summer season. Average concentrations of solids were 2185 ± 1070 and 3555 ± 2935 mg/L during summer and winter, respectively. Liquid characterization of septage showed total chemical oxygen demands (COD) of 905 ± 603 mg/L (summer) and 1460 ± 1295 mg/L (winter). Similarly, average soluble biochemical oxygen demand (sBOD) was found to be 117 ± 54 mg/L during summer and 211 ± 220 mg/L during winter season. Studies also showed that septage was rich in nutrients such as total nitrogen (4–500 mg/L), ammoniacal nitrogen (2–129 mg/L), total phosphate (5–236 mg/L) and heavy metals such as copper, zinc, lead and manganese. Overall characterization indicates that the collected septage samples are highly variable in nature with respect to sources, season and locations of collection. As the septage is rich in organic matter and nutrients, it can be used as a resource like soil conditioner or as a substitute for chemical fertilizer in agriculture, after proper treatment, leading to a new evolution in sanitation.

Resumo A destinação dos Lodos de Fossa e Tanque Séptico (LFTS) tem resultado em problemas ambientais e de saúde pública, devido principalmente à falta de alternativas adequadas para a destinação, e de fiscalização mais rigorosa. O problema se agrava em municípios desprovidos de estações de tratamento de esgoto, já que a disposição nesses sistemas tem sido a prática mais utilizada no país. Desta forma, a presente pesquisa teve por finalidade avaliar os efeitos da disposição desses lodos no desempenho, operação e manutenção de lagoas de estabilização que tratam lixiviados. O sistema estudado é composto por dois módulos idênticos de lagoa anaeróbia seguida de facultativa, de modo que o módulo receptor de LFTS foi submetido, durante seis meses, a diferentes taxas de aplicação volumétrica de lodo por lixiviado (13 a 204%). Utilizou-se o teste t de Student, para a análise estatística. Os resultados indicaram que, para a taxa máxima, o efluente do módulo receptor apresentou concentrações 1,8; 2,0; e 9,0 vezes superiores ao testemunho, para fósforo, nitrogênio amoniacal e E. coli, respectivamente. Além disso, houve aumento de lodo sedimentado na lagoa anaeróbia receptora (3,5 vezes em relação à testemunho) e formação de escuma (0,4 m3 por mês). Entretanto, as interferências na operação e manutenção são de simples solução, pois esses resíduos podem ser destinados no próprio aterro e os padrões de lançamento em corpos hídricos não foram contrariados. Desta forma, as lagoas de estabilização que tratam lixividados apresentam-se como uma alternativa competitiva para a destinação dos LFTS, resguardadas as condições operacionais estudadas. Abstract The destination of septage has resulted in environmental and public health problems, due especially to the lack of adequate alternatives for its destination and of closer, more rigorous monitoring. The problem worsens in areas lacking sewage treatment plants, since the disposal in such systems has been the most widely used practice in the country. In this way, the current research aims to evaluate the effects of the sludge disposal in the performance, operation and maintenance of waste stabilization ponds that treat landfill leachate. The treatment system studied is composed by two modules of identical anaerobic ponds followed by facultative ponds. For six months, the receiver modul was submitted to different rates of volumetric sludge application by leachate (13 to 204%). Student's t test was used for statistics analysis. The results indicated that for the maximum rate, the receiver module effluent showed concentrations 1.8; 2.0; and 9.0 times higher than the control modul, phosphorus, ammonia nitrogen and E. coli, respectively. In addition, there was an increase in the sedimented sludge in the receiving anaerobic pond (3.5 times in relation to the control group) and scum formation (0.4 m3 per month). However, the interferences in the operation and maintenance have simple solutions, since these residues may be sorted in the landfill itself and the release patterns in water bodies were not thwarted. In this way, the stabilization ponds that treat leachate present a competitive alternative for the destination of septage, safeguarding all operating conditions studied.

A series of pilot scale freezing bed experiments were conducted to evaluate and model the freeze–thaw treatment of septic tank sludge (septage). Filtrate quality is similar to a low strength domestic wastewater and the sludge cake has a dry matter content of 25% with E. coli numbers below 2.0 × 106 CFU/g dry solids. Experimental results showed no impact of snow cover on bed performance in a region with moderate snowfall (1.3–1.6 m) as new layers of sludge effectively melted any accumulated snow; suggesting that it is not necessary to cover the bed or remove the snow in areas where sludge dosing exceeds snowfall. Both freezing and thawing processes were successfully modelled with readily available climatic data. Model output for North American climatic conditions indicates that the freezing bed technology can be widely applied throughout the northern United States and Alaska and most of Canada with the exception of coastal areas and southern Ontario.

Performance of a full-scale duckweed-covered treatment system in removing faecal bacteria is presented. The system consisted of three ponds in series and received septage from holding tanks. Inflow averaged between 36 m3 d−1 in the cold season and 60 m3 d−1 in the warm season, resulting in a total hydraulic retention time of 88 and 58 days, respectively. Duckweed (Lemna minor) colonized the ponds in the summer and continued to grow in the cold season. Due to the difficult harvesting process of the duckweed biomass, the investigation of the treatment efficiency was carried out without plant harvesting. The system was monitored for temperature, pH, oxygen, chlorophyll-a, Escherichia coli and Enterococci. Duckweed growth resulted in chlorophyll-a concentration reduction from 924 to 13 μg L−1, causing neutral and anoxic conditions in the pond water. A temperature effect was noticed on the E. coli decay coefficient with a decreasing trend along the treatment system. Enterococci always decayed less than E. coli. Differences on decay coefficients and removal efficiencies were not observed between the three ponds for both bacterial types. Effluent quality in terms of E. coli was 489 and 1377 cfu/100 mL, in the warm and the cold seasons, respectively, with average removals of 99.65 ± 1.46% and 99.33 ± 3.03%. Total Enterococci removal was 88.91 ± 23.1% in the warm season and 94.43 ± 24.45% in the cold season, resulting in mean effluent values of 1058 and 1404 cfu/100 mL, respectively. The seasonal differences in total removal efficiencies were insignificant for both bacterial types.

Environmental conditions and wastewater treatment performance in a full-scale duckweed pond system are presented. The treatment system consisted of three stabilization ponds in series and was fed with septage. Vacuum trucks pumped the septage from residential holding tanks and discharged it to the system daily. The inflow rates averaged 36 m3 d(-1) in the cold season and 60 m3 d(-1) in the warm season. Duckweed (Lemna minor) colonized the ponds in the warm months and survived during the cold season. Because of the difficult process for harvesting the duckweed biomass, the investigation of the treatment efficiency was carried out without plant harvesting. Samples were collected from the vacuum trucks and from the exit of each pond and were analysed for physicochemical and microbiological parameters over a period of 12 months. The results showed that the duckweed mat suppressed algal biomass, which in turn led to anoxic and neutral pond conditions. On an annual basis, the duckweed system sufficiently removed BOD5 (94%), NH4+ (72%) and E. coli (99.65%), with lower removal of TSS (63%) and Enterococci (91.76%). A slight increase (1.1%) was recorded for o-PO4(3-). Between the two sampling seasons, BOD5 and TSS removal efficiencies were higher in the cold season with the longer retention time. Similar removal values in the warm and the cold season were found for nutrients and bacteria. These findings indicate that BOD5 and TSS removals are less temperature-dependent at higher retention times, while ammonia nitrogen and bacterial removals are substantially influenced by temperature as well as retention time.

Sanitation systems have vast differences among the countries as well as among different regions within the country. In Sri Lanka, over 90% of buildings rely upon onsite sanitation systems and most popularly with water sealed latrines connected to septic tanks or cesspits, however, the sanitizing the septage or nightsoil is required further treatment before disposing of or reuse. The filled cesspits/septic tanks are simply emptied using the suction trucks by the local authorities. Since the septage is removed from the site, the whole system can be named as partial onsite sanitation system (POSS). The practical problems that POSS may lead to are discussed throughout the paper using two case studies in Sri Lanka. Methodology follows both quantitative and qualitative social research techniques such as structured interviews with operators, downstream community, and health and sanitary workers, and collecting data on influent and effluent characteristics. Quantitative data were analyzed and interpreted using descriptive statistics. This paper provides a description of the complex issues that may stem out of POSS and possible factors for the sustainability of such systems. It is found that community participation, knowledge on sanitation, and institutional commitment were required to sustain the system which were lacking in two cases studied. It is advisable to develop programs and strategies to build up the capacity of local authorities to manage the sanitation systems and even to raise the awareness of community for good care of the onsite components. Key words: Nightsoil; Partially onsite sanitation system; Sanitation; Septage; Septic tanks.DOI: 10.4038/tar.v22i2.2823Tropical Agricultural Research Vol. 22 (2): 144-153 (2011)

Septage is widely acknowledged as a major source of infectious pathogens while disposal of septage, and the operation and maintenance of septic tanks, is not regulated in many developing countries. Twenty untreated septage and septage sludge samples were taken from Can Tho City, Vietnam to examine their pathogen content, and indicator micro-organisms. Escherichia coli and Enterococcus spp. were detected in all samples, regardless of sludge storage time. Phages were detected in 80% of samples. Salmonella spp. were detected in 70% of the untreated septage and 60% of septage sludge samples. Concentrations of phages and bacteria tested in septage sludge after many years of tank storage were much higher than the expected levels. Helminth ova were present in 95% of untreated septage samples with an average of 450 ova l − 1 , and were detected in all septage sludge samples with an average of 16,000 ova l − 1 . Twelve varieties of helminth ova were identified. More helminth ova varieties in higher concentrations were found in septage than those reported from stool samples. The varieties' frequency ranged from 10% to 50% and Ascaris lumbricoides predominated. Results show that pathogens and indicator micro-organisms, especially helminth ova, accumulate in sludge. Thus helminth ova should be considered when septage sludge is treated and used for agriculture. Proper health protection measures must be applied for people handling septage.

Manufactured soil for landscaping purposes was produced by composting for 6 weeks (1) municipal green waste alone, (2) green waste amended with 25% v/v poultry manure, or (3) green waste immersed in, and then removed from, a mixture of liquid grease trap waste/septage. Composting temperatures increased most rapidly and reached highest values (78oC) in the grease trap/septage-amended green waste. In comparison with green waste alone, addition of poultry manure prolonged the period of elevated temperatures and increased the maximum temperature attained from 52oC to 61oC. Following composting, each of the materials was split into (1) 100% compost, (2) 80% compost plus 20% v/v soil, and (3) 70% compost plus 20% soil plus 10% coal fly ash. Addition of poultry manure or grease trap/septage to green waste prior to composting increased bulk density and reduced total porosity of the composted product. Addition of soil, or soil and ash, to composts increased bulk density, reduced total porosity, decreased percentage macropores, and increased percentage mesopores and available water-holding capacity. Bicarbonate-extractable P, exchangeable NH 4 + and NO 3 − , electrical conductivity (EC), soluble C, soluble C as a percentage of organic C, basal respiration, and metabolic quotient were all markedly greater in the grease trap/septage-amended than poultry manure-amended or green waste alone treatments. Values for extractable P and EC were considered large enough to be damaging to plant growth and germination index (GI) of watercress was less than 60% for all grease trap/septage composts. Extractable P and EC were also high, and GI was 100%.

Detection of optical brighteners by fluorometry combined with ultraviolet light (UV) exposure has been proposed as an inexpensive method for detection of human fecal contamination, but has received limited testing. This study evaluated the approach in southern California by applying it to a variety of detergents, sewage and septage samples from the region, as well as to natural stream water as a negative control. The concept of using UV exposure to differentiate fluorescence from natural organic matter proved valid, as the method produced no false positives. However, the method failed to detect half of the detergents tested in natural stream water at 5 microL/L, due to its conservative thresholds. This study identified a method modification that provides greater sensitivity by taking advantage of differences in the shape of photodecay curves between optical brighteners and natural organic matter. This method modification resulted in detection of all detergents, sewage at 1:10 dilution and septage at 1:100 dilution. Several caveats for its use remain, including our observation that the optical brightener signal degraded rapidly in strong sunlight. Additionally, there was low sensitivity for some environmentally friendly detergents, which does not present a problem on a community basis where a mix of detergents are used, but could be of concern for assessing septic inputs from individual homes. Still, the method is simple to employ in the field, yields rapid results and is useful as a low-cost initial screening tool.

Co-disposal of septic tank sludge had a positive effect on the municipal solid waste (MSW) stabilisation process in Bioreactor Landfill simulators. Co-disposal experiments were carried out using the Bioreactor Landfill approach aiming to solve the environmental problems caused by indiscriminate and inadequate disposal of MSW and especially of septic tank sludge. The simulator receiving septic tank sludge exhibited a 200 days shorter lag-phase as compared to the 350 days required by the control simulator to start the exponential biogas production. Additionally, the simulator with septic sludge apparently retained more moisture (>60% w/w), which enhanced the overall conversion of organic matter hence increasing the biogas production (0.60 m3 biogas kg(-1)VS(converted)) and removal efficiency of 60% for VS from the simulator. Alkaline pH values (pH>8.5) did not inhibit the biogas production; moreover it contributed to reduce partially the negative effects of NH(4)(+) (>2 g L(-1)) due to NH(3) volatilisation thus reducing the nitrogen content of the residues. Associated risks and hazards with septage disposal were practically eliminated as total coliform and faecal coliform contents were reduced by 99% and 100%, respectively at the end of the experiment. These results indicate that co-disposal has two direct benefits, including the safe and environmentally sound disposal of septic tank sludge and an improvement of the overall performance of the Bioreactor Landfill by increasing moisture retention and supplying a more acclimatised bacterial population.

Individual septic tanks are the most common means of on-site sanitation in Malaysia, but they result in a significant volume of septage. A two-staged vertical flow constructed wetlands (VFCWs) system for the treatment of septage was constructed and studied in Sarawak, Malaysia. Raw septage was treated in the first stage wetlands, and the resulting percolate was fed onto the second stage wetlands for further treatment. Here, the effects of a batch loading regime on the contaminant removal efficiency at the second stage wetlands, which included palm kernel shell within their filter substrate, are presented. The batch loading regime with pond:rest (P:R) period of 1:1, 2:2 and 3:3 (day:day) was studied. The improvement of the effluent redox condition was evident with P:R = 3:3, resulting in excellent organic matters (chemical oxygen demand and biochemical oxygen demand) and nitrogen reduction. The bed operated with P:R = 1:1 experienced constant clogging, with a water layer observed on the bed surface. For the P:R = 3:3 regime, the dissolved oxygen profile was not found to decay drastically after 24 hours of ponding, suggesting that the biodegradation mainly occurred during the first day. The study results indicate that a suitable application regime with an adequate rest period is important in VFCWs to ensure efficient operation.

During a 5-month summer period, samples of tertiary treated wastewater flowing in an extensive distribution system composed of storage tanks and pipes were collected at 2-week intervals, from 21 different sampling points, including the exit from the wastewater treatment plant (WWTP). The WWTP producing this effluent treated one of the most popular European tourist resorts on the north coast of the island of Crete, at the southernmost point of Greece. The average summer equivalent population treated by the plant exceeded 50,000, falling to under 5,000 in the winter. The samples were analyzed for total coliforms number (TC in cfu / 100 mL) and residual chlorine concentration (RCHL in mg/L). In almost 60% of the samples the TC number was so large that it could be safe to suggest that the WWTP and distribution system failed to reach the EPA standards for wastewater reuse for tree irrigation (faecal coliformsor = 200 cfu/100 mL and RCHL1 mg/L) due mainly to inflow and septage handling, above designed limits. The licensing operational and reuse standards were set in TCor = 500 cfu/100 mL, where 76% of the analyzed samples recorded larger values. It was also estimated that in 14% of the samples the wastewater quality failed to reach even the less strict WHO standards of FCor = 1.000 cfu/100 mL. When chlorination was properly adjusted the effluent quality was improved (last three sets of samplings for each collection point), helped by the WWTP inflow decrease. As a result the values recorded in all tanks and collectors were also improved. However, even then, the required licensing standards were randomly and barely achieved. This suggests that specific wastewater quality standard at the exit of a WWTP do not guarantee that the wastewater will still retain these characteristics at its final application point.

Constructed wetland ecotechnologies (CWEs) are a promising solution to effectively treat domestic wastewater in developing countries at low cost. This paper reports the findings of the effectiveness of sand media amended with woody biochar and two plants species (Melaleuca quinquenervia and Cymbopogon citratus) in removing biological oxygen demand (BOD5), suspended solids and coliforms. The experimental design consisted of 21 vertical flow (VF) mesocosms. There were seven media treatments using sand amended with varying proportions of biochar. During the first 8 months, the mesocosms were loaded with secondary clarified wastewater (SCW) then septage. The influent had a 4-day hydraulic retention time. Samples were monitored for BOD5, total suspended solids (TSS), total volatile solids (TVS), total coliforms and faecal coliforms. In the first 8 months, there were no significant performance differences between media treatments in the outflow concentrations of BOD5, TSS and TVS. The significant differences occurred during the last 3 months; using septage with biochar additions performed better than pure sand. For coliforms, the significant differences occurred after 6 months. In conclusion, the addition of biochar was not effective for SCW. The VF mesocosms system proved to be more effective in removing BOD5, TSS, TVS and coliforms when septage was loaded into the media.

This study investigated the performance of sludge drying reed beds (SDRB) at full- and pilot-scale treating sludge from septic tanks in the city of Belo Horizonte, Brazil. The treatment units, planted with Cynodon spp., were based on an adaptation of the first-stage of the French vertical-flow constructed wetland, originally developed for treating sewage. Two different operational phases were investigated; in the first one, the full-scale unit was used together with six pilot-scale columns in order to test different feeding strategies. For the second phase, only the full-scale unit was used, including a recirculation of the filtered effluent (percolate) to one of the units of the French vertical wetland. Sludge application was done once a week emptying a full truck, during 25 weeks. The sludge was predominantly diluted, leading to low solids loading rates (median values of 18 kgTS m−2year−1). Chemical oxygen demand removal efficiency in the full-scale unit was reasonable (median of 71%), but the total solids removal was only moderate (median of 44%) in the full-scale unit without recirculation. Recirculation did not bring substantial improvements in the overall performance. The other loading conditions implemented in the pilot columns also did not show statistically different performances.

Since the early 1980s, investigations by health departments of eight counties in southern New Jersey, by the NJ Department of Environmental Protection (NJDEP), and subsequently by the US Geological Survey (USGS), have shown that Hg concentrations in water tapped by about 600 domestic wells exceed the maximum contaminant level (MCL) of 2 μg/L. The wells are finished in the areally extensive unconfined Kirkwood-Cohansey aquifer system of New Jersey's Coastal Plain; background concentrations of Hg in water from this system are < 0.01 μg/L. Evidence of contributions from point sources of Hg, such as landfills or commercial and industrial hazardous-waste sites, is lacking. During 1996–2003, the USGS collected water samples from 203 domestic, irrigation, observation, and production wells using ultraclean techniques; septage, leach-field effluent, soils, and aquifer sediments also were sampled. Elevated concentrations of NH4, B, Cl, NO3, and Na and presence of surfactants in domestic-well water indicate that septic-system effluent can affect water quality in unsewered residential areas, but neither septage nor effluent appears to be a major Hg source. Detections of hydrogen sulfide in ground water at a residential area indicate localized reducing conditions; undetectable SO4 concentrations in water from other residential areas indicate that reducing conditions, which could be conducive to Hg methylation, may be common locally. Volatile organic compounds (VOCs), mostly chlorinated solvents, also are found in ground water at the affected areas, but statistically significant associations between presence of Hg and VOCs were absent for most areas evaluated. Hg concentrations are lower in some filtered water samples than in paired unfiltered samples, likely indicating that some Hg is associated with particles or colloids. The source of colloids may be soils, which, when undisturbed, contain higher concentrations of Hg than do disturbed soils and aquifer sediments. Soil disturbance during residential development and inputs from septic systems are hypothesized to mobilize Hg from soils to ground water.

The coverage of sewage works is still limited in urban areas of developing counties, although attempts have been made to develop sewage works in those areas. Present household-wastewater treatment (sanitation) facilities such as septic tanks should be utilized until sewage works with adequate wastewater treatment facilities will cover the areas. For the effective use of existing facilities, those should be managed correctly. It has been, however, stated that most of the facilities are not in appropriate conditions. The present household-wastewater management in Hanoi city of Vietnam was investigated by interview with questioners and some keys to utilize present facilities, especially septic tanks, were shown in this study. It was found that 96.5% of flush-toilet holders in Hanoi had septic tanks. Septic tanks are considered to play a major role in household wastewater management in Hanoi city. Although regular removals of septage are one of the fundamental matters to utilize septic tanks, the 95.2% of septic-tank holders had no experience of septage removals. The proper removal of septage is considered to be a crucial issue for utilization of present household-wastewater treatment facilities.

This paper presents the purification performance of 20 wastewater treatment plants with vertical reed bed filters (Macrophyltres®), built between 1998 and 2003 by SAS Voisin, for communities of between 150 and 1400 PE. The first stage vertical reed bed (directly fed with raw wastewater by intermittent feeding) achieved high removal of SS, BOD and COD (mean respectively 96%, 98%, 92%). The second stage permitted compliance easily with effluent standards (SS < 15 mg/l, BOD < 15 mg/l, COD < 90 mg/l and mean TKN < 10 mg/l). Performance was not significantly influenced by variations of organic and hydraulic load, nor by seasonal variations. Rigorous operation and maintenance were required to obtain optimal performances. Another application of vertical reed beds is the treatment of septage (sludge from individual septic tanks). The results obtained on two sites operating for 2 and 3 years are presented. The first site achieved complete treatment of septage (solid and liquid fraction), the second permitted a pre-treatment for co-treatment of percolate with wastewater.

In tropical regions, where most of the developing countries are located, septic tanks and other onsite sanitation systems are the predominant form of storage and pre-treatment of excreta and wastewater, generating septage and other types of sludges. The septage is disposed of untreated, mainly due to lack of affordable treatment options. This study presents lessons that have been learned from the operation of pilot-scale constructed wetlands (CWs) for septage treatment since 1997. The experiments have been conducted by using three CW units planted with narrow-leave cattails (Typha augustifolia) and operating in a vertical-flow mode. Based on the experimental results, it can be suggested that the optimum solids loading rate be 250 kg TS/m2 yr and 6-day percolate impoundment. At these operational conditions, the removal efficiencies of CW units treating septage at the range of 80–96% for COD, TS and TKN were achieved. The biosolid accumulated on the CW units to a depth of 80 cm has never been removed during 7 years of operation, but bed permeability remained unimpaired. The biosolid contains viable helminth eggs below critical limit of sludge quality standards for agricultural use. Subject to local conditions, the suggested operational criteria should be reassessed at the full-scale implementation.

Farms that once spread only manures are now also applying sewage biosolids (sludge) and/or other wastes such as those from food processing. The objective of this study was to monitor environmental impacts at a dairy farm applying these materials. Fields were selected representing recent waste applications of manure (M1, M2), sewage biosolids (B1, B2), or fertilizer only control (F1, F2), although most fields had historical biosolids applications. Fields representing each treatment were not experimental replicates because of varying applications and soil characteristics. Septage and food processing wastes were also applied. Soil percolates were collected with wick lysimeters. Runoff was sampled at seven stream sites. Test field soils and alfalfa (Medicago sativa) were analyzed for trace elements. Cumulative trace metal loadings were low, at most only 1 percent of USEPA Part 503 limits. Surface soil enrichment was most evident for Mo, P, and S. Alfalfa tissue showed no trends of concern. The B2 site had the greatest percolate concentrations for 6 of 13 elements. Percolate Cu was somewhat elevated at Sites M1, M2, B2, and Fl. Percolate sodium was elevated on all M and B fields and sulfur was greatest at M2, B1, and B2. Soluble orthophosphate correlated with stream discharge during intensive monitoring of Stream Sites S1 (fertilizer) and S2 (biosolids). Peaks in S2 streamwater Mo lagged large runoff events by five days. Total streamwater export of Cu, Na, Mo, and soluble P were greater from the S2 biosolids subwatershed than from the S1 fertilizer subwatershed. Percolate concentrations exceeded corresponding streamwater concentrations in most cases.

In pond and wetland systems for wastewater treatment, plants are often thought to enhance the removal of ammonium and nitrogen through the activities of root-associated bacteria. In this study, we examined the role of plant roots in an aerated pond system with floating plants designed to treat high-strength septage wastewater. We performed both laboratory and full-scale experiments to test the effect of different plant root to septage ratios on nitrification and denitrification, and measured the abundances of nitrifying bacteria associated with roots and septage particulates. Root-associated nitrifying bacteria did not play a significant role in ammonium and total nitrogen removal. Investigations of nitrifier populations showed that only 10% were associated with water hyacinth [Eichhornia crassipes (Mart.) Solms] roots (at standard facility plant densities equivalent to 2.2 wet g roots L(-1) septage); instead, nitrifiers were found almost entirely (90%) associated with suspended septage particulates. The role of root-associated nitrifiers in nitrification was examined in laboratory batch experiments where high plant root concentrations (7.4 wet g L(-1), representing a 38% net increase in total nitrifier populations over plant-free controls) yielded a corresponding increase (55%) in the non-substrate-limited nitrification rate (V(max)). However, within the full-scale septage-treating pond system, nitrification and denitrification rates remained unchanged when plant root concentrations were increased to 7.1 g roots L(-1) (achieved by increasing the surface area available for plants while maintaining the same tank volume). Under normal facility operating conditions, nitrification was limited by ammonium concentration, not nitrifier availability. Maximizing plant root concentrations was found to be an inefficient mechanism for increasing nitrification in organic particulate-rich wastewaters such as septage.

Organic loads have been significantly reduced in nightsoil plants along with the employment of sewage treatment plants. Nightsoil consisting of 10% septage and showing higher ratios of alkalinity and carbon to nitrogen helped nitrification and denitrification for those combined plants with weak piggery waste. However, alkalinity and carbon addition was necessary with the weak nightsoil consisting of 80% septage when the combined influent was less than 21 g/L COD. The piggery waste could be applied at a rate of 0.5 kgTKN/oxic m3/d, but the organic load should be limited to 0.7 kgCOD/m3/d with strong piggery waste during summer in order not to exceed the reactor temperature higher than 35°C.

Maintenance of the more than 24 million septic tanks in the U.S. requires removal and disposal of septage. Disposal options include application to agricultural lands where the nutrients and organic matter can provide soil benefits. However, pathogens and contaminants are also contained in septage. An extensive search turned up very few data on septage quality, and those reveal high variability. The data used by the U.S. Environmental Protection Agency (EPA) in developing regulations had the lowest metal concentrations among the nine data sets that could be compared. Based on these data, EPA assumed that septage could be applied to agricultural land for more than 100 applications before reaching unacceptable cumulative loading of metals. They thus did not establish federal standards for metals in septage, and no monitoring is required under federal rules governing septage disposal. Analysis of the nine data sets we found showed that field site life would be reached in less than 100 applications for most septage and cumulative loading limits established by EPA for sewage sludges will be exceeded in 16 applications for some septage as opposed to the 100 application estimate used by EPA. Determination of acceptable cumulative loading depends on numerous technical and policy considerations. All septage sources reached the more restrictive loading limits such as those established by the New York State Department of Environmental Conservation (NYSDEC) and the recommendations in Cornell publications in less than 100 applications. In one case the cumulative limit for copper was exceeded in a single application. These findings suggest additional data are needed on septage quality and that the federal and state agencies responsible for regulating application of septage to agricultural land should reassess their standards.

The performance of duckweed and algal systems in removing fecal bacteria, organic matter, and nutrients was evaluated in three full-scale ponds operating in series. Trucks collected septage from holding tanks and discharged it into the system, daily. The inflow rates varied between the warm and the cold season. Duckweed and algae naturally colonized the ponds in two successive periods of 10 and 13 months, respectively. Environmental conditions were determined at various pond depths. Without harvesting, the duckweed system was neutral and anoxic. Alkaline and oversaturation conditions were observed in the algal system. The overall removals of 5-day biochemical oxygen demand, total suspended solids, total nitrogen removal, and orthophosphate (ortho-PO4(3-)) ranged from 94 to 97, 62 to 84, 68 to 74, and 0 to 26%, respectively. The E. coli and enterococci reductions varied between 2.2 to 3.0 and 1.1 to 1.4 log units, respectively. The upper values were always associated with the algal system.

This paper deals with the characteristics and treatment options of septage. The objective of the paper is to evaluate the effects of co-treatment of 50 MLD of septage in a sewage treatment pond system. The treatment efficiency of the pond system for BOD5 and Fecal Coliform (FC) has been estimated using a first order kinetics model. The model has predicted that the treatment pond system has a maximum capacity of 8.5 MLD and will have a reserve of 28.3% of its total capacity even after the proposed addition of 50 MLD of septage. Separation of oil and grease from septage prior to discharge into the pond system is recommended.

We examined the factors controlling organic carbon (C) cycling and its control of nitrogen (N) removal via denitrification in an aerated artificial wetland treating highly concentrated wastewater to nutrient-removal standards. Processing of organic material by the septage-treating wetland affected the biological reactivity (half-life, or t1/2) of organic C pools through microbial degradation and gravity fractionation of the influent septage. Primary sedimentation fractionated the initial septage material (t1/2 = 8.4d) into recalcitrant waste solids (t1/2 = 16.7d) and highly labile supernatant (t1/2 = 5.0d), allowing this reactive fraction to be further degraded during treatment in aerobic wetland tanks until a less labile material (t1/2 = 7.3d) remained. Organic C contributions from in situ fixation by nitrifying bacteria or algae in these tanks were small, about 1% of the C degradation rate. In the aerated tanks, denitrification was correlated with particulate organic C loading rates, although the average C required (0.35 mg C L(-1)h(-1)) to support denitrification was only 12% of the total C respiration rate (2.9 mg C L(-1)h(-1)). Additions of plant litter (2.5g C L(-1)) to the aerated tanks under normal operating conditions doubled denitrification rates to 0.58 mg N L(-1)h(-1), and reduced effluent nitrate levels by half, from 12.7 to 6.4 mg N L(-1). However, C degradation within the plant litter (0.15mg C L(-1)h(-1)) was sufficient to have accounted for only 35% of the additional denitrification. Evidence from laboratory and full-scale plant litter additions as well as process monitoring indicates that the stimulation of denitrification is due to the respiration-driven formation of anaerobic microsites within particulate organic C. In this aerated highly C-loaded septage-treating wetland, anaerobic microsite, rather than C substrate availability limits denitrification.

A one year study was carried out in a waste stabilization ponds system where septage and sewage are cotreated. The system consists of two septage ponds which operate alternately followed by two ponds in series which receive the combined effluent. The septage ponds also act as evaporation ponds for the accumulated sludge. The monitoring program was divided in two phases. The results of the first phase indicate that the effluent of septage ponds has an adequate quality to be discharged into the waste stabilization ponds designed to treat sewage and that is possible to use the septage ponds to dry the accumulated sludge. Further investigation is needed to find suitable post-treatment of the sludge in order to use it in agriculture.

The goal of this study was to characterize microbial communities in anaerobic batch digesters treating different representative organic sources (sewage sludge, food waste, septage). Among the digesters, the anaerobic digester of food waste had the highest methanogen density, producing a peak value methane yield of 813.2 mL CH 4 /g VS. In all the digesters, acetoclastic Methanosarcinales and hydrogenotrophic Methanomicrobiales were the most dominant methanogen groups, but their proportion among the methanogens varied depending on the organic sources. The bacteria community in the anaerobic digestion (AD) of food waste and septage was distinctly different from that found in the AD of sewage sludge (primary sludge and waste activated sludge). Shifts in both bacterial and archaeal community structures could be related to differences in chemical properties, production, and accumulation of intermediates digested from organic wastes having different characteristics. These findings could prove useful in optimizing the microbial community to enhance AD process treating organic wastes.

Over 1.7 million Virginians rely on private water sources to provide household water. The heaviest reliance on these systems occurs in rural areas, which are often underserved with respect to available financial resources and access to environmental health education. This study aimed to identify potential associations between concentrations of fecal indicator bacteria (FIB) (coliforms, Escherichia coli) in over 800 samples collected at the point-of-use from homes with private water supply systems and homeowner-provided demographic data (household income and education). Of the 828 samples tested, 349 (42%) of samples tested positive for total coliform and 55 (6.6%) tested positive for E. coli. Source tracking efforts targeting optical brightener concentrations via fluorometry and the presence of a human-specific Bacteroides marker via quantitative real-time polymerase chain reaction (qPCR) suggest possible contamination from human septage in over 20 samples. Statistical methods implied that household income has an association with the proportion of samples positive for total coliform, though the relationship between education level and FIB is less clear. Further exploration of links between demographic data and private water quality will be helpful in building effective strategies to improve rural drinking water quality.

Active pharmaceutical ingredients (APIs) can enter the natural environment during manufacture, use and/or disposal, and consequently public concern about their potential adverse impacts in the environment is growing. Despite the bulk of the human population living in Asia and Africa (mostly in low- or middle-income countries), limited work relating to research, development and regulations on APIs in the environment have so far been conducted in these regions. Also, the API manufacturing sector is gradually shifting to countries with lower production costs. This paper focuses mainly on APIs for human consumption and highlights key differences between the low-, middle- and high-income countries, covering factors such as population and demographics, manufacture, prescriptions, treatment, disposal and reuse of waste and wastewater. The striking differences in populations (both human and animal), urbanization, sewer connectivity and other factors have revealed that the environmental compartments receiving the bulk of API residues differ markedly between low- and high-income countries. High sewer connectivity in developed countries allows capture and treatment of the waste stream (point-source). However, in many low- or middle-income countries, sewerage connectivity is generally low and in some areas waste is collected predominantly in septic systems. Consequently, the diffuse-source impact, such as on groundwater from leaking septic systems or on land due to disposal of raw sewage or septage, may be of greater concern. A screening level assessment of potential burdens of APIs in urban and rural environments of countries representing low- and middle-income as well as high-income has been made. Implications for ecological risks of APIs used by humans in lower income countries are discussed., Facultad de Ciencias Exactas

A destinação dos Resíduos de Fossa e Tanque Séptico (RFTS) tem resultado em problemas ambientais e de saúde pública, devido principalmente à falta de alternativas adequadas para a destinação, e de fiscalização mais rigorosa. O problema se agrava em municípios desprovidos de estações de tratamento de esgoto, já que a disposição nesses sistemas tem sido a prática mais utilizada no país. Neste contexto, a presente pesquisa teve por finalidade avaliar as possíveis interferências da disposição dos RFTS no desempenho, operação e manutenção no sistema de tratamento de lixiviados do Aterro Sanitário de Anápolis (GO). Também foi realizada a caracterização dos RFTS do município, através da análise de doze amostras compostas, cada uma proveniente de cinco caminhões limpa-fossas. Avaliou-se o sistema composto por dois módulos idênticos, sendo um testemunho e outro receptor de RFTS. Este foi submetido, de forma crescente, a diferentes Taxas de Aplicação Volumétrica (TAV) de RFTS, iniciando com TAV de 13%, até chegar a TAV de 204%. O estudo foi executado e os parâmetros físico-químicos e microbiológicos (DBO, DQO, pH, OG, fósforo total, nitrogênio amoniacal, sólidos suspensos, sólidos sedimentáveis e Escherichia coli) de amostras simples do afluente e efluente das lagoas anaeróbias e facultativas de ambos módulos foram analisados. Nas lagoas anaeróbias verificaram-se os possíveis impactos na manutenção e operação do sistema, através da medição da altura do lodo sedimentado no fundo da lagoa e da quantificação da escuma formada em sua superfície. Nas lagoas facultativas realizou-se o levantamento da comunidade fitoplanctônica, visando identificar possíveis interferências da codisposição de RFTS na riqueza e abundância de algas e cianobactérias. Os dados obtidos foram tratados estatisticamente, através do teste t the Student, e os resultados indicaram que até a TAV de 18% não houve alterações significativas na qualidade do lixiviado tratado (efluente das lagoas de estabilização). A partir da TAV de 35% detectou-se diferença significativa na concentração de E. coli e nitrogênio amoniacal no efluente tratado (p

This publication showcases a compilation of project briefs culled from case studies of good practices, new approaches, and working models on sanitation and wastewater management from di erent countries. The project briefs demonstrate solution options from which useful lessons can be derived. Not only do they illustrate how sanitation and wastewater management challenges can be addressed, the project briefs also aim to inspire replication and show opportunities for actions and investments. Given the more complex water resource and health challenges in many parts of the world, it is time to engage in a rational analysis of all possible management strategies, learn from others’ experiences, apply innovative approaches, and tap potential markets.

Surface water pollution is one of the serious environmental problems in urban centers in Nepal due to the discharge of untreated wastewater into the river-system, turning them into open sewers. Wastewater treatment plants are almost non-existent in the country except for a few in the Kathmandu Valley and even these are not functioning well. Successful implementation of a few constructed wetland systems within the past three years has attracted attention to this promising technology. A two-staged subsurface flow constructed wetland for hospital wastewater treatment and constructed wetlands for treatment of greywater and septage is now becoming a demonstration site of constructed wetland systems in Nepal. Beside these systems, five constructed wetlands have already been designed and some are under construction for the treatment of leachate and septage in Pokhara municipality, wastewater in Kathmandu University, two hospitals and a school. This paper discusses the present condition and treatment performance of constructed wetlands that are now in operation. Furthermore, the concept of the treatment wetlands under construction is also described here. With the present experience, several recommendations are pointed out for the promotion of this technology in the developing countries.

In the present study, the effect of the leachate from the major landfill in northern Jordan, El-Akader on the ground-water was investigated. Various physical and chemical parameters were estimated, this includes pH, total hardness, electrical conductivity, and total dissolved solids for the physical parameters. The chemical parameters included are major cations, Ca+2, Mg+2, Na+, and K+. Major anions, HCO−3, NO−23, Cl−, and SO−24, major ions PO−34, and heavy metals, Pb, Fe, Mn, Cd, and Zn. The landfill leachate is a result of both solid waste and septage waste. El-Akader dump site receive both solid waste and waste-water, the average septage volume received at El-Akader site is 2305 m3day−1, and almost 217 tankers with the capacity of 11 m3discharge their loads at El-Akader site. The total volume of solid waste dumped into the site was estimated to about 400 tonnes day−1. An area almost 6 km from the landfill site following the ground-water flow direction towards the north-eastern wards was covered. The results showed that the landfill leachates constitute a serious threat to the local aquifers.

Septage disposal presents technical difficulties due to its high concentrations of solids and nutrients. Many existing treatment options create excessive waste solids or fail to remove nutrients, which, upon discharge, impact groundwater and aquatic systems. This study evaluated nitrogen removal in an ecologically engineered wastewater treatment system (the Solar Aquatic System™ [SAS]) that combines aeration and activated solids recycling with aquatic and constructed wetlands treatment components. A septage-treating SAS in coastal Massachusetts, USA, produced an effluent of 113 mg/l chemical oxygen demand, 16 mg/l total suspended solids (TSS), 0.56 mg/l ammonium nitrogen, 6.1 mg/l total nitrogen and 1.5 mg/l total phosphorus. Waste solids production was low at 0.81 g/g influent TSS, including harvested plant biomass. Primary treatment was by biological oxidation with activated solids, followed by gravity clarification. Further oxidation and ammonium removal occurred in planted aerated aquatic tanks enclosed in a greenhouse, followed by secondary gravity clarification. Nitrogen removal in the aquatic tanks was limited by denitrification, which was limited by the availability of anaerobic microsites. Mineralization of particulate organic nitrogen, followed by nitrification and denitrification, occurred simultaneously during primary treatment and in the aquatic tanks. Final solids polishing and denitrification occurred in a constructed wetland. Although 88% of the influent nitrogen was removed during primary treatment, further treatment in the aquatic tanks and wetlands was required to reduce effluent nitrogen to tertiary standards. Nitrogen removal in the whole system was primarily by sedimentation of waste solids, accounting for 57.6% of the influent nitrogen, followed by denitrification, at 40.9%. Direct uptake of nitrogen by plants was insignificant, at 0.5%. 1.0% of the total influent nitrogen left the facility in the effluent water. The SAS has the capability to treat septage to tertiary standards with low solids production in small, decentralized facilities.