Explore the vast range of titles available.

Coastal marine ecosystems face a host of pressures from both offshore and land-based human activity. Research on terrestrial threats to coastal ecosystems has primarily focused on agricultural runoff, specifically showcasing how fertilizers and livestock waste create coastal eutrophication, harmful algae blooms, or hypoxic or anoxic zones. These impacts not only harm coastal species and ecosystems but also impact human health and economic activities. Few studies have assessed impacts of human wastewater on coastal ecosystems and community health. As such, we lack a comprehensive, fine-resolution, global assessment of human sewage inputs that captures both pathogens and nutrient flows to coastal waters and the potential impacts on coastal ecosystems. To address this gap, we use a new high-resolution geospatial model to measure and map nitrogen (N) and pathogen—fecal indicator organisms (FIO)—inputs from human sewage for ~135,000 watersheds globally. Because solutions depend on the source, we separate nitrogen and pathogen inputs from sewer, septic, and direct inputs. Our model indicates that wastewater adds 6.2Tg nitrogen into coastal waters, which is approximately 40% of total nitrogen from agriculture. Of total wastewater N, 63% (3.9Tg N) comes from sewered systems, 5% (0.3Tg N) from septic, and 32% (2.0Tg N) from direct input. We find that just 25 watersheds contribute nearly half of all wastewater N, but wastewater impacts most coastlines globally, with sewered, septic, and untreated wastewater inputs varying greatly across watersheds and by country. Importantly, model results find that 58% of coral and 88% of seagrass beds are exposed to wastewater N input. Across watersheds, N and FIO inputs are generally correlated. However, our model identifies important fine-grained spatial heterogeneity that highlight potential tradeoffs and synergies essential for management actions. Reducing impacts of nitrogen and pathogens on coastal ecosystems requires a greater focus on where wastewater inputs vary across the planet. Researchers and practitioners can also overlay these global, high resolution, wastewater input maps with maps describing the distribution of habitats and species, including humans, to determine the where the impacts of wastewater pressures are highest. This will help prioritize conservation efforts.Without such information, coastal ecosystems and the human communities that depend on them will remain imperiled.

Individual septic tanks (ISTs) are on-site systems for treating domestic wastewater, which can produce greenhouse gases (GHGs), mainly methane and nitrous oxide. The decomposition of organic material by microbes in human waste contributes to methane generation, especially in tanks that are not desludged as often as recommended—usually every two years. Traditional data collection methods often struggle to accurately capture waste characteristics due to high costs and limited knowledge among respondents, leading to data inconsistencies. This research studied two ISTs, each over 30 years old, to estimate emissions of methane and nitrous oxide from direct and indirect sources. Using the 2006 IPCC guidelines and primary wastewater data, emissions were calculated for these tanks, serving as benchmarks for similar setups. In Malaysia, where over a million ISTs are in use, these are the predominant wastewater treatment option for households. Findings revealed that ISTs with an average Biochemical Oxygen Demand (BOD) of 151 mg/L released more methane compared to those with a BOD of 142 mg/L, largely due to anaerobic treatment processes. GHG emissions, measured on a per capita basis, were 43.2 and 46.0 grams per person per day for each system, with direct treatment processes contributing more to emissions than indirect processes from treated wastewater. This data serves as a foundation for estimating GHG emissions from on-site septic systems, enhancing our understanding of their Global Warming Potential (GWP).

The current increase in population continues to encourage intensive development, especially residential development. Continuous development has an impact on people’s lives, especially in the management of domestic wastewater. People generally use septic tanks to manage household domestic wastewater, but this often does not comply with the provisions stipulated in Standar Nasional Indonesia (SNI), so it has the potential to pollute shallow groundwater. This simulation was carried out in a 100 cm x 100 cm x 40 cm glass box. The research aims to determine the distribution distance, travel time, and flow rate of septic tank wastewater spreading inside the glass box. The distribution simulation is carried out at scale testing between laboratory and existing conditions of 1:10. The results showed that contaminants concentration decreased through the soil, with a removal efficiency of 75.6% for E. coli and 65.9% for Ammonia. The simulation results showed that horizontal spread in the glass box at a distance of 80 cm required a travel time of 565 minutes (9 hours and 25 minutes) with wastewater spread speed/flow rate of 7,2 x 10 −3 litres per minute. This test concluded that the concentration of Escherichia coli and ammonia at a distance of 8 m from the source of wastewater spread does not meet the quality standard as a clean water resource.

Engineered nanomaterials (ENMs) are commonly incorporated into food and consumer applications to enhance a specific product aspect (i.e., optical properties). Life cycle analyses revealed ENMs can be released from products during usage and reach wastewater treatment plants (WWTPs), with titanium dioxide (TiO2) accounting for a large fraction. As such, food grade (FG) TiO2, a more common form of TiO2 in wastewater, was used in this study. Nanomaterials in WWTPs have been well characterized, although the problematic septic system has been neglected. Elution and bioaccumulation of TiO2 ENMs from WTTPs in downriver sediments and microorganisms has been observed; however, little is known about mechanisms governing the elution of FG TiO2 from the septic drainage system. This study characterized the transport behavior and mechanisms of FG TiO2 particles in porous media conditions after septic waste treatment. FG and industrial grade (IG) TiO2 (more commonly studied) were introduced to septic tank effluent and low-ionic strength electrolyte solutions prior to column transport experiments. Results indicate that FG TiO2 aggregate size (200–400 nm) remained consistent across solutions. Additionally, elution of FG and IG TiO2 was greatest in septic effluent at the higher nanoparticle concentration (100 ppm). FG TiO2 was well retained at the low (2 ppm) concentration in septic effluent, suggesting that particles that escape the septic system may still be retained in drainage field before reaching the groundwater system, although eluted particles are highly stabilized. Findings provide valuable insight into the significance of the solution environment at mediating differences observed between uniquely engineered nanomaterials.

The article discusses the environmental and economic aspects of faecal sludge management in an individual residential sector, proposes approaches to solving the problem, discusses findings in improving the effectiveness of the biodegradation rate of faecal sludge and domestic wastewater in a septic tank, and evaluates the using adequacy of biological additives for accelerating faecal sludge biodegradation.

The aim of the work was to analyze the effi ciency and reliability of pollutants removal (total suspended solids – TSS, BOD5, COD) in a collective wastewater treatment plant with activated sludge and hydroponic lagoon during its long term operation. The tested object was designed to treat wastewater in flowing through the sewerage system and wastewater delivered by the septic truck. The projected capacity of the treatment plant was 1200 m3∙d-1. The technological system for wastewater treatment consisted of a mechanical part, a flowing biological reactor working according to the BARDENPHO process, a secondary settling tank and a hydroponic lagoon. The efficiency and reliability of pollutants removal in the analyzed treatment plant were assessed on the basis of the data concerning influent and effluent wastewater collected during the years 2011–2018. On the basis of the measurements results, there were determined characteristic values of the selected pollution indicators in wastewater and the average efficiency of pollutants removal. The technological reliability of the wastewater treatment plant was assessed for the basic pollution parameters (BOD5, COD, TSS) in accordance with the elements of the Weibull’s reliability theory, with regard to normative values of the indicators specified in the Regulation of the Minister of Environment. The analysis was carried out using the Statistica 13.1 software. It was proved that in the wastewater treatment plant with an activated sludge and hydroponic lagoon the level of organic pollutants removal expressed by BOD5 was on average 99.5%, COD – 98.1% and TSS – 99.4%. The technological reliability of the system was 100% in terms of the removal of pollutants from the basic group, which means that during the long term operation (8 years) it provided failure-free operation and guaranteed the fulfillment of the requirements that can be found in the Polish law regulations concerning the analyzed pollutants.

Domestic wastewater treatment unit consisted of a single chamber septic tank and Subsurface Flow Constructed Wetland (SFCW) was built in Yogyakarta, Indonesia. SFCW played a significant role as secondary treatment of septic tank effluent. This study aimed to analyze the soil nitrate and its distribution in sand layer of SFCW. The SFCW had a depth of 0.2 m of coral and sand layers with two leach pipes that were installed in the depth of 0.3 m along the garden and planted with chili (Capsicum frutescens). Soil nitrate content of SFCW and plant growth were analyzed for 8 weeks of observation. Soil samples were taken in different direction, both vertical and horizontal. In vertical direction, samples were taken with three different depth (10, 15, and 20 cm) from the surface. In horizontal direction samples were taken with three different distance from outlet pipe. Soil nitrate obtained in vertical direction was significantly different (P<0.005) with soil nitrate at the depth of 20 cm was higher than 15 cm and 10 cm. However, the soil nitrate obtained in horizontal direction was not significant (P>0.05). The soil nitrate has positive correlation with plant growth, the higher soil nitrate will increase the plant growth.

Odor nuisance and sulfide corrosion in sewers carrying septic wastewater are accelerated at points of turbulence such as drops in manholes, but accurate methods or empirical expressions to evaluate the gas stripping rate at those particular sites are still missing. With the aim of improving the current knowledge on the influence of free-fall drops on the release of hydrogen sulfide gas, an experimental set-up was built allowing different free-fall drops heights and flows. Three types of experiments were carried out: reaeration tests without sulfide; sulfide oxidation tests; and hydrogen sulfide release tests. With the increase of the free-fall drop height or of the flow, a higher rate of air-to-water mass oxygen transfer was observed. Results regarding sulfide oxidation tests with reaeration through the free-fall have shown that the oxidation rate was correlated with flow. In the hydrogen sulfide release tests, the maximum concentration in the atmosphere reached 500 ppm. Results also showed that increasing the flow rate decreased the time at which the maximum concentrations in the atmosphere were observed.

Soil dispersion due to salinization is an important concern associated with the land application of saline wastes. When residual brine is transferred to septic systems, dispersion of sludge can lead to complications, as well. This study investigated sludge and microbial population response of septic wastewater during residual saline application. Salinity concentration up to 10 ppt (‰) was included, within the range of residual saline waters in the region. The dominant salt cations by order of decreasing concentration were Na, Ca, and Mg. The initial heterotrophic microbial population was lowest for all control and treatments in the log 4.5–4.8 cfu mL −1 range. A regrowth period followed towards the end of the experiment commonly reaching log 6 cfu mL −1 . UV absorbance was used to quantify dispersion of solids and treatments produced statistically significant differences in absorbance. This work shows the importance of considering the consequences of saline application to waste.

Salinity of water sources is a worldwide problem. Desalinization technologies improve the water quality but produce a highly saline residual waste. One proposed method of disposal is transfer into septic systems. We investigated the microbiological response of septic wastewater to saline backwash. Salinity concentration within the range of residual saline waters in the region was included. Diversity of bacteria and fungi was determined using 454-pyrosequencing. Treatments shared a very similar distribution and richness of bacterial and fungal diversity. Fungal diversity was represented mostly by Dothideomycetes members; Pezizomycetes were inhibited with treatment. Operational taxonomic units from Gammaproteobacteria were common throughout treatments and wastewater control, but increased with treatment. Bacterial populations underwent selection with salinity treatment, likely a statistically significant effect ( p  = 0.06). The study shows that microbial populations in wastewater are an important aspect to consider when introducing brackish waste into waste stream even in these short-term field conditions.