Wetland Technology Research Articles

Alleviating Water Scarcity in Rural Arid Areas through Grey Water Treatment and Reuse: Palestine as a Case Study

Conventional water sources in Palestine are vulnerable and scarce. Among potential alternative non-conventional water sources is greywater which comprises 50–80% of residential wastewater. In this paper the long and short term impacts assessment of six onsite greywater treatment plants, GWTPs using constructed wetland technology was conducted. The constructed wetland system were constructed by National Agricultural Research Committees, NARC and International Center for Agricultural Research in the Dry Areas, ICARDA in Northern West Bank to disseminate the safe uses of the treated greywater. Performance indicators were used for assessing the quality and efficiency of the execution of six treated greywater reuse stations in Jenin and Tubas governorates. Effluent from the six plants was reused in nine home gardens for fruit tree (citrus and olive) and fodder (sorghum) plantations. A field survey was designed and conducted for reuse beneficiaries. The short term indicator included greywater quality parameter before and after treatment during the period from June and July 2015. pH , TDS, Na+ ,Ca2+ ,Cl- ,BOD ,PO42+ and SO42-fall within the Palestinian standard for treated wastewater (2012). The average water quality was: pH 7.5, TDS 1024.27, Na 128.2, Ca 65.6, Cl 224, Mg 288.3,NO-3 77.8 and COD 400.8, BOD 178,PO4 7.69 and So4 139. The efficiency of total coliform and Ecoli removal efficiency was 33.3% and 37.3% in 2015 compared to 87 % and 55.3% in 2011. The efficiency of BOD was 70.8 in 2015 compared to 75.8 % in 2011. The decrease was 5%. The efficiency of EC was 9.8 % in 2015 compared to 27.3 % in 2011. The decrease in the efficiency with time was due to accumulation of solids in the constructed wetland. Soil pH and EC were 6.67 and 2.65. No heavy metal accumulation in soil was observed. Both grew water and soil analysis after five years of treatment remains within the accepted Palestinian reuse standards.

Insights of the Removal Mechanisms of Pharmaceutical and Personal Care Products in Constructed Wetlands

Pharmaceutical and personal care products (PPCPs) are chemicals employed in human healthcare, veterinary, medical diagnosis, and cosmetics, which have increasingly polluted water sources. Extensive research has demonstrated constructed wetlands (CWs) technology as a low-cost but efficient approach for PPCPs removal. There has been a growing interest to better understand the degradation mechanisms of PPCPs in wetland cells. Data corroborated in this review show that these degradation mechanisms include photolytic degradation, adsorption, phytodegradation, and microbial degradation. Each of these degradation mechanisms performs differently in wetland cells. This review also highlights the lack of research works to quantify the contribution of these degradation mechanisms to the overall efficiency of CWs to remove PPCPs as a major bottleneck for further application of this technology. The ultimate goal is to apply and prioritize a suitable degradation mechanism for successfully eliminating corresponding PPCPs. This review, therefore, provides further insights to (i) elucidate the importance of these removal mechanisms, and (ii) quantify their contribution in overall PPCPs removal processes. This review aims to understand the importance and contribution of degradation mechanisms of PPCPs removal in constructed wetlands. The degradation mechanisms of PPCPs in constructed wetlands depended on various conditions; yet, which factors are preferred? Furthermore, the number of research works, related to quantifying the contribution of degradation mechanisms, is limited. The hydrophobic/hydrophilic character, reflecting as log Kow (or log Dow), is the most commonly used. The photolytic degradation is appropriate with low and moderate hydrophobic values (log Dow from − 2.3 to 3). The role of adsorption is moderate, while it is more efficient with the higher hydrophobic compounds. The media is important for plant growth and micro-organism community development. The plant uptake is better for PPCPs with higher hydrophobicity (log Kow from 1 to 4). However, it is difficult to quantify their contribution and the number of related studies is limited.

New approaches to enhance pollutant removal in artificially aerated wastewater treatment systems

Freshwater ecosystems sustain human society through the provision of a range of services. However, the status of these ecosystems is threatened by a multitude of pressures, including point sources of wastewater. Future treatment of wastewater will increasingly require new forms of decentralised infrastructure. The research reported here sought to enhance pollutant removal within a novel wastewater treatment technology, based on un-planted, artificially aerated, horizontal subsurface flow constructed wetlands. The potential for these systems to treat de-icer contaminated runoff from airports, a source of wastewater that is likely to grow in importance alongside the expansion of air travel and under future climate scenarios, was evaluated. A new configuration for the delivery of air to aerated treatment systems was developed and tested, based on a phased-aeration approach. This new aeration approach significantly improved pollutant removal efficiency compared to alternative aeration configurations, achieving >90% removal of influent load for COD, BOD5 and TOC. Optimised operating conditions under phased aeration were also determined. Based on a hydraulic retention time of 1.5 d and a pollutant mass loading rate of 0.10 kg d−1 m−2 BOD5, >95% BOD5 removal, alongside final effluent BOD5 concentrations <21 mg L−1, could be achieved from an influent characterised by a BOD5 concentration > 800 mg L−1. Key controls on oxygen transfer efficiency within the aerated treatment system were also determined, revealing that standard oxygen transfer efficiency was inversely related to aeration rate between 1 L and 3 L min−1 and positively related to bed media depth between 1500 mm and 3000 mm. The research reported here highlights the potential for optimisation and subsequent widespread application of the aerated wetland technology, in order to protect and restore freshwater ecosystems and the services that they provide to human society.

Macrophytes Potentials of Indigenous Plant Species for Faecal Sludge Constructed Wetland Treatment System

Constructed Wetland technology has positive potentials for the management of faecal sludge in developing countries of Sub-Saharan Africa. However, identification of indigenous plant species that can survive the high levels of faecal sludge toxicity is a major challenge to its application. Preliminary study highlighted a high complexity of potential macrophytes species identification within the Sahelian context. This study is a preliminary stage of acclimatising four indigenous plant species Setaria verticillata (SV), Cymbopogon nardus (CN), Bambusa vulgaris (BV) and Typha latifolia L. (TL) to wastewater contamination in pot experiment. Macrophytes were subjected to wastewater irrigation from maturation basin of the 2iE Ouagadougou campus wastewater treatment plant. Macrophytes growth was monitored weekly by three growth parameters (No. of Plants per pot, Plant Height and No. of Leaves per pot). Initial plant height of 46.6, 75.7 and 61.7cm for SV, BV and TL, increased to 98, 103.1 and 93.5 cm after 13, 11 and 8 weeks of planting respectively. After 11 weeks of planting the average height of CN, reduced from 66.3 to 42 cm. Number of plants averagely increased from 25 to 130, 4 to15, 4 to 10 and 4 to 8 respectively for SV, CN, BV and TL. Average leaves per pot increased from 95 to 839, 19 to 67, 368 to 508 and 4 to 49 for SV, CN, BV and TL respectively. Variations of average growth rate among species were statistically insignificant. The results thus indicate satisfactory reed potentials with wastewater acclimatisation.

Constructed wetland modelling for watershed ecosystem protection under a certain economic load: A case study at the Chaohu Lake watershed, China

The two major aims of watershed management are regional economic development and watershed ecosystem protection. In this paper, constructed wetland (CW) technology is employed to examine watershed ecosystem protection under a certain regional economic load. The Chaohu Lake watershed in China was chosen as the target study area and fuzzy random variables used to describe the uncertainties. Then, a bi-level optimization model for watershed-scale CW planning was developed and applied to the Chaohu Lake watershed with the aim of protecting ecosystem health. To solve the model, a fuzzy random simulation-based nested simulated annealing algorithm was designed. The results showed that there was a “finite sum game” relationship between economic development and ecosystem health within the Chaohu Lake watershed. Under a probability and possibility of 0.9, to achieve the ecological goal F1=70, it was estimated that a 348.19 (ha) CW needed to be constructed. The impacts of environmental policies and economic development on the watershed ecosystem were found to be significant. One of the key practical results indicated that: in the Chaohu Lake watershed, the water environmental treatment of rivers should take precedence over that of lakes; a result which could be of assistance to local government policy making.

Peat as Substrate for Small-Scale Constructed Wetlands Polishing Secondary Effluents from Municipal Wastewater Treatment Plant

With the recent development of constructed wetland technology, it has become a mainstream treatment technology for the mitigation of a variety of wastewaters. This study reports on the treatment performance and pH attenuation capacity of three different configurations of small-scale on-site surface flow constructed wetlands (SFCW): T1 (Peat + Typha latifolia), T2 (T. latifolia alone), and T3 (Peat alone) treating secondary effluent from the Amherstview Water Pollution Control Plant (WPCP) for two treatment periods (start-up period and operational period). The aim of this study was to compare the nutrients removal efficiencies between the different treatments, as well as to evaluate the effects of substrate and vegetation on the wetland system. For a hydraulic retention time of 2.5 days, the results showed that all treatment systems could attenuate the pH level during both the start-up and operational periods, while significant nutrient removal performance could only be observed during the operational period. Peat was noted to be a better SFCW substrate in promoting the removal of nitrate (NO3-N), total nitrogen (TN), and phosphorus. The addition of T. latifolia further enhanced NO3-N and TN removal efficiencies, but employing T. latifolia alone did not yield effluents that could meet the regulatory discharge limit (1.0 mg/L) for phosphorus.

Resilience of carbon and nitrogen removal due to aeration interruption in aerated treatment wetlands

Treatment wetlands have long been used for domestic and industrial wastewater treatment. In recent decades, treatment wetland technology has evolved and now includes intensified designs such as aerated treatment wetlands. Aerated treatment wetlands are particularly dependent on aeration, which requires reliable air pumps and, in most cases, electricity. Whether aerated treatment wetlands are resilient to disturbances such as an aeration interruption is currently not well known.In order to investigate this knowledge gap, we carried out a pilot-scale experiment on one aerated horizontal flow wetland and one aerated vertical flow wetland under warm (Twater>17°C) and cold (Twater<10°C) weather conditions. Both wetlands were monitored before, during and after an aeration interruption of 6d by taking grab samples of the influent and effluent, as well as pore water. The resilience of organic carbon and nitrogen removal processes in the aerated treatment wetlands depended on system design (horizontal or vertical flow) and water temperature. Organic carbon and nitrogen removal for both systems severely deteriorated after 4–5d of aeration interruption, resulting in effluent water quality similar to that expected from a conventional horizontal sub-surface flow treatment wetland. Both experimental aerated treatment wetlands recovered their initial treatment performance within 3–4d at Twater>17°C (warm weather) and within 6–8d (horizontal flow system) and 4–5d (vertical flow system) at Twater<10°C (cold weather). In the vertical flow system, DOC, DN and NH4-N removal were less affected by low water temperatures, however, the decrease of DN removal in the vertical flow aerated wetland at Twater>17°C was twice as high as in the horizontal flow aerated wetland. The quick recovery of treatment performance highlights the benefits of aerated treatment wetlands as resilient wastewater treatment technologies.

Effect of design and operational conditions on the performance of subsurface flow treatment wetlands: Emerging organic contaminants as indicators

Six pilot-scale subsurface flow treatment wetlands loaded with primary treated municipal wastewater were monitored over one year for classical wastewater parameters and a set of emerging organic compounds (EOCs) serving as process indicators for biodegradation: caffeine, ibuprofen, naproxen, benzotriazole, diclofenac, acesulfame, and carbamazepine. The wetland technologies investigated included conventional horizontal flow, unsaturated vertical flow (single and two-stage), horizontal flow with aeration, vertical flow with aeration, and reciprocating. Treatment efficiency for classical wastewater parameters and EOCs generally increased with increasing design complexity and dissolved oxygen concentrations. The two aerated wetlands and the two-stage vertical flow system showed the highest EOC removal, and the best performance in warm season and most robust performance in the cold season. These three systems performed better than the adjacent conventional WWTP with respect to EOC removal. Acesulfame was observed to be removed (>90%) by intensified wetland systems and with use of a tertiary treatment sand filter during the warm season. Elevated temperature and high oxygen content (aerobic conditions) proved beneficial for EOC removal. For EOCs of moderate to low biodegradability, the co-occurrence of aerobic conditions and low content of readily available carbon appears essential for efficient removal. Such conditions occurred in the aerated systems and with use of a tertiary treatment sand filter.

Application of constructed wetlands for treating agricultural runoff and agro-industrial wastewater: a review

With the unique advantages of cost-effectiveness and low energy consumption, constructed wetlands (CWs) are commonly used for treatment of secondary municipal wastewaters. Over the last decades, CWs have gained increased popularity for treating agricultural runoff and agro-industrial wastewater. This review highlights the practice, application, and research on wetland technology, placing them in the overall context of the need for reliable and sustainable solutions to managing agricultural runoff and agro-industrial wastewater. A critical assessment of the performance and effectiveness of wetland systems for removing various contaminants of importance to agriculture is presented. The design parameters and operational conditions affecting the efficiency of contaminant removal in CWs receiving agricultural runoff and agro-industrial wastewater are also discussed. The role of proper pretreatment, artificial aeration, effluent recirculation, in-series design, and microbial dynamics on the enhancement of treatment is provided. Challenges and perspectives for future research on agricultural treatment wetlands are also addressed.

Ecologically Designed Sanitary Sewer Based on Constructed Wetlands Technology � Case Study in Managua (Nicaragua)

Ecologically Designed Sanitary Sewer Based on Constructed Wetlands Technology � Case Study in Managua (Nicaragua)

Comparative study of domestic wastewater treatment by mature vertical-flow constructed wetlands and artificial ponds

This study compares the performance, design and operation variables of two wetland technologies treating domestic wastewater: an experimental artificial pond system and a mature experimental vertical-flow constructed wetland system. The wetland system planted with Phragmites australis (Cav.) Trin. ex Steud. (common reeds) was operated between June 2011 and October 2015, while the pond system was only operated between July 2015 and October 2015. Three different types of ponds were compared: ponds with wastewater; ponds with wastewater and reeds; and ponds with wastewater, reeds and aeration. Findings regarding the performances of mature wetlands showed that the wetland systems improved the water quality except for ortho-phosphate-phosphorus (PO4−P), where the treatment performance reduced slightly over time. In general, the aerated pond systems showed better treatment performances in terms of ammonia-nitrogen (NH4−N) and PO4−P‎. Both systems were linked with medium to high levels of five-day biochemical oxygen demand (BOD) removal. The highest COD and SS removals were observed for wetlands in comparison to ponds. Moreover, mature wetlands were better in removing NH4−N and PO4−P than ponds unless the ponds were aerated. The nitrate-nitrogen (NO3−N) concentration increased in the aerated ponds reflecting the high oxygen availability.

Grass filtration in parallel with VFCW technology for community wastewater treatment through the king's initiative nature-by-nature process

The 15-year research is aimed to apply the Vertical Flow Constructed Wetland (VFCW) technology along with growing Star, Kallar, Coast couch grasses for community wastewater treatment as obtained from Phetchaburi municipal after anaerobic digesting inside the 18.5 km High-density Polyethylene (HDPE) pipe. The results found that pH value did not evidently show any change of influent to effluent among grass species but drastic change due to treatment efficiency in Biological Oxygen Demand (BOD), Total Kjeldahl Nitrogen (TKD), Total Phosphorus (TP), and Total Potassium (TK) due to supporting rapidly growing of Star, Kallar, and Coast couch grasses, and also some parts of organic forms to escape from the VFCW technical units as volatile gaseous chemicals; and precipitating down to the VFCW technical unit beds as sludge. The Star and Coast couch grasses showed higher potential in community wastewater treatment efficiency than Kallar grass but treating power were not different in wide ranges. Besides, the heavy metals (Pb, Cd, Hg as example) were contaminated in both treated wastewater and sludge (sediment). However, the influent and effluent as inflow and outflow of VFCW technical units found very low contamination but three grasses (Star, Kallar, and Coast couch) showed their eligibility in treating heavy metals, especially when their age at 45-day growth as the same findings of treating BOD, TKN, TP, and TK according to meet highest treatment efficiency at age of 45 days. In other words, the harvesting age at 45 days was not only reached the maximum treatment efficiency as well as maximum grass biomass but also kept away from heavy contamination.

Comparative study of cold-climate constructed wetland technology in Canada and northern China for water resource protection

This paper aims to be a cursory relative comparison between applications of custom-designed constructed wetland systems for specific water resources protection in Canada and northern China. Comparing constructed wetlands can be difficult and at times misleading; they are custom built to deal with specific target wastewater at specific locations and differ not only in physical shape and dimension, but in vegetation cover, hydraulic retention time, and pollutant loading rates. Treatment efficiencies defined by the Canadian and northern Chinese experience vary considerably. Experience in both countries shows that the majority of effluent values are generally better than those required by discharge standards in Canada and China. Examples provided from both countries demonstrated that plants can play a role in constructed wetland systems and make a difference in treatment efficiency. A review of the available case studies on cold weather treatment in both countries indicates that this technology is feasible in Canada and northern China, although further monitoring data are needed to optimize wetland design and ensure that the effluent quality standards are consistently met. Constructed wetland systems in both countries have an apparent advantage in construction costs, and the costs for treatment and operation and maintenance of these systems are much lower than those of conventional wastewater treatment plants. Land requirements for constructed wetlands present one of the factors most limiting their broader use, especially in China, where land resources are scarce and population density is high.

Design and performance evaluation of a highly loaded aerated treatment wetland managing effluents from a food processing industry in Denmark

Treating highly loaded industrial effluents are challenging when treatment wetlands (TWs) are the choice selected for treatment. If TWs are selected as the solution, passive systems demand relatively large areas and may generate operational limitations and are not flexible in case of new treatment demands since no process adjustments can be made once the system is built. New types of intensified TW, such as aerated systems, have opened new possibilities in the field of the Wetland Technology and have shown capacity to treat several types of wastewater (WW). Aerated wetlands have been built across the USA and several European countries, but not a single system has been built in Denmark as to date. Thanks to an EU funded project and the cooperation of several partners under a consortium with the acronym HIGHWET, a new system is being built at the premises of a food processing factory in the vicinity of Faarup Denmark. The system will treat the WW generated at the plant and consists of a pretreatment system in the form of an anaerobic reactor, followed by two 1 m deep vertical flow beds, one of them aerated while the other bed is not aerated. Following these beds, the plant has two horizontal sub-surface flow beds fitted with aeration. For improving the P removal, media with high P binding capacity is are being used as filling material. In additiuon and for research purposes, the influent pump well plant is fitted with a dosing system in order to obtain pollutant loads at will so performance limits and kinetic constants can be established from the performance of the plant.

Constructed wetlands as sustainable ecotechnologies in decentralization practices: a review.

Recently, a range of novel and cost-effective engineered wetland technologies for decentralization practices of domestic wastewater treatment have been developed with ecological process modification, the use of functionalized plants, and advanced biofilm formation. However, selecting the one that can be more appreciated for on-site sanitation is still uncertain. This paper reviews the role of plants, media materials, microorganisms, and oxygen transfer in domestic wastewater purification through constructed wetlands (CWs). The effectiveness of traditional and recently developed CWs and the necessity of an induced biofilm attachment surface (BAS) in these systems for the treatment of domestic sewage are presented. This review also elucidates the idea of CWs for domestic wastewater characteristics highly stressed by total dissolved solids and the adaptive strategies in mitigating the cold climate impacts on their efficiencies. Further research needed to enhance the stability and sustainability of CWs is highlighted. By a more advanced investigation, BAS CWs can be specified as an ideal treatment process in decentralization.

The Concept of Construction of Hybrid Constructed Wetland for Wastewater Treatment in Roztocze National Park

Roztocze National Park (RNP) is one of 23 national parks in Poland. It was created in 1974 both to protect the natural and cultural heritage as well as to share the park area for science, education and tourism. In caring for the environment, the park removed asbestos coverage, performs thermo-modernization using renewable energy sources by the installation of solar panels and photovoltaic cells on the roofs of buildings, and pellet stoves are installed in boiler rooms. Part of these actions includes the application of innovative technologies for water and wastewater, related to e.g. recovery of rainwater for washing cars and the construction of wastewater treatment wetlands. RNP has been spreading for many years the knowledge about the methods used to most effectively care for the natural environment. Constructed wetland (CW) technology could be one of such methods. The current research shows that facilities working in CW technology provide high pollutant removal and full guarantee of high ecological impact with low operating cost, so they can be used to protect the aquatic environment in protected areas and valuable landscapes. The paper presents a concept of solving the problems of wastewater treatment by means of using hybrid constructed wetland in three villages in the forest of Roztocze National Park. The advantages of the proposed technology are easy and simple operation, high resistance to irregular supply of water treatment and very low operating costs compared to conventional solutions. The natural look of CWs allows easy incorporation into the existing landscape.

Potential for use of industrial waste materials as filter media for removal of Al, Mo, As, V and Ga from alkaline drainage in constructed wetlands – Adsorption studies

The potential to remove Al, Mo, V, As and Ga from alkaline (pH 8.0–8.6) drainage originating from seawater neutralized bauxite processing residue storage areas using constructed wetland technology was studied in a laboratory study. Bauxite processing residue sand, bauxite, alum water treatment sludge and blast furnace slag were investigated as potential active filter materials. Al was shown to precipitate as Al(OH)3 in the pH range 7.0–8.0 in aqueous solution and 6.0–8.5 in the presence of silica sand particles that provided a surface for nucleation. For V As Mo and Ga, adsorption to the surfaces of the adsorbents decreased greatly at elevated pH values (>pH 6–9). Water treatment sludge and bauxite had a greater ability to adsorb V, As and Mo at high pH (As and V at pH 7–9 and Mo at pH 5–7) than processing sand and slag. Adsorption isotherm data for As and V onto all four adsorbent than processing sand and slag. Adsorption isotherm data for As and V onto all four adsorbent materials fitted equally well to the Langmuir and Freundlich equations but for Ga, and to a lesser extent Mo, the Freundlich equation gave higher R2 values. For all four ions, the maximum adsorption capacity (Langmuir value qmax) was greatest for water treatment sludge. Bauxite adsorbed more Mo, Ga and V than residue sand or slag. The pseudo-second order equation gave a better fit to the experimental kinetic data than the pseudo-first order model suggesting that chemisorption rather than diffusion/exchange was the rate limiting step to adsorption. It was concluded that water treatment sludge and bauxite were the most effective adsorbents and that for effective removal of the target ions the pH of the drainage water needs to be decreased to 6.0–7.0.

Evaluation of commercial floating treatment wetland technologies for nutrient remediation of stormwater

Floating treatment wetlands (FTWs) are a relatively new water treatment practice that consists of emergent wetland plants planted on floating mats constructed of buoyant material. This study utilized batch-fed mesocosms, with a seven-day retention time, to investigate the total nitrogen (TN) and phosphorus (TP) remediation capability of two commercially available FTW technologies using runoff from a combined irrigation holding and stormwater retention pond. Nutrients in the pond water are attributed to runoff from nearby fertilized research plots upgradient. The FTW technologies included Beemats (Beemats LLC, New Smyrna Beach, FL, USA) and BioHaven® floating islands (Floating Island International, Inc. Shepard, MT, USA) planted with Juncus effusus (soft rush). Due to an increase in TN and TP in the initial phase of the experiment during the plant establishment phase (weeks 1–8), BioHaven®nutrient removal was lower over the entire experimental period than the Beemat treatment. Differences between the two treatments, such as mat material or substrate materials and/or additives may account for this difference. The BioHaven® FTW removed 25% and 4%, while the Beemat removed 40% and 48% of the TN and TP, respectively expressed in terms of net removal over the entire study. During the plant growth season (weeks 9–18 of the study), the two technologies showed similar nutrient removal rates: for TN:0.026±0.0032 and 0.025±0.0018, and for TP:0.0074±0.00049 and 0.0076±0.00065g/m2/day for Beemat and Biohaven®, respectively. A control treatment, meant to reflect nutrient removal within the pond without the presence of plants, yielded 28% and 31% removal of TN and TP, respectively. Thus, the Beemat mat yielded a significant positive net removal of TN and TP. The BioHaven® biomass was significantly greater than the Beemat treatment. Both treatments showed greater biomass accumulation in shoots rather than in roots. Plant nutrient content was similar between the two treatments.

Assessing the sustainability of small wastewater treatment systems: A composite indicator approach

The assessment of the sustainability of wastewater treatment (WWT) systems has gained interest in recent years. However, most previous studies have focused on environmental and/or economic dimensions ignoring social aspects. Moreover, they tend to be based on sets of indicators rather than providing a holistic assessment. To overcome this limitation, this paper proposes an innovative methodology to assess the sustainability of WWT systems based on the development of a composite indicator embracing economic, environmental and social issues. Subsequently, the global sustainability of seven WWT technologies for secondary treatment in small communities is compared. The joint application of the analytical hierarchical process (AHP) to assign weights to each indicator allows the incorporation of the preferences of experts. Initially, the global sustainability of the WWT technologies evaluated is quite similar. However, a scenario analysis illustrates that constructed wetlands technology is the most sustainable in five out of the seven scenarios evaluated. Moreover, extended aeration and rotating biological contactors are identified as the technologies with the lowest variability in their sustainability. Hence, in an uncertain context, they might be considered the preferred options. The proposed approach contributes to ease of interpretation of a complex problem such as the selection of the most sustainable WWT alternative.

Application of Artificial Wetland Technology in Rural Water Pollution Control

In recent years, with the quickening pace of urbanization in our country, rural economic development and living standards have greatly improved, however, at the same time, economic development also makes the rural water environment increasingly serious. This paper briefly introduce the sources and characteristics of rural water pollution source, collection and treatment style, and according to the existing rural conditions, combined with environmental protection, mainly studied the application of ecological wetland in the rural water pollution control, and briefly describes the mechanism of artificial wetland water purification, common water purification technology and some Suggestions for rural water pollution control, hoping that it can offer some help to improve rural water environment in the future.