Rural Domestic Wastewater Treatment Research Articles

Integrated Processes of Anoxic/Oxic Bioreactor and Artificial Wetland for Rural Domestic Wastewater Treatment

This paper examined the treatment of rural domestic wastewater. Influent and effluent samples were experimented for Chemical oxygen demand (COD), NH4+-N, NO3--N and TP in the Taihu Lake Environmental laboratory of Southeast University in Wuxi. Different hydraulic retention time (HRT) and recycle ratios were applied to appraise their influence on removal efficiency. The wastewater temperature was controlled between 20 to 24°C and pH ranges 7.6 – 8.1. The result revealed average COD, NH4+-N, NO3- -N and TP removal efficiencies of 77.2, 74.1, 94 and 83% with optimum HRT of 3hrs and recycle ratio of 2 respectively. The obtained results confirmed that, the integrated processes of anoxic/oxic bioreactor and artificial wetland was viable and proficient in domestic wastewater treatment.

Experimental Study on Anoxic/Oxic Bioreactor and Constructed Wetland for Rural Domestic Wastewater Treatment

This study examined the removal of nutrients from the domestic wastewater through the application of integrated anoxic/oxic (A/O) bio-reactor and constructed wetland system. Influent and effluent samples were collected from the system and experimented for Chemical Oxygen Demand (COD), NH₄+-N, NO₃--N and TP in the laboratory. Different Hydraulic Retention Time (HRT) and recycle ratios were applied in the reactor to evaluate their influence on removal efficiency of nutrients. The temperature was controlled between 20 to 24°C and pH ranges was 7.6-8.1. The result revealed average COD removal efficiencies of 47, 68, 74, 83 and 85% at HRT of 1.5, 4, 2, 3 and 5 h. The average removal of NH4+-N was 60.3, 63.0, 64.4, 71 and 91.8 % operated with HRT of 2, 3, 5, 1.5 and 4 h, respectively. The average removal of NO3- -N was 92, 94, 95 and 97% run with HRT of 2, 1.5, 3, 5 and 4 h, respectively. The average removal of TP was 78, 85, 88 and 89% operated with HRT of 5, 3, 2 and 1 h. This system removed up to 74.1, 94.4 and 85% of NH4+-N, NO3- -N and TP with proper pH control using external source of alkalinity. The result showed the optimum recycle ratio of 3. The results obtained attest that, the integrated anoxic/oxic bioreactor and constructed wetland is feasible and efficient for wastewater treatment.

Rural Water Environment and Domestic Wastewater Treatment Control Technique Analysis of Dianchi Lake Basin

The eutrophication problem of Dianchi Lake has been more and more serious. Based on the current situation of rural water environment,this paper carried out a survey of Dianchi Lake Basin rural water environment, in order to explore the proper technique for the local sewage pollution control. According to the water environment management requirements, this paper suggested the rural sewage treatment techniques and the treatment degree should be divided into four levels, provided a basis for Dianchi Lake Basin rural water environment control.

Constructed Wetland in a Compact Rural Domestic Wastewater Treatment System for Nutrient Removal

Abstract Direct discharge of scattered rural sewage into surface water bodies with no efficient and economic treatment processes is one of the main reasons for the deteriorative aquatic environment in China. In this study, a simplified pilot-scale rural wastewater treatment system has been proposed. The system consisted of an anaerobic digestion tank (for organic substances pretreatment), an aerobic five-cell submerged biofilm reactor (for organic substances degradation), and a constructed wetland (CW; for nutrients removal and effluent quality control) in sequence. A five-step water-dropping aeration technique was incorporated in the biofilm reactor for oxygen replenishment with one pump, the only equipment applied in the system that involved in water elevation and effectively alleviated the oxygen stress in the CW for nutrient removal improvement. Effects of economic vegetation species (water spinach vs. water bamboo), packing media (coal cinder vs. gravel), and flow patterns (submerged horizontal flow ...

Enhancement of rural domestic sewage treatment performance, and assessment of microbial community diversity and structure using tower vermifiltration

The performance of a novel three-stage vermifiltration (VF) system using the earthworm, Eisenia fetida, for rural domestic wastewater treatment was studied during a 131-day period. The average removal efficiencies of the tower VF planted with Penstemon campanulatus were as follows: chemical oxygen demand, 81.3%; ammonium, 98%; total nitrogen, 60.2%; total phosphorus, 98.4%; total nitrogen, mainly in the form of nitrate. Soils played an important role in removing the organic matter. The three-sectional design with increasing oxygen demand concentration in the effluents, and the distribution of certain oxides in the padding were likely beneficial for ammonium and phosphorus removal, respectively. The microbial community profiles revealed that band patterns varied more or less in various matrices of each stage at different sampling times, while the presence of earthworms intensified the bacterial diversity in soils. Retrieved sequences recovered from the media in VF primarily belonged to unknown bacterium and Bacilli of Firmicutes.

Rural domestic wastewater treatment in Norway and Poland: experiences, cooperation and concepts on the improvement of constructed wetland technology

This article describes Norwegian and Polish experiences concerning domestic wastewater treatment obtained during nearly 20 years of operation for constructed wetland (CW) systems in rural areas and scattered settlements. The Norwegian CW systems revealed a high performance with respect to the removal of organic matter, biogenic elements and faecal indicator bacteria. The performance of the Polish CW systems was unstable, and varied between unsatisfied and satisfied treatment efficiency provided by horizontal and vertical flow CWs, respectively. Therefore, three different concepts related to the improvement of CW technology have been developed and implemented in Poland. These concepts combined some innovative solutions originally designed in Norway (e.g. an additional treatment step in biofilters) with Polish inspiration for new CWs treating rural domestic wastewater. The implementation of full-scale systems will be evaluated with regard to treatment efficiency and innovative technology; based on this, a further selection of the most favourable CW for rural areas and scattered settlements will be performed.

Sustainable Sanitation as a Part of an IWRM in the Karst Area of Gunung Kidul: Community Acceptance and Opinion

To overcome the problem of water scarcity in a rural karst area located in Gunung Sewu, Yogyakarta, Indonesia, water from an underground cave (Bribin Cave) is pumped and distributed to the people. Since karst aquifers are often considered as highly vulnerable to contamination from human activities, potential problems caused by current sanitation and hygiene practices in the recharge region must be anticipated. About 90% of the people in the recharge area use pour flush syphon toilets with poorly designed septic tanks and the rest have simple pit latrines. However, the existing septic tanks are very poorly designed and are actually only improved infiltration pits. One possible option to reduce the risk of aquifer contamination is to promote sustainable sanitation, which combines hygienic aspects with recycling of nutrients from human feces and urine. Sustainable sanitation comprises different technologies including low cost technology, which can be afforded by the community and provide economic benefit to the low income inhabitants in Gunung Sewu. The technology proposed is urine diverting and composting toilets. This paper presents the existing condition of rural domestic wastewater treatment and the opinion/ acceptance of the community in karst area of Gunung Sewu towards urine diverting and composting toilets. The results of the survey shows that although the acceptance of using the composting toilet is not high (25% to 43%), the interest of the community in using the end product is relatively high. While the acceptance of composting fertilizer from feces (humanure) ranges from 37% to 57%, urine fertilizer attracts 42%-71% respondents' interest.

Wastewater treatment performance of a vermifilter enhancement by a converter slag–coal cinder filter

The study aimed at investigating rural domestic wastewater treatment performance through vermifilter enhancement by a converter slag–coal cinder filter. The research was carried out by column experiments in a lab scale. Results showed the average removal rate of TCOD, BOD, ammonia nitrogen (NH 4 +-N) and phosphorus removal by the system were 78.0%, 98.4%, 90.3%, 62.4%, respectively at a hydraulic loading rate of 4 m 3 m −2 day −1. Vermifiltration was effective for insoluble organic matter and suspended solid removal, and the converter slag–coal cinder filter played an important role in phosphorus removal. The molecular weight of particles in the influent and effluents from every unit of the system were distributed in a wide range between 0.1 kDa and 10,000 kDa with predominance of values between 10 kDa and 300 kDa; the major portion of soluble material are high MW compounds. In addition, the optimal design parameters for vermifiltration and converter slag and coal cinder filters, respectively, were studied in the experiments.

A Novel Bio-Eco Technology Combined System for Rural Domestic Wastewater Treatment in a Tourism Area: A Full-Scale Study

Characteristics of rural water consumption and sewage discharge in a tourism area were determined through an investigation of local villages in Lugu Lake (Yunnan Province). Based on the results of this evaluation, a novel bio-eco technology combined system was developed for high-quality wastewater treatment and recycling at low cost in the rural area. In this combined system, the bio-technique unit is an integrated oxidation ditch with vertical circle (IODVC), and the eco-technique unit consists of a wetland eco-filter, a subsurface infiltration and an eco-ditch. A full-scale wastewater treatment plant of this combined system was built in Lige Village, which is located at the Lugu Lake Tourism Area. The performance of the bio-eco combined system showed that its effluent quality reached up to grade III of the surface water standards (GB3838-2002), that is, the concentration of chemical oxygen demand (COD), ammonia nitrogen (NH4+-N), and total phosphorus (TP) in final effluent was less than 10, 1, and 0.1 mg/L, respectively, whereas the COD of 140–300 mg/L, NH4+-N of 40–70 mg/L, and TP of 3–5 mg/L in the influent, respectively. Furthermore, evaluation of the P adsorption of the local soil revealed that the P was removed by the ecological treatment unit of the bio-eco combined system via the fixation and sorption of iron and aluminium in the soil. The effluent of the full-scale wastewater treatment plant was used as the source water of a local landscape ecological wetland. Results demonstrated that this bio-eco combined system could be a feasible technology for wastewater treatment in this kind of rural areas.

A Novel Combined System for Onsite Domestic Wastewater Treatment in Rural Areas

A combined system, which consisted of an innovative septic tank (IST) and compound media filter bed (CMFB), was used for onsite domestic wastewater treatment in a rural area. Performance of this system was evaluated by both bench-scale and pilot-scale experiments. The system showed relatively good removal efficiency of chemical oxygen demand (COD) and suspended solids, but removal efficiencies of total phosphorus (TP) and total nitrogen (TN) were not so impressive. Correlated regression models provided good estimates of the nutrient removal performance in this system. Hydraulic retention time (HRT) had a positive effect on nutrient removal. Ambient temperature had no obvious relationship with the suspended solids (SS) and TP removal in the system. By contrast, ambient temperature had a significant effect on COD removal (p < 0.05). Furthermore, the nutrients were hard to remove in cold seasons. During the operation period, this system showed high treatment capacity for rural domestic wastewater treatment with good landscape integration. Results demonstrated that this IST + CMFB system could be a practical technology for onsite domestic wastewater treatment in rural areas.