Introduction to Rural Water Treatment Technology

At present, there are three main types of technologies and processes used domestically and internationally for decentralized treatment of rural sewage (with a daily discharge of 10m3-2000m3).

The first type is to draw on the successful experience of secondary biochemical treatment in urban sewage treatment plants, miniaturize some traditional secondary biochemical treatment processes in urban sewage treatment plants, and apply them to decentralized sewage treatment in villages and towns. Such as SBR, oxidation ditch A/O， Even A2/O, MBR, and so on. From a technical perspective, these technologies and processes are relatively mature and can meet the requirements of wastewater treatment. However, these technologies and processes are usually quite complex and require a lot of equipment. Therefore, the investment is relatively large, the system maintenance and management are complex, the energy consumption and operation management costs are high, and there may also be some secondary pollution problems.

The second type is to adopt relatively simple ecological sewage treatment technologies, including artificial wetlands, oxidation ponds, land treatment systems, etc. The advantages of this type of technology are simple process, low investment, low energy consumption, easy maintenance, and environmental friendliness. The disadvantage is that the treatment efficiency is relatively low, and stable treatment effects and long-term normal operation of the system usually need to be achieved under certain conditions, such as lower hydraulic and organic loads and longer HRT, which requires a large available site and immature technology.

The third type is anaerobic treatment technology. Compared with traditional aerobic biotechnology, anaerobic biological treatment technology has the advantages of simple process, low energy consumption, small sludge production, low nutritional requirements, and wide adaptability to water sources. Therefore, anaerobic technology has received widespread attention. For the sewage treatment of villages and towns in our country, in some villages and towns with conditions, especially those with both domestic sewage pollution and industrial or aquaculture wastewater pollution, using anaerobic biological treatment as a pre-treatment technology is a good choice.

The development of integrated small and medium-sized sewage treatment devices that integrate pre-treatment, secondary treatment, and deep treatment is a trend in the development of decentralized sewage treatment both domestically and internationally, and has broad application prospects in rural domestic sewage treatment.

2 Purification tank process

2.1 Process Introduction

Purification tank technology originated in Japan, with a penetration rate of up to 84% and a user population of about 15 million. As early as 1983, Japan passed laws related to purification tanks to ensure and promote their popularity. The excellent rural sewage treatment in Japan is largely due to the use of purification tanks.

existIn 2005, our company began to independently develop purification tank technology that is in line with national conditions. This technology is in line with Japan's purification tank technology, with better effluent quality, lower operating costs, and stable operation30This year is more suitable for treating domestic sewage in rural China. And in2008In collaboration with the Tianjin Municipal Agricultural Commission, many demonstration projects were established and awarded multiple times. Currently, the longest running purification tank isFor 8 years, there have been no accidents during the process, and the effluent quality continues to meet the standard, with a positive response from the public.

picture2-1Purification tank process flow

CurrentlyA2OTechnological development has becomeA/O/A/OThe technology has been applied in advanced countries and some regions of China. according toA/O/A/OThe advantages of phosphorus removal, nitrogen removal, energy saving, and emission reduction in the process are combined with our independent intellectual property rightsA/O/A/OOn the basis of the process, biofilm technology is added to reduce the occurrence of sludge in the treatment process. A series parallel treatment process with purification tanks as the unit has been developed. The single purification tank is an efficient bioreactor, and the internal shell adopts flat push flow and full mixed flow modes, greatly suppressing short circuits or unnecessary backmixing in the process. Due to the use of biofilm, it not only plays a role in filtration, but also in adsorption and biodegradation, effectively reducing the occurrence of sludge and improving the efficiency of biological treatment.

The purification tank can be relatively renovated according to needs, which can fully aerate the body or partially aerate according to demand, achievingA/O/A/OThe process can adopt multiple units in series or multiple units in series and parallel according to the processing capacity. Especially suitable for domestic sewage treatment in rural areas and rural tourism.

2.2processing mode

The purification tank system can be used for both single household and multi household types. One multi household combined purification tank can be used for the treatment of up to five households' domestic sewage. More importantly, multiple purification tanks can be used in series and parallel for centralized treatment systems. These systems have been applied:

tenfivehouseholdagritainmentDomestic sewage treatment,Fourteen hydrolysis tanks are connected in parallel, and two purification tanks are connected in series

New rural building domestic sewage treatment process

Domestic sewage treatment for ten buildings, with two hydrolysis tanks connected in parallel and two purification tanks connected in series

3Technical advantages

（1）The four different processing modes, namely decentralized processing (single household, multi household, and building) and centralized processing (centralized village style), can perfectly address the basic situation of various rural areas in China today.

（2）The decentralized processing mode effectively solves the problems of difficulty and high investment in laying rural pipeline networks, greatly reducing investment costs.

（3）Mature technology, stable treatment process, suitable for the characteristics of large fluctuations in water quality and quantity of rural sewage.

（4）Installation is not affected by terrain, with short time and quick results.

（5）The effluent quality meets the standard, and the treated clean water is not discharged, which can effectively maintain the water volume around the residential area and can be directly used for irrigation.

（6）Built up: The equipment has simple structure, small footprint, and low price.

（7）Affordable: Strong process load resistance, good effluent quality, foolproof operation, unmanned operation, convenient management.

（8）Affordable: low power consumption and low operating costs; Low maintenance costs and long equipment lifespan30