Advantages of psychrophiles in improving bio‐treatment efficiency of small size constructed wetlands during cold weather

Abstract

Constructed wetland technique for waste water treatment has many advantages, including high treatment efficiency, low investment and energy cost, and easy operation and maintenance. However, the inhibitive effect of low temperature on treatment efficiency remains a serious problem in cold weather for many small size wetlands. In this study, the application of cold-tolerating bacteria in maintaining the nitrogen waste treatment efficiency of small size constructed wetland during cold weather was investigated in Hebei province, northern China. Three strains of cold-resistant bacteria were purified, and their physiological characteristics in terms of growth rate and generation time under different growth conditions were tested. The effects of various environmental factors on the growth of these strains were also investigated, including ambient temperature, dissolved oxygen, carbon concentration, bio-retention time and pH. These strains of purified bacteria were then applied to constructed wetland systems, and their effects on nitrogen removal in cold temperatures were measured. It was found that these bacteria strains significantly improved the nitrogen removal efficiency of the constructed wetlands, suggesting a promising role that these microorganisms play in improving the efficiency of small size constructed wetlands in waste water treatment in cold weather.

Recent advances in biochar application for water and wastewater treatment: a review

“…In recent years, CWs have been widely used in wastewater treatment, including removal of N, P (Li et al, 2019), and some organic contaminants. Nevertheless, due to restricted oxygen supply and transport capacity, limited sorption capacity of the substrate, and inhibition of microbes and plants metabolism at low temperatures, the removal efficiency for N and P is severely hindered (Ying et al, 2010). Researchers have attempted to explore particular substrates to intensify the functions of CWs with high contaminants concentration, among which biochar has been favorably considered (Gupta, Prakash & Srivastava, 2015).…”

Peer Review #1 of "Recent advances in biochar application for water and wastewater treatment: a review (v0.2)"

“…In recent years, CWs have been widely used in wastewater treatment, including removal of N, P (Li et al, 2019), and some organic contaminants. Nevertheless, due to restricted oxygen supply and transport capacity, limited sorption capacity of the substrate, and inhibition of microbes and plants metabolism at low temperatures, the removal efficiency for N and P is severely hindered (Ying et al, 2010). Researchers have attempted to explore particular substrates to intensify the functions of CWs with high contaminants concentration, among which biochar has been favorably considered (Gupta et al, 2015).…”

Bacterial community shift and effects of the inclusion of a mixed psychrotrophic bacteria strain for sewage treatment in constructed wetland in winter seasons

“…A large number of microorganisms will be lost, making it di cult to control its long-term treatment effect. As a result, it is found that the function of two or more microbial strains to combine the dominant strains has a better synergistic effect than a single strain (Tang et al 2018;Ying et al 2010). In previous research, Ying et al (Ying et al 2010)explored the ammonia nitrogen removal rates of the three cold-resistant strains into the constructed wetland system in cold areas to remove the winter wastewater.…”

“…The majority of the isolated strains were Psychrotrophic bacteria (Westlake et al 1974;Atlas 1981;Järvinen, Melin, and Puhakka 1994;Yao et al 2013;Vacková, Srb, and Stloukal 2011), the molecular mechanism and related theory of its low temperature adaptability has also been studied. (Järvinen, Melin, and Puhakka 1994;Guo et al 2010;Ma et al 2009;Ying et al 2010). Pei et al (Pei, Yang, and Tian 2010) studied the effect of Bacillus.Subtilis FY99-01 on denitri cation e ciency in wetlands and showed that the addition of microbial strain could effectively increase the nitrate removal e ciency in wetlands.…”

“…As a result, it is found that the function of two or more microbial strains to combine the dominant strains has a better synergistic effect than a single strain (Tang et al 2018;Ying et al 2010). In previous research, Ying et al (Ying et al 2010)explored the ammonia nitrogen removal rates of the three cold-resistant strains into the constructed wetland system in cold areas to remove the winter wastewater. When the ambient temperature was 6℃, the ammonia nitrogen removal rates of the three strains was 57.7%, 59.0% and 58.7% respectively at the concentration of 5% fungicide.…”