Effects of main factors on remedying northern landscaping water by hybrid ecological filter

Natural zeolite and coal cinder were layered as main packing medium of the ecological filter instead of traditional filling to remedy the static lake water in Northern China.The ecological filter was running in a combined upward and downward flow mode.Dynamic experiments were carried out to study the effects of retention time and ambient temperature on pollutants' removal efficiency of the hybrid ecological filter.The function of plant was also studied by contrast test.It is showed that the removal efficiencies of NH4+-N and TP are increased when the retention time is changed from 1 h to 2 h and 4 h,but the removal efficiency of TN is decreased,the removal efficiency of NH4+-N is increased from 91.5% to 98% and that of TP is increased from 31.8% to 52.5%.When the temperature declines,the temporal removal efficiency of NH4+-N is reduced,but the removal efficiency of 24 h and 48 h is remained.The removal efficiency of TP after 24 h and 48 h is decreased when the temperature declines evidently.The retention time plays an important role in NH4+-N and TP removal,and the ambient temperature is significant for TP removal.The plant favors for TP and organic matter removal but has little effect on TN removal.

Ecological filter walls for efficient pollutant removal from urban surface water

Urban surface water pollution poses significant threats to aquatic ecosystems and human health.Conventional nitrogen removal technologies used in urban surface water exhibit drawbacks such as high consumption of carbon sources,high sludge production,and focus on dissolved oxygen(DO)concentration while neglecting the impact of DO gradients.Here,we show an ecological filter walls(EFW)that removes pollutants from urban surface water.We utilized a polymer-based three-dimensional matrix to enhance water permeability,and emergent plants were integrated into the EFW to facilitate biofilm formation.We observed that varying aeration intensities within the EFW's aerobic zone resulted in distinct DO gradients,with an optimal DO control at 3.19±0.2 mg L^(-1) achieving superior nitrogen removal efficiencies.Specifically,the removal efficiencies of total organic carbon,total nitrogen,ammonia,and nitrate were 79.4%,81.3%,99.6%,and 79.1%,respectively.Microbial community analysis under a 3 mg L^(-1) DO condition revealed a shift in microbial composition and abundance,with genera such as Dechloromonas,Acinetobacter,unclassified_f__Comamonadaceae,SM1A02 and Pseudomonas playing pivotal roles in carbon and nitrogen elimination.Notably,the EFW facilitated shortcut nitrification-denitrification processes,predominantly contributing to nitrogen removal.Considering low manufacturing cost,flexible application,small artificial trace,and good pollutant removal ability,EFW has promising potential as an innovative approach to urban surface water treatment.

Remediation of static lake water by intensified filter of dominant bacteria colony

An ecological filter is constructed for successful nitrification instead of conventional filter system. Zeolite and coal cinder compose main substrates of this micro-ecological filter. Nitrogen contamination removal process is investigated in three different systems (D system, A system and N system) contrastively. Dominant bacteria colony is applied to intensify the remedying process. The data showed that, NH4+-N removal efficiency in D system is better than those in the other two systems for zeolite absorption, nitrogen removal efficiency by nitrification increased. Functional bacterium consortium can adsorb much NH4+-N in short time. Most nitrogen removal is hastened through nitrification by abundant nitrous and nitride bacterium in dominant colony. That dominant consortium keeps high activity in long time. Phosphorus removal is improved by abundant aboriginal bacterium. Complex functional bacterium is benefit to decompose organic phosphorus and its removal.