Sludge treatment beds (STBs) have been used widely in many countries due to low energy consumption, low operating and maintenance costs, and better environmental compatibility. Penetration, evaporation, and transpiration are the main processes for sludge dewatering in STBs. However, the leachate quality from STBs usually cannot meet discharge limits. Moreover, such leachate has very low COD/N ratio, which makes it difficult to treat. In the present study, two subsurface flow (SSF) constructed wetlands (CWs) were investigated for the treatment of leachate from STBs under three different hydraulic retention time (HRT) (3 days, 4 days, 6 days), aiming for evaluating the effects of plants and HRT on treatment performance, as well as the potential of SSF CWs to treat sludge leachate with low COD/N ration. The results showed that plants play an important role in leachate treatment. The best treatment performance was achieved with HRT of 4 days. In this condition, the mean removal efficiencies of COD (chemical oxygen demand), NH4+-N, TN (total nitrogen), and TP (total phosphorus) in the planted and the unplanted CWs were 61.6% (unplanted - 3.7%), 76.6% (unplanted 43.5%), 70% (unplanted 41%), and 65.6% (unplanted 6%), respectively. Heavy metal concentrations were below the Chinese integrated wastewater discharge standard during the experimental period in the planted CW, and the removal efficiencies in the planted CW system were higher than in the unplanted CW system. In all, planted SSF CWs can be an effective approach in removing leachate from sludge treatment beds. Furthermore, considering to temperature and seasonal variation, the leachate from STBs needs to be further studied in pilot- and full-scale condition.

• Klíčová slova
• Constructed wetland, Sludge leachate, Sludge treatment beds, Water purification,
• MeSH
• čištění vody MeSH
• dusík analýza   MeSH
• fosfor analýza   MeSH
• látky znečišťující vodu analýza   MeSH
• měření biologické spotřeby kyslíku MeSH
• mokřady * MeSH
• odpad tekutý - odstraňování metody   MeSH
• odpadní voda MeSH
• odpadní vody MeSH
• rostliny MeSH
• těžké kovy MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• dusík MeSH
• fosfor MeSH
• látky znečišťující vodu MeSH
• odpadní voda MeSH
• odpadní vody MeSH
• těžké kovy MeSH

Sewage sludge treatment is becoming one of the most significant challenges for domestic wastewater management. Optimization of sludge management for reducing sludge handling cost in wastewater treatment plant is highly demanded. Sludge treatment reed bed system (STRB) is an eco-environmentally friendly technology which has a low investment input and reduced costs for operation and maintenance. The objective of this study is to evaluate the effect of earthworm assistant STRB in terms of sludge dewatering and stabilization of surplus sludge. The results show that draining and evapotranspiration (ET) take the main role for sludge dewatering; with maximum of 77 and 43 % water was removed through draining and ET, respectively. Plants improved ET rate up to 13.1 % in the planted STRB compare with the unplanted STRB. The combination of plants and earthworms increased ET rate of 20.9 % more than the control STRB (unplanted without earthworms). The planted STRB with earthworm reached the lowest water content in accumulated sludge of 46 %. There was a systematic increase of total solids (TS) concentration from 0.5 % in the influent to 25-54 % in the accumulated sludge. Earthworms enhanced the sludge stabilization dramatic with the ratio of volatile solids (VS)/TS decreased from 49 % in the influent to 18 % in the accumulated sludge in the earthworm assistant STRB. The results demonstrated a good efficiency for sludge dewatering and stabilization with the assistant of earthworms in STRBs, which can be an alternative technology for sludge treatment in wastewater treatment plants.

• Klíčová slova
• Earthworms, Sludge dewatering, Sludge stabilization, Sludge treatment reed bed system,
• MeSH
• kvalita vody MeSH
• mokřady * MeSH
• nakládání s odpady metody   MeSH
• odpadní vody * MeSH
• Oligochaeta fyziologie   MeSH
• voda MeSH
• zázvorníkotvaré * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• Názvy látek
• odpadní vody * MeSH
• voda MeSH