1,721,128 research outputs found
Influence of annual climate variability on the design of waste stabilisation ponds for continental climates
WSPs are widely used in North America, and offer huge potential for other continental climate regions. The standard design and operating protocol is robust even at high latitudes, but may be conservative elsewhere. A simple model based on first-order kinetics for biochemical oxygen demand (BOD) is used to consider some alternative design and operating protocols, using long-term daily climate records for cities across continental central Asia. Options include changing the discharge period; retaining treated water in the pond over the winter; and changing the facultative pond loading. Annual variability in climate parameters has a major effect, in particular on the date at which treated wastewater meets appropriate standards for discharge or re-use: the earlier the discharge, the greater the variability in effluent quality. Skilful management of these systems may therefore be required to maximise their performance. While current models require development, it is clear modelling could provide tools and guidelines that would allow the design of continental climate WSP to be tailored to specific regional and local climate condition
Effect of increasing the organic loading rate on the co-digestion and mono-digestion of cattle slurry and maize
Operation and recovery of a seasonally-loaded UK waste stabilisation pond system
An intermittent discharge waste stabilisation pond system was trialled for treatment of a seasonal wastewater load from a campsite. The system showed rapid acclimatisation to incoming load, with chlorophyll-a exceeding 700 mg l?1 within 2 weeks and filtered and unfiltered effluent biochemical oxygen demand below 20 and 30 mg l?1 respectively. Good performance continued for some weeks, after which photosynthetic oxygenation capacity in the first pond was seriously impaired by a shock loading believed to include fatty material. Inflow to the system was suspended and a surface film was broken up, after which the pond recovered within an 8-day period. Laboratory experiments indicated that interventions such as artificial aeration and dilution with effluent had no beneficial effect although mixing may have increased the rate of recovery
BG educational initiative in Kazakhstan- Professional preparation for specialists in environmental management
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