Experience of Application of Natural Treatment Systems for Wastewater (NTSW) in Livestock Farms in Canary Islands

Abstract

A real-scale application experience Natural Treatment Systems for Wastewater (NTSW) operating in continues with livestock farms for one year. These systems are based on digesters, subsurface vertical flow constructed wetlands (SVFCW) and facultative ponds. Chemical Oxygen Demand removal efficiency (CODRE) has obtained between 70 and 90%. Likewise, it have been possible to compare the operation of cascade flow digesters (CFD) (<76% CODRE) versus complete mixing digesters (CMD) (<50% CODRE). Facultative ponds (FP) when combined with (SSFCW), removed a higher percentage of CODRE compared with ponds (92%). Correlations of interest have been found between the variables evaluated in each plant. Finally, different elements are alternated in the same system, this system is capable of supporting variations in changes in flow rate and organic load coming from the farm, maintaining an adequate elimination of COD and other parameters of interest.

A Tool for Effluent Characterization and Design of Natural Treatment Systems for Wastewater (NTSW) for Livestock Farms with High Organic Load in Isolated Island Environments.

“…The treatment is carried out by passing the effluent through various types of ponds, artificial wetlands and anaerobic digesters, each of which facilitates a series of natural processes. Such systems have been successfully applied in rural community settings and small settlements with a population equivalent below 1000 [1,2,28]. However, when it comes to sizing such systems, there are no tools available for agricultural and livestock farms in isolated territories, with sizing limited to adaptations based on local farmer experience [29 -30].…”

“…For the application of the NTSW, the starting point was the articles [1,28] which study three livestock farms, one of which is our reference farm [2]. The criteria used for the design were the characteristics of the farms, Q, COD and EC.…”

“…For the application of the NTSW, the same rotary sieve (50mm) has been applied (and in the case of the digester and ponds plus wetlands, based on the data obtained in these articles, their behavior has been studied according to the needs of the farms studied [1,2,28]. The digester is more suited for a high removal of COD 2.33 %/day and ponds plus wetlands system is more suitable for a removal of EC 1.5%/day [2,28]. To start, set the number of sows of the farm, set a depuration target (measured in COD and EC reduction) and characterize the waste generated, Q, COD, EC, NT, NH3.…”

“…From [2,28] the characteristics of the farms, where they are located, flow, COD, EC and according to current local legislation sets a maximum discharge target of 1600 mg/L COD and 2500 μS/cm EC the NTSW sizing has been proposed for each farm.…”

Climate Change Mitigation Tool Implemented through an Integrated and Resilient System to Measure and Monitor Operating Variables, Applied to Natural Wastewater Treatment Systems (NTSW) in Livestock Farms

“…As reported in different studies, one way of treating said waste is to employ a Natural Treatment System for Wastewater (NTSW) on the livestock farm itself, either through anaerobic digestion or the use of constructed wetlands and lagoons [23][24][25][26]. However, it has been studied that these systems generally operate in less-than-optimal conditions, mainly due to the lack of online data of the operating parameters, which translates into lower performance.…”