Combination of Low-Cost Technologies for Pig Slurry Purification Under Semiarid Mediterranean Conditions

Efficiency of an Integrated Purification System for Pig Slurry Treatment under Mediterranean Climate

“…The percentage of removal of over 90% of total suspended solids were in accordance with finding by Vymazal [19] treating sewage with constructed wetlands in an experience of 15 years of operation in the Czech Republic or similar to the results found by Caballero-Lajarín [7] purifying pig slurry in the Region of Murcia, Spain. Transport mechanisms create collisions between particles of suspended solids and binding mechanisms could retain TSS on the substrate [43].…”

“…Results showed that TSS was reduced by 35% with the mechanical separation, previous studies have indicated that a mechanical pretreatment previous the use of HSFCWs avoid clogging of the wetlands and lengthens the life of the system [32]. Caballero-Lajarín et al [7] only achieved 16% of TSS reduction, while Burton [33] pointed out that physical separation can remove up to 80%.…”

“…The horizontal subsurface flow constructed wetland ( Figure 1d) consisted of two cells, each one with an area of 27 × 2.5 m and 1.2 m deep and a bottom slope of 1% ( Figure 2). The porous medium used for filtration was 0.3 m of washed sand, 0.1 m of fine gravel, 0.5 m of coarse gravel and 0.30 m of fine gravel as shown in Figure 2 [7]. One cell was left unplanted as control assessing the effect of the filtration media and the other one was planted with a polyculture of Phagmites asutralis (P. australis) and Suaeda vera (S. vera) with a density of 10 plants m −2 and distributed as 50% of each species testing the filtration media plus plant effects.…”

“…The PS was pumped to a press screw separator ( Figure 1b) with a capacity of 5 m 3 h −1 , then the liquid part was collected in the aerator tank ( Figure 1c) of 10 m 3 staying in this tank for 48 h with an intermittent aeration process, which supplied air through a compressor of 30 m 3 h −1 (Josval, Herraiz, Spain). The retention time on the aerator tank was selected following the indication of other studies [7,21], which used 48 h of retention time in aeration tanks to reduce odors in similar climatic and management conditions than this study. In addition, Zhang and Zhu [23] indicated that short-term and low-intensity aeration is important to generate minimal odor during pig slurry treatment, also contributing to the decomposition of the total and volatile solids and BOD 5 .…”

“…The decrease in the nitrogen concentration was around 10% in the pretreatment modules mainly because of solid/liquid separation. Highlight that the majority of KN in most of the livestock wastewater systems is in inorganic form, mostly as ammonium [7,26,39] and therefore could be adsorbed to the colloids of suspended organic matter. Bernal et al [40] reported that losses of nitrogen ranged from 5% to 60% during storage or composting manure compared with the initial content, which was mainly caused by gaseous emissions of NH 3 [41].…”