Potential Viable Products Identified from Characterisation of Agricultural Slaughterhouse Rendering Wastewater

Abstract

The composition of challenging matrices must be fully understood in order to determine the impact of the matrix and to establish suitable treatment methods. Rendering condensate wastewater is a complex matrix which is understudied. It is produced when the vapour from rendering facilities (heat processing of slaughterhouse waste material) is cooled as a liquid for discharge. This study offers a full physicochemical characterisation of rendering condensate wastewater and its potential for valorisation via production of viable by-products. A study of seasonal variation of levels of dissolved oxygen, chemical oxygen demand, total nitrogen and ammonia was carried out on the wastewater. The results show that the wastewater was high strength all year-round, with a chemical oxygen demand of 10,813 ± 427 mg/L and high concentrations of total Kjeldahl nitrogen (1745 ± 90 mg/L), ammonia (887 ± 21 mg/L), crude protein (10,911 ± 563 mg/L), total phosphorous (51 ± 1 mg/L), fat and oil (11,363 ± 934 mg/L), total suspended solids (336 ± 73 mg/L) and total dissolved solids (4397 ± 405 mg/L). This characterisation demonstrates the requirement for adequate treatment of the condensate before releasing it to the environment. While there is a reasonably constant flow rate and dissolved oxygen level throughout the year, higher chemical oxygen demand, total nitrogen and ammonia levels were found in the warmer summer months. From this study, rendering condensate slaughterhouse wastewater is shown to have potential for production of marketable goods. These products may include ammonium sulphate fertilizer, protein supplements for animal feeds and recovery of acetic acid calcium hydroxyapatite, thus enhancing both the financial and environmental sustainability of slaughterhouse operations. This work demonstrates a valuable assessment of a complex wastewater, while taking advantage of on-site access to samples and process data to inform the potential for wastewater reuse.

Multi-Integrated Systems for Treatment of Abattoir Wastewater: A Review

“…The accumulation of particulates such as fats, grease, protein, and organic matter can cause build-up on the membrane material resulting in membrane fouling and wetting which is a huge economic influence on the use of membranes as they account for 72% of the capital investment [10]. The types of foulants which may interfere with membrane performance include chemical foulants such as scaling, physical foulants such as deposition of particles, biological foulants such as microbes, and organic foulants which interact with the membrane material [79].…”

Potential ecological risk assessment of heavy metals associated with abattoir liquid waste: A narrative and systematic review

“…The presence of Mn in liquid effluent from slaughtering operations has been reported in several investigations [ 15 , 47 ]. Mn toxicity and associated human health risks ( Table 2 ) have been documented [ 46 ].…”

Effect of Temporal Variation in Chemical Composition on Methane Yields of Rendering Plant Wastewater

“…On the other hand, no significant difference (p ≥ 0.05) was noticed for TKP content, except for Day 4 (p ≤ 0.004). Such differences in chemical composition in daily samples are associated with the variation in abattoir waste materials received by rendering facilities and also attributed to the presence of non-edible residues such as skinning residuals, blood content and intestinal components, which is dependent on the type of animal slaughtered at the abattoirs [16,34].…”