Anaerobic digestion is a biological process that can partially convert organic matter into gases with potential to energy generation. However, in case of continuous stirred tank reactor (CSTR) for the treatment of sludge from swine manure, a digestate with a high concentration of solids, undigested carbon, nitrogen and phosphorus is usually obtained, which can limit the direct application to the soil or other direct uses or disposal. Therefore, an additional treatment of digestate is still needed to meet environmental requirements for the viability of an anaerobic digestion plant to enable the disposal of the liquid effluent. In this study, solid-liquid separation (SLS) strategies were studied for treatment of digestate from swine sludge CSTR biodigester. The following processes were tested: settling, centrifugation and chemical flocculation.The performance of each process was evaluated by monitoring the concentrations of the following parameters in the raw digestate and after treatment: total carbon (TC), phosphorus, total kjeldahl nitrogen, ammonia nitrogen, total solids (TS), volatile solids and fixed solids. The factorial design was used for the optimization of centrifugation and chemical flocculation tests. Total carbon, solids and phosphorus were significantly reduced from digestate using the different SLS processes. However, higher removal efficiencies were obtained by centrifugation, being more expressive to phosphorus, TC and TS (reduction of 95, 90 and 83%, respectively). Furthermore, the sludge production by centrifugation was 3.8 and 7.3 times lower than by settling and chemical flocculation, respectively. Thus, centrifugation could be considered the most appropriate SLS process to enable digestate treatment and the liquid efluent is suitable to be treated by deammonification process for nitrogen removal.

中文翻译：

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处理来自猪污泥连续搅拌釜反应器的消化物以降低总碳和总固体含量

厌氧消化是一种生物过程，可以将有机物质部分转化为具有发电潜力的气体。然而，在处理猪粪污泥的连续搅拌釜反应器（CSTR）的情况下，通常会得到含有高浓度固体、未消化的碳、氮和磷的消化物，这会限制直接应用于土壤或其他直接使用或处置。因此，仍然需要对消化物进行额外的处理以满足厌氧消化装置的生存能力的环境要求，从而能够处理液体流出物。在这项研究中，研究了固液分离 (SLS) 策略用于处理来自猪污泥 CSTR 生物消化器的消化物。测试了以下过程：沉降、离心和化学絮凝。通过监测原料消化液和处理后以下参数的浓度来评估每个过程的性能：总碳 (TC)、磷、总凯氏氮、氨氮、总固体 (TS)、挥发性固体和固定固体。析因设计用于优化离心和化学絮凝试验。使用不同的 SLS 工艺，消化物中的总碳、固体和磷显着减少。然而，通过离心获得更高的去除效率，对磷、TC 和 TS 的表达能力更强（分别减少 95%、90% 和 83%）。此外，离心产生的污泥比沉降和化学絮凝分别低 3.8 和 7.3 倍。因此，