The increase in natural water bodies pollution caused by intensive animal farming requires the development of innovative sustainable treatment processes. This study assessed the influence of piggery wastewater (PWW) load, air dosing, CO2/NaHCO3- supplementation and pH control on PWW treatment by mixed cultures of purple phototrophic bacteria (PPB) under infrared radiation in batch photobioreactors. PPB was not able to grow in raw PWW but PWW dilution prevented inhibition and supported an effective light penetration. Despite the fact that PPB were tolerant to O2, carbon recovery decreased in the presence of air (induced by stripping). CO2 supplementation was identified as an effective strategy to maximize the removal of carbon during PPB-based PWW treatment with removal efficiencies of 72% and 74% for TOC and VFAs. However, the benefits derived from CO2 addition were induced by the indirect pH control exerted in the cultivation medium. Thus, PPB supported an optimal pollutant removal performance at pH 7, with removal efficiencies of 75%, 39% and 98% for TOC, TN and VFAs.

中文翻译：

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紫色光养细菌处理猪场废水的系统优化。

集约化畜牧业造成的自然水体污染的增加要求开发创新的可持续处理方法。这项研究评估了批次光生物反应器中紫色光养细菌（PPB）在红外辐射下的混合培养对猪废水（PWW）负荷，空气剂量，CO2 / NaHCO3-的补充和pH控制对PWW处理的影响。PPB不能在原始PWW中生长，但PWW稀释可防止抑制并支持有效的光穿透。尽管PPB耐受O2，但在空气存在下（通过汽提引起）碳回收率下降。补充二氧化碳被认为是在基于PPB的PWW处理过程中最大程度地去除碳的有效策略，TOC和VFA的去除效率分别为72％和74％。然而，通过间接地控制培养基中的pH值，可以从添加二氧化碳中获得好处。因此，PPB在pH为7时具有最佳的污染物去除性能，对TOC，TN和VFA的去除效率分别为75％，39％和98％。