The management of waste wash-water (WWW) is one of the most significant environmental problems associated with ready-mix concrete production worldwide. The problems are exacerbated should it be disposed of in an inappropriate manner. This study evaluated the potential of WWW recycling in ready mix concrete plants in Jordan. A representative waste wash-water sample (400 L) was collected from a basin in a ready-mix concrete company. A pilot plant on the lab scale was fabricated and installed. The treatment system consisted of a concrete washout reclaimer, wedgebed slurry settling pond, slow sand filtration unit, and a neutralization unit. Water samples were collected from all stages of the pilot plant and analyzed. The collected waste wash-water samples were utilized for replacement of well water (mixing water) at various ratios. Fourteen concrete mixtures were produced and cast, as well as tested at various curing ages (7, 28, and 90 days). The results show that the raw WWW was not acceptable as mixing water even after dilution as it led to significant reductions in concrete compressive strength and low workability. However, the WWW from the settling pond, the filtered WWW and the filtered-neutralized WWW at dilution ratios up to 75% were shown to be potential alternatives to fresh water for ready-mixed concrete. Therefore, the current guidelines for mixing water quality should be revised to encourage the reuse of the WWW.

中文翻译：

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预拌混凝土厂中的废洗水回收

废水冲洗（WWW）的管理是与全世界预拌混凝土生产相关的最重要的环境问题之一。如果处理不当，问题将会更加严重。这项研究评估了约旦预拌混凝土工厂中WWW回收的潜力。从预拌混凝土公司的一个水池中收集了一个有代表性的废水洗涤样品（400升）。实验室规模的中试工厂已安装完成。该处理系统由混凝土冲洗回收机，楔形泥浆沉淀池，慢速砂滤装置和中和装置组成。从中试工厂的所有阶段收集水样并进行分析。收集的废水洗涤水样品被用于以各种比例替换井水（混合水）。生产并浇铸了14种混凝土混合物，并在各种固化时间（7、28和90天）下进行了测试。结果表明，即使稀释后，原始的WWW也不能作为混合水使用，因为它会导致混凝土抗压强度显着降低和可加工性低下。但是，来自沉淀池的WWW，过滤后的WWW和过滤后的中和的WWW（稀释比高达75％）被证明是预拌混凝土的淡水替代品。因此，应修订当前的混合水质量准则，以鼓励WWW的重复使用。结果表明，即使稀释后，原始的WWW也不能作为混合水使用，因为它会导致混凝土抗压强度显着降低和可加工性低下。但是，来自沉淀池的WWW，过滤后的WWW和过滤后的中和的WWW（稀释比高达75％）被证明是预拌混凝土的淡水替代品。因此，应修订当前的混合水质量准则，以鼓励WWW的重复使用。结果表明，即使稀释后，原始的WWW也不能作为混合水使用，因为它会导致混凝土抗压强度显着降低和可加工性低下。但是，来自沉淀池的WWW，过滤后的WWW和过滤后的中和的WWW（稀释比高达75％）被证明是预拌混凝土的淡水替代品。因此，应修订当前的混合水质量准则，以鼓励WWW的重复使用。