颗粒滤料在化学澄清处理中的应用实践“扫絮” 凝结会在较长时间内在过滤介质上获得金属表面涂层 时间的问题。本质上，金属氢氧化物絮体从沉淀池和 这些氢氧化物絮体在过滤介质上多年的老化导致 过滤介质上的耐用金属氧化物涂层，有助于提高NOM 以及在整个过滤器运行周期内的砷吸附。这项总体研究的目标 目的是量化天然有机物（NOM）和使用天然涂层去除砷 来自传统快速过滤器的沙子。本文的主要研究目标是: 将溶解有机碳（DOC）和紫外线（UV）吸附（254 nm）作为 金属表面涂层的功能（即铝基涂层与铁基涂层）- 基于）的pH值 再生过滤介质反洗（BW）溶液，进水pH值NOM挑战 解决方案，并挑战水质。 初步结果表明，DOC和UV吸光度去除率显著降低 随着BW再生pH值（高达pH值10-12）的增加和挑战的降低而增强 溶液pH值。将pH值增加到13会导致铝的显著损失 涂层和相应减少的DOC去除。进水挑战解决方案 pH值对DOC去除效率有重要影响。BW再生是 在该阶段保持pH 11，同时将进水pH调节至6、5和4。 DOC和UV吸光度的去除率随着温度的降低而显著增加（>80%） pH值。在较低pH值的运行终止时，DOC去除率至少具有可比性，如果 不超过使用商用熨斗记录的清除量- 氧化物涂层砂。包括7篇参考文献。

Granular filter media used in chemical clarification treatment practicing "sweep floc" coagulation will acquire metal surface coatings on the filter media over extended periods of time. In essence, the metal hydroxide floc carryover from the settling tanks and the aging of these hydroxide floc on the filter media over years of exposure have resulted in a durable metal-oxide coating on filter media that can be conducive for enhanced NOM and arsenic adsorption over the entire filter run cycle. The objective of this overall study was to quantify natural organic matter (NOM) and arsenic removal using naturally coated sands from conventional rapid rate filters. The major research goals of this paper were to evaluate dissolved organic carbon (DOC) and ultraviolet (UV) adsorbance (254 nm) as a function of metal surface coating (i.e. aluminum-based vs. iron-based), pH of regenerating filter media backwash (BW) solution, pH of the influent NOM challenge solution, and challenge water quality. Preliminary results indicate that DOC and UV absorbance removals were significantly enhanced with increasing BW regeneration pH (up to pH 10-12) and lower challenge solution pH. Increasing the pH to 13 resulted in a significant loss of the aluminum coating and a corresponding decrease in DOC removal. The influent challenge solution pH had an important impact on DOC removal efficiency. The BW regeneration was maintained at pH 11 during this phase while the influent pH was adjusted to 6, 5, and 4. DOC and UV absorbance removals were dramatically increased (>80%) with decreasing pH. At run termination at the lower pHs, DOC removals were at least as comparable if not exceeding removals noted using commercially available iron-oxide coated sands. Includes 7 references.