Biological Contact Oxidation: How to Size the Filler, Set the Air-Water Ratio and Keep the Bed From Clogging

2026-09-24

A designer's view of biological contact oxidation: selecting honeycomb filler pore size from BOD5 and suspended solids, setting contact time, dissolved oxygen and air-water ratio, and understanding why direct and split-flow aeration produce very different

Activated Sludge Operation: Loading Rate, Aeration Geometry and the Choices Behind Stable Effluent

2026-09-24

What governs an activated sludge plant: the two reaction stages inside the aeration tank, how F/M loading trades capital and operating cost against effluent quality, and how tank geometry and aeration hardware change the answer. Covers conventional, high-

Biofilm Reactor Selection: Film Thickness, Carrier Hydraulics and the Sloughing Cycle That Governs Performance

2026-09-24

How fixed-film reactors actually work: the layered structure running from carrier to bulk water, why the aerobic film stays around 2 mm, the hydraulic loading thresholds that separate ordinary beds from high-rate ones, and why sloughing is a design variab

Reverse Osmosis Sizing: Pressure Balance, Transport Models and What Element Specs Really Tell You

2026-09-24

A practical walk through reverse osmosis: where the driving force comes from, how the competing transport models were finally reconciled, and which element specifications genuinely predict plant performance. Covers osmotic pressure, the flux relationship,

Printing and Dyeing Wastewater: Where the Load Comes From and Why Biology Struggles

2026-09-23

A stream-by-stream breakdown of printing and dyeing effluent, from desizing and mercerizing to alkali peeling, the composite quality envelope plants actually see, and why adsorption and biology both fall short.

Membrane Fouling: Sorting Precipitation, Organic Adsorption and Biofilm Before Choosing a Clean

2026-09-23

Fouling is rarely one problem. This piece separates precipitation, organic adsorption, gel-layer formation and biofouling, explains why hydraulic cleaning fails on each, and covers the chemical controls that actually extend a run.

The Anaerobic Baffled Reactor: Phase Separation in One Tank and What It Costs You

2026-09-23

How vertical baffles split acidogenesis from methanogenesis inside a single shell, the geometry and loading rules that govern performance, the start-up strategies, and the process combinations ABR is normally dropped into.

Anammox Bacteria: The Slow-Growing Autotrophs That Cut Aeration and Carbon Demand

2026-09-23

How anammox bacteria convert ammonia and nitrite straight to nitrogen gas, the hydrazine and hydroxylamine chemistry inside the anammoxosome, the six known genera, and what full-scale SHARON, CANON and EGSB combinations have achieved.

Ammonia Nitrogen: What the Number Means and How the Common Methods Actually Measure It

2026-09-23

Ammonia nitrogen is really three species with different toxicity. This piece covers the speciation, the ammonia-sensitive electrode method, Nessler colorimetry, reagent make-up, and the detection limits each route reaches.

Iron or Aluminium? Choosing and Dosing Flocculants Without Wasting Chemical

2026-09-23

A field guide to the iron-based and aluminium-based flocculant families, what the polymer acronyms actually mean, how to make down and meter solutions, and the mixing energies each coagulation stage needs.